[Effect of 5-bromodeoxyuridine in vivo and in vitro on the development of the avian skeleton].

The effects produced in vivo and in organ culture on the differentiation of the somitic mesenchyme by the thymidine analog, 5-bromodeoxyuridine, are dependant on the experimental conditions. The analog can give rise to irreversible or reversible blockade of cell differentiation or to inhibitory effects of the biosynthesis of several macromolecules normally secreted by the somitic cells. In vivo, the analog causes skeletal malformations affecting particularly the lumbo-sacral area and the hind limbs.