(Genetics Symbol - In)
Partial dominance means that the mutation shows up in a different form when in a heterozygous state than when in a homozygous one. In the case of indigo, a heterozyous bird has bronzy wing bars, a somewhat washed out tail bar, usually darker rump and neck blend - indigo colored. In the homozygous state, a bird can actually be mistaken for an Ash-red, though the neck blend and rump tend to be darker in homozygous indigos than in Ash-reds.
Since Indigo is not sex-linked, it makes no difference if the cock or the hen is carrying it for these tables to show percentage expectations. Remember, these ARE just expectations. You may well get five wild-type young in a row from the first mating or five homozygous Indigo. However, over the course of about 100 or more birds bred, the percentages will fall out into just about those predicted.
|In||In In||In +|
|+||In +||+ +|
By adding Spread to the In+ birds, you get andalusian. Andalusian is simply a fanciers term for the combination effect of heterozygous Indigo with either homozygous or heterozygous spread. Homozygous indigo with spread is NOT andalusian either in name or color.
In//+ x +//+
50% Heterozygous indigo.
50% non-Indigo (wild-type)
In//In x In//In
In In In In In In In In In In In In
100% Homozygous Indigo
Homozygous Indigo x Wild-type (non indigo)
In//In x +//+
+ + In In + In + In In + In +
100% heterozygous indigo
(If you happen to have mated the homozygous indigo parent to a homozygous spread bird, then all the youngsters would be andalusian colored (heterozygous indigo and heterozygous spread)