A Comparative Genomics Approach to Cocciodiomycosis Risk in Przewalski’s Horses

Cocciodiomycosis is a fungal disease (valley fever) that is an endemic disease factor in regions of the central valley of California and Southern California. One of the first gorillas brought to the San Diego Zoo died of cocciodiomycosis. This disease has emerged as a particularly problematic element in the propagation of Przewalski’s horses at the Wild Animal Park.

An initial study, published by CRES Pathology Fellow Dr. Karen Terio, examined the impact of this disease and on our collections. Moreover, her study began an evaluation of the sensitivity of the Przewalski’s horse immune system to this pathogen that would be novel for a central Asian species. This project will continue to investigate immune system function, and the genes that underlie this function, in a collaborative study potentially involving the University of Illinois (Dr. Terio’s current institutional affiliation) and the Baker Institute of the New York State College of Veterinary Medicine at Cornell. A whole-genome DNA sequence from a domestic horse (specially bred to facilitate DNA sequence evaluation of immune system genes) is about to be sequenced at the Broad Institute/MIT. The availability of the genome sequence of a domestic horse will directly facilitate the development of primers for PCR analysis of the Przewalski’s horse's immune system. Data from comparative sequencing of the Przewalski’s horse immune system genes can be utilized to analyze genetic susceptibility in extension of previous work.