As a future social worker, I am fascinated that unborn humans are often left out of the rhetoric for equal and basic human rights.

The following statements are held to be true by all social workers who adhere to the National Association of Social Workers Code of Ethics:

Social workers strive to help meet the basic human needs of all people, and every human life has inherent dignity and worth.

Isn't the most basic, fundamental need the right to life?

Furthermore, the first principle of a widely accepted social work ethics guide states the social workers first priority is the protection of human life, which applies to all persons, both the life of a client and the lives of all others.

The science of embryology shows the unborn child is a distinct human life from the moment of fertilization. If the social worker recognizes that every human life has inherent worth and basic rights and has pledged to defend those rights, what is the social worker's responsibility to the unborn population?

One may respond by saying that social workers must respect the self-determination of their clients.

However, according to the NASW Ethical Standards, "Social workers may limit clients' rights to self-determination when . . . (their) actions pose a serious, foreseeable, and imminent risk to themselves or others."

What if ones actions are posing a death risk to the human in their womb?

When considering the defense of vulnerable populations, lets remember the unborn.

Originally posted here:
Letter to the Editor: Arguments for equal and human rights must include the unborn - Tulsa World

There is no dark side of moon | Former NASA scientist busts age-old myth through his animation

A research conducted by a team of scientists at Bristol University has found that animal embryos evolved before animals. Until now, the evolution of animals was studied by analyzing living animals and their relatives.

But now, the research team has found that fossilized embryos that resemble multicellular stages in the life cycle of single-celled relatives of animals, which indicates that animal embryos started evolving first.

During the study, researchers discovered these fossils from 609 million-year-old rocks in the Guizhou Province of South China. Scientists have named these fossils Caveasphaera, and they are just only about half a millimetre in diameter. X-ray analysis done on these fossils revealed that they were preserved all the way down to their component cells.

"X-Ray tomographic microscopy works like a medical CT scanner but allows us to see features that are less than a thousandth of a millimetre in size. We were able to sort the fossils into growth stages, reconstructing the embryology of Caveasphaera," said Kelly Vargas, a researcher at the University of Bristol's School of Earth Sciences in a recent statement.

Zongjun Yin, from Nanjing Institute of Geology and Palaeontology in China, who is the co-author of the study suggested that Caveasphaera sorted its cells during embryo development in just the same way as living animals that include human beings. However, he made it clear that there is no evidence that these embryos developed into complex organs.

"Caveasphaera had a life cycle like the close living relatives of animals, which alternate between single-celled and multicellular stages. However, Caveasphaera goes one step further, reorganizing those cells during embryology," said John Cunningham, co-author of the study.

Few months back, a study conducted by a team of experts at the University of Queensland and Neel Institute had solved the billion-dollar 'chicken or egg' paradox. After using various theories of quantum physics, researchers found that both the chicken and egg can come first. However, another study conducted in 2014 argued that chicken came first, as proteins found in the body of chicken are necessary to form an egg.

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Animals embryos evolved before animals, study reveals - International Business Times, Singapore Edition

In an attempt to encourage a work and life balance and close its embarrassing gender pay gap, which reaches to 50,6 per cent, Goldman Sachs launched its new benefit scheme for its employees earlier this montha fund of $20,000 (15,400) to cover the costs of extracting or purchasing donated eggs for prospect parents.

This is not the first time a company announces a scheme of that nature. In 2014, tech-titans Apple and Facebook made headlines when they announced that they would include the option of egg freezing among their work benefits. Goldmans Pathways to parenthood project also includes delivering mothers breast milk to their children should they have to be away for work, and offers emergency nannies to look after unwell children.

While the efforts of a company of monstrous power to close gender pay gaps should not be dismissed, the reality is that it wont solve mothers problems and maintain a work and life balance. Rather, it will only increase their time spent at work by preventing women from being there for their families or even being present to in order to create one.

Egg freezing is a method of fertility preservation. Some women wish to freeze their eggs for medical reasons, such as cancer or any other illness that may trigger early menopause (in that case the process of egg freezing can be funded by NHS). Alternatively, other women go for social egg freezing, referring to women who wish to conceive at an older age due to career or high-risk career jobs (such as working in the army) or women who have yet to start hormone therapy when wishing to go through a sex change.

