Two unlinked genes for the pyruvate dehydrogenase complex in Aspergillus nidulans

Area of Science:

• Biochemistry
• Molecular Biology
• Mycology

Background:

• The pyruvate dehydrogenase complex is crucial for cellular respiration.
• Understanding its regulation in fungi like Aspergillus nidulans is important for metabolic studies.

Purpose of the Study:

• To investigate the genetic control of the pyruvate dehydrogenase complex in Aspergillus nidulans.
• To identify and characterize genes involved in the complex's function.

Main Methods:

• Selection and analysis of glycolytic mutants.
• Enzyme activity assays for pyruvate dehydrogenase complex.
• Complementation studies using forced heterokaryons and mixed cell-free extracts.
• Genetic mapping of identified mutations.

Main Results:

• Pyruvate dehydrogenase complex activity was similar in wild-type strains grown on sucrose or acetate.
• Eight mutants lacking pyruvate dehydrogenase complex activity were identified.
• Two unlinked genes, pdhA and pdhB, were found to control the complex's function.
• Complementation studies confirmed the roles of pdhA and pdhB.
• pdhA and pdhB were assigned to linkage groups I and V, respectively.

Conclusions:

• The pyruvate dehydrogenase complex in Aspergillus nidulans is controlled by at least two genes, pdhA and pdhB.
• These genes are unlinked and their mutations are recessive.
• This study provides a genetic framework for further investigation of the pyruvate dehydrogenase complex in fungi.