Sunshine (Dilution factor Horse)
The Sunshine mutation lightens the coat, mane and tail colour of the horse. It is visually very similar to the Pearl dilution and is located on the same gene as the Cream dilution factor. It was found in a horse of the cross breed Standardbred x Tennessee Walking Horse.
General Information
- Sunshine is a dilution factor.
- Dilution affects coat as well as mane and tail.
- Phenotype is very similar to the Pearl dilution.
- Causal mutation affects the same gene as the Cream mutation.
- Recently found in a Standardbred x Tennessee Walking Horse cross.
Test Information
Locus Information: C-Locus
This test detects a single base pair change (ECA21:SLC45A2:c.568G>A) in the SLC45A2 gene.
Genotype and Lab Report
Inheritance: autosomal recessive
→ Only animals with two copies of the Pearl factor (sun/sun) or animals with one copy “Sunshine” in combination with one copy “Cream” (Cr/sun) show the Sunshine dilution.
Genotype
N/N = No Sunshine mutation
The horse does not show the diluted coat colour.
N/sun = One copy of the Sunshine variant, carrier
The horse does not show the diluted coat colour.
sun/sun = Two copies of the Sunshine variant
The horse does show the Sunshine dilution. Phenotype depends on base colour. The colour is visually very similar to Champagne dilution.
sun/Cr = One copy of the Sunshine variant with one copy of the Cream variant
The horse shows a phenotype similar to a horse with two copies of Cream (Cr/Cr).
Literature
Holl, H.M., Pflug, K.M., Yates, K.M., Hoefs-Martin, K., Shepard, C., Cook, D.G., Lafayette, C., Brooks, S.A., Holl, H.M., Pflug, K.M., Yates, K.M., Hoefs-Martin, K., Shepard, C., Cook, D.G., Lafayette, C., Brooks, S.A., Holl, H.M., Pflug, K.M., Yates, K.M., Hoefs-Martin, K., Shepard, C., Cook, D.G., Lafayette, C., Brooks, S.A.: A candidate gene approach identifies variants in SLC45A2 that explain dilute phenotypes, pearl and sunshine, in compound heterozygote horses. Anim Genet 50:271-274, 2019. Pubmed reference: 31006892. DOI: 10.1111/age.12790.
Further information is available at Online Mendelian Inheritance in Animals.