Abstract
Sturgeons are representatives of non-teleost fishes. Genomes of fishes in general have been modified by series of whole genome duplications (WGDs) and there have been at least three WGD events during the sturgeon evolution.
Such changes strongly affected the evolution of sturgeon genomes, including the evolution of opsin genes. These genes encode opsine proteins, which are responsible for light detection.
This study is focused mainly on the identification of opsin genes and the level of their expression. We found that one species, the Starry sturgeon (Acipenser stellatus) is particulary interesting, since this species does not express any rod opsins and seems to rely only on the cone opsin genes.
All the other tested sturgeon species have both rods and cones in the retina. We further tested this phenomenon by the application of FISH (fluorescence in situ hybridization) and the distribution of photoreceptor cell types (rods/cones and their subtypes) is mapped.
We have specifically focused on the interspecific hybrids with different WDG history and ecological preferences. We present results in opsin gene expression profiles of the Sterlet (A. ruthenus) and the Siberian sturgeon (A. baerii), their hybrids, normoploids and specimes with manipulated ploidy level, and, lastly, between pigmented and albino specimens.