The process overall lasts 12 to 40 days, beginning with the womans circle, explained Suvir Venkataraman, the general manager at Harley Street Fertility Clinic in London. The ovaries are hyperstimulated with hormone injections in order to produce more than a single egg (which is usually produced in one menstrual circle). The eggs are then retrieved with a needle via a low-risk surgical procedure, individually fast-frozen via a method called vitrification, and placed in liquid nitrogen until needed. The eggs can usually be stored for up to ten years.

The treatment costs 3,500 but the medicine can cost from 600 to 1,800 depending on the patient. Overall were issuing a cost of 4,000 to 5,500 per circle, says Venkataraman. On top of the costs, you will need to undergo the procedure to fertilise the eggs (called ICSI) and factor in the potential of more circles needed in order to bank 10 to 20 eggs for a successful outcome, as only a small percentage of eggs are mature and capable of being fertilised. The success rate? In the past, the survival rate of frozen eggs was 30 per cent now its 90 per cent, shares Venkataraman.

Its hard to give a definite answer, however, as only 2,000 babies have been born worldwide from frozen eggs, 700 of them in the UK, according to the Human Fertilisation and Embryology Authority (HFEA). In 2017, only 19 per cent of IVF treatments using the patients own frozen eggs were successful. Furthermore, regardless of the condition of the fertile eggs themselves, older patients are at an increased risk for miscarriages and pregnancy-related complications.

Freezing fresh embryos (either from a donor or the patients partner), on the other hand, has a higher success rate, as embryos are not affected by the length of time they are frozen for. The process has helped prospect parents, and Hannah Selinger was one of the patients who had frozen her eggs, too. Sellinger spent $17,000 and claims that she regretted the whole process. She conceived naturally and, sardonically, during her pregnancy had found out that her eggs were destroyed. The reason was a lapse in communication, as she didnt receive the egg-rent reminders due to her moving to a new place.

Discussing Goldman Sachss scheme, Sellinger said that despite her experience she isnt against egg freezing, and that she believes the problem lies elsewhere. I think the real problem is to care about mothers, make sure that that mothers take six months to a year off, and that should be the case for paternity leave, too. It would be wiser for my government to move into that direction rather than ban abortions, I am only able to have children cause my husband makes enough money from me to do what I do.

While Venkataraman claims, Its really nice that we can help someone, because it means that theyll do as they please. Because we all live longer, our quality of life is better, we are able to stretch our biological clock and egg freezing allows women to do that with fertility as well. Its a great option but I dont think the socio-political system should force someone to do it. If you wish to freeze your eggs, feel free to do it. But dont do it because your company told you to, because your company wont care about youit will care about the money youre making.

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Egg freezing has become standard practice for big companies, but what are the pros and cons? - Screen Shot

25 November 2019

We are currently experiencing powerful digital, artificial intelligence, genomic science, epigenetics and human reproductive revolutions. These will increasingly blur the lines between the physical, digital and biological spheres.

However, as these technological advances create immense responsibilities, new national and international laws, policies and safeguards will become increasingly necessary.

As more people embrace the transformational impact of these technological revolutions and calculate the economic benefits, I predict that we will see new trends resulting in fewer natural conceptions, more genetically planned parenthood and increased demand for fertility treatment. This is good news for the fertility sector.

DNA (genetic) sequencingnow costs a few hundred pounds per genome, making its integration into the mainstream possible. Interpretation costs are additional, but seem likely to fall. It makes increasing economic sense to invest in genomic sequencing and possible remedies at the outset of fertility patient treatment.

Whole genome sequencing can currently help identify upwards of 40006000 diseases and this number is likely to grow. It is far cheaper than the cost of treating a sick child or adult and lost productivity in the workplace. It is likely to decrease the costs of institutionalised care and result in healthier people living better quality lives. This in turn is likely to increase GDP and lead to greater innovation and development of society as a whole.

Genome editing technologies are becoming more accurate, affordable and accessible to researchers, and could in future help switch genes on and off, target and study DNA sequences.

As genomic science and medicine becomes part of mainstream healthcare provision, I predict we will see a shift in perception towards genetically-planned parenthood to have a healthy child. This technology will help alleviate a biological lottery at birth, avoid condemning children and adults to preventable disease, pain and suffering and has the potential to improve opportunities in life. It could also help address fundamental societal issues of declining fertility levels, later-life conceptions and ageing populations.

