Figure 1.

Complex control of wc-1 transcription. (A) Entrainment of circadian conidiation depends on the wc-1 promoter. Race tubes, inoculated with the indicated strains, were exposed to 1 h:23 h light:dark cycles at 25°C. Averaged conidial densities (n=3) were plotted versus time. (B) Resetting of the clock by light is altered in the Δwc-1, qa-wc-1 (dotted grey line) strain compared with wc-1⁺ (black line). Race tubes were exposed to 20 min light pulses at the indicated time in constant darkness (DD). The phase shift of conidial bands (compared with control strains kept in DD) was blotted versus time when the light pulse was given. Black and dotted bars at the bottom indicate subjective night and day, respectively. (C) The transcription of wc-1 is initiated at various sites. The wc-1 gene is schematically outlined. The positions of four amplicons generated by RNA ligase-mediated rapid amplification of complementary DNA ends are indicated above. The putative promoters P_dist, P_prox and P_int are indicated by arrows.