Scientists around the world called on Thursday that a controversial experiments searching for “disturbing” human embryos, after a team of Chinese experts publish details of their slow but significant attempts to open suspend this new frontier in science.
The work of the Chinese team, which was reported on Wednesday in Nature News, appeared in an obscure scientific journal called Protein and Cell. In this, the researcher of gene function Junjiu Huang of Sun Yat-sen University in Guangzhou, describe with colleagues how they altered a few embryos from a fertility clinic.
Embryos were classified as viable and had no chance to give birth to a human life, because they had an extra set of chromosomes after being fertilized by two sperm.
The researchers “tried to change the gene responsible for beta-thalassemia, a potentially fatal blood disorder, using a technique known as genetic edition CRISPR / Cas9 “said the report in Nature News.
Chinese scientists also said they had “great difficulty” and that his work shows “the urgent need to improve this technique to be applied in medicine”.
They injected 86 embryos with a corrected version the defective gene and waited 48 hours. They survived 71, of which 54 were examined. The researchers found that only 28 “were spliced successful” and that only a fraction of them contained the new gene, the report said.
“If you want to apply this technique to embryos normal, need to gene replacement rate is 100 percent, “Huang was quoted by the magazine. “It’s the reason why we suspended the experiment, because we think this technique is still very immature,” he said.
unexpected mutations
Even more troubling was “surprisingly high number” of unintended mutations that appeared during this process of genetic edition: a much higher rate in view of previous studies of genetic edition in mice or human cells
Such mutations can be dangerous and are the main reason why there are many concerns in the scientific community since last year began to spread rumors about the work of the Chinese team.
these experiments Critics warn that if science follows this path, could generate effects on future generations who can not be suspected today. Furthermore, the issue of genes could open a new door to eugenics (breeding) of humans (as practiced with dogs, for example), to encourage desirable traits.
In response to this report, the Alliance for Regenerative Medicine reiterated his call for an end to this research. “Given the important implications for ethical and safety having to modify the DNA (germline) human reproductive cells, this research is extremely premature,” said the statement from an international organization that brings together 200 companies dedicated to the study of living organisms.
“It is unacceptable to proceed with this type of investigation at this time. We asked for a voluntary global moratorium on this kind of experiments to yield rigorous and transparent talks on its law and policy, “said AMR.
It is believed that at least four other teams of Chinese researchers are conducting similar studies, said the report by Nature News. “This latest study highlights something we already knew: we need to stop this kind of research and have long conversations to decide which direction to take,” said Edward Lanphier his part, President Sangamo BioSciences in Richmond, California, also cited in the study of Nature News.
AFP
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