title: Mucous cells and cell migration in the mouse duodenal epithelium.
abstract: The distribution of mucous cells in the mouse duodenum was used to determine whether or not intestinal epithelial cells move as a sheet during their migration from crypts to villi. The experiments took advantage of the probable symmetry of mucous-cell divisions (symmetry in the sense that each mucous-cell division produces two mucous cells). Since approximately 50% of newly formed mucous cells are derived from mucous-cell divisions, at least 50% of newly formed mucous cells in the crypt should be found in mucous-cell pairs. It follows that if the epithelium moves as a firmly interconnected sheet, at least 50% of mucous cells found in the villus should also be in pairs. On the other hand, if a significant amount of cell mixing occurs during migration, the pairing tendency of mucous cells would be lost. Mucous-cell pairing was determined by two independent methods: 1) direct observation of mucous-cell pairs and 2) the application of Poisson statistics to the mucous-cell distribution to determine a "pairing tendency." We found that in the crypt at least 75-80% of newly formed mucous cells occur in pairs, while in all regions of the villus (base, middle, and top) mucous cells are distributed randomly. These results strongly indicate the existence of a significant amount of cell mixing in the epithelium at some point between the site of mucous-cell formation in the crypts and the villus base. Since the mucous-cell population was randomly distributed in all regions of the villus we were unable to determine whether or not additional cell mixing occurs in the villus epithelium.
mesh_terms: D000818:Animals; D002452:Cell Count; D002465:Cell Movement; D004386:Duodenum / Q000033:anatomy & histology / Q000166:cytology*; D004847:Epithelial Cells; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009092:Mucous Membrane / Q000166:cytology