【美国科学家正在开发基因编辑的人类胚胎】

【美国科学家正在开发基因编辑的人类胚胎】去年11月,一位中国科学家公布了他编辑过双胞胎胚胎基因组的消息引起全球轰动。近来哥伦比亚大学的生物学家Dietrich Egli博士正在对人类胚胎进行基因编辑,并声称自己的实验纯粹是出于研究目的,在开发仅一天之后就摧毁了胚胎。但如果最终目标是从人类的DNA中基因编辑疾病,那么这些胚胎将必须完全发育。在疾病预防和“设计师婴儿”之间划清界线,将会是人类无休止的生命伦理辩论的素材。

US scientist is developing gene-edited human embryos: Biologist who slammed China's human gene-editing as 'genome vandalism' is conducting his own tests

  • Dr Dietrich Egli is using a gene-editing tool to alter human embryos 
  • In November, a Chinese scientist announced that he had edited the genes of a pair of twin girls born that month - a world-first 
  • Dr Egli called that work 'genome vandalism' 
  • Now, he's undertaken a similar experiment but claims his is more responsible because he only lets the embryos develop for one day  

A New York scientist is attempting to edit the DNA of human embryos - a similar and controversial method to what Chinese scientists recently came under fire for doing just months ago.

Dr Dietrich Egli, a Columbia University developmental cell biologist, is using the Nobel Prize-winning CRISPR gene-editing method to try to repair DNA mutations in early embryos, he told NPR.

In November, a Chinese scientist went public with the news that he had already edited the genomes of twin embryos - and that they had developed and already been born a pair of healthy baby girls.

Dr Egli himself called that work 'genome vandalism,' but claims that his own experiments are purely for research purposes and intended to determine the safety of the procedure.

Columbia University biologist Dr Dietrich Egli is gene-editing human embryos and allowing them to develop for one day amid controversy over first 'designer babies' created in China - that even he criticized (file) 

Columbia University biologist Dr Dietrich Egli is gene-editing human embryos and allowing them to develop for one day amid controversy over first 'designer babies' created in China - that even he criticized (file)

Currently, he told NPR, he is destroying the embryos after just one day of development, but in order to fully understand the safety of the procedure, Dr Egli will have to allow the embryos to develop for longer, raising serious ethical questions.

When it was developed, the CRISPR technique - which works like a chemical cut and paste, finding and removing faulty genes before replacing them with better copies - was hailed as hope for the end of genetic diseases.

In theory, this could mean preventing any babies from being born with genetic abnormalities, and no or low risks for disease with genetic components, a prospect that's appealing to parents on a personal level and could reduce the burden of disease on public health.

But that could be a slippery slope.

If scientists can edit out genes for problems, why couldn't they edit in genes for traits parents prefer?

Drawing a line between disease prevention and 'designer babies' is fodder for nearly endless bioethical debate.

When Dr He Jiankui, a scientist at the Southern University of Science and Technology (which insists it had nothing to do with the experiment) in China used CRISPR to edit the genomes of the twin embryos, it was to to prevent them from inheriting their father's HIV.

But critics - of which there were many, and they were furious - argued the girls could have been protected from infection by other tried, true and empirically tested methods.

Skepticism and, perhaps more importantly, deep uncertainty surround the Chinese twins (Lulu and Nana) because the procedure was done in secrecy and Dr Jiankui has not published a paper about the research.

Dr Egli claims to be taking a more cautious approach.

He is using CRISPR to repair genes linked to form of inherited blindness.

But he says that his work is not intended to create gene-edited babies, but rather for 'research purposes' to test the safety of his method.

'We can't just do the editing and then hope everything goes right and implant that into a womb. That's not responsible,' Dr Egli told NPR.

'We have to first do the basic research studies to see what happens. That's what we're doing here.'

One by one, Dr Egli is 'dipping' sperm from men with the congenital of blindness (called retinitis pigmentosa) into a solution containing the CRISPR tool programmed to snip away the faulty genes.

He then injects the sperm into the egg, which has healthy copies of the eye disease gene. The idea is that when they combine, the egg's healthy copy of the gene will sub-in.

After the deceptively simple repair process is done, Dr Egli said that he just lets the embryo mature for one day of observation to see if the technique appears safe up to that point.

But, of course, if the ultimate goal is to gene-edit the disease out of human's DNA, then eventually those embryos will have to develop fully.

Law and regulation in the US (and abroad) are still grappling with abortion and the definition of conception. They have a long way to go to catch up with fundamentally altering babies.

Until it does, work like Dr Egli's will remain an area of nearly un-paralleled excitement in the medical field, and certainly one of the most divisive.

原文链接:https://www.dailymail.co.uk/health/article-6657861/US-scientist-developing-gene-edited-human-embryos-slamming-similar-Chinese-research.html


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