Department's Winter Quarter Seminars Announced
Seminar coordinator and associate professor Brian Johnson has announced the list of UC Davis Department of Entomology and Nematology seminars for the winter quarter, from Jan. 8 through March 11.
All seminars will be on Mondays at 4:10 p.m. in Room 122 of Briggs Hall and also will be on Zoom.The Zoom link: https://ucdavis.zoom.us/j/95882849672.
No seminar will take place on Monday, Jan. 15, which is Martin Luther King Jr. Day, a university holiday.
Adler Dillman
Professor of parasitology and nematology, and chair of the Department of Nematology, UC Riverside
Title: "Nematode Parasitism of Insects with Toxic Cardenolides"
Abstract: (Partial) "Target-site insensitivity (TSI) is an important mechanism of animal resistance to toxins. TSI evolved in parallel in the monarch butterfly and other insects that specialize on milkweeds and is thought to have facilitated sequestration of cardiac glycosides (CGs) that may protect these insects from predation and parasitism....Our results suggest that a molecular evolutionary cascade of parallel substitutions across hosts and parasites, last sharing common ancestry 600 million years ago, may shape multitropic interactions across plant communities."
Biography: He holds a bachelor's degree in microbiology from Brigham Young University (2006) and a doctorate in genetics (2013) from the California Institute of Technology.
William Ja
Associate professor, Herbert Wertheim Scripps UF Institute for Biomedical Innovation and Technology in Jupiter, Florida.
Title: "Eat, Excrete, & Die: Regulation of Homeostatic Behaviors and Aging in Drosophila"
Abstract: "The Ja lab uses the fruit fly, Drosophila melanogaster, as a model organism for uncovering the genetic and neuronal mechanisms that drive aging, behavior, and disease. Recently developed tools allow us to track fly feeding behavior with unparalleled resolution. These tools facilitate the identification of genes and circuits that regulate food intake at diverse time scales, including studies of: 1) meal intake; 2) daily (circadian) feeding rhythms; and 3) compensatory feeding in response to high or low quality food. Our studies of feeding behavior and nutrition also inform aging interventions, including a novel caloric restriction paradigm and an intermittent fasting regime that extends fly life through the stimulation of circadian-regulated autophagy. Overall, our fly studies shed light on basic neurobiological principles that drive animal behavior, providing insights that potentially inform the development of conserved therapeutic strategies."
Biography: Ja received his chemistry degree at UC Berkeley, working with Richard Mathies and Alex Glazer on DNA sequencing technologies. He pursued doctoral studies at the California Institute of Technology with Rich Roberts, utilizing mRNA display technology to identify modulators of G protein signaling. Ja remained at Cal Tech as a postdoctoral scholar to work with Seymour Benzer on developing longevity ‘drugs' in Drosophila. His laboratory focuses on aging and nutrition, animal behavior, and host-microbiome interactions.
Todd Johnson
Assistant professor of forest entomology, Louisiana State University
Title: "Characterizing Ecological Interactions of Arthropods in Forests under Global Change'
Abstract: "Forests cover approximately 30% of the Earth's landmass and provide important ecosystem services that include food, fuel, and timber, as well as habitat for diverse organisms. Threats posed to forests by invasive and pestiferous species are rapidly growing. Global change, an umbrella term that includes may human-mediated processes such as climate change and international trade, is altering the structure and functioning of forests. Our recently formed research group studies how natural variation impacts the outcomes of interactions between trees, herbivores, and the natural enemies of herbivores. My seminar will provide an overview of our ongoing and developing studies to better understand how variation in chemistry across the landscape shapes the fitness of woodboring insects, and how this variation can be harnessed to optimize management of forest ecosystems."
Biography: His research group studies the behavioral and chemical ecology of forest arthropods, with an emphasis on building fundamental knowledge that can further our understanding and management of natural and managed ecosystems. Johnson received his bachelor's degree in biology from Moravian College, his master's degree in entomology from the University of Wisconsin-Madison, and his doctorate from the University of Illinois at Urbana-Champaign. Prior to accepting his position at LSU in the fall of 2022, he was a postdoctoral research associate at the University of New Hampshire.
