Oct. 31, 2012
The seminar will take place from 12:10 to 1 a.m. in Room 1022 of the Life Sciences Building. Host is George Kamita of the Bruce Hammock lab.
Ohkawa says in his abstract:
“Baculoviruses (named for their shape-baculum being Latin for 'rod') are insect viruses that have been studied as potential pest control agents, as they infect caterpillars (the larval stage of butterflies and moths), many of which are agricultural pests. These viruses have DNA genomes, and they replicate in the cell nucleus. Autographa californica M nucleopolyhedrovirus (AcMNPV) is the most well-studied baculovirus. One of the unique features of AcMNPV infection is that viral particles, upon entry into cells, uses host actin for transport, assembling actin filaments and using the force of this assembly, generating actin 'comet tails' for propulsion through the cell cytoplasm.”
“Another unique, and quite dramatic feature of AcMNPV infection is that the virus causes an accumulation of actin in the cell nucleus. And when the virus begins to replicate, generating new progeny, a massive accumulation of actin filaments can be seen within the nucleus- a very abnormal phenomenon. Our recent work has demonstrated that newly synthesized viral particles also assemble actin for transport, and this actin assembly is critical for how the virus can escape through the nuclear membrane, and how the virus moves through the cytoplasm in order to escape the cell.”
Of his research, Ohkawa says: “The goal of my research is to define the mechanisms by which a baculovirus, Autographa californica M Nucleopolyhedrovirus (AcMNPV) manipulates the host cell actin cytoskeleton throughout the viral replication cycle. This work is carried out at the genetic level, with the manipulation of the AcMNPV viral genome, including gene deletions, gene tagging, and the introduction of fluorescent protein constructs, as well as at the cellular level where microscopic examination of infected cells allows elucidation of how the virus affects cellular actin. Specifically, I have used fluorescence to label viral nucleocapsids, which when infected into cultured insect cells expressing fluorescent actin, have revealed that the virus uses actin-based motility for transit to the nucleus.”
“My ongoing research includes studying how AcMNPV uses actin-based motility for pre-replication transit from cell-to-cell, as well as determining the function of nuclear-localized actin and actin-based motility during the post-replication/egress stage.”
Ohkawa received his doctorate in biochemistry and molecular biology in 1997 from UC Davis, where he was housed in the lab of Susumu Maeda in the Department of Entomology. “There I learned about baculovirus molecular biology and the genetic manipulation of the viral genome,” he said.
Following graduation, he began post-doctoral research in the lab of Loy Volkman at UC Berkeley, where he became acquainted with the role of actin during viral replication. “This introduction into cell biology was strengthened by a collaboration with the lab of Matt Welch, also at UC Berkeley. Upon Loy Volkman's retirement, I moved to the Welch lab, where I began my current projects, which are more intensively cell biology-based. Our synthesis of molecular virology and cell biology have led to unprecedented advances in examining viral mechanisms of transport, and the viral usage of the cell actin cytoskeleton.”
Ohkawa has occupied his current position at UC Berkeley since 2006. He is a member of the American Society for Virology and the American Association for Cell Biology.
Among his most recent peer-reviewed publications:
- Misra S, Buratowski RM, Ohkawa T, and Rio DC 1993. Cytotype control of Drosophila P element transposition: genomic position determines maternal repression, Genetics. 135, 785-800.
- Ohkawa T, McCutchen BF, Hanzlik TN, Kamita SG, Sasagawa H, Choudary PV, Hammock BD, and Maeda S, 1994. Stage independent insecticidal effects of a recombinant baculovirus on Bombyx mori larvae. Appl. Entomol. Zool. 29: 442-448.
- Ohkawa T, Majima K, and Maeda S, 1994. A cysteine protease encoded by the baculovirus Bombyx mori nuclear polyhedrosis virus. Journal of Virology 68: 6619-6625.
- Ohkawa T, and Volkman LE, 1999. Nuclear F-Actin is Required for AcMNPV Nucleocapsid Morphogenesis. Virology 264: 1-4.
- Hom LG, Ohkawa T, Trudeau D, and Volkman LE, 2002. Autographa californica M Nucleopolyhedrovirus ProV-CATH is Activated during Infected Cell Death. Virology 296: 212-218.
- Ohkawa T, Rowe AR, and Volkman LE, 2002. Identification of Six Autographa californica Multicapsid Nucleopolyhedrovirus Early Genes That Mediate Nuclear Localization of G-Actin. Journal of Virology 76: 12281-12289.
- Zhang J, Ohkawa T, Washburn JO, and Volkman LE, 2005. Effects of Ac150 on virulence and pathogenesis of Autographa californica multiple nucleopolyhedrovirus in noctuid hosts. Journal of General Virology 86: 1619-1627.
- Ohkawa T, Washburn JO, Sitapara R, Sid E, and Volkman LE, 2005. Specific binding of Autographa californica M nucleopolyhedrovirus occlusion-derived virus to midgut cells of Heliothis virescens larvae is mediated by products of pif genes Ac119 and Ac022 but not by Ac115. Journal of Virology 79: 15258-15264.
