In a world first, scientists have created a gene-edited albino reptile that could help cure eye conditions in humans.
The lizard, roughly the size of an index finger, has been created as humans with albinism often have vision problems, and so scientists hope to use them as a model to study how the loss of the relevant gene impacts retina development.
Scientists created the reptile using a technique that had previously been thought impossible to use on reptiles because it requires reagents – substances used to spark chemical reactions – to be injected directly into newly fertilised eggs.
Lizard eggs fertilise inside the body at unpredictable times, which meant researchers faced an unprecedented challenge to successfully adapt the established CRISPR-Cas9 gene-editing process.
University of Georgia professor Doug Menke and his research team identified a solution when they noticed that the membrane covering a lizard’s ovary is transparent, allowing them to see all of the developing eggs and work out which were next to be fertilised.
Reagents were injected into the eggs waiting to be fertilised and after a three-month wait for the baby lizards to hatch, the operation proved successful.
Writing in the journal Cell Reports, Mr Menke said: “We had to wait three months for the lizards to hatch, so it’s a bit like slow-motion gene editing. But it turns out that when we did this procedure, about half of the mutant lizards that we generated had gene-editing events on the maternal allele and the paternal allele.”
The results suggested that the reagents remained active for several days or even weeks within the unfertilised eggs, with between 6% and 9% of cells in the ovary producing offspring with signs of gene-editing.
Mr Menke added: “Relative to the very established model systems that can have efficiencies up to 80% or higher, 6% seems low, but no one has been able to do these sorts of manipulations in any reptile before.
“There’s not a large community of developmental geneticists that are studying reptiles, so we’re hoping to tap into exciting functional biology that has been unexplored.”
Looking further ahead, the gene-editing technique could also be translated for use in other animals.
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