Cloning, characterisation and expression analysis of the HtTLR2 gene in Helice tientsinensis Rathbun, 1931
Toll-like receptors (TLRs) are important pattern recognition receptors involved in crustacean innate immunity. In this study, the full-length cDNA of HtTLR2 was cloned from the mudflat crab Helice tientsinensis using rapid amplification of cDNA ends (RACE). The HtTLR2 cDNA was 3854 bp in length and contained a 3036-bp open reading frame (ORF) encoding a 1011-amino-acid protein. Bioinformatics analysis showed that the HtTLR2 protein possessed conserved structural features typical of TLR family members. Phylogenetic analysis indicated that HtTLR2 was closely related to Toll2 from Eriocheir sinensis . Tissue distribution analysis revealed high HtTLR2 expression in the gills and hepatopancreas and its expression was significantly upregulated in both tissues following infection with Vibrio parahaemolyticus (Fujino et al., 1951) Sakazaki et al., 1963. This study provides new insights into the TLR gene family of H. tientsinensis and lays a foundation for further investigation of the immune mechanisms of this species.