A chromosomal-level reference genome of the widely utilized Coccidioides posadasii laboratory strain "Silveira".

Coccidioidomycosis is a common fungal disease that is endemic to arid and semi-arid regions of both American continents. Coccidioides immitis and Coccidioides posadasii are the etiological agents of the disease, also known as Valley Fever. For several decades, the C. posadasii strain Silveira has been used widely in vaccine studies, is the source strain for production of diagnostic antigens, and is a widely used experimental strain for functional studies. In 2009, the genome was sequenced using Sanger sequencing technology, and a draft assembly and annotation were made available. In this study, the genome of the Silveira strain was sequenced using single molecule real-time sequencing PacBio technology, assembled into chromosomal-level contigs, genotyped, and the genome was reannotated using sophisticated and curated in silico tools. This high-quality genome sequencing effort has improved our understanding of chromosomal structure, gene set annotation, and lays the groundwork for identification of structural variants (e.g. transversions, translocations, and copy number variants), assessment of gene gain and loss, and comparison of transposable elements in future phylogenetic and population genomics studies.

Genomic characterization of Parengyodontium americanum sp. nov.

Modern genome analysis and phylogenomic methods have increased the number of fungal species, as well as enhanced appreciation of the degree of diversity within the fungal kingdom. In this context, we describe a new Parengyodontium species, P. americanum, which is phylogenetically related to the opportunistic human fungal pathogen P. album. Five unusual fungal isolates were recovered from five unique and confirmed coccidioidomycosis patients, and these isolates were subsequently submitted to detailed molecular and morphological identification procedures to determine identity. Molecular and morphological diagnostic analyses showed that the isolates belong to the Cordycipitaceae. Subsequently, three representative genomes were sequenced and annotated, and a new species, P. americanum, was identified. Using various genomic analyses, gene family expansions related to novel compounds and potential for ability to grow in diverse habitats are predicted. A general description of the genomic composition of this newly described species and comparison of genome content with Beauveria bassiana, Isaria fumosorosea and Cordyceps militaris shows a shared core genome of 6371 genes, and 148 genes that appear to be specific for P. americanum. This work provides the framework for future investigations of this interesting fungal species.