Program Book - 27th Fungal Genetics Conference

CONCURRENT SESSION ABSTRACTSComparing comparative “omics” in Coccidioides spp. Emily A. Whiston, John W. Taylor. Plant & Microbial Biology, U.C. Berkeley, Berkeley, CA.The mammalian pathogens Coccidioides immitis and C. posadasii are the only dimorphic fungal pathogens that form spherules in the host. Furthermore,all of Coccidioides’ closest known relatives are non-pathogenic. In this project, we are interested in genome changes between the Coccidioides lineage andits relatives, and how these changes compare to recently published comparative and population genomics, and transcriptomics studies in Coccidioides.Coccidioides and its closest sequenced relative, Uncinocarpus reesii, are estimated to have diverged 75-80 million years ago. Here, we have sequenced thegenomes of four species more closely related to Coccidioides than U. reesii: Byssoonygena ceratinophila, Chrysosporium queenslandicum, Amauroascusniger and A. mutatus. For each of these four species, we prepared genomic DNA Illumina sequencing libraries; the resulting genome assemblies rangedfrom 23-34Mb, with N50 of 90kb-205kb. Predicted genes were confirmed by RNAseq; the total number of genes ranged from 8,179-9,184. We assessedindividual gene gain/loss, and gene family expansion/contraction in Coccioides using these new genomes and other recently published genomes from theOnygenales order, including the yeast-forming dimorphic pathogens Histoplasma and Paracoccidioides, and the dermatophytes Microsporum andTrichopyton. We have compared these results to genes identified in recently published Coccidioides “omics” studies that show evidence of positiveselection, introgression and/or differential expression.27th Fungal Genetics Conference | 77