Spatial expression of Drosophila Glutathione S-transferase-D1 in the alimentary canal is regulated by the overlying visceral mesoderm

Regional gene expression within Drosophila gut epithelium is regulated by t he homeotic genes expressed in the overlying visceral mesoderm. Here it is reported that Glutathione S-transferase-D1 (Gst-D1) had three distinctive e xpression domains in the gut epithelia: the inner epithelium of the provent riculus, the anterior border of the hindgut epithelium, and the midgut epit helium. Gst-D1 expression in the midgut epithelium became restricted to the region that later formed the third midgut constriction. This spatial restr iction within the midgut epithelium required abdominal-A activity in the ov erlying visceral mesoderm, suggesting that Gst-D1 will be a useful marker t o analyze the mechanism of gene regulation across the mesoderm and endoderm .