Genetic characterization of the autochthonous sheep populations from Chiapas, Mexico

The Tzotziles, a Mayan native group located in Chiapas, Southern Mexico, have sheep breeding as one of their principal means of subsistence. Sheep were introduced in the Americas by the Spaniards in the first half of the XVI Century. Three populations of sheep from Chiapas-Cafe, Chamula and Chiapas-were typed with 27 microsatellites. Genetic distances were calculated for three Iberian breeds, Spanish Merino, Churra, two Canary Islands breeds, Canaria and Palmera, and the French Mutton Merino (Precoce). In the case of Chiapas sheep most of the markers showed Hardy-Weinberg equilibrium and the fixation index of Fst (0.095) showed a moderate level of genetic differentiation. The three distinct sheep subpopulations (Cafe, Chamula. and Chiapas) are genetically differentiated inside the Chiapas sheep population. These breeds could be historically related to Spanish sheep populations, but have diverged significantly as a result of genetic drift and selection. (c) 2007 Elsevier B.V. All rights reserved.