WASHINGTON (AFP) – A team of scientists at the University of Georgia has successfully performed gene-editing on reptiles for the first time, creating a pair of albino lizards the size of a human index finger.
In a paper describing the breakthrough in the journal Cell Press on Tuesday, the researchers said it could help us better understand vision problems in humans with albinism. The powerful gene-editing technology known as CRISPR has led to big breakthroughs in mice, plants and humans, but getting it to work on reptiles had proved impossible because of key reproductive differences.
“For quite some time we’ve been wrestling with how to modify reptile genomes and manipulate genes in reptiles, but we’ve been stuck in the mode of how gene editing is being done in the major model systems” said Doug Menke, co-author of a paper that described the work in Cell Press on Tuesday.
By contrast, gene-editing techniques have been researched extensively on so-called “major model systems” like mice, chicken, and certain species of fish and frogs.
CRISPR gene-editing is usually performed on freshly fertilised eggs or single-cell zygotes, but the technique is difficult to apply to egg-laying animals. If you try to do it after fertilisation, millions of cells will have already grown, and trying to penetrate the leathery, flexible shell at that stage may kill the embryo, Menke told AFP.
The alternative is to perform the technique before fertilisation. Not only did it work, but, to their surprise, the gene-edits ended up in both the maternal-line and paternal DNA, not just the former as they had predicted.
But why did they choose to make the lizards albino?
The most obvious reason, said Menke, was to prove their technique had been successful, “If we see an albino lizard, it’s really obvious that it’s worked.”