A Potential Role of the Translation Elongation Factor eef1a1 in Gonadal High-Temperature Perception in Chinese Tongue Sole ( Cynoglossus semilaevis ).

The eukaryotic translation elongation factor 1 alpha ( eef1a ) gene has a well-defined role in protein synthesis. However, its role in external temperature perception and internal sex differentiation and development is still unclear. In this study, eef1a1 was identified and functionally analyzed in Chinese tongue sole ( Cynoglossus semilaevis ). The eef1a1 cDNA, 1809 bp in length, had a 1386 bp open reading frame (ORF) that encoded a 461 amino acid polypeptide containing one EF-1_alpha domain. eef1a1 expression levels were investigated across different tissues and during gonadal development. In the gonad, eef1a1 showed a sexually dimorphic expression pattern with a statistically higher expression level in the ovary than in the testis from 6 months postfertilization to 3 years postfertilization. Under high temperature (28 °C) treatment during C. semilaevis sex differentiation (from 30 days postfertilization to 3 months postfertilization), eef1a1 was statistically down-regulated in males, while the difference was not detected in females. In addition, the dual-luciferase assay exhibited that eef1a1 can respond to high temperature rapidly. Based on these results, C. semilaevis eef1a1 might have a dual role in the perception of external temperature changes and sex differentiation regulation.