Biogeography and host-related factors trumps parasite life-history: limited congruence among the genetic structures of specific ectoparasitic lice and their rodent hosts

Parasites and hosts interact across both micro- and macroevolutionary scales where congruence among their phylogeographic and phylogenetic structures may be observed. Within southern Africa, the four-striped mouse genus, Rhabdomys, is parasitized by the ectoparasitic sucking louse, Polyplax arvicanthis. Molecular data recently suggested the presence of two cryptic species within P. arvicanthis that are sympatrically distributed across the distributions of four putative Rhabdomys species. We tested the hypotheses of phylogeographic congruence and cophylogeny among the two parasite lineages and the four host taxa, utilizing mitochondrial and nuclear sequence data. Despite the documented host-specificity of P. arvicanthis, limited phylogeographic correspondence and nonsignificant cophylogeny was observed. Instead, the parasite–host evolutionary history is characterized by limited codivergence and several duplication, sorting and host-switching events. Despite the elevated mutational rates ...

寄生虫与宿主的相互作用贯穿微观演化与宏观演化两个尺度，二者的系统地理学结构与系统发育结构往往呈现一致性。在南非南部地区，四纹鼠属（Rhabdomys）的物种会被外寄生吸虱阿维坎特吸虱（Polyplax arvicanthis）寄生。近期的分子数据显示，阿维坎特吸虱内部存在两个隐存种，这两个隐存种的分布范围与四种推定的四纹鼠属物种的分布范围重叠。本研究利用线粒体基因与核基因序列数据，对这两种吸虱支系与四种四纹鼠属宿主类群之间的系统地理一致性和共系统发育假说进行了检验。尽管已有研究证实阿维坎特吸虱具有宿主特异性，但本研究仅观察到有限的系统地理对应关系，且共系统发育关系并不显著。与之相反，该吸虱与宿主的演化历史以有限的共分化事件，以及多次复制、分选与宿主转换事件为核心特征。尽管突变率升高……