Genetic diversity of Brazilian pig breeds evidenced by microsatellite markers

The genetic diversity within and between five genetic groups of pigs in Brazil. (n = 182) represented by three naturalized breeds (Moura, Piau and Monteiro), one commercial breed (Landrace) and one commercial composite (MS60) was estimated using 28 microsatellite markers. The genetic structure within these groups was also tested. The results showed that 14% of the total variation (p < 0.001) observed was due to differences between breeds. Based on the UPGMA dendrogram obtained from Nei's D-A genetic distance it was possible to differentiate three groups. The first was formed by the commercial breed, Landrace, and the composite MS60, the second by two of the naturalized breeds (Piau and Monteiro) and the third by the Moura naturalized breed. Within breed variability indicated that the Piau breed had the highest value of expected heterozygosity among the naturalized breeds, whereas Landrace had the highest value between the commercial breeds. Using a Bayesian analysis, a population substructure was identified in Monteirc, and Piau breeds. Furthermore, lower values for breed certification probability were observed for these two breeds as well as a significant genetic differentiation between the Moura and Landrace breeds and the composite MS60. The microsatellite marker panel possessed high precision (99.99%) when used in paternity exclusion in naturalized pig breeds and proved to be an effective tool for the management and conservation of naturalized pig breeds. (C) 2008 Elsevier B.V. All rights reserved.