World First: Scientists Genetically Modify Lab-Made Human Embryos

[Karamjit]

The technique they used to edit the DNA of the human embryos could pave the way for the engineering of designer babies

Scientists working with the Sun Yat-Sen University in Guangzhou, China, claim to have genetically modified several laboratory-made human embryos. The research project, detailed in a paper in the journal Protein & Cell, is hailed as a world first.

Although this probably wasn't the team's intention, the news about the making of the first ever edited human embryos has sparked a heated discussion about how the technique used by the Sun Yat-Sen University could lead to designer babies and the ethics of it all.
How the embryos were genetically altered

In the report detailing their work, the Chinese scientists explain that the embryos they worked with were obtained from local fertility clinics in the city of Guangzhou in China and that they were all non-viable, meaning that they were abnormal and couldn't have resulted in a live birth.

To alter their genetic makeup, the researchers treated the embryos with an enzyme complex dubbed CRISPR/Cas9, which allowed them to cut and bind DNA at specific locations.

Having injected the embryos with CRISPR/Cas9, the Sun Yat-Sen University specialists managed to edit a gene dubbed HBB. The reason they targeted this gene and not some other one was because the study was intended to test DNA editing as a means to tackle genetic diseases.

Thus, investigations carried out over the years have shown that mutations in the HBB gene correlate with a potentially fatal blood disorder known as β-thalassaemia. Hence, editing the problematic gene means eliminating the risk for this disease.

When subjected to genetic editing, the human embryos all comprised just one cell. Once treated with the CRISPR/Cas9 enzyme complex and provided with the molecules needed to replace the removed genetic material, they were left to their own devices for 48 hours.
Not a very impressive success rate

Following the rest period, the scientists checked up on their Petri dishes and found that, of the 86 embryos they experimented on, a total of 71 survived the procedure. Of these embryos, only 28 showed signs of proper DNA breakage and just 7 contained the replacement genetic material.

While just 7 of the human embryos were genetically altered according to plan, many others displayed mutations that the researchers never wanted to happen. Consequently, the study was halted.

“If you want to do it in normal embryos, you need to be close to 100%. That’s why we stopped. We still think it’s too immature,” researcher Sun Yat-Sen University Junjiu Huang told the press in an interview, as cited by Nature.

“Their study should be a stern warning to any practitioner who thinks the technology is ready for testing to eradicate disease genes,” added specialist George Daley with the Harvard Medical School in Boston, who was not involved in the study.
The pros and cons of genetic engineering

Those who support such practices argue that genetically engineering human embryos can help eradicate all sorts of devastating diseases that are due to an individual's faulty DNA and that cannot be treated or cured in any other way than by doing away with the genes that cause them.

Then again, others argue that genetic modifications done to human embryos are bound to propagate to future generations and can end up birthing an entirely new generation of genetic diseases. Besides, there are ethical hurdles that come with editing a human embryo's DNA

From: http://news.softpedia.com/news/World-First-Scientists-Genetically-Modify-Lab-Made-Human-Embryos-479145.shtml

[humble3d]

We'll bet there is far more than they are telling...

Scientists edited the genomes of human embryos

Media and more via the link below...

In March, a rumor surfaced in the scientific community that was intriguing, and perhaps a bit chilling: According to those in the know, researchers in China had successfully edited the genomes of human embryos, altering their DNA in a way never accomplished in our own species. MIT Technology Review reported on the murmurings that someone had altered the germ line -- the genetic information that come together and form something new when eggs and sperm collide. Even unconfirmed, those rumors led to a lot of debate about the potential downsides of altering the germ line. Carl Zimmer has more on the controversy at his blog on National Geographic.

But it turns out the rumors are true.

On Wednesday, Nature News reported that the paper in question had been quietly published in a low-profile journal called Protein & Cell.

But no, you can't expect to see any genetically altered humans running around in the coming months, for better or for worse. From MIT Technology Review:

The team did not try to establish a pregnancy and say for ethical reasons they did their tests only in embryos that were abnormal.

“These authors did a very good job pointing out the challenges,” says Dieter Egli, a researcher at the New York Stem Cell Foundation in Manhattan. “They say themselves this type of technology is not ready for any kind of application.”

The work, led by Junjiu Huang of Sun Yat-sen University in Guangzhou, focused on modifying the gene responsible for ß-thalassaemia, a blood disorder that can be fatal. They used CRISPR, a cutting-edge gene editing tool that's already made serious waves in the genome editing of other species. By going after genes at the earliest stage of human development -- in a single-celled embryo -- theoretically one can make sure all the subsequent copies of the gene are the superior version.

But we have a long way to go before that's actually the case. From Nature News:

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.”

Indeed, not all of the embryos that successfully received the new gene had it throughout all of their cells. Many were mosaics, with some good copies of the gene and some bad ones. Carl Zimmer points out that this could end really badly: If a doctor tested the potential embryos of a couple looking to edit out a deadly gene mutation, they might take a cell sample that showed the embryo as having the healthy gene. If it was a mosaic, the resulting baby might in fact have enough copies of the bad gene to cause problems.

And in some of the embryos, the gene editing caused unintended mutations in other genes.

"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," George Daley, a stem-cell biologist at Harvard Medical School, told Nature. "Their study should be a stern warning to any practitioner who thinks the technology is ready for testing to eradicate disease genes."

So it's an exciting first step, but nothing more. Science has a long way to go before this is something we can do on embryos intended for implantation, and some are already trying to discourage researchers from taking the next steps toward that goal. Even the study authors themselves are incredibly cautious about their findings, firmly reporting that the technique is far from ready.

But you can be sure that such a caveat won't stop a lot of hoopla about the pros and cons of "designer babies."

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http://www.washingtonpost.com/news/speaking-of-science/wp/2015/04/22/the-rumors-were-true-scientists-edited-the-genomes-of-human-embryos-for-the-first-time/?tid=pm_national_pop_b

http://www.nature.com/news/chinese-scientists-genetically-modify-human-embryos-1.17378