Genetic variability of Aedes aegypti in the Americas using a mitochondrial gene: evidence of multiple introductions.

Autor(es): Bracco José Eduardo; Capurro Margareth Lara; Lourenço-de-Oliveira Ricardo; Sallum Maria Anice Mureb

Resumo: To analyze the genetic relatedness and phylogeographic structure of Aedes aegypti, we collected samples from 36 localities throughout the Americas (Brazil, Peru, Venezuela, Guatemala, US), three from Africa (Guinea, Senegal, Uganda), and three from Asia (Singapore, Cambodia, Tahiti). Amplification and sequencing of a fragment of the mitochondrial NADH dehydrogenase subunit 4 gene identified 20 distinct haplotypes, of which 14 are exclusive to the Americas, four to African/Asian countries, one is common to the Americas and Africa, and one to the Americas and Asia. Nested clade analysis (NCA), pairwise distribution, statistical parsimony, and maximum parsimony analyses were used to infer evolutionary and historic processes, and to estimate phylogenetic relationships among haplotypes. Two clusters were found in all the analyses. Haplotypes clustered in the two clades were separated by eight mutational steps. Phylogeographic structure detected by the NCA was consistent with distant colonization within one clade and fragmentation followed by range expansion via long distance dispersal in the other. Three percent of nucleotide divergence between these two clades is suggestive of a gene pool division that may support the hypothesis of occurrence of two subspecies of Ae. aegypti in the Americas.

Imprenta: Memo?rias do Instituto Oswaldo Cruz, v. 102, n. 5, p. 573-580, 2007

Identificador do objeto digital:

Descritores: Aedes aegypti - DNA ; Aedes aegypti - Pathogenesis ; Aedes aegypti - Proteins ; Aedes aegypti - Public health

Data de publicação: 2007