Fig. 3. Preaxial polydactyly induced by a dHAND mutant protein lacking the N-terminal transcription activation domain. F₀ transgenic mouse embryos were sacrificed at E16.5 and limbs were stained for bone and cartilage. (A) Limb from a wild-type nontransgenic embryo. Embryos harboring prx-dHAND (B) and prx-1-90 (C) transgenes showed preaxial polydactyly. All panels show forelimbs. Ectopic digits are indicated with an asterisk.