Comparative genomic study of multiple strains of Coccidioides immitis and posadasii. Coccidioides

Coccidioides immitis and Coccidioides posadassi are soil fungi and the causal agents of coccidioidomycosis or Valley fever, a serious and sometimes fatal disease in otherwise healthy people. C. immitis was placed on a NIAID group II list of priority emerging and re-emerging pathogens. Coccidioides species have also become models for studying the evolutionary biology of pathogenic fungi. Morphologically both species are identical but can be distinguished by numerous DNA polymorphisms. They also differ in growth rate on high-salt media but this phenotype is not diagnostic. C. immitis is dominant in the San Joaquin Valley, California and appears to have the smaller biogeographic distribution of the two species. C.posadassi was previously known as non-California Coccidioides immitis and is widespread throughout most of the endemic regions of the U.S., Mexico and Central and South America. The Coccidioides immitis sequence project targeted multiple Coccidioides strains and was supported by both NHGRI and NIAID through the Broad Institute's Fungal Genome Initiative and its Microbial Sequencing Center (MSC). Strains in the comparative analysis include environmental samples, clinical samples of different virulence levels and samples representing various phylogenetic positions and geographic types. Under the Coccidioides sequence project, the genome of the RS strain was finished and annotated. An additional 11 strains of Coccidioides and EST libraries from both species (C. immitis and C. posadasii) were sequenced. Strains targeted for sequencing were selected by the Coccidioides Genome Resources Consortium (CGRC)