Global deceleration of gene evolution following recent genome hybridizations in fungi.
Global deceleration of gene evolution following recent genome hybridizations in fungi.
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DOI：
10.1101/gr.205948.116
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发表时间：
2016-08
期刊：
影响因子：
7
通讯作者：
Iwasaki W
中科院分区：
文献类型：
--
作者：
Sriswasdi S;Takashima M;Manabe R;Ohkuma M;Sugita T;Iwasaki W
多倍体化事件，如全基因组复制和种间杂交是形成基因组的主要进化力量。虽然多倍体化的长期影响已经被很好地描述，但多倍体化的早期分子进化后果在很大程度上仍未被探索。在这里，我们报告了在真菌属Trichosporon的一个分支中发现的两个最近独立的基因组杂交。比较基因组分析显示，冗余基因正在经历进化速度的减速，而不是加速。我们发现了基因转换与进化减速之间的关系，这表明基因转换可能通过限制基因功能分歧来提高年轻杂交种的基因组稳定性。此外，我们从转录和翻译机制中检测到大规模的基因损失，这表明针对基因剂量增加的全球补偿机制。总的来说，我们的研究结果说明了后基因组杂交早期阶段的抵消机制，填补了现有基因组进化理论的关键空白。
Polyploidization events such as whole-genome duplication and inter-species hybridization are major evolutionary forces that shape genomes. Although long-term effects of polyploidization have been well-characterized, early molecular evolutionary consequences of polyploidization remain largely unexplored. Here, we report the discovery of two recent and independent genome hybridizations within a single clade of a fungal genus, Trichosporon. Comparative genomic analyses revealed that redundant genes are experiencing decelerations, not accelerations, of evolutionary rates. We identified a relationship between gene conversion and decelerated evolution suggesting that gene conversion may improve the genome stability of young hybrids by restricting gene functional divergences. Furthermore, we detected large-scale gene losses from transcriptional and translational machineries that indicate a global compensatory mechanism against increased gene dosages. Overall, our findings illustrate counteracting mechanisms during an early phase of post-genome hybridization and fill a critical gap in existing theories on genome evolution.