Rotifer rDNA-specific R9 retrotransposable elements generate an exceptionally long target site duplication upon insertion
Rotifer rDNA-specific R9 retrotransposable elements generate an exceptionally long target site duplication upon insertion
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DOI：
10.1016/j.gene.2009.08.016
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发表时间：
2009-12-15
期刊：
影响因子：
3.5
通讯作者：
Arkhipova, Irina R.
中科院分区：
文献类型：
--
作者：
Gladyshev, Eugene A.;Arkhipova, Irina R.
许多真核生物中的核糖体DNA基因含有属于R2进化枝的非LTR逆转录转座因子的插入。这些元件通过将位点特异性插入多拷贝靶位点而在宿主基因组中持续存在，从而避免单拷贝宿主基因的随机破坏。在这里，我们描述的R9反转录转座子从蛭形轮虫，小型淡水无脊椎动物的28S RNA基因的R2分支，最有名的长期无性繁殖，并为他们的生存能力反复循环的干燥和复水。虽然R9元件的结构组织与R2进化枝的其他成员高度相似，但它们的特征在于两个不同的特征：位点特异性插入到28S基因内先前未报道的靶序列中，以及异常长的126 bp靶位点重复。我们讨论了蛭形基因组组织的背景下，这些研究结果的影响和目标启动逆转录的机制。(c)2009爱思唯尔有限公司版权所有。
Ribosomal DNA genes in many eukaryotes contain insertions of non-LTR retrotransposable elements belonging to the R2 clade. These elements persist in the host genomes by inserting site-specifically into multicopy target sites, thereby avoiding random disruption of single-copy host genes. Here we describe R9 retrotransposons from the R2 clade in the 28S RNA genes of bdelloid rotifers, small freshwater invertebrate animals best known for their long-term asexuality and for their ability to survive repeated cycles of desiccation and rehydration. While the structural organization of R9 elements is highly similar to that of other members of the R2 clade, they are characterized by two distinct features: site-specific insertion into a previously unreported target sequence within the 28S gene, and an unusually long target site duplication of 126 bp. We discuss the implications of these findings in the context of bdelloid genome organization and the mechanisms of target-primed reverse transcription. (c) 2009 Elsevier B.V. All rights reserved.