Flies are cryo-sectioned, fixed for 20 minutes in 1% glutaraldehyde in phosphate-buffered saline (1x PBS), and reacted with standard X-gal solution (5-bromo-4-chloro-3-indolyl-§-D-galactopyranoside)(Ashburner, 1989) at 37ūC. All sections were processed and stopped at the same time. The reactions are terminated by rinsing twice with 1xPBS before mounting in 70% glycerol in 1x PBS. The reaction was monitored and the time depended on the line and the age that had the strongest staining before reaching saturation.

Detailed protocol