Figure 1. Structure and expression of mouse Zfhx2.

(A) Structure of ZFHX2 and related proteins. ZFHX2 is a protein of 2562 amino acids containing 18 zinc fingers (green ovals) and three homeodomains (red squares). (B) Zfhx2, Zfhx3, and Zfhx4 mRNA detected by semi-quantitative RT-PCR in various RNA sources. Note that cDNAs were amplified for 30 cycles for brains of different developmental stages, whereas for 35 cycles for various adult tissues. (C–E) Expression of Zfhx2 (C), Zfhx3 (D), and Zfhx4 (E) mRNA in the parasagittal sections of an E15.5 mouse brain. These three genes were expressed in substantially similar patterns with the highest expression level of Zfhx3. (F, G) Expression of Zfhx2 mRNA (F) and the ZFHX2 protein (G) was compared on adjacent coronal sections of an E15.5 brain. mRNA expressed in the thalamic region (Th) was translated, whereas mRNA expressed in the cerebral cortex (Cx) was not translated: this situation made the expression patterns of ZFHX2 and ZFHX3 more alike in the protein level than in the mRNA level. (H–J) Expression of Zfhx2 (H), Zfhx3 (I), and Zfhx4 (J) mRNA in the coronal sections of an adult brain. Cerebral cortex (Cx), hippocampus (Hp), thalamus (Th), caudate putamen (CP). Expression levels of all three genes were decreased compared with those in the embryonic brain, but Zfhx2 maintained higher level of expression than the others. (K–P) Expression of ZFHX2 protein in the adult brain. The pyramidal layer of hippocampus (K, Py), the suprachiasmatic nucleus (L, SCN), laterodorsal thalamic nucleus (M, LD), lateral geniculate nucleus (N, LGN), substantia nigra pars compacta (O, SNc), and magnocellular part of the red nucleus suprachiasmic (P, RMC). (Q–Y) Double-color in situ hybridization with Zfhx2 and tyrosine hydroxylase (Th) probes. The Zfhx2 mRNA (red) was highly expressed in the Th mRNA (green)-positive cells in the substantia nigra pars compacta (SNc). Zfhx2 mRNA was coexpressed with Th mRNA also in the ventral tegmental area (VTA) at a slightly lower level.