Inheritance of white colour in the boxer breed
Author: Natacha Moscoso There appears to be some controversy among fanciers regarding the white markings issue in the boxer breed, particularly as they relate to the all-white boxer. White puppies are often found in litters, much to the dismay of breeders - especially when they turn out to be deaf, a not uncommon occurance.
I think a bit of theory about the mode of inheritance of white could be useful:
The allele for solid colour (brindle or fawn) is 'S' (dominant).
The allele for white markings is 'sw' (recessive).
So, genetically, our Boxers can be:
'S S' (genotipe solid)
'S sw' (genotipe flashy)
'sw sw' (genotype white)
Thus, the results of the "allowed" bredings are:
1) 'S S' x 'S S' = 'S S', 'S S', 'S S', 'S S'
(solid x solid = 100% solid puppies)
2) 'S S' x 'S sw' = 'S S', 'S sw', 'S S', 'S sw'
(solid x flashy = 50% solid, 50% flashy)
3) 'S sw' x 'S sw' = 'S S', 'S sw', 'S sw', 'sw sw'
(flashy x flashy = 25% solid, 50% flashy, 25% white)
So the first two types of breedings *never* produce white puppies.
White markings above the cracks of the toes (which usually go hand-in-hand with white markings on the face) "betray" the flashy Boxer (genotype 'S sw').
There are of course other alleles that affect the whole colour pattern of our Boxers, like those controlling the black mask, fawn or brindle colour, size of the white markings, etc., but they do not affect the main issue we are discussing now.
I hope this explanation can help those who want to be able to avoid producing white puppies.
Natacha Moscoso
Urkabustaiz'tar Boxers
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