Identification of non-autonomous non-LTR retrotransposons in the genome of Trypanosoma cruzi
Identification of non-autonomous non-LTR retrotransposons in the genome of Trypanosoma cruzi
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DOI：
10.1016/s0166-6851(02)00167-6
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发表时间：
2002-09-01
影响因子：
1.5
通讯作者：
Lopez, MC
中科院分区：
文献类型：
--
作者：
Bringaud, F;García-Pérez, JL;Lopez, MC
正如对大多数真核细胞所观察到的，锥虫含有随机插入核基因组中的非LTR反转录转座子。自主的逆转录因子，编码自己的转座，已在布氏锥虫（ingi）和克氏锥虫（L1Tc）的特点，而非自主的逆转录因子的特点，只有在布氏锥虫（RIME）。在这里，我们已经在克氏锥虫的基因组中表征了四个完整的非自主非LTR反转录转座子拷贝，称为NARTc。该0.26 kb NARTc元件具有非LTR反转录转座子的特征：存在多聚（dA）尾和短侧翼重复基序。基因组调查序列数据库的分析表明，克氏锥虫单倍体基因组含有约140个NARTc拷贝和约两倍多的L1Tc拷贝。有趣的是，NARTc和L1Tc逆转录元件与布氏锥虫和RIME逆转录转座子共享一个共同的序列（前45 bp具有91%的同一性），而其余序列非常不同。这表明这四个锥虫非LTR反转录转座子来源于相同的共同祖先，并且它们的5 '端序列可能具有功能作用。此外，硕大利什曼原虫的基因组含有与锥虫逆转录因子相同的保守基序，而迄今为止在利什曼原虫中未检测到转座因子。（C）2002 Elsevier Science B.V.版权所有。
As observed for most eukaryotic cells, trypanosomatids contains non-LTR retrotransposons randomly inserted in the nuclear genome. Autonomous retroelements which, code for their own transposition, have been characterized in Trypanosoma brucei (ingi) and Trypanosoma cruzi (L1Tc), whereas non-autonomous retroelements have only been characterized in T brucei (RIME). Here, we have characterized in the genome of Trypanosoma cruzi four complete copies of a non-autonomous non-LTR retrotransposon, called NARTc. This 0.26 kb NARTc element has the characteristics of non-LTR retrotransposons: the presence a poly(dA) tail and of a short flanking duplicated motif. Analysis of the Genome Survey Sequence databases indicated that the Trypanosoma cruzi haploid genome contains about 140 NARTc copies and about twice as many L1Tc copies. Interestingly, the NARTc and L1Tc retroelements share, with the Trypanosoma brucei ingi and RIME retrotransposons, a common sequence (the first 45 bp with 91% identity), whereas the remaining sequences are very divergent. This suggests that these four trypanosome non-LTR retrotransposons were derived from the same common ancester and the sequence of their 5'-extremity may have a functional role. In addition, the genome of Leishmania major contains the same conserved motif present in the trypanosome retroelements, whicle no transposable elements have been detected so far in Leishmania sp. (C) 2002 Elsevier Science B.V. All rights reserved.