DIFFERENTIATION AND SELF-RENEWAL IN THE MOUSE GASTROINTESTINAL EPITHELIUM

The mouse gut epithelium represents a dynamic, geographically well org anized, developmental system for examining serf-renewal and differenti ation. Reagents are now available for identifying the molecular mechan isms that regulate cell fate in the gut, the migration-associated diff erentiation programs of its component cell lineages, and its axial pat terning. Considerable attention needs to be paid to two variables when studying gastrointestinal epithelial cell biology: space and time. Th is has necessitated the use of normal, chimeric, and transgenic animal s as experimental models.