Genetic modification of course is a contentious topic, nonetheless, scientists have been doing it for years, and with great success. Researchers can meticulously chop and redesign genes in microbes, human cells, plants and even animal embryos. It’s certainly a very vital technique, but at what stage should we draw the line on what is ethically acceptable? This is an endless debate among scientists as well as public, however, arguments were lately revived by the news that Chinese scientists are transmuting the genomes of human embryos. To read about this landmark study refer the journal Protein & Cell.
There are a number of reasons that refining human embryos is such a hotly argued subject. Firstly, the individual evidently cannot consent to the procedure, nevertheless if the embryo or succeeding human would not survive without it, then arguably this is not an issue. Flags have also been raised owing to probable unintended consequences that may not immediately be evident. Also, as Nature indicates, since the changes would be transferred to offspring, once again it is hard to foretell what effects they may have on future generations.
Nonetheless, those in favor of the procedure contend that it could offer a way to put an end to genetic diseases, like cystic fibrosis, Tay-Sachs and Huntington’s disease. With this concept in mind, researchers from Sun Yat-sen University in Guangzhou began probing the probability of reshaping the faulty gene responsible for a potentially fatal inherited blood disorder known as beta thalassemia, in which sufferers don’t produce sufficient hemoglobin, the molecule which carries oxygen round the body.
Researchers started by first collecting donor embryos from a fertility clinic that were non-viable, i.e. would not have survived to term. Despite the fact that these were intended for use in IVF, they ended up with excessive chromosomes as they were fertilized by multiple sperm, so they couldn’t have resulted in a live birth.
Next, they used a proven gene-editing technique called CRISPR/Cas9, which is a complex of bacterially-derived enzymes that behave like a pair of molecular scissors, explicitly binding to target stretches of DNA and cutting them out. Researchers injected these enzymes into 86 embryos; then they replaced the gaps with healthy genes and monitored their development.
Development of a few embryos stopped, nonetheless, the team chose 54 of the survivors and then tested them further to find out whether the editing had been successful. They discovered that the faulty gene, HBB, had been eliminated in barely 28 embryos, and just a few of these had the healthy replacement gene they tried to insert. Moreover, the enzymes also added in many mutations, indicating that the system is acting in an imprecise manner and is therefore not mature enough to be used, to eradicate diseases at this stage. Nevertheless, the researchers are not put off by this setback, and plan to carry on their work in order to improve the technique.