Can Two Light Colored Dogs Have Black Puppies?

In order to answer the question whether two light colored dogs can have black puppies, it is first important to understand the genetics of color inheritance in animals. Geneticists have located several places on chromosomes that determine the color patterns in dogs. These are known as loci and each one is responsible for various traits. The loci influence the way that the two main color pigments are distributed and the combination of all the loci working together produces the ultimate color of the dog. The interactions of these genes is very complex and some dogs may have hidden colors that only express themselves in their puppies.

  1. The Extension Gene

    • A gene known as the extension gene, or MC1R, is responsible for producing pigment. The dominant form of the gene, known as the "E" allele, allows the dog to produce a black pigment, while the recessive form of the gene, known as the "e" allele, produces a yellow pigment. Dogs that have two copies of the recessive "e" will have coats that are either yellow, orange or red.

    Color Inheritance

    • In order for a dog to have a pure, solid, yellow coat color, it must receive the recessive gene that codes for yellow from both of its parents. If it receives a dominant gene from one parent and a recessive gene from the other parent, then the puppy will have a black coat. It is helpful to think of the dominant form of the gene as the more powerful one, while the recessive gene is weaker and will only be expressed if there are two of them.

    B, K, and A Loci

    • Labrador retrievers, which are black, brown or yellow, are a good breed to look at when trying to understand the genetic inheritance of color. For example, the difference between a black Labrador and a yellow one is very obvious. The black Labrador has at least one dominant form of the "E" allele while the yellow one must have two recessive "e" alleles. In other types of dogs, the color distinction is not always as obvious.

      Besides the Extension gene, there are four other genes that are involved in deciding what the color of a dog's coat will be. These are the A, K and B loci. However, dogs that have two recessive "e" alleles will always be yellow in coat color. Dogs that have a dominant "E" allele with a recessive "e" allele or that have two dominant "E" alleles will have a variety of differences in their coat colors, depending on what role the other three genes are playing.

    Puppy Color

    • If both parent dogs have yellow coats, then they will not produce a black puppy. This is because they both have two sets of recessive genes coding for yellow or orangey-red coat colors. The offspring receive a recessive gene from each parent and will therefore have two recessive genes that must be expressed as a yellow or orangey-red colored coat.