An evaluation of the suitability of COI and COII gene variation for reconstructing the phylogeny of, and identifying cryptic species in, anopheline mosquitoes (Diptera Culicidae)

Abstract

Abstract We assessed the practicality and effectiveness of using variation in the mitochondrial COI and COII genes to discriminate species and reconstruct the phylogeny of anophelene mosquitoes. Phylogenetic relationships among the subfamily Anophelinae were inferred from portions of the mitochondrial COI (92 species) and COII genes (108 species). Phylogenetic trees were reconstructed on the basis of parsimony, maximum likelihood and Bayesian methods. The suitability of COI and COII gene variation for identifying cryptic species was compared by comparing the sequence divergence within species groups and complexes. The results show that the COI gene was more useful for identifying sibling and cryptic species, but that phylogenetic relationships reconstructed using the COII gene were more similar to those based on morphological data. We conclude that: (1) there is a significant molecular divergence among An. sinensis; (2) the COI and COII are valid genetic markers for resolving taxonomic relationships among anopheline mosquitoes and the resultant phylogeny raises some questions about the taxonomic status of anopheline species groups and complexes; (3) the genus Anopheles is not demonstrably monophyletic with regard to the genus Bironella; (4) the subgenera Kerteszia and Nyssorhynchus are monophyletic; (5) below the group-level, COI data support the existence of monophyletic taxa within the Anopheles funestus, Anopheles maculipennis and Anopheles strode and Anopheles barbirostris subgroups, and within the Anopheles nuneztovari complex, whereas COII data support the monophyletic taxa within the Anopheles minimus and Anopheles oswaldoi subgroups, and Anopheles hyrcanus group. The monophyletic taxa within the Anopheles gambiae and Anopheles albitarsis complexes are supported by both COI and COII data.