Bankers Laura, Fields Peter, McElroy Kyle E, Boore Jeffrey L, Logsdon John M, Neiman Maurine
Department of Biology, University of Iowa, Iowa City, IA, USA.
Zoologisches Institut, Universität Basel, Basel, Switzerland.
Mol Ecol. 2017 Jul;26(14):3663-3675. doi: 10.1111/mec.14146. Epub 2017 May 10.
Reciprocal co-evolving interactions between hosts and parasites are a primary source of strong selection that can promote rapid and often population- or genotype-specific evolutionary change. These host-parasite interactions are also a major source of disease. Despite their importance, very little is known about the genomic basis of co-evolving host-parasite interactions in natural populations, especially in animals. Here, we use gene expression and sequence evolution approaches to take critical steps towards characterizing the genomic basis of interactions between the freshwater snail Potamopyrgus antipodarum and its co-evolving sterilizing trematode parasite, Microphallus sp., a textbook example of natural coevolution. We found that Microphallus-infected P. antipodarum exhibit systematic downregulation of genes relative to uninfected P. antipodarum. The specific genes involved in parasite response differ markedly across lakes, consistent with a scenario where population-level co-evolution is leading to population-specific host-parasite interactions and evolutionary trajectories. We also used an F -based approach to identify a set of loci that represent promising candidates for targets of parasite-mediated selection across lakes as well as within each lake population. These results constitute the first genomic evidence for population-specific responses to co-evolving infection in the P. antipodarum-Microphallus interaction and provide new insights into the genomic basis of co-evolutionary interactions in nature.
宿主与寄生虫之间相互的协同进化相互作用是强大选择的主要来源，这种选择能够促进快速且通常是种群或基因型特异性的进化变化。这些宿主 - 寄生虫相互作用也是疾病的主要来源。尽管它们很重要，但对于自然种群中协同进化的宿主 - 寄生虫相互作用的基因组基础，尤其是在动物中，人们了解甚少。在这里，我们使用基因表达和序列进化方法，朝着表征淡水螺新西兰泥蜗及其协同进化的致不育吸虫寄生虫微小隐孢子虫之间相互作用的基因组基础迈出关键一步，微小隐孢子虫是自然协同进化的一个典型例子。我们发现，感染微小隐孢子虫的新西兰泥蜗相对于未感染的新西兰泥蜗表现出基因的系统性下调。不同湖泊中参与寄生虫反应的特定基因存在显著差异，这与种群水平的协同进化导致种群特异性宿主 - 寄生虫相互作用和进化轨迹的情况一致。我们还使用基于F统计量的方法来识别一组位点，这些位点代表了不同湖泊以及每个湖泊种群中寄生虫介导选择目标的有前景的候选位点。这些结果构成了新西兰泥蜗 - 微小隐孢子虫相互作用中对协同进化感染的种群特异性反应的首个基因组证据，并为自然界中协同进化相互作用的基因组基础提供了新的见解。
