Parasite infections can have substantial impacts on population dynamics and are accordingly a key challenge for wild population management. Here we studied genetic mechanisms driving parasite resistance in a large herbivore through a comprehensive approach combining measurements of neutral (16 microsatellites) and adaptive (MHC DRB1 exon 2) genetic diversity and two types of gastrointestinal parasites (nematodes and coccidia). While accounting for other extrinsic and intrinsic predictors known to impact parasite load, we show that both neutral genetic diversity and DRB1 are associated with resistance to gastrointestinal nematodes. Intermediate levels of multi-locus heterozygosity maximized nematodes resistance, suggesting that both in- and outbreeding depression might occur in the population. DRB1 heterozygosity and specific alleles effects were detected, suggesting the occurrence of heterozygote advantage, rare-allele effects and/or fluctuating selection. On the contrary, no association was detected between genetic diversity and resistance to coccidia, indicating that different parasite classes are impacted by different genetic drivers. This study provides important insights for large herbivores and wild sheep pathogen management, and in particular suggests that factors likely to impact genetic diversity and allelic frequencies, including global changes, are also expected to impact parasite resistance.

中文翻译：

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候选基因和中性遗传多样性均与雌性地中海uf鼠的寄生虫抗性相关

寄生虫感染可对种群动态产生重大影响，因此是野生种群管理的关键挑战。在这里，我们通过综合测量中性（16个微卫星）和适应性（MHC DRB1外显子2）遗传多样性以及两种胃肠道寄生虫（线虫和球菌）的方法，研究了驱动大型草食动物寄生虫抗性的遗传机制。虽然考虑到其他已知会影响寄生虫负荷的外在和内在预测因素，但我们显示中性遗传多样性和DRB1均与胃肠道线虫的抗性相关。中间水平的多位点杂合性使线虫的抗性最大化，这表明近亲和近亲抑郁都可能在种群中发生。检测到DRB1杂合性和特定等位基因效应，表明杂合子优势，稀有等位基因效应和/或波动选择的发生。相反，在遗传多样性和对球菌的抗性之间未发现关联，表明不同的寄生虫种类受不同的遗传驱动因素影响。这项研究为大型食草动物和野绵羊病原体的管理提供了重要的见识，特别是表明，可能影响遗传多样性和等位基因频率的因素，包括全球变化，也有望影响寄生虫抗性。表明不同的寄生虫种类受不同的遗传驱动因素影响。这项研究为大型食草动物和野绵羊病原体的管理提供了重要的见识，特别是表明，可能影响遗传多样性和等位基因频率的因素，包括全球变化，也有望影响寄生虫抗性。表明不同的寄生虫种类受不同的遗传驱动因素影响。这项研究为大型食草动物和野绵羊病原体的管理提供了重要的见识，特别是表明，可能影响遗传多样性和等位基因频率的因素，包括全球变化，也有望影响寄生虫抗性。