Neotropical Anopheles triannulatus complex: phylogeography and demographic history based on mitochondrial and nuclear markers

MORENO M, HARLOW W, HILDEBRANDT J, FERNANDES SILVA-DO-NASCIMENTO T, SALLUM MAM, FRITZ G, WILKERSON R, RUIZ JF, LOAIZA J, POVOA MM, DANTUR MJ, CORREA MM, GUTIERREZ-BUILES LA, CONN JE.

Washington

Congreso; 58th Annual Meeting of the American Society for Tropical Medicine and Hygiene.; 2009

American Society of Tropical Medicine and Hygiene

Anopheles triannulatus is a complex of at least three sibling species: An. triannulatus sensu strictu, An. halophylus and An. triannulatus “C”.  Anopheles triannulatus s.l. has been incriminated as a malaria vector in some South American countries, especially when it occurs in high densities. Morphological and behavioral differences, such as larval habitat exploitation, have been described. In addition, molecular analysis using isoenzymes detected a barrier to gene flow among the three sympatric species. To decipher the evolutionary forces that may have led to the current distribution and genetic history of members of Anopheles triannulatus s.l., we analyzed the mitochondrial COI and the nuclear white gene in mosquitoes from 7 countries and 15 different locations, including samples of sympatric An. halophylus and An. triannulatus ”C” from Salobra, (SW Brazil). The median joining network based on the COI gene depicted the haplotypes grouping in 7 different lineages with a high number of mutational steps between them, a) Panamanian, Colombian and Venezuelan, b)  Venezuelan c) N and NE Brazilian, d) Ecuadorian, e) NW Colombian, f) SE Brazilian g) Bolivian, Argentinian and Central Brazilian (including here An.halophylus and An triannulatus ”C”). In contrast, statistical parsimony analysis of white gene showed 4 different clusters, 1) Panamanian, Venezuelan, Colombian and NE Brazilian (except Ceará), 2) Venezuelan, Ecuadorian and SW Brazilian 3) An. halophylus and An. triannulatus “C” plus SW Brazilian, 4) NE Brazilian (Ceará). Signatures of population expansion were detected with the COI gene in NE Brazil, Venezuela (Casigua), Panama (Gamboa) and Colombia (Moñitos). Estimated time of expansion was during the Pleistocene. Results of Bayesian Inference support network lineages, with stronger posterior probabilities in the white gene. Neither marker supports monophyly of any of the three taxa. Both markers detected Casigua, (Venezuela), as an area where lineages converge, supporting the idea of a hotspot for diversity perhaps as a consequence of repeated Andean uplifts.