Blues and livers are both double recessive genes, which means
that BOTH parents must each carry a copy of the blue or liver gene in order to produce either
a blue or a liver. For the sake of keeping this as simple as possible so not to cause too much
confusion, we will talk about this gene in the form of a solid blue German Shepherd and a Solid
black German Shepherd. When you see a solid black GSD Icon with a blue outline, that dog is a blue
carrier. A blue GSD icon is a blue; a black GSD is a black dog that does not carry the blue gene.
The genetic code for a blue is dd for the word dilute since the blue gene is a dilute gene of the
color black (not from the solid black pattern, but the black color that you see in a standard GSD such
as black & tan saddle back or a black sable). This gene dilutes the black gene giving the dog an overall
dark gray or dusty light gray where the black should be. The dilute gene also affects the pigment thus turning
the black noseleather to a gray noseleather and turning the eyes to a lighter color.
The blue gene is passed from generation to generation by carriers, this is what's called a recessive gene. Both parents
must carry the gene in order for there to be a blue puppy in the litter. A blue carrier bred to a non carrier
can pass the blue gene to its progeny who in turn pass the blue gene on. The graph below demonstrates what happens
when two carriers meet. The code for a non carrier is DD, and the code for a carrier is Dd. On the graph you'll see
a black dog with a blue outline around it, this is a blue carrier. However in real life, there is no way to tell if a dog
is a blue carrier unless surprise blue pups pop out or bred to a blue to see if there are any blue pups in the litter. The second
graph demonstrates what happens when a blue is bred to a blue carrier. The third graphs demonstrates what happens when a blue is bred to
a non carrier which as you can see results in ALL the puppies becoming blue carriers.
The graph below demonstrates what happens when a blue is bred to a blue carrier. As you can see
ALL the pups are either blues or blue carriers.
Don't see all the links? Put your cursor on the
blue dog, if that doesn't work try the other one : )
