Scientists from around the world called for Thursday, April 23, 2015, that a controversial experiments that seek to “alter” human embryos are suspended , after a team of Chinese experts publish details of their slow but significant attempts to open this new frontier in the science .
The work of the Chinese team, which was reported in Wednesday’s Nature News , appeared in an obscure scientific journal called Protein and Cell.
this, the researcher of gene function Junjiu Huang –of the Sun Yat-sen University of Guangzhou– and his colleagues describe how they altered a embryos from a fertility clinic .
Los embryos were already qualified as unworkable and had no chance to give birth to a human life, because they had an extra set chromosome after being fertilized by two spermatozoa.
The researchers “tried to modify the gene responsible for the beta-thalassemia , a potentially fatal blood disorder, using a technique of genetic edition known as CRISPR / Cas9 “said the report in Nature News.
The 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 of the defective gene and waited 48 hours. They survived seventy one, 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 normal embryos , require that the rate of gene replacement is 100%,” 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.
unforeseen 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 Edition gene in mice and human cells .
Tales 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.
Critics of these experiments warn that if science follows this path, could generate effects on future generations who can not be suspected today.
In addition, the edition of genes could open a new door to the Eugenics (breeding) of humans-as that 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, according to an email sent to AFP
“Given the important implications for ethics and security has modified DNA cells human reproductive (the germ line), 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 continue this type of research at this time. Ordered a voluntary worldwide moratorium of this kind of experiments to yield rigorous and transparent talks on its legality and its policy, “said AMR.
It is believed that at least four other teams of Chinese researchers are conducting similar studies, said the report Nature News
“This latest study highlights something we already knew: we need to stop this kind of research and have long conversations to decide what direction we take.” he said on his part Edward Lanphier president Sangamo BioSciences in Richmond, California, also cited in the study of Nature News.
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