Spatial and temporal expression of RP58, a novel zinc finger transcriptional repressor, in mouse brain.

RP58, a novel zinc finger protein containing a POZ domain, is a sequence-specific transcriptional repressor. To understand the role of this protein, we examined RP58 gene expression in the developing mouse brain by quantitative polymerase chain reaction (PCR) and in situ hybridization. RP58 mRNA expression was detected at embryonic day (E) 10 in the neuroepithelium, and subsequently in the ventricular zones of the cerebral cortex in the E12 embryo. Strong expression was observed in the preplate in the cerebral cortex from this stage onward. High levels of expression continued to be detected in the cortical plate and subventricular zone of the neocortex, hippocampus, and parts of the amygdala, but not in the thalamus or striatum. These results suggest that RP58 plays a crucial role in neuronal proliferation, migration, and differentiation in the developing cerebral cortex. RP58 is also expressed in the adult mouse neocortex, hippocampus, parts of the amygdala, and granule cells in the cerebellum. Double in situ hybridization using GAD67 or VGLUT1 probes revealed that RP58 is expressed in glutamatergic excitatory neurons.