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Physiology

Why some Olympians restrict their blood flow to train better – CNN

The origins of this practice go back to 1966, when -- while sitting on his heels during a Japanese temple ceremony -- Yoshiaki Sato noticed his calves felt tingly and pumped up. Sato wondered if his limited blood flow was the key to experiencing that sensation, said Steven Munatones, the CEO of KAATSU, an eponymous blood flow restriction product and education company. Munatones cofounded KAATSU Global -- which translates to "additional pressure" in English -- with Sato in 2014 after being mentored by him about the Kaatsu technique for 13 years in Japan.

Seven years after that initial tingly feeling, Sato "experimented with different kinds of bands placed on different locations on his body -- from his head to his torso to his lower legs," Munatones said via email. "In 1973, he experienced a broken ankle and rehabilitated himself using KAATSU."

This was the first experimentation with KAATSU cycle mode, Munatones added, which is when bands with internal "air bladders" are inflated for 30 seconds as the bands compress around upper limbs, then deflate for five seconds before repeating the cycle. This rhythmic compression slows the blood flow back to the heart and therefore allows the veins and capillaries in the treated areas to engorge with blood -- visible as the skin gradually reddens -- while you're exercising, Munatones said.

"Individuals exercise during the application of BFR to improve muscle mass, muscle strength, reduce pain, improve recovery, increase cardiovascular capacity and augment sports performance," said physical therapist Nicholas Rolnick via email.

How it works

When someone exercises while practicing Kaatsu or blood flow restriction, blood and metabolic byproducts are "stuck in the muscle, unable to leave," Rolnick said.

"The metabolites increase muscle fatigue, causing the muscle to work much harder than it normally would to produce a contraction at light loads," he added. "We have to work very hard to keep up with the exercise and that extra effort, paired with the fatigue produced through the BFR, accelerates muscle mass and strength gains."

Muscle fibers required to perform high-intensity actions -- such as jumping, throwing, lifting weights or kicking -- are recruited at lower intensities than usually required, said Stephen Patterson, a professor in applied exercise physiology and performance at St Mary's University, London, via email. That means someone could lift 20% to 30% of their maximum weight instead of the usual 70% or greater, and still experience a response like that of training with heavier loads, he added.

Need-to-knows before attempting BFR

People these experts have sold related products to, treated or studied include athletes of nearly all levels of ability, people who lead sedentary lifestyles, and those recovering from injuries, and range from 18 years old to 104.

The ability to use much lower loads when blood flow restriction training to build muscle and increase strength "is especially beneficial for those who are injured or have other conditions that do not allow them to either lift heavy or perform high intensity aerobic exercise," Patterson said. This includes people who have recently had surgery or are paraplegic or quadriplegic.

"Major problems in the rehabilitation setting are the inability for patients to effectively strength train due to an injury or post-surgical precautions as well as pain," Rolnick said. "The growth of BFR training allows those individuals who would be unable to challenge their bodies under normal circumstances a chance to build more strength and muscle mass during times where it would be near impossible."

If you have just had surgery and have large incisions with stitches and you want to practice Kaatsu immediately, talk to your doctor first, Munatones said. "The reason why is because the incision will dramatically heal much, much faster than normal and their skin can grow very quickly over their stitches - which usually surprises orthopedic surgeons how quickly the body recovers using KAATSU."

Groups for whom blood flow restriction might not be appropriate include people with hypertension, uncontrolled diabetes, obesity, kidney disease, arterial calcification, a history of blood clots and medications or conditions causing higher risk of clotting, venous thromboembolism, vascular diseases, sickle cell anemia, cancer, poor circulatory systems or open fracture, these experts said.

Potential side effects have included lightheadedness, tiny red spots on arms, bruising near the equipment, feelings of pins and needles, and nerve damage, some of which can be avoided by properly practicing blood flow restriction.

Contact your doctor before trying this type of training, or if you experience these or other negative side effects.

How to practice the technique

Regarding equipment, Patterson recommended using medical grade-type products that will give you a reading to ensure the pressures advertised are true. "Exercise bands and other material etc. may be able to restrict blood flow but from a safety perspective there is no idea what level of restriction you are applying," he wrote via email. That could limit adaptations and responses or cause injury.

"There are many cuffs on the market but my line in the sand is a pneumatic cuff that can be inflated either automatically or manually (like a blood pressure cuff)," Rolnick said. "Each of these types of cuffs can carefully measure the amount of blood is restricted to increase safety profile. This is very important because as BFR continues to grow, more cuffs are going to enter the marketplace that may not be adequate or appropriate."

Rolnick and Patterson advised anyone starting out with blood flow restriction to work and train with trusted practitioners to determine what cuffs would be consistent with your goals -- and to understand how and when to use this type of training. Otherwise, Rolnick added, you could be at higher risk of experiencing a negative outcome -- especially since an ordinary exercise band can't measure how much pressure you're applying.

You can expect burning sensations or soreness during or after the first couple of sessions, but these generally subside by the third session, said Hunter Bennett, a lecturer in exercise science at the University of South Australia, via email.

Once you inflate the cuff, you could practice blood flow restriction by alternating repetitions and rest while training your preferred muscle group, Bennett said.

The consensus among these experts is that using blood flow restriction two to four times a week is required for results to occur.

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Why some Olympians restrict their blood flow to train better - CNN

Physiology

The secrets of the Alps’ strange red snow – BBC News

The secrets of the Alps' strange red snow

(Image credit: Bob Gibbons/Alamy)

Growing patches of coloured snow in the French Alps could be a sign of the impact climate change is having in the mountains.

I

It is a shocking, garish sight to come across on a peaceful mountainside. Hike high enough in the French alps during the late spring and early summer, and there is a good chance thatyou will come across some rather strange patches of snow among the grey limestone and stunted clumps of vegetation. This snow isn't white it's blood red.

The peculiar phenomenon sometimes known as blood snow is the result of a defence mechanism produced by microscopic algae that grow in the Alpine snow. Normally these microalgae have a green colour as they contain chlorophyll, the family of pigments produced by most plants to help them absorb energy from sunlight.However, when the snow algae grow prolifically and are exposed to strong solar radiation, they produce red-coloured pigment molecules known as carotenoids, which act as a sunshield to protect their chlorophyll.

While red snow algaehas been known for a long time (it is mentioned in a book published in 1819 as having been discovered during an expedition to the Arctic in 1818) it is still steeped in mysteries that scientists are attempting to unravel.

Just two years ago, botanists at Charles University, Prague, in the Czech Republic, identified an entirely new genus of microalgae that is responsible for causing red and orange snow in different parts of the world, which they named "Sanguina" in reference to the blood-red colour they produce. The researchers found forms of Sanguina algae that cause red snow samples from Europe, North America, South America along with both polar regions. A species of Sanguina that causes an unusual orange snow was also found in Svalbard.

Researchers discovered a new genus of algae called Sanguina that is responsible for the red snow in the French Alps above 2,400 metres (7,874ft) (Credit: ALPALGA)

It isn't the only type of microalgae responsible for red snow though. Several other types, such as Chlamydomonasnivalis and an algae found growing close to Antarctic penguin colonies called Chloromonas polyptera, also produce pigments to create red and pink stained snow.

