Traits and inheritance
Learn about modes of inheritance and basics of your dog genetics! you can find explanations of autosomal recessive and autosomal dominant inheritance. Some Examples of Dominant and Recessive Traits in Selected Domestic Animals . From: Genetics of Domestic Animals - Charles E. Stufflebeam. Species, Dominant Trait, Recessive Trait Dogs, Wire Hair, Smooth Hair. Black Hair, Liver Color. The field of genetics has progressed rapidly in recent years. Perhaps you've seen headlines about these top genetic topics in
Most black dogs are black due to a K locus allele. B brown locus[ edit ] The alleles at the B locus are related to the production of tyrosinase related protein 1 TYRP1 and determine the degree to which an animal expresses tyrosinasean enzyme related to the production of melaninin its coat and skin including the nose and paw pads. There are four known alleles that occur at the B locus: An animal that has at least one copy of the B allele will have a black nose, paw pads and eye rims and usually dark brown eyes.
An animal with any matched or unmatched pair of the b alleles will have brown, rather than black, hair, a liver nose, paw pads and eye rims, and hazel eyes. Phaeomelanin is slightly reduced from redder to oranger tan.
Only one of the alleles is present in the English Setter bsDoberman Pinscher bd and Italian Greyhound bcbut in most breeds with any brown allele 2 or all 3 are present. D dilute locus[ edit ] The alleles at the D locus the melanophilin gene or MLPH are related to the dilution of eumelanin and phaeomelanin and determine the intensity of pigmentation.
There are two known alleles: Homozygosity of d is sometimes accompanied by hair loss and recurrent skin inflammation, a condition referred to as either color dilution alopecia CDA or black hair follicular dysplasia BHFD depending upon the breed of dog. There are three known, plus two more theorized, alleles that occur at the E locus: The mask can vary from the muzzle, to the face and ears, to a larger area with shading on the front and sides as in the Belgian Tervuren.
Some puppies are born with a mask which fades away within a few weeks of birth: An animal that is homozygous for e will express a red to yellow coat regardless of most alleles at other loci.
Eumelanin is inhibited, so there can be no black hairs anywhere, even the whiskers.
Dog coat genetics
Pigment on the nose leather can be lost at the middle Dudley nose. Its placement in the dominance hierarchy has not been solidified. Its expression is dependent upon the animal not possessing Em nor E nor being homozygous for e. All cocker spaniels are homozygous for at, so it is unknown how the gene may function in the presence of other A-series alleles. H harlequin locus[ edit ] DNA studies have not yet isolated the gene at the H locus, but the traits associated with it have been mapped to chromosome 9.
There are two alleles that occur at the H locus: M merle locus[ edit ] See also: My generalization applies, within limits, to both structural and other inherited shortcomings and imperfections. That, however, is not the same thing as saying that recessive characteristics can never be considered as being as desirable.
The Fallacy Illustrated For example, your breed Standard calls for a dark eye.
You want to breed a litter and you, of course, want all of the puppies to have dark eyes. Your bitch has dark eyes. You have selected a top quality stud dog that is highly favored because he possesses a nice dark eye.
Since both sire and dam have dark eyes, the genes required for dark eyes are present. No worries, all of your pups will have dark eyes, right? Not necessarily, one or both of the parents must be homozygous dominant for dark eyes. To further illustrate my point, let me alter the scenario just a bit.
Paw Print Genetics - Genetics Dominant and recessive traits in your dogs
The truth of the matter is that you wish your bitch had dark eyes because she actually has light eyes. Other than eye color, she truly is an excellent bitch and you feel that, bred to the right dog, she can produce a wonderful litter of pups.
So, you breed her to that superior sire with the highly favored dark eyes. You must reasonably expect different results. A light eye bred to a dark eye must naturally result in a litter of puppies where all have medium brown eyes, right? If the sire is heterozygous, the puppies will either have dark eyes or light eyes.
The puppies in your litter may all have dark eyes or all may have light eyes. More than likely though, some will have dark eyes and some light eyes, but absolutely none of them will have medium brown eyes.
Canine genetics is not a science of averaging. You cannot breed a large dog to a small bitch with the goal of getting a litter of puppies that will mature to be medium in size.
Nor can you breed an aggressive dog to a timid bitch in a quest to get sound temperament. And, in no way can you breed a long, soft-coated dog to a short, hard-coated dog in hopes of getting pups with a good, medium coat. Utilizing a make-believe breed in which several color varieties are recognized may be the simplest way to demonstrate the relationship between dominant and recessive genes. Of course, some of these colors will be dominant and some recessive to one another.
Some Examples of Dominant and Recessive Traits in Selected Domestic Animals
In our breed, we find Black, Fawn and Brindle. Alleles come in pairs - one from each parent. When we write about alleles we use letters to denote them, for example a and b. Locii Genes are all tied together into a long strand of DNA.
- Dominant and Recessive Genes
- The Paw Print Genetics Blog
- Dog Genetics – Introduction to Modes of Inheritance
Each point on this strand of DNA is called a locus locii is the plural. At each locus there are two alleles forming the gene.
The alleles present at each locus are picked from a list of possible alleles, which is called a series.
There may be any number of alleles in a series, but it's usually Each locus has its own series, and the alleles in that series can only occur at that locus. Each dog has a combination of two of those alleles from the E series on its E locus. It might have one copy of e and one of E, or maybe two copies of Em. See the "Summary of series" page for a list of all the series.
On this site, I will be using the terms "series" and "locus" pretty much interchangeably. Phenotype While a genotype is the genetic makeup of an organism a technical list of locii, genes and allelesphenotype describes the effect of the genotype on the look of the organism.Incomplete Dominance, Codominance, Polygenic Traits, and Epistasis!
If we talk about a black dog with white markings then we are talking about its phenotype. There may be more than one selection of genes that could cause this phenotype.
If we talk about a KkSii dog then we are talking about its genotype, which is much more specific.
Not every colour gene in the dog's genotype will necessarily affect it's phenotype. Dominant and Recessive Although every dog carries two alleles at each locus, only one of these alleles is generally expressed meaning only one will actually be used, and the other will just effectively lie dormant. Which of the alleles is expressed depends on dominance.
The most dominant allele will always be the one which is expressed in the phenotype. A recessive allele is one which is less dominant.