Genetic composition can influence host susceptibility to, and transmission of, pathogens, with potential population‐level consequences. In bighorn sheep (Ovis canadensis), pneumonia epidemics caused by Mycoplasma ovipneumoniae have been associated with severe population declines and limited recovery across North America. Adult survivors either clear the infection or act as carriers that continually shed M. ovipneumoniae and expose their susceptible offspring, resulting in high rates of lamb mortality for years following the outbreak event. Here, we investigated the influence of genomic composition on persistent carriage of M. ovipneumoniae in a well‐studied bighorn sheep herd in the Wallowa Mountains of Oregon, USA. Using 10,605 SNPs generated using RADseq technology for 25 female bighorn sheep, we assessed genomic diversity metrics and employed family‐based genome‐wide association methodologies to understand variant association and genetic architecture underlying chronic carriage. We observed no differences among genome‐wide diversity metrics (heterozygosity and allelic richness) between groups. However, we identified two variant loci of interest and seven associated candidate genes, which may influence carriage status. Further, we found that the SNP panel explained ~55% of the phenotypic variance (SNP‐based heritability) for M. ovipneumoniae carriage, though there was considerable uncertainty in these estimates. While small sample sizes limit conclusions drawn here, our study represents one of the first to assess the genomic factors influencing chronic carriage of a pathogen in a wild population and lays a foundation for understanding genomic influence on pathogen persistence in bighorn sheep and other wildlife populations. Future research should incorporate additional individuals as well as distinct herds to further explore the genomic basis of chronic carriage.

中文翻译：

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大角羊（加拿大羊）的基因组学与病原体携带的关系

遗传组成会影响宿主对病原体的易感性和传播，并可能导致种群水平的后果。在大角羊（Ovis canadensis）中，由猪支原体支原体引起的肺炎流行与整个北美的种群严重减少和恢复有限有关。成年幸存者要么清除感染，要么充当携带者，使之继续脱落卵形支原体肺炎并暴露其易感后代，从而导致暴发事件后数年内羔羊死亡率很高。在这里，我们调查了基因组组成对卵形支原体持续运输的影响在美国俄勒冈州的沃洛纳山中，经过精心研究的大角羊群。我们使用RADseq技术为25只雌性大角羊生产了10,605个SNP，评估了基因组多样性指标，并采用了基于家族的全基因组关联方法，以了解长期运输背后的变异关联和遗传结构。我们没有观察到组之间全基因组多样性指标（杂合度和等位基因丰富度）之间没有差异。但是，我们确定了两个感兴趣的变异基因座和七个相关的候选基因，这可能会影响运输状态。此外，我们发现SNP小组解释了卵形支原体约占表型变异（基于SNP的遗传力）的55％运输，尽管这些估算存在很大的不确定性。尽管样本量少限制了此处得出的结论，但我们的研究代表了第一个评估影响野生种群中慢性病原体慢性携带的基因组因素之一，并为理解基因组对大角羊和其他野生动植物种群中病原体持久性的影响奠定了基础。未来的研究应纳入更多的个体以及不同的种群，以进一步探索慢性携带的基因组基础。