OMIA 001079-9940 : Yellow fat in Ovis aries

In other species: horse , pig , cattle , rabbit

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal Recessive

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2010

Species-specific description: The presence of three xanthophylls (lutein, lutein-5-6-epoxide, and flavoxanthin) in sheep fat, presumably due to the inability to oxidise xanthophylls. Inherited as a single-locus autosomal recessive trait.

The paper by Niu et al. (2017) reports a genetically-modified organism (GMO)

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
BCO2 beta-carotene oxygenase 2 Ovis aries 15 NC_040266.1 (25021687..25091194) BCO2 Homologene, Ensembl, NCBI gene


By default, variants are sorted chronologically by year of publication, to provide a historical perspective. Readers can re-sort on any column by clicking on the column header. Click it again to sort in a descending order. To create a multiple-field sort, hold down Shift while clicking on the second, third etc relevant column headers.

WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Breed(s) Variant Phenotype Gene Allele Type of Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
Norwegian White Yellow fat BCO2 nonsense (stop-gain) Oar_v3.1 15 g.21947481C>T c.196C>T p.Q66* 2010 20122251 Variant coordinates obtained from or confirmed by EBI's Some Effect Predictor (VEP) tool


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.
2017 Niu, Y., Jin, M., Li, Y., Li, P., Zhou, J., Wang, X., Petersen, B., Huang, X., Kou, Q., Chen, Y. :
Biallelic β-carotene oxygenase 2 knockout results in yellow fat in sheep via CRISPR/Cas9. Anim Genet 48:242-244, 2017. Pubmed reference: 27862083. DOI: 10.1111/age.12515.
2010 Vage, DI., Boman, IA. :
A nonsense mutation in the beta-carotene oxygenase 2 (BCO2) gene is tightly associated with accumulation of carotenoids in adipose tissue in sheep (Ovis aries). BMC Genet 11:10, 2010. Pubmed reference: 20122251. DOI: 10.1186/1471-2156-11-10.
1985 Baker, R.L., Steine, T., Vabeno, A.W., Breines, D. :
The inheritance and incidence of yellow fat in Norwegian sheep Acta Agriculturae Scandinavica 35:389-397, 1985.
1972 Gedde-Dahl, T.W. :
[Reduction of the yellow fat incidence by different breeding plans for sheep]. Nord Vet Med 24:620-30, 1972. Pubmed reference: 4666502.
1962 Hill, F. :
Xanthophyll pigmentation in sheep fat. Nature 194:865-6, 1962. Pubmed reference: 13907341.
1934 Castle, W.E. :
Yellow fat in sheep Journal of Heredity 25:246-247, 1934.

Edit History

  • Created by Frank Nicholas on 13 Oct 2010
  • Changed by Frank Nicholas on 14 Sep 2011
  • Changed by Frank Nicholas on 09 Dec 2011
  • Changed by Frank Nicholas on 24 Nov 2016
  • Changed by Frank Nicholas on 12 May 2017