Estudo da variabilidade genética de Phyllamedusa bicolor (Anura; Hylidae) na Amazônia brasileira

Abstract

The species Phyllomedusa bicolor has biotechnological potential, since its secretion is rich in epidermal bioactive substance. This species, popularly known as the Indians Kambô cloth linguistic group, is used in healing rituais in preparation for hunting. It is a widely distributed species in the Amazon that lacks studies that focus on their evolutionary history and population structure. This study employed the use of mtDNA as a molecular tool to study 117 individuais of P. bicolor from eleven different locations in five states in the Brazilian Amazon. The database for the analysis population was composed of 117 nucleotide sequences, each with a total of 1037 base pairs (bp) which resulted in a database for the concatenated mtDNA (a fragment of 520 bp of 16S and a Control Region fragment of 517 bp). The sequences were aligned and edited in the BioEdit programo From these, we generated a data matrix that was used in the analysis population statistics implemented in the program ARLEQUIN. Analyses of Samovar and BAPS were used to determine the groupings of the populations later. Haplotype network, the data generated by the program GEODIS and interpretation of key Templeton were generated using the program ANECA. Verified the existence of 31 haplotypes for the mtDNA, and 21 are unique within the sample. The gene diversity (h) total was estimated at 0.884, and this value is high compared to the values of sites. The AMOVA test revealed that there is a strong genetic structure, which is significantly supported by the fixation index (<1>ST= 0.8166, P <0.001), where the bulk of ali genetic variation (81.66%) is distributed among the populations. Pairwise comparisons of gene flow show that populations of RF Adolpho Ducke, UFAM Rebio Uatumã and showed high values in the effective number of female migrants per generation (Nemf), which indicates that there is gene flow. The NCPA analysis defined six hierarchicallevels corresponding to c1ades, 1-7, 2-2, 2-7, 3-1, 3-2 and 4-1, where there is a rejection of the null hypothesis of no association between geographic distance and genetic divergence, most often indicating restricted gene flow. The value of K greater significance (K = 4) explains the formation of groups with the following configuration: group 1) UFAM, Adolfo Ducke Forest Reserve and Rebio Uatumã, group 2) Barcelos, PARNA Viruá and TNF Amapá, group 3 ) Altamira, group 4) Cruzeiro do Sul, Santa Isabel do Rio Negro, Tabatinga and Atalaia do Norte. On Bayesian analysis of population structure found that the best value of posterior probability for the formation of groups is a number equal to five. Four localities with high levels of genetic variability for mtDNA: RF Adolpho Ducke, Rebio Uatumã, UFAM and Acre. The segments of the 16S and Control Region (central part) were slightly conserved, which affect the number of segregating sites and reduced numbers of haplotypes found in populations of P. bicolor. By means of genetic distances, we find that there is a greater differentiation between pairs of localities in the Central Amazon, the Guyana Shield and the Brazilian Shield in relation to the western Amazonian localities. Therefore, our results indicate that possibly the populations of P. bicolor show a pattern of differentiation mediated by isolation by distance in view of the large geographic distances between locations found. However, additional sampling should be undertaken to provide more precise information on this pattern of differentiation.