五氯酚暴露诱导斑马鱼胚胎细胞凋亡相关基因的变化及caspase-2基因克隆和系统进化分析

应用基因芯片技术研究发现,暴露于五氯酚的斑马鱼胚胎中有14个涉及细胞凋亡行为的基因表达发生了显著改变.利用生物信息学方法构建这些功能基因系统进化树,分析与环境毒物诱导的细胞凋亡行为密切相关的caspase-2基因和其他基因之间的同源关系.斑马鱼caspase-2基因由10个外显子和9个内含子组成,cDNA长1308bp,含一个开放阅读框(ORF),编码435个氨基酸.6种脊椎动物Caspase-2氨基酸序列的保守性及系统进化分析结果表明,在特定功能区结构域中氨基酸序列表现出较高的同源性,Caspase-2在进化上高度保守.利用RT-PCR技术,斑马鱼caspase-2基因cDNA被克隆并确认.研究结果表明斑马鱼caspase-2基因是一个研究细胞凋亡行为的模型分子,可为环境化合物的分子毒性评价及其机制研究提供一种分子标记。

Expression Changes of Apoptosis Related Genes after Pentachlorophenol Exposure and Molecular Cloning and Phylogenetic Analysis of caspase-2 in Zebrafish

Employing microarray analysis, we found that 14 apoptosis related genes including caspase-2 changed their expressions after pentachlorophenol exposure to zebrafish embryos. Using bioinformatics, we modeled the phylogenetic tree of these functional genes and made phylogenetic analysis on caspase-2 gene, related to apoptosis induced by toxicants. Zebrafish caspase-2 comprises 10 exons and 9 introns. The caspase-2 cDNA is 1308bp long and contains an open reading frame predicted to encode a protein with 435 amino acids. Protein sequence alignments and phylogenetic analysis among 6 vertebrates showed Caspase-2 proetein is highly conserved during evolution. Performing RT-PCR, zebrafish caspase-2 cDNA was cloned and confirmed. Taken together, our results indicated that zebrafish caspase-2 gene could be used as a model molecular to evaluate the effect of toxicants on apoptosis.