Comparative genomic analyses of chronic wasting disease-associated polymorphisms in cervids from novel, isolated clusters in North America
Category: Research Poster
Author(s): Sophia Serwold, Hannah Bodrogi, Zoe Atkinson, Joseph DeFranco, Glenn Telling
Presenter(s): Sophia Serwold
Mentors(s): Joseph DeFranco
Chronic wasting disease (CWD) is a fatal neurological disease affecting elk, deer, and other cervids. Genetic components play a role in the susceptibility and protection of these animals and modify the properties of CWD. First identified in Colorado in the 1960s, CWD later spread into the Prairie Provinces of Canada and the Midwest United States. These large clusters of CWD were identified to have a similar prevalence of disease-associated polymorphisms. Within the last seven years, there have been new geographically isolated clusters across North America, including in the state of Idaho and four Mid-Atlantic states. The genetic composition of the diseased cervids in these clusters is unknown. We collected presumptive CWD-positive lymph node samples and confirmed disease using real-time quaking induced conversion. We extracted genomic DNA, amplified the PrP open reading frame by polymerase chain reaction (PCR), and used nanopore sequencing to determine the PRNP sequence of the CWD-positive isolates. We found that these polymorphisms were equivalent to the previously identified sequences in other clusters. These data suggest that these novel clusters are due to horizontal transmission to new regions, not a distinct strain of CWD. We also used genomic DNA to assess the prevalence of female and male cervids that were determined to be positive for CWD and discovered a higher percentage of male CWD-positive cases. These results improve our understanding of the genetic factors contributing to CWD cases in North America.