甜菜夜蛾生物钟基因Per和Tim的分子克隆及昼夜表达动态

针对重要农业害虫甜菜夜蛾,通过序列相似性分析从转录组数据获得2个生物钟基因片段,利用RACE技术进一步克隆了cDNA全序列,分别命名为SexiPer和SexiTim。2个基因编码的氨基酸序列和已报道的昆虫同源序列具有较高的相似性,其中SexiPer和海灰翅夜蛾、甘蓝夜蛾的相似性最高,分别为71%和52%;SexiTim和家蚕、柞蚕的相似性最高,分别为65%和52%。进化分析表明,Per基因的氨基酸序列相似性与昆虫间的亲缘关系非常一致,但Tim基因不太一致。进一步利用qRT-PCR技术,对雄蛾触角中2个基因的昼夜表达动态进行了测定,发现2个基因表达量的变化同步,均在光期前期较低,光期后期开始升高,至光期末期达到最高,并在整个暗期保持较高水平。研究认为,甜菜夜蛾触角中可能存在着生物钟,用于调控性信息素通讯的昼夜节律。

Molecular identification and diurnal expression of clock gene Per and Tim in the common cutworm,Spodoptera exigua(Hübner)

Two full-length cDNAs of clock genes were cloned from Spodoptera exigua(Hübner) by combination use of informatics and RACE stretegy.The genes were named as SexiPer and SexiTim,with GenBank accession numbers of HQ731034 and HQ731035,respectively.The two genes were highly identical in amino acid sequnces to the orthologues of other insects,with identities of 71% and 52% for SexiPer to those in S.littoralis and Mamestra brassicae,and 65% and 52% for SexiTim to those in Bombyx mori and Antheraea pernyi.Phylogenetic trees showed that the grouping of Per genes from different insects well agreed with phylogenetic relations among these insects,but Tim genes displayed some discrepancy.Finally,the diurnal expression patterns of the two clock genes were determined by quantative real time PCR(qRT-PCR).The two genes showed similar diurnal variations,with low expression in early scotophase,rapid increasing to a peak in late scotophase,and keeping higher level in photophase.We concluded that the circadian clock genes may be involved in controling the diurnal rythem of sex commnication in S.exigua.