But understanding more about red snow algae carries a significance far greater than simply explaining the existence of strange-coloured patches in the Alps and near the poles. Its appearance and disappearance are important markers of climate change and how it is affecting the delicate ecosystems where the algae are found.

According to Liane G Benning, professor of interface geochemistry at the German Research Centre for Geosciences in Potsdam, red snow is becoming more common due to global warming. "The rise in the atmospheric carbon dioxide levels increases the temperature, which leads to more snow melting," she says. "The moment there is liquid water on the snow, the algae start growing."

This increasing abundance of red snow algae may also be contributing to climate change too. The red pigment turns the snow surface dark, reducing the amount of light and heat it reflects back into space something known as the albedo effect. By trapping more of the Sun's heat, the snow melts even faster, allowing the algae to proliferate further. "There is a runaway effect in which the algae melt their preferred habitat," says Benning. "Its as if they are destroying their own house."

On a wider scale, the extra heat absorbed by the tinted snow can alter the temperature in the wider environment, speeding up the melting of snow packs and glaciers. One study estimated that over a single melt season, red pigmented algal blooms could reduce the snow albedo by 13%, suggesting it plays an important role in how the effects of climate change can be amplified within mountain environments.

Studies have shown red algal blooms occur on glaciers all over the world, from Antarctica to the Himalayas and in the Arctic. So one question that scientists like Benning and Eric Marchal, director of the Cell and Plant Physiology Laboratory in Grenoble, France, are keen to answer is whether red snow algal blooms are becoming more widespread and occurring more often.

One way of doing this would be to use satellite imagery to study the albedo-reducing effect of the red snow. A study using satellite imagery of snow fields on Fildes Peninsula on King George Island, off the coast of Antarctica, revealed that in January 2017, 26% of the snow was darkened by algae.

Although there is little widespread data to show if red algae are becoming more common globally, both Benning and Marchal believe they will occur more often as our planet warms, and this will need to be taken into account as scientists try to estimate what the impacts will be.

But even laying aside their role in climate change, scientists are unpicking other mysteries surrounding red snow.

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Marchal and his colleagues recently found that red snow algae appear to only grow at elevations above 2,000m (6,562ft) in the French Alps, and particularly flourish at around 2,400m (7,874ft). According to Marchal, the Sanguina algae is found at high elevations because of the quantity, quality and longevity of the snowpacks present at these heights.

Puzzlingly, scientists have so far failed to grow these algae on real snow in a laboratory.

"It is for this reason that researchers need to collect as many samples as possible for a more refined study," Marchal says.

Algae that grow close to penguin colonies near Antartica produce vivid red pigments (Credit: Robert Harding/Alamy)

During a recent two-day expeditionto the Lautaret pass in Hautes-Alpes, southeastern France, in June this year Marchal and his colleagues in the ALPALGA consortium of five French institutes dedicated to the study of mountain algae, collected their first samples of 2021. Unlike previous years, however, the snow didn't have its typical red hue. Instead, it was dominated by ochre yellow.

The yellow tinge, they believe, was due to the presence of sand on the snow that interfered with the colour imparted by the algae. While not an unusual phenomenon, this year was exceptional as strong winds carried plenty of Saharan sand to the Alpine heights.

"This has provided us a great opportunity to evaluate the relationship between sand and the growth of snow algae," says Marchal. "By analysing these particles, we will try to determine if sand provides nutrients, metals or any specific elements that may interfere, positively or negatively, with the algae growth."

The team hopes to increase the ambit of their understanding to see how iron levels in the snow and acidity levels affect the red algae growth. They are also studying whether other microorganisms and animals living alongside the snow algae may play a role.

Glaciologists fear that if the algae spreads it will decrease the albedo of the snow and drive further melting of snowpacks in mountain ranges around the world (Credit: ALPALGA)

According to Marchal, the first tests on the new samples collected in June have revealed the presence of unicellular animals, called zooplankton, with the algae cells. Although more normally associated with oceans and lakes, where they form a key element of the food chain, zooplankton can also survive in the meltwaters from glaciers and snow packs.

Their research is helping to build a picture that although snow might appear to be inert, it is in fact teeming with life.

"As snow falls, quite often it traps minerals and elements like nitrogen and phosphorus, both anthropogenic and naturally occurring," Benning says. The snow algae can then feed on these while bacteria in the snow also form a trophic relationship with the algae.

"In this ecosystem, the snow algae are primary producers," says Benning. "When they bloom, they photosynthesise, consume nutrients while producing waste products such as sugars and other components, which serve as possible food for bacteria and other microorganisms."

In some places the algae can produce a faint pink colour to the snow while in others it can be blood red (Credit: Ashley Cooper Pics/Alamy)

According to Marchal, the algae, which need just carbon dioxide and light, appear to form the basis of a more complex and mature ecosystem that involves bacteria, fungi and unicellular animal cells such as the zooplankton.

But while these patches of coloured snow flourish with life they are also short lived, appearing only for a few weeks of the year. When the weather turns cold again, the colour disappears and the snow returns to its usual white colour.

It raises an intriguing question what actually happens to the red algae over the winter?

"One theory is that they go dormant and become almost transparent as they freeze in," says Benning. "When it's no longer needed, they lose the pigmentation as it is an energy consuming process."

While the red pigment returns each year with the sunshine and heat of the late spring and early summer, Benning and her fellow scientists will be watching the stains in the snow closely for what else they can teach us.

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The secrets of the Alps' strange red snow - BBC News

Embryology

Mississippi Asks SCOTUS to Overturn Roe | Josh Hammer – First Things

Next term, the Supreme Court will hear Dobbs v. Jackson Womens Health Organization, the case concerning Mississippis statutory 15-week gestational ban on most abortions. Dobbs represents the best chance in decades for a legal breakthrough in the fight against abortion. Earlier this month, Robert P. George wrote that in Mississippis Dobbs brief, Mississippi Attorney General Lynn Fitch should call for the overturning of Roe v. Wade and its progeny, Planned Parenthood v. Casey.

Her brief is due on July 22, George wrote on July 1. And if Attorney General Fitch waters down her arguments to the Court, contrary to her duties to the state, to the pro-life voters who elected her, and to the causes of justice and the rule of law, there must be a severe political reckoning.

That brief has now been filed, and Fitch has delivered the goods. RoeandCaseyare . . . at odds with the straightforward, constitutionally grounded answer to the question presented [in this case], Fitch wrote last Thursday on behalf of her client, the Magnolia State. So the question becomes whether this Court should overrule those decisions. It should.

Bravo. This is outstanding news.

Sherif Girgis has argued that upholding Mississippis law on narrow grounds, in such a way that Roe and Casey are not themselves disturbed, would be exceedingly difficult if not impossible. The duly enacted Mississippi statute challenged in Dobbs is indeed at loggerheads with Roe and Casey, as both Robert George and Ed Whelan have argued. Anything less than a clarion call from Mississippis leading advocate to overturn those cases standing in the way of upholding that statute would have represented a dereliction of duty.

Fitch deserves credit not merely for her admirably pellucid language about Roe and CaseyRoe and Casey are egregiously wrongbut also for her strong contention that traditional stare decisis norms ought not to prevent the actual overturning of these deeply flawed constitutional precedents. As Michael Stokes Paulsen and I (among others) have argued, judicial reliance upon stare decisis norms in constitutional interpretation in our system of governance is not merely contrary to sound principles of judging: For the most part, such reliance is actually unconstitutional.

