Morphogenesis of Genetic Preaxial Polydactyly, Polydactyly Nagoya, Pdn, in Mice
1982 年 22 巻 2 号 p. 137-144
詳細
1982 年 22 巻 2 号 p. 137-144
The limb buds and foot plates of Pdn mouse embryos were examined with cartilage-stained cleared specimens, histological sections and vital-stained specimens with Nile blue A. The homozygotes could be distinguished by the external features of the foot plate from day 12 of gestation and the heterozygotes from day 14. The chondrogenesis of extra-digits could be observed as well as the normal digits on day 14 of gestation in the homozygotes. Histologically, the involution of the apical ectodermal ridge in homozygotes was delayed at the preaxial portion, as were the mesodermal condensations of digital blastema of the extra-digits. The normal patterns of physiological cell death in the apical ectodermal ridge, the deep preaxial mesoderm and preaxial marginal mesoderm were disrupted in the homozygotes. The results suggested that an absence of physiological cell death might play a significant role in the production of the preaxial polydactyly.
