Codivergence in Heteromyid Rodents (Rodentia: Heteromyidae) and Their Sucking Lice of the Genus Fahrenholzia (Phthiraptera: Anoplura)

Abstract

Although most studies of codivergence rely primarily on topological comparisons of host and parasite phylogenies, temporal assessments are necessary to determine if divergence events in host and parasite trees occurred contemporaneously. A combination of cophylogenetic analyses and comparisons of branch lengths are used in this study to understand the host-parasite association between heteromyid rodents (Rodentia: Heteromyidae) and their sucking lice of the genus Fahrenholzia (Phthiraptera: Anoplura). Cophylogenetic comparisons based on nucleotide substitutions in the mitochondrial COI gene reveal a significant, but not perfect, pattern of cophylogeny between heteromyids and their sucking lice. Regression analyses show a significant functional relationship between the lengths of analogous branches in the host and parasite trees, indicating that divergence events in hosts and parasites were approximately contemporaneous. Thus, the topological similarity observed between heteromyids and their lice is the result of codivergence. These analyses also show that the COI gene in lice is evolving two to three times faster than the same gene in their hosts (similar to the results of studies of other lice and their vertebrate hosts) and that divergence events in lice occurred shortly after host divergence. We recommend that future studies of codivergence include temporal comparisons and, when possible, use the same molecular marker(s) in hosts and parasites to achieve the greatest insight into the history of the host-parasite relationship.

The sixth mass coextinction: are most endangered species parasites and mutualists?

“…Rezende et al 2007). In strict co-cladogenesis, for example, host and parasite (or mutualist and partner) phylogenies match identically or nearly so (Light & Hafner 2008). Additionally (and just as for hosts), the traits related to host specificity may be conserved phylogenetically, such that even if host extinction were phylogenetically random, affiliate extinction might not be.…”

Novel Primers From Informative Nuclear Loci for Louse Molecular Phylogenetics (Insecta: Phthiraptera)

“…Despite their importance as a model organism in hostÐparasite studies, very few loci have been targeted for sequencing in parasitic lice. A large number of studies have been published on the molecular phylogenetics of parasitic lice (Hafner et al 1994;Page et al 1998Page et al , 2004Cruickshank et al 2001;Johnson et al 2001aJohnson et al ,b, 2002aJohnson et al ,b, 2003Johnson et al , 2007Weckstein 2004;Banks et al 2005;Light and Hafner 2008;Š tefka and Hypsa 2008;Bueter et al 2009;Light et al 2010;Š tefka et al 2011), but most of these studies have only used short fragments of the mitochondrial cytochrome oxidase subunit-1 (CO1) and nuclear elongation factor-1 alpha (EF-1␣) for phylogenetic analysis. The generally small amount of data in these studies makes resolving many of the branches in the phylogenetic tree difÞcult.…”

Nematodes Associated With Mammals in the Great American Biotic Interchange (Gabi)

“…If cospeciation was the driving force of parasite diversification, one would expect that all mammals in a clade would be infected by parasites that are phylogenetically related, which is seldom the case (Light & Hafner 2008). The expectation of encountering mirroring or concordant phylogenies is based on two premises: (1) that species of permanent parasites are extremely host-specific, specializing in resources exclusively available on their host species; and (2) that parasites are able to transmit among potential hosts via contact and they are able to complete their life cycle without leaving the host body.…”