稀有鮈鲫细胞凋亡相关基因的克隆及序列分析

Cloning and Sequence Analysis of Genes Involved in Cell Apopotsis of Rare Minnow(Gobiocypris rasus)

细胞凋亡是调控机体发育和维护内环境稳定的重要机制。在克隆了稀有鮈鲫(Gobiocypris rarus)肝脏组织中凋亡相关的bcl-2、apaf-1、caspase-3和caspase-9基因的部分cDNA片段之后,进行了序列分析。结果表明,caspase-3和caspase-9基因片段与唐鱼(Tanichthys albonubes)相对应的核苷酸序列同源性最高,而bcl-2、apaf-1基因片段则分别与鮈鱼(Gobio gobio)和鲤鱼(Cyprinus carpio)相对应的核苷酸序列同源性最高,为99%和89%。基于稀有鮈鲫和已知物种的caspase-3基因核苷酸序列构建了系统发育树,发现稀有鮈鲫与唐鱼、斑马鱼(Danio rerio)的亲缘关系最近,而与金头鲷(Sparus aurata)、红鳍东方鲀(Takifugu rubripes)的亲缘关系较远。本研究为深入理解外源性化学物质对鱼类的毒理学机制及其生态健康风险评价提供科学数据,同时也为稀有鮈鲫在鲤科鱼类的分类及进化地位的研究提供分子水平的重要参考。

Apoptosis is important for regulating development and maintaining homeostasis of the organism.The partial cDNA sequences of bcl-2,apaf-1,caspase-3 and caspase-9,which are involved in cell apoptosis,were cloned and sequenced from the liver of Gobiocypris rasus.Sequence analysis showed that the caspase-3 and caspase-9 genes shared the highest sequence affinity with the nucleotide sequences of Tanichthys albonubes,whereas bcl-2 and apaf-1 genes showed the highest sequence affinity with those of Gobio gobio（99%） and Cyprinus carpio（89%）,respectively.The phylogenetic trees were developed based on the caspase-3 nucleotide sequences of Gobiocypris rarus and other known species,which showed the closest genetic relationship among Gobiocypris rarus,Tanichthys albonubes and Danio rerio,while Sparus aurata and Takifugu rubripes had a distant genetic relationship.The present study offered scientific information not only for discovering toxicological mechanism and assessing ecological health risk of aquatic xenobiotics,but also for classification and evolutionary status of Gobiocypris rarus at molecular level.