Tag: zygotes

Bioethics Blogs

The Very Early Embryo & Its Moral Signifiance

by Andrew J. Prunty

As technology and biological research continue to develop in the twenty-first century, it is necessary to address and further define the ethical considerations of embryonic research and the appropriate rights that may limit the extent of human research on zygotes, blastocysts, and fetal scientific advancement. Because the area of harvesting embryonic stem cells remains significantly undefined, both legally and morally, there are vastly different opinions between researchers and bioethicists, mainly because of ethical limitations, on the rights that should be granted to cells with the potential to develop into human beings and the consequences of neglecting significant scientific research or advancement.

Current laws in the United States differ at the federal and state level, but there is no consistency in recognizing human embryos as humans, or affording them the same legal rights granted to a child; in fact, legal precedent actually detracts certain rights from developing embryos, favoring a human’s ability to destroy a potential human being (i.e. Roe v. Wade[i]) or the categorization of embryos as property (i.e. Davis v. Davis[ii], A.Z. v. B.Z.[iii], Marriage of Dahl[iv], or Reber v. Reiss[v]). These case law samples suggest the courts’ inability to reach a conclusion as to what is the status of an embryo.

The debate is not only circumscribed to matters of research, but to fundamental controversial and intertwined issues of bioethics such as: when life begins, embryonic stem cells, fetal rights, abortion, et cetera. All these topics are contentious and when one topic arises, they begin to comingle.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

Ethical questions about mitochondrial replacement in humans. Three parents babies

We thus consider it necessary to establish a moratorium on their use in humans, at least until more is known about these aspects. If this knowledge is obtained, ethical questions would still remain to be resolved, among which we consider the most relevant to be those related to the dignity and identity of the human embryo.

Children with two mothers and a father

In January 2017, the prestigious scientific journal Bioethics published a special edition dedicated to the ethical aspects of nuclear transfer techniques aimed at preventing the transmission of mitochondrial diseases, a topic that we have extensively addressed in our Observatory (see HERE).

Its editorial, Ethics of mitochondrial replacement, starts by referring to the recent birth of the first baby resulting from these techniques (see HERE). It then provides a brief description of the main characteristics of mitochondrial diseases, which are inherited exclusively from the mother. It explains that mothers who carry mutations in their mitochondrial DNA (mtDNA) face the uncertainty of not knowing if their genetic children will or will not inherit a serious mitochondrial disease. However the emergence of mitochondrial replacement techniques (MRT) offers these mothers hope, as healthy mitochondria from a donor are used to replace those of the mother. These techniques are maternal spindle transfer (MST) and pronuclear transfer (PNT), which consist, respectively, in removing the nucleus from a healthy egg or zygote, which will keep its mitochondria. The nucleus of the mother’s oocyte (patient or carrier of the mutation) or of another zygote obtained by fertilising the mothers egg is then transferred into the enucleated oocyte or zygote.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

Mitochondrial replacement used for the first time in viable human embryos

An article has been recently published in scientific journal Nature (534; 383–386, 2016), describing the application of mitochondrial replacement techniques in viable human embryos, considering this experiment as the first preclinical study in humans in this field.

The technique used was pronuclear transfer, in which the authors had modified the application protocol to improve its efficacy. This technique had been previously tested on human embryos left over from in vitro fertilisation treatments, but for this reason, these experiments are not considered preclinical studies. Nevertheless, the investigators observed that the method used in the studies with abnormally fertilised human zygotes were not well tolerated by normally fertilised zygotes, so they developed an alternative approach, bringing forward the time at which the pronuclei are transferred and modifying the transfer conditions.

In our opinion, both the previous experiments and the new study are ethically unacceptable, as they manipulate and destroy human embryos. While not surprising that this has not been taken into account in any of the studies, it is striking that further steps continue to be taken in a field whose permissibility not been agreed by the scientific community, on the grounds that it is a modification of the germ line and due to the safety concerns that it raises.

Foto: Shutterstock

La entrada Mitochondrial replacement used for the first time in viable human embryos aparece primero en Observatorio de Bioética, UCV.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

Hateful politics infiltrate human genome editing debate in France

A recent campaign calling for a ban on “transgenic” human embryos was launched by one of France’s most prominent organizations fighting for “science”-backed “one-man-one-woman” families, and the exclusion of all other forms.

“Stop GMO Baby: Yes to therapeutic progress, no to transgenic embryos” (image via Alliance VITA).

Since March 24, more than 15,500 people in France have signed a Change.org petition started by Alliance VITA declaring (translated from French*):

“I ask my country to engage with all urgency to obtain an international moratorium – that is to say an immediate stop – on the genetic modification of human embryos, especially via the technique CRISPR-cas9.”

