Howard Hughes Medical Institute and Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Proc Natl Acad Sci U S A. 2013 Jan 2;110(1):234-9. doi: 10.1073/pnas.1217548110. Epub 2012 Dec 17.
A revelation of the genomic age has been the contributions of the mobile DNA segments called transposable elements to chromosome structure, function, and evolution in virtually all organisms. Substantial fractions of vertebrate genomes derive from transposable elements, being dominated by retroelements that move via RNA intermediates. Although many of these elements have been inactivated by mutation, several active retroelements remain. Vertebrate genomes also contain substantial quantities and a high diversity of cut-and-paste DNA transposons, but no active representative of this class has been identified in mammals. Here we show that a cut-and-paste element called piggyBat, which has recently invaded the genome of the little brown bat (Myotis lucifugus) and is a member of the piggyBac superfamily, is active in its native form in transposition assays in bat and human cultured cells, as well as in the yeast Saccharomyces cerevisiae. Our study suggests that some DNA transposons are still actively shaping some mammalian genomes and reveals an unprecedented opportunity to study the mechanism, regulation, and genomic impact of cut-and-paste transposition in a natural mammalian host.
基因组时代的一个发现是，可移动的 DNA 片段，即转座元件，对几乎所有生物的染色体结构、功能和进化都有贡献。脊椎动物基因组的很大一部分来自转座元件，主要是通过 RNA 中间体移动的反转录转座子。尽管这些元件中的许多已经通过突变失活，但仍有几个活跃的反转录转座子存在。脊椎动物基因组还包含大量的、高度多样化的“剪切-粘贴”DNA 转座子，但在哺乳动物中尚未发现这种类型的活跃代表。在这里，我们展示了一个名为“piggyBat”的“剪切-粘贴”元件，它最近入侵了小棕蝠（Myotis lucifugus）的基因组，是 piggyBac 超家族的成员，在蝙蝠和人类培养细胞以及酵母酿酒酵母中的转座测定中以其天然形式活跃。我们的研究表明，一些 DNA 转座子仍在积极塑造一些哺乳动物基因组，并揭示了一个前所未有的机会，可以在天然哺乳动物宿主中研究“剪切-粘贴”转座的机制、调节和基因组影响。
