How a haemosporidian parasite of bats gets around: the genetic structure of a parasite, vector and host compared

Abstract

Parasite population structure is often thought to be largely shaped by that of its host. In the case of a parasite with a complex life cycle, two host species, each with their own patterns of demography and migration, spread the parasite. However, the population structure of the parasite is predicted to resemble only that of the most vagile host species. In this study, we tested this prediction in the context of a vector-transmitted parasite. We sampled the haemosporidian parasite Polychromophilus melanipherus across its European range, together with its bat fly vector Nycteribia schmidlii and its host, the bent-winged bat Miniopterus schreibersii. Based on microsatellite analyses, the wingless vector, and not the bat host, was identified as the least structured population and should therefore be considered the most vagile host. Genetic distance matrices were compared for all three species based on a mitochondrial DNA fragment. Both host and vector populations followed an isolation-by-distance pattern across the Mediterranean, but not the parasite. Mantel tests found no correlation between the parasite and either the host or vector populations. We therefore found no support for our hypothesis; the parasite population structure matched neither vector nor host. Instead, we propose a model where the parasite's gene flow is represented by the added effects of host and vector dispersal patterns.

Polychromophilus spp. (Haemosporida) in Malagasy bats: host specificity and insights on invertebrate vectors

“…The haplotypes of haemoparasites infecting Malagasy bats are embedded within the P. melanipherus clade occurring in African and European Miniopterus spp. This topology strongly supports a tight specificity of P. melanipherus within hosts belonging to the Miniopteridae [6, 17, 48]. One individual of P. furculus (Rhinonycteridae) also tested positive and based on the cyt b sequence, it fell within the P. melanipherus clade.…”

Parasitization of bats by bat flies (Streblidae) in fragmented habitats

“…However, the importance of parasites to affect host populations directly by controlling reproductive success, as well as their potential role as vectors for pathogens (Morse et al, ; Xu et al, ), is often neglected and severely understudied. While bat flies are known vectors of Polychromophilus blood parasites (Witsenburg et al, ), and bats react to infections with blood parasites with elevated white blood cell counts (Cottontail, Wellinghausen, & Kalko, ), consequences on bat health remain to be explored. With an ever increasing anthropogenic influence worldwide, it is important to understand how the interactions between hosts and their parasites respond to habitat changes, as here shown on the example of bats and their bat flies.…”

Host dispersal as the driver of parasite genetic structure: a paradigm lost?

“…wind or water currents) (Figuerola & Green ; Witsenburg et al . ). An important future research avenue will be to better identify the free‐living dispersive stages of parasite species, and to test to what extent they contribute to congruence (and incongruence) in host and parasite patterns of genetic differentiation.…”