Neuronal lineage specificity of the doublecortin regulatory sequence ( pdcx 2kb-eGFP). (a) Schematic representation of the mouse Dcx promoter construct for reporter gene expression: black boxes (E1 and E2) represent the first two exons of the Dcx gene: the localization of putative CAAT/TATA boxes and ATG start codon are shown (b) Cerebellar Granule neurons (CGN) extracted from PND3 mice were transiently transfected with pdcx 2kb-eGFP (A-H) or pCMV-eGFP (I-P). After 72 hrs, expression of eGFP was analyzed using an inverted fluorescence microscope and compared with the neuronal cell-specific marker Dcx or astroglial cell-specific marker GFAP; DAPI was used as a nuclear counterstain. In cells transfected with the pdcx 2kb plasmid, co-expression was observed between eGFP and Dcx (A-D). No expression overlap is observed between eGFP and GFAP (E-H). Cells transfected with pCMV-eGFP plasmid (I-P) present a strong eGFP expression with Dcx (I-L) and with GFAP (M-P). Scale bar equals 50 μm. (c) E15 embryonic mouse brains were electroporated with pdcx 2kb-EGFP plasmid. After 4 days, organotypic slices were sectioned, immunostained with Dcx and counterstained with DAPI. Slices were analyzed by confocal microscopy. The insert shows the location of the microphotograph: eGFP, Dcx and their co-localization are presented. Scale bar equals 50 μm.