Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park, 2006, South Africa.
Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa.
Sci Rep. 2022 Aug 31;12(1):14810. doi: 10.1038/s41598-022-18407-1.
A longstanding question in evolutionary biology is how natural selection and environmental pressures shape the mitochondrial genomic architectures of organisms. Mitochondria play a pivotal role in cellular respiration and aerobic metabolism, making their genomes functionally highly constrained. Evaluating selective pressures on mitochondrial genes can provide functional and ecological insights into the evolution of organisms. Collembola (springtails) are an ancient hexapod group that includes the oldest terrestrial arthropods in the fossil record, and that are closely associated with soil environments. Of interest is the diversity of habitat stratification preferences (life forms) exhibited by different species within the group. To understand whether signals of positive selection are linked to the evolution of life forms, we analysed 32 published Collembola mitogenomes in a phylomitogenomic framework. We found no evidence that signatures of selection are correlated with the evolution of novel life forms, but rather that mutations have accumulated as a function of time. Our results highlight the importance of nuclear-mitochondrial interactions in the evolution of collembolan life forms and that mitochondrial genomic data should be interpreted with caution, as complex selection signals may complicate evolutionary inferences.
进化生物学中长期存在的一个问题是，自然选择和环境压力如何塑造生物体的线粒体基因组结构。线粒体在细胞呼吸和需氧代谢中起着关键作用，因此其基因组在功能上受到高度限制。评估线粒体基因的选择压力可以为生物体的进化提供功能和生态方面的深入了解。弹尾目（跳虫）是一个古老的六足动物群，包括化石记录中最古老的陆地节肢动物，并且与土壤环境密切相关。有趣的是，该群体内不同物种表现出栖息地分层偏好（生活型）的多样性。为了了解正选择信号是否与生活型的进化有关，我们在系统发生基因组学框架中分析了 32 个已发表的弹尾目线粒体基因组。我们没有发现选择信号与新的生活型进化相关的证据，而是随着时间的推移积累了突变。我们的研究结果强调了核-线粒体相互作用在弹尾目生活型进化中的重要性，并且应该谨慎解释线粒体基因组数据，因为复杂的选择信号可能会使进化推断复杂化。
