近縁種で独立に生じた全ゲノム重複が解明する全ゲノム重複のメカニズムとインパクト

在这个项目中，我们的目标是了解新功能化和亚功能化是如何发生的，以及它们是由特定的遗传元件驱动的还是由基因组多倍体化后附近基因的功能驱动的。在新测序的真菌基因组中鉴定和鉴定基因组多倍体化后，我们研究了直系同源和类似性的进化速率，新形成的邻近基因的转录取向，以及蛋白质复合物和生物途径组分的化学计量学保守性。在这一年里，我们报道了在真菌属Trichosporon的一个分支中最近发现的两个独立的基因组杂交。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。

In this project, we aim to understand how neofunctionalization and subfunctionalization occur and whether they are driven by particular genetic elements or functions of nearby genes after genome polyploidization. Following the identification and characterization of genome polyploidization in newly sequenced fungal genomes, we investigated evolution rates among orthologs and paralogs, transcriptional orientation of newly formed adjacent genes, and conservations of stoichiometry for protein complexes and biological pathway components. In this year, we reported 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.