Barhl2 limits growth of the diencephalic primordium through Caspase3 inhibition of beta-catenin activation.

Little is known about the respective contributions of cell proliferation and cell death to the control of vertebrate forebrain growth. The homeodomain protein barhl2 is expressed in the diencephalons of Xenopus, zebrafish, and mouse embryos, and we previously showed that Barhl2 overexpression in Xenopus neuroepithelial cells induces Caspase3-dependent apoptosis. Here, barhl2 is shown to act as a brake on diencephalic proliferation through an unconventional function of Caspase3.