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
What the Little Bird Told Him projecting Gotham’s season one extension onto this episode–or maybe I’m putting too much stock into the number “12” that designates this episode–but “What The Little Bird Told Him” sure feels like a penultimate episode of television. It engages with almost all of the storylines that have been a part of this season so far (notably absent is Gotham’s most rewarding storyline to date, the continuing growth of Bruce Wayne and his badass butler Alfred) while moving its central pieces, specifically the mob bosses, into place for a finale. In any other season, this episode would set the stage for the