While stare decisis in English common law developed as an indispensable and conservative doctrine based in historical empiricism and epistemological humility, its operation in the context of United States constitutional interpretation is not at all analogous to that distant English forebear.

Under the Constitutions Article VI Oath Clause, all legislative, executive, and judicial officers of both the federal and state governments vow to support this Constitutionnot this Constitution as nine justices have interpreted it or misinterpreted it, but this Constitution. Period. As I argued last year: For the same reason the Article VI Oath Clause instructs a judge to prefer the Constitution tostatutesrepugnant theretothe crux of Chief Justice Marshalls 1803 ruling in Marbury v. Madisonso too does it necessarily instruct judges to prefer the Constitution tojudicial precedentsrepugnant thereto. And when a precedent is demonstrably erroneous, as Roe and Casey are, it may not even remain relevant for future adjudications on the underlying matter.

AG Fitchs brief is also distinguished by the inclusion of a subsection about recent advances in embryology and prenatal science that undermine Roes emphasis on viability as the gestational point before which a states interest in prenatal life is not strong enough to warrant an abortion ban. She even noted that the U.S. finds itself in the company of China and North Korea as some of the only countries that permit elective abortions after 20 weeks gestation. Other legal advocates might have shied away from such a bold line, preferring to make that pointed comparison in an op-ed and not a legal brief. But pro-lifers should be grateful that the justices on the high court will now see that stark and bloody reality laid out so clearly.

The Dobbs case, once it reaches the marble palace, will be a moment of truth. For pro-lifers who want nothing more than to put an end to this nations horrific five-decade-old experiment in state-sanctioned prenatal infanticide, it is time to begin praying. In the interim, Attorney General Fitch has gotten us off to a fine start.

Josh Hammer isNewsweekopinion editor, a research fellow at the Edmund Burke Foundation, and a contributing editor of Anchoring Truths.

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Mississippi Asks SCOTUS to Overturn Roe | Josh Hammer - First Things

Embryology

First Lady moves to transform healthcare – The Herald

The Herald

Tendai Rupapa-Senior Reporter

ZIMBABWE has, courtesy of First Lady Auxillia Mnangagwas partnership with Merck Foundation, provided more than 100 scholarships to Zimbabwean doctors in many critical specialties and under-served disciplines as part of a drive to transform healthcare quality and allow equitable access for all.

This is the first time since Independence in 1980 that a First Lady has led from the front and made interventions to ensure the nation accesses quality healthcare facilities.

Amai Mnangagwa, an ambassador for Merck More than a Mother, yesterday co-chaired Merck Foundations virtual annual summit with the organisations chief executive Dr Rasha Kelej.

She is also the countrys Health ambassador.

Areas covered by the scholarships, the First Lady said, included Fertility and Embryology, Oncology, Diabetes, Cardiovascular, Endocrinology, Sexual and Reproductive Medicine, Respiratory, Acute Medicines, Clinical Microbiology and infectious diseases.

Through the said scholarships, United Bulawayo Hospitals (UBH) now boasts a facility offering services to infertility patients.

Journalists have also benefited from the partnership and got an opportunity to sharpen their skills in reporting sensitive issues around infertility which are often stigmatised.

Yesterdays summit discussed capacity-building and development programmes aimed at transforming the landscape of patient care and make a history in Zimbabwe.

Id like to welcome all of you our doctors, the future healthcare experts who have either already graduated or undergoing or will join soon Merck Foundation scholarships of specialty training in critical and under-served specialities.

And to also meet the winners of all Merck Foundation Media Recognition Awards who are our health and social community champions to break infertility stigma and raise awareness about other health and social issues such as girl education and the ongoing coronavirus. I am proud of each one of you, keep up the good work, she said.

The First Lady said her partnership with Merck Foundation helped to reshape the public healthcare sector in Zimbabwe through training and mentorship for media partners to improve their role in effective community awareness.

In this difficult time of the third wave of coronavirus, she said it was critical to discuss the right strategy to address the global crisis and benefit from members training experience and many success stories.

Ladies and gentlemen; especially during the Covid-19 global crisis and lockdown, we are interested more than ever in building healthcare capacity and training our local doctors who are our first line defence and the heroes of our coronavirus battle.

We were also interested more than ever to advance our media capacity through health training and mentorship programmes and awards to improve the awareness about Covid-19 and how to stay safe and healthy during our day to day life, she said.

The First Lady said more than nine doctors had either graduated or enrolled in a Fertility and Embryology Training Programme in India, while over 20 doctors from different provinces in Zimbabwe were either undergoing or had been shortlisted for online one-year diploma in Sexual and Reproductive Medicines from South Wales, UK or Two-year Masters Degree in the Biotechnology of Human Assisted Reproduction and Embryology Valencia University, Spain.

Together with Ministry of Health we will follow up to ensure they are making a good use of this great opportunity so that they can help women in general and infertile couples in particular, across the country. Also, we are transforming the diabetes care in our country. More than 55 scholarships of one-year diploma, two-year master degree or master course have been provided to our doctors in the field of diabetes care.

Furthermore, together we enrolled five doctors to One-Year Online Post Graduate Diploma in Endocrinology and six doctors in one-year Preventive Cardiovascular Medicines Diploma from University of South Wales. Moreover, one doctor has been enrolled to One Year Fellowship in Surgical Oncology, in India, and will start as soon as the travel restrictions are lifted.

As the Merck more than a Mother ambassador, the First Lady said she would work in collaboration with various ministries to sensitise communities and rural areas to break the stigma around infertile women and to empower them through access to information, education, health and change of mindset.

She emphasised that the media has an important role to play in raising awareness to creating a culture shift to break infertility stigma.

We also organised Merck Foundation Health Media Training for journalists to educate them on how to be the voice of the voiceless and raise awareness on sensitive issues like breaking infertility stigma, she said.

Co-chairing the summit with Amai Mnangagwa, Senator Dr Kelej said their joint programmes sought to transform the patient care landscape in Zimbabwe through building healthcare capacity and raising awareness about breaking infertility stigma and support girl education.

By building professional healthcare capacity, we have been able to transform the landscape of patient care in Zimbabwe. This is a huge achievement.

I am happy to meet (virtually) our alumni and discuss their impact on improving the quality of healthcare in the country after receiving specialised medical scholarships provided by Merck Foundation.

Moreover, I am equally excited to meet the winners of the Merck Foundation Media Recognition Awards and to discuss with them the significant role they have been playing to break the stigma around infertility, empowering girls and women through education, and raising awareness about coronavirus, Dr Kelej said.

She said through her foundations partnership with Amai Mnangagwa, they had been able to reshape the landscape of Zimbabwes healthcare sector and empower healthcare providers and motivate them to provide better care to people, especially during this difficult time of Covid-19.

Moreover, together with Zimbabwe First Lady, Merck Foundation has introduced 6 important Awards for Media, Fashion, Film, and Music fraternity, she said.

Alumni from Merck Foundations initiatives also shared with the meeting their gratitude and how they had benefited from the First Ladys partnership with Merck Foundation.

Gynaecologist Dr Harrison Rambanepasi expressed gratitude for the opportunity he got to train in fertility and other associated fields.

The training was in India for three months.

