FIG. 5.
dBlimp-1 has repressor activity and controls the timing of βFTZ-F1 expression and pupation. (A) Phenotypes of dBlimp-1 RNAi lines. Eight independent UAS-dBlimp-1i lines were mated with the Act-Gal4 line, and prepupae of their progeny were collected and their lethal phases were scored from the prepupal stage to adult. The effect of mutation in the dBlimp-1 gene by P-element insertion (dBlimp-1P14751) was examined for the UAS-dBlimp-1i1 and -5 lines. Numbers in parentheses represent the number of scored animals. Typical examples of arrested animals are shown on the right. (B) Reduction of dBlimp-1 transcript levels in RNAi animals. Expression levels were measured by quantitative real-time RT-PCR using total RNA from prepupae at 2 h APF in the indicated lines. The same template was used to measure the amounts of dBlimp-1 and E75A mRNAs. (C) Premature expression of βFTZ-F1 by RNAi of dBlimp-1. The expression of βFTZ-F1 in dBlimp-1 RNAi (Act5c-Gal4>UAS-dBlimp-1i8) and control (+/UAS-dBlimp-1i8) animals from 4 to 10 h APF was estimated by Western blotting. Anti-α-tubulin antibody was used to confirm the amount of loaded protein in each lane. (D) Delay of βFTZ-F1 expression by induction of dBlimp-1. Prepupae at 5 h APF of the hs-dBlimp-1 line or the host strain were heat shocked at 34°C for 1 h and then reared at 25°C. The expression levels of βFTZ-F1 in two individual prepupae at the indicated times were estimated by Western blotting. Anti-α-tubulin antibody was used to confirm the amount of protein loaded in each lane. (E) Delay of pupation timing by forced induction of dBlimp-1. Prepupae at 5 h APF of the hs-dBlimp-1 line or the host strain were heat shocked at 34°C for 1 h and then reared at 25°C. Numbers of newly pupated animals were counted every hour, and the percentage of pupated animals in each period was plotted. Numbers in parentheses represent the number of scored animals. Four out of 26 animals of the hs-dBlimp-1 line failed to pupate.