Das P, Mohanty-Hejmadi P
Department of Zoology, Utkal University, Bhubaneswar, Orissa, India.
Cells Tissues Organs. 1999;164(2):90-101. doi: 10.1159/000016646.
Vitamin A is a very common teratogen causing severe embryonic malformations and changes in pattern formation in amphibians. The effects of vitamin A include the induction of duplication of skeletal structures in the anteroposterior, proximodistal and dorsoventral axes. The purpose of this investigation was to study the histological changes in the regenerating tail of the tadpoles of Polypedates maculatus by treatment with vitamin A. The histological changes brought about by vitamin A included the development of multilayered epidermis and thickened basement membrane, enlargement of the notochord and the nerve cord and the clumping of muscles. In addition, single, paired and supernumerary homeotic limbs were visible from day 20 onwards at ectopic sites. Initially, the limb consisted of only procartilage cells. Muscles and digits appeared from day 48 onwards. In contrast, such observations were not found in the control tails. The significance of such changes is discussed.
维生素A是一种非常常见的致畸剂，可导致两栖动物出现严重的胚胎畸形和模式形成变化。维生素A的作用包括诱导骨骼结构在前后轴、近端远端轴和背腹轴上的重复。本研究的目的是通过用维生素A处理来研究斑腿泛树蛙蝌蚪再生尾的组织学变化。维生素A引起的组织学变化包括多层表皮的发育和基底膜增厚、脊索和神经索增大以及肌肉结块。此外，从第20天起，在异位部位可见单个、成对和多余的同源肢体。最初，肢体仅由原软骨细胞组成。肌肉和指从第48天起出现。相比之下，在对照尾中未发现此类观察结果。讨论了此类变化的意义。
