The powerful CRISPR genome editor is not as powerful in newts and snakes: It has never been used to mean these embryos and reptiles. Researchers have now found a worker – by editing immature eggs, unfertilised with brown newts.
Researchers usually edit with CRISPR by spraying it into an egg to fertilize one cell, creating a DNA change that is present in each subsequent cell. But female fungi are a particular challenge: They store sperm in their evidence for long periods, making it difficult to timing the introduction of CRISPR to fertilization. They also form an egg shell when fertilized, and it is very difficult to place a needle at that time without damaging the embryo.
Instead, researchers from the University of Georgia (UGA) in Athens smashed the CRISPR complex into immature eggs in the ovaries, targeting a gene producing tyrosinase, an enzyme affecting pigmentation. After changing 146 immature eggs from 21 newts, the scientists got their rebate: four albino offspring, they report in a pre-edition posted this week on bioRxiv. To produce the change in color, mother and father genes must have mutated, making the researchers suspect that CRISPR has meant the egg genes and then stuck from around, disturbing the father 's genes after fertilization.
The new technique, which the scientists say is likely to work in many other lizard and snake species, is “a game singer,” dictating Tony Gamble, an evolutionary biologist studying geckos in Wales. University of Marquette in Milwaukee, Wisconsin. Douglas Menke of UGA, the developmental mouse geneticist who led the experiment, was more than a point: “The whole field of developmental genetics has left reptiles in the dust.” So far.