Figure 1From: Genetic lineage tracing defines distinct neurogenic and gliogenic stages of ventral telencephalic radial glial developmentGlast bacterial artificial chromosome (BAC) transgenic mice recapitulate the spatiotemporal pattern of endogenous GLAST (glial high affinity glutamate transporter) expression. (e-v") In situ hybridization (ISH) (a-d) and immunofluorescent staining (e-v) of Glast::Cre (a-i) and Glast::eGFP (j-v) BAC transgenic mice. Cre mRNA in the ganglionic eminences (a), thalamus (b), spinal cord (c), and cerebellum/hindbrain (d) was completely restricted to the ventricular zone, with no neuronal expression detected at any age examined. The Glast::Cre transgene also recapitulated endogenous GLAST expression gradients (compare (c) and (r)). Postnatally, Cre immunoreactivity (green) (e-i) was restricted to astroglia. Shown are cortical GLAST+ astrocytes (f), striatal BLBP+ astrocytes (g), and cerebellar Bergmann and astroglia (h,i); no colocalization with CALB1+ Purkinje cells was observed (i). Double immunofluorescent staining of Glast::eGFP embryos for GLAST (red) and enhanced green fluorescent protein (eGFP; green) showed that the BAC transgene drives expression in essentially all GLAST+ radial glia (j-q); the notable exception to this was the spinal cord floorplate where no transgene expression was detectable (r-t). Postnatal expression was similarly restricted to astroglia (u.v). Scale bars: 200 μm (c,d,e,h,r,s); 100 μm (b); 75 μm (a,j-l); 50 μm (f,n-p,t); 40 μm (m); 35 μm (u); 25 μm (g,i,q,v). E, embryonic day.Back to article page