Biardi, James - Fairfield University

个人简介

Dr. James Biardi is a vertebrate ecologist with interests in how small mammals defend themselves against predation from venomous snakes. His current research focuses on population and species differences in serum-based factors in small mammals that neutralize rattlesnake venom toxins. He has mentored over a dozen undergraduates in his laboratory at Fairfield, and has published several articles and abstracts co-authored with Fairfield students. Dr. Biardi is also actively involved in initiatives for science students on campus, including service as President of the Fairfield University Chapter of Sigma Xi, and service learning opportunities in watershed ecology for undergraduate students. He is also involved in sustainability initiatives on campus, including the Program on the Environment, the Faculty Committee on Sustainability, and the Campus Sustainability Committee.

研究领域

Research in my lab focuses on the ability of some organisms to neutralize the venom of snakes that prey on them. Snake venoms are some of the most complex biochemical mixtures produced in nature. They are crucial to the foraging success of the snake, since they function to ensure the efficient capture and digestion of prey. Once injected, rattlesnake venoms may produce a variety of symptoms in susceptible prey, including hemorrhage, myonecrosis, edema, shock, and paralysis. These effects are due to a variety of enzymes, polypeptides, amines, and other bioactive molecules. However, toxicity is not solely a property of the venoms per se, but an outcome of interaction between toxins and prey tissues. Therefore, it is critical to understand the function of venom components against prey. Unfortunately, most of our knowledge about the effects of snake venom comes from the biomedical literature, where studies traditionally employ laboratory strains of mice, rats, or rabbits. Although poorly understood, prey resistance is a potentially critical factor affecting the enormous variation revealed by studies of biochemical activity, electrophoretic profiles, and proteomic analysis of snake venoms. Over the past century a small number of mammal species have been identified that can survive envenomation by snakes with few or no significant effects. Studies of a handful of other resistant mammals suggest resistance is due primarily to innate antihemorrhagic proteins circulating in the blood. This is only a limited view of venom toxicity and resistance—a system that necessarily involves not only molecules, but the ecological and phylogenetic context of envenomation. While the molecular interactions between toxins and prey tissues are important, they also have a clear impact on fitness in an evolutionary sense. Resistance and toxicity provide an excellent system for studying a myriad of questions about adaptive variation and coevolution at the molecular level, while simultaneously raising population, species, and community level questions. Our analysis of squirrel serum samples detected patterns of population and species level variation in the outcome of interactions between toxins and resistance factors that suggest adaptation by both species (Biardi et al., 2000). Exploring activity of venom toxins against natural prey can uncover new knowledge that will be intriguing to evolutionary biologists, biochemists, and ecologists. In fact, our work on differences in resistance between S. beecheyi populations revealed previously cryptic variation in venom activity when assayed against prey sera (Biardi et al., 2006), variation not previously detected with in vitro or in vivo tests. This approach is inherently interdisciplinary. Therefore, I have chosen to unite graduate training in ecology and evolutionary biology with postdoctoral work in protein chemistry and proteomics to address problems in an integrated fashion. My primary goal as a research mentor is to help students understand the synergy of multiple perspectives on a research question, and therefore appreciate the strengths of broad training in biology. To advance this research I encourage participation in my lab from students interested in the molecular basis of toxicity or resistance, alongside students interested in the ecology and evolution of organisms under predation from venomous snakes. I have mentored 15 undergraduates on research projects during the last six years. Each has worked directly on tasks collecting original data using lab techniques (chromatography, enzymatic assays, protein electrophoresis), as well as field methods (for studies of small mammals), and statistical and computational tools for the analysis of comparative datasets. Undergraduate students completing capstone research projects in my lab have gone on to graduate programs in science, medical school, pharmacy school, and law school. Six students are already published coauthors (Biardi et al., 2006; 2011a, b).

近期论文

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Holding, M.L., Biardi, J.E., and Gibbs, H.L. (2016) Coevolution of venom function and venom resistance in a rattlesnake predator and its squirrel prey. Proc. R. Soc. B 283:2015–2841. Biardi, J.E., Ho, L.C.*, Marcinczyk, J.M.*, and Nambiar, K.P. (2011) Isolation and characterization of a snake venom metalloprotease inhibitor from California ground squirrel (Spermophilus beecheyi) blood sera. Toxicon 58:486–493. Biardi, J.E., Nguyen*, K.T., Lander*, S., Whitley*, M., and K.P. Nambiar. (2011) Development and validation of a rapid and sensitive fluorescence-based assay of snake venom metalloprotease activity. Toxicon 57:342-347 Biardi, J.E., and Coss, R.G. (2011) Rock squirrel (Spermophilus variegatus) blood sera affects proteolytic and hemolytic activities of rattlesnake venoms. Toxicon 57:323–331. Biardi, J.E. (2008) The ecological and evolutionary context of mammalian resistance to pitviper venoms. Pp. 557-568 in W.K. Hayes, K.R. Beaman, M.D. Cardwell and S. P. Bush (eds.) The Biology of Rattlesnakes. Loma Linda, CA: Loma Linda University Press. Biardi, J.E, D.C. Chien*, and R.G. Coss. (2006) California ground squirrel (Spermophilus beecheyi) inhibition of rattlesnake venom digestive and hemostatic toxins. Journal of Chemical Ecology 32(1):137-54. Biardi, J.E. R.G. Coss, and D.G. Smith. (2000). California ground squirrel (Spermophilus beecheyi) blood sera inhibits crotalid venom proteolytic activity. Toxicon 38: 713-721. Coss, R.G. and J.E. Biardi. (1997). Individual variation in the antisnake behavior of California ground squirrels (Spermophilus beecheyi). Journal of Mammalogy 73: 294-310. Kohn, J.R. and J.E. Biardi. (1995). Outcrossing rates and inferred levels of inbreeding depression in gynodioecious Cucurbita foetidissima (Cucurbitaceae). Heredity 75: 77-83. Smith, F., B. Bestelmeyer*, J. Biardi*, and M. Strong. (1993). Anthropogenic extinction of the endemic woodrat Neotoma bunkeri from Isla Coronado, Baja California, Mexico. Biodiversity Letters 1:149-155