Hprt1^{tm4(Ple88-EGFP)Ems}

The Ple88-EGFP transgene (pEMS1375) was designed with a Ple88 minipromoter (GFAP-A; a 2210 bp promoter region of the human glial fibrillary acidic protein (GFAP) gene) upstream of a minimal F5 mutant-frt site, an enhanced green fluorescent protein (with mutated TAA->TTA stop), a nuclear localization signal, a second minimal frt site, an SV40 early polyA signal, and a human HPRT complementary sequence (containing exon1, intron1, exon2, and part of intron2). This construct was targeted as a single copy knockin to the Hprtb-m3 mutant locus on the X chromosome. In most cells, EGFP immunoreactivity fills the cell bodies and processes; revealing their full morphology and indicating the glial nature of the cell types. There is EGFP expression in A): astroglial-like cells in the forebrain and cortex, hippocampus and alvius, the cerebellar white matter, as well as the midbrain, brainstem, and eye, B): nascent neuronal/glial progenitor cells in the developing forebrain (including rostral cortical subventricular zone and the rostral migratory stream, and C): numerous cells in the optic nerve and the proximal segment as the nerve enters the retina (much like typical astrocytic staining). While EGFP and GFAP co-expression is observed, not all EGFP+ cells are GFAP+; reflecting the possibility that the Ple88 minipromoter may express in non-glial cell types. (J:144244, J:164356)