alpacasandchicks78
Songster
- Aug 7, 2020
- 246
- 351
- 131
Okay-- so dark gray feet on both mom and dad equals rooster?? I have two male d'uccle and she's with the gray legged one. The other d'uccle has lighter feet gray legs than the other two d'uccle. (Third one is a hen, and I keep the roosters separated.)The skin color is only sexlinked when the father has dark legs and the mother has light.
Reversing them (dark mom, light dad) gives chicks that cannot be sexed by color. You will get light legs in both genders, and you may also get dark legs in both genders if the father carries the gene for dark legs.
Genetic explanation (ignore if not interested):
This is because of the way the chromosomes work in chickens.
a male has ZZ sex chromosomes
a female has ZW sex chromosomes
dark vs. light legs is on the Z chromosome
A hen inherits Z from her father and W from her mother. She gives Z to her sons and W to her daughters. If you think about the W part, that's what determines the sex of the chicks, and it only passes from mother to daughter. Because a hen only has one Z chromosome, she shows whatever genes are on it. Whether a gene is dominant or recessive doesn't matter to a bird with only one.
A rooster inherits Z from his father and from his mother. If they match, he shows that trait (in this case, dark legs or light legs.) If the two Z chromosomes do not match, he shows whichever one is dominant (in this case, light legs.) So a dark-legged rooster must have two dark-legs genes, while a light legged rooster might have two light or one light and one dark. A rooster gives one Z chromosome to each of his chicks.
When you breed a dark-legged rooster to a light-legged hen, he gives the dark legs to every chick. Since that is the only Z chromosome his daughters have, they show dark feet. The light-legged mother gives W to her daughters (makes them female) and Z to her sons. For the sons, because they inherit dark from dad and light from mom, they show light legs (dominant trait.)
When you breed a light-legged rooster, if he has the light-legs gene on both of his Z chromosomes, he gives one to every chick. For the daughters, that is the only Z chromosome they have, so they show light legs. For the sons, because light legs is dominant, they also show light legs. This is true regardless of whether the mother has light or dark legs.
When you have a light-legged rooster that carries the gene for dark legs, he gives light legs to some chicks and dark legs to other chicks. For daughters, they show whatever leg color they got (dark or light), because they only have the one Z chromosome. For sons, if they have a dark-legged mother, they can show either leg color. Dark legs from the mother and dark legs from the father makes a dark-legged son. Dark legs from the mother and light legs from the father makes a son that shows light legs (the dominant trait.)
All the sex-linked genes work the same way. Once you know which is dominant, you can set up a sex-linked cross by using a father with the recessive trait (which will appear in his daughters) and a hen with the dominant trait (which will appear in the sons).
For other common sex-linked genes:
silver is dominant over gold
barred is dominant over not-barred
not-chocolate is dominant over chococlate
