Control of mating and development in Ustilago maydis

Area of Science:

• Molecular Biology
• Mycology
• Genetics

Background:

• The fungus Ustilago maydis utilizes two mating-type loci for partner recognition.
• Extracellular recognition occurs via a pheromone system, while intracellular recognition is allele-specific.

Purpose of the Study:

• To elucidate the molecular mechanism of intracellular mating type recognition in Ustilago maydis.
• To investigate the role of homeodomain proteins and their interactions in determining mating compatibility.

Main Methods:

• Analysis of homeodomain protein interactions encoded by different mating-type alleles.
• Investigating pairwise combinations of proteins to determine recognition specificity.

Main Results:

• Homeodomain proteins from different alleles form active heterodimers.
• Proteins encoded by the same allele do not interact, suggesting a specific recognition code.
• This interaction pattern governs intracellular recognition after cell fusion.

Conclusions:

• The ability of Ustilago maydis to distinguish mating partners is mediated by allele-specific protein-protein interactions.
• A code for protein recognition exists, based on the formation of heterodimers between homeodomain proteins from different mating-type alleles.