At ground level, I expect to see changes to delivery of fertility treatment and patient care. The typical fertility patient treatment model is likely to evolve, incorporating three additional genomic steps at the outset: genomic sequencing, genetic counselling and genetic medicine (including genetic screening and genome editing).

Genomic technology, therefore, has great potential in preventing serious and deadly hereditary diseases and over time we will inevitably see greater pressure to push the boundaries of human genetic enhancements.

In the UK, the implantation of a genetically-altered embryo into a woman is currently prohibited under the Human Fertilisation and Embryology Act 1990, (as amended), excepting under certain conditions to prevent the transmission of serious mitochondrialdisease.

Taking account of these rapidly evolving sectors will require centralised state law and integrated policies. We would benefit from a dedicated Ministry for Fertility and Genomics, with a Minister providing a unified voice, agenda and future direction for the fertility sector as a whole. This would help develop a robust genomic and fertility policy and political strategy encompassing pre-conception through to birth and future genetic legacy.

Added to this, we should ensure the integration of specialist legal services to help protect fertility patients (and future born children) undertaking complex treatment and provide a truly multi-disciplinary medico-legal process.

We will also need informed and effective oversight of genomic science and medicine to protect standards and prevent abuse of this technology. Close oversight, accountability and transparency will be required, and regulation must strike a careful balance between respect for the individual and the interests of the state.

Law and policymakers must adopt caution in deploying these powerful technologies, and it will be important to see how countries across the globe meet the challenge. It will be vital to seek international consensus and build new international legal infrastructures to mitigate the risks and prevent rampant genomic and fertility tourism.

It will require engagement and commitment to help law and policymakers build effective legal and regulatory frameworks that will safely and successfully harness the enormous transformational power of genomic science and medicine in the fertility sector over the next 1020 years and beyond.

Success is there for the taking, but the stakes are very high and we overlook root and branch law and policy reform at our peril.

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Why we need root and branch fertility law reform - BioNews

November 25, 2019 (American Thinker) Today, largely due to government policy, doctors' offices have been transformed into a big governmentcontrolled business, and the American Academy of Family Physicians (AAFP), the leading body for family medicine in the United States, appears to prefer it that way. As older doctors like me leave the field, young idealistic physicians bypass family medicine; they are neither interested in working for a business nor motivated by a stifling code of political correctness that fails to recognize the dignity of every human being.

Over 50 years ago, purposeful ignorance of the definition of reproductive health and basic embryology initiated family medicine's decline. Embryology teaches that after an act of sexual intercourse, sperm and egg unite in the woman's fallopian tube, and a human life is created. Seven days later, that human implants in the woman's womb, and nine months later, the mother delivers her child. Ensuring that this process works as natural law intends is reproductive health care, just as ensuring that the heart pumps blood is cardiac health care. For family physicians, however, 1965 brought with it a new discovery about the beginning of life. No longer at fertilization, doctors now declared that human life began with uterine implantation. The new beginning was based not on Nobel Prizewinning medical research, but rather on a desire to cash in on the contraceptive pill, which occasionally prevents a human life from implanting in the womb. It was more lucrative to simply lie about the beginning of human life than to explain to patients the pill's abortifacient potential. Although appearing innocuous, this unscientific declaration demonstrated that family medicine was willing to sacrifice scientific excellence and medical ethics for consumerism. It set a precedent in which select people can claim something to be a medical fact and redefine it as such without any type of scientific analysis. And finally, it began the involvement of medicine in practices purposefully designed to prevent a human organ system from working properly the antithesis of health care.

This deception, led by physicians and amplified by governments, has led the world to believe that the reprophobic practices of contraception, abortion, and sterilization are the main elements of reproductive health care. The absurdity of this belief could best be compared to a government proposal in which physicians would prescribe alcohol as the main component of neurologic health care. Without ever entering into dialogue within the medical community about the pros and cons of enticing people to be more sexually active by unnaturally inhibiting the reproductive system, reprophobics became an essential element of health care. Although lucrative, the negative effects on the family of such treatment, including increased teen sexual activity, infidelity, and the death of family members, should be something family medicine physicians are particularly concerned about. But the AAFP is not, preferring to virtue-signal about the politically correct subject du jour while keeping the "family" in family medicine devoid of any real meaning.

