College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Fish Shellfish Immunol. 2021 Dec;119:613-622. doi: 10.1016/j.fsi.2021.10.041. Epub 2021 Nov 3.
Fibrinogen-related proteins (FREPs) are distributed universally in vertebrates and invertebrates. These proteins contain fibrinogen-like (FBG) domains in their C-terminal region and involve in immune responses and other aspects of physiology in invertebrates. In this study, 54 proteins that contain FBG domains or a fibrinogen_c domain were identified in Haliotis discus hannai. Comparatively, 88 and 63 FREPs were identified from the genomes of H. rufescens and H. laevigata. Most FREPs of abalones had a conserved motif containing a bound calcium ion site and a second conserved motif containing a polymerization pocket site. By sequence analysis, 394 SNPs and 11 Indels were identified in 20 FREP genes of the whole genome of H. discus hannai; 992 SNPs and 42 Indels were found in 64 FREPs of H. rufescens, and 192 SNPs and 12 Indels were found in 21 FREPs of H. laevigata. Among these SNPs, 92 missense mutation sites were identified in 26 FREP genes of H. rufescens, and 12 were identified in 8 FREP genes of H. laevigata. Due to the poor genomic integrity, annotations of the SNPs or Indels in H. discus hannai did not yield missense mutant sites. FREP genes with polymorphisms were ubiquitously expressed in all the tested tissues; however, the expression is lowest in the hemolymph. In response to Vibrio parahemolyticus infection, expression of FREP genes was significantly upregulated at different exposure times in gills, hepatopancreas, and hemolymph in H. discus hannai. Overall, this study documented the FREP genes of abalones and shed light on the role of FREPs in the innate immune system of these aquaculture species for the prevention and control of diseases.
纤维蛋白原相关蛋白（FREP）在脊椎动物和无脊椎动物中普遍存在。这些蛋白在 C 端区域含有纤维蛋白原样（FBG）结构域，参与无脊椎动物的免疫反应和其他生理过程。在这项研究中，在皱纹盘鲍（Haliotis discus hannai）中鉴定出 54 种含有 FBG 结构域或纤维蛋白原_c 结构域的蛋白。相比之下，在红鲍（H. rufescens）和杂色鲍（H. laevigata）的基因组中分别鉴定出 88 种和 63 种 FREP。鲍类的大多数 FREP 都具有一个保守基序，包含一个结合钙离子的位点和另一个包含聚合口袋的位点。通过序列分析，在皱纹盘鲍的全基因组 20 个 FREP 基因中鉴定出 394 个 SNP 和 11 个插入缺失；在红鲍的 64 个 FREP 中发现了 992 个 SNP 和 42 个插入缺失，在杂色鲍的 21 个 FREP 中发现了 192 个 SNP 和 12 个插入缺失。在这些 SNP 中，在红鲍的 26 个 FREP 基因中鉴定出 92 个错义突变位点，在 8 个 FREP 基因中鉴定出 12 个错义突变位点。由于基因组完整性较差，在皱纹盘鲍中，SNP 或插入缺失的注释并未产生错义突变位点。具有多态性的 FREP 基因在所有测试的组织中均广泛表达；然而，在血淋巴中表达量最低。在对副溶血弧菌感染的反应中，在皱纹盘鲍的鳃、肝胰腺和血淋巴中，不同暴露时间 FREP 基因的表达均显著上调。总体而言，本研究记录了鲍类的 FREP 基因，并揭示了 FREP 在这些水产养殖物种先天免疫系统中的作用，以预防和控制疾病。
