title: Pattern of association between endemic Hawaiian fruit flies (Diptera, Tephritidae) and their symbiotic bacteria: Evidence of cospeciation events and proposal of "Candidatus Stammerula trupaneae".
abstract: Several insect lineages have evolved mutualistic association with symbiotic bacteria. This is the case of some species of mealybugs, whiteflies, weevils, tsetse flies, cockroaches, termites, carpenter ants, aphids and fruit flies. Some species of Tephritinae, the most specialized subfamily of fruit flies (Diptera: Tephritidae), harbour co-evolved vertically transmitted, bacterial symbionts in their midgut, known as "Candidatus Stammerula spp.". The 25 described endemic species of Hawaiian tephritids, plus at least three undescribed species, are taxonomically distributed among three genera: the cosmopolitan genus Trupanea (21 described spp.), the endemic genus Phaeogramma (2 spp.) and the Nearctic genus Neotephritis (2 spp.). We examined the presence of symbiotic bacteria in the endemic tephritids of the Hawaiian Islands, which represent a spectacular example of adaptive radiation, and tested the concordant evolution between host and symbiont phylogenies. We detected through PCR assays the presence of specific symbiotic bacteria, designated as "Candidatus Stammerula trupaneae", from 35 individuals of 15 species. The phylogeny of the insect host was reconstructed based on two regions of the mitochondrial DNA (16S rDNA and COI-tRNALeu-COII), while the bacterial 16S rRNA was used for the symbiont analysis. Host and symbiont phylogenies were then compared and evaluated for patterns of cophylogeny and strict cospeciation. Topological congruence between Hawaiian Tephritinae and their symbiotic bacteria phylogenies suggests a limited, but significant degree of host-symbiont cospeciation. We also explored the character reconstruction of three host traits, as island location, host lineage, and host tissue attacked, based on the symbiont phylogenies under the hypothesis of cospeciation.
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova - Agripolis, Viale dell'Università, 16, 35020 Legnaro, Padova, Italy. Electronic address: elisabetta.viale@studenti.unipd.it.
authors.forename: E
authors.initials: E
authors.lastname: Viale
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova - Agripolis, Viale dell'Università, 16, 35020 Legnaro, Padova, Italy. Electronic address: isabel.martinez@unipd.it.
authors.forename: I
authors.initials: I
authors.lastname: Martinez-Sañudo
authors.affiliation: Department of Biology, Grinnell College, Grinnell, IA 50012, USA. Electronic address: brownj@grinnell.edu.
authors.forename: J M
authors.initials: JM
authors.lastname: Brown
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova - Agripolis, Viale dell'Università, 16, 35020 Legnaro, Padova, Italy. Electronic address: mauro.simonato@unipd.it.
authors.forename: M
authors.initials: M
authors.lastname: Simonato
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova - Agripolis, Viale dell'Università, 16, 35020 Legnaro, Padova, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Girolami
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova - Agripolis, Viale dell'Università, 16, 35020 Legnaro, Padova, Italy. Electronic address: squart@unipd.it.
authors.forename: A
authors.initials: A
authors.lastname: Squartini
authors.affiliation: Bayer Crop Science LP, R&D Trait Research, 3500 Paramount Parkway, Morrisville, NC 27560, USA. Electronic address: alberto.bressan@bayer.com.
authors.forename: A
authors.initials: A
authors.lastname: Bressan
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova - Agripolis, Viale dell'Università, 16, 35020 Legnaro, Padova, Italy. Electronic address: massimo.faccoli@unipd.it.
authors.forename: M
authors.initials: M
authors.lastname: Faccoli
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova - Agripolis, Viale dell'Università, 16, 35020 Legnaro, Padova, Italy. Electronic address: lmazzon@unipd.it.
authors.forename: L
authors.initials: L
authors.lastname: Mazzon
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification* / Q000235:genetics; D005075:Biological Evolution; D004269:DNA, Bacterial / Q000032:analysis; D004272:DNA, Mitochondrial / Q000032:analysis; D006254:Hawaii; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000032:analysis / Q000235:genetics; D017422:Sequence Analysis, DNA; D013559:Symbiosis; D033621:Tephritidae / Q000145:classification* / Q000235:genetics / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial; D004272:DNA, Mitochondrial; D012336:RNA, Ribosomal, 16S
keywords: Candidatus Stammerula; Cospeciation; Endosymbiosis; Fruit fly; Hawaiian Tephritinae