A DISTAL-LESS-LIKE GENE IS INDUCED IN THE REGENERATING CENTRAL-NERVOUS-SYSTEM OF THE URODELE PLEURODELES WALTL

We report the cloning of a Distal-less-like gene (PwDlx-3) and its pat tern of expression during embryonic development and adult tail regener ation in the urodele Pleurodeles waltl. Using RT-PCR and in situ hybri dization experiments we determined that, during regeneration, PwDlx-3 is expressed in the epidermis, the cells associated with muscle masses and in the ventrolateral parts of the ependymal tube. PwDlx-3 localiz ation in the muscle masses and in cells of the ependymal tube, which g ive rise during regeneration to the ventral roots and the spinal gangl ia, suggests that this gene might be expressed in cells which have som e neural crest cell potentialities. PwDlx-3 is the first homeobox gene shown to be expressed in the regenerating spinal cord but not in the adult one and could thus be involved in the regeneration of the nervou s system.