The role of the evolutionary conserved transcription factor PRO44 in multicellular development in fungi

• Applicant: Privatdozentin Dr. Minou Nowrousian
• Subject Area: Evolution and Systematics of Plants and Fungi ; Plant Genetics and Genomics ; Plant Cell and Developmental Biology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 545079769

The aim of the project is to analyze the role of the evolutionary conserved transcription factor PRO44 in the regulation of the spatio-temporal control of development during fungal fruiting body development. In previous analyses of several research groups it was shown that the transcription factor PRO44 is essential for this process in several ascomycetes and one basidiomycete. Fruiting bodies of asco- and basidiomycetes are complex multicellular structures that serve the production and dispersal of sexual spores. In the ascomycete Sordaria macrospora, deletion of the pro44 gene does not only lead to a block in fruiting body development at an early stage, but also to mislocalization of the fruiting bodies within the mycelium, because the mutant forms fruiting bodies within the agar medium, whereas the wild type only forms fruiting bodies at the agar surface. However, it has not yet been clarified if the DNA binding domain and/or other conserved regions of the PRO44 protein are essential for the functions of PRO44. Therefore, one aim of this project is the analysis of different mutations in the gene with respect to their ability to complement the developmental phenotypes of the pro44 mutant. In previous projects, we could show that transcription of the pro44 gene in young fruiting bodies is upregulated compared to vegetative mycelium, and that the PRO44 protein is present mostly in the outer layers of young fruiting bodies. Therefore, one hypothesis is that PRO44 regulates the transcriptome of developing fruiting bodies and thereby initiates downstream developmental processes towards a mature fruiting body. Previous transcriptomics studies were conducted with young fruiting bodies, but fruiting bodies consist of several different cell types, therefore a bulk transcriptomics approach can give only little information about the precise role of PRO44 in developmental processes in the fruiting body. Therefore, one aim of the project is to establish single cell transcriptomics for S. macrospora to analyze transcriptomes of different cell types from fruiting bodies. Single cell transcriptomics will be used to analyze the wild type and the pro44 mutant to identify differences in gene expression in different cell types depending on the presence of pro44. The PRO44 protein from S. macrospora forms homodimers, whereas the corresponding ortholog from the ascomycete Neurospora crassa was shown to interact with another transcription factor, FF-7. Since it is possible that the role of PRO44 in different developmental processes like the spatio-temporal placing of fruiting body precursors and the subsequent maturation of the fruiting bodies is mediated through interactions with different interaction partners, the third aim of the project is the identification of (additional) interaction partners.

• DFG Programme: Research Grants