Fig. 1

hb-egf genes are induced in zebrafish spinal cord after injury.

a Strategy used to identify regulators of spinal cord regeneration. b, c In situ hybridization for hb-egfa and hb-egfb on longitudinal sections of zebrafish spinal cord at 1 and 2 wpi, and in sham-injured controls. Dashed lines delineate spinal cord. d Sections of spinal cord tissue indicating hb-egfa:EGFP BAC reporter expression (green) in sham, 1 and 2 wpi animals. Acetylated α-Tubulin (red) stains axons. e EdU (red) incorporation assay for cell cycling at 1 wpi in transverse sections of hb-egfa:EGFP spinal cord. f Assays for Sox2 (white) expression at 1 wpi in transverse sections of hb-egfa:EGFP spinal cord. g Cross-section of hb-egfa:EGFP spinal cord at 1 wpi showing hb-egfa expression in ependymoradial-glial cells. GFAP (magenta) stains glial cells. Dashed box is magnified at bottom. h Expression of hb-egfb^EGFP in sham injured and injured adult spinal cords at 1 and 2 wpi. i Longitudinal sections of spinal cord indicating expression of Erbb4 receptor (cyan) after sham injury or at 1 wpi. j Transverse sections of adult spinal cord showing expression of egfra mRNA by in situ hybridization after sham injury or at 1 and 2 wpi. N = 3 in (b–d) and (g–j); N = 2 in (e, f). Asterisks in (j) indicate central canal. Dashed area in (e, f) indicate regions magnified. Scale bars 200 μm in (b–d, h, i); 100 μm in (g, j); 50 μm in (e, f). d dorsal, v ventral, r rostral, c caudal.