So integral to family medicine has contraception becomethat not to prescribe it makes working as a physician difficult. Unable to afford the bureaucraticexpense of private practice, I have felt required on multiple occasions to proclaim religious beliefs as an excuse for my prescribing practices, while groveling before a prospective employer. In retrospect, this was always a weak argument, as it suggested that if not for myunscientific belief in a supernatural deity, I would prescribe reprophobics day and night. In reality, it is my medical beliefs that determine how I treat my patients; God did not order me to have them. They reflect extensive study of the family and sexuality, based on the natural law and its realistic consequences, which my wife and I do our best to put into practice.

Religious belief is just another term that progressives have cleverly co-opted to devalue convictions that are consistent with orthodox Christian values. Beliefs including that life begins at conception, homosexual "marriage" is wrong, and abortion is murder are dismissed as religious. Beliefs that life begins at some other time, gender is fluid, or abortion is great are not and therefore considered of higher importance.

My medical beliefs have helped to keep my family healthy; I want the same for my patients.

Control of prescription contraceptives makes physicians big-money players in the commercial side of sexual activity. The imperfection of contraception in preventing unwanted pregnanciesgives medicine another opportunity to profit, in this case through abortion procedures. The importance of these procedures in American medicine is clearly illustrated by aMay 2019 joint public statement that condemns state laws limiting abortion, complaining that they "inappropriately interfere with the patient-physician relationship" and "unnecessarily regulate the evidence-based practice of medicine." The underlying but unstated premise of the statement, promulgated by the AAFP and five other large medical associations, is that human lives are of different value, especially unborn family members. For unborn lives of higher value, the mother and child become patients, and it is (as it should be) the physician's responsibility to do his best to ensure a healthy delivery. For those of lesser value, the doctor is directed not only to walk away from the doctor-patient relationship, but, moreover, toenable child extermination.

Despite the public statement's grandiloquent description of family physicians as "informed by their years of medical education, training, experience, and the available evidence,"none of that is considered in the final decision about the value of an unborn family member. It is rather the often flawed analysis of a distraught teenage girl with a SpongeBob level of medical knowledge that leads to the life-or-death decision.

Without ever providing a rationale, AAFP directives strip the family physician of his role as true advocate for every pregnant mother and her child. Unable to defend its position on the basis of medical ethics, generally regarded as medicine's highest standard, the AAFP chooses rather to highlight abortion as evidence-based medicine. Voluminous evidence, most recently from the Planned Parenthood baby parts trafficking case, does at least support this claim, demonstrating the deadly effectiveness of this unethical and disturbing medical procedure. However, rather than interfere with the doctor-patient relationship as these organizations claim, recently passed laws mandate the establishment of such a relationship with a child whom doctors would otherwise have cruelly and unethically chosen to discard.

Since 1973, government has legalized a "religious" belief that unborn family members do not automatically deserve the right to life. At the time and continuing today, rather than stand up for the humanity of the unborn, something in which the physician has honored expertise, the AAFP produces condescending and illogical criticism of those voters who do. American medical organizations have allowed government to establish itself as a permanent intrusive member of the doctor-patient relationship and given credence to those who believe that some American lives have less value than others. Hidden behind terms like "reproductive health care," "evidence-based medicine," and "intrusion into the patient-doctor relationship" is our willingness as an organization to sacrifice human life for financial and political gain. When professions whose reputations are established based on Christlike ideals of helping the weakest among us attempt to prosper at the cost of the weak, failure is inevitable except, of course, for those with lives of higher value.

Published with permission from the American Thinker.

Link:
How redefining medicine has redefined the family - Lifesite

Embryology, the study of the formation and development of an embryo and fetus. Before widespread use of the microscope and the advent of cellular biology in the 19th century, embryology was based on descriptive and comparative studies. From the time of the Greek philosopher Aristotle it was debated whether the embryo was a preformed, miniature individual (a homunculus) or an undifferentiated form that gradually became specialized. Supporters of the latter theory included Aristotle; the English physician William Harvey, who labeled the theory epigenesis; the German physician Caspar Friedrick Wolff; and the Prussian-Estonian scientist Karl Ernst, Ritter von Baer, who proved epigenesis with his discovery of the mammalian ovum (egg) in 1827. Other pioneers were the French scientists Pierre Belon and Marie-Franois-Xavier Bichat.

