Wang Xia, Qu Xiaoxu, Lu Xia, Chen Min, Ning Junhao, Liu Haijun, Liu Guilong, Xu Xin, Zhang Xiaotong, Yu Kai, Xu He, Liu Bo, Wang Chunde
College of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong, 266109, China.
Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, 264003, China.
Fish Shellfish Immunol. 2023 Apr;135:108675. doi: 10.1016/j.fsi.2023.108675. Epub 2023 Mar 9.
The tumor necrosis factor receptor-related factor (TRAF) family has been reported to be involved in many immune pathways, such as TNFR, TLR, NLR, and RLR in animals. However, little is known about the roles of TRAF genes in the innate immune of Argopecten scallops. In this study, we first identified five TRAF genes, including TRAF, TRAF, TRAF, TRAF and TRAF, but not TRAF and TRAF, from both the bay scallop A. irradians (Air) and the Peruvian scallop A. purpuratus (Apu). The phylogenetic analysis showed that the TRAF genes in Argopecten scallops (AiTRAF) belong to the branch of molluscan TRAF family, which lacks TRAF and TRAF. Since TRAF is a key bridge factor in the tumor necrosis factor superfamily and plays an important role in innate and adaptive immunity, we cloned the ORFs of the TRAF gene in both A. irradians and A. purpuratus, as well as in two reciprocal hybrids (Aip for the hybrid Air × Apu and Api for the hybrid Apu × Air). Differences in conformational and post-translational modification resulted from the variation in amino acid sequences may cause differences in activity among them. Analysis of conserved motifs and protein structural domains revealed that AiTRAF contains typical structural domains similar to those of other mollusks and has the same conserved motifs. Tissue expression of TRAF in Argopecten scallops challenged by Vibrio anguillarum was examined by qRT-PCR. The results showed that AiTRAF were higher in gill and hepatopancreas. When challenged by Vibrio anguillarum, the expression of AiTRAF was significantly increased compared with the control group, indicating that AiTRAF may play an important role in the immunity of scallops. In addition, the expression of TRAF was higher in Api and Aip than in Air when challenged by Vibrio anguillarum, suggesting that TRAF may have contributed to the high resistance of Api and Aip to Vibrio anguillarum. The results of this study may provide new insights into the evolution and function of TRAF genes in bivalves and ultimately benefit scallop breeding.
据报道，肿瘤坏死因子受体相关因子（TRAF）家族参与动物体内许多免疫途径，如TNFR、TLR、NLR和RLR等。然而，关于TRAF基因在海湾扇贝先天免疫中的作用却知之甚少。在本研究中，我们首先从海湾扇贝（A. irradians，简称Air）和秘鲁扇贝（A. purpuratus，简称Apu）中鉴定出五个TRAF基因，分别为TRAF、TRAF、TRAF、TRAF和TRAF，但未鉴定出TRAF和TRAF。系统发育分析表明，海湾扇贝中的TRAF基因（AiTRAF）属于软体动物TRAF家族的分支，该分支缺少TRAF和TRAF。由于TRAF是肿瘤坏死因子超家族中的关键桥梁因子，在先天免疫和适应性免疫中发挥重要作用，我们克隆了海湾扇贝和秘鲁扇贝中TRAF基因的开放阅读框（ORF），以及两个正反交杂种（Air×Apu的杂种Aip和Apu×Air的杂种Api）中TRAF基因的开放阅读框。氨基酸序列的差异导致的构象和翻译后修饰的差异可能会使它们之间的活性产生差异。对保守基序和蛋白质结构域的分析表明，AiTRAF含有与其他软体动物相似的典型结构域，并且具有相同的保守基序。通过qRT-PCR检测了鳗弧菌攻击后海湾扇贝中TRAF的组织表达情况。结果表明，AiTRAF在鳃和肝胰腺中的表达较高。当受到鳗弧菌攻击时，AiTRAF的表达与对照组相比显著增加，表明AiTRAF可能在扇贝免疫中发挥重要作用。此外，在受到鳗弧菌攻击时，Api和Aip中TRAF的表达高于Air，这表明TRAF可能有助于Api和Aip对鳗弧菌具有较高的抗性。本研究结果可能为双壳贝类中TRAF基因的进化和功能提供新的见解，并最终有利于扇贝育种。
