- Author: Kathy Keatley Garvey
Claudio Gratton, associate professor in the Department of Entomology, University of Wisconsin, will speak on “Sustainable Bioenergy Landscapes: Can We Balance Our Need for Production and Biodiversity?” at a UC Davis Department of Entomology seminar on Wednesday, April 10.
His seminar will take place from 12:05 to 1 p.m. in Room 1022 of the Life Sciences Addition, corner of Hutchison and Kleiber Hall drives. Katharina Ullmann of the Neal Williams lab is the host. The seminar is scheduled to be recorded for later viewing on UCTV.
“Increasing demands for food, and now fuel, have put pressure on our agricultural lands,” Gratton says. “Land use and land cover are continuing to change the way we manage our lands with significant biological and ecosystem-level consequences.”
“The ‘simplification’ of the agricultural landscape, that is the removal of natural and semi-natural areas in the landscape and the increase in monocultures of annual crops, is typically associated with a decrease in species richness and increases in crop pest abundance,” he said. “These effects go beyond mere aesthetics. The consequences of landscape simplification are felt by growers who apply more pesticides in landscapes dominated by annual cropland. The question then, is can we balance our needs for agricultural production (both food and fuel) in a way that supports other ecosystem services on which we as humans depend?”
“I argue that understanding the relationships between landscape structure and the tradeoffs between ecosystem services will be a key a designing ‘custom’ multifunctional landscapes.”
Gratton, who has a bachelor of science degree in biology from the University of Illinois (1991) and a doctorate in entomology from UC Berkeley (1997), joined the University of Wisconsin faculty in 2003. His research group works broadly in the field of landscape ecology in both agricultural and natural systems. In Wisconsin agriculture, he has been interested in understanding how beneficial insects, such as pollinators and lady beetles, utilize the landscape and carry out important functions such as pollination of crops and suppression of insect pests.
His work in agroecology has included studying insect landscape ecology and conservation in potatoes, rotational grazing, grasslands, soybeans, cranberries and apples.
Gratton has worked with growers to understand how to best manage non-crop “natural” areas in the landscape in order to enhance and conserve beneficial insects. He is also an active member of the Great Lakes Bioenergy Research Center as part of the team looking at developing sustainable bioenergy crops. He teaches courses in insect biological control, multivariate analysis and coastal field ecology.
- Author: Kathy Keatley Garvey
In research led by postdoctoral researcher Zuodong Zhang, a team of 16 scientists discovered a key mechanism by which dietary omega-3 fatty acids (fish oils) could reduce the tumor growth and spread of cancer, a disease that kills some 580,000 Americans a year.
The research is published today (April 3) in the Proceedings of the National Academy of Sciences (PNAS). They discovered cytochrome P450 epoxygenase metabolites of omega-3 fatty acid DHA or epoxy docosapentaenoic acids (EDPs) block blood supply to the tumor and thus inhibit tumor growth and metastasis.
The natural EDPs were further stabilized by a drug called a soluble epoxide hydrolase inhibitor which is already under development to control pain and hypertension.
“Many human studies have shown that omega-3 fatty acids reduce the risks of cancers, but the mechanism is poorly understood,” said Zhang, a postdoctoral researcher who focuses his research on lipid mediators on angiogenesis, tumor growth and metastasis. “Our study provides a novel mechanism by which these omega-3 lipids inhibit cancer.”
“We demonstrated that EDPs have very potent anti-cancer and anti-metastatic effects,” Zhang said. “Current anti-cancer drugs that block angiogenesis (the formation of new blood vessels to fuel tumor progression) can cause serious side effects such as hypertension. By blocking angiogenesis by a new mechanism and by widening blood vessels, EDPs could block tumor growth with reduced side effects in cancer patients.”
The studies, conducted on mice, also suggest that a combination of omega-3 diet and some anti-cancer drugs such as sorafenib, “could not only be efficacious to treat cancers but reduce potential side effects,” said Zhang, who received his doctorate in food science from the University of Wisconsin-Madison.
“Thus the effects of the soluble epoxide hydrolase inhibitors have opposite effects depending on whether the background lipid mediators are omega 3 or omega 6,” Hammock said. “Assuming that humans are mice (the study involved mice), the prediction is that with some cancer drugs--particularly the ones like sorafenib and regorafenib that are potent epoxide hydrolase inhibitors as well as anti-angiogenic agents--these could be more effective with a high omega 3 and low omega 6 background.”
