OMIA 001638-9940 : Coat colour, piebald in Ovis aries

In other species: Arabian camel , golden hamster

Mendelian trait/disorder: no

Considered a defect: no

Key variant known: no

Inheritance: Despite the word "mutation" appearing in the title of his paper, Gregory (1950) provided no evidence for any form of inheritance (single-locus or otherwise) for the piebald phenotype exhibited by the single sheep he reported. Investigations of the inheritance of this phenotype (e.g. by Brooker and Dolling, 1969) ruled out any single-locus form of inheritance. Decades later, in a landmark paper combining the power of SNP-based genome-wide association analysis and network analysis of gene expression data, Garcia-Gámez et al. (2011) showed clearly the multifactorial nature of inheritance of this trait, and were able to identify several genes showing relevant differential expression that are located in the regions of highly-associated SNPs (see section on Molecular basis).

Molecular basis: Garcia-Gámez et al. (2011) identified thirteen genes at the intersection of two inferred networks (one regulatory and the other epistatic), "with insulin-like growth factor binding protein 7 (IGFBP7), platelet-derived growth factor alpha (PDGFRA) and the tetraspanin platelet activator CD9 at the kernel of the intersection". They also identified "differentially expressed genes in regions containing highly associated SNP including ATRN, DOCK7, FGFR1OP, GLI3, SILV and TBX15". Reverter and Fortes (2013) reviewed this work.

References


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.
2013 Reverter, A., Fortes, M.R. :
Breeding and Genetics Symposium: building single nucleotide polymorphism-derived gene regulatory networks: Towards functional genomewide association studies. J Anim Sci 91:530-6, 2013. Pubmed reference: 23097399. DOI: 10.2527/jas.2012-5780.
2011 García-Gámez, E., Reverter, A., Whan, V., McWilliam, S.M., Arranz, J.J., Kijas, J. :
Using regulatory and epistatic networks to extend the findings of a genome scan: identifying the gene drivers of pigmentation in merino sheep. PLoS One 6:e21158, 2011. Pubmed reference: 21701676. DOI: 10.1371/journal.pone.0021158.
1990 Denis, B., Malher, X. :
Description and Genetic Determination of Piebaldness of the Lateral Depigmentation Type in Vendee Sheep Breed Recueil de Medecine Veterinaire 166:777-781, 1990.
Fleet, M.R., Smith, D.H. :
Pigmented Fibres in White-Skirted Fleece Wool from Piebald Merino Sheep Australian Journal of Agricultural Research 41:155-166, 1990.
1987 Ryder, M.L., Adalsteinsson, S. :
A note on differences in coat structure between the black and white areas of piebald lambs Journal of Agricultural Science 108:379-382, 1987.
1969 Brooker, M.G., Dolling, C.H.S. :
Pigmentation of sheep. III. Piebald patterns in Merinos Australian Journal of Agricultural Research 20:523-532, 1969.
1950 Gregory, P.W. :
A piebald mutation in sheep. J Hered 41:39-40, 1950. Pubmed reference: 15415588.

Edit History


  • Created by Frank Nicholas on 17 Oct 2011
  • Changed by Frank Nicholas on 17 Oct 2011
  • Changed by Frank Nicholas on 20 Sep 2013