【作者】 何晓芳； 温硕洋； 庞雄飞；

【Author】 He Xiao fang Wen Shou yang Pang Xinog fei (Lab. of Insect Ecology, South China Agricultural University 510642)

【机构】 华南农业大学昆虫生态研究室；

【摘要】 拟澳洲赤眼蜂是广泛分布世界,用以防治鳞翅目害虫的一种寄生蜂。近年来多以ITS2基因作为标志基因研究其进化与分类特征。ITS2为核糖体DNA上的一段内含子,其具体功能仍未清楚,同时ITS2如何从rRNA前体脱离出来的原理也不清楚。本文对拟澳洲赤眼蜂的五个地理种的ITS2基因序列进行测序并构建种群间的进化关系树。运用热力学原理预测的方法探讨基二级结构物征,并与老鼠和人类的ITS2二级结构进行比较,为研究拟澳洲赤眼蜂在ITS2基因进化、功能打下基础。更多还原

【Abstract】 Mechanisms of ITS2 excision from pre-rRNA remain largely elusive.The major advances on the question have been achieved in yeast.ITS2 gene of five populations of parasitoid wasp, Trchigram confusum Viggiani, were sequenced and used to restructure the evolution tree of these populations. The secondary structures of ITS2 were also predicted. ITS2 can be organized around a preserved central core of secondary structure from which emerge four helices and containing a high level of sequence conservation within the single-stranded segments separating domains. Compared these five populations with rat and human their secondary structures appear preserved in some bases, despite dramatic sequences variations.更多还原