Expression of Meis and Pbx genes and their protein products in the developing telencephalon: implications for regional differentiation

The Meis and Pbx genes encode for homeodomain proteins of the TALE class an d have been shown to act as co-factors for other homeodomain transcription factors (Mann and Affolter, 1998. Curr. Opin. Genet. Dev. 8, 423-429). We h ave studied the expression of these genes in the mouse telencephalon and fo und that Meis1 and Meis2 display region-specific patterns of expression fro m embryonic day (E)10.5 until birth, defining distinct subterritories in th e developing telencephalon. The expression of the Meis genes and their prot eins is highest in the subventricular zone (SVZ) and mantle regions of the ventral telencephalon. Compared to the Meis genes, Pbx genes show a broader expression within the telencephalon. However, as is the case in Drosophila (Rieckhof et al., 1997. Cell 91, 171-183; Kurrant et al., 1998. Developmen t 125, 1037-1048; Pai et al., 1998. Genes Dev. 12, 435-446), nuclear locali zed PBX proteins were found to correlate highly with Meis expression. In ad dition, DLX proteins co-localize with nuclear PBX in distinct regions of th e ventral telencephalon. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.