Posts Tagged: Bruce Hammock
It's Halloween tomorrow (Wednesday) but what's really frightening is Aedes aegypti, a mosquito that transmits the deadly dengue. According to the World Health Organization (WHO), dengue is the world's most rapidly spreading mosquito-transmitted disease.
Some 2.5 billion people, or about 40 percent of the global population, are at risk from dengue, WHO says. The disease infects between 50 to 100 million people a year. The most severe form afflicts some 500,000 a year, killing an estimated 2.5 percent or 22,000.
Enter Sarjeet Gill, professor of cell biology and entomology at UC Riverside. He'll speak on on "Bacterial Toxins in Disease Mosquito Vector Control" at a seminar from 12:10 to 1 p.m., Wednesday, Oct. 31 in Room 1022 of the Life Sciences Building, UC Davis.
His longtime colleague and good friend, Bruce Hammock, distinguished professor of entomology at UC Davis, will host him as part of the UC Davis Department of Entomology's fall seminar series.
"Aedes aegypti is an important vector of human diseases, such as dengue fever and yellow fever," Professor Gill says. "Its control has been attempted by eliminating breeding sites, using predators and with chemical insecticides. However, such control is still difficult because of operational limitations and the development of insect resistance. Therefore, Bacillus thuringiensis has been used for decades instead of physical and chemical control methods. B. thuringiensis israelensis is highly active against Aedes aegypti."
"The high insecticidal activity and the low toxicity to other organisms," Gill says, "have resulted in the rapid use of B. thuringiensis as an alternative for the control of mosquito populations. B. thuringiensis israelensis produces a variety of toxins that act synergistically to cause toxicity to larval populations."
Gill says his seminar "will discuss our current understanding of the mode of action of these toxins and provide evidence on how resistance to these toxins has not occurred in Aedes mosquitoes in the field even though B. thuringiensis israelensis has been used for more than three decades."
Gill’s laboratory focuses on two principal research activities. "The first area attempts to elucidate the mode of action of insecticidal toxins from the Gram positive bacteria Bacillus thuringiensis and Clostridium bifermantans," he says. "This research aims to identify novel toxins, and to gain a molecular understanding of how these toxins interact with cellular targets and thereby causing toxicity. The second area focuses on understanding mosquito midgut and Malpighian tubules function, in particular ion and nutrient transport, and changes that occur following a blood meal."
Gill, who received his doctorate from UC Berkeley, joined the UC Riverside Department of Entomology faculty in 1983. He helped establish the Department of Cell Biology and Neuroscience and also served as chair. Currently he is the co-editor of the journal Insect Biochemistry and Molecular Biology.
A noted scientist and a fellow of the American Association for the Advancement of Science, Gill received his doctorate in insecticide toxicology in 1973 from UC Berkeley. See his website.
If you miss his seminar, not to worry. It's scheduled to be recorded and then posted at a later date on UCTV. (See the index of previous Department of Entomology seminars posted on UCTV.)/span>
Aedes aegypti transmits the deadly dengue. (Photo by James Gathany, Centers for Disease Control and Prevention)
Professor Sarjeet Gill at a malaria conference at UC Davis. (Photo by Kathy Keatley Garvey)
Scorpions--to fear or to revere?
The Bohart Museum of Entomology's open house last Sunday drew visitors of all ages who marveled at the scorpions glowing under ultraviolet light.
UC Davis entomology major Alexander Nguyen flashed a UV light on the critters as his audience watched in amazement.
Most--but not all--of the world's scorpions glow under ultraviolet light, says Lynn Kimsey, director of the Bohart Museum, which houses more than seven million insect specimens.
Scorpions are not insects, but arachnids, the same as spiders. Ranging in size from 9 mm to 21 mm, scorpions have eight legs (arachnid alert!) and grasping claws that help conquer their prey. But it's their venom that kills. And all scorpions possess venom.
UC Davis entomologist Bruce Hammock and his lab made the news back in 2003 when they published a study that showed that scorpions produce two venoms: a pre-venom to deter predators and immobilize small prey, and then the good stuff, the powerful venom that's meant to kill.
It's like saving the best for last or waiting for the venom glands to pump and reload, so to speak.
So, why do they glow?
Scientists believe it's because of the fluorescent material found in the scorpion's hard outer covering.
"The fact that they glow serves no physiological function," said Bohart senior museum scientist Steve Heydon. "It's probably a quirk of chemical makeup."
Great quote..."a quirk of chemical makeup."
Scorpion glowing under ultraviolet light at the Bohart Museum of Entomology. (Photo by Kathy Keatley Garvey)
UC Davis entomology undergraduate student Alexander Nguyen flashes a UV light on a scorpion, as Professor Demosthenes Pappagianis, M.D., Ph.D., of Medical Microbiology and Immunology, watches. (Photo by Kathy Keatley Garvey)
That's why we're looking forward to hearing Bryony Bonning speak on "Novel Toxin Delivery Strategies for Management of Pestiferous Aphids" at the next UC Davis Department of Entomology seminar, scheduled from 12:10 to 1 p.m., Wednesday, April 18 in 122 Briggs Hall.
Aphids, Bonning says, transmit more than 275 plant viruses "that result in considerable economic loss within the agricultural sector."
Now that's a lot of plant viruses!
A professor with the Iowa State University's Department of Entomology, Bonning is closely linked to UC Davis. She's a former postdoctoral research associate in the Bruce Hammock lab, Department of Entomology. Hammock, a distinguished professor of entomology, worked with her from 1990 to 1994. Her specialty: genetic engineering and optimization of baculovirus insecticides.
