Washington (AFP)
A team of scientists from the University of Georgia in the United States managed to publish the genome of reptiles for the first time thanks to the Crispr genetic scissors, creating mini-lizards albinos.
The manipulation could improve our understanding of sight problems in humans, hope the researchers.
"There are few approaches and methods to manipulate reptile embryos, unlike other species," says Doug Menke, co-author of the study published in the journal Cell Press on Tuesday.
The Crispr tool (Crispr-Cas9 by its full name) is widely used on mice, hens and some species of fish and frogs - it has even been used on humans during the controversial procedure used by a Chinese scientist to give birth to babies who are resistant to the HIV virus.
These genetic scissors are generally used on fertilized oocytes, but the technique is difficult to apply to animals that lay eggs.
In reptiles, it is difficult to know exactly when an egg is fertilized, because the female keeps the male's sperm for a relatively long time before fertilization. If you inject Crispr too early, you risk being spoiled. If it is done too late, the embryo will have grown too much and its membrane will have become too hard to be pierced without danger.
The researchers found that the transparent membrane of the ovaries allowed them to see the oocytes that were soon to be fertilized. They injected Crispr just before fertilization, and it worked.
But why did you choose to make albino lizards?
The first reason is obvious: "If we see an albino baby lizard, we know it worked," says Doug Menke.
Then, the suppression of the targeted tyrosinase gene causes albinism but without killing the animal.
Finally, these manipulations are of interest to researchers because humans with albinism often have vision problems. By working on lizards, they hope to learn how the gene affects the development of the retina.
"Every species has a lot to tell us, as long as we take the time to develop the right methods to modify genes," concludes Doug Menke.
© 2019 AFP