Final answer:
The inheritance pattern for white coloring in dogs involves multiple alleles, leading to different phenotypes based on a dominance hierarchy. This is not to be confused with polygenic inheritance, as it involves multiple forms of a single gene instead of multiple genes. Details from Labrador retrievers' coat color genetics provide an example of epistasis rather than multiple alleles.
Step-by-step explanation:
The inheritance pattern for white coloring in dogs is due to the existence of multiple alleles. In general, the term refers to the phenomenon where a single gene has more than two allelic forms within a population. For example, in rabbits, the gene for coat color has four alleles, which produce various phenotypes based on dominance hierarchies.
This is similar to the case in dogs, where combinations of alleles result in different coat patterns like solid coat, Irish spotting, piebald spotting, and white coats. However, this is not an example of polygenic inheritance, in which traits are controlled by multiple genes (as in the case of human skin color), rather it is a case of multiple allelic inheritance.
In the context of Labrador retrievers, fur color is controlled by two alleles, E and B. Interaction between these alleles reveals another genetic concept called epistasis, where one gene interferes with or masks the expression of another gene. For example, if a dog has the genotype 'ee', it will be yellow regardless of the B allele, demonstrating the epistatic effect. The 'E' gene essentially determines whether or not eumelanin (black or brown pigment) can be expressed.
Analogous to the example of rabbit coat colors, the white coloring inheritance in dogs showcases how complex genetic relationships can define an organism's phenotype. The hierarchy in dominance among alleles influences which specific coat color will be expressed in the offspring of dogs.