Faculty and Research
Heitman Lab Members
312 CARL Building
Box 3546 DUMC
Durham, N.C. 27710
I am a fourth year graduate student from the University Program in Genetic and Genomics. I entered Duke through the CMB program in 2010 through the Cell and Molecular Biology program. After my undergraduate work at the University of Maryland, I spent a year as a post-baccalaureate fellow at the National Cancer Institute in Bethesda.
Fungal pathogens, like Cryptococcus neoformans, typically cause disease in immunocompromised patients. These patients normally include AIDS patients as well as anyone undergoing immunosuppressive therapy, such as transplant recipients. A notable exception to this general principle is the closely related pathogen Cryptococcus gattii which shows a different host tendency than C. neoformans. Two of the C. gattii subtypes, VGIII and VGIV, retain the proclivity for infecting immunocompromised hosts, but the other two, VGI and VGII, tend to infect otherwise healthy individuals. The VGII subtype is responsible for an ongoing and expanding outbreak, originating from the Vancouver Island area of the Pacific Northwest.
Genomes for prototypical strains of VGI and VGII have both been sequenced recently and my research will explore insights gained from the comparative genomic analysis this has allowed. In particular, the outbreak strains of VGII have been found to lack most of the canonical components of the RNAi pathway. RNAi loss is a phenomenon that is broadly present throughout fungi, with the most famous example being S. cerevisiae. Studying C. gattii may allow us to understand the importance, or lack thereof, of RNAi to a pathogen expanding into a new and previously inhospitable environment.
In addition, I am interested in the development of the C. gattii outbreak in the Pacific Northwest. The recent availability of cheap, high-throughput genome sequencing has allowed us to begin asking questions about this outbreak in a different way. I am currently working to develop and use new genomic approaches to better understand how these pathogenic fungi arrived in the Pacific Northwest, and what evolutionary forces might be driving the development of this outbreak.
Billmyre RB, Calo S, Feretzaki M, Wang X, Heitman J (2013) RNAi function, diversity, and loss in the fungal kingdom. Chromosome Research 21(6-7).
Calo S, Billmyre RB, Heitman J (2013) Generators of phenotypic diversity in the evolution of pathogenic microorganisms. PLOS Pathogens 9(3): e1003181. doi:10.1371/journal.ppat.1003181
Springer DJ, Phadke S, Billmyre RB, Heitman J (2012) Cryptococcus gattii, no longer an accidental pathogen? Current Fungal Infection Reports 6(4).