Analysis of the genetic structure of interspecific crosses using species of the genus Mepraia (Hemiptera, Reduviidae, Triatominae).

Abstract

Triatomines are vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease, which has a wide distribution in the Neotropical region. In Chile, there are four species of vectors for this zoonosis, namely Mepraia gajardoi, M. spinolai, M. parapatrica and Triatoma infestans. In addition to the vectorial importance in the transmission of Chagas disease, triatomines are biological models for cellular studies and contribute to the knowledge of the physiology and evolution of insects. In view of the evolutionary aspects, interspecific crosses of triatomines have been quite intriguing when considering the biological concept of species, since natural and / or artificial hybridization occurs with some frequency in the subfamily Triatominae. Thus, promoting hybridization, with crossings up to at least the third generation (F3) so that post-zygotic reproductive isolation barriers can be characterized can bring valuable information about this process. Based on recent questions about the specific status of M. parapatrica (present in the distribution limits of the other Mepraia species, which led to the suggestion that it is a hybrid between the species M. spinolai and M. gajardoi) and, mainly, in the importance of cytogenetics and experimental crossings for the taxonomy of Triatominae, the present project aims to perform a multidisciplinary and integrated analysis of evolutionary (pre and post-zygotic barriers) and taxonomic aspects in Mepraia spp., by means of analyzes in Mepraia spp., as well as experimental crosses between M. parapatrica x M. spinolai and M. parapatrica x M. gajardoi and analysis of the resulting hybrids up to third generation (F3), with emphasis on the analysis of the evolutionary dynamics of experimental crosses (copulation) , oviposition, hatching and hybrid development), as well as in the analysis of reproductive viability (spermatogenesis and morphology of g male and female onadas), segregation of phenotypic and genotypic characteristics of parents in experimental hybrids. In addition, it is intended to deposit the hybrids in entomological collections, in order to avoid the description of new species from possible natural hybrids. These results will allow to elucidate evolutionary and taxonomic issues related to M. parapatrica.