flbD encodes a Myb-like DNA-binding protein that coordinates initiation of Aspergillus nidulans conidiophore development.

摘要: The timing of asexual fruiting body formation during Aspergillus nidulans colony development is precisely regulated so that conidiophores are typically produced 1-2 mm behind the growing edge colony. Mutations in any four A. genes, flbB, flbC, flbD, or flbE, result colonies delayed at least 24 hr their ability to initiate conidiophore resulting fluffy with forming center, 12-15 edge. requirement for each these genes determining developmental initiation precedes transcriptional activation primary regulatory gene brlA, indicating a possible role developmentally brlA expression. wild-type flbD was isolated and shown encode an approximately 1.6-kb mRNA present throughout life cycle. deduced FlbD protein sequence predicts 314-amino-acid polypeptide significant identity its amino terminus DNA-binding domain Myb family transcription factors probably functions as sequence-specific activator. Although does not normally occur submerged culture, forced overexpression hyphae caused inappropriate expression resulted production complex all distinct cell types observed including viable spores. This activate conidiation requires flbA (another early regulator) but require flbC flbE. We propose normal by activating other required (such brlA) activity controlled post-transcriptionally unknown mechanism.