Genomics in Coccidioides: insights into evolution, ecology, and pathogenesis.

Coccidioides immitis and C. posadasii, the causative agents of the mammalian disease coccidioidomycosis, are dimorphic fungal pathogens distributed throughout desert-like environments in North and South America. Coccidioides spp. are members of the Onygenales, a diverse group of pathogenic and nonpathogenic fungi. Recently, full genomes have been published for Coccidioides and a number of other Onygenales species. Phylogenomic comparisons and additional studies in Coccidioides population genomics and gene expression have shed light on the ecology and pathogenesis of Coccidioides and the other medically important species in this clade. Observed patterns of gene family expansion/contraction and evidence of gene flow have provided insight to the evolution of Coccidioides and greatly broadened our understanding of the diversity and sources of genetic variation found in fungi. In the future, expansion of the number of sequenced isolates from all populations will allow deeper insight into the evolutionary processes that have shaped this unique human pathogen. In addition, deep sequencing of isolates from a single Coccidioides population and pairing of those data with phenotype information on growth and pathogenicity for genome-wide association analysis will allow researchers to find genes responsible for any phenotype, virulence included, that shows variation in the population.