Relações morfométricas e genética populacional de Culex quinquefasciatus (Diptera: Culicidae) / Morphometric relationships and population genetics of Culex quinquefasciatus




Objective. The Culex (Culex) quinquefasciatus Say 1823 is widely distributed in human settlements, and is a vector in the transmission cycles of pathogens such as arboviruses and filarids. This species belongs to Cx pipiens complex, whose main characteristic is the morphologic similarity of their species. This study aimed to characterize genetic and morphological Cx quinquefasciatus species from different regions of Brazil and La Plata, Argentina. Methods. Were used morphometric values of wing veins of females and the DV/D ratio of aedeagus in adult male genitalia. For genetic testing were sequenced mitochondrial cox1 and nd4 genes, cloned fragments of ribosomal ITS2 spacer and examined the pattern of electrophoretic bands of the second intron of Acetylcholinesterase (ace2) locus. Results. The shape of the wing veins of female aggregates two main groups, one with mosquitoes of the Brazil and one from La Plata, the latter having greater internal variance. These data are related to the distribution found in ace2 fragment, which indicates La Plata as hybridization area between Cx. pipiens and Cx. quinquefasciatus. The values of wing size form a geographical cline, with three main groupings. One of these areas in the north of Brazil other in the southeast and south, and another in Argentina. The same happens with reason DV/D of the male genitalia. Sequence data bases have cox1 gene polymorphisms with low diversity and clustering of population in southern Brazil. The cox1 SNPs found are trace, because it does not show modification in the structure of the protein produced. The nd4 gene is identical in all samples. These fragments suggest homoplasmic features in Cx. quinquefasciatus. ITS2 showed polymorphisms and intragenomic events by insertion, deletion, translocation and transition bases. However, these events are synchronous in populations from different geographic areas and shows little variation in the structures of rRNA transcripts. Moreover, the data indicate ITS2 segregation of a trinucleotide GTC in mosquitoes from La Plata, featuring this area as the geographic isolation of the subgroup pipiens mosquitoes. Conclusion. Cx quinquefasciatus species has low genetic and morphological diversity, two mitochondrial lineages in Brazil and mosquitoes of hybrid origin with Cx pipiens in La Plata, Argentina


ace2 ace2 cox1 cox1 culex quinquefasciatus culex quinquefasciatus its2 its2 morfometria morphometry nd4 nd4

Documentos Relacionados