Fig. 1. slmb shows a dynamic expression pattern during egg chamber development. Ovaries from females carrying the slmb⁰⁰²⁹⁵ enhancer trap were analyzed by X-gal staining or by anti-ß-galactosidase (anti-ß-gal) immunofluorescence. (A) In the ovariole, nurse cells stain positive for X-gal throughout oogenesis (arrows). X-gal signal in FC surrounding the oocyte appears at mid-oogenesis (arrowhead). (B,C) In the germarium, expression of ß-gal (green) is restricted to the germline and is excluded from FC that express Fasciclin 3 (red). (D) Expression of ß-gal cannot be detected in FC at stage 8 (arrowhead) and starts at stage 9 (E, arrowhead). (F) At oogenesis stage 10, strong expression of the enhancer trap occurs in a scattered pattern in the follicular epithelium (arrows). (G) At stage 11, expression becomes stronger in two patches of FC that will form the dorsal appendages (arrows).