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animal development: Embryo formation

Since the goal of development is the production of a multicellular organism, many cells must be produced from the single-celled zygote.

Baer, who helped popularize Christian Heinrich Panders 1817 discovery of primary germ layers, laid the foundations of modern comparative embryology in his landmark two-volume work ber Entwickelungsgeschichte der Thiere (182837; On the Development of Animals). Another formative publication was A Treatise on Comparative Embryology (188091) by the British zoologist Frances Maitland Balfour. Further research on embryonic development was conducted by the German anatomists Martin H. Rathke and Wilhelm Roux and also by the American scientist Thomas Hunt Morgan. Roux, noted for his pioneering studies on frog eggs (beginning in 1885), became the founder of experimental embryology. The principle of embryonic induction was studied by the German embryologists Hans Adolf Eduard Driesch, who furthered Rouxs research on frog eggs in the 1890s, and Hans Spemann, who was awarded a Nobel Prize in 1935. Ross G. Harrison was an American biologist noted for his work on tissue culture.

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Embryology | Britannica

London - The first "designer baby" conceived using a controversial screening technique is expected to be born next year.

An embryo has been implanted into a surrogate using IVF by US firm Genomic Prediction.

Nathan Treff, chief scientific officer at the New Jersey firm, told the Mail "there is now a pregnancy confirmed" and it is hoped the baby will be born in 2020.

It is understood the parents are a male couple in the US, who are having the baby using a surrogate mother.

The embryo has been selected through genetic sequencing to have a reduced risk of 11 diseases, including several types of cancer and diabetes. While such a test would be illegal in the UK, Genomic Prediction said it intends to apply for a licence with the watchdog Human Fertilisation and Embryology Authority.

Read more here:
World's first 'designer baby' to be born in a year - IOL

By Pip Murrison & Natasha Mosheim

Profile speaks to President of Students for Life Durham Jolle Lucas about her newly ratified society and the pro-life movement in Durham. An interview with President of Durham Students for Abortion Access can be found here.

Why are you pro-life?

I grew up in a Christian home. It is kind of assumed in that tradition that you are pro-life because we believe that humans are incredibly valuable, that life is a gift from God. But when I was in high school one of my friends asked me the hard question. She said, Well what would you do if a girl was raped or something? And I hadnt thought about that. I went home and I asked my mum that question. My mum just started crying and she looked at me and said well obviously thats horrendous and thats awful, but we dont kill children for the sins of their fathers. We are actually fighting for two victims, we are fighting for a woman and her baby, who were both hurt by someone who was abusive. I think because I heard that emotional, kind response, I became pro-life, it helped cement that.

Do you think that abortion will be abolished worldwide in our lifetime?

I hope that it will be abolished in our lifetime. I would really like to see women given more options, and the abortion numbers to decrease. When abortion was passed in both the UK and the US, especially in the US, the tagline was safe, legal and rare right. Well over 200,000 abortions in the UK is not rare, especially when upwards of 90% of those abortions are not because of health of the mother, they are not because of rape, because of a deadly problem or the foetus or anything like that, they are simply because of inconvenience.

Is abortion unacceptable in cases of rape?

I believe in embryology that life starts at conception. I believe that every human deserves human rights that includes the child. The woman who was raped, her body was violated by the rapist. When you choose abortion, you are also violating the life of the unborn child right, its a similar kind of crime just in a different way, I think that both are wrong. That doesnt mean that I dont have compassion, I think that rapists should be put behind bars at the very least. But I dont think that having an abortion would fix rape. I have done studies on post-abortion counselling and things like that, and its so important and vital that we understand how many women are suffering from post-abortion trauma. If a woman in a normal situation chooses to have an abortion and she suffers from post-abortion trauma, then you go to the woman who is already suffering from the trauma of rape and then add post-abortion trauma on top of that. Why would we want to add to the problem? I was violated, then I tried to get rid of the problem, so I violated and ended up killing another person. I just dont see abortion even in cases of rape as consistent or ultimately really caring, and nothing is going to undo it. We have to find the way thats going to create the least amount of trauma.

Is it ever okay to have an abortion? Even if mothers life at stake?

