INSECT-VECTORED PROTOZOAN PARASITES
BEETHAM
Research on protozoan parasites focusing on regulation of pathogenesis and the characterization of host-parasite-vector interactions, emphasizing Leishmania chagasi as a model system. Leishmania spp. are sandfly-vectored protozoan parasites that infect mammals and other vertebrates causing a collection of diseases that vary in severity from the self-healing to the potentially fatal. The goals of current research include (1) to determine how Leishmania survive the innate immune response of mammals and specifically to identify genes that confer parasite resistance to serum lysis. Among candidate genes/proteins that may function in parasite resistance to serum lysis is GP46, a predominant Leishmania surface glycoprotein. GP64 is normally upregulated only on serum-sensitive parasites and confers serum resistance when expressed on serum-sensitive parasites. We are conducting mechanistic studies of GP46 function in serum resistance; (2) to determine mechanisms by which Leishmania regulate gene and protein expression during development and acquisition of pathogenesis. Leishmania spp. are unusual among eukaryotes in their almost complete reliance on post-transcriptional processes to regulate type-II gene expression; gene regulation at transcription is extremely rare. Furthermore, RNA processing in Leishmania is quite different from that which occurs in most eukaryotes, and molecules that function in RNA processing events (including those events that affect RNA stability) are therefore likely to be very different from the analogous factors of other eukaryotes. Understanding the mechanism by which Leishmania modulate the mRNA abundance of developmentally regulated genes/proteins, or by which the parasites survive innate host immune responses, may identify candidate molecular targets for new disease treatment modalities.
Project Leader
Jeffrey Beetham - Associate Professor
Research Associates (P&S)
Christian Bartholomay. Characterization by quantitative PCR of transcript levels for genes that are differentially expressed during parasite development.
Dennis Byrne. Isolation and characterization of membrane proteins from infectious and non-infectious stage parasites.
Postdoctoral Researcher
Amanda Ramer.
Research Assistants (PhD Students)
Rebecca Laborde (Genetics). Reverse genetics approach towards the identification and characterization of genetic elements conferring resistance to human-serum lysis.
Samantha Lei (MCDB/Entomology). Developmental biology of parasites as they progress to an infectious stage that resists lysis by human serum.
Nathan Romine (Genetics). Reverse genetics toward characterizing parasite proteins that influence serum-lysis sensitivity, and biocomputational approach toward identifying unique pathways or unique aspects of pathways in the parasite that might serve as targets for prevention or treatment modalities.
Eric Scolaro (Microbiology/Entomology). Mechanism of action of surface protein GP46 in parasite resistance to innate immune responses of mammalian hosts.
NOVEL APPROACHES TO INSECT PEST CONTROL
BONNING
The goal of Bonning's research program is to develop novel approaches for insect pest management. Current projects include use of small RNA viruses for management of aphid pests, optimization of recombinant baculovirus insecticides for lepidopteran pests, and production of insect resistant transgenic plants.
Project Leader
Bryony Bonning - Professor
Assistant Scientist (P&S)
Sijun Liu. Plant resistance to insect pests mediated by a protease.
Postdoctoral Research Associate
Huarong Li. Development of novel aphicidal toxins for use in transgenic plants.
Research Assistants (PhD Students)
Nina Richtman (Entomology). Mechanism for increased black cutworm susceptibility to baculovirus following Bt toxin exposure. Development of novel aphicidal toxins for use in transgenic plants.
Wendy Sparks (Genetics). Functional analysis of positively selected baculovirus envelope proteins and their role in baculovirus interaction with the lepidopteran gut.
Hailin Tang (Toxicology). Physiological basis for insecticidal action of a basement membrane-degrading protease.
PESTICIDE TOXICOLOGY
COATS
The major goals of the Coats laboratory are to educate and train scientists in insect toxicology and environmental toxicology/chemistry of agrichemicals, as well as contribute to the advancement of the science in these areas. (1) The insect toxicology portion of the laboratory is focused primarily on natural products as insecticides and insect repellents, considering modes of action, identification, specificity, metabolism, quantitative structure-activity relationships, and synthesis. (2) The environmental toxicology and chemistry part of the laboratory is focused on the environmental fate and effects of agrichemicals. Current projects include investigations on the environmental fate and effects of conventional pesticides, veterinary antibiotics, Bt protein toxins and vaccines produced by transgenic plants.
Project Leader
Joel Coats - Professor
PhD Student
Keri Henderson (Toxicology Research Fellow: Tom Moorman, USDA, co-advisor). Environmental fate of the veterinary antibiotics tylosin and sulfamethazine, including degradation in soil and water, as well as leaching studies in intact soil columns; methods for assessing bioavailability of the antibiotics in soil and water. Possible impact of the antibiotics on microbial communities in the environment.
Research Assistants (PhD Students)
Dingfei Hu (Toxicology). Environmental fate of monoterpenoid insecticides, including degradation in soil and water, as well as leaching studies in packed soil columns; analytical methodology for detection/quantification of the veterinary antibiotic tylosin, using HPLC, including the cross-reactivity among the factors in ELISA assay.
Gretchen Paluch (Entomology & Toxicology Lab Coordinator: Bartholomay, co-advisor). Identification, characterization, biological activity, and mode of action of botanical insect repellents, especially terpenoids; design of novel insect bioassays and screening techniques.
Fan Tong (Toxicology). The mechanism of action of monoterpenoid insecticides in insects, focused on biochemical neurotoxicological assays; molecular modeling of terpenoids' insecticidal activity.
Research Assistants (MS Students)
Aaron Gross (Toxicology). Isolation, identification, and characterization of natural insecticides and repellents.
Ashley Jessick (Toxicology). Environmental fate of veterinary antibiotics, including persistence, mobility, bioavailability, and biotransformation.
Hirofumi Kosaki (Toxicology: Jeff Wolt, Agronomy, co-advisor). Development of methodology for quantifying residues of biopharming proteins from environmental matrices; studies on the environmental fate and effects of vaccines produced in transgenic corn.
Ian Murphy (Toxicology). Environmental chemistry and toxicology of agrichemicals, including phytoremediation of pesticides.
SYSTEMATICS AND AQUATIC ENTOMOLOGY
COURTNEY
The focus of Courtney's research is the systematics and ecology of aquatic insects. Specific areas of study include phylogeny of dipteran families; morphology, phylogeny, biogeography, and historical ecology of aquatic insects; biodiversity and conservation of aquatic habitats; and use of aquatic insects as indicators of water quality.
Project Leader
Gregory Courtney - Professor of Entomology and Chair of Ecology & Evolutionary Biology Program
Research Assistants (PhD Students)
Rebecca Brown (Entomology/Ecology and Evolutionary Biology). Phylogenetic analysis of the Edwardsininae (Diptera: Blephariceridae), including revision of the genus Paulianina Alexander.
Jessica Davis (Entomology/Ecology and Evolutionary Biology). Revision of the genus Phylidorea Bigot (Diptera: Tipuloidea), with investigations into nodes of speciation.
Matthew Petersen (Entomology/Ecology and Evolutionary Biology). Phylogenetic classification of the Tipuloidea with an emphasis on the distribution, diversification, and character evolution of the subfamily Limoniinae (Limoniidae).
Research Assistant (MS Student)
Matthew Wihlm (Entomology). Systematic revision of the Axymyiidae (Diptera).