Silkie the "SHH" gene, called the ZPA Regulatory Sequence (ZRS). This causes ectopic "SHH" expression in the anterior of the developing limb bud, leading to increased tissue growth and digits. While the feet of the Silkie display polydactyly, the wings have the standard tridactyly (three digit) arrangement. The Japanese Silkie initially develops additional digits in the wing as an embryo, but these are lost prior to hatching. The genetic cause behind Silkie polydactyly differs from those that cause polydactyly in the Dorking chicken breed, which is due to ectopic "FGF4" expression in the AER, with ectopic "SHH" a secondary effect. The
The Bird in a Cage The Bird in a Cage The Bird in a Cage, or The Beauties is a Caroline era comedy written by James Shirley, first published in 1633. The play is notable, even among Shirley's plays, for its lushness — what one critic has called "gay romanticism run mad." The play was licensed for performance, under the title "The Beauties," by Sir Henry Herbert, the Master of the Revels, on 21 January 1633. It was published in quarto in the same year, printed by B. Alsop and T. Fawcet for the bookseller William Cooke. The title page of the 1633 quarto states