Abstract
The homeodomain transcription factor Nkx2.1 controls cell differentiation of telencephalic GABAergic interneurons and oligodendrocytes. Here, we show that Nkx2.1 additionally regulates astrogliogenesis of the telencephalon from embryonic day (E) 14.5 to E16.5. Our work aims to identify the different mechanisms by which Nkx2.1 controls telencephalic astrogliogenesis. In Nkx2.1-/-, a drastic loss of astrocytes is observed which is not related to cell death. In vivo analysis using BrdU incorporation reveals that Nkx2.1 affects the proliferation of ventral neural stem cells that generate early astrocytes. In vitro neurosphere assays show that Nkx2.1 additionally affects the differentiation step of Nkx2.1-derived astrocytes. Chromatin immunoprecipitation and in vitro co-transfection studies of a Nkx2.1-expressing plasmid indicate that Nkx2.1 binds to the promoter of astroglial differentiation gene GFAP, and regulates its expression. Hence, Nkx2.1 controls astroglial production spatiotemporally in embryos by regulating stem cell division and specification of the contributing Nkx2.1+ precursors.
Abbreviations list
- AEP
- Anterior entopeduncular area
- BrdU
- 5-bromo-2’-deoxyuridine
- CC
- Corpus callosum
- CCi
- Cingulate cortex
- CI
- Cingulate bundle
- Cre-ERTtm
- Tamoxifen inducible Cre recombinase fused to the ligand binding domain of the estrogen receptor
- Cspg4
- Chondroitin sulfate proteoglycan 4 (also known as NG2)
- DIV
- Day in vitro
- E
- Embryonic day
- EGFP
- enhanced green fluorescent protein
- EYFP
- enhanced yellow fluorescent protein
- GABAergic
- γ-aminobutyric acidergic
- Gad1
- Glutamate decarboxylase 1 (also known as GAD67)
- Gad1-EGFP
- Gad1-EGFP knock-in mouse
- GFAP
- Glial fibrillary acidic protein
- GLAST
- Glutamate-aspartate transporter
- GP
- Globus pallidus
- HIC
- Hippocampal commissure
- IG
- Indusium griseum
- IRES
- Internal ribosome entry site
- IZ
- Intermediate zone
- KO
- knockout
- LGE
- Lateral ganglionic eminence
- LH
- Lateral hypothalmus
- Lhx6
- LIM homeodomain (LIM-hd) gene
- LPOA
- lateral preoptic area
- LV
- Lateral ventricle
- MGE
- Medial ganglionic eminence
- MZ
- Marginal zone
- MZG
- Midline zipper glia
- NG2
- Neuron-glial antigen 2
- Ngn2
- Neurogenin2
- Nkx2.1
- NK2 homeobox 1
- Nkx2.1-Cre
- Mouse with the Cre recombinase under control of the Nkx2.1 promoter
- Olig2
- Oligodendrocyte transcription factor
- pCAG
- promoter constructed from following sequences: (C) cytomegalovirus early enhancer element, (A) promoter, the first exon and intron of chicken beta-actin gene, (G) the splice acceptor of the rabbit beta-globin gene
- POA
- Preoptic area
- RMS
- Rostral migratory stream
- Rosa-EYFP
- Rosa26-lox-STOP-lox-EYFP reporter mouse
- S100ß
- Small EF-hand calcium and zinc binding protein
- SEP
- Septum
- ST
- Striatum
- SVZ
- Subventricular zone
- TS
- Triangular septal nucleus
- TUNEL
- Terminal deoxynucleotidyl transferase dUTP nick end labeling
- VZ
- Ventricular zone
- WT
- wild-type
