A mask is a specific expression of the
dark coat gene, one which expresses itself only over a certain area of the body, namely the head.
So, a dog can be a smooth coat (the dominant gene is expressed, or seen), and have a hidden
long coat gene, which it can pass on to the offspring.
UKC Champion Sky Von Barren Berg CD BN RN HIC CGC TC TDI SV A Stamp Hips and Elbows OFA Shoulders OFA Thyroid OFA Cardiac OFA Full Dentition OFA DM Normal / Normal OFA DNA Bank MDR1 Normal Von Willebrand's Negative Homozygous
short coat gene (Sky can not whelp a long coat puppy)
Female orange tabbies only happen about 25 % of the time, and require for both parents to have an
orange coat gene, so that the XX combination determines that they must be red.
But smaller breeds have their problems as well, like the Bashkir Curly where many breeders continue to use and promote the use of hairless (extreme / baldy *) horses in breeding based on the anecdote that they are homozygous for the
curly coat gene; these are horses who are defenseless to weather extremes (head & cold) and bugs (no manes, no tail hair, many times large swaths of their body hairless as well).
DNA research now gives us information about
how coat genes affect the «look» of a Goldendoodle.
The smooth
coat gene is DOMINANT (indicated by capital letters), and the long coat gene is RECESSIVE (indicated by lower case letters).
The dominant smooth
coat gene, if present, will completely hide the recessive long coat gene.