It is happening!!!!!!
Chinese scientists genetically modify human embryos
Rumours of germline modification prove true — and look set to reignite an ethical debate
In a world first, Chinese scientists have reported editing the genomes of human embryos. The results are published in the online journal Protein & Cell
and confirm widespread rumours that such experiments had been conducted — rumours that sparked a high-profile debate last month about the ethical implications of such work.
In the paper, researchers led by Junjiu Huang, a gene-function researcher at Sun Yat-sen University in Guangzhou, tried to head off such concerns by using 'non-viable' embryos, which cannot result in a live birth, that were obtained from local fertility clinics. The team attempted to modify the gene responsible for β-thalassaemia, a potentially fatal blood disorder, using a gene-editing technique known as CRISPR/Cas9. The researchers say that their results reveal serious obstacles to using the method in medical applications.
"I believe this is the first report of CRISPR/Cas9 applied to human pre-implantation embryos and as such the study is a landmark, as well as a cautionary tale," says George Daley, a stem-cell biologist at Harvard Medical School in Boston, Massachusetts. "Their study should be a stern warning to any practitioner who thinks the technology is ready for testing to eradicate disease genes."
The paper by Huang's team looks set to reignite the debate on human-embryo editing — and there are reports that other groups in China are also experimenting on human embryos.
The technique used by Huang’s team involves injecting embryos with the enzyme complex CRISPR/Cas9, which binds and splices DNA at specific locations. The complex can be programmed to target a problematic gene, which is then replaced or repaired by another molecule introduced at the same time. The system is well studied in human adult cells and in animal embryos. But there had been no published reports of its use in human embryos.
Huang and his colleagues set out to see if the procedure could replace a gene in a single-cell fertilized human embryo; in principle, all cells produced as the embryo developed would then have the repaired gene. The embryos they obtained from the fertility clinics had been created for use in in vitro fertilization but had an extra set of chromosomes, following fertilization by two sperm. This prevents the embryos from resulting in a live birth, though they do undergo the first stages of development.
Huang’s group studied the ability of the CRISPR/Cas9 system to edit the gene called HBB, which encodes the human β-globin protein. Mutations in the gene are responsible for β-thalassaemia.
The team injected 86 embryos and then waited 48 hours, enough time for the CRISPR/Cas9 system and the molecules that replace the missing DNA to act — and for the embryos to grow to about eight cells each. Of the 71 embryos that survived, 54 were genetically tested. This revealed that just 28 were successfully spliced, and that only a fraction of those contained the replacement genetic material. “If you want to do it in normal embryos, you need to be close to 100%,” Huang says. “That’s why we stopped. We still think it’s too immature.”
His team also found a surprising number of ‘off-target’ mutations assumed to be introduced by the CRISPR/Cas9 complex acting on other parts of the genome. This effect is one of the main safety concerns surrounding germline gene editing because these unintended mutations could be harmful. The rates of such mutations were much higher than those observed in gene-editing studies of mouse embryos or human adult cells. And Huang notes that his team likely only detected a subset of the unintended mutations because their study looked only at a portion of the genome, known as the exome. “If we did the whole genome sequence, we would get many more,” he says.
Huang says that the paper was rejected by Nature and Science, in part because of ethical objections; both journals declined to comment on the claim. (Nature’s news team is editorially independent of its research editorial team.)
He adds that critics of the paper have noted that the low efficiencies and high number of off-target mutations could be specific to the abnormal embryos used in the study. Huang acknowledges the critique, but because there are no examples of gene editing in normal embryos he says that there is no way to know if the technique operates differently in them.
Still, he maintains that the embryos allow for a more meaningful model — and one closer to a normal human embryo — than an animal model or one using adult human cells. “We wanted to show our data to the world so people know what really happened with this model, rather than just talking about what would happen without data,” he says.
But Edward Lanphier, one of the scientists who sounded the warning in Nature last month, says: "It underlines what we said before: we need to pause this research and make sure we have a broad based discussion about which direction we’re going here." Lanphier is president of Sangamo BioSciences in Richmond, California, which applies gene-editing techniques to adult human cells.
Huang now plans to work out how to decrease the number of off-target mutations using adult human cells or animal models. He is considering different strategies — tweaking the enzymes to guide them more precisely to the desired spot, introducing the enzymes in a different format that could help to regulate their lifespans and thus allow them to be shut down before mutations accumulate, or varying the concentrations of the introduced enzymes and repair molecules. He says that using other gene-editing techniques might also help. CRISPR/Cas9 is relatively efficient and easy to use, but another system called TALEN is known to cause fewer unintended mutations.
The debate over human embryo editing is sure to continue for some time, however. CRISPR/Cas9 is known for its ease of use and Lanphier fears that more scientists will now start to work towards improving on Huang's paper. “The ubiquitous access to and simplicity of creating CRISPRs," he says, "creates opportunities for scientists in any part of the world to do any kind of experiments they want.”
A Chinese source familiar with developments in the field said that at least four groups in China are pursuing gene editing in human embryos.
The Chinese are planning to produce superbabies, which will ensure their total world domination.
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some of the comment sections
Quote:Mengele thought he was doing a great service to humanity with his experiments, too...
Quote:Ban it? LOL! Bring on the freak show. Now that we've decided homosexual "marriage" is legitimate, Pandora's Box is OPEN.
Quote:Moral, legal, ethical objections aside....'If it can be done by man, it will be done by man'
Quote:What are they afraid of? China may be willing to pursue a eugenic strategy that might make their nation the greatest on Earth, while others pursue anti-eugenic ideologies that are illogical.
Eugenics and genetic engineering could make China the guiding light for all mankind.
Quote:Here we go it seems allowing the powerful agro-chemical interest to force us to have GM foods with unknown health problems ,plus the already current bad effects on the environment and wildlife bio-diversity ,and super weeds taking over so even more powerful chemical needed.Yet when it comes a human embryo shock horror from the God lobby prime time , hypocrisy,which has held back progress to a more enlightened compassionate world back.As it is the claim that we need GM to feed the world is another con,when there is no need for it , when billions of tons of food are wasted ,hundreds of millions of tons grown for bio-fuels annually ,food prices and supplies allowed to be manipulated on the worlds stock markets,money and hypocrisy rule OK...
Quote:Of all the nations on Earth, the Chinese are among the few who openly support eugenics and the advancement of human potential. This is a grand new frontier, and what they're doing is necessary, commendable and courageous. There will always be risks and ethical issues involved in any major scientific project, but as always, if nothing is ventured, then nothing will be gained.