Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:Epithelial cells possess remarkable plasticity, having the ability to become mesenchymal cells through alterations in adhesion and motility (epithelial-to-mesenchymal transition or EMT). Recent studies suggest that EMT endows differentiated epithelial cells with stem cell traits, posing the interesting question of how epithelial plasticity is properly restricted to ensure epithelial differentiation during tissue morphogenesis. Here we identify zinc-finger transcription factor Ovol2 as a key suppressor of EMT of mammary epithelial cells. Epithelia-specific deletion of Ovol2 completely arrests mammary ductal morphogenesis, and depletes epithelial stem/progenitor cell reservoirs. Further, Ovol2-deficient epithelial cells undergo EMT in vivo to become non-epithelial cell types, and that Ovol2 directly represses key EMT inducers such as Zeb1 and regulates stem/progenitor cell responsiveness to TGF-beta. We also provide evidence for a suppressive role of Ovol2 in breast cancer progression. Our findings underscore the critical importance of exquisitely regulating epithelial plasticity to balance stemness with epithelial differentiation in development and cancer. We report ChIPseq data illustrating Ovol2 genome-wide targets in mouse mammary epithelial cells, suggesting that Ovol2 regulates a plethora of genes associated with the EMT process. Immunoprecipitated samples from HC11 mouse mammary epithelial cells with antibodies against Ovol2 and control IgG respectively were used for ChIP-seq experiments.