Resumen de Genetic population structure of brazilian bovine breeds inferred by rapd markers

G. M. Serrano, A. A. Egito, C. McManus, A. S. Mariante

• Conservation and improvement strategies should be based on the association between genetic and phenotypic characteristics. In this study 10 different populations of five native Brazilian cattle breeds (Caracu, Mocho Nacional, Crioulo Lageano, Curraleira and Pantaneira) were characterized using RAPD techniques to estimate their genetic relationships and verify the existence of possible regional differences within each breed. Two commercial breeds were used as control and outgroup respectively (Holstein and Nellore). 120 arbitrarily primers were screened, of which 22 were selected, and generated 122 polymorphic bands. When all groups were analysed in pairs, non-significant genetic variability (p>0.05) observed only between two populations of Curraleiro breed located in States of Piaui (CUPI) and Minas Gerais (CUMG). Using Popgene program Nei"s 1978 genetic distance was estimated. The smallest divergences were observed between groups of the same breed and the least distance between the two groups of Caracu breed (0.0159). In the four populations of Curraleiro the groups CUPI and CUMG presented the smallest difference (0.0285). These results could indicate that these two populations have high genetic similarity. In the dendrogram generated by UPGMA method all groups clustered in their respective breed. In this study we could demonstrate the existence of regional genetic differences between the populations of native breeds. These estimates could be useful in crossbreeding and genetic sample exchange between different nuclei.