Out of the testis, into the ovary: biased outcomes of gene duplication and deletion in Drosophila
Out of the testis, into the ovary: biased outcomes of gene duplication and deletion in Drosophila
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DOI：
10.1111/evo.13820
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发表时间：
2019-09-01
期刊：
影响因子：
3.3
通讯作者：
Assis, Raquel
中科院分区：
文献类型：
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作者：
Assis, Raquel
基因更新是适应性变异的一个重要来源。然而，大多数进化研究都集中在基因复制上，而忽视了基因删除作为一种简单的消除冗余的机制。在这里，我使用基因组规模的序列和多组织表达数据从果蝇和果蝇pseudobscura同时评估果蝇基因重复和缺失的进化结果。我发现在这两个物种中，基因重复比基因缺失更频繁，这表明它可能在果蝇进化中起着更重要的作用。然而，几个基因特性的检查显示，基因可能具有不同的功能，复制后，删除前进一步分歧，这表明冗余的损失不能解释大多数果蝇基因缺失事件。此外，除了提供支持的公知的“出睾丸”的年轻的重复基因的起源，基因表达谱的分析揭示了对旧的卵巢表达的基因的删除的偏好偏差。因此，我提出了一个新的“进入卵巢”的假设，在果蝇基因缺失，基因缺失可能会促进适应打捞基因，有助于女性生殖表型的进化。在这种结合的“出睾丸，进卵巢”的进化模式下，基因复制和缺失协同工作，以产生和维持一个平衡的基因库，促进果蝇的性别特异性适应。
Gene turnover is a key source of adaptive variation. Yet most evolutionary studies have focused on gene duplication, dismissing gene deletion as a mechanism that simply eradicates redundancy. Here, I use genome-scale sequence and multi-tissue expression data from Drosophila melanogaster and Drosophila pseudoobscura to simultaneously assess the evolutionary outcomes of gene duplication and deletion in Drosophila. I find that gene duplication is more frequent than gene deletion in both species, indicating that it may play a more important role in Drosophila evolution. However, examination of several genic properties reveals that genes likely possess distinct functions after duplication that diverge further before deletion, suggesting that loss of redundancy cannot explain a majority of gene deletion events in Drosophila. Moreover, in addition to providing support for the well-known "out of the testis" origin of young duplicate genes, analyses of gene expression profiles uncover a preferential bias against deletion of old ovary-expressed genes. Therefore, I propose a novel "into the ovary" hypothesis for gene deletion in Drosophila, in which gene deletion may promote adaptation by salvaging genes that contribute to the evolution of female reproductive phenotypes. Under this combined "out of the testis, into the ovary" evolutionary model, gene duplication and deletion work in concert to generate and maintain a balanced repertoire of genes that promote sex-specific adaptation in Drosophila.