瑞典古遗传学中心Love Dalén和Marianne Dehasque共同合作，近期取得重要工作进展。他们研究提出了长毛象灭绝前基因组侵蚀的时间动力学。相关研究成果2024年6月27日在线发表于《细胞》杂志上。
据介绍，许多物种最近从濒临灭绝的状态中恢复过来。尽管这些物种避免了直接的灭绝威胁，但由于种群减少的潜在遗传后果，它们的长期生存能力仍然不稳定，而在几代人之后的时间尺度上，人们对其了解甚少。长毛象大约1万年前在弗兰格尔岛上被隔离，并持续了200多代，大约4000年前灭绝。
为了研究导致长毛象灭绝的演化过程，研究人员分析了21只西伯利亚长毛象的基因组。研究结果表明，长毛象的种群从严重的瓶颈中迅速恢复，并在随后的6000年中保持稳定。研究人员发现，轻度有害的突变逐渐积累，而高度有害的突变被清除，这表明持续了数百代的近亲繁殖抑制。种群数量统计和基因恢复之间的时间滞后对最近陷入瓶颈的种群的保护管理有着广泛的影响。
附：英文原文
Title: Temporal dynamics of woolly mammoth genome erosion prior to extinction
Author: Marianne Dehasque, Hernán E. Morales, David Díez-del-Molino, Patrícia Penerová, J. Camilo Chacón-Duque, Foteini Kanellidou, Hélose Muller, Valerii Plotnikov, Albert Protopopov, Alexei Tikhonov, Pavel Nikolskiy, Gleb K. Danilov, Maddalena Giannì, Laura van der Sluis, Tom Higham, Peter D. Heintzman, Nikolay Oskolkov, M. Thomas P. Gilbert, Anders Gtherstrm, Tom van der Valk, Sergey Vartanyan, Love Dalén
Issue&Volume: 2024-06-27
Abstract: A number of species have recently recovered from near-extinction. Although these species have avoided the immediate extinction threat, their long-term viability remains precarious due to the potential genetic consequences of population declines, which are poorly understood on a timescale beyond a few generations. Woolly mammoths (Mammuthus primigenius) became isolated on Wrangel Island around 10,000 years ago and persisted for over 200 generations before becoming extinct around 4,000 years ago. To study the evolutionary processes leading up to the mammoths’ extinction, we analyzed 21 Siberian woolly mammoth genomes. Our results show that the population recovered quickly from a severe bottleneck and remained demographically stable during the ensuing six millennia. We find that mildly deleterious mutations gradually accumulated, whereas highly deleterious mutations were purged, suggesting ongoing inbreeding depression that lasted for hundreds of generations. The time-lag between demographic and genetic recovery has wide-ranging implications for conservation management of recently bottlenecked populations.
DOI: 10.1016/j.cell.2024.05.033
Source: https://www.cell.com/cell/fulltext/S0092-8674(24)00577-4