title: Phylogeography of Rhipicephalus sanguineus sensu lato and its relationships with climatic factors.
abstract: Brown dog ticks morphologically identifiable as Rhipicephalus sanguineus sensu lato, are distributed world-wide and their systematics is controversial. Results of genetic and reproductive compatibility studies of geographically distinct populations of R. sanguineus s.l. indicate that the R. sanguineus complex is paraphyletic. To further elucidate systematic relationships within R. sanguineus s.l. and geographic boundaries of its lineages, we conducted a phylogeographical study of 136 tick specimens from 23 countries. Voucher specimens were morphologically identified. A phylogenetic tree was constructed using concatenated partial mitochondrial 12S and 16S rDNA gene sequences and analyzed by the Neighbor-Joining method. A set of 19 bioclimatic variables within the WorldClim dataset were extracted and analyzed to assess correlations between distribution of R. sanguineus s.l. lineages and climatic variables. The following four branches are clearly recognized on the phylogenetic tree: R. sanguineus s.l.-tropical and temperate clades, R. leporis, and R. turanicus. DNA sequences of Rhipicephalus ticks from Israel differ from those of other groups. Strong association between geographical locations of major clades of R. sanguineus s.l. and temperature was identified. The tropical clade of R. sanguineus s.l. occupies areas with the annual mean temperature >20 °C, whereas the temperate clade is present in areas with the annual mean temperature <20 °C. Our results indicate that ticks in two closely related phylogenetic clades are adapted to different environmental conditions and support proposals for re-classification of R. sanguineus complex. Differences in R. sanguineus s.l. ecology and human/animal pathogens transmitted by different taxa of brown dog tick need to be studied.
authors.affiliation: Centers for Disease Control and Prevention, Rickettsial Zoonoses Branch, 1600 Clifton Road, MS G-13, Atlanta, GA, 30333, USA. GZemtsova@cdc.gov.
authors.forename: Galina E
authors.initials: GE
authors.lastname: Zemtsova
authors.affiliation: Institute for Coastal Plain Science, Georgia Southern University, Statesboro, GA, 30460, USA.
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Apanaskevich
authors.affiliation: USAF School of Aerospace Medicine/PHR, Wright-Patterson AFB, OH, 45433, USA.
authors.forename: Will K
authors.initials: WK
authors.lastname: Reeves
authors.affiliation: Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO, USA.|Research Applications Laboratory, National Center for Atmospheric Research, Boulder, CO, USA.
authors.forename: Micah
authors.initials: M
authors.lastname: Hahn
authors.affiliation: Centers for Disease Control and Prevention, Rickettsial Zoonoses Branch, 1600 Clifton Road, MS G-13, Atlanta, GA, 30333, USA.
authors.forename: Alyssa
authors.initials: A
authors.lastname: Snellgrove
authors.affiliation: Centers for Disease Control and Prevention, Rickettsial Zoonoses Branch, 1600 Clifton Road, MS G-13, Atlanta, GA, 30333, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Levin
mesh_terms: D000818:Animals; D002980:Climate; D014644:Genetic Variation; D010802:Phylogeny; D058974:Phylogeography; D012335:RNA, Ribosomal / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D048508:Rhipicephalus sanguineus / Q000145:classification / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D012335:RNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C075526:RNA, ribosomal, 12S
keywords: Climate variables; Genetic diversity; Phylogenetic analysis; Phylogeographic pattern; Rhipicephalus sanguineus