Fig. 3. Expression profiles of the br isoforms. (A) Expression profile of the br isoforms during development of the sixth instar and the seventh instar larvae as determined by RT-PCR. (B) Expression profile of the br isoforms during the development of the hydroprene-treated and the acetone-treated seventh instar larvae as determined by RT-PCR. The hydroprene-treated larvae molt to a supernumerary instar, and the duration of the seventh instar is truncated relative to the acetone-treated final instar larvae. Expression of rps3 is provided to verify equal loading. Cycle numbers for br-Z1, br-Z2, br-Z3, br-Z4, br-Z5 and rps3 are 38, 40, 34, 32, 35 and 37, respectively. D, day.