Cao Yunpeng, Wang Haili, Jin Ping, Ma Fei, Zhou Xue
School of Chemistry and Biological Engineering, Nanjing Normal University Taizhou College, Taizhou 225300, China.
Laboratory for Comparative Genomics and Bioinformatics & Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210046, China.
Animals (Basel). 2023 Jul 4;13(13):2193. doi: 10.3390/ani13132193.
Low-density lipoprotein receptors (LDLRs) are a class of cell-surface endocytosis receptors that are mainly involved in cholesterol homeostasis and cellular signal transduction. Very-low-density lipoprotein receptors (VLDLRs), which are members of the LDLR family, have been regarded as multi-function receptors that fulfill diverse physiological functions. However, no gene has been identified in protochordates to date. As a representative protochordate species, amphioxi are the best available example of vertebrate ancestors. Identifying and characterizing the gene in amphioxi has high importance for exploring the evolutionary process of the LDLR family. With this study, a new amphioxus gene (designated ) was cloned and characterized using RACE-PCR. The 3217 nt transcript of the had a 2577 nt ORF, and the deduced 858 amino acids were highly conserved within vertebrate VLDLRs according to their primary structure and three-dimensional structure, both of which contained five characteristic domains. In contrast to other vertebrate VLDLRs, which had a conserved genomic structure organization with 19 exons and 18 introns, the had 13 exons and 12 introns. The results of a selective pressure analysis showed that the had numerous positive selection sites. Furthermore, the tissue expression of using RT-qPCR showed that RNA expression levels were highest in the gills and muscles, moderate in the hepatic cecum and gonads, and lowest in the intestines. The results of the evolutionary analysis demonstrated that the gene is a new member of the VLDLR family whose family members have experienced duplications and deletions over the evolutionary process. These results imply that the functions of LDLR family members have also undergone differentiation. In summary, we found a new gene homolog () in amphioxi. Our results provide insight into the function and evolution of the gene family.
低密度脂蛋白受体（LDLRs）是一类细胞表面内吞受体，主要参与胆固醇稳态和细胞信号转导。极低密度脂蛋白受体（VLDLRs）是LDLR家族的成员，被认为是具有多种生理功能的多功能受体。然而，迄今为止在原索动物中尚未鉴定出相关基因。文昌鱼作为原索动物的代表性物种，是脊椎动物祖先的最佳现存实例。在文昌鱼中鉴定和表征该基因对于探索LDLR家族的进化过程具有重要意义。通过本研究，利用RACE-PCR克隆并表征了一个新的文昌鱼基因（命名为 ）。该基因的3217 nt转录本具有2577 nt的开放阅读框（ORF），根据其一级结构和三维结构推导的858个氨基酸在脊椎动物VLDLRs中高度保守，二者均包含五个特征结构域。与其他具有19个外显子和18个内含子的保守基因组结构组织的脊椎动物VLDLRs不同，该基因有13个外显子和12个内含子。选择性压力分析结果表明，该基因有许多正选择位点。此外，利用RT-qPCR对该基因的组织表达分析表明，其RNA表达水平在鳃和肌肉中最高，在肝盲囊和性腺中中等，在肠道中最低。进化分析结果表明，该基因是VLDLR家族的一个新成员，其家族成员在进化过程中经历了重复和缺失。这些结果意味着LDLR家族成员的功能也发生了分化。总之，我们在文昌鱼中发现了一个新的基因同源物（ ）。我们的结果为该基因家族的功能和进化提供了见解。
Zotero 插件
