American researchers using CRISPR-Cas9 knockout (“off”) of the squid Doryteuthis pealeii gene tryptophan 2,3-dioxygenase of whose activity is normal leads to the formation of pigments, reported in Current Biology. Genes of cephalopods, scientists are not modified. The percentage of successful knockout was very high, and this means that the method has good application prospects.
Cephalopods — squid, cuttlefish, and to a lesser degree octopus — it is now increasingly used as model animals, as do mice and rats. However, in the case of rodents experience and capabilities of the scientists is still more: there are a lot of lines (“rocks”) mice whose genes are modified for specific research needs, and transgenic cephalopod has never been done. Meanwhile, Sami squid can easily change the work of their own genetic material: they are able to edit their RNA in the nucleus, and beyond, and due to this, in fact, encode a single gene, several different composition of proteins.
Joshua Rosenthal (Joshua Rosenthal) and his colleagues from the marine biology Lab of the University of Chicago tried to change the DNA cephalopod mollusk with the help of CRISPR-Cas9. In an experimental animal, they chose the squid Doryteuthis pealeii is a well — studied view, convenient for the fact that there is a method of artificial insemination, and the embryos are nearly transparent.
Decided to knock out a gene whose deactivation, on the one hand, it will be clearly seen in these organisms and, on the other hand, will not lead to life-threatening consequences. This gene tdo — tryptophan-2,3-dioxygenase of theenzyme, which in invertebrates is beginning the transformation of tryptophan into the pigments of the body. Accordingly, if the tdo will not work, squid will grow colorless.