SD Locus (Shedding) in Dogs

Acronym:	SD Locus
Gene:	MC5R
Mutation:	c.709G>A
Inheritance:
Sample type:	CHS (Cheek Swab), WBE (Whole Blood EDTA)

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Genetics and characteristics

Some important coat characteristics in dogs include its length along with coat color, growth pattern, and curl. Another important characteristic is coat shedding, or losing hairs. Shedding occurs as old hairs enter the resting phase and essentially die, allowing new hair growth to occur. It has been discovered that shedding in dogs and other mammals is under the control of several genes, and one of the important ones is the melanocortin receptor 5 (MC5R) gene. The MC5R gene is expressed in the hair follicle glands that produce the oily, waxy substance called sebum. This secretion of sebaceous glands keeps the hair flexible and assists in lubrication, thermo-regulation, and water repellence. The variants that cause a conformational change in the tertiary structure of the protein MCR5 disrupt the structure of sebum and result in increased shedding in some dog breeds.

Shedding in dogs has a complex inheritance pattern, involving several genes, but variant in just the MCR5 gene has a somewhat dominant inheritance pattern. That means, dogs with no mutated copy of the MCR5 gene will have normal shedding. On the other hand, dogs carrying one copy of this variant will have increased shedding, and dogs inheriting two copies will have an even higher degree of shedding. 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:

Hayward, J. J., Castelhano, M. G., Oliveira, K. C., Corey, E., Balkman, C., Baxter, T. L., Casal, M. L., Center, S. A., Fang, M., Garrison, S. J., Kalla, S. E., Korniliev, P., Kotlikoff, M. I., Moise, N. S., Shannon, L. M., Simpson, K. W., Sutter, N. B., Todhunter, R. J., Boyko, A. R. (2016). Complex disease and phenotype mapping in the domestic dog. Nature communications, 7, 10460. https://doi.org/10.1038/ncomms10460