Dilute / Reduced / Ice / Dominate Opal

[Nomad]

Wondering the dominance of these genes and the inheritability.

1. If a male pigeon has both Dilute and Reduced will they both express or is there a dominant of the two?

2. If a male pigeon with both dilute and reduced mates with a female without these genes will the females produced always inherit both and express which ever is dominate? Will the males produced always carry both?

3. Can a pigeon carry the ice gene and not express it? Or look like it doesn't express it? I know its an autosomal dominate trait so it should express.

4. Same question as above but regarding Dominate Opal.\

The idea of a pigeon being hetero for recessive mutations, such as, recessive red but showing some traits baffles me as I'm still learning. Or how an ash red / blue recessive bird will have black flecking due to the blue recessive color. Wish there was a place to see what all the characteristics of hetero recessive mutations are on a pigeon.

Thanks again.

[AdamArcher]

First, it is important to remember that you can only compare the dominance of mutations at the same locus. For example, you can say "dilute is recessive to pale", but you cannot compare dilute and reduced. They are on the same chromosome, and very closely linked, but are not alleles at the same locus.

Your questions:

1/ If the cockbird is homozygous for both, yes, he will express both.

2/ Again, if he is homozygous for both, yes, he will transmit them both to all his children and the young hens will express both.

3/ Ice is incomplete dominant, so a bird cannot have the gene without showing it, but a homozygous Ice pigeon will express much better than a heterozygous ice.

4/ No, Dominant Opal will be expressed if the pigeon carries the gene.

Things aren't always as "black and white" as we'd like. As you've noticed, a mutation we consider "recessive" can sometimes have a small effect even when heterozygous.

[Nomad]

Thanks for clearing that up Adam. I have a dominate opal cock I'm wanting to breed but don't want to accidently breed Dominate Opal to Dominate Opal. I also have the opportunity to pick up a cock expressing Dilute & gimple but carries Reduced and a reduced hen so was trying to figure it out. Lol.

Thanks again.

[paulh]

3. Can a pigeon carry the ice gene and not express it? Or look like it doesn't express it? I know its an autosomal dominant trait so it should express.

The term you are looking for is epistasis. The word's verb form is "epistatic", as in one mutant gene is epistatic to another mutant gene. Epistasis occurs when the action of a mutant gene at one locus prevents or masks the expression of a mutant gene at another locus. For example, the albino gene puts a block in the biosynthetic pathway producing color. A homozygous albino pigeon with no other mutant genes is white with pink eyes. That albino pigeon could have a spread mutant gene, a T-pattern mutant gene, a dominant opal mutant gene or a combination of all of them. The combination of genes still results in a pigeon that is just white with pink eyes.