Improved genome assembly of Onygena corvina, a keratin-degrading fungus

Onygena corvina is a non-pathogenic, saprophytic fungus that colonizes feathers, hooves, and hair, and represents a valuable source of keratin-degrading enzymes. The only genome assembly of O. corvina available to date was obtained for the strain CBS 281.48 using Illumina short-read sequencing, yielding a reference genome composed of 521 contigs with a contig N50 of 0.229 Mb. Here, we report an improved O. corvina CBS 281.48 genome assembly generated using a high-quality hybrid approach that combines Illumina short-read and Oxford Nanopore long-read sequencing. The new assembly consists of only 13 contigs totaling 21.8 Mb, with an N50 of 4.4 Mb, and has a completeness of 98.4%. A total of 7,232 protein-coding genes were annotated using an integrative approach that combines de novo predictions, homology-based inferences, and RNA-sequencing–guided evidence. Notably, 158 putative protease-coding genes were identified representing a substantial increase from the 73 predicted proteases in the previous annotation. Our improved genome assembly and associated gene annotations will facilitate comparative genomics, and high-resolution mapping of transcriptomic and proteomic data, to advance research on fungal physiology and fungal abilities to degrade recalcitrant substrates such as keratin.