<i>Prom1</i> expression in developing and adult mouse CNS.

<p>A. RNA in situ hybridization showing high <i>Prom1</i> expression in the ventricular zone (vz, arrows) of the prenatal brain and spinal cord (a). Levels decrease over time except in the floor plate (fp). In the cerebellum (b) <i>Prom1</i> is highly expressed in the caudal and rostral rhombic lips (rl, cRL, rRL) while postnatal expression is most intense in rare cells of the white matter (hi, arrows) and the internal granule layer (igl). In postnatal brain (c) expression is conserved at low levels in the stem cell niches (svz and sgz) but is highest in single cells within white matter (wm, red arrows). B. In adult brain <i>Prom1</i> RNA is highest in single, widely distributed cells (arrowheads) in the corpus callosum (a, d), cerebellum (f), gray matter (e) and only rarely in SVZ (b) and the SGZ (c) stem cell niches. Semi-quantitative RT-PCR of microdissected white and grey matter regions from 3 different mice (g) validate high <i>Prom1</i> levels in white matter relative to gray matter and whole brain (p = 0.05) (h). Mouse liver acts as a low level reference tissue. The differential level of <i>Prom1</i> is similar to the oligodendroglial marker <i>Olig2</i> (i). ge: ganglionic eminence; ml: molecular layer; gm: grey matter; hp: hippocampus; gcl: granule cell layer; sgz: subgranular zone; cc: corpus callosum; lv: lateral ventricle; ep: ependymal layer.