Bonning returns here Wednesday with lots of credentials. She's an associate editor for the Journal of Invertebrate Pathology; a Fellow of the American Association for the Advancement of Science (AAAS); a member of the International Committee on Taxonomy of Viruses, Baculovirus Study Group; and a member of the International Committee on Taxonomy of Viruses, Dicistrovirus/Iflavirus Study Group.
Bonning received her bachelor's degree in zoology from the University of Durham, UK in 1985, and her doctorate in applied entomology from the London School of Hygiene and Tropical Medicine, University of London, UK in 1989.
In her abstract for Wednesday's talk, Bonning explains: "Viruses in the Luteoviridae are obligately transmitted by aphids in a persistent manner that requires virion accumulation in the aphid hemocoel. To enter the hemocoel, the virion must bind and traverse the aphid gut epithelium. The molecular mechanisms involved in this process are poorly understood. By screening a phage display library, we identified a peptide that binds to the gut epithelium of the pea aphid Acyrthosiphon pisum (Harris) and impedes the update of Pea enation mosaic virus from the pea aphid gut into the hemocoel. In this talk, the development of two novel aphid management technologies based on knowledge of pea aphid – Pea enation mosaic virus molecular interactions will be described. These technologies provide enhanced delivery of both gut active and neurotoxic peptides."
"I can hardly wait for Bryony Bonning to visit us and present a seminar," Hammock said. "She is one of our most productive alumni in continuing her work on insect developmental biology and green pesticides based on insect viruses and expanded this dramatically into exciting new areas. She is advancing fundamental virology while applying this knowledge in production agriculture in both insect control and in blocking transmission of plant diseases by insects. She clearly is the leader in insect control with recombinant viruses."
Her April 18th seminar promises to zero in on those dratted pea aphids. The more we know about them, the better we can control them.
And the good news is that many of the UC Davis Department of Entomology's seminars will be videotaped and later posted on UCTV.
Pea aphids on a rose leaf. (Photo by Kathy Keatley Garvey)
Pea aphids claim a rose stem. (Photo by Kathy Keatley Garvey)
From moths to medicine...
When distinguished professor Bruce Hammock of the UC Davis Department of Entomology speaks at the department's noonhour seminar tomorrow (Wednesday, April 6) in 122 Briggs Hall, his topic is sure to draw attention.
Hammock's topic: "Moths to Medicine: Epoxide Hydrolase Inhibitors as Analgesic Agents for Neuropathic and Inflammatory Pain." His talk is the second in the department's spring seminar series.
Hammock began his entomological career studying pest management (insect development), and then added a new dimension, pain management (humans), to his research expertise.
He and his lab were recently featured in an article, "Shotgun Approach to Drugs," published in Chemical and Engineering News.
A member of the National Academy of Sciences and a fellow of the Entomological Society of America, Hammock received the UC Davis Faculty Research Lecture Award in 2001 and the Distinguished Teaching Award for Graduate and Professional Teaching in 2008.
Hammock directs the UC Davis Superfund Research Program, which last year received a $13.2 million, five-year competitive renewal grant from the National Institute of Environmental Health Sciences (NIEHS). He also directs the National Institutes of Health Biotechnology Training Program and the NIEHS Combined Analytical Laboratory.
If you can't make it to his talk, not to worry. It will be webcast and then archived on the department's website. There you can link to other entomology-related webcasts recorded since February 2009.
Professor James R. Carey of the Department of Entomology spearheaded the webcasting of the departmental seminars.
Three University of California entomology professors were among the 10 newly elected Fellows of the Entomological Society of America (ESA) honored at the organization's 58th annual meeting, held Dec. 12-15 in San Diego.
Their selection speaks highly of the caliber of UC professors. No more than 10 Fellows are selected for the honor every year from the 6000-member organization, and this year the UC system has three.
They are Bruce Hammock and Thomas Scott of UC Davis and Thomas A. Miller of UC Riverside.
Hammock, a distinguished professor of entomology, studies "inhibitors of epoxide hydrolases as drugs to treat diabetes, inflammation, ischemia and cardiovascular disease," the ESA statement of his work reads. "Compounds from the UC Davis laboratory are in human trials."
That in itself--from bench to bedside--is unique in the annals of entomology.
Hammock, a member of the UC Davis Medical Center's Cancer Center and the National Academy of Sciences, is not only a distinguished professor but a highly sought-after mentor who draws students to his lab from all over the world.
Scott, who directs the UC Mosquito Research Laboratory at Davis, is one of the key "go-to" researchers studying dengue. When he's not in his UC Davis lab, you can usually find him doing research in Peru, Thailand or Mexico. Scott is especially known for his research on mosquito ecology, evolution of mosquito virus interactions, epidemiology of mosquito-borne disease, and evaluation of novel products and strategies for mosquito control and disease prevention.
Scott is a fellow of the American Association for the Advancement of Science and is a past president of the Society for Vector Ecology. He serves as a subject editor for the American Journal of Tropical Medicine and Hygiene. (More on Hammock and Scott on the UC Davis Department of Entomology website.)
ESA officials pointed out that Miller's research "has included structure and function of the insect circulatory system; mode of action of insecticides; insect neuromuscular physiology; physiology, toxicology and behavior of pink bollworm in cotton fields; transgenic insects; and applied symbiosis for crop protection and biopesticides for crop protection. "
Miller's university teaching includes insect physiology, insect toxicology and first year biology. Current projects include control of bush cricket pests of oil palm trees in Papua New Guinea, oversight of field trials of transgenic grapevines with resistance to Pierce's disease, biotechnology for control of desert locust, and regulatory control of insect transgenic technologies.
In 2003 Miller was awarded the Gregor J. Mendel Medal for Research in Biological Sciences by the Czech Academy of Sciences. That's just one of his many honors.
Indeed, the list of honors and accomplishments for these three UC entomologists could easily fill a book!