LTREB: Saurian Malaria: Long-Term Study of Prevalence, Life Histories, and Gametocyte Sex Ratio

University Of Vermont & State Agricultural College, Burlington VT

Investigators

Abstract

0089096 Schall This LTREB project will continue long-term studies on the ecology and evolutionary biology of malaria parasites of lizards. These studies take place at sites in California and the Caribbean. The systems have been under study for the past 9 to 22 years. Three interwoven studies will be pursued that all depend on the long-term data and blood samples obtained during the study. The first study will address parasite prevalence. Prevalence patterns at all four sites do not follow predictions emerging from standard epidemiological models for malaria. These differences are explained by the habitat heterogeneity hypothesis. The second study focuses on life-history traits. Infections in all four lizard species vary significantly in all their life history traits. In this case, two traits will be studied maximum parasitemia and first production of gametocytes. The clonal diversity and stress hypotheses will be tested with additional long-term data. Finally, the project will assess gametocyte sex ratio. The local mate competition hypothesis predicts that gametocyte sex ratios within infections will depend on the genetic diversity of those infections. Two mechanisms related to this hypothesis will be investigated. Together these three foci will expand our understanding of the spatial and temporal dynamics of host-parasite ecology. Results from this project have direct and important implications for understanding the natural history and ecology of emerging infectious diseases that affect animal populations, including humans.