DYSTROPHIN LOCALIZATION AND GENE-EXPRESSION IN THE DEVELOPING NERVOUS-SYSTEM OF THE CHICK

The presence and distribution of dystrophin was studied in selected ar eas of the chick embryo nervous system and in primary cultures. Dystro phin was examined at the protein level by immunocytochemistry and at t he transcriptional level by a semiquantitative reverse transcriptase-p olymerase chain reaction analysis, Immunofluorescence staining shows t hat dystrophin is present early during embryogenesis in dorsal root ga nglia, spinal cord, and ciliary ganglia and colocalizes with neurofila ment subunits, Cultured dorsal root ganglion, spinal cord, and ciliary ganglion neurons show immunoreactivity for dystrophin, both in cell b odies and along fibers, Dystrophin mRNA level in ciliary and dorsal ro ot ganglia is higher than in spinal cord throughout development and sh ows a tissue-specific pattern of expression, In primary cultures of do rsal root ganglia and ciliary ganglia, dystrophin mRNA level increases with time in vitro, However, in spinal cord cultures, dystrophin mRNA drastically decreases with time in vitro, but it is significantly inc reased when embryonic muscle extract is added to the cultures, Our res ults show that dystrophin is present in neurons from different areas o f embryonic chick nervous system and that its mRNA level is developmen tally regulated both in vivo and in vitro. (C) 1998 Wiley-Liss, Inc.