由一个驱动卫星DNA的微型反向重复转座子获得的关于基因组大小进化的见解。

Insights on genome size evolution from a miniature inverted repeat transposon driving a satellite DNA.

作者信息

Scalvenzi Thibault, Pollet Nicolas

机构信息

Institute of Systems and Synthetic Biology, CNRS, Université d'Evry Val d'Essonne, Bâtiment 3, Genopole® campus 3, 1, rue Pierre Fontaine, F-91058 Evry, France.

出版信息

Mol Phylogenet Evol. 2014 Dec;81:1-9. doi: 10.1016/j.ympev.2014.08.014. Epub 2014 Sep 3.

DOI:10.1016/j.ympev.2014.08.014

PMID:25193611

Abstract

The genome size in eukaryotes does not correlate well with the number of genes they contain. We can observe this so-called C-value paradox in amphibian species. By analyzing an amphibian genome we asked how repetitive DNA can impact genome size and architecture. We describe here our discovery of a Tc1/mariner miniature inverted-repeat transposon family present in Xenopus frogs. These transposons named miDNA4 are unique since they contain a satellite DNA motif. We found that miDNA4 measured 331 bp, contained 25 bp long inverted terminal repeat sequences and a sequence motif of 119 bp present as a unique copy or as an array of 2-47 copies. We characterized the structure, dynamics, impact and evolution of the miDNA4 family and its satellite DNA in Xenopus frog genomes. This led us to propose a model for the evolution of these two repeated sequences and how they can synergize to increase genome size.

摘要

真核生物的基因组大小与其所含基因数量并无很好的相关性。我们可以在两栖类物种中观察到这种所谓的C值悖论。通过分析一个两栖类基因组，我们探究了重复DNA如何影响基因组大小和结构。我们在此描述了我们在非洲爪蟾中发现的一个Tc1/水手型微型反向重复转座子家族。这些名为miDNA4的转座子很独特，因为它们包含一个卫星DNA基序。我们发现miDNA4长度为331 bp，含有25 bp长的反向末端重复序列以及一个119 bp的序列基序，该基序以单拷贝形式存在或呈2 - 47个拷贝的阵列形式存在。我们对非洲爪蟾基因组中miDNA4家族及其卫星DNA的结构、动态变化、影响和进化进行了表征。这使我们提出了一个关于这两个重复序列进化以及它们如何协同作用以增加基因组大小的模型。