title: Phylogeography of the coastal mosquito Aedes togoi across climatic zones: testing an anthropogenic dispersal hypothesis.
abstract: The coastal mosquito Aedes togoi occurs more or less continuously from subarctic to subtropic zones along the coasts of the Japanese islands and the East Asian mainland. It occurs also in tropical Southeast Asia and the North American Pacific coast, and the populations there are thought to have been introduced from Japan by ship. To test this hypothesis, the genetic divergence among geographic populations of A. togoi was studied using one mitochondrial and three nuclear gene sequences. We detected 71 mitochondrial haplotypes forming four lineages, with high nucleotide diversity around temperate Japan and declining towards peripheral ranges. The major lineage (L1) comprised 57 haplotypes from temperate and subarctic zones in Japan and Southeast Asia including southern China and Taiwan. Two other lineages were found from subtropical islands (L3) and a subarctic area (L4) of Japan. The Canadian population showed one unique haplotype (L2) diverged from the other lineages. In the combined nuclear gene tree, individuals with mitochondrial L4 haplotypes diverged from those with the other mitochondrial haplotypes L1-L3; although individuals with L1-L3 haplotypes showed shallow divergences in the nuclear gene sequences, individuals from Southeast Asia and Canada each formed a monophyletic group. Overall, the genetic composition of the Southeast Asian populations was closely related to that of temperate Japanese populations, suggesting recent gene flow between these regions. The Canadian population might have originated from anthropogenic introduction from somewhere in Asia, but the possibility that it could have spread across the Beringian land bridge cannot be ruled out.
authors.affiliation: Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan.
authors.forename: Teiji
authors.initials: T
authors.lastname: Sota
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Belton
authors.affiliation: Department of Zoology, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Tseng
authors.affiliation: Institute of Biological Sciences, University of Malaya, Kuala Lumpur, 50603, Malaysia.
authors.forename: Hoi Sen
authors.initials: HS
authors.lastname: Yong
authors.affiliation: Division of Parasitology, Department of Pathology and Biodefense, Faculty of Medicine, Saga University, Saga, 849-8501, Japan.
authors.forename: Motoyoshi
authors.initials: M
authors.lastname: Mogi
mesh_terms: D000330:Aedes / Q000235:genetics*; D063147:Animal Distribution; D000818:Animals; D001499:Bayes Theorem; D002170:Canada; D002681:China; D002980:Climate; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D051456:Gene Flow; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006239:Haplotypes; D007564:Japan; D016013:Likelihood Functions; D058974:Phylogeography; D017422:Sequence Analysis, DNA; D013624:Taiwan
chemical_list: D004272:DNA, Mitochondrial