Fig. 5

In the dorsal spinal cord PRDM13 is required to produce the correct number of pax2+/GABAergic neurons [25]. Excitatory and inhibitory neurons of the dorsal spinal cord emerge from progenitor populations within the dorsal neural tube. Depending on the transcription factors that are expressed progenitors can become neurons in either class. To redirect cell fate such a transcription factor activates lineage specific gene expression of one lineage and represses the expression of genes in the alternate lineage. The inhibitory (GABAergic) lineage of neurons for example is specified by the homeodomain (HD) transcription factor Pax2. Pax2 and PRDM13 are required for the specification of inhibitory cell fate in the dorsal spinal cord and are direct downstream targets of Ptf1a. The excitatory (glutamatergic) lineage is specified by the HD factors Tlx1/3. PRDM13 actively represses excitatory cell fate by binding to regulatory sequences near Tlx1/Tlx3 genes, suppressing their expression. Ptf1a, a transcription activator induces factor Pax2 while suppressing the expression of Tlx1/3 which leads – through PRDM13- to an increase of inhibitory neurons at the expense of excitatory neurons. Adapted from Guo et al. [26] and Chang et al. [25]