Pea Comb & Blue Egg Gene

[nicalandia]

can you @nicalandia please explain it then in terms someone not versed in modern genetics can understand? It is looking like 2 of my araucana x SFH crosses have single combs, and 2 of them pea combs. I have been reading chicken genetics threads and papers, and it is really hard for me to follow. A lot has changed since I did A level biology!

The pea comb allele and the Oocyan allele are located on chicken chromosome 1,

In the case of Pea comb blue egg layers the dominant Oocyan( O for the mutation and o+ for the recessive wildtype non-blue eggshell) is closely linked to the Pea Comb. In a cross between Pure Blue Egg Layers like Ameraucanas and a non-blue egg shell laying strain with single comb the cross will be P/p+(where P is for Pea Comb and p+ for the wildtype single comb) and O/o+(where O is the Oocyan mutation and o+ the wildtpe non-blue eggshell) so All of the F1s will lay a light blue egg shell color. If the F1 hens are further crossed with a non-blue egg shell rooster(o+/o+) the cross will be 50% P/p+ and p+/p+, knowing that the blue egg shell is closely linked to the Pea Comb by 3-5 centimorgan there is a 95% chance that each Pea Comb hen will lay bluish colored eggs and that 95% of the single comb hens of that cross(Single comb non-blue eggshell rooster with F1 O/o+ hens) will lay White/Tinted eggs.

Both genes P and O are Closely linked this means that they will not segregate independently from each other so a Punnett Square will not work here. But there is a chance of cross over(genetic recombination during meiosis) and the Single Oocyan mutation can cross over to the Single Comb p+ mutation linking itself to it(the case of single comb blue egg layers like CCL and Blue Isbars)

Chances are that your single comb Easter Eggers(about 95% chance) will lay pinkish eggs and that the Pea combed ones will lay Bluish/greenish eggs

 

[Perris]

The pea comb allele and the Oocyan allele are located on chicken chromosome 1,

In the case of Pea comb blue egg layers the dominant Oocyan( O for the mutation and o+ for the recessive wildtype non-blue eggshell) is closely linked to the Pea Comb. In a cross between Pure Blue Egg Layers like Ameraucanas and a non-blue egg shell laying strain with single comb the cross will be P/p+(where P is for Pea Comb and p+ for the wildtype single comb) and O/o+(where O is the Oocyan mutation and o+ the wildtpe non-blue eggshell) so All of the F1s will lay a light blue egg shell color. If the F1 hens are further crossed with a non-blue egg shell rooster(o+/o+) the cross will be 50% P/p+ and p+/p+, knowing that the blue egg shell is closely linked to the Pea Comb by 3-5 centimorgan there is a 95% chance that each Pea Comb hen will lay bluish colored eggs and that 95% of the single comb hens of that cross(Single comb non-blue eggshell rooster with F1 O/o+ hens) will lay White/Tinted eggs.

Both genes P and O are Closely linked this means that they will not segregate independently from each other so a Punnett Square will not work here. But there is a chance of cross over(genetic recombination during meiosis) and the Single Oocyan mutation can cross over to the Single Comb p+ mutation linking itself to it(the case of single comb blue egg layers like CCL and Blue Isbars)

Chances are that your single comb Easter Eggers(about 95% chance) will lay pinkish eggs and that the Pea combed ones will lay Bluish/greenish eggs

thank you SO MUCH @nicalandia Finally I understand!