Study on the variability of venom in snakes of the Bothrops jararaca complex and its correlation with the processes of speciation in continental islands

Abstract

The molecular mechanisms of adaptive evolution are little known. So far, it is not known how the complex evolutionary novelties are generated during the recent processes of speciation. Distinct phenotypic characteristics could arise due to changes in gene regulation or directional selection of mutations in the genes themselves. Isolated venomous snakes on islands are powerful models for studies on the evolutionary processes that generate phenotypic diversity. The venoms produced by the species of Bothrops jararaca complex are considered highly related to the availability of prey of the same. Populations of B. jararaca underwent several processes of recent speciation, in the continental islands of southeastern Brazil, making these island populations an extreme case of recent adaptation to distinct niches. This project aims to evaluate the complexity of venoms in both island and continental populations of the Bothrops jararaca complex in order to infer the importance of venom composition in the adaptation of these populations to the niche in which they are found. For this, we will analyze the chromatographic profiles of the individual venoms, generate the transcriptome of the venom glands and characterize the proteome of each venom by mass spectrometry analysis. Based on the results obtained, we will try to correlate the venom diversity to the demographic, biological and ecological parameters of the populations sampled. In this way, we will test the hypothesis that the rapid phenotypic differentiation between closely related species can be shaped by an intense process of natural selection, which would support theories of ecological speciation through the rapid adaptation to different niches.