I have also enrolled for a diploma in sexual and reproductive medicine with University of South Wales. Its an online one year course fully funded by the Merck Foundation.

There is an option to do a Masters degree. The training helps to enhance ones understanding of infertility issues and puts you in a better place to evaluate and treat patients having infertility problems, he said.

Dr Rambanepasi said following the training, he received, he had started seeing infertility patients at United Bulawayo Hospitals.

We evaluate them to try to find out what the cause of their infertility is. Before this scholarship training, it would have been impossible to try and start an infertility clinic at UBH. The challenge we have is that most of our patients cannot afford the various tests that are required as part of evaluation of infertile couples.

Unfortunately, Government hospitals are not doing most of the tests required so patients have to go to private laboratories and the costs there are prohibitive, he said.

Another beneficiary, Dr Mugove Madzivire, an obstetrician and gynaecologist who also lectures at the University of Zimbabwe (UZ), expressed gratitude and said he was already using the wealth of experience he gained in his work and teachings.

I have acquired a lot through my training in intra and IVF through the Merck sponsorship. I acquired a host of diagnostic skills. I acquired proficiency in intravenous scanning. I also benefited through therapeutic skills and I was then able to do wall-side retrievals and prescribe IVF cycles, he said.

Dr Madzivire said when he came back from the Merck sponsored fellowship, he was able to increase his service to patients and impart the knowledge to his students.

He thanked the First Lady for the opportunity which he said would benefit the nation.

The Heralds Features, Health and Society Editor, Roselyn Sachiti, said the training she received from Merck Foundation had helped broaden her horizons and application as a journalist.

The training from Merck Foundation, in partnership with First Lady Amai Mnangagwa, has helped me broaden my horizons and knowledge around infertility. I now have a better understanding of and appreciation of how infertility affects both men and women equally, the challenges they face, she said.

Sachiti paid tribute to Amai Mnangagwa for the work she was doing in raising awareness on infertility and the support she was giving women and couples faced with infertility.

Through her work, Amai Mnangagwa has reached out to affected couples. As the media we will continue to support her work through the articles we write to raise awareness on infertility. I also thank Dr Kelej for the work she is doing in Africa, not just training the media, giving out awards, but supporting doctors with training in underserved disciplines, she said.

Another winning journalist, Tashinga Masawi said infertility was one of the most challenging things one could go through in life.

The random comments and statements that people find so easy to throw around when they assume one should be with a child cause so much pain and discomfort to many who are struggling with infertility issues. One of the things that makes this battle even more difficult is the culture of secrecy around the issue and the belief that infertility is a womans problem. This is why initiatives by the First Lady and the Merck Foundation are important and effective, she said.

The efforts that our First Lady Amai Mnangagwa have put in addressing sensitive issues are indeed timely and without a doubt something our generation needs. I am grateful to our First Lady Amai Mnangagwa, Dr Rasha Kelej and the Merck Foundation for giving the African woman a voice.

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First Lady moves to transform healthcare - The Herald

Genetics

Around the World in 50000 Years: The Genetics of Race – The MIT Press Reader

To fully understand race and genetics, we have to consider where we came from and how we got here.

By: Stanley Fields and Mark Johnston

The Food and Drug Administration (FDA) approved BiDil, a drug for the treatment of heart failure in self-identified black patients. . . . Todays approval of a drug to treat severe heart failure in [a] self-identified black population is a striking example of how a treatment can benefit some patients even if it does not help all patients, said Dr. Robert Temple, FDA Associate Director of Medical Policy. The information presented to the FDA clearly showed that blacks suffering from heart failure will now have an additional safe and effective option for treating their condition. In the future, we hope to discover characteristics that identify people of any race who might be helped by BiDil.

FDA News, June 23, 2005

Top-seeded Jimmy Connors stepped onto Centre Court at Wimbledon for the 1975 mens final having declared that it would be just another day at the office. Ranked number one in the world, the 22-year-old defending Wimbledon champion had not dropped a single set en route to the final. The brash left-hander was the overwhelming favorite against the other finalist, sixth-seeded Arthur Ashe. Connors was famed for his explosive outbursts on the court; the 31-year-old Ashe calmly closed his eyes and meditated between games.

The three previous times these rivals had met, Connors had prevailed decisively, and commentators at Wimbledon that day hoped only that Ashe would not be embarrassed on the court. To their surprise, Ashe began the match in dazzling fashion. Instead of trying to out-hit the hard-slugging Connors, Ashe brilliantly executed a game plan of slices, chip returns, lobs, and other change-of-pace shots, to dominate the first two sets 61.

Connors, never a quitter, fought back to win the third set 75, keeping alive his hopes for a stirring comeback. He started out the fourth set strongly to gain a 30 advantage and was but a point away from 41, but Ashe, resolutely sticking to his game plan even when on the defensive, rallied to win the set and match and become the first and still the only African American to win the Mens Championship of the All England Club. It was the only time he would ever defeat Connors.

Four years after his triumph at Wimbledon, while participating in a tennis clinic, Ashe suffered a heart attack that necessitated quadruple bypass surgery four months later. It forced his retirement from tennis soon after, and his continuing heart problems led to more surgery in 1983.

Ashe never forgot his childhood in segregated Richmond, Virginia, where he had been excluded from whites-only tennis tournaments. Or the Davis Cup match in 1965 between the United States and Mexico that had to be moved from the private Dallas Country Club to a public facility because club members objected to his presence on their courts. He once said that if he was remembered only as a tennis player he would have been a failure. But he is remembered as so much more.

Few issues are as contentious in American society as race. As stellar a citizen of court and country as Ashe was, he was at one time called an Uncle Tom for appearing to legitimize the South African government. At other times he was criticized for not doing enough to further the careers of young black tennis players. Given the history of race in America, the relationship between race and genetics is a landmine for researchers who attempt to study the subject. A host of issues the very definition of race, the dispute over whether race is a valid categorization of people, the question of which traits might have a race-specific genetic basis, the utility of using racial identity to assist in finding disease genes, and the value of targeting drugs to certain racial groups provoke intense feelings and heated debate. Because humans seem to have a need to define and differentiate themselves, and because many Americans believe race is so evident a category since it seems to be plainly visible in front of their eyes, the use of race as a classifier of people pervades much of our collective daily existence.

Given the history of race in America, the relationship between race and genetics is a landmine for researchers who attempt to study the subject.

In tackling the issue of genetics and race, we are painfully aware that the widespread racial discrimination in Americas history was often aided by ostensibly objective geneticists claiming to draw on the latest scientific orthodoxy. Efforts from the 17th century onward to classify humans into major groupings perpetuated the notion that the classifiers invariably white men belonged to a nobler group than did members of other races. This kind of eugenic thinking culminated in the United States with Jim Crow laws such as the one-drop rule, as formulated in the Racial Integrity Act, passed by the Virginia legislature in 1924: It shall hereafter be unlawful for any white person in this State to marry any save a white person, or a person with no other admixture of blood than white and American Indian. For the purpose of this act, the term white person shall apply only to the person who has no trace whatsoever of any blood other than Caucasian (italics added). This law stood until it was declared unconstitutional by the U.S. Supreme Court in 1967.

