Grant Abstracts:
NIH Grant #1R01GM60766-01
"Disease on New Hosts..."

The issues: Much of our research focuses on the anther-smut disease (caused by the fungus Microbotryum violaceum) that occurs in many species of Silene and other members of the plant family Caryophyllaceae. The disease is pollinator transmitted, sterilizing,and serves as a model system for studying sexually transmitted diseases in natural populations. We study its long-term dynamics, spatial ecology, and genetics. We are using this disease to model the factors determining host shifts and the emergence of new diseases.

Research:
Long-term disease dynamics -- We are now in our seventeenth year of censusing the disease in the region of Mountain Lake Biological Station in several hundred natural populations. The data on these populations is being used to examine the role of regional (metapopulation) processes in disease dynamics.

Disease on new hosts: Microbotryum as a model system -- A pressing issue in the present day world is the emergence of new diseases. While we have some answers about the emergence of specific diseases such as hantavirus and AIDS, there have been almost no general study of this phenomenon in nature. Our studies consist of monitoring disease emergence on a new host, Silene vulgaris, from the more commonly diseased Silene latifolia. We carry out experimental studies to quantify cross-species transmission and to examine evolutionary changes in the host and pathogen. We are constructing species level phylogenies of both the host and pathogen to develop more rigorous methods for predicting disease emergence.

Sexually transmitted diseases in animal populations -- We have continued to investigate the biology of sexually transmitted diseases in natural populations. Using phylogenetically based comparative methods, we are investigating the occurrence of sexually transmitted diseases in the primates and other mammals in relation to their social systems, mating systems, and habitat use. This work is being carried out in collaboration with colleagues in several universities as part of a working group on "disease in mammalian social systems."