POLE CELL-MIGRATION THROUGH THE GUT WALL OF THE DROSOPHILA EMBRYO - ANALYSIS OF CELL-INTERACTIONS

Early in development the precursors of germ cells in Drosophila migrat e at the posterior pole of the embryo and translocate to the bottom of the developing posterior midgut primordium. At the end of germ band e longation the pole cells cross the gut wall to enter in association wi th the gonadal mesoderm. We used laser scanning confocal microscopy on whole-mount Rh-phalloidin-stained embryos and transmission electron m icroscopy to investigate how pole cells cross the epithelial wall of t he posterior midgut primordium. Our results suggest that pole cells le ave the midgut sac by traveling through the intercellular spaces of th e epithelium. During this process the epithelial cells at the bottom o f the posterior midgut primordium are greatly deformed, but their junc tional complexes do not completely release, avoiding breaks in the epi thelial wall. (C) 1995 Academic Press, Inc.