The Impact of Whole Genome Duplication on the Evolution of the Arachnids
The Impact of Whole Genome Duplication on the Evolution of the Arachnids
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DOI：
10.1093/icb/icad050
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发表时间：
2023-06-01
影响因子：
2.6
通讯作者：
Sharma，Prashant P.
中科院分区：
文献类型：
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作者：
Sharma，Prashant P.
过去十年中螯肢动物基因组资源的激增表明，螯肢动物基因组的进化比之前想象的更加动态，古代全基因组复制的多次浪潮影响着不同的谱系。从进化史的角度来看，这种复制事件是令人着迷的，因为与基因组复制相关的新基因拷贝的爆发促进了新基因功能（新功能化）的获得，这反过来可能导致形态上的新颖性并刺激网络多样化。虽然新功能化已在蜘蛛的成功和多样性方面被引用，但全基因组复制对螯类进化和发育的总体影响仍不完全清楚。本综述的目的是批判性地研究全基因组复制对现存蜘蛛目多样化的作用，并评估功能数据集以获取螯类亚功能化或新功能化的证据。这项检查的重点是来自两个焦点模型类群的功能数据：蜘蛛Parasteatoda tepidariorum，它展示了古代重复的证据，以及收获者Phalangium opilio，它展示了未重复的基因组。我表明没有证据表明具有基因组重复的类群比具有不重复基因组的类群更成功。我认为，尽管这一假设对于解释像蜘蛛这样的群体的成功很有吸引力，但目前蜘蛛中重复发育模式基因的亚功能化或新功能化的证据是间接的或零碎的。现有的表达数据表明，Hox 模块重复的情况可能在促进某些目（例如蜘蛛和蝎子）后标签的身体计划差异方面发挥了作用，但证实这一假设的功能数据严重缺失。蜘蛛中重复转录因子的时空动态可能代表发育系统漂移的情况，而不是新功能化的情况。发育系统漂移可能代表了螯虫发育生物学中旁系同源物研究的一个重要但被忽视的零假设。为了区分亚功能化、新功能化和发育系统漂移，迫切需要同时从表现出基因组重复的类群以及缺乏同源性的类群中建立比较功能数据集。
The proliferation of genomic resources for Chelicerata in the past 10 years has revealed that the evolution of chelicerate genomes is more dynamic than previously thought, with multiple waves of ancient whole genome duplications affecting separate lineages. Such duplication events are fascinating from the perspective of evolutionary history because the burst of new gene copies associated with genome duplications facilitates the acquisition of new gene functions (neofunctionalization), which may in turn lead to morphological novelties and spur net diversification. While neofunctionalization has been invoked in several contexts with respect to the success and diversity of spiders, the overall impact of whole genome duplications on chelicerate evolution and development remains imperfectly understood. The purpose of this review is to examine critically the role of whole genome duplication on the diversification of the extant arachnid orders, as well as assess functional datasets for evidence of subfunctionalization or neofunctionalization in chelicerates. This examination focuses on functional data from two focal model taxa: the spiderParasteatoda tepidariorum, which exhibits evidence for an ancient duplication, and the harvestmanPhalangium opilio, which exhibits an unduplicated genome. I show that there is no evidence that taxa with genome duplications are more successful than taxa with unduplicated genomes. I contend that evidence for sub- or neofunctionalization of duplicated developmental patterning genes in spiders is indirect or fragmentary at present, despite the appeal of this postulate for explaining the success of groups like spiders. Available expression data suggest that the condition of duplicated Hox modules may have played a role in promoting body plan disparity in the posterior tagma of some orders, such as spiders and scorpions, but functional data substantiating this postulate are critically missing. Spatiotemporal dynamics of duplicated transcription factors in spiders may represent cases of developmental system drift, rather than neofunctionalization. Developmental system drift may represent an important, but overlooked, null hypothesis for studies of paralogs in chelicerate developmental biology. To distinguish between subfunctionalization, neofunctionalization, and developmental system drift, concomitant establishment of comparative functional datasets from taxa exhibiting the genome duplication, as well as those that lack the paralogy, is sorely needed.