Molecular cloning and characterization of p38 gene in the Chinese Mitten Crab, Eriocheir sinensis

p38 is an important component of the MAPK signaling pathways as a Ser/Thr protein kinase. We cloned the full length p38 (Es-p38) cDNA sequence in Eriocheir Sinensis which contained a 1098-nucleotide ORF that encoded a protein of 365 amino acids. Es-p38 protein has a p38 MAPK functional domain (STKc_p38), it is a typical serine/threonine kinase and processes all p38 protein's conservative T-G-Y motif. Tissue expression of the Es-p38 gene and expression during testis development stages were determined by quantitative real-time PCR analysis. The results show that Es-p38 gene is expressed in various tissues, but it expresses higher in the muscle, hepatopancreas, intestine, ovary and testis. The expression level of Es-p38 gene at different stages of testis development shows no significant difference between the spermatocyte phase (July-August) and spermatid stage (August-October), but it rises significantly in the mid-late period of sperm stage (December-January). This changing trend has a positive relationship with the E. Sinensis gonad development and reproduction stage, which preliminarily shows that Es-p38 may function in the E. Sinensis testis development and the process of spermatogenesis.