Mitochondrial DNA analysis of the neotropical malaria vectorAnopheles nuneztovari

Abstract

Restriction endonucleases were used to test an hypothesis, based on cytological data, proposing the existence of two races in Anopheles nuneztovari, one Venezuelan-Colombian and the other Amazonian, and to examine variation in the mitochondrial DNA (mtDNA) of 263 individual A. nuneztovari mosquitoes from 12 sites in Bolivia, Brazil, Colombia, Suriname, and Venezuela. Cladistic analysis of the mtDNA data using three outgroups suggests that A. nuneztovari is monophyletic. However, this analysis is poorly resolved by parsimony, probably caused by extensive homoplasy. Analysis of the relationships among haplotypes, based on genetic distances, results in five haplotype lineages, three of which are in the Amazon Basin. Relationships among the 12 populations reveal distinctive lineages, one in Venezuela-Colombia and two within the Amazon Basin. Molecular variance components and F statistics (phi) among neotropical biomes, among populations/biomes, among cytotypes, among populations/cytotypes, and within populations all demonstrate significant subdivision and strongly support multiple lineages, which could be interpreted as recently evolved species, within A. nuneztovari. The Mantel analysis showed no significant correlation between genetic and geographic distances, suggesting that it is biomes and cytotypes that contribute most strongly to subdivision.Key words: mtDNA lineages, anopheline mosquito, gene flow, genetic diversity, neotropical.

Mitochondrial DNA Detects a Complex Evolutionary History with Pleistocene Epoch Divergence for the Neotropical Malaria Vector Anopheles nuneztovari Sensu Lato

“…Unlike earlier studies that detected higher levels of differentiation between Amazon Basin and Colombia/Venezuela populations, [18][19][20][21][22][23][24][25][26][27][28] our results identified the deepest divergence and earliest divergence time between clade I and subclade II-B, both within the Amazon Basin. These discrepant results could have been caused by more localities from the central Amazonian Brazil being sampled in the present study.…”

“…24,25,28 In this study, intra-population diversity measures were fairly high in An. nuneztovari s.l., as detected in a previous study in this species, 26 and in other anophelines. [61][62][63] The samples from the Amazon Basin tended to have higher genetic diversity, in particular nucleotide diversity, than those from Bolivia/ Colombia/Venezuela.…”

“…10 However, mosquitoes collected from the central Amazonian region have been mainly zoophagic and exophilic. 7 In the present study and in the study of Scarpassa and others, 27 samples from these two regions had no shared haplotypes and were recognized as distinct lineages by Conn and others, 26 which could indicate a barrier to gene flow. If this suggestion is correct, this finding may explain distinct behavioral patterns of these mosquitoes.…”

“…[18][19][20][21][22][23][24][25][26][27][28] Morphologic comparisons showed that the apex of the aedeagus is distinct between samples from the Amazon Basin and Colombia plus Venezuela. 3,18 These data combined with molecular analyses led to the resurrection of An.…”

“…19,20 Subsequently, morphologic, isoenzymatic, and molecular studies found significant differentiation between the two allopatric races, but no notable evidence to support a species complex. [21][22][23][24][25][26][27] However, within Amazonian Brazil, internal transcribed spacer 2 (ITS2) 22 and mitochondrial DNA (mtDNA)-restriction fragment length polymorphism (RFLP) 26 analyses indicated multiple lineages, and a lack of gene flow between the central and eastern regions. 27 A recent study using nuclear white gene sequences described five lineages in An.…”