Alright, so what is the nitty gritty on coat color inheritance?
Two sets of genes, not one, control a Lab’s coloration. One set of genes controls whether the Lab will be dark (either black or chocolate) or light (yellow). Dark is dominant over light. Thus a Lab whose genotype is EE (homozygous dominant) or Ee (heterozygous) will be dark; only Labs that are ee (homozygous recessive) can be light. The second set of genes only come into play if the Lab is dark (either EE or Ee). This set controls whether the Lab is black (the dominant trait) or chocolate (the recessive trait). Thus, a dark dog (ie. EE/ Ee) that is BB (homozygous dominant) or Bb (heterozygous) will be black, while the only way a dog can be chocolate is for it to be dark (EE/Ee) AND bb (homozygous recessive). So now, the possibilities for black dogs are EEBB, EEBb, EeBB, or EeBb. The possibilities for a yellow dog are eeBB, eeBb, or eebb. And the possibilities for a chocolate dog are EEbb or Eebb. Remember that puppies will get one E/e from the dam and one from the sire, as well as one
Two sets of genes, not one, control a Lab’s coloration. One set of genes controls whether the Lab will be dark (either black or chocolate) or light (yellow). Dark is dominant over light. Thus a Lab whose genotype is EE (homozygous dominant) or Ee (heterozygous) will be dark; only Labs that are ee (homozygous recessive) can be light. The second set of genes only come into play if the Lab is dark (either EE or Ee). This set controls whether the Lab is black (the dominant trait) or chocolate (the recessive trait). Thus, a dark dog (ie. EE/Ee) that is BB (homozygous dominant) or Bb (heterozygous) will be black, while the only way a dog can be chocolate is for it to be dark (EE/Ee) AND bb (homozygous recessive). So now, the possibilities for black dogs are EEBB, EEBb, EeBB, or EeBb. The possibilities for a yellow dog are eeBB, eeBb, or eebb. And the possibilities for a chocolate dog are EEbb or Eebb. Remember that puppies will get one E/e from the dam and one from the sire, as well as one B
