lethal genes in poultry
not much to do ourside so thought I would post a couple interesting poultry items
Poultry(occurs in other species also) carry some genes which are lethal; some lethal genes are heterozygous(1 copy) and the bird with this gene will not survive.
other dominant lethal genes require 2 copies for death to result.
The creeper gene(Cp) as in Japanese bantams and the ear tuft gene((Et) as in the Araucana are examples where 2 copies assure death but 1 copy has an effect on the offspring for that genes trait.
Other genes such as frizzle (F) cause a defect in feather structure and also are connected to other problems such as enlarged heart,spleens and the gizzard. The (Lav) lavender gene is associated with poor feather quality, the rosecomb(RR_ gene can be associated with low fertility in certain rosecomb breeds.
Many times the chicken can function normally with these deletrerious and lethal genes in a hetero state and are used to create breeds. The japanese bantam, the Frizzle, The Araucana, are just a few.