“This is an exciting step towards our full appreciation of the impact of bioactive products from the DHA metabolome,” said Charles Serhan of Harvard Medical School, an expert on omega-3 autacoids and inflammation who is the Simon Gelman Professor of Anesthesia, Periopterative and Pain Medicine, Harvard Medical School. “This (UC Davis) contribution places metabolic conversion of omega-3 DHA to epoxy DHA products pivotal in vascular mechanisms key in cancer and vascular biology. It will be exciting to watch these important findings translated to humans for new evidence based treatments for angiogenesis, tumor growth and cancer metastasis.”
Said cardiologist Jonathan Lindner of the Oregon Health & Science University: “New drug strategies for fighting cancer could emerge from knowledge of how the body uses nutrition to promote health. Diet has been shown to influence susceptibility to many types of cancer, and also to influence rate of tumor progression and response to chemotherapy. This information has been leveraged to make reasonable recommendations on diet in patients with cancer. Perhaps more importantly, by uncovering how diet influences tumor development and growth, it may be possible to develop new drugs that work through the same beneficial pathways.”
“The study by Zhang and colleagues has uncovered a previously unrecognized anti-cancer effect of omega-3 fatty acids which are an important lipid component of diets that have been developed to prevent heart disease and cancer,” Lindner said. “The authors have demonstrated that metabolites of these lipids can act to suppress the growth of new blood vessels that are necessary to feed tumor growth. By shutting off the tumor’s blood supply, these compounds can act to dramatically slow tumor growth and prevent metastasis. The results from this suggest that new drug strategies for fighting cancer could emerge from knowledge of how the body uses nutrition to promote health.”
Read more about the research on the UC Davis Department of Entomology website and see photos of some of the co-authors.
- Author: Kathy Keatley Garvey
It promises to be a lively discussion.
UC Davis entomologist Bruce Hammock, distinguished professor of entomology, will speak on “From Butterflies to Blood Pressure and Beyond: Is It Possible to Get a Drug to the Clinic with a University’s Help?” at a Science Café session set Wednesday, April 3 at 5:30 p.m. in Crepeville, 330 3rd St., Davis.
The session, open to the public and billed as “a conversation with Professor Bruce Hammock,” will be hosted by the UC Davis Division of Math and Physical Sciences. Co-sponsor is the Department of Chemistry. Professor Jared T. Shaw will introduce Hammock.
Said Hammock: “The science is how basic research on insects has led to a drug for blocking hypertension and neuropathic pain. The general discussion is on the difficulties of translating basic science paid for by the taxpayer, into a technology that can actually help the taxpayer.”
Hammock, a member of the UC Davis Department of Entomology faculty since 1980, holds a joint appointment with the UC Davis Comprehensive Cancer Research Center, and directs the campuswide Superfund Research Program, National Institutes of Health Biotechnology Training Program, and the National Institute of Environmental Health Sciences (NIEHS) Combined Analytical Laboratory.
He is a fellow of the Entomological Society of America, a member of the prestigious National Academy of Sciences, and the recipient of the 2001 UC Davis Faculty Research Lecture Award and the 2008 Distinguished Teaching Award for Graduate and Professional Teaching.
- Author: Kathy Keatley Garvey
That's the title of a newly published book written by Robert E. Page Jr., one of the world's foremost honey bee geneticists.
In his 224-page book, published by Harvard University Press, Page sheds light on how 40,000 bees, "working in the dark, seemingly by instinct alone, could organize themselves to contstruct something as perfect a a honey comb."
Page, former professor and chair of the UC Davis Department of Entomology, marvels at how bees can accomplish these incredible tasks. In synthesizing the findings of decades of experiments, he presents "a comprehensive picture of the genetic and physiological mechanisms underlying the division of labor in honey bee colonies and explains how bees' complex social behavior has evolved over millions of years," according to the Harvard University flier.
Page, now vice provost and dean of the Arizona State University's College of Liberal Arts and Sciences and Foundation Professor of Life Sciences, still keeps his specialized stock of honey bees at the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis. Bee breeder-geneticist Michael “Kim” Fondrk, who worked with Page at Ohio State University, UC Davis and ASU, manages the stock.
In his book, Page talks about the coordinated activity of the bees and how worker bees respond to stimuli in their environment. The actions they take in turn alter the environment, Page says, and "so change the stimuli for their nestmates. For example, a bee detecting ample stores of pollen in the hive is inhibited from foraging for more, whereas detecting the presence of hungry young larvae will stimulate pollen gathering."
