Flegontov Pavel N, Guo Qiang, Ren Lina, Strelkova Margarita V, Kolesnikov Alexander A
Department of Molecular Biology, Lomonosov Moscow State University, Vorobjevy Gory 1, build. 12, 119992, Moscow, Russia.
Mol Genet Genomics. 2006 Oct;276(4):322-33. doi: 10.1007/s00438-006-0145-5. Epub 2006 Aug 15.
The maxicircle control region [also termed divergent region (DR)] composed of various repeat elements remains the most poorly studied part of the kinetoplast genome. Only three extensive DR sequences demonstrating no significant similarity were available for trypanosomatids (Leishmania tarentolae, Crithidia oncopelti, Trypanosoma brucei). Recently, extensive DR sequences have been obtained for Leishmania major and Trypanosoma cruzi. In this work we have sequenced DR fragments of Leishmania turanica, Leishmania mexicana, Leishmania chagasi and two monogenetic trypanosomatids Leptomonas seymouri and Leptomonas collosoma. With the emergence of the additional extensive sequences some conserved features of DR structure become evident. A conserved palindromic sequence has been revealed in the DRs of the studied Leishmania species, L. seymouri, and T. cruzi. The overall DR structure appears to be similar in all the Leishmania species, their relative L. seymouri, and T. brucei: long relatively GC-rich repeats are interspersed with clusters of short AT-rich repeats. C. oncopelti, L. collosoma, and T. cruzi have a completely different DR structure. Identification of conserved sequences and invariable structural features of the DR may further our understanding of the functioning of this important genome fragment.
由各种重复元件组成的大环控制区[也称为发散区（DR）]仍然是动质体基因组中研究最少的部分。对于锥虫（细滴虫、克氏锥虫、布氏锥虫），仅有三个无显著相似性的长发散区序列。最近，已获得了硕大利什曼原虫和克氏锥虫的长发散区序列。在这项研究中，我们对图兰利什曼原虫、墨西哥利什曼原虫、恰加斯利什曼原虫以及两种单殖性锥虫西氏细滴虫和粗线细滴虫的发散区片段进行了测序。随着更多长序列的出现，发散区结构的一些保守特征变得明显。在所研究的利什曼原虫物种、西氏细滴虫和克氏锥虫的发散区中发现了一个保守的回文序列。所有利什曼原虫物种、它们相对的西氏细滴虫以及布氏锥虫的发散区总体结构似乎相似：相对富含GC的长重复序列与富含AT的短重复序列簇相间排列。克氏锥虫、粗线细滴虫和克氏锥虫具有完全不同的发散区结构。鉴定发散区的保守序列和不变的结构特征可能会增进我们对这个重要基因组片段功能的理解。
