嗜热四膜虫五个hsp70基因的表达分析  

Expression analysis of 5 hsp70 genes in Tetrahymena thermophila

作　　者：冯立芳[1,2] 畅悦[1,3] 袁冬霞[1] 缪炜[1] 

机构地区：[1]中国科学院水生生物研究所水生生物多样性与保护重点实验室,湖北武汉430072 [2]浙江工商大学食品与生物工程学院,浙江杭州310012 [3]中国科学院研究生院,北京100049

出　　处：《Zoological Research》2011年第3期267-276,共10页动物学研究（英文）

基　　金：中国科学院知识创新项目(KSCX2-EW-G-6-4);国家自然基金资助项目(31071993)

摘　　要：鉴定得到嗜热四膜虫13个含有完整保守结构域的hsp70基因,对其中5个高度相似且无内含子的hsp70基因进行表达分析。在37、39和41℃热激条件下,实时荧光定量PCR结果表明,hsp70-2基因对热激响应最敏感。在四膜虫生长、饥饿和接合生殖这3种生理或发育状态下,Microarray结果显示,hsp70-4基因恒定且高表达;在热激条件下,hsp70-4基因的表达水平随着温度的升高而略微增加,证实hsp70-4基因为热休克相关蛋白hsc70基因;克隆的hsp70-4基因全长2208bp,开放阅读框长1959bp,编码653个氨基酸。Microarray结果提示,hsp70-3可能参与四膜虫饥饿早期(0～12h)的耐受和接合生殖后期(6～10h)的新大小核形成,老大核凋亡等事件;hsp70-5可能参与四膜虫饥饿晚期(12～15h)的耐受和接合生殖早期(0～6h)的小核减数分裂、小核交换和原核(pronuclear)融合事件。Blast2GO分析表明,与hsp70-3和hsp70-5共表达的基因分别参与不同的生物学过程,进一步反映了hsp70-3和hsp70-5这两个基因在功能上是存在差异的。Thirteen hsp70 genes with complete conserved domains were identified in Tetrahymena thermophila,and expression of five similar and non-intron hsp70 genes were analyzed.Under heat shock conditions of 37,39 and 41oC,hsp70-2 mRNA had the highest relative expression level,suggesting it is closely related to heat shock.The basal level of constitutive T.thermophila hsp70-4 gene was high during 20 physiological/developmental stages of growth,starvation and conjugation,and it changed little upon exposure to heat shock：evidence that hsp70-4 is an hsc70 gene.The hsp70-4 cDNA is 2 208 bp long,and contains an open reading frame of 1 959 bp encoding 635 amino acids.Microarray data indicated that T.thermophila hsp70-3 gene probably participated in early starvation（0-12 h） stress and late conjugation（6-10 h） events,such as new macronuclear and micronuclear anlagen formation and old macronuclear elimination.However,hsp70-5 gene possibly participates in late starvation（12-15 h） stress and early conjugation（0-6 h） events such as micronuclear meiosis,micronuclear exchange and pronuclear fusion.Blast2GO indicated that they participated in dissimilar biological processes,suggesting hsp70-3 and hsp70-5 perform different functions.

关 键 词：嗜热四膜虫 HSP70基因 实时荧光定量PCR MICROARRAY RACE 表达分析 

分 类 号：Q78[生物学—分子生物学]