Blind Cave Fish May Shed Light on Human Eye Diseases

Blind cave fish may just shed some light on eye disease and other human health issues. Scientists have examined these tiny eyeless fish and have found clues about the underpinnings of degenerative eyes disease and other issues.

Cave fish actually exhibit repeated, independent evolution for a variety of traits, including eye degeneration, pigment loss, increased size, number of taste buds and shifts in behavior. All of these traits make sense when the animal is living within the dark and cold recesses of a cave pool. In order to better understand how this fish adapt to their cave environments, the scientists conducted the first-ever de novo genome assembly for a species of blind cave fish called Astyanax mexicanus.

"The cavefish genome sequence is similar to the human genome sequence, and we share many of the same pathways and genes with them," said Suzanne Mcgaugh, the lead researcher, in a news release.

 "They're an ideal subject for study, because they have traits that are directly translatable to human health."

More specifically, the scientists identified repeat elements in the genome of the cavefish and compared them to those in similar species. In the end, they found specific genes for potential functional and expression differences. Not only that, but they were able to generate a list of candidate genes for hallmark cave fish traits, which could advance understanding of human eye disease.

"Many of those traits are really important for human health, such as the fishes' eye loss, which could be analogous to human diseases such as retinal degeneration," said McGaugh. "There are three to five events in Mexico of the same species going into caves and evolving these traits. So we're hoping to see if it replays the same way, and discover if there is anything consistent about the genes and where genetic changes occur."

The findings are published in the journal Nature Communications.