Figure 5.

Sox14 expression induces Calb2 and suppresses prethalamic (pTh) GABA identity. Sox14 expression in pTh GABA progenitors results in the selective activation of the rTh subtype marker Calb2, whilst the upstream regulator of rTh identity Gata2 was not activated (A). Immunohistochemistry illustrating the co-localization of Calb2 protein in pTh progenitors expressing the transcription factor Sox14 (B). Expression of pTh progenitor markers (Dlx2 and Meis2) is reduced upon ectopic expression of Sox14(C), while the overall GABAergic identity is not affected (Gad1) (D). Schematic recapitulation of the cross-regulation of GABA subtype restricted transcription factor on the rostral and pTh sides of the zli. Gata2/3 and Dlx1/2 have similar but reciprocal roles in suppressing the alternative subtype fate. Sox14, which acts downstream of Gata2 controls transcription of a subtype marker gene: Calb2. Its ectopic expression is not compatible with that of pTh transcription factor genes (E). Scale bars: 100 μm.