Unc5C and DCC act downstream of Ctip2 and Satb2 and contribute to corpus callosum formation

The pyramidal neurons of the mammalian neocortex form two major types of long-range connections—corticocortical and cortico-subcortical. The transcription factors Satb2 and Ctip2 are critical regulators of neuronal cell fate that control interhemispheric versus corticofugal connections respectively. Here, we investigate the axon guidance molecules downstream of Satb2 and Ctip2 that establish these connections. We show that the expression of two Netrin1 receptors- DCC and Unc5C is under direct negative regulation by Satb2 and Ctip2, respectively. Further, we show that the Netrin1–Unc5C/DCC interaction is involved in controlling the interhemispherical projection in a subset of early born, deep layer callosal neurons.