Morphologic and molecular characterization of hybrids from the cross breeding among Triatoma maculata (Erichson, 1848) and Triatoma pseudomaculata Corrêa amp; Espínola, 1964 (Hemiptera: Reduviidae)
Due to its great morphological similarities, Triatoma maculata and Triatoma pseudomaculata, classified by Carcavallo et al. (2002) in the ?maculata complex?, were considered the same species until 1964 (Corrêa e Espínola, 1964). These species are alopatric and, according to Schofield (1988), T. maculata would be introduced in the brazilian Northeastern by migratory birds, with subsequent speciation, forming the species T. pseudomaculata. Studies using isoenzymes showed great genetic distance among these two species and high affinity among T.pseudomaculata and Triatoma wygodzinsky, resulting in a new proposal of ´maculata complex` re-organization (Santos et al, 2003). Hybridization studies in Triatomines allow the formulation of hypothesis about the origin and divergence of species and may help to understand the systematic of the group. Therefore, the objective of this work was to determine the level of reproductive isolation among T. maculata and T. pseudomaculata, and to characterize genetically the species and hybrids obtained by the interspecific cross breeding, allowing the comparison of genetic aspects with other biological characteristics and behavior of these insects. T. maculata and T. pseudomaculata did not present difference in relation to the reproduction (eggs laid, time for eclosion and viability of the eggs) and are able to produce hybrids, but infertiles. The results obtained with the intra and interspecific cross breeding, morphological analysis, geometric morphometry and RAPDs showed T. maculata and T. pseudomaculata as well differentiated species. The hybrids obtained are morphologically more similar to T. maculata, but are genetically more close to T. pseudomaculata. T.wygodzinsky and the hybrids obtained with these species were the most distant from the other studied groups. Our results indicate that, independent of the existence or not of a common evolutive origin among these species at present they are already genetically well differentiated and would not constitute a complex.
Advisor:Liléia Diotaiuti; Álvaro José Romanha
School:Faculdades Oswaldo Cruz
Source Type:Master's Thesis
Keywords:triatoma maculata Triatoma pseudomaculata Morphologic and molecular characterization
Date of Publication:07/25/2006