Figure 4

Feedback regulation of gna1 transcription by constitutively activated GNA1. Strains were grown in Mandels-Andreotti medium supplemented with 1% (w/v) lactose, glucose or glycerol as carbon source. Mycelia were precultivated for 24 h (lactose, glycerol) or 17 h (glucose) in darkness (DD) prior to exposure to light (DL; 1,800 lux, 25 μmol photons m^-2 s^-1) for 15, 30, 60, 120 or 240 min. For northern blotting, 20 μg of total RNA were loaded per lane and [α³²P]-radiolabeled PCR fragments of gna1 and 18S rRNA were used as probes.