Now you see it, now you don’t

The Mexican cavefish (Astyanax mexicanus) occurs in two distinct forms. A sighted version lives in open streams, and a blind – indeed, eyeless – version inhabits caves.

Researchers at the US National Institutes of Health (NIH) have now discovered that the blind cave fish embryos start to develop eyes, but the process is shut off by the epigenetic silencing of vision-related genes.

Moe than two dozen of the affected genes are also found in humans, with many of them implicated in eye disorders. Scientists led by William Jeffery from the US University of Maryland are now studying the cave fish for clue that might lead to new treatments.

Their research is published in the journal Nature Ecology & Evolution.