Dark-rearing uncovers novel gene expression patterns in an obligate cave-dwelling fish.

This study examines whole genome expression of surface and cave morphotypes of Astyanax mexicanus reared under different photic conditions. A subset of both cavefish and surface fish were reared under a 12 hour light dark cycle and separate subsets of both cavefish and surface fish were reared under 24 darkness - restoring the natural photic condition of the cave. RNA sequencing was performed after 5 years of rearing under either light:dark or dark:dark rearing.