Max Planck Institute for Biology of Ageing, Cologne, Germany.
Czech Academy of Sciences, Institute of Vertebrate Biology, Brno, Czech Republic.
Elife. 2020 Sep 1;9:e55794. doi: 10.7554/eLife.55794.
The evolutionary forces shaping life history divergence within species are largely unknown. Turquoise killifish display differences in lifespan among wild populations, representing an ideal natural experiment in evolution and diversification of life history. By combining genome sequencing and population genetics, we investigate the evolutionary forces shaping lifespan among wild turquoise killifish populations. We generate an improved reference genome assembly and identify genes under positive and purifying selection, as well as those evolving neutrally. Short-lived populations from the outer margin of the species range have small population size and accumulate deleterious mutations in genes significantly enriched in the WNT signaling pathway, neurodegeneration, cancer and the mTOR pathway. We propose that limited population size due to habitat fragmentation and repeated population bottlenecks, by increasing the genome-wide mutation load, exacerbates the effects of mutation accumulation and cumulatively contribute to the short adult lifespan.
塑造物种内生活史差异的进化力量在很大程度上是未知的。青绿色的丽鱼在野生种群中表现出寿命的差异，这代表了进化和生活史多样化的理想自然实验。通过结合基因组测序和群体遗传学，我们研究了塑造野生青绿色丽鱼种群寿命的进化力量。我们生成了一个改进的参考基因组组装，并鉴定了正选择和纯化选择下的基因，以及中性进化的基因。来自物种分布范围外部边缘的短寿命种群，其种群规模较小，并在 WNT 信号通路、神经退行性疾病、癌症和 mTOR 通路中显著富集的基因中积累了有害突变。我们提出，由于栖息地破碎化和反复的种群瓶颈导致的有限种群规模，通过增加全基因组突变负荷，加剧了突变积累的影响，并累积导致成年寿命缩短。
