Which comb type is dominant?

[happytxchick]

Is a pea comb or straight comb dominant?

Reason for asking: I have hatchlings with straight combs that have two pea combed parents. However, I've heard that pea is dominant, which wouldn't make sense in this case.

 

[patandchickens]

There are two genes involved, one for rosecombedness and one for peacombedness. In both, the single comb is the recessive version.

So, yes, pea combed is dominant over single comb.

Your hatch makes total sense, it is telling you the (fairly useful!!) information that both of the parents are heterozygous (="split") for that gene.

So, if P is the peacomb allele and p is the single-comb recessive allele, both your parent chickens are Pp. On average, one quarter of their offspring will be single-combed (pp), the rest will be peacombed. Of the pea-combed offspring, on average two thirds of them will carry the single-comb allele hidden behind the dominant P they also carry; the other third will be straight PP.

Good luck, have fun,

Pat

 

[happytxchick]

Thanks, Pat...that makes total sense! Appreciate you helping me "think" it out.

 

[BBK]

would this be the same case with a Rose comb? single comb?

thanks
melinda

 

[happytxchick]

BBK - that's what it sounds like to me. We'll see if Pat confirms.

 

[BBK]

Thanks happy...that's what I was thinking too, just wanted conformation...
melinda

 

[Sonoran Silkies]

Yes, it is pretty much the same with rose comb. Note that these are different genes, and are not the only comb genes The entire combination of comb genes determines comb appearance.

 

[BBK]

thanks...

melinda

 

[patandchickens]

Quote:
Yup, it would.

Basically, because the dominant allele can hide the presence of a recessive allele for that gene, any time you get two parents with the dominant-allele trait producing an offspring with the recessive-allele trait, you know FOR SURE that BOTH parents are heterozygous (split) for that gene.

BTW if you have a chicken with the dominant allele at *both* loci -- R_P_ -- you get a, what is it, cushion or walnut comb, I forget exactly.


Pat

 

[Sonoran Silkies]

Walnut.