Education

• Ph.D. Genetics, University of Melbourne, 1998
• B.Sc. (Hons) Genetics, University of Adelaide, 1991
• B.Sc. Genetics, Biochemistry, University of Adelaide, 1990

Postdoctoral experience

• Department of Genetics, University of Melbourne, 1998-2003
• Department of Genetics, University of Adelaide, 1998
• Biotechnology Laboratory and Department of Botany, University of British Columbia, 1996-1998

Other Experience

• Lecturer, Department of Genetics, University of Melbourne, 2003-2008
• Research Associate (Honorary), Department of Genetics, University of Melbourne, 2008-present

Research

Research in Richard Todd’s Fungal Genetics and Genomics Lab aims to understand the molecular mechanisms regulating fungal metabolic gene expression.

Our key questions are:

• How do transcription factors (proteins that control gene expression) regulate nitrogen utilization in fungi?
• How is the information encoded by nutrient metabolism genes used differentially, depending on nutrient quality and availability, to coordinate nutrient acquisition?
• What are the signaling mechanisms underlying metabolic gene regulation?

We use the filamentous fungus Aspergillus nidulans, an important genetic model for both harmful and beneficial molds, to study gene regulation. Aspergillus species are highly prevalent in nature and include important industrial species and pathogens. Industrial Aspergilli are used for production of foods (e.g. soy sauce, sake, miso), enzymes (e.g. amylases, xylanases, oxidases and proteases used for dough improvement in the baking industry), and metabolites (e.g. citric acid, lovastatin).

Aspergillus species include important plant pathogens, which make carcinogenic aflatoxin that can contaminate food and feed, as well as Aspergillosis-causing pathogens of coral, birds, animals, and humans. Aspergillus nidulans is usually not pathogenic, but lives in soils and degrades a wide range of complex biological matter, using enzymes to break down these nutrients and synthesize new products.

Nitrogen nutrient availability and quality is important for fungal pathogens as they adapt to the host environment, and for industrial fungi as they break down nutrients via metabolism for biosynthesis of products of commercial value.

Our research focuses on important transcription factors involved in nitrogen regulation in Aspergillus nidulans, including AreA, TamA, NmrA, and LeuB. We aim to understand how the activity of these transcription factors is regulated to control coordinated expression of their target genes. We use a combination of genetics, molecular biology, cell biology, genomics, and biochemistry to analyze gene function. We study the molecular mechanisms underlying the following processes:

• Regulation of nitrogen metabolic gene expression and nitrogen utilization.
• Regulation of transcription factor activity.
• Control of import and export of transcription factors into the cell nucleus.
• DNA binding and DNA binding-independent functions of transcription factors.
• Leucine biosynthesis.
• Secondary metabolism.

What is Aspergillus nidulans?

• Aspergillus nidulans is a filamentous fungus, a mold, a microbe, and a eukaryote.
• Aspergillus species can be found everywhere.
• Aspergillus nidulans generally lives in soil.

Why use Aspergillus nidulans as a model for the Aspergilli and other pathogenic fungi?

• Excellent genetics: Aspergillus nidulans is one of the best systems for studying fungi due to ~70 years of genetic analysis and the development of molecular genetics tools for gene manipulation that often are not available or as easy in other fungi.
• Conserved genes: Many of the genes and molecular mechanisms underlying common processes are conserved between Aspergillus nidulans and other fungi, including fungal pathogens.