A calf was born with an edited gene on the X chromosome. Thanks to the intervention of genetic engineers from the University of California at Davis, part of the offspring of this bull, even with two female X chromosomes, will have the SRY gene, which determines sex according to the male type.
That is, for the first time, cows will be born that are completely identical to bulls. This is done to form a herd of all males. Thus, scientists are trying to achieve faster weight gain and production of more meat for animal husbandry.
However, upon closer inspection, it turned out that the insertion made by the scientists was not perfect. First, along with the SRY gene, fragments of the bacterial plasmid (which was used as the carrier of the SRY gene) and the jellyfish fluorescent protein gene (which made the embryo glow green) were also inserted in different places of the genome.
Secondly, the SRY gene itself was inserted several times, and two of them were inserted backwards. Such mistakes are still typical of the first experiments to create designer animals. Scientists are just starting to use the CRISPR / Cas9 genetic editor.
According to Russian scientists, the experiment once again confirms the premature intervention in the human embryo using CRISPR / Cas9.
“The main concern when using this method in the clinic is the high nonspecific activity of CRISPR / Cas9 in relation to other, non-target genes. However, this work shows that a high frequency of undesirable changes is also observed in the target locus (insertion of several gene copies, insertion of a gene in the reverse sequence, insertion of fragments of the plasmid backbone, unwanted insertion of random nucleotides), which can potentially lead to the development of various diseases, ”she explained. Izvestia, Head of the Genome Editing Laboratory at the N.P. Bochkova (FGBNU MGNTs) Svetlana Smirnikhina.
According to Konstantin Krutovsky, Professor of the Department of Genomics and Bioinformatics of the Siberian Federal University, Professor of the University of Göttingen (Germany), although, according to the experimenters, the mistakes did not cause side effects in the bull, in fact, there could be potentially serious consequences.
Read more in the exclusive material of Izvestia:
Progenitor bull: genetic engineers created Adam for the male herd