Chytrids are a poorly studied group of aquatic fungi that ubiquitously inhabit bogs, ponds, and oceans. These fungi are fundamental to the cycling of nutrients, such as through the degradation of pollen, keratin, or through parasitism of organisms such as algae or frogs. Most of what is known about the diversity of chytrids is based on microscopic observations over the last century or from pure cultures established in the last few decades. However, diversity based assessments using the more recently developed DNA-based environmental approaches challenge whether we truly know chytrid diversity, because the species documented in this way typically fail to match species identified using traditional approaches. This project will implement multiple approaches to provide a holistic picture of chytrid diversity and classification that avoids biases of any particular method. Understanding taxonomy of this poorly known group and other fungi is vital for cataloging biodiversity and predicting its environmental impacts. This project will support one Postdoctoral Fellow, a graduate student, and will provide training to undergraduates. Web-based content on the chytrid biology, classification, and will be developed in order to disseminate information to a broader audience. A week-long, hands on workshop on chytrid methods will be held at the University of Michigan Biological Station in order to encourage continued research on this understudied group.
This project leverages an existing and growing historical collection of chytrid cultures and recently developed methods to sequence DNA from single cells. The proposed research includes generating or completing at least 840 ribosomal RNA sequences and 20 genome sequences of chytrids in the Collection of Zoosporic Eufungi at the University of Michigan (CZEUM). It will also employ a single cell approach to phylogenetically characterize uncultured diversity. Specifically, chytrid fungi will be identified in situ in from field sites, photographed, and single cells subjected to genome amplification. From the successfully amplified genomes, 100 diverse samples will be targeted for whole ribosomal RNA operon sequencing using long-read, single molecule DNA sequencing. An additional 20 samples will be used for genome sequencing. A major outcome will be a phylogenetic analysis of the chytrids combining both ribosomal RNA and genome sequencing into a supertree. A final aim of the project is to screen and sequence novel diversity of fungal viruses from the CZEUM collection and to determine the effect of ecology and morphology on viral prevalence. This project will serve as a model for addressing systematics in eukaryotic lineages where culture-based approaches produce an incomplete picture of diversity.
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.
