Dog Coat Color - I Locus (Intensity)

Acronym:	I locus
Gene:	MFSD12
Mutation:	c.151C>T
Inheritance:	Autosomal recessive
Sample type:	CHS (Cheek Swab), WBE (Whole Blood EDTA)

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Genetics and characteristics

Coat color in dogs is an important characteristic along with hair length, growth pattern, and curl and it is determined by the expression of two melanin pigments, eumelanin (black/brown) and pheomelanin (yellow/red). White coat color is a common color in dogs caused by at least two underlying distinct genetic mechanisms: the absence of melanocytes or the absence of pigment in the melanocytes. One of those mechanisms involves a variant within the MFSD12 gene also known as I (Intesity) Locus that controls the intensity of the red pigment (phaeomelanin). If red dogs that have a mutation causing the absence of eumelanin also carry an MFSD12 mutation, their coat color will be diluted to an extremely pale cream or a white color. However, such dogs are not albino and retain pigmentation in their nose, leather, eye rims, lips, or pads.

Dilution of coat color caused by an MFSD12 variant has a complex inheritance pattern, involving several other genes. MFSD12 mutation shows an autosomal recessive mode of inheritance meaning both mutated genes are required for the red and yellow pigment dilution to cream or white color. In dogs, the MFSD12 In variant has only been shown to decrease red/yellow pigment leaving black/brown pigment unaffected. That means if the dog has a brown or black coat, MFSD12 mutation will not affect its coat color. Genetic testing can identify carriers and help breeders in future mating pairs selection.

 

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Results Reported As

 

 

 

 

 

 

 

 

 

 

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References:

Hédan, B., Cadieu, E., Botherel, N., Dufaure de Citres, C., Letko, A., Rimbault, M., Drögemüller, C., Jagannathan, V., Derrien, T., Schmutz, S., Leeb, T., & André, C. (2019). Identification of a Missense Variant in MFSD12 Involved in Dilution of Phaeomelanin Leading to White or Cream Coat Color in Dogs. Genes, 10(5), 386. https://doi.org/10.3390/genes10050386

Slavney, A. J., Kawakami, T., Jensen, M. K., Nelson, T. C., Sams, A. J., & Boyko, A. R. (2021). Five genetic variants explain over 70% of hair coat pheomelanin intensity variation in purebred and mixed breed domestic dogs. PloS one, 16(5), e0250579. https://doi.org/10.1371/journal.pone.0250579