Prospection of genetic markers for the evolutionary study of anurans of the genus Physalaemus

Abstract

The recent finding of high cytogenetic and genetic diversity among populations related phylogenetically to the taxaPhysalaemus cuvieri and Physalaemus ephippifer raises new questions about the evolution of these anurans. The presence of sex chromosome heteromorphism in the lineage of P. ephippifer, which is absent in the other lineages yet studied, makes the investigation of species delimitation especially intriguing in this group. In this context, and taking into account the high potential of genomic technologies for phylogeography, the present proposal arises as a great opportunity to develop powerful new markers for further evolutionary studies of the P. cuvieri-P. ephippifer complex. In addition, new effort will be done to increase the sample of individuals in study, especially to include individuals from São Pedro da Água Branca-MA, which was already studied cytogenetically and showed some typical traits with regards to NOR distribution. Sequences from the mitochondrial genes 12S, 16S and tRNA-val will be obtained from the new sampled individuals and they will be included in the phylogenetic inferences and distance analysis conducted previously. For the development of new genetic markers, we will use ddRAD-seq (double-digestion Restriction-site Associated DNA sequencing). Libraries enriched for restriction-fragments will be constructed from the genomic DNA obtained from individuals that belong to the major clades recognized by previous phylogenetic inferences. In this study, we will have the collaboration of Dr. Benjamin Fitzpatrick, an investigator with great expertise in the analysis of hybridization and speciation processes using particularly genomic approach.