Lack of gene flow between peridomestic and sylvatic Triatoma infestans from Chaco, Argentina

PICCINALI ROMINA, CEBALLOS LEONARDO, KITRON URIEL AND GURTLER RICARDO

Barcelona, España

Congreso; 2008 Annual Meeting of the Society of Molecular Biology and Evolution; 2008

Society of Molecular Biology and Evolution

Triatoma infestans is the main vector of Trypanosoma cruzi, the etiological agent of Chagas’ disease in Argentina and other South American countries. Though T. infestans is a domestic or peridomestic species, recent findings suggest that sylvatic populations of T. infestans are more widespread than previously suspected. One important question is whether sylvatic foci could represent sources for reinfestation of peridomestic and domestic sites after insecticide spraying. In this work we sequenced a fragment of the mitochondrial gene COI in order to elucidate the degree of gene flow and phylogenetic relationships between peridomestic and sylvatic bugs from Chaco Province, Argentina. Sylvatic bugs showed a high haplotype diversity (h=7 hd=0.964 N=7) whereas all peridomestic bugs carried the same haplotype (h=1 hd=0 N=14). Non shared haplotypes were detected between sylvatic and peridomestic bugs. The most parsimonious tree of the haplotypes showed two clades separated by several mutational steps: one with two sylvatic haplotypes and the other with the remaining sylvatic and the domestic haplotype. These results suggest that a)there is not significant current gene flow between sylvatic and domestic bugs; b)sylvatic bugs from Chaco could belong to an ancient population of the species, and c)the domestic haplotype could have arisen from sylvatic variants.