Reduced hair shedding (MC5R) is a complex genetic trait that can affect all breeds and has epistatic interactions with FGF5 (coat length) and RSPO2 (furnishing), which also affect hair morphology in dogs. These loci have undergone selective sweeps due to a strong artificial selection for fur phenotype. The MC5R protein sequence is evolutionarily conserved across mammals, and a certain mutation causes a conformational change in the tertiary structure of the protein that is involved in the production of sebum, affecting water repellency and thermo-regulation, which can result in increased shedding. The genetic test can reveal the degree of shedding in a dog which can help to select dogs suitable for breeding and reduce shedding. Because individual genes only give average values for shedding it is almost necessary to test the combination of MC5R and RSPO2 genes.
Bellow are 3 tables that are showing the degree of hair shedding depending on genotype; the last one illustrates the degree of hair shedding depending on genotype combination of MC5R and RSPO2.
MC5R
|
Genotype
|
Degree of shedding
|
|
SD/SD
|
Low
|
|
SD/N
|
Moderate
|
|
N/N
|
High
|
N – wild type allele, SD - variant allele
Dogs with one or two copies of the variant alleles shed less than dogs with no copies.
RSPO2
|
Genotype
|
Degree of shedding
|
|
F/F
|
Low
|
|
F/N
|
Moderate
|
|
N/N
|
High
|
F/F - furnishing, N/F- furnishing, N/N - improper coat
MC5R and RSPO2 COMBINATION
|
Genotype MC5R
|
Genotype RSPO2
|
Degree of shedding
|
|
SD/SD
|
F/F
|
0
|
|
SD/SD
|
F/N
|
1
|
|
SD/SD
|
N/N
|
2
|
|
SD/N
|
F/F
|
1
|
|
SD/N
|
F/N
|
2
|
|
SD/N
|
N/N
|
3
|
|
N/N
|
F/F
|
2
|
|
N/N
|
F/N
|
3
|
|
N/N
|
N/N
|
4
|
Degrees of shedding: low 0 < 1 < 2 < 3 < 4 high