It would be most unfortunate if recent findings from the Human Genome Project and our increasing ability to characterize our personal DNA codes led to a revival of genetic determinism based on racial groupings. Particularly misplaced is the notion that if a genetic association between a disease and a racial group is found, then all members of that group, including individuals who dont carry the gene variant disposing them to the disease, share the same risk of the disease, especially when the group at risk is not even clearly defined. Even worse is the view that some studies can be construed to support the presumption of a racially determined genetic basis for traits such as athletic ability, intelligence, or criminality, without any good evidence for such a claim.

There is no question that various communities in our society today face enormous disparities in their access to health care, education and employment, and in their diets and levels of stress. Overwhelmingly these disparities boil down not to genetic differences but to economic disadvantages: health is wealth. Yet even when the statisticians account for economic inequality in access to health care and treatments, certain diseases have a much greater prevalence or significantly more severe outcomes in certain populations traditionally viewed as races. Why is this the case?

To understand race and genetics, we have to consider where we came from and how we got here. The fossil evidence suggests that anatomically modern humans, those with physical characteristics not too different from our own, emerged in Africa about 200,000 years ago an exceedingly brief period in evolutionary time. These humans were part of the lineage of hominids, the family of great apes that comprises humans, chimpanzees, gorillas, and orangutans. The branch of that family that leads to humans split off about six million years ago from the last ancestor we shared with our closest relatives, the chimpanzees; the chimpanzees DNA sequence is about 99 percent identical to ours. The human evolutionary tree indicates that humans did not evolve from current chimpanzees (or monkeys or gorillas or apes). Rather, both we and chimpanzees evolved from an ancestor no longer in existence who lived about six million years ago and whose various descendants would eventually give rise to two lineages, one that became us, and one that led to todays chimpanzees.

Anatomically modern humans first appeared in sub-Saharan Africa, and groups of them ventured out of Africa around 50,000 years ago, spreading throughout the Eurasian landmass the Mediterranean coast, Europe, Russia, and central Asia and into Australia. They got to Siberia by 30,000 years ago, and then moved across the Bering Strait and into the Americas about 15,000 years ago, along the way inventing paper in China, mathematics in the Middle East, and country music in the United States. The key point to remember here is that humans spent about 150,000 years in Africa before they colonized the rest of the globe.

Upon their arrival in Eurasia, these early humans likely met the Neanderthals, an abundant hominid species that inhabited Europe and western Asia from about 400,000 to 30,000 years ago. Neanderthals and ancient humans last shared a common ancestor about 500,000 years ago, long before humans walked out of Africa. There is evidence that the globetrotting humans met their Neanderthal cousins in several places, but a comparison of our DNA to theirs suggests that the two groups never got to be very intimate.

Why did it take so long for early humans to venture out of Africa to enjoy the abundance of the rest of the world? It was around the time of the initial migrations out of Africa that humans acquired more sophisticated tools, ornaments, and weapons, even indulging in abstract art, all activities that were evidence of their increased intelligence. This greater brain capacity correlates with a major increase in the population during that time, which may have made them more able to strike out to find new places in the world.

The implications of this model of human evolution are profound. It means that all six-plus billion of us on earth today descended from a small number of people, probably no more than 10,000, who lived in Africa around 50,000 years ago. The migrants who left Africa for points distant were a small subset of all the individuals then alive in Africa, a fact that has far-reaching consequences for human genetics.

If we look at the personal DNA codes of several present-day people to see how many DNA sequence differences we find in them that is, in how many positions in the genome one person has, say, an A on one strand, and another person has a G we learn that the number of these variants is significantly greater among Africans than it is among people in other geographic groups. Furthermore, most of the variation seen in populations outside of Africa is also present in the people who live in Africa. For example, if we find that the base at a particular position in the genomes of some Asian people is usually a C and occasionally a T, then we typically find among the African population both the C and the T (and maybe a G as well) at that position. This is because the emigrants brought with them only a sampling of the genetic diversity in the population they left behind. In this case only people with C and T at the position in question emigrated; people with a G at that position stayed behind. Some of the variation reached locations around the globe, but all of it was left behind in the people who stayed back to hold down the fort in Africa. Of course, all humans those living in Africa as well as those who populated other lands continued to evolve.

The consequence of a slowly spreading human population is Race is space, as Rick Kittles of Howard University and Kenneth Weiss of Pennsylvania State University put it. A new DNA sequence variation that arises in a single individual may spread geographically, but it will move slowly because human generations are long, about 20 years, and in our evolutionary history prior to the advent of internet-based matchmakers we tended to mate only with our neighbors. So if a particular gene variant is found in populations around the globe, it is likely to be ancient, and was probably present 50,000 years ago, when our ancestors hiked out of Africa.

The geographic distance between two populations, the greater their genetic differences.

Conversely, rare variants tend to be much more recent, meaning that they have arisen within the last 50,000 years, and tend to be found only in individuals living in particular regions. In other words, gene variants have been accumulating in people living in Africa for about 200,000 years, much longer than the 50,000 years they have had to accumulate in the population residing on the rest of the planet.

The geographic clustering of early humans did not generate discrete racial groups. Instead, the genetic variation in humans spread in gradients, with the frequency of one particular form of a gene increasing in some directions, decreasing in others. Thus the greater the geographic distance between two populations, the greater their genetic differences: The development of different races is simply due to the space separating them that leads to two genetically distinct populations.

So in light of this history, what is race? There is no generally and consistently accepted definition. Some define a racial group according to physical features such as skin color and hair texture, which reflect a shared ancestry. But others see race as purely an invention, often of white males, to justify cultural practices. Regardless of the conflicting definitions, we think its fair to ask whether a biological basis for the concept of race exists.

The key point to bear in mind when discussing possible biological groupings of humans is that no matter what genes you examine and no matter how you define your population groups, about 85 to 95 percent of all the genetic variation you observe in our personal DNA codes is found within all of the population groups; the small balance of variation is all that exists between groups. Imagine that we took random groups of citizens from Cameroon, China, Canada, and the Czech Republic and sequenced all six billion base-pairs of their personal DNA codes (something well be able to do soon). Wed find a lot of differences within each of them six million or so. But the differences that wed find among those from Cameroon are very largely the same ones wed find in common among people belonging to the other three groups. Could we use these sequence data to define a gene or genes for being Cameroonian, or Chinese, or Canadian, or Czech? Of course not! No such genes exist. We are all way too similar in our genetic makeup for that to be possible. Nonetheless, if you compared the variation present in say, the Cameroonian, to the variation present in all the worlds population groups, you would probably find enough specific differences to be able to place that individual quite close to Cameroon.

What about the 5 to 15 percent of the variations that have been found to be typical of one human group or another? Do some of these affect skin color or hair texture or other differences in appearance? Of course they do. All of our physical traits are ultimately determined by our genes. We humans are so anthropocentric that when we look closely at our fellow beings, we notice the tiny differences in the shape of an eye, the slope of a nose, the thickness of a lip. But climb only a hundred feet up a hill and you will have a hard time distinguishing those characteristics. From that perspective we are all nearly identical: the same size, the same shape, with the same number of arms and legs, the same locations for eyes and ears, the same everything else. Thus, classifying individuals into a few groups based on minor differences in appearance and then using those groupings to make inferences about the genetic basis of complex social behaviors is to ignore the huge amount of genetic variation everyone in the world shares.