Orie Shafer
Professor of biology and cognitive neuroscience, City University of New York
Title: "Circadian and Homeostatic Regulation of Fly Sleep"
Abstract: "Sleep-like states are ubiquitous in the animal kingdom and are regulated by two distinct forms of regulation, circadian and homeostatic. Homeostatic mechanisms promote increases in sleep pressure during prolonged wakefulness. Circadian mechanisms determine the likelihood of sleep, increasing or decreasing its probability across the day. Though the molecular and neural mechanisms of circadian timekeeping are relatively well-understood, much less is known about the mechanistic basis of sleep homeostasis. The fly Drosophila melanogaster is a powerful model organism for the studying of sleep regulation. In this talk I will describe recent work from my lab examining how circadian timekeeping and sleep homeostasis operate in this fly and how these two regulatory processes converge to produce the proper timing and amount of sleep."
Biography: He received his doctorate in biology from the University of Washington, and served as a postdoctoral researcher at Washington University School of Medicine, St. Louis.
Peter Piermarini
Professor and associate chair of entomology, The Ohio State University, Wooster
Title: "Discovery of Novel Chemical Tools for Controlling the Most Dangerous Animals on Earth"
Abstract: "Mosquitoes are considered the most dangerous animals on Earth due to the deadly pathogens they transmit to humans. Controlling the transmission of mosquito-borne diseases often relies on chemical tools that prevent mosquitoes from biting humans (e.g., insecticides, repellents). However, the evolution of resistance in mosquitoes to commonly used control agents with similar modes of action has generated a need to discover novel chemistries for killing and/or repelling mosquitoes. To address this need, my lab is engaged in collaborative research that is discovering synthetic small molecules to disrupt novel physiological targets in mosquitoes and screening natural products for insecticidal and repellent activity against mosquitoes. My talk will summarize examples for each of these approaches and their potential for development into novel mosquito control tools."
Biography: He received his bachelor's degree in biology from James Madison University and doctorate in zoology from the University of Florida, before completing postdoctoral training at the Yale University School of Medicine and Cornell College of Veterinary Medicine. His laboratory studies the molecular physiology and toxicology of mosquitoes with the goal of discovering and developing insecticides with novel modes of action.
Monday, Feb. 26
Title: "“Advances and Innovations in the Characterization of Molecular Interactions Between
Frankliniella occidentalis and Tomato Spotted Wilt Virus.”
Biography: Dorith (pronounced Doreet) Rotenberg received three degrees from the University of Wisconsin-Madison: bachelor of science degree in biochemistry and her master's and doctorate in plant pathology. She is a professor in the Department of Entomology and Plant Pathology at North Carolina State University (NCSU) and the director of Graduate Programs in Plant Pathology. She co-directs the NCSU Plant Virus Vector Interactions Lab. Her foundational research initiatives center on the long-range goal of identifying and characterizing insect vector determinants of plant virus transmission to crop plants using a combination of ecological and genomics-based tools. Her research program has provided to the international science community vector genome, transcriptome, and proteome sequence resources to dig deeply into commonly-shared questions revolving around insect evolution, development, and transmission biology.
Abstract: "Arthropod-transmitted plant pathogens cause crippling monetary losses to U.S. and global economies. Tomato spotted wilt virus (Order Bunyavirales, family Tospoviridae, genus Orthotospovirus) is one of those pathogens, and it is transmitted in a circulative-propagative manner by Frankliniella occidentalis, the principal thrips vector. The overarching goal of my research program is to contribute fundamental knowledge towards developing alternative, effective and innovative tools for diminishing vector-transmitted crop diseases. My lab has been on the forefront of generating and sharing vector ‘omics resources to enable the identification and characterization of molecular determinants of vector competence as a means to specifically disrupt the virus transmission cycle. Using a combination of proteomic, transcriptomic and functional tools developed by my team and collaborators for F. occidentalis and TSWV, we aim to drill down on gut proteins associated with thrips host response to virus activities (indirect interactions) and/or gut proteins that physically interact with the viral attachment protein (GN) (direct). My talk will cover research advances made towards identifying and functionally characterizing two promising gut-expressed proteins, and new tools to interrogate F. occidentalis genes associated with virus transmission."
