In situ hybridization of cyp19a1b mRNA combined to BLBP (Brain Lipid Binding Protein) immunohistochemistry confirms the radial glial nature of the aromatase-positive cells.

A, D, G: Cyp19a1b mRNA in the brain of the Japanese eel as revealed by in situ hybridization in the post-commissural nucleus of the subpallium (Vs), the magnocellular preoptic nucleus (PM) and the parvocellular preoptic nucleus (PP). Note that the signal is consistently restricted to the regions adjacent to the ventricles. Bar  = 15 μm B, E, H: BLBP protein in the brain of the Japanese eel as revealed by immunohistochemistry on the same sections than in A, D and G. One can see that immunoreactive cells have their nuclei along the ventricles and long processes running laterally. Bar  = 25 μm C, F, I: Merges showing overlapping (yellow color) of cyp19a1b mRNA and BLBP protein in the brain of the Japanese eel as revealed by immunohistochemistry on the same sections than in A, D and G. Only the radial processes do not show co-expression. Bar  = 20 μm.