How do the worldwide patterns of genetic variation that exist affect our ability to identify disease genes? Clearly, some diseases are more prevalent in individuals in one group than in those of another. The prevalence of Tay-Sachs disease is higher in Ashkenazi Jews than in other groups; sickle-cell anemia is most frequent in Africans; phenylketonuria is essentially absent in Africans. We do not sample Lapps to study Tay-Sachs Disease, Norwegians for sickle cell anemia, or Nigerians for PKU, write Kittles and Weiss.

So heres the heart of the race/genetic relationship. Unless and until widespread intermarriage among all humans leads to one homogeneous population, we can more or less divide most of the worldwide pattern of local genetic variation into a few large general, and quite rough, groupings: Africans, Europeans and Middle Easterners, east Asians, and Native Americans. (This oversimplified scheme leaves out a host of smaller subpopulations.) These groupings which you can call races if you want contain that small percentage of rare DNA sequence variation (5 to 15 percent) that produces the diversity in the global police lineup.

More important, these rare variants contribute significantly to differences in peoples risk for certain diseases. For example, African American women often develop breast cancer at a younger age than white women who get the disease, and have nearly double the rate of an aggressive form that is resistant to many treatments. Physicians who treat breast cancer patients are beginning to look to Africa to explain some of these differences, hoping to find genetic variants there that may predispose black women to this virulent form of the disease. Another example: Genetic variants among Ashkenazi Jews, a small subgroup of all humans with European origins, lead to an incidence of Tay-Sachs disease 100 times greater than is found in other populations. But these differences in our DNA dont reflect some kind of inferior genetics, any more than the much higher rate of PKU in people with lighter skin than in people with darker skin says anything about racial fitness.

Using minor differences in appearance to make inferences about the genetic basis of complex social behaviors is to ignore the huge amount of genetic variation everyone in the world shares.

What about BiDil and the targeting of pharmaceuticals to racial groups? This drug is actually a combination of two drugs, hydralazine and isosorbide dinitrate, that had been available for decades and are sold in generic form. Earlier studies of the drug combination had not produced evidence convincing enough to justify its approval, but an analysis of subgroups of patients a suspect form of data analysis because the question being tested is stated after you have the answer revealed a benefit of the drug for blacks. This finding inspired a new trial called the African-American Heart Failure Trial, carried out only on self-identified African Americans. The results were stunning: BiDil, used along with conventional therapies, led to a 43 percent increase in the rate of survival of heart failure patients compared to those in the study treated only with conventional therapies.

Surely you can appreciate that BiDil does not target the products of genes that influence skin color or hair texture or facial features. Rather, some combination of differences in hypertension, salt sensitivity, and other physiological properties in this self-identified population might differ from the rest of the population such that this drug is especially effective for them. As of this writing, the specific differences in our personal DNA codes that are the basis for this difference arent known, but they probably will be soon. At that point, regardless of your skin color or what ethnic group you associate yourself with, if you have the BiDil-sensitive variations in your DNA code, the drug will likely help you. And however dark your skin, or however closely you identify yourself with others with dark skin, if you dont have those particular DNA sequence variations in your DNA code you wont be helped by BiDil.

We dont know whether BiDil would have helped Arthur Ashe after his heart disease became apparent. It likely wouldnt have mattered anyway. Five years after his second heart surgery, Ashe was hospitalized for toxoplasmosis, a parasitic infection, and learned that he had AIDS, apparently caused by the presence of the Human Immunodeficiency Virus (HIV) in blood he received during his surgery in 1983. Ashe held a press conference in April 1992 to announce that he had the disease. A year later he was dead of AIDS-related pneumonia.

Will the knowledge of the specific DNA sequence variants each of us carry in our personal DNA codes which affect disease susceptibility, drug efficacy, and many more things that are important to us end the racism in America that Ashe worked hard to overcome? Will health disparities disappear because we can determine the sequence of DNA and therefore no longer need to classify individuals on the basis of appearance to take advantage of their genetic differences? Likely not. We know all too well that those societal outcomes wont be realized because of new genetic knowledge. But we can hope that genetic knowledge wont make the problems any worse.

Someday, perhaps, well come to appreciate that even though the 0.1 percent difference in the DNA between any two of us might mean the difference between being or not being disposed to get a particular disease, the 99.9 percent similarity means that were all close relatives: We are all descended from the same ancestors who came out of Africa not so long ago.

Stanley Fields is Professor of Genome Sciences and Medicine at the University of Washington and a Howard Hughes Medical Institute Investigator. Mark Johnston is Professor and Chair of the Department of Biochemistry and Molecular Genetics at the University of Colorado School of Medicine and Editor-in-Chief of the journal Genetics. Fields and Johnston are the authors of Genetic Twists of Fate.

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Genetics

Genetic Testing Gaining Popularity In Healthcare: All You Need To Know About It – TheHealthSite

If the term 'genetic testing' is something new to you, you're not alone. Not many people in India are aware of this advanced technology that can help determine a person's susceptibility to various diseases, as well as prevent or delay their onset with personalised healthcare. Because genetic testing had been largely used only for the specific diagnosis/detection purpose and neonatal healthcare in India, people were unaware of the vast benefits of genetic testing. Over the last few years, however, personalized genetic testing has gained popularity for the prevention of diseases like cancer, tuberculosis, etc. The increasing awareness among the population regarding early diagnosis coupled with rising expenditure on preventive measures has further fuelled the demand for genetic testing in the market, specifically in the areas of personalized healthcare and screening for predisposition of various diseases.

Let's learn more about genetic testing, including its uses, benefits, and demand in India, from Amol Naikawadi, Joint Managing Director, Indus Health Plus Pvt Ltd.

Indus Health Plus launched its Genetic Testing Services in India in December 2018. Since its launch, the company said, it has observed that the demand for such packages is not only in metros, but tier II and III cities are also equally responding positively to this trend.

Below are excerpts from an exclusive email interaction with Naikawadi -

The entire structure and functioning of the body are dependent on our genes. For example, genes, a short section of DNA, contain instructions that instruct cells to make molecules called proteins. Different proteins carry out most of the functions inside human body. For example, various hormones, enzymes, antibodies, etc. all are proteins whose synthesis instructions are encoded in the genes.

Genes also carry information that determines our hair colour, height, eye colour, etc. With genes playing such an important role in the overall crux of our being, they also can help prevent diseases. How - we might ask? The answer is through genetic testing.

A technologically advanced prevention tool that can personalise an individual's health, thereby reducing the costs associated with non-communicable diseases (NCDs). It identifies the changes in one's genes, proteins, chromosomes, thus determining a person's susceptibility to genetic disorders.

There are different types of genetic tests available for various concerns. Such as:

These tests help us understand the genetic variations related to our health traits, the kind of food we're sensitive to, our body's metabolism rate, the medicine we should be consuming, etc. We can also receive information on the hereditary health risks, fitness and skincare routine we should ideally follow.

In pregnant women between the 10th and 12th week of pregnancy, genetic testing ensures if the foetus is developing well and is healthy. Newborn screening shows whether the toddler has any metabolic or congenital abnormality. Generally, the procedure and results are better understood under a geneticist's guidance.

The two predominant kinds of the test are clinical genetic testing and personal genomics testing.

Clinical Genetic Testing It is the laboratory analysis of the DNA or RNA to pre-empt the possibility of any disease. The purpose of this test is to anticipate an illness before the symptoms even arise and get a definite diagnosis. An individual who has symptoms of a genetic disorder might undergo a diagnostic test for precise detection.

