本地适应岛屿果蝇中的染色体重排与转座元件
Chromosomal rearrangements and transposable elements in locally adapted island Drosophila
AI总结：
本文以圣多美岛两种本地适应果蝇为研究对象，分析染色体重排的进化作用，发现其与转座元件显著关联，鉴定出大量适应性重排，揭示其通过改变基因表达推动本地适应，为进化研究提供新视角。
摘要：
染色体重排（尤其是转座元件（TEs）介导的染色体重排）可通过产生嵌合基因、诱导从头基因形成或改变基因表达来推动适应性进化。本文研究了两个本地适应种群——分别在圣多美岛栖息50万年和1万年的圣多美果蝇（Drosophila santomea）与雅库巴果蝇（Drosophila yakuba）——在栖息地转变过程中染色体重排的进化作用。利用雅库巴果蝇-圣多美果蝇物种复合体，我们在两个岛屿种群及雅库巴果蝇的非洲大陆祖先种群中鉴定出16480个染色体重排。研究发现染色体重排与TEs存在显著关联，83.5%的重排与TE插入或TE介导的异位重组相关。基于中性期望的显著性阈值，我们鉴定出岛屿雅库巴果蝇和圣多美果蝇中分别有383个和468个与大陆种群相比显著分化的重排。其中99个和145个重排还表现出显著的差异基因表达，突显了重排与TEs产生适应性解决方案的潜力。在岛屿种群内部及之间，我们发现源自新突变与遗传变异的重排比例因TE关联而显著不同，这可能表明适应性遗传机制因栖息地转变时间而异。对最可能推动本地适应的重排进行功能分析后发现，高海拔圣多美果蝇中应激反应通路（包括紫外线耐受性和DNA修复）显著富集。这些发现表明染色体重排可能是遗传创新的来源，并为单核苷酸多态性（SNP）分析可能忽略的进化过程提供了见解。
英文摘要：
Chromosomal rearrangements, particularly those mediated by transposable elements (TEs), can drive adaptive evolution by creating chimeric genes, inducing de novo gene formation, or altering gene expression. Here, we investigate rearrangements evolutionary role during habitat shifts in two locally adapted populations, Drosphila santomea and Drosphila yakuba, who have inhabited the island São Tomé for 500,000 and 10,000 years respectively. Using the D. yakuba- D. santomea species complex, we identified 16,480 rearrangements in the two island populations and the ancestral mainland African population of D. yakuba. We find a disproportionate association with TEs, with 83.5% of rearrangements linked to TE insertions or TE-facilitated ectopic recombination. Using significance thresholds based on neutral expectations, we identify 383 and 468 significantly differentiated rearrangements in island D. yakuba and D. santomea, respectively, relative to the mainland population. Of these, 99 and 145 rearrangements also showed significant differential gene expression, highlighting the potential for adaptive solutions from rearrangements and TEs. Within and between island populations, we find significantly different proportions of rearrangements originating from new mutations versus standing variation depending on TE association, potentially suggesting adaptive genetic mechanisms differ based on the timing of habitat shifts. Functional analyses of rearrangements most likely driving local adaptation revealed enrichment for stress response pathways, including UV tolerance and DNA repair, in high-altitude D. santomea. These findings suggest that chromosomal rearrangements may act as a source of genetic innovation, and provides insight into evolutionary processes that SNP-based analyses might overlook.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
