Evolutionary studies in vertebrates: I. Cytogenetic, molecular and morphological analyses. II. Karyotypical survey of Brazilian fauna. III. Cell and tissue collection of mammals, lizards and amphibians

Abstract

This project will use a multidisciplinary approach to study the Brazilian vertebrate fauna, focusing on rodents, marsupials, lizards and amphibians. Cytogenetical, molecular and morphological tools will be used. Chromosomal characterization will be based on routine cytogenetic and banding techniques, fluorescent in situ hybridization (FISH) using telomeric and ribosomal probes, and chromosome painting after microdissection and PCR amplification procedures. All these techniques were previously been succesfully used by our lab, and in these studies many questions about chromosomal evolution in different vertebrate groups has been resolved. Morphological analyses in rodent species of genus Akodon have defined diagnostical characters which are essential to species identification. Data from chromosomal polymorphisms and frequencies of rearrangements in Akodon cursor have contributed to understand the dispersal and geographic distribution of this species. As for Oryzomyini rodents, karyotypical data have been considered an essential tool in distinguishing species and clarifying specifice problems involving the group. Mitochondrial DNA sequencing studies are also an important tool, and associated with cytogenetic and morphological data, can and will be used to establish phylogenetic relationships among taxa, in particular for rodents and lizards. Our group have been participating in a large number of multidisciplinary research projects on zoology and ecology. This has resulted in a remarkable collection of vertebrate specimens. The Laboratório de Citogenética de Vertebrados has in storage a comprehensive cell culture collection of mammals and lizards that guarantees a continuous source of fibroblast cells. Cryogenic preserved tissues from several species of mammals, lizards and amphibians are also available, permitting a broad diversity of cytogenetic, biochemical and DNA investigations. Our collection, due to the breadth of species and large number of samples, can be considered an exceptional source of material for biodiversity studies. (AU)