Personal Genomic Testing - This kind plays a vital role in the field of personalised and preventive healthcare. It can help anticipate an individual's susceptibility to a disease, the kind of drugs and the type of treatment, best suited to their health.

Thus, the test allows one to receive an analysis of their DNA:

With work and academic pressure piling over, many don't bother keeping their health a top priority. People spend hours sitting in front of their laptops working or binge-watching, thus leading a sedentary life. Multiple NCDs arise due to unhealthy eating, no exercise, substance (drugs, tobacco, and alcohol) abuse, etc. Thus, causing heart disorders, fatty liver, diabetes and many other health conditions. Exposure to environmental toxins, air pollution, have also increased incidence of asthma, cancer and other health conditions.

However, in most lifestyle diseases, we can avoid the risks by modifying our diet, adding a suitable fitness regime, taking necessary precautions, etc. NCDs cause severe trauma and out-of-pocket expenses for the family. An increased level of awareness and education about early detection and prevention can reduce them.

A personalised genetic test identifies biological markers present in an individual that may be associated with an increased risk for specific diseases, thus, reducing the likelihood of NCDs. It also allows doctors to treat the patient more effectively, and in most cases, the individual can live a long and healthy life.

In India, the majority don't have an idea about genetic testing. People mostly know the term famously in the context of DNA tests with relevance to paternity testing and forensic investigation.

Masses do not know the relevance of genetic testing in terms of health and fitness. Even the elite class, the educated section including clinicians, are not entirely aware of the potential benefits of genetic testing.

When an individual move to the interiors, people from rural areas have little to no information on genetic testing. And the reasons are evidently because of a lack of access to quality healthcare and limited diagnostic centres or hospitals there. The concept of genetic testing is a foreign entity in these areas.

Lack of awareness and acceptance both are bottlenecks in the implementation of genetic testing in routine healthcare. A few reasons for the absence of mass popularity of genetic testing are:

Certain genetic variants determine one's response to a specific type of exercise and how it affects their body. For example, people who have a specific variant in the Fat mass and obesity (FTO) gene that increases body weight are more likely to benefit from physical exercise. At the same time, some are genetically wired to feel fatigued and are best suited for light workouts.

Genetic variations also affect a person's food taste, likes and dislikes, food intolerances, etc. An excellent example of genetic controlled tasting ability is the presence of phenylthiocarbamide (PTC) in food like cauliflower, Brussel sprouts, wine, pepper, kale, etc. Based on one's genes, they can either find the element very bitter or tasteless. The single gene TAS2R38 is responsible for an individual's ability to taste PTC.

Gene variations are also partially responsible for metabolism rate, absorption of food, catabolism, storage, biosynthesis, and excretion.

Our genes determine whether we're allergic to gluten or are lactose intolerant. Overall, a genetic test gives a detailed understanding of the patient's genetic make-up, thus helping a nutritionist form a personalised diet plan.

Nutrigenetics: It is the study of how genes determine the effects nutrients have on the body and health. Response of the body to the food we eat is based on our nutrigenetic profile. This is because specific genes are associated with nutrient absorption and utilization, food intolerances and sensitivities, and nutritional requirements and deficiencies.

Sports Genomics Concept: It is a relatively new branch of genetics in the discipline. Sports genomics is the study of the genetic make-up or architecture that contribute to an athlete's performance. The same principle is applicable to every individual who plan to personalize their fitness routine as genes influences our response to many exercise-related traits.

As mentioned previously, genetic tests help us smartly eradicate guesswork and approach fitness in the best way. The reports make us conscious about our endurance to a workout plan. Based on this, experts might recommend either a high-intensity or a more extended training session.

India is slowly starting to look at genetic testing as an essential preventive healthcare tool. Many more diagnostic centres have begun entering this domain. Healthcare is evolving every day, and genetic testing will go a long way in revolutionising it.

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Genetics

The Genetic Architecture of Parkinsons Disease in Latino Populations – Technology Networks

An international research team led by Cleveland Clinic has presented the most comprehensive characterization of the underlying genetic basis for Parkinsons disease (PD) in Latinos to date, marking an important step towards more inclusive PD genetic research.

Parkinsons disease impacts all ethnic groups, but since genetic studies have largely been limited to individuals of European and East Asian ancestry, little is known about the genetic architecture of the disease in Latino populations, said Ignacio Mata, Ph.D., assistant staff in the Genomic Medicine Institute and lead author on the study. As we see incidence rates rise in nearly every global region, the importance of greater diversity in Parkinsons research cannot be overlooked.

In this study, published in Annals of Neurology, Dr. Mata and international collaborators performed the first ever genome-wide association study (GWAS) of Latino PD patients from South America. Their analysis relied on patient data from the worlds largest PD case-control cohort of Latinos, called the Latin American Research Consortium on the Genetics of Parkinsons Disease (LARGE-PD), which includes individuals from 35 institutions in 12 countries across Latin America and the Caribbean.

Notably, they demonstrated that SNCA, a gene previously linked to PD in European and East Asian populations, had genome-wide significance in the LARGE-PD cohort and a replication cohort, indicating its critical role in PD etiology in Latinos. In addition, they identified the novel gene NRROS as a biologically plausible PD risk gene, particularly in individuals from Peru, but indicated that further studies are needed to validate this finding.

The researchers then assessed the significance of PD variants previously identified in European and East Asian populations for the LARGE-PD cohort, and found a substantial overlap of PD genetic architecture between Europeans and Latinos. They also explored the relationship between PD risk and Latino population ancestry and pinpointed variants associated with African and Native American ancestries that may influence PD risk.

As we continue our work to gain comprehensive understanding of population-specific PD genetic architecture in Latino populations, inclusion of Latino PD patients from diverse ancestral backgrounds, such as those with significant Native American or African ancestries, is a necessity, Dr. Mata said. Parkinsons is a global disease, so it is crucial that genetic studies reflect the wide diversity of patients with the disease.

Reference:Sarihan EI, Prez-Palma E, Niestroj L-M, et al. Genome-wide analysis of copy number variation in Latin American Parkinson's disease patients. Mov. Disord. 2021;36(2):434-441. doi:10.1002/mds.28353

This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source.

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Genetics

Cornell study indicates hemp goes hot due to genetics, not weather or environment – Hemp Industry Daily

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Genetics

DNA Hoarders: Genetic Duplication Linked to the Origin and Evolution of Pine Trees and Their Relatives – SciTechDaily

New research shows genome duplication in the ancestor of modern gymnosperms, a group of seed plants that includes cypresses and pines, might have directly contributed to the origin of the group over 350 million years ago. Credit: Kristen Grace/Florida Museum of Natural History

Plants are DNA hoarders. Adhering to the maxim of never throwing anything out that might be useful later, they often duplicate their entire genome and hang on to the added genetic baggage. All those extra genes are then free to mutate and produce new physical traits, hastening the tempo of evolution.

A new study shows that such duplication events have been vitally important throughout the evolutionary history of gymnosperms, a diverse group of seed plants that includes pines, cypresses, sequoias, ginkgos, and cycads. Published on July 19, 2021, in Nature Plants, the research indicates that a genome duplication in the ancestor of modern gymnosperms might have directly contributed to the origin of the group over 350 million years ago. Subsequent duplications provided raw material for the evolution of innovative traits that enabled these plants to persist in dramatically changing ecosystems, laying the foundation for a recent resurgence over the last 20 million years.