Pro-Lifers want to save as many lives as possible, hopefully mother and child but if it is a situation where we have to do something as if you do nothing the woman and the child will die, in that case we chose the operation that will save the most lives.

Many would argue that the right to choose abortion is a human right, how would you respond to that?

Some would argue its their human right. I would think that its not consistent and not correct because then youre disregarding the human right of the child. The child inside your body is not your body. Thats a separate human. No woman has two heads or two hearts. Its a separate body. And no person should be able to decide who is valuable and not. These children are just as valuable. But the only difference is somebody decided that they were valuable or not. I think we get into really really sticky territory as humans, when we start deciding that because someone is smaller than us, less capable than us, less able than us, maybe looks a little different than us, that we have the right to decide that they are not human. Because thats how we get the holocaust, thats how we get slavery, thats how we get things like racism and ableism and whatever else you want to call it. If we say that every person is valuable, then we have to include the unborn in that.

Donald Trump says he is Pro-Life but with caveats i.e. abortion is acceptable in cases of rape and incest. Obviously, you dont agree with the caveats, but do you support Trump, based on his Pro-Life stance?

Ive been really surprised with how pro-life President Trump has been, because I was concerned, and thought maybe hes just saying that to get the Republican vote, who knows. Im not one of those people that will say we have to agree on every single point in order for you to get my vote but Pro-Life was the main one and I think anything we can do to protect women and reduce abortion I think is a good thing.

Why do pro-life activists struggle to make their voices heard over the pro-choice campaign?

I think it is because its swept in with other things in Conservatism. Not because Im ashamed, but because I would be scared. Oftentimes there is that silent majority where you have one small group of people yelling really really loudly and everyone else is like I have my voice but I dont need to shout. That can be the case with people that are pro-life. If you say you are pro-life in the wrong crowd, youll get hate, youll get bullied, people will make fun of you and they will make assumptions about you and before you even have a chance to say anything about I care for women or that I spend a lot of time wanting to champion for women and things like that, theyll say you racist, bigoted, women hater, anti-feminist, Nazi. And youre just like, well youve already decided who I am, what more is there to say? So I think that that causes a lot of people to want to be silent.

You talk a lot about how being pro-life for you is tied up with female empowerment. Would you describe yourself as a feminist?

I generally dont use the term feminist because of what the feminist lobby stands for today, I dont agree with them on a lot of things. I dont agree with third wave feminism. I would agree with first and probably second wave feminism. Actually the first feminists were all pro-life. They were huge champions for women. A lot of what feminism is doing today is really just trying to turn women into men. I just dont understand that. What the original feminists were trying to do were to say we can be women, we can love being women and have jobs and vote and we dont have to become men to do that. That, to me, is what being feminist is and what I would like feminism to return to. To say we dont have to be men to be valuable people.

Do you think that the scare factor of having an unplanned pregnancy whilst at university drives students towards abortion? How would you advise someone who has an unplanned pregnancy?

I would say absolutely. Not every woman is the same, for some women it would not matter what the options were, they would just want the abortion. But for the majority of women I have spoken to, when I have said if were to get rid of everything that would be impeding you having this baby, be it funds or a house or a jobs or a boyfriend or whatever, they most often would say yes I would want this baby. I see a massive problem there, that if they had the support they would want their baby and our response is too bad, we will just give you an abortion any way. So I would encourage them to think 10, 30, 40 years down the road, and you look back and can say I made the right choice, the best and most loving choice for me and for this baby. I think all to often we think abortion is the undo button. What we dont talk about is how emotionally difficult it is to end the life of a child, to live with that, we live in a culture that tells women if you chose an abortion you should not feel bad about it, you should feel empowered and you should get over it.

Disclaimer: All views and research cited above are those of the interviewee and are not necessarily reflective of Palatinate.

Image by Jolle Lucas

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I believe that life starts at conception - Palatinate

Introduction

Key Events of Human Development during the first week (week 1) following fertilization or clinical gestational age GA week 3, based upon the last menstrual period.

The first week of human development begins with fertilization of the egg by sperm forming the first cell, the zygote. Cell division leads to a ball of cells, the morula. Further cell division and the formation of a cavity in the ball of cells forms the blastocyst. These notes also cover events before fertilization formation of both the egg and sperm, gametogenesis.

