Department of Zoology, Stockholm University, Stockholm, Sweden.
Centre for Palaeogenetics, Svante Arrhenius väg 20C, Stockholm, Sweden.
Nat Commun. 2024 Sep 27;15(1):8378. doi: 10.1038/s41467-024-52741-4.
Inbreeding depression has been documented in various fitness traits in a wide range of species and taxa, however, the mutational basis is not yet well understood. We investigate how putatively deleterious variation influences fitness and is shaped by individual ancestry by re-sequencing complete genomes of 37 individuals in a natural arctic fox (Vulpes lagopus) population subjected to both inbreeding depression and genetic rescue. We find that individuals with high proportion of homozygous loss of function genotypes (LoFs), which are predicted to exert a strong effect on fitness, generally have lower lifetime reproductive success and live shorter lives compared with individuals with lower proportion of LoFs. We also find that juvenile survival is negatively associated with the proportion of homozygous missense genotypes and positively associated with genome wide heterozygosity. Our results demonstrate that homozygosity of strongly and moderately deleterious mutations can be an important cause of trait specific inbreeding depression in wild populations, and mark an important step towards making more informed decisions using applied conservation genetics.
近亲繁殖衰退已在广泛的物种和分类群的各种适应特征中得到证实，然而，其突变基础尚不清楚。我们通过对 37 个个体的全基因组进行重新测序，来研究假定的有害变异如何影响适应能力，以及个体的遗传背景如何对其产生影响。这些个体生活在北极狐（Vulpes lagopus）自然种群中，既受到近亲繁殖衰退的影响，也受到遗传拯救的影响。我们发现，与具有较低 LoF 比例的个体相比，具有高比例纯合功能丧失基因型（LoFs）的个体，其预期对适应能力有较强影响，其终生繁殖成功率通常较低，寿命也较短。我们还发现，幼体存活率与纯合错义基因型的比例呈负相关，与全基因组杂合度呈正相关。我们的研究结果表明，强和中度有害突变的纯合性可能是野生种群中特定性状近亲繁殖衰退的一个重要原因，并朝着使用应用保护遗传学做出更明智的决策迈出了重要一步。