*all French materials and quotations presented in English in this post have been translated using Google and my college-level French. Suggested revisions to translations are welcome and will be noted. Alliance VITA offers some materials on its website in English.

In that time, volunteers have canvassed cities around France, handing out brochures explaining the breakthrough CRISPR genome editing technology, and tweeting pictures of their advocacy using Flickr and the hashtags: #StopBébéOGM, #ProtectHumanity, and #CRISPR-Cas9.

Alliance VITA’s opposition to using human gene editing for reproduction is widely shared, including by my organization, the Center for Genetics and Society. But a closer look at the Stop GMO Baby campaign in France reveals a troubling and at times explicitly hateful politics infiltrating the human genome editing debate. A polarization of the conversation about heritable human genetic modification along “right to life” and “natural family” fault lines threatens to derail public conversations about responsible regulation of science and medicine that serves the public interest.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

UK Researchers Now Say Three-Person Embryo Technique Doesn’t Work; Propose New Method

In February 2015, the UK decided to create a controversial exception to its law against any form of human germline modification to allow the creation of “three-person embryos” to prevent the transmission of some mitochondrial disease. Then and now, unresolved scientific concerns remained, and many people have been waiting to see whether the science will indeed come through.

Adding to anxiety to see these data is the enormous global attention on a different technology proposed for human genetic modification: the gene editing technique CRISPR, and current controversy over varied attempts to try it on human embryos.

However, there is only one central place where the mitochondrial research is being carried out in the UK – the Wellcome Trust Centre for Mitochondrial Research at Newcastle University. But despite opening its doors in 2012 and encouraging excitement about the importance of  this research, none of the specific research requested by the Human Fertilisation and Embryology Authority (HFEA) had been published until now.

Today, that changed. Well-known Newcastle researchers including Mary Herbert and Douglass Turnbull have just published an update to their six-years-old Nature paper, which originally described how their preferred form of mitochondrial replacement – pronuclear transfer (PNT) – “has the potential to prevent the transmission of mtDNA disease in humans.”

Shockingly, their new paper reports that the proof-of-concept studies upon which everyone had been basing their enthusiasm “were not well tolerated by normally fertilized zygotes.” In other words, the scientific basis for the controversial UK law and HFEA policy change turns out to have been unfounded. It did not work.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

New CRISPR-EZ Method Makes Genome Editing Much Easier in Mice

May 31, 2016

(News-Medical) – To do that, they need to knock out or modify specific genes in lab animals – in particular, mice – and see what goes awry. Today’s gold standard for creating these “knockouts” or “knockins” is to edit the genes inside mouse embryonic stem cells, use these cells to create mosaic mice, and then crossbreed the mice to get a pure genetic strain. Because of CRISPR-Cas9’s ability to precisely alter or replace genes, the editing is increasingly being done directly in the fertilized egg, or early embryo. The new method, called CRISPR-EZ (CRISPR RNP electroporation of zygotes), makes genome editing in mouse embryos even easier.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics Blogs

Hacking CRISPR: Patents, Gene Therapy & Embryos

Bruiseless bananas, vegan cats, pig-to-human transplants, and super-muscular dogs: can you tell the real CRISPR projects from fake ones? It’s getting harder these days, as the latest generation of “gene editing” tools are not only (relatively) quicker, cheaper, and easier than any previous genetic engineering method, but have become “probably the fastest-spreading technology in the history of biology.” As it spreads, researchers the world over are discovering new hacks, complexities, and limitations for CRISPR. Here’s a round-up of recent developments in this booming arena.  

Trending globally: gene editing experiments with human embryos

On April 8, news broke that the second paper documenting CRISPR experiments in human embryos had been published. Researchers at Guangzhou Medical University sought to enhance nonviable embryos leftover from IVF with a naturally occurring mutation that confers HIV resistance: CCR5Δ32.


(Image via Wikimedia: Guangzhou Circle)

The experiments were largely unsuccessful: only 4 of 26 embryos wound up with a copy of the desired mutation, and none had the two copies that would be needed to resist the virus. Mosaicism was also a problem. A year prior in April 2015, the first research using CRISPR in tripronuclear human zygotes was reported by a team at Sun Yat-sen University in the obscure journal Protein & Cell, after Nature and Science turned it down. This second paper was reported in “an obscure reproductive journal” published by the American Society of Reproductive Medicine (the same body that releases non-enforceable guidelines into the void of any regulation over assisted reproductive technologies in the United States).

