Reelin is a glycoprotein secreted by specific neuronal populations of the adult and developing nervous system of vertebrates. The morphological abnormalities in the brain of reeler, the Reelin deficient mutant mice, indicate that Reelin is essential for the brain morphogenesis. However, biochemical function of Reelin signal is not well understood. Here, we examined possible function of Reelin signal in regulation of gene expression by performing a microarray analysis. We found that expression level of a mouse homologue of Strawberry Notch (mSno1) is markedly reduced in the reeler embryos. In situ hybridization showed that mSnol is expressed in the developing nervous system colocalizing with expression of ApoER2, a Reelin receptor. Treatment of P19 cells with Reelin protein enhanced mSno1 expression. Overexpression of ApoER2 with Reelin treatment gave a synergistic effect on mSno1 expression level. These observations suggest that Reelin signal is involved in embryonic expression of a novel vertebrate gene, mSnol. (c) 2006 Elsevier Inc. All rights reserved.