Bitter M C, Greenblum S, Rajpurohit S, Bergland A O, Hemker J A, Betancourt N J, Tilk S, Berardi S, Oken H, Schmidt P, Petrov D A
Department of Biology, Stanford University, Stanford, CA, USA.
DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
bioRxiv. 2024 Oct 29:2024.10.28.620721. doi: 10.1101/2024.10.28.620721.
Life-history trade-offs are an inherent feature of organismal biology that evolutionary theory posits play a key role in patterns of divergence within and between species. Efforts to quantify trade-offs are largely confined to phenotypic measurements and the identification of negative genetic-correlations among fitness-relevant traits. Here, we use time-series genomic data collected during experimental evolution in large, genetically diverse populations of to directly measure the manifestation of trade-offs in response to temporally fluctuating selection pressures on ecological timescales. Specifically, we quantify the genome-wide signal of antagonistic pleiotropy suggestive of trade-offs between reproduction and stress tolerance. We further identify a putative role of two cosmopolitan inversions in these trade-offs, and show that loci responding to selection during lab-based, reproduction selection exhibit signals of fluctuating selection in an outdoor mesocosm exposed to natural environmental conditions. Our results demonstrate the utility of time-series genomic data in revealing the presence and genomic architecture underlying fitness trade-offs, and add credence to models positing a role of generic life history trade-offs in the maintenance of variation in natural populations.
生活史权衡是生物生物学的一个固有特征，进化理论认为其在物种内部和物种之间的分化模式中起着关键作用。量化权衡的努力主要局限于表型测量以及确定与适应性相关性状之间的负遗传相关性。在这里，我们使用在大型、基因多样化的种群的实验进化过程中收集的时间序列基因组数据，以直接测量在生态时间尺度上对随时间波动的选择压力作出反应时权衡的表现。具体而言，我们量化了拮抗多效性的全基因组信号，这表明在繁殖和应激耐受性之间存在权衡。我们进一步确定了两个常见倒位在这些权衡中的假定作用，并表明在基于实验室的繁殖选择过程中对选择作出反应的基因座，在暴露于自然环境条件的室外中型生态系统中表现出波动选择的信号。我们的结果证明了时间序列基因组数据在揭示适应性权衡的存在及其基因组结构方面的效用，并为认为一般生活史权衡在维持自然种群变异中起作用的模型提供了支持。