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

Ethical assessment of mitochondrial replacement to prevent transmission of hereditary diseases

Are there any ethical differences to consider between the two existing mitochondrial replacement techniques? A recent article in Bioethics (Bioethics 29; 631–638, 2015) defends the advisability of using pronuclear transfer (PNT) compared to maternal spindle transfer (MST) to prevent the transmission of certain hereditary mitochondrial diseases.

MST consists of extracting the nuclear DNA from the ovum (egg) of the mother (whose mitochondria are “sick”) and placing it in a healthy enucleated ovum from a donor. Thus, the resulting ovum contains nuclear DNA from the mother and healthy mitochondria from the donor. The ovum is then fertilised in vitro. In contrast, in PNT, the replacement does not occur between ova, but between zygotes. In the first step, two ova are fertilised: one from the mother, containing the “sick” mitochondria, and one from a donor with healthy mitochondria. The DNA replacement occurs between zygotes, resulting in a zygote with the genetic contribution of the parents and the mitochondria of the donor; the other zygote is discarded.

The authors argue that, since MST is applied to the female gamete before fertilisation, it can somehow be said that the sole function of the technique is to allow the mother to have children of her own without the disease. In contrast, since PNT is applied to the zygote, this technique can be considered to act directly on the health of an already existing child, to cure it rather than to satisfy the mother’s desire to have healthy children. From this, the authors draw two conclusions. First of all, that the parents have stronger moral reasons to accept PNT than to accept MST, since not using PNT would directly harm their children, which would not be the case of MST.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

Interview: Carrie D. Wolinetz of the NIH on gene editing

Interview: Carrie D. Wolinetz of the NIH on gene editing

New gene editing technologies like the CRISPR-Cas9 technique hold great promise for medicine and the biological sciences. Some researchers say we may soon be able to eradicate infectious diseases like malaria, and edit HIV out of the genome of AIDS sufferers. Others believe we can use gene editing techniques to make animal organs suitable for human transplants. 

Yet there are many ethical questions attentant to research in the area, and ethicists are struggling to catch up with scientists eagerly refining the new gene editing techiques. Recently I spoke with Dr. Carrie D. Wolinetz, assistant director for Science Policy at the National Institutes of Health, about various concerns raised by bioethicists about gene editing.

Dr. Wolinetz worked on biomedical research policy issues as the Deputy Director for Federal Affairs at the Association of American Universities (AAU) and the Director of Scientific Affairs and Public Relations at the Federation of American Societies for Experimental Biology (FASEB). She also served as the President of United for Medical Research, a leading NIH advocacy coalition. Outside of NIH, Dr. Wolinetz teaches as an Adjunct Assistant Professor at Georgetown University in the School of Foreign Service’s program on Science, Technology & International Affairs.

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Xavier Symons: The NIH is funding research into gene editing, but has stopped short of assisting projects involving human embryos. Why?

Carrie D. Wolinetz: On April 29, 2015, the NIH Director, Dr. Collins, issued a statement that “NIH will not fund any use of gene-editing technologies in human embryos.”

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.

Bioethics News

Genome editing CRISPR-Cas9. Biomedical and ethical considerations

Since the emergence in 2012 of the genome editing technique known as CRISPR-Cas9 [1], its use has rapidly expanded, as reflected in a notable increase in the number of publications, patented applications and funding awarded for this research area within a short period of time. A very comprehensive report has recently been published in international science journal Nature, explaining the trajectory of CRISPR-Cas9 and the different fields of application of this technique [2], which we shall discuss in this report.

The technique consists of using an RNA fragment that has a dual function: On one hand, it acts as a guide to find the piece of DNA to be modified and binds to it, while on the other, it recruits a molecule whose function is to cut the DNA, as if it were scissors (Cas9 enzyme). This enables the desired pieces of DNA to be cut, allowing the modification or removal of specific sequences. Unlike other gene-editing methods, CRISPR-Cas9 is cheap (around 30 US dollars per sequence), quick, and easy to use, and as such has been widely implemented in numerous laboratories worldwide. Furthermore, it can be applied in a large number of entities, and does not have to be limited to traditional model organisms. CRISPR pioneer Jennifer Doudna of the University of California, Berkeley, is compiling a list of CRISPR-altered creatures, which to date “has three dozen entries, including disease-causing parasites called trypanosomes and yeasts used to make biofuels” [2].

Nevertheless, while CRISPR appears to have much to offer, some scientists are concerned that the breakneck pace at which the technology is developing leaves little time for adequately assessing the ethical and safety issues that might arise as a result of these experiments.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.