American and Chinese scientists have found a way to get rid of endogenous retroviruses of pigs, the main barriers to transplantation of animal organs to man. For this purpose, they used the CRISPR technology. Article researchers published in the journal Science.
Endogenous retroviruses (ERV) represent traces of ancient viral infections in the genome of animals and humans. They can cause infection to those people who in the future will be the transplantation of organs from specially bred pigs. Although experts do not know whether ERV pose a threat, scientists believe that it is necessary to find a way to remove endogenous DNA viruses of animals.
The study used a line of cells isolated from tissues of embryos of pigs. With the CRISPR system, scientists were able to remove the genes of ERV. Along with this, the biologists stimulated the growth of cells of special substances, achieving a survival part of them. Then the kernel of the latter were embedded in the eggs were allowed to develop into embryos before putting them in the uterus of the pig. Thus, scientists have found 37 piglets without endogenous retroviruses.
System CRISPR/Cas9 is used to change the nucleotide sequence of DNA. Cas9 is a protein that cuts double chain in a certain area (site). This place defines guide RNA (trnk), which binds to a specific site of recognition.
The pigs are usually called chimeras, in which there are cells of pigs and humans. Chimeras are any organism composed of genetically distinct cells.