title: Phylogeographic analyses of bacterial endosymbionts in fig homotomids (Hemiptera: Psylloidea) reveal codiversification of both primary and secondary endosymbionts.
abstract: While obligate primary (P-) endosymbionts usually cospeciate with their insect hosts, less is known about codiversification of secondary (S-) endosymbionts that are generally considered facultative. Typically, insects of the superfamily Psylloidea harbour one P- (Carsonella) and at least one S-endosymbiont, thought to compensate for Carsonella genome reduction. Most codiversification studies have used phylogenies of psyllids and their endosymbionts across and within host families or genera, but few have explored patterns within species. We focussed on P- and S-endosymbionts of three Mycopsylla (Homotomidae) species to explore whether they have congruent phylogenies and within-species geographic structures. The P-endosymbiont Carsonella, a S-endosymbiont and Wolbachia all had 100% prevalence, while Arsenophonus was only found in one species at low prevalence. Congruent phylogenies of Mycopsylla and P-endosymbionts across populations and species support strict cospeciation. S-endosymbiont phylogenies were also congruent across host species but low genetic variation in the S-endosymbiont was not correlated with host phylogeography, possibly due to a shorter evolutionary association. Between species, Wolbachia and Mycopsylla phylogenies were incongruent, probably due to horizontal transmission events. Our study is the first to explore endosymbionts of Mycopsylla and further supports the codivergence of Psylloidea hosts and P-endosymbionts, with obligate host interactions for both P- and S-endosymbionts.
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia c.fromont@westernsydney.edu.au.
authors.forename: Caroline
authors.initials: C
authors.lastname: Fromont
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia.
authors.forename: Markus
authors.initials: M
authors.lastname: Riegler
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia.
authors.forename: James M
authors.initials: JM
authors.lastname: Cook
mesh_terms: D000818:Animals; D001482:Base Composition / Q000235:genetics; D005075:Biological Evolution; D004272:DNA, Mitochondrial / Q000235:genetics; D004755:Enterobacteriaceae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D019143:Evolution, Molecular; D030681:Ficus; D044129:Halomonadaceae / Q000235:genetics / Q000302:isolation & purification*; D006430:Hemiptera / Q000382:microbiology*; D010802:Phylogeny; D058974:Phylogeography; D013559:Symbiosis / Q000235:genetics*; D020577:Wolbachia / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004272:DNA, Mitochondrial
keywords: co-evolution; endosymbiont; homotomid; phylogeny; phylogeography; psyllid