Low persistence of genetic rescue across generations in the Arctic fox (Vulpes lagopus)

Genetic rescue can facilitate the recovery of small and isolated populations suffering from inbreeding depression. Long-term effects are however complex and examples spanning over multiple generations under natural conditions are scarce. The aim of this study was to test for long-term effects of natural genetic rescue in a small population of Scandinavian Arctic foxes (Vulpes lagopus). By combining a genetically verified pedigree covering almost 20 years with a long-term dataset on individual fitness (n=837 individuals), we found no evidence for elevated fitness in immigrant F2 and F3 compared to native inbred foxes. Population inbreeding levels showed a fluctuating increasing trend and emergence of inbreeding within immigrant lineages shortly after immigration. Between 0-5 and 6-9 years post immigration, the average population size decreased by almost 22 % and the average proportion of immigrant ancestry rose from 14 % to 27 %. Y chromosome analysis revealed that two out of three nativ...遗传拯救（genetic rescue）可促进受近交衰退（inbreeding depression）困扰的小型孤立种群的恢复。然而其长期效应较为复杂，且自然环境下跨多世代的相关研究案例较为稀缺。本研究以斯堪的纳维亚北极狐（Vulpes lagopus）的一个小型种群为研究对象，旨在检验自然遗传拯救的长期效应。本研究结合了覆盖近20年的经遗传学验证的家系谱系，与包含837个个体的长期个体适合度数据集，结果显示，与本土近交北极狐相比，外来二代（F2）与三代（F3）个体的适合度并未出现显著提升。种群近交水平呈现波动上升趋势，且在移民个体迁入后不久，外来世系内部便出现了近交现象。在移民迁入后的0-5年与6-9年两个时段内，种群平均规模下降近22%，而外来祖先占种群遗传背景的比例则从14%升至27%。Y染色体分析显示，三只本土个体中的两只……