Cloning and expression of ASDIGIRR and ASTRAF6 genes of Acipenser sinensis

Acipenser sinensis is one of the ancient and rare fishes in China between teleost fish and cartilaginous fish, but it is vulnerable to different diseases in the process of artificial reproduction and culture, so it is necessary to deeply study the immune regulation of A. sinensis to provide theoretical basis for its prevention of diseases. A single Ig-IL-1R-related molecule (SIGIRR) and tumor necrosis factor receptor-associated factor 6 (TRAF6) are two important signal transduction elements in the signal transduction pathway of toll-like receptors. In this study, homologues of SIGIRR and TRAF6 of A. sinensis, named ASDIGIRR and ASTRAF6, were identified, and their expression levels in normal tissues and Poly (I:C) induced expression were investigated. Results show that ASDIGIRR and ASTRAF6 were expressed in 10 tissues of healthy sturgeon, and the highest expression was found in intestinal tract and head kidney, respectively. After incubating A. sinensis spleen cells with Poly(I:C), the expression of ASDIGIRR was significantly down-regulated at 3 h, and returned to the normal level at 6 h, then increased to the highest level at 24 h and then decreased, and at 48 h still higher than the control group. While the expression of ASTRAF6 reached the highest level at 6 h, and maintained till 24 h, then decreased to the lowest level at 48 h. The results show that ASDIGIRR and ASTRAF6 play an important role in the immune defense of A. sinensis against pathogen invasion.