Salil Bidaye
Research Group Leader, Max Planck Florida Institute for Neuroscience
Title: "How Flies Control How They Walk by Knowing When and How to Stop"
Abstract: "Walking is a complex motor program involving coordinated and distributed activity across the brain and the spinal cord. Halting appropriately at the correct time is a critical but often overlooked component of walking control. While recent studies have delineated specific genetically defined neuronal populations in the mouse brainstem that drive different types of halting, the underlying neural circuit mechanisms responsible for overruling the competing walking-state neural activity to generate context-appropriate halting, remain unclear. Here, we elucidate two fundamental mechanisms by which Drosophila implement context-appropriate halting. The first mechanism (“walk-OFF” mechanism) relies on GABAergic neurons that inhibit specific descending walking commands in the brain, while the second mechanism (“brake” mechanism) relies on excitatory cholinergic neurons in the nerve-cord that lead to an active arrest of stepping movements. Using connectome-informed models and functional studies, we show that two neuronal types that deploy the “walk-OFF” mechanism inhibit distinct populations of walking-promotion neurons, leading to differential halting of forward-walking or steering. The “brake” neurons on the other hand, override all walking commands by simultaneously inhibiting descending walking promoting pathways and increasing the resistance at the leg-joints leading to an arrest of leg movements in the stance phase of walking. We characterized two ethologically relevant behavioral contexts in which the distinct halting mechanisms were used by the animal in a mutually exclusive manner: the “walk-OFF” pathway was engaged for halting during feeding, and the “brake” pathway was engaged for halting during grooming. To our knowledge, this represents the first mechanistic understanding of halting in fruit-flies and hence a major step in our larger goal of uncovering the fundamental principles governing walking control in animals."
Biography: Bidaye studies neuronal control of locomotion."While a graduate student in Barry Dickson's lab in the beautiful city of Vienna, Austria, as I observed fruit-flies chasing each other during courtship, I got hooked on to the intricate control that comprises insect walking. This fascination kindled by powerful fly genetic tools, has led me to persistently device new behavioral assays and neural recording techniques, aimed at elucidating the fundamental control mechanisms that underlie the exquisite locomotor control that is commonplace in all animals."
Inga Zasada
Research plant pathologist, USDA-ARS Horticultural Crops Research Laboratory, Corvallis, Ore.
Title: "How an Applied Nematologist Uses Genomic Tools to Address Plant-Parasitic Nematode Research"
Abstract: "Advancements in molecular plant pathology have created an environment in which applied, field-based research programs have the opportunity to utilize genomic tools in their programs. There are potential rewards for incorporating genomics into a research program including enhanced nematode diagnostics, population genetics of infestations, and novel biological discoveries. However, along with these rewards come many considerations including cost, tempered expectations, and the capacity to generate and analyze data. A cautionary tale of such a journey will be presented. Efforts to characterize the nematode microbiomes from a diversity of plant-parasitic nematodes, understand the population genetics of a potato cyst nematode infestation, and sequence and annotate nematodes genomes will be presented to highlight the rewards and challenges of this type of research. Underpinning all of these efforts is the need to establish and maintain productive collaborations with scientists with diverse backgrounds."
Biography: Inga Zasada is a research plant pathologist with USDA-ARS. She received her doctorate in plant pathology from UC Davis. She has spent her entire career with USDA-ARS, first in Beltsville, MD and now in Corvallis, OR. Her research program focuses on the management of plant-parasitic nematodes in raspberry, wine grapes, potatoes and other high value crops.
For Zoom technical issues, contact seminar coordinator Brian Johnson, associate professor, at brnjohnson@ucdavis.edu.