Toward understanding Anophelinae (Diptera, Culicidae) phylogeny: Insights from nuclear single-copy genes and the weight of evidence

A phylogeny of the mosquito subfamily Anophelinae was inferred from fragmen ts of two protein-coding nuclear genes, G(6)pd (462 bp) and white (801 bp), and from a combined data set (2,136 bp) that included a portion of the mit ochondrial gene ND5 and the D2 region of the ribosomal 28S gene. Sixteen sp ecies from all three anopheline genera and six Anopheles subgenera were sam pled, along with six species of other mosquitoes used as an outgroup. Each of four genes analyzed individually recovered the same well-supported clade s; topological incongruence was limited to unsupported or poorly supported nodes. As assessed by the incongruence length difference test, most of the conflicting signal was contributed by third codon positions. Strong structu ral constraints, as observed in white and G6pd, apparently had little impac t on phylogenetic inference. Compared with the other genes, white provided a superior source of phylogenetic information. However, white appears to ha ve experienced accelerated rates of evolution in few lineages, the affiniti es of which are therefore suspect. In combined analyses, most of the inferr ed relationships were well-supported and in agreement with previous studies : monophyly of Anophelinae, basal position of Chagasia, monophyly of Anophe les subgenera, and subgenera Nyssorhynchus + Kerteszia as sister taxa. The results suggested also monophyletic origin of subgenera Cellia + Anopheles, and the white gene analysis supported genus Bironella as a sister taxon to Anopheles. The present data and other available evidence suggest a South A merican origin of Anophelinae, probably in the Mesozoic; a rapid diversific ation of Bironella and basal subgeneric lineages of Anopheles, potentially associated with the breakup of Gondwanaland; and a relatively recent and ra pid dispersion of subgenus Anopheles.