Microsatellite and mitochondrial markers reveal strong gene flow barriers for Anopheles farauti in the Solomon Archipelago: implications for malaria vector control.
Anopheles farauti is the primary malaria vector throughout the coastal regions of the Southwest Pacific. A shift in peak biting time from late to early in the night occurred following widespread indoor residue spraying of dichlorodiphenyltrichloro-ethane (DDT) and has persisted in some island populations despite the intervention ending decades ago. We used mitochondrial cytochrome oxidase I (COI) sequence data and 12 newly developed microsatellite markers to assess the population genetic structure of this malaria vector in the Solomon Archipelago. With geographically distinct differences in peak A. farauti night biting time observed in the Solomon Archipelago, we tested the hypothesis that strong barriers to gene flow exist in this region. Significant and often large fixation index (FST) values were found between different island populations for the mitochondrial and nuclear markers, suggesting highly restricted gene flow between islands. Some discordance in the location and strength of genetic breaks was observed between the mitochondrial and microsatellite markers. Since early night biting A. farauti individuals occur naturally in all populations, the strong gene flow barriers that we have identified in the Solomon Archipelago lend weight to the hypothesis that the shifts in peak biting time from late to early night have appeared independently in these disconnected island populations. For this reason, we suggest that insecticide impregnated bed nets and indoor residue spraying are unlikely to be effective as control tools against A. farauti occurring elsewhere, and if used, will probably result in peak biting time behavioural shifts similar to that observed in the Solomon Islands.
School of Biological Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
Luke
L
Ambrose
Australian Army Malaria Institute, Brisbane, Queensland 4051, Australia.
Robert D
RD
Cooper
Queensland Tropical Health Alliance, James Cook University, Cairns, Australia.
Tanya L
TL
Russell
Queensland Tropical Health Alliance, James Cook University, Cairns, Australia.
Thomas R
TR
Burkot
Eck Institute for Global Health, University of Notre Dame, IN, USA.
Neil F
NF
Lobo
Eck Institute for Global Health, University of Notre Dame, IN, USA.
Frank H
FH
Collins
Taman Damai, Jalan Fung Yei Teing, Kota Kinabalu, Sabah, Malaysia.
Jeffrey
J
Hii
School of Biological Sciences, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia; CSIRO Ecosystem Sciences, Boggo Rd, Dutton Park, Queensland 4102, Australia. Electronic address: n.beebe@uq.edu.au.
Nigel W
NW
Beebe
D000818:Animals; D000852:Anopheles / Q000235:genetics* / Q000469:parasitology*; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D017344:Genes, Insect; D005828:Genetics, Population; D006801:Humans; D007300:Insect Control / Q000379:methods; D007303:Insect Vectors / Q000235:genetics* / Q000469:parasitology*; D008288:Malaria / Q000517:prevention & control* / Q000635:transmission*; D008542:Melanesia; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D058974:Phylogeography
D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV
Anopheles farauti; Behavioural insecticide resistance; Mosquito behaviour; Population genetics; Selection; Sex-biased dispersal