Fig. 3. Depletion of FRS2 proteins in Frs2^cn prostatic rudiments. (A) Prostates were collected at the indicated times, immunostained with the indicated antibodies, and visualized by confocal microscopy. The prostate epithelial cells were identified with anti-P63 antibody. Expression of FRS2 was assessed with anti-FRS2 antibody. Arrows indicate prostate epithelial cells. Note that FRS2 staining was diminished in Frs2^cn prostates at postnatal day 0.5 (P0.5). (B) The ratio of p63-positive cells in the epithelial compartment at different ages was calculated from three samples. Representative mean±s.d. values of data from triplicate samples are shown. (C,D) Stability of FRS2 proteins as compared with FGFR2 in prostate epithelial cells. TRAMP-C2 cells (1x10⁶) treated with cycloheximide were lysed at the indicated times. The abundance of FRS2 was analyzed by western blot directly from the cell lysates (containing 50 µg protein). FGFR2 in cell lysates (containing 500 µg protein) was pulled down with anti-FGFR2 antibody. The specifically bound fractions were subjected to western analyses (C). The specific bands were quantitated with a densitometer and the data presented as ratios of treated to non-treated cells (D). CHX, cycloheximide; F/F, homozygous Frs2^flox mice; CN, Frs2^cn mice.