果蝇限制端粒转座子的分子机制  

The molecular mechanism of Drosophila restricting telomeric transposons

作　　者：王承贤 容益康 崔敏 Chengxian Wang;Yikang S.Rong;Min Cui(Hengyang Medical College,University of South China,Hengyang 421200,China)

机构地区：[1]南华大学衡阳医学院,衡阳421200

出　　处：《遗传》2023年第3期221-228,共8页Hereditas（Beijing)

基　　金：南华大学人才经费项目(编号:191RGC001)资助。

摘　　要：端粒是保护线性染色体末端的核酸-蛋白复合物。与常见的真核生物短重复序列组成的端粒不同,黑腹果蝇(Drosophila melanogaster)端粒DNA由反转座子组成,其转座行为被果蝇宿主严格限制在端粒,既实现延长端粒的功能,也减少转座子跳跃对基因组的损伤。但果蝇宿主是如何完成如此精确调控的机制尚不明确。目前已知的全基因组范围抑制转座子表达包括H3K9me3参与的异染色质形成途径和piRNA路径,而近期研究发现果蝇端粒保护蛋白参与端粒反转座子的特异调控。本文主要综述了端粒保护蛋白在调控端粒转座子中的具体功能。对果蝇端粒转座子调控的研究有利于更好地理解宿主与转座子协同进化的分子机制。Linear chromosomes of eukaryotes are protected by a DNA-protein-RNA structure called telomere.Remarkably and unlike those of most organisms studied,Drosophila telomeric DNA is not composed of a group of short repeats,but three classes of retrotransposons at the chromosome ends.Telomeric transposons in Drosophila on the other hand serves the function of elongating the host chromosomes yet prevent little harm to the host genome as their insertion sites are strictly limited to the telomere.How the Drosophila host achieves such precise regulation is still unclear.The currently known genome-wide repression of transposon expression includes piRNA pathway and the heterochromatin pathway involving H3K9me3.Recent studies have found that Drosophila telomere capping proteins are involved in the specific regulation of telomeric retrotransposons.In this review,we discuss the specific functions of telomere capping proteins in regulating telomeric transposons.By studying how the Drosophila host interacts and regulates telomeric transposons,we hope to shed lights on universal principles in guiding their co-evolution.

关 键 词：端粒保护蛋白 反转座子 转座子转录调控 PIRNA 端粒酶 

分 类 号：Q343.2[生物学—遗传学]