Dung-Loving Bird's Nest Fungus (Cyathus stercoreus) on bison dung. [Image credit: User Kiloueka, via Wikimedia Commons under CC0 1.0 Universal Public Domain Dedication]

In the “1KFG: Deep Sequencing of Ecologically-relevant Dikarya” project (CSP1974), we are sequencing keystone lineages of plant-interacting fungi and saprophytic fungi that are of special ecological importance for understanding terrestrial ecosystems. In addition, comparative genome analysis with saprotrophic, mycorrhizal and pathogenic fungi will provide new insights into the specific and conserved adaptations associated with each fungal lifestyle.

Cyathus stercoreus NK-82

Cyathus (family Nidulariaceae, class Agaricomycetes) is the most species-rich genus of bird’s nest fungi. Cyathus species are saprotrophic fungi that grow on woody debris and mulch. Cyathus species are phylogenetically distant from other genera of bird’s nest fungi and form a well-supported monophyletic clade (Kraisitudomsook et al. 2021). Morphologically, Cyathus species have cupulate peridia (an outer covering of the fruiting body), epiphragms (a lid on the peridium that covers the peridioles when young), and funiculi (specialized cords that attach the peridioles to the peridium) (Brodie 1975). They also produce relatively large peridioles (egg-like spore cases which contain basidiospores and basidia) that are usually dark (black, dark grey, or dark brown).

Cyathus stercoreus is the second species of the striatum group (Zhao et al. 2007) to have its genome sequenced. Cyathus stercoreus is recognized by the large basidiospores and matted hairs covering the peridia. The genome strain NK-82 was isolated from of a fruiting body of C. stercoreus that grew on mulch in Riverside, California (USA). This species is particularly interesting because, unlike other Cyathus species, C. stercoreus grows well on herbivore dung (Brodie 1975). Moreover, researchers were able to induce fruiting-body production of C. stercoreus in axenic culture (Webster and Weber 1997). Because of its ability to grow on dung and fruit in vitro, the genome of C. stercoreus will greatly improve our understanding of the genetics behind bird’s nest fungi mating genetics and evolution. Lastly, we would be able to compare the enzymatic signatures of dung-inhabiting species with other wood-decay fungi.

Researchers who wish to publish analyses using data from unpublished CSP genomes are respectfully required to contact the PI and JGI to avoid potential conflicts on data use and coordinate other publications with the CSP master paper(s).