Home • Calocera cornea v1.0
Photo of Calocera cornea v1.0
Credit: Michael Wood/Mykoweb.com

This genome was sequenced as a part of the large-scale multi-genome JGI CSP Saprotrophic Agaricomycotina Project (SAP), which focuses on the diversity and evolution of decay mechanisms, organismal phylogenetic relationships, and developmental evolution. A large collaborative effort led by PI of this project, David Hibbett (Clark University) aims for master publication(s) of the SAP data analysis. Researchers who wish to publish analyses using data from unpublished SAP genomes are respectfully required to contact the PI and JGI to avoid potential conflicts on data use and coordinate other publications with the SAP master paper(s).

Calocera cornea is a jelly fungus, which is a descriptive term for a polyphyletic group of fungi with gelatinous, translucent fruiting bodies. This species occurs on decaying conifer wood. Calocera cornea is a member of the Dacrymycetes, which is the sister group of the Agaricomycetes (the group of Fungi that incudes the majority of mushroom-forming and wood decay species). Jelly fungi also occur in the Tremellomycetes, which is the sister group to the clade containing Dacrymycetes and Agaricomycetes, and in the Agaricomycetes itself. Calocera cornea is the third jelly fungus to be sequenced by the JGI, the others being Tremella mesenterica (Tremellomycetes), Auricularia delicata (Agaricomycetes), and Dacryopinax sp. (Dacrymycetes). A third species of Dacrymycetes, Calocera viscosa, will also be sequenced. This species is part of the Saprotrophic Agaricomycotina Project (SAP), which focuses on the evolution of decay capabilities in mushroom forming fungi (Agaricomycotina). A major motivation for targeting jelly fungi in the SAP, and the Dacrymycetes in particular, is that they may provide insight into the early origins of the white rot decay mode in the Agaricomycetes. An analysis of 31 fungal genomes by Floudas et al. (Science 336:1715-1719, 2012) suggested that the ancestor of the Agaricomycetes was a white rot fungus, meaning that it had the capacity to degrade the recalcitrant plant cell wall polymer lignin. The Floudas et al. study suggested that fungal class II peroxidases, which are enzymes that play a critical role in lignin decomposition, began to diversify early in the evolution of the Agaricomycetes, perhaps even before the divergence of Agaricomycetes and Dacrymycetes (based on gene tree/species tree reconciliation analyses). The Dacryopinax genome is devoid of genes encoding class II peroxidases, but there are some species of Dacrymycetes that are reported to produce a white rot, including Calocera viscosa. In contrast, Dacryopinax and C. cornea produce a brown rot, in which lignin is not appreciably degraded. By targeting this suite of Dacrymycetes, it should be possible to rigorously address the origin of class II peroxidases and white rot chemistry.

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