Issue |
Genet. Sel. Evol.
Volume 33, Number 5, September-October 2001
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Page(s) | 529 - 542 | |
DOI | https://doi.org/10.1051/gse:2001131 |
Genet. Sel. Evol. 33 (2001) 529-542
Differentiation among Spanish sheep breeds using microsatellites
Juan-José Arranz, Yolanda Bayón and Fermín San PrimitivoDepartamento de Producción Animal, Universidad de León, 24071 León, Spain
(Received 2 November 2000; accepted 23 April 2001)
Abstract
Genetic variability at 18 microsatellites was analysed on the basis of
individual genotypes in five Spanish breeds of sheep -Churra, Latxa,
Castellana, Rasa-Aragonesa and Merino -, with Awassi also being
studied as a reference breed. The degree of population subdivision
calculated between Spanish breeds from
diversity
indices was around 7% of total variability. A high degree of
reliability was obtained for individual-breed assignment from the 18
loci by using different approaches among which the Bayesian method
provided to be the most efficient, with an accuracy for nine
microsatellites of over 99% . Analysis of the Bayesian assignment
criterion illustrated the divergence between any one breed and the
others, which was highest for Awassi sheep, while no great differences
were evident among the Spanish breeds. Relationships between
individuals were analysed from the proportion of shared alleles. The
resulting dendrogram showed a remarkable breed structure, with the
highest level of clustering among members of the Spanish breeds in
Latxa and the lowest in Merino sheep, the latter breed exhibiting a
peculiar pattern of clustering, with animals grouped into several
closely set nodes. Analysis of individual genotypes provided valuable
information for understanding intra- and inter-population genetic
differences and allowed for a discussion with previously reported
results using populations as taxonomic units.
Key words: microsatellites / sheep breeds / population assignment / individual clustering analysis
Correspondence and reprints: Yolanda Bayón E-mail: dp1ybg@unileon.es
© INRA, EDP Sciences 2001