Comparative analysis of landscape effects on spatial genetic structure of the big brown bat and one of its cimicid ectoparasites

Abstract

Identification of landscape features that correlate with genetic structure permits understanding of factors that may influence gene flow in a species. Comparing effects of the landscape on a parasite and host provides potential insights into parasite‐host ecology. We compared fine‐scale spatial genetic structure between big brown bats (Eptesicus fuscus) and their cimicid ectoparasite (Cimex adjunctus; class Insecta) in the lower Great Lakes region of the United States, in an area of about 160,000 km2. We genotyped 142 big brown bat and 55 C. adjunctus samples at eight and seven microsatellite loci, respectively, and inferred effects of various types of land cover on the genetic structure of each species. We found significant associations between several land cover types and genetic distance in both species, although different land cover types were influential in each. Our results suggest that even in a parasite that is almost entirely reliant on its hosts for dispersal, land cover can affect gene flow differently than in the hosts, depending on key ecological aspects of both species.

Comparative landscape genetics reveals differential effects of environment on host and pathogen genetic structure in Tasmanian devils (Sarcophilus harrisii) and their transmissible tumour

“…However, pathogen genetic structure does not necessarily reflect that of the host, and pathogen transmission may be disconnected from patterns of host gene flow. Such a disconnect may be due to factors including multiple host/ vector species, pathogen persistence in environmental reservoirs, transmission via nonreproducing hosts or host life history characteristics resulting in reduced susceptibility at dispersal age (Mazé-Guilmo, Blanchet, Mccoy, & Loot, 2016;Talbot, Vonhof, Broders, Fenton, & Keyghobadi, 2017). Therefore, comparative approaches, ideally incorporating the relative influence of environmental or ecological factors, are necessary for understanding the extent to which host and pathogen genetic structure are related and to disentangle the factors influencing each.…”

“…Even fewer multispecies studies have employed landscape genetics methods to study the dynamics of infectious diseases in wildlife systems (Biek & Real, 2010;Hemming-Schroeder et al, 2018;Kozakiewicz et al, 2018). Such comparative landscape genetics frameworks can provide valuable insights into how host-pathogen interactions shape patterns of disease transmission and spread across heterogeneous landscapes (Leo, Gonzalez, Millien, & Cristescu, 2016;Schwabl et al, 2017;Talbot et al, 2017).…”

Nuclear genetic diversity of head lice sheds light on human dispersal around the world

“…In addition, because parasites have larger population sizes and faster rates of molecular evolution compared to their hosts, population genetic patterns of parasites can reveal life history traits of their host such as host dispersal, interspecies interactions and population structure that might not be evident from host data alone or not yet discernible in the host's genome [9,72,73]. Differences between parasite and host intrinsic life-history traits may lead to incongruities in patterns of population structure between hosts and their parasites [74][75][76][77][78]. Several types of parasites are known to demonstrate this phenomenon, including flies from bats [78], helminths from pikas [79],…”

Nuclear genetic diversity of head lice sheds light on human dispersal around the world

“…These host aspects might not be evident using the host data alone or not yet discernible in the host's genome [9,93,94]. Differences between parasite and host intrinsic life-history traits may lead to incongruities in patterns of population structure between hosts and their parasites [95][96][97][98][99]. This phenomenon has been observed amongst several parasites including flies [99], helminths [100], and feather lice [101].…”