THE DIFFERENTIATION AND LINEAGE DEVELOPMENT OF GOBLET CELLS IN THE MURINE SMALL-INTESTINAL CRYPT - EXPERIMENTAL AND MODELING STUDIES

The objective of this study was to provide a new insight into the origin and lineage development of mucus-producing cells in the small intestinal crypt. For this, new experimental data were obtained from both crypt sections and whole mounts. Model simulation studies were undertaken to investigate which rules are most likely to govern the dynamic cellular development and goblet cell pedigree. We have measured the frequency of mucus-secreting goblet cells (using alcian blue and periodic acid Schiff's stains) at each cell position in the ileal murine crypt. These measurements, made on sections, overestimate the number of goblet cells because of the size and centripetal position of the stained cytoplasm. The correction factor for this overscoring has been measured to be 0.25 by two independent methods. The data suggest that there are about 12 functional goblet cells per crypt many of which retain an ability to divide. We have also determined the labelling index of the crypt goblet cells at each cell position. Spatially, goblet cells exhibit a small degree of clustering in the crypt and show a good mixture with columnar cells. We have adapted our earlier dynamic matrix-based computer simulation model to take into account goblet cell differentiation. The modelling suggested the following conclusions: firstly, goblet cells do not have their own stem cells but share a common stem cell with the columnar cells; secondly, the goblet lineage differentiates from the transit population two to three generations before the end of the lineage; and thirdly, the decision to switch on goblet properties is stochastic at a specific step in the development of columnar cells.