Thaller C, Eichele G
Department of Cellular and Molecular Physiology, Harvard Medical School, Boston, Massachusetts 02115.
Nature. 1990 Jun 28;345(6278):815-9. doi: 10.1038/345815a0.
There is increasing evidence that retinoic acid is a morphogen involved in vertebrate development. This evidence comes in part from studies of the chick wing bud, in which local application of all-trans-retinoic acid results in a duplication of the digit pattern along the anteroposterior axis. Retinoic acid may be only one of several morphogenetic signalling compounds required for limb pattern formation. To identify novel morphogenetically active compounds, fractionated extracts of whole chick embryos were tested for their ability to induce digit pattern duplications. We describe here the isolation of a new activity present in the limb bud, which we have identified as all-trans-3,4-didehydroretinoic acid. The 3,4-didehydroretinoic acid is generated in situ from retinol through a 3,4-didehydroretinol intermediate. We show that 3,4-didehydroretinoic acid and retinoic acid are equipotent in evoking digit duplications. These findings suggest that there are at least two endogenous retinoids with morphogenetic properties in the chick limb.
越来越多的证据表明，视黄酸是参与脊椎动物发育的一种形态发生素。这一证据部分来自对鸡胚翅芽的研究，在该研究中，局部应用全反式视黄酸会导致沿前后轴的指型重复。视黄酸可能只是肢体模式形成所需的几种形态发生信号化合物之一。为了鉴定新的具有形态发生活性的化合物，对整个鸡胚的分级提取物诱导指型重复的能力进行了测试。我们在此描述了从肢芽中分离出一种新的活性物质，我们已将其鉴定为全反式3,4-二脱氢视黄酸。3,4-二脱氢视黄酸是通过3,4-二脱氢视黄醇中间体由视黄醇原位生成的。我们表明，3,4-二脱氢视黄酸和视黄酸在诱发指型重复方面具有同等效力。这些发现表明，在鸡的肢体中至少有两种具有形态发生特性的内源性类视黄醇。
