Postdoctoral Fellowship: PRFB: The role of genotype and environment in shaping individual nuclear contributions to transcription in dikaryotic fungi

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2025. The fellowship supports research and training of the fellow that will contribute to biology in innovative ways. Mushroom-forming fungi are an understudied, but ecologically and economically important group of organisms.

They spend most of their lives as dikaryons, with two genetically different nuclei in every cell. However, it is unclear how cells with two nuclei coordinate gene expression, which is essential for cells to function. These nuclei may contribute equally to gene expression, or one may contribute more than the other.

This project will measure the contribution of individual nuclei in a dikaryotic cell to gene expression. The findings from this project will contribute to our understanding of how mushroom-forming fungi regulate growth and development, as well as respond to their environment.

This project will quantify the relative contribution of different nuclear types to transcription under (I) different genetic backgrounds (nuclear and mitochondrial) and (II) abiotic stress to investigate how genotype x genotype and environment x genotype interactions shape gene expression in dikaryotic (two haploid nuclei/cell) fungi. Haploid (monokaryotic) isolates of the ectomycorrhizal fungus Suillus subaureus will be isolated from spores and then paired to form different combinations of nuclear and mitochondrial genotypes.

RNA from each genotypic combination will be extracted and sequenced, and reads will then be mapped to their nucleus of origin to quantify the relative contributions of each nuclear type to transcription. This project will test both the effect of nuclear and mitochondrial genotype, as well as environmental stressors, on the relative expression levels of individual nuclear types.

This research will further scientific understanding of how individual genomes (nuclear and mitochondrial) contribute to gene expression in dikaryotic fungal cells, as well as in diploid and polyploid cells more broadly. To engage with students, the fellow will create undergraduate teaching modules on fungal reproduction. Additionally, the fellow will work with scientific societies to develop guidelines for giving accessible and understandable presentations at conferences.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.