Análise da variabilidade genética em populações de Anopheles darlingi Root, 1926 (Diptera: Culicidae) do Estado do Amazonas, usando marcadores RAPD

Abstract

Anopheles darlingi populations from Manaus, Coari, São Gabriel da Cachoeira and Tabatinga were analyzed by using the RAPD molecular marker, for the purpose of assessing the genetic variability and differentiation between them. Populations captured indoor and outdoor (around the house, corral) were also analyzed in Coari and Manaus, between 17:00h and 05:00h, in January and February of 2006. Genetic variability findings were high for mosquito’s four populations, showing it to be higher in São Gabriel da Cachoeira (P= 97.37%; He= 0.3202), and lower in Manaus (P= 78.94%; He= 0.2741). The chi-square test was significant (c2= 1589.5700; GL= 304; P < 0.001). The genetic structure analysis showed significant FST value (FST= 0,0851 ± 0,0075), indicating a reduced gene flow between populations. The “bootstrapping” consistency index for 1000 replicates was 95%. The genetic distance between populations was low (D= 0.0095 – 0.0502), showing to be lower between Coari and Tabatinga, and higher between São Gabriel da Cachoeira e Tabatinga. Despite the latter presenting higher genetic and geographic distance, data showed no clear relation with the Isolation by Distance Model (IBD), since Coari and Tabatinga revealed higher genetic similarity; however the lower geographic distance was between Manaus and Coari. Genetic variability analysis based on mosquito biting activity patterns, showed mosquitoes captured indoors presented highest genetic variability, where the polymorphism and expected heterozygosity were higher in both populations (Coari: P= 84.86% e He= 0.3069; Manaus: P= 78.94% e He= 0.2741). The chi-square test for the parameters was significant (c2= 695.8958; GL= 304; P < 0.001). Genetic structure analysis also showed a significant FST value (FST= 0.0775 ± 0.0072). The genetic distance between populations was low. For Manaus, the genetic distance between indoor and outdoor sub-populations was 0.0004, there being certain homogeneity among them. For Coari, the genetic distances were slightly higher, the highest being that between the outdoor (cattle) and the indoor (D= 0.0296), and the lowest between the indoor and the outdoor (D= 0.0081). As a whole, the data showed high genetic similarity between the analyzed populations, despite the little genetic structuring found. The highest genetic variability found the indoor, in the Coari and Manaus populations, indicates a higher genetic plasticity, and so it might confer them highest adaptability to the changes occurring in the environment.