Initially, there is a halving of chromosomal content in the gametes (spermatozoa and oocyte) by the process called gametogenesis. Chromosomal content is then restored by fertilization, allowing genetic recombination to occur. This is then followed by a series of cell divisions without cytoplasmic growth. During this first week the egg, then zygote, morula then the blastula is moving along the uterine horn into the uterus for implantation in the uterine wall.

Implantation also begins in this first week, but will be covered in Week 2 notes, as the implantation process is completed by the end of the second week.

Human blastocyst week 1 movies, 3 above movies together in single table.

Movie - Pronuclear Fusion | Movie - Parental Genomes

Conceptus - term refers to all material derived from this fertilized zygote and includes both the embryo and the non-embryonic tissues (placenta, fetal membranes).

Within the early zygote, at the 2 pronuclei stage, the male pronucleus is "reprogrammed" by the demethylation of the paternal genome. Image sequence shows the mouse zygote at pronuclear stages[2], where the male pronucleus initially contains methylcytosine (5mC, red) oxidises to form hydroxymethylcytosine (5hmC, green).

5mC - 5-methylcytosine (red). 5hmC - 5-hydroxymethylcytosine (green) formed by enzymatic oxidation of 5mC.

Mouse zygote mitosis[2]

Cleavage of the zygote forms 2 blastomeres and is cleavage with no cytoplasm synthesis.

Cell division within these cells is initially synchronous (at the same time), then becomes asynchronously (at different times).

Carnegie stage 2

Carnegie stage 3

Two forms of cellular junctions Figure 21-69. The blastula

Blastocyst Hatching - zona pellucida lost, ZP has sperm entry site, and entire ZP broken down by uterine secretions and possibly blastula secretions. Uterine Glands - secretions required for blastocyst motility and nutrition

There are several important changes that occur in this new diploid cell beginning the very first mitotic cell divisions and expressing a new genome.

The oocyte arrested in meiosis is initially quiescent in terms of gene expression, and many other animal models of development have shown maternal RNAs and proteins to be important for early functions.

The new zygote gene expression is about cycles of mitosis and maintaining the toptipotency of the stem cell offspring cells.

The morula gene expression supports the formation of two populations of cells the trophoblast (trophectoderm) and embryoblast (inner cell mass), each having different roles in development, while maintaining the toptipotency of these populations.

Current research is now also pointing to non-genetic mechanisms or epigenetics as an additional mechanism in play in these processes.

The following figure is from a recent study[4] using video and genetic analysis of in vitro human development during week 1 following fertilization.

A recent paper has measured telomere length in human oocyte (GV, germinal vesicle), morula and blastocyst and found changes in this length in preimplantation embryos.[5] Telomeres are the regions found at the ends of each chromosome and involved in cellular ageing and the capacity for division. The regions consist of repeated sequences protecting the ends of chromosomes and harbour DNA repair proteins. In the absence of the enzyme telomerase, these regions shorten during each cell division and becoming critically short, cell senescence occurs.

See Week 1 - Abnormalities

Dizygotic twins (fraternal, non-identical) arise from separate fertilization events involving two separate oocyte (egg, ova) and spermatozoa (sperm).

Monozygotic twins (identical) produced from a single fertilization event (one fertilised egg and a single spermatazoa, form a single zygote), these twins therefore share the same genetic makeup. Occurs in approximately 3-5 per 1000 pregnancies, more commonly with aged mothers. The later the twinning event, the less common are initially separate placental membranes and finally resulting in conjoined twins.

Table based upon: Twinning. Hall JG. [6]

Embryo Week: Week 1 | Week 2 | Week 3 | Week 4 | Week 5 | Week 6 | Week 7 | Week 8 | Week 9

Cite this page: Hill, M.A. (2019, October 20) Embryology Week 1. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Week_1

Link:
Week 1 - Embryology

Embryology around the world (use the translate link by clicking Expand at the top of each page to change to your language) - embryologie (German, French, Dutch, Czech), embriologa (Spanish, Italian, Portuguese), embryologi (Norwegian), embryologia (Finnish), embryoleg (Welsh), embriologi (Indonesian), embrayolohiya (Filipino), (Greek), (Russian), (Japanese), (Chinese), (Korean), (Hebrew), (Arabic), (Persian), (Tamil), (Marathi), (Thai)

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Embryology