Fig. 2From: Development of an auto-inducible expression system by nitrogen sources switching based on the nitrogen catabolite repression regulationCharacterization comparison of the PniaD and PniiA. Transcription level of niiA gene (a) and niaD gene (b) in A. nidulans. (c). The activity of GUS controlled by PniaD and PniiA. The time of mycelia transfer from 10 mM proline to 10 mM NO3− or 10 mM NH4+ was 0 minBack to article page