title: Host generalists and specialists emerging side by side: an analysis of evolutionary patterns in the cosmopolitan chewing louse genus Menacanthus.
abstract: Parasites with wide host spectra provide opportunities to study the ecological parameters of speciation, as well as the process of the evolution of host specificity. The speciose and cosmopolitan louse genus Menacanthus comprises both multi-host and specialised species, allowing exploration of the ecological and historical factors affecting the evolution of parasites using a comparative approach. We used phylogenetic analysis to reconstruct evolutionary relationships in 14 species of Menacanthus based on the sequences of one mitochondrial and one nuclear gene. The results allowed us to validate species identification based on morphology, as well as to explore host distribution by assumed generalist and specialist species. Our analyses confirmed a narrow host use for several species, however in some cases, the supposed host specialists had a wider host spectrum than anticipated. In one case a host generalist (Menacanthus eurysternus) was clustered terminally on a clade almost exclusively containing host specialists. Such a clade topology indicates that the process of host specialisation may not be irreversible in parasite evolution. Finally, we compared patterns of population genetic structure, geographic distribution and host spectra between two selected species, M. eurysternus and Menacanthus camelinus, using haplotype networks. Menacanthus camelinus showed limited geographical distribution in combination with monoxenous host use, whereas M. eurysternus showed a global distribution and lack of host specificity. It is suggested that frequent host switching maintains gene flow between M. eurysternus populations on unrelated hosts in local populations. However, gene flow between geographically distant localities was restricted, suggesting that geography rather than host-specificity is the main factor defining the global genetic diversity of M. eurysternus.
authors.affiliation: Faculty of Science, University of South Bohemia and Biology Centre ASCR, Institute of Parasitology, Branisovska 31, 37005 Ceske Budejovice, Czech Republic. Electronic address: martinu@paru.cas.cz.
authors.forename: Jana
authors.initials: J
authors.lastname: Martinů
authors.affiliation: Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho tr. 1/3, 61242 Brno, Czech Republic.
authors.forename: Oldřich
authors.initials: O
authors.lastname: Sychra
authors.affiliation: Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho tr. 1/3, 61242 Brno, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Literák
authors.affiliation: Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, v.v.i., Kvetna 8, 60365 Brno, Czech Republic.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Čapek
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Gustafsson
authors.affiliation: Faculty of Science, University of South Bohemia and Biology Centre ASCR, Institute of Parasitology, Branisovska 31, 37005 Ceske Budejovice, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Štefka
mesh_terms: D000220:Adaptation, Biological; D058325:Amblycera / Q000145:classification* / Q000235:genetics* / Q000502:physiology; D000818:Animals; D005075:Biological Evolution; D051456:Gene Flow; D058507:Host Specificity; D008969:Molecular Sequence Data; D058974:Phylogeography; D017422:Sequence Analysis, DNA
keywords: Generalist; Geographic distribution; Host specificity; Menacanthus; Population structure; Specialist