Abnormal limbs (abl), a recessive mutation affecting the tadpoles ofXenopus l. laevis

Summary Abnormal limbs (abl) is a recessive and semi-lethal mutation introduced by a from the laboratory stock. Brachymely, syndactyly, polydactyly and brachydactyly are the main abnormalities encountered. They occur more frequently in the forelimbs than in the hindlimbs.Acknowledgment. The authors are indebted to Prof. A.W. Blackler, Dr I. Hadji-Azimi and Mrs J. Gazel-Stock for their valuable collaboration. This work was supported by the Fonds national de la Recherche scientifique (requêtes No 3.60.68 et 3.221.73).