Hybridization in Triatominae (Hemiptera, Reduviidae): would Haldane's rule be an applicable principle for Chagas disease vectors?

Abstract

Triatomines are hematophagous insects of great epidemiological importance, as they act as vectors for the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Currently, there are 154 species described in the subfamily Triatominae, grouped into 19 genera and five tribes. Several cases of natural and/or experimental hybridization were observed among the insect vectors of Chagas disease. Hybridization events are important sources of new variations, new adaptations and even new species, since viable and fertile hybrids can interbreed and / or backcross with one or both parental species, which allows for genetic introgression. Among the different factors that can influence the direction and intensity of introgression in hybrid zones, the action of Haldane's rule can be highlighted. This rule was described in 1922 and predicts that "when in hybrid offspring a sex is absent, it is rare or sterile, that sex is heterogametic", that is, the heterogametic sex (XY) is the first to be affected by the evolutionary events that they make it impossible or lead to the sterility of hybrids, which can lead to differential introgression of genes (autosomal and / or linked to sex). Thus, the present project aims to perform interspecific experimental crosses between different species of triatomines and to evaluate the proportion between males and females of the resulting hybrids, with emphasis on the Haldane rule.