Sauria SINEs: Novel short interspersed retroposable elements that are widespread in reptile genomes
Sauria SINEs: Novel short interspersed retroposable elements that are widespread in reptile genomes
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DOI：
10.1007/s00239-005-0201-5
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发表时间：
2006-05-01
影响因子：
3.9
通讯作者：
Okada, Norihiro
中科院分区：
文献类型：
--
作者：
Piskurek, Oliver;Austin, Christopher C.;Okada, Norihiro
西内斯是短的散布的反转录转座因子，侵入新的基因组位点。它们的逆转录转座依赖于由伴侣LINE（长散布元件）编码的逆转录酶和核酸内切酶活性。最近的基因组研究表明，逆转录酶至少占人类基因组的40%。迄今为止，哺乳动物基因组中已经发现了30多个西内斯家族，约有4600个现存物种;然而，西内斯在爬行动物基因组中的分布和程度却鲜有报道。有超过7400种蜥蜴和蛇，有鳞目构成了最大和最多样化的爬行动物群体。我们发现并鉴定了一个新的SINE家族，Sauria西内斯，其成员广泛分布于蜥蜴，蛇和蜥蜴的基因组中。蜥类西内斯包含源自LINE的5'tRNA相关区、tRNA不相关区和3'尾区（含有短串联重复序列）。我们区分了四个主要的有鳞动物谱系的基因组中的八个SINE蜥亚科，并研究了它们的进化关系。我们的数据说明了整体疗效的蜥脚类西内斯作为新的逆转录转座标记阐明鳞片的进化历史。我们表明，所有Sauria西内斯与Bov-B LINES共享相同的3'序列，并提出它们利用Bov-B LINES的酶机制进行自身的反转录转座。这一发现，沿着Bov-B LINE先前在有鳞动物基因组中的普遍存在，表明这些LINE自2亿多年前SINE家族产生以来一直是Sauria西内斯的活跃伴侣。
SINEs are short interspersed retrotransposable elements that invade new genomic sites. Their retrotransposition depends on reverse transcriptase and endonuclease activities encoded by partner LINEs (long interspersed elements). Recent genomic research has demonstrated that retroposons account for at least 40% of the human genome. Hitherto, more than 30 families of SINEs have been characterized in mammalian genomes, comprising similar to 4600 extant species; the distribution and extent of SINEs in reptilian genomes, however, are poorly documented. With more than 7400 species of lizards and snakes, Squamata constitutes the largest and most diverse group of living reptiles. We have discovered and characterized a novel SINE family, Sauria SINEs, whose members are widely distributed among genomes of lizards, snakes, and tuataras. Sauria SINEs comprise a 5' tRNA-related region, a tRNA-unrelated region, and a 3' tail region (containing short tandem repeats) derived from LINEs. We distinguished eight Sauria SINE subfamilies in genomes of four major squamate lineages and investigated their evolutionary relationships. Our data illustrate the overall efficacy of Sauria SINEs as novel retrotransposable markers for elucidation of squamate evolutionary history. We show that all Sauria SINEs share an identical 3' sequence with Bov-B LINEs and propose that they utilize the enzymatic machinery of Bov-B LINEs for their own retrotransposition. This finding, along with the ubiquity of Bov-B LINEs previously demonstrated in squamate genomes, suggests that these LINEs have been an active partner of Sauria SINEs since this SINE family was generated more than 200 million years ago.