BioProject

In the adult mouse, distinct morphological and transcriptional differences separate stomach from intestinal epithelium. More...

In the adult mouse, distinct morphological and transcriptional differences separate stomach from intestinal epithelium. Remarkably, the epithelial boundary between these two organs is literally one cell thick. This discrete junction is established suddenly and precisely at embryonic day (E) 16.5, by sharpening a previously diffuse intermediate zone. In the present study, we define the dynamic transcriptome of stomach, pylorus and intestinal tissues between E14.5 and E16.5. We show that establishment of this boundary is concomitant with the induction of over a thousand genes in intestinal epithelium, and these gene products provide intestinal character. Hence, we call this process intestinalization. We identify specific transcription factors (Hnf4g, Creb3l3 and Tcfec) and examine signaling pathways (Hedgehog and Wnt) that may play a role in this process. Finally, we define a unique expression domain at the pylorus itself and detect novel pylorus-specific patterns for the transcription factor Gata3 and the secreted protein nephrocan. Overall design: Stomach, pylorus and duodenum tissue from E14.5 and E16.5 mouse embryos were collected for RNA extraction and hybridization on Affymetrix microarrays. We sought to study the gene expression profiles and identify genes and pathways enriched in these three tissues at two important developmental times. Less...