October 23, 2018

Coat Color in Pointer Dogs

Examination of Stud Book From Mendelian Viewpoint Suggests That Relation of Brown to Black is the Same in Dogs as in Other Small Mammals Which Have Been Investigated, and That There are Two Types of Yellow—Practical Breeding Rules.

In 1914 at the Bussey Institution, C.C. Little endeavored to uncover the genetics of coat color in pointer dogs. At this time Mendel’s research had recently been rediscovered researchers aimed to investigate inheritance in many species as it could help with breeding. C.C. Little believed that Mendel’s law could help explain the four distinct colors of pointer dogs: black, liver (brown), yellow with a black nose, and yellow with a pinkish-brown nose (Little 244).

 

In order to find relationships in inheritance he used AKC stud books and examined the outcomes of 186 AKC standard pointer dog breedings (Little 244). He aggregated the different coat color combinations in a table (see original article) and concluded that there are two alleles for coat color. He defined them as the following:

 

"B: The factor for black pigment which is absent from brown (liver) animals.

E: The factor for extension of the brown and black pigment in the hair. In the presence of this factor, animals have spots of brown or black pigment on a white ground; in its absence the colored spots on the coat are yellow of various shades." (Little 246)

 

From this, we can determine the genotypes of pointer dogs and their respective coat color phenotype. Since the E allele codes for color in the hair and B codes for black vs liver we can determine that BE genotype would result in a black coated pointer dog while bE would result in the liver coat phenotype. The yellow dogs are less straightforward, but looking at the color of the nose helps us conclude that a Be pointer would show a yellow coat with a black nose and a be genotype would result in a yellow coat with a pinkish-brown nose. Little concludes his research with the breeding applications of his research and describes how breeders could select for certain coat colors.

 

Reference: https://academic.oup.com/jhered/article-pdf/5/6/244/2763771/5-6-244.pdf

 

C.C. LITTLE; COAT COLOR IN POINTER DOGS: Examination of Stud Book From Mendelian Viewpoint Suggests That Relation of Brown to Black is the Same in Dogs as in Other Small Mammals Which Have Been Investigated, and That There are Two Types of Yellow—Practical Breeding Rules., Journal of Heredity, Volume 5, Issue 6, 1 June 1914, Pages 244–248, https://doi.org/10.1093/oxfordjournals.jhered.a107862

 

Reviewed by Ian J. Sessions | 25 October 2018