Gene duplication events play an important role in the evolution and adaptation of organisms. Duplicated genes can arise through different mechanisms, including whole-genome duplications (WGDs). Recently, WGD was suggested to be an important driver of evolution, also in hexapod animals. Here, we analyzed 20 high-quality hexapod genomes using whole-paranome distributions of estimated synonymous distances (KS), patterns of within-genome co-linearity, and phylogenomic gene tree-species tree reconciliation methods. We observe an abundance of gene duplicates in the majority of these hexapod genomes, yet we find little evidence for WGD. The majority of gene duplicates seem to have originated through small-scale gene duplication processes. We did detect segmental duplications in six genomes, but these lacked the within-genome co-linearity signature typically associated with WGD, and the age of these duplications did not coincide with particular peaks in KS distributions. Furthermore, statistical gene tree-species tree reconciliation failed to support all but one of the previously hypothesized WGDs. Our analyses therefore provide very limited evidence for WGD having played a significant role in the evolution of hexapods and suggest that alternative mechanisms drive gene duplication events in this group of animals. For instance, we propose that, along with small-scale gene duplication events, episodes of increased transposable element activity could have been an important source for gene duplicates in hexapods.

中文翻译：

---

多方面的分析几乎没有提供六足动物进化过程中反复出现的全基因组重复的证据。


基因复制事件在生物体的进化和适应中发挥着重要作用。重复基因可以通过不同的机制产生，包括全基因组重复（WGD）。最近，WGD 被认为是进化的重要驱动力，对于六足动物也是如此。在这里，我们使用估计同义距离（KS）的全副组分布、基因组内共线性模式以及系统发育基因树-物种树协调方法分析了 20 个高质量六足动物基因组。我们在大多数六足动物基因组中观察到大量的基因重复，但我们几乎没有发现 WGD 的证据。大多数基因重复似乎起源于小规模的基因复制过程。我们确实在六个基因组中检测到了片段重复，但这些缺乏通常与 WGD 相关的基因组内共线性特征，并且这些重复的年龄与 KS 分布中的特定峰值不一致。此外，统计基因树-物种树协调未能支持除先前假设的 WGD 之一之外的所有其他结果。因此，我们的分析为 WGD 在六足动物的进化中发挥了重要作用提供了非常有限的证据，并表明替代机制驱动了这组动物的基因复制事件。例如，我们提出，除了小规模的基因复制事件外，转座元件活性增加的事件可能是六足动物基因重复的重要来源。