Preliminary analysis of genetic structure of synanthropic populations of Rhodnius ecuadoriensis from coastal Ecuador

Chagas disease (CD) is a parasitic infection caused by the flagellate protozoan Trypanosoma cruzi. The disease is distributed from southern United States to Argentina. Rhodnius ecuadoriensis, the most important CD vector in Ecuador, occurs in both artificial and sylvatic habitats. This study was conducted in 8 communities in the province of Manabí, aiming to assess the applicability of microsatellites designed for Rhodnius pallescens to determine whether there is genetic differentiation among synanthropic and wild populations of R. ecuadoriensis. We evaluated six microsatellites, but only two markers were polymorphic in R. ecuadoriensis, two were difficult to read and the other two were monomorphic markers. Polymorphic microsatellites L13 and L47 showed no significant differences between synanthropic and sylvatic populations or among localities (FST = 0.08; p = 0.05). This suggests high rates of gene flow among R. ecuadoriensis populations in Manabí, which probably represent a single metapopulation. This lack of population genetic structuring is consistent with morphological analyses of R. ecuadoriensis specimens from Manabí and data from R. prolixus in Venezuela. The results presented here open the way for the development of specific microsatellites for R. ecuadoriensis, and therefore for the detailed study of the population dynamics of this local CD vector.