Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) are multifunctional adaptor proteins in the immune system, which play significant roles in the regulation of Toll-like receptor and RIG-I-like receptor signaling pathway in animals. Although many TRAF genes have been identified in mollusks, the systematic identification of the TRAF gene family in noble scallop Chlamys nobilis has not been reported, and very little is known about its roles in scallop innate immunity. In this study, four TRAF genes (CnTRAF 2, CnTRAF3, CnTRAF4 and CnTRAF6) were identified and characterized from C. nobilis. Sequence and phylogenetic analysis revealed that CnTRAFs contain typical conserved domains closely related to TRAFs of other mollusks. The motifs analysis of C. nobilis CnTRAFs also showed that the conserved motifs were identical to other mollusks and vertebrates. The expression pattern of CnTRAF genes in tissues of brown and golden scallops (the carotenoid content of golden scallops is significantly higher than that of brown scallops) were not statistically significant, but in hemolymph of scallops challenged with bacteria, the expression of CnTRAF genes was significantly higher than that of control, suggesting that the CnTRAF genes play vital roles in the immunity of mollusks. Furthermore, at several time points after bacteria challenge, the expression level of CnTRAF genes in golden scallops were significantly higher than that of brown scallops, indicating that carotenoids may enhance CnTRAF genes expression and immunity. The systematic analysis of the roles of TRAFs in C. nobilis provides valuable information for the further researches of CnTRAF genes.

肿瘤坏死因子（TNF）受体相关因子（TRAF）是免疫系统中的多功能衔接蛋白，在动物中Toll样受体和RIG-I样受体信号通路的调节中起着重要作用。尽管已在软体动物中鉴定出许多TRAF基因，但尚未报道系统地鉴定高贵扇贝Chlamys nobilis中TRAF基因家族，对其在扇贝先天免疫中的作用知之甚少。在这项研究中，鉴定了四个TRAF基因（CnTRAF 2，CnTRAF3，CnTRAF4和CnTRAF6），并从C. nobilis中鉴定出其特征。序列和系统发育分析表明，CnTRAF包含与其他软体动物的TRAF紧密相关的典型保守域。的基序分析C.扇贝CnTRAFs还显示保守的基序与其他软体动物和脊椎动物相同。CnTRAF基因在棕色和金色扇贝组织中的表达模式（金色扇贝的类胡萝卜素含量显着高于棕色扇贝）在统计学上无统计学意义，但在受细菌攻击的扇贝的血淋巴中，CnTRAF基因的表达显着高于对照组，表明CnTRAF基因在软体动物的免疫中起着至关重要的作用。此外，在细菌攻击后的几个时间点，金扇贝中CnTRAF基因的表达水平显着高于棕扇贝，表明类胡萝卜素可以增强CnTRAF基因的表达和免疫力。对TRAFs在其中的作用的系统分析C.扇贝提供CnTRAF基因的进一步研究的有价值的信息。