Analysis of the evolutionary forces shaping mitochondrial genomes of a Neotropical malaria vector complex

• Published in: Molecular phylogenetics and evolution 2011-03, Vol.58 (3), p.469-477
• Main Authors: Krzywinski, Jaroslaw, Li, Cong, Morris, Marion, Conn, Jan E., Lima, José B., Povoa, Marinete M., Wilkerson, Richard C.
• Format: Article
• Language: English
• Subjects: Animals; Anopheles - classification; Anopheles - genetics; Anopheles albitarsis; Asymmetry; Comparative genomics; Deoxyribonucleic acid; Disease Vectors; DNA, Mitochondrial - genetics; Evolution; Evolution, Molecular; Evolutionary; Genes; Genome, Insect; Genome, Mitochondrial; Genomes; Genomics; humans; introgression; Introgressive hybridization; Malaria; Malaria vectors; Mathematical analysis; mitochondrial DNA; Mitochondrial genome evolution; Mutation; phylogeny; population genetics; Replication origin; RNA; Selection, Genetic; Sequence Analysis, DNA; Species Specificity; tropics; Vectors (mathematics)
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2011.01.003

[Display omitted] ► Complete mtDNA genomes reported for six species of the Anopheles albitarsis complex. ► mtDNA evolution driven by directional mutation pressure and purifying selection. ► Signature of a potential ancient mtDNA introgression found. ► Potential mechanism of mtDNA replication in Anopheles uncovered. ► Support for existence of a new species within the complex. Many vectors of human malaria belong to complexes of morphologically indistinguishable cryptic species. Here we report the analysis of the newly sequenced complete mitochondrial DNA molecules from six recognized or putative species of one such group, the Neotropical Anopheles albitarsis complex. The molecular evolution of these genomes had been driven by purifying selection, particularly strongly acting on the RNA genes. Directional mutation pressure associated with the strand-asynchronous asymmetric mtDNA replication mechanism may have shaped a pronounced DNA strand asymmetry in the nucleotide composition in these and other Anopheles species. The distribution of sequence polymorphism, coupled with the conflicting phylogenetic trees inferred from the mitochondrial DNA and from the published white gene fragment sequences, indicates that the evolution of the complex may have involved ancient mtDNA introgression. Six protein coding genes (nad5, nad4, cox3, atp6, cox1 and nad2) have high levels of sequence divergence and are likely informative for population genetics studies. Finally, the extent of the mitochondrial DNA variation within the complex supports the notion that the complex consists of a larger number of species than until recently believed.