INSTITUTO DE DIVERSIDAD Y ECOLOGIA ANIMAL
Unidad Ejecutora - UE
Molecular identification of two Culex (Culex) species of the neotropical region (Diptera: Culicidae)
LAURITO, M.; ALMIRÓN, W.R.; AYALA, AM; GARDENAL, CN
PUBLIC LIBRARY SCIENCE
Lugar: San Francisco; Año: 2017 vol. 12
Culex bidens and C. interfor, implicated in arbovirus transmission in Argentina, are sisterspecies, only distinguishable by feature of the male genitalia; however, intermediate specimensof the species in sympatry have been found. Fourth-instar larvae and females of bothspecies share apomorphic features, and this lack of clear distinction creates problems forspecific identification. Geometric morphometric traits of these life stages also do not distinguishthe species. The aim of the present study was to assess the taxonomic status of C.bidens and C. interfor using two mitochondrial genes and to determine the degree of theirreproductive isolation using microsatellite loci. Sequences of the ND4 and COI genes wereconcatenated in a matrix of 993 nucleotides and used for phylogenetic and distance analyses.Bayesian and maximum parsimony inferences showed a well resolved and supportedtopology, enclosing sequences of individuals of C. bidens (0.83 BPP, 73 BSV) and C. interfor(0.98 BPP, 97 BSV) in a strong sister relationship. The mean K2P distance within C.bidens and C. interfor was 0.3% and 0.2%, respectively, and the interspecific variation was2.3%. Bayesian clustering also showed two distinct mitochondrial lineages. All sequencedmosquitoes were successfully identified in accordance with the best close match algorithm.The low genetic distance values obtained indicate that the species diverged quite recently.Most morphologically intermediate specimens of C. bidens from CoÂrdoba were heterozygousfor the microsatellite locus GT51; the significant heterozygote excess observed suggestsincomplete reproductive isolation. However, C. bidens and C. interfor should beconsidered good species: the ventral arm of the phallosome of the male genitalia and theND4 and COI sequences are diagnostic characters.