Abstract：
As a crucial member of pattern-recognition receptors (PRRs), the Tolls/Toll-like receptors (TLRs) gene family has been proven to be involved in innate immunity in crustaceans. In this study, nine members of TLR gene family were identified from the mud crab (Scylla paramamosain) transcriptome, and the structure and phylogeny of different SpTLRs were analyzed. It was found that different SpTLRs possessed three conserved structures in the TIR domain. Meanwhile, the expression patterns of different Sptlr genes in examined tissues detected by qRT-PCR had wide differences. Compared with other Sptlr genes, Sptlr-6 gene was significantly highly expressed in the hepatopancreas and less expressed in other tissues. Therefore, the function of Sptlr-6 was further investigated. The expression of the Sptlr-6 gene was up-regulated by Poly I: C, PGN stimulation and Vibrio parahaemolyticus infection. In addition, the silencing of Sptlr-6 in hepatopancreas mediated by RNAi technology resulted in the significant decrease of several conserved genes involved in innate immunity in mud crab after V. parahaemolyticus infection, including relish, myd88, dorsal, anti-lipopolysaccharide factor (ALF), anti-lipopolysaccharide factor 2 (ALF-2) and glycine-rich antimicrobial peptide (glyamp). This study provided new knowledge for the role of the Sptlr-6 gene in defense against V. parahaemolyticus infection in S. paramamosain.
摘要：
作为模式识别受体（PRR）的重要成员，Toll/Toll样受体（TLRs）基因家族已被证明与甲壳类动物的先天免疫有关。在这项研究中,从泥蟹（Scyllaparamamosain）转录组中鉴定出TLR基因家族的9个成员，并对不同SpTLRs的结构和系统发育进行了分析。发现不同的SpTLR在TIR结构域中具有三个保守结构。同时,qRT-PCR检测的不同Sptlr基因在受检组织中的表达模式存在很大差异。与其他Sptlr基因相比,Sptlr-6基因在肝胰腺中显著高表达,而在其它组织中表达较少。因此,进一步研究了Sptlr-6的功能。Sptlr-6基因的表达被PolyI：C上调，PGN刺激和副溶血性弧菌感染。此外,通过RNAi技术介导的肝胰腺中Sptlr-6的沉默导致副溶血性弧菌感染后泥蟹先天免疫中涉及的几个保守基因的显着减少，包括津津乐道，myd88背侧,抗脂多糖因子（ALF），抗脂多糖因子2（ALF-2）和富含甘氨酸的抗菌肽（glyamp）。这项研究为Sptlr-6基因在抗副溶血性弧菌感染中的作用提供了新的知识。
