Desenvolvimento de microssatelites e analise populacional de especies de Physalaemus do grupo "cuvieri" (Anura, Leiperidae) / Microsatellites development and populational analysis of Physalaemus species of the "cuvieri" group (Anura, Leiperidae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Even though many amphibian species are among the most endangered animals, the knowledge about their genetic variability and population genetic structure is still limited. In the present work, natural populations of the barker frog Physalaemus cuvieri were analyzed for genetic variability and differentiation using microsatellites, considering its wide geographic distribution, interpopulational morphological variation and cytogenetic intra- and interpopulational variation. Analyzes comprised specimens from ten P. cuvieri populations sampled in the following regions of Brazil: São Pedro da Água Branca (MA), Urbano Santo (MA), Porto Nacional (TO), Uberlândia (MG), Vitória Brasil (SP), Palestina (SP), Nova Itapirema (SP), Chapada dos Guimarães (MT), Vitória da Conquista (BA) and Passo Fundo (RS). Ten microsatellite loci were isolated for P. cuvieri from a library enriched in (CA)8 and (GT)8 repeats. In 160 P. cuvieri individuals, the average number of alleles per locus was 5.7 and the expected heterozygosity ranged from 0.30 to 0.85. Although most of the genetic variation was found within populations, the overall FST value indicated high genetic differentiation among the populations. The low gene flow among populations suggested low dispersion capability within the geographic scale pattern used in this work, which is compatible with the anuran philopatric behavior. In addition, there was no correlation between geographic and genetic distances of these populations, suggesting fidelity of P. cuvieri populations to their spawning place. These results indicated that the geographic distance alone does not explain the genetic variability observed among these populations. The data also indicated that the populations from São Pedro da Água Branca (MA) and Nova Itapirema (SP), respectively in the Northeast and Southeast regions of Brazil, have likely gone through a recent population bottleneck effect. Destruction of natural habitats leading to population fragmentation could be a major cause of this suggested bottleneck effect. Of the ten microsatellite loci developed for P. cuvieri, nine were used to investigate cross-amplification and suitability for population genetic structure studies in two other species of the cuvieri group closely related to P. cuvieri. These species are: P. ephippifer (15 specimens) and P. albonotatus (11 specimens). These two populations remained isolated from all populations of P. cuvieri, demonstrating its high genetic differentiation, pointing that these two species are distinct from P. cuvieri. The Crateús (CE) population was grouped with Urbano Santos (MA) population (both P. cuvieri). This result corroborated previous cytogenetic results. The Porto Nacional (TO) and Passo Fundo (RS) populations were divided in two sets of individuals each one. Part of Porto Nacional individuals were clustering with P. cuvieri from Uberlândia (MG), and the remaining did not show any grouping with none of other analyzed species. Similar results were found to Passo Fundo population, which also did not show any group with the analyzed species. The knowledge of the dispersion pattern of the P. cuvieri genetic variability evaluated by microsatellites, in addition to the genetic variability data obtained using other methodologies, will contribute for the development of future ecological and conservation strategies and to improve the taxonomy of this species.

ASSUNTO(S)

microssatelites (genetic) genetica de populações populations genetics anuro - população anura microssatelites (genetica) physalaemus physalaemus

ACESSO AO ARTIGO

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