coat genetics

genetics of coats in the Chow Chow breed

This page is based on the chapter about coat from the Dutch book "De Chow Chow in Nederland", written by Janneke Leunissen - Rooseboom, with my own experience and thoughts added.
I am always interested in thoughts others might have about this topic.

genetics of coat length

The genetics of the coat length seem very simple, smooth is the dominant factor and this is usual true. Out of two roughs come only roughs and out of smooths you can get both smooth and rough.
But there are a few cases of smooths born out of two roughs, and they gave smooth coats to their offspringg. These cases are too many to ignore this fact, or to call them random mutations.
The difference between rough and smooth is not always very clear too, there are smooths with a longer smooth coat and there are roughs with a shorter rough coat.
It could be possible that the smooths with a longer coat are the heterozygoot smooths, so Kk could be an indermediate coat. But our females Pandora, Callisto and Chimay were heterozygote (in their litters were both smooths and roughs), and they have no long smooth coat, in Pandora's offspring are 3 smooths with the longer smooth coat.
Possible there is an yet unknown gene involved, that influences the coat length making it longer or shorter. Thus resulting in short coated smooths and longer coated smooths; shorter coated roughs and longer coated roughs.

So the exact genetic make up is yet unknown, for the examples below I work with the simple version: the smooth gene (L) is dominant, the rough gene (l) is recessive.
This gives us three possible genetic varieties:
LL both genes smooth = homozygoot smooth
Ll one gene smooth and the other rough = heterozygoot smooth
ll both genes rough = homozygoot rough

possible outcomes in breeding

A homozygoot smooth (LL) gives in all cases only smooth pups:
  LL × ll gives 100% Ll
  LL × Ll gives 50% LL and 50% Ll
  LL × LL gives 100% LL

A heterozygoot smooth (Ll) can give smooth and rough pups:
  Ll × ll gives 50% Ll and 50% ll
  Ll × Ll gives 25% LL and 50% Ll and 25% ll

A rough (ll) × rough (ll) gives 100% rough (ll)

color and coat

this page was updated at
March 4th, 2012
© Anita Meulstee

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