Division of labor, Page says, is an inevitable product of group living because "individual bees vary genetically and physiologically in their sensitivities to stimuli and have different probabilities of encountering and responding to them."
Page, who received his doctorate in entomology at UC Davis in 1980, served as an assistant professor at Ohio State University before joining the UC Davis Department of Entomology in 1989. He chaired the department for five years, from 1999 to 2004.
In 2004--the year Page retired from UC Davis--ASU recruited him as the founding director and dean of the School of Life Sciences. At the time, his duties included organizing three departments—biology, microbiology and botany, totaling more than 600 faculty, graduate students, postdoctoral fellows and staff--into one unified school.
As its founding director, Page established the school as a platform for discovery in the biomedical, genomic and evolutionary and environmental sciences. He also established ASU’s Honey Bee Research Facility.
Page is a highly cited author on such topics as Africanized bees, genetics and evolution of social organization, sex determination, and division of labor in insect societies.
Add this one to the list: The Spirit of the Hive.
- Author: Kathy Keatley Garvey
Plants communicate. They do.
Ecologist Richard Karban, a professor in the UC Davis Department of Entomology, points out that one of the simplest forms of communication involves shade.
When a plant is shaded, it grows away from the plant or other object that's shading it.
Today he published research in the Proceedings of the Royal Society B: Biological Sciences that is truly amazing readers. It involves kinship, communication and defenses.
Basically, if you’re a sagebrush and your nearby kin is being eaten by a grasshopper, deer, jackrabbit, caterpillar or other predator, it’s good to be closely related. Through volatile (chemical) cues, your kin will inform you of the danger so you can adjust your defenses.
If you’re not closely related, communication won’t be as effective.
Kin have distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors," Karban says. For example, fire ants can recognize kin. “Ants will destroy queens that are not relatives but protect those who are."
That ability is less well studied for plants--until now.
“When sagebrush plants are damaged by their herbivores, they emit volatiles that cause their neighbors to adjust their defenses,” Karban said. “These adjustments reduce rates of damage and increase growth and survival of the neighbors.”
“When sagebrush plants are damaged by their herbivores, they emit volatiles that cause their neighbors to adjust their defenses,” Karban said. “These adjustments reduce rates of damage and increase growth and survival of the neighbors.”
“Why would plants emit these volatiles which become public information?” he asked. “Our results indicate that the volatile cues are not completely public, that related individuals responded more effectively to the volatiles than did strangers. This bias makes it less likely that emitters will aid strangers and more likely that receivers will respond to relatives.”
The research, “Kin Recognition Affects Plant Communication and Defense,” is co-authored by two scientists from Japan and two from UC Davis: Kaori Shiojiri of the Hakubi Center for Advanced Research, Kyoto University, and Satomi Ishizaki of the Graduate School of Science and Technology, Niigata University; and William Wetzel of the UC Davis Center for Population Biology, and Richard Evans of the UC Davis Department of Plant Science.
To simulate predator damage, the researchers “wounded” the plants by clipping them and then studied the responses to the volatile cues. They found that the plants that received cues from experimentally clipped close relatives experienced less leaf damage over the growing season that those that received cues from clipped neighbors that were more distantly related.
“More effective defense adds to a growing list of favorable consequences of kin recognition for plants,” they wrote.
The researchers performed their field work on sagebrush (Artemisia tridentata) at Taylor Meadow, UC Sagehen Creek Field Station, near Truckee. They conducted four field experiments over three years “that compared the proportion of leaves that were damaged by herbivores over the growing season when plants were provided with volatile cues clipped from a close relative versus cues from a distant relative,” the scientists wrote.
For closely related kin, they snipped stem cuttings (clones), potted them, and then returned the pots to the field. They determined relatedness “by using microsatellites that varied among individual sagebrush clones.”
The result: “Plants responded more effectively to volatile cues from close relatives than from distant relatives in all four experiments and communication reduced levels of leaf damage experienced over the three growing seasons,” they wrote. “This result was unlikely to be caused by volatiles repelling or poisoning insect herbivores.”
Karban, who has studied plant communication among the sagebrush at the site since 1999, likened the plant communication to neighbors “eavesdropping.” They “hear” the volatile cues of their neighbors as predators damage them.
Eavesdropping. Kinship. Plant communication. Plant defenses.
Fascinating stuff.
Who knew?