A bow tie indicates that there is only one dominant gene for naked neck.
This is from wikipedia:
"The naked neck trait which this breed is controlled by an incompletely dominant allele (Na) located near the middle of Chromosome 3. Since this allele is dominant individuals which are either homozygous dominant (Na/Na) or heterozygous (Na/na+) will exhibit the naked neck characteristic though the heterozygous individual will exhibit less reduction in feathering - true breeding members of the breed must then be homozygous dominant, and all individuals in the recognized breed must be also.
And this is from the ultimate fowl site:
"How can you tell a Na/na bird from a Na/Na bird? Actually, it is fairly easy. The Na/Na bird has either no 'bow tie' or a very small one made up of just a few feathers. On the other hand, the Na/na bird, that is a naked neck, will have a rather large 'bow tie."
Another strange thing with the double dominant naked neck gene is that it causes a larger breast percentage and thin skin. This is why the Turken is labeled as a good non-broiler meat bird, but this trait was only seen in homozygous Turkens.
"Scientific studies have indicated that the naked neck gene (Na) improves breast size and reduces heat stress in chickens of non-broiler breeds which are homozygous for the trait."
