Ndrg2 expression in neurogenic germinal zones of embryonic and postnatal mouse brain.

N-myc downstream-regulated gene 2 (Ndrg2) is well-known for its involvement in tumor cell proliferation and differentiation. This promotes us to investigate whether Ndrg2 also functions in neurogenesis, during which some cellular events are similar to that of tumorigenesis. As the first step in exploring the role of Ndrg2 in neurogenesis, here we performed in situ hybridization with a Ndrg2-specific probe to examine Ndrg2 mRNA expression in neurogenic germinal zones of embryonic and postnatal mouse brain. Our results showed that Ndrg2 mRNA was highly expressed in the cortical ventricular zone at various embryonic stages. At postnatal stages, Ndrg2 transcripts were downregulated but still abundant in the subventricular zone of lateral ventricle and subgranular zone of hippocampal dentate gyrus where persistent neurogenesis occurs in the mammalian brain throughout life. Double staining of Ndrg2 mRNA with proliferation markers BrdU and Ki67, or with neural progenitor cell marker Nestin revealed that Ndrg2 was expressed in proliferating precursor cells. Thus, abundant expression of Ndrg2 mRNA in neural proliferating cell populations indicates an important role of Ndrg2 in neurogenesis of both embryonic and postnatal mouse brain.