Organogenesis of the Caenorhabditis elegans intestine

The intestine of Caenorhabditis elegans is an epithelial tube consisting of only 20 cells and is derived clonally from a single embryonic blastomere c alled E. We describe the cellular events that shape the intestine. These ev ents include cytoplasmic polarization of cells in the intestinal primordium , the intercalation of specific sets of cells, the generation of an extrace llular cavity within the primordium, and adherens junction formation. The p olarization of the intestinal primordium is associated with the generation of an asymmetric microtubule cytoskeleton, and microtubule function plays a role in subsequent cell polarity. We show that an isolated E blastomere is capable of generating polarized intestinal cells, indicating that some of the major events in intestinal organogenesis do not depend upon interaction s with surrounding tissues. We compare and contrast intestinal organogenesi s with some of the basic steps in development of a second epithelial organ, the pharynx, and suggest how these differences lead to organs with distinc t shapes. (C) 1999 Academic Press.