Changes may allow scientists to grow human embryos longer


London (AP) — A new guideline released Wednesday recommends removing decades-old barriers to stem cell research and allowing researchers to grow human embryos longer under limited conditions. I am.

The 14-day rule, an international ethical standard that limits laboratory research on human embryos, has been in force for decades and is included in the law in countries such as the United Kingdom and Australia. Scientists were previously required to destroy laboratory-grown human embryos before reaching 14 days.

Some researchers supported revising the rules to further study the development process, but opponents said that such experiments crossed moral boundaries at any stage and changes proceeded with the study. It is unclear if it is.

Robin Lovell-Bad, a stem cell expert at the Click Institute in London and chair of the group behind the new guidelines, said the initial restrictions were arbitrary and the critical period of embryogenesis (usually 14 days). 28th) said it hindered the study.

“I think there are a lot of birth defects quite early in this period,” says Lovell-Badge. “A better understanding of these early stages may allow us to adopt simple steps to reduce the amount of suffering.”

The last updated guideline in 2016 was published by the International Society for Stem Cell Research. The standard is widely accepted by countries, medical journals, and the research community. It did not specify how long the embryo could grow.

In order for British scientists to begin embryo production for more than two weeks, the legislation governing such studies will need to be changed. Even if the rules are relaxed, they still need “strong reviews” by national regulators, Ravel Badge said.

Kathy Niakan of the University of Cambridge, who helped draft the guidelines, added that it would be “irresponsible” for scientists to expand their research into human embryos, saying it was “not a green light.”

Niakan said scientists, regulators, funders and the general public need to be involved in a public dialogue to discuss potential objections. She said that widespread public support is needed before proceeding and that countries may use specialized surveillance processes to assess the scientific benefits of research.

Marcy Darnovsky, Secretary-General of the Center for Genetics and Society, said the new guidelines are still lacking in scientific justification.

“Can we really tell you something meaningful about miscarriage or embryonic development when the embryo is in an extracorporeal Petri dish?” She said.

Darnovsky was also concerned that the guidelines did not impose limits on the period during which human embryos could potentially grow.

The Society also provided advice on other controversial stem cell issues, including requiring strict monitoring to transfer human embryos to the uterus after donation of mitochondrial disease. This is the process of creating an embryo using two eggs and one sperm.

The guidelines currently prohibit gene editing that conveys change to future generations. This is similar to the work done by Chinese scientist He Jiankui, who surprised the world when he announced that he had made his first genetically edited baby in 2018.

Such work is currently banned, but Lovell-Badge and others may someday be allowed “if proven safe enough and used in sufficiently limited circumstances”. I admit that I have sex. At Stanford University.

The guidelines also prohibit the cloning of humans, the transplantation of human embryos into the uterus of animals, and the creation of human-animal chimeras, and such work is “scientifically unfounded or ethically. I’m concerned. “

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The Associated Press’s Department of Health Sciences is supported by the Department of Science Education at the Howard Hughes Medical Institute. AP is solely responsible for all content.

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