Comparative genomic study of Coccidioides species and their relatives in the Onygenales. Onygenales

Coccidioides immitis and Coccidioides posadassi are the causal agents of coccidioidomycosis or Valley fever. Morphologically both are identical but can be distinguished by numerous DNA polymorphisms. Both species belong to the order Onygenales which contain members that tend to associate with animals. Considering the following evolutionary relationships, the comparative genomic study investigated the hypothesis that Coccicioides have recently acquired its pathogenic phenotype. Onygenales relatives that recently diverged relative to the Coccidioides clade such as Uncinocarpus, Gymnoascus, and Crysosporium species have not been reported to cause disease but the more distantly related, Ajellomyces capsulatum, are known to be a mamalian pathogen.