Expression and regulation of in spotted scat ().

is an isoform of the eukaryotic translation elongation factor 1 A (eEF1A) and is vital for fish ovarian development. Spotted scat () is a popular marine cultured fish species in Southern Asia and China, and its artificial reproduction is complicated, with a relatively low success ratio in practice. In this study, the gene was cloned from spotted scat. Tissue distribution analysis showed that was mainly expressed in the ovary. qRT-PCR showed that expression levels gradually decreased insignificantly in the ovaries from phase II to IV. Western blot analysis showed that was highly expressed in the ovary, while it was almost undetectable in the testis. Immunohistochemistry analysis stained mainly in the cytoplasm of the previtellogenic oocytes in ovaries of normal XX-female and sex-reversed XY-female. Aside from fish and amphibians, was also identified in some reptile species using genomic database searching. Analyses of the transcriptome data from four different fish species (Hainan medaka (), silver sillago (), Nile tilapia (), and Hong Kong catfish ()) revealed ovaries biased expression of in all, similar to spotted scat. While the neighbor genes of did not show ovary biased expression in the fish species analyzed. Bisulfite Sequencing PCR (BSP) results showed that the DNA methylation level of promoter was low in ovaries, testes, and muscles. The luciferase reporter assay demonstrated that activated expression in the presence of or . These results suggest that may be involved in regulating the early phase oocytes development of spotted scat.