| bioproject id |
PRJNA605208
to NCBI
|
| key word |
light;RNA-seq, Mexican tetra, troglomorphy, regressive evolution |
| experiment type |
light |
| publication |
Sears, Connor R. , T. E. Boggs , and J. B. Gross . "Dark‐rearing uncovers novel gene expression patterns in an obligate caveヾwelling fish." Journal of Experimental Zoology Part B: Molecular and Developmental Evolution(2020). |
| description |
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. |
| abstract |
Extreme environments often result in the evolution of dramatic adaptive features. The Mexican tetra, Astyanax mexicanus, includes 30 different populations of cave-dwelling forms that live in perpetual darkness. As a consequence, many populations have evolved eye loss, reduced pigmentation, and amplification of non-visual sensory systems. Closely-related surface-dwelling morphs demonstrate typical vision, pigmentation, and sensation. Transcriptomic assessments in this system have revealed important developmental changes associated with the cave morph, however they have not accounted for photic rearing conditions. Prior studies reared individuals under a 12:12 hr light/dark (LD) cycle. Here, we reared cavefish under constant darkness (DD) for 5+ years. From these experimental individuals, we performed mRNA sequencing and compared gene expression of surface fish reared under LD conditions to cavefish reared under DD conditions to identify photic-dependent gene expression differences. GO enrichment analyses revealed a number of previously underappreciated cave-associated changes impacting blood physiology and olfaction. We further evaluated the position of differentially expressed genes relative to QTL positions from prior studies, and found several candidate genes associated with these ecologically relevant lighting conditions. In sum, this work highlights photic condition as a key environmental factor impacting gene expression patterns in blind cave-dwelling fish. |
Gene
RNA