Journal of Heredity Advance Access published online on February 21, 2008
Journal of Heredity, doi:10.1093/jhered/esm115
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Genetic Analysis of White Facial and Leg Markings in the Swiss Franches-Montagnes Horse Breed
From the Swiss College of Agriculture, Länggasse 85, 3052 Zollikofen BE, Switzerland (Rieder and Hagger); the Institute of Genetics, Vetsuisse Faculty, University of Berne, Bremgartenstrasse 109a, 3012 Bern, Switzerland (Obexer-Ruff and Leeb); and the Swiss National Stud Farm, 1580 Avenches VD, Switzerland (Poncet)
Address correspondence to S. Rieder at the address above, or e-mail: stefan.rieder{at}shl.bfh.ch.
White markings and spotting patterns in animal species are thought to be a result of the domestication process. They often serve for the identification of individuals but sometimes are accompanied by complex pathological syndromes. In the Swiss Franches-Montagnes horse population, white markings increased vastly in size and occurrence during the past 30 years, although the breeding goal demands a horse with as little depigmented areas as possible. In order to improve selection and avoid more excessive depigmentation on the population level, we estimated population parameters and breeding values for white head and anterior and posterior leg markings. Heritabilities and genetic correlations for the traits were high (h2 > 0.5). A strong positive correlation was found between the chestnut allele at the melanocortin-1-receptor gene locus and the extent of white markings. Segregation analysis revealed that our data fit best to a model including a polygenic effect and a biallelic locus with a dominant-recessive mode of inheritance. The recessive allele was found to be the white trait-increasing allele. Multilocus linkage disequilibrium analysis allowed the mapping of the putative major locus to a chromosomal region on ECA3q harboring the KIT gene.
Corresponding Editor: Ernest Bailey
Received July 26, 2007
Accepted October 27, 2007