This event at the start of their evolution created an opportunity for genes to evolve and create totally new functions that potentially helped gymnosperms transition to new habitats and aided in their ecological ascendance, said Gregory Stull, a recent doctoral graduate of the Florida Museum of Natural History and lead author of the study.

Some conifer and cycad species have highly restricted distributions and are at risk of going extinct due to climate change and habitat loss. These conifers, Araucaria goroensis, also known as the monkey puzzle tree, and Dacrydium araucarioides are unique to New Caledonia. Credit: Nicolas Anger

While having more than two sets of chromosomes a phenomenon called polyploidy is rare in animals, in plants it is commonplace. Most of the fruits and vegetables we eat, for example, are polyploids, often involving hybridization between two closely related species. Many plants, including wheat, peanuts, coffee, oats, and strawberries, benefit from having multiple divergent copies of DNA, which can lead to faster growth rates and an increase in size and weight.

Until now, however, its been unclear how polyploidy may have influenced the evolution of gymnosperms. Although they have some of the largest genomes in the plant kingdom, they have low chromosome numbers, which for decades prompted scientists to assume that polyploidy wasnt as prevalent or important in these plants.

Gymnosperm genetics are also complex. Their large genomes make them challenging to study, and much of their DNA consists of repeating sequences that dont code for anything.

Some gymnosperm traits, such as cone structure, color, shape and size, may have arisen as a result of multiple genome duplications. This is a female cone of the species Callitris pancheri. Credit: Nicolas Anger

What makes gymnosperm genomes complex is they seem to have a proclivity for accumulating lots of repetitive elements, said study co-author Douglas Soltis, Florida Museum curator and University of Florida distinguished professor. Things like ginkgos, cycads, pines and other conifers are loaded with all this repetitive stuff that has nothing to do with genome duplication.

However, a recent collaborative effort among plant biologists, including Soltis, to obtain massive numbers of genetic sequences from more than 1,000 plants has opened new doors for scientists attempting to piece together the long history of land plant evolution. Stull, now a postdoctoral researcher at the Chinese Academy of Sciences Kunming Institute of Botany, and his colleagues used a combination of these data and newly generated sequences to give gymnosperms another look.

By comparing the DNA of living gymnosperms, the researchers were able to peer back in time, uncovering evidence for multiple ancient genome duplication events that coincided with the origin of major groups.

Gymnosperms have undergone significant extinctions throughout their long history, making it difficult to decipher the exact nature of their relationships. But the genomes of all living gymnosperms share the signature of an ancient duplication in the distant past, more than 350 million years ago. More than 100 million years later, another duplication gave rise to the pine family, while a third led to the origin of podocarps, a group containing mostly trees and shrubs that today are primarily restricted to the Southern Hemisphere.

In each case, analyses revealed a strong link between duplicated DNA and the evolution of unique traits. While future studies are needed to determine exactly which traits arose due to polyploidy, possible candidates include the strange egglike roots of cycads that harbor nitrogen-fixing bacteria and the diverse cone structures found across modern conifers. Podocarp cones, for example, are highly modified and look deceptively like fruit, said Stull: Their cones are very fleshy, have various colors, and are dispersed by different animals.

Stull and his colleagues also wanted to know whether genome duplications influenced the rate at which new gymnosperm species evolved through time. But instead of a clear-cut pattern, they found a complex interplay of extinction and diversification amidst a backdrop of a significantly changing global climates.

Today, there are about 1,000 gymnosperm species, which may not seem like many when compared with the 300,000 or so species of flowering plants. But in their heyday, gymnosperms were much more diverse.

Gymnosperms were still thriving prior to the asteroid extinction event 66 million years ago, best known for the demise of dinosaurs. But the dramatic ecological changes brought about by the impact tipped the scales: After the dinosaurs disappeared, flowering plants quickly began outcompeting gymnosperm lineages, which suffered major bouts of extinction as a result. Some groups were snuffed out entirely, while others barely managed to survive to the present. The once-flourishing ginkgo family, for example, is today represented by a single living species.

But the results from this study indicate that at least some gymnosperm groups made a comeback starting around 20 million years ago, coinciding with Earths transition to a cooler, drier climate.

We see points in history where gymnosperms didnt just continue to decline, but they actually diversified in species numbers as well, which makes for a more dynamic picture of their evolutionary history, said co-author Pamela Soltis, Florida Museum curator and UF distinguished professor.

While some gymnosperms failed to cope with the dual specter of climate change and competition, others had an advantage in certain habitats due to the very traits that caused them to lose out in their ancient rivalry with flowering plants. Groups such as pines, spruces, firs and junipers got fresh starts.

In some respects, gymnosperms maybe arent that flexible, Pamela Soltis said. They kind of have to wait around until climate is more favorable in order for them to diversify.

In some environments, gymnosperms adapted to live at the extremes. In pine forests of southeastern North America, longleaf pines are adapted to frequent fires that incinerate their competition, and conifers dominate the boreal forests of the far north. But take away the fire or the cold, and flowering plants quickly start to encroach.

While gymnosperms are still in the process of diversifying, theyve been interrupted by human-made changes to the environment. Currently, more than 40% of gymnosperms are threatened by extinction due to the cumulative pressures of climate change and habitat loss. Future studies clarifying how their underlying genetics enabled them to persist to the present may give scientists a better framework for ensuring they survive well into the future.

Even though some conifer and cycad groups have diversified considerably over the past 20 million years, many species have highly restricted distributions and are at risk of extinction, Stull said. Efforts to reduce habitat loss are likely essential for conserving the many species currently threatened by extinction.

The researchers published their findings in Nature Plants.

Reference: Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms by Gregory W. Stull, Xiao-Jian Qu, Caroline Parins-Fukuchi, Ying-Ying Yang, Jun-Bo Yang, Zhi-Yun Yang, Yi Hu, Hong Ma, Pamela S. Soltis, Douglas E. Soltis, De-Zhu Li, Stephen A. Smith and Ting-Shuang Yi, 19 July 2021, Nature Plants.DOI: 10.1038/s41477-021-00964-4

Other co-authors of the study are Xiao-Jian Qu of Shandong Normal University; Caroline Parins-Fukuchi of the University of Chicago; Ying-Ying Yang, Jun-Bo Yang, Zhi-Yun Yang, De-Zhu Li and Ting-Shuang Yi of the Chinese Academy of Sciences; Yi Hu and Hong Ma of Pennsylvania State University; and Stephen Smith of the University of Michigan.

Funding for the research was provided by the Chinese Academy of Sciences, the National Natural Science Foundation of China, the Yunling International High-end Experts Program of Yunnan Province and the Natural Science Foundation of Shandong Province. Stull also received support from the CAS Presidents International Fellowship Initiative and the China Postdoctoral Science Foundations International Postdoctoral Exchange Program.

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DNA Hoarders: Genetic Duplication Linked to the Origin and Evolution of Pine Trees and Their Relatives - SciTechDaily

Genetics

Fulgent Genetics: A Buy If You Believe COVID Testing Is Here To Stay – Seeking Alpha

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