重复元件介导的重组是新嵌合基因形成的一个重要机制

Repetitive Element-Mediated Recombination as a Mechanism for New Gene Origination in Drosophila

先前的研究提示重复元件在产生新的嵌合基因中具有机制性的作用,这与经典的外显子洗牌模型是一致的,它依赖于非同源重组。而近期一些关于染色体异常的研究结果显示,异位的同源重组可能对于产生新基因也非常重要。本项研究通过对8种果蝇的年轻基因进行筛选和分析,从中识别出了17个重复片段,它们是在最近1200万年中通过异位重组形成的。它们中的大多数已具有功能,并进化出多样的表达类型和嵌合结构。这些结果证实,重复元件介导的非等位同源重组在产生新嵌合基因中起到重要作用。

Previous studies of repetitive elements （REs） had implicated a mechanistic role in generating new chimerical genes. sic model Such examples were consistent with the clasfor exon shuffling, which relied on non-homologous recombination. However, recent data for chromosomal aberrations in model organisms suggested that ectopic homology-dependent recombination may also be important. Lack of a dataset comprising experimentally verified young duplicates had hampered an ef- fective examination of these models as well as an investigation of sequence features that mediated the rearrangements. A new research identified 17 new chimerical genes which were generated through ectopic recombination within the last 12 million years by screening eight species within the Drosophila melanogaster subgroup. Analyzing flanking sequence of those young duplicates verified that the repetitive elements （REs） played an important role in the generation of chimerical genes within these species. This research was performed by collaboration between Kunming Institute of Zoology, CAS and Chicago University. The results were published in PLoS Genetics, Jan 2008, 4 （1） ： e3.