School of Biological Sciences, University of East Anglia, Norfolk, UK.
Grupo Ecología y Evolución de Vertebrados, Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellín, Colombia.
Mol Ecol. 2022 Jun;31(11):3154-3173. doi: 10.1111/mec.16461. Epub 2022 Apr 18.
Understanding the mechanisms and genes that enable animal populations to adapt to pathogens is important from an evolutionary, health and conservation perspective. Berthelot's pipit (Anthus berthelotii) experiences extensive and consistent spatial heterogeneity in avian pox infection pressure across its range of island populations, thus providing an excellent system with which to examine how pathogen-mediated selection drives spatial variation in immunogenetic diversity. Here, we test for evidence of genetic variation associated with avian pox at both an individual and population-level. At the individual level, we find no evidence that variation in MHC class I and TLR4 (both known to be important in recognising viral infection) was associated with pox infection within two separate populations. However, using genotype-environment association (Bayenv) in conjunction with genome-wide (ddRAD-seq) data, we detected strong associations between population-level avian pox prevalence and allele frequencies of single nucleotide polymorphisms (SNPs) at a number of sites across the genome. These sites were located within genes involved in cellular stress signalling and immune responses, many of which have previously been associated with responses to viral infection in humans and other animals. Consequently, our analyses indicate that pathogen-mediated selection may play a role in shaping genomic variation among relatively recently colonised island bird populations and highlight the utility of genotype-environment associations for identifying candidate genes potentially involved in host-pathogen interactions.
从进化、健康和保护的角度来看，了解使动物种群能够适应病原体的机制和基因非常重要。伯特洛特氏石䳭（Anthus berthelotii）在其岛屿种群的范围内经历了广泛而一致的禽痘感染压力的空间异质性，因此为研究病原体介导的选择如何驱动免疫遗传多样性的空间变化提供了一个极好的系统。在这里，我们测试了个体和种群水平上与禽痘相关的遗传变异的证据。在个体水平上，我们没有发现 MHC 类 I 和 TLR4（两者都已知在识别病毒感染方面很重要）的变异与两个独立种群中的禽痘感染有关的证据。然而，我们使用基因型-环境关联（Bayenv）结合全基因组（ddRAD-seq）数据，检测到种群水平的禽痘患病率与基因组中许多位点的单核苷酸多态性（SNP）的等位基因频率之间存在强烈关联。这些位点位于细胞应激信号和免疫反应相关的基因内，其中许多基因先前与人类和其他动物对病毒感染的反应有关。因此，我们的分析表明，病原体介导的选择可能在塑造相对较近殖民岛屿鸟类种群的基因组变异方面发挥作用，并强调了基因型-环境关联在鉴定可能参与宿主-病原体相互作用的候选基因方面的效用。
