Select a year 2001 2002 2003    Select a researcher Alan G. Barbour, M.D. William Bishai, M.D., Ph.D. Martin J. Blaser, M.D. John C. Boothroyd, Ph.D. Jon Clardy, Ph.D. Peter Cresswell, Ph.D. Roy Curtiss, III, Ph.D. Ronald W. Davis, Ph.D. Jack E. Dixon, Ph.D. Stanley Falkow, Ph.D. Gerald R. Fink, Ph.D. Richard A. Flavell, Ph.D. Lee Gehrke, Ph.D. Laurie H. Glimcher, M.D. Jeffrey I Gordon, M.D. Daniel L. Hartl, Ph.D. William R. Jacobs, Jr., Ph.D. Keith A. Joiner, M.D., co-PI Karla Kirkegaard, Ph.D. Roberto G. Kolter, Ph.D. W. Ian Lipkin, M.D. Richard M. Locksley, M.D. Carl Nathan, M.D. Peter Palese, Ph.D. Pradipsinh K. Rathod, Ph.D. David A. Relman, M.D. Charles M. Rice, Ph.D. Alexander Rich, M.D. Lee W. Riley, M.D. David S. Roos, Ph.D. Abigail A. Salyers, Ph.D. Gary K. Schoolnik, M.D. Iwona Stroynowski, Ph.D. Ronald P. Taylor, Ph.D. Elisabetta Ullu, Ph.D. John Waitumbi, D.V.M., Ph.D Select a project A Gnotobiotic Zebrafish Model for Analyzing Symbiotic Host...Antiviral Effects of Interferon-Inducible Cytosolic ProteinsArming the Immune System against Pathogens with Selective ...Bacterial Pathogen Families that Function in Both the Anim...Cellular Genes and Viruses: Who Wins The War?Conditional Targeted Deletions in Plasmodium falciparum...Designing and Mining Pathogen Genome Databases: The Apicop...Development of Genetic Systems for Genetically Intractable...Development of New Genetic Tools to Identify Nutrient Upta...Ecological Influences on Pathogen Genome EvolutionEvolution of Virulence in Eukaryotic PathogensExploiting an Evolutionary Omission in Pathogenic RNA Viru...Exploring Novel Pathways of Immune Defenses Against Orally...Genomic Approach to Improved Immunogenicity of M. tuber...Genomic tools to characterize hypermutating Plasmodium fal...Investigation of Mechanisms Leading to Anemia at Low Paras...Molecular definition of the bacterial population of human ...Mycobacterium Tuberculosis Latency and Reactivation Tuberc...New Antibiotics from Environmental DNAOptimizing Immunity to Complex Pathogens In VivoPandora's Box ProjectProviding an Economic Benefit to Using a Vaccine to Enhanc...Resistance Gene Flow in the Human Colonic MicrofloraRole of Nucleotide Binding Domain-Leucine Rich Repeat Prot...Sexually Transmitted Disease Agents in the “Healthy” Human...Systematic Analysis of Positive-strand RNA Viral Transmiss...The Human Intestinal Microbiome: Community Analysis, Host ...The Molecular Ecology of Vibrio cholerae in the Gangetic D...The Natural History of Typhoid Infection in VietnamThe Role of Quorum Sensing in Fungal DiseaseTowards Broad-spectrum Antivirals: Functional Screens for ...Transmission Blocking Vaccines for TuberculosisTransmission-blocking Vaccines Against Arthropod VectorsViral Pathogenic Mechanisms Involving Z-DNA Binding Proteins Select an institution Albert Einstein College of Medicine of Yeshiva University Columbia University Harvard Medical School Harvard School of Public Health Harvard University Johns Hopkins School of Public Health Massachusetts Institute of Technology Mount Sinai School of Medicine New York University School of Medicine Rockefeller University Stanford University School of Medicine Stanford University School of Medicine, VA Palo Alto Health Care System University of California - Berkeley University of California - Irvine University of California - San Diego University of California - San Francisco University of Illinois - Urbana-Champaign University of Pennsylvania University of Texas Southwest Medical Center University of Virginia University of Washington Washington University Washington University School of Medicine Weill Medical College of Cornell University Whitehead Institute for Biomedical Research Yale University School of Medicine

John C. Boothroyd, Ph.D. Stanford University School of Medicine

We are using the protozoan parasite, Toxoplasma gondii, as a model for studying the role of sex in the evolution of virulence in eukaryotic parasites. T. gondii is one of the most “successful” parasites on earth, at least in terms of warm-blooded animals: it is found world-wide, in a vast number of warm-blooded animal species and at high prevalence (e.g., 10-80% of humans, depending on the region). It can reproduce limitlessly through asexual reproduction or it can undergo classic sexual reproduction. This unusual choice gives the species both the ability to experiment with new gene combinations following sexual recombination as well as the opportunity to asexually expand any given progeny that happened on just the right genetic make-up to great numbers. As a result, it appears that a few genetically identical, clonal lines of this parasite have come to dominate in many parts of the world.

Our goal is to further understand how the combination of sexual and asexual reproduction have impacted the evolution of this parasite, especially in terms of its disease-causing properties in humans and other animals. We will be comparing the progeny of a sexual cross to determine how quickly new strains can arise, what genes influence the virulence and how large a role this process plays in the evolution of this parasite in nature. The results should have broad significance for our understanding of other eukaryotic pathogens that rely on sexual exchange for their evolution.

Contact Dr. Boothroyd.