Genetic variation at microsatellite loci in Spanish sheep

Genetic variation at 18 microsatellite loci was analysed in six indigenous Spanish sheep: Churra; Latxa; Manchega; Rasa-Aragonesa; Castellana and Meri no. Merinos had frequently the highest number of alleles per locus, whereas Latxas showed the lowest one at many loci. Markers ordered decreasingly ac cording to the number of variants differentiated in the whole population we re: MAF70; TGLA13; CSSM66; BM143, BM6444; MAF36; MAF64; CSSM6; TGLA53; OarF CB11; MAF33; BM4621; MAF48; MAF65; BM1258; ILSTS002; ADCYC and OarCP34. Par ameters of variability such as effective number of alleles and gene diversi ties corroborated the high level of variation frequently displayed by micro satellite markers. Comparison of allele distributions among populations and loci did not reveal consistent shapes. Distributions were centralised in s ome cases, whereas in others some kind of skewness was evident. Breed-speci fic alleles were detected at most loci, bring frequent in Merinos and rare in Churras. (C) 2001 Elsevier Science B.V. All rights reserved.