These results show that the independent evolution of retinal degeneration in cavefish can occur by different developmental genetic mechanisms. In contrast to the blind Mexican tetra cavefish Astyanax mexicanus, our results on morphologies and gene expression suggest that evolved retinal reduction in cave-dwelling Sinocyclocheilus occurs in a lens-independent fashion by the reduced proliferation and downregulation of transcriptional factors shown to have direct roles in retinal development and maintenance, including cone-rod homeobox (crx) and Wnt pathway members. Results from cave-dwelling Sinocyclocheilus revealed reduced transcription of phototransduction and other genes important for retinal function.
De novo transcriptome assemblies were developed for both species, and contigs were annotated with gene ontology.
