Estudo genético de populações caprinas locais e exóticas através de marcadores microssatélites

Abstract

The aim of the present study was develop a panel of microsatellites for testing paternity in goats as an aid for conservation and improvement programs for local breeds. A total of 381 animals from 10 goat populations [six local Brazilian ecotypes/breeds (Azul, Canindé, Graúna, Marota, Moxotó and Repartida) and four exotic breeds currently used in Brazil (Alpine, Anglo-Nubian, Boer and Saanen) were genotyped. Nine multiplex systems were performed, totaling 27 microsatellites.Polymorphism information content (PIC), probability of exclusion (PE) of the markers and Hardy- Weinberg (HW) equilibrium were estimated for the populations and the probability of identity was determined. For the system with 27 microsatellites, the combined PE was 0.999991 and 0.999999 (PE1 and PE2) and the 21 microsatellites exhibited PIC > 0.60; four microsatellites were monomorphic in some populations. Significant deviations from HW equilibrium (P< 0.05) were found for the markers; CSSM66 was deviated from HW equilibrium in the greatest number of populations (8). Nine markers were selected to make up the panel, eight of which were common to both groups (local and exotic goats); the BM1818 marker was the most informative in the local populations and the BM6506 marker was the most informative in the exotic populations. Combined PE with the group of eight microsatellites was 0.9943 and 0.9997 (PE1 and PE2). Based on the calculation of the probabilities of exclusion within the populations, it was possible to discriminate one individual from among a million (106). The results indicate the possibility of employing few microsatellites in the investigation of paternity in goats with a satisfactory degree of reliability and minimal cost.