稀有鮈鲫Ras信号通路相关基因的克隆、序列分析及其组织分布

Ras基因是一类在生物进化过程中较为保守的原癌基因,在多种细胞生命活动中起到细胞增殖、分化和细胞骨架构建等重要作用。本文克隆了稀有鮈鲫Ras信号通路相关的k-ras、n-ras、pik3cd、pin1和raf1基因的部分c DNA片段,并分析了其序列。序列分析结果表明,k-ras的氨基酸序列与鲤鱼相对应的氨基酸序列同源性最高,为99%;n-ras、pik3cd、pin1和raf1的氨基酸序列均与斑马鱼相对应的氨基酸序列同源性最高,分别为99%、87%、96%和97%,结果表明稀有鮈鲫与鲤鱼、斑马鱼的亲缘关系较近。组织表达分析表明,k-ras、n-ras、pik3cd、pin1和raf1基因在肝脏、鳃、肾脏、脑和性腺等组织中具有表达差异性。本文为研究环境污染物对鱼类致癌作用机制和安全性评估提供分子生物学基础和科学依据。

Clone, Sequence Analysis and Distribution of Ras Pathway Genes in Rare Minnow

Ras gene is a kind of more conservative proto-oncogenes in the process of evolution, it is very important for cell proliferation and differentiation, and the construction of cytoskeleton. Partial cDNA sequences of k-ras, n-ras, pik3cd, raf1 and pin1, which are involved in Ras signal pathway, were cloned and sequenced from the liver of Gobiocypris rasus. Sequence analysis showed that the k-ras gene shared the highest sequence affinity with the amino acid sequence of Cyprinus carpio (99%), whereas the other four genes showed the highest sequence affinity with those of Danio rerio (99%, 87%, 96% and 97%, respectively). The phylogenetic trees were developed based on amino acid sequences of Gobiocypris rarus and other known species, which showed the closest genetic relationship with Gobiocypris rarus, Cyprinus carpio and Danio rerio. Besides, differential gene expression of k-ras, n-ras, pik3cd, raf1 and pin1 has been demonstrated across a panel of tissues in the rare minnow. It has been shown that all the genes had differential expression in liver, gill, kidney, brain and gonad. The present study offered scientific information for discovering cancer processes and assessing ecological health risk of aquatic xenobiotics of Gobiocypris rarus at molecular level.