- Goley ED, Ohkawa T, Mancuso J, Woodruff JB, D'Alessio JA, Cande WZ, Volkman LE, and Welch MD, 2006. Dynamic nuclear actin assembly by Arp2/3 complex and a baculovirus WASP-like protein. Science 314: 464-467.
- Ohkawa T, Volkman LE, and Welch MD, 2010. Actin-based motility drives baculovirus transit to the nucleus and cell surface. Journal of Cell Biology 190: 187-195.
Seminar co-chairs are assistant professors Joanna Chiu and Brian Johnson. Under the coordination of James R. Carey, professor of entomology, Ohkawa's seminar will be videotaped and posted at a later date on UCTV. (See the index of previous Department of Entomology seminars posted on UCTV.)
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Oct. 25, 2012
"Aedes aegypti is an important vector of human diseases, such as dengue fever and yellow fever," he says in his abstract. "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 Ae aegypti. The high insecticidal activity and the low toxicity to other organisms 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."
"The 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."
Professor Gill’s laboratory has two principal research foci. "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 Department of Entomology faculty at UC Riverside in 1983. He helped establish the Department of Cell Biology and Neuroscience and also served as chair. Currently is the co-editor of the 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.
Assistant professors Joanna Chiu and Brian Johnson are organizing the seminars. All the noonhour sessions are being recorded for UCTV. (See the index of previous Department of Entomology seminars posted on UCTV.)
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Oct. 22, 2012
This is part of the Entomology 1 and UC Davis Art/Science Fusion Program course taught by Diane Ullman and Donna Billick, co-founders of the UC Davis Art/Science Fusion Program.
“We welcome all members of the UC Davis community to participate, especially those in Insect Science, Design and Techno-Cultural Studies,” said Brady, the creator of the Insect News Network.
“I will be stepping beyond the standard boundaries of insect science into the emerging, unexplored territory of cultural entomology,” Brady said. “Since over 50 percent of the world's population now lives in cities-- and more than 250 million Americans live in or around urban areas -- a bold new interpretation of the human-insect interdependence is essential. There is ample evidence that this is already in the works: cultural entomology examines the microcosm in over 60 fields of human endeavor not traditionally examined by insect science.
“In this talk I will offer vivid examples in architecture, tattoos, grafitti, video games, digital design, media, fashion, and urban tribes,” he said, adding that he will frame the discussion “in a contemporary context for the student populace, citing entertainment celebrities, blockbuster video games and films, and cultural luminaries who are re-defining our concepts about life on Earth.”
“I set the stage for the catalysis of an urban re-evolution regarding Insects, spiders and other organisms that run the planet. We will discuss practical, compelling and sublime examples of the influence of insects, and the origins of the insect tribe.”
The UC Davis Art/Science Fusion Program, founded in 2006, is a pioneering program in the use of an art-science fusion paradigm in undergraduate education and community outreach.
Ullman, professor and former chair of the UC Davis Department of Entomology, is the associate dean for undergraduate academic programs in the College of Agricultural and Environmental Sciences.
Billick, a self-described “rock artist,” is an alumna of UC Davis (bachelor of science degree in genetics in 1973 and her master’s degree in fine arts in 1977).
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Oct. 22, 2012
Dadala, an associate professor in the Department of Sericulture in Tirupati, India, was notified of the honor Oct. 18. She is expected to begin her eight-month Fulbright-Nehru-2013 senior research fellowship in August.
“This is a highly competitive and a huge honor,” said Hammock, a distinguished professor of entomology. "We are thrilled to have her back as part of the laboratory family."
Specifically, Dadala is researching genes for insect specific enzymes that metabolize the juvenile hormone (JH) and how they can be expressed to develop recombinant baculovirus.
During the 35-minute oral interview, she was asked: “Baculovirus expression can be done in India, too, in many labs. How do you justify?”
“Yes, it’s true,” she told them, “but beyond baculovirus expression, I'm looking for the able mentorship of Professor Bruce Hammock, to study and explore the endogenous role of JHEH (Juvenile Hormone Epoxide Hydrolase) protein which can be further brought forth as a biopesticide.”
“They were well pleased with the answer,” Dadala told Hammock in an email.
“Further, looking at my application and your consent letter, one of the board members said ‘Your mentor seems to be a very big guy in the United States.”
Dadala told them “very true. It’s my privilege to get his consent and learn from him.”
Dadala, a researcher in the Hammock lab from July 13, 2007 through June 8, 2008, is the lead author of Integrated Insect Pest Management-Physiological and Molecular Approaches, with Sreedevi Kolla. Of the 148-page book, published by VDM Publishing, they wrote: “The agricultural land is becoming a scarce resource with increased pressure of population wherein ways to enhance the crop productivity needs to be strengthened. One of the focuses is to curb the crop losses due to insect pests in a sustainable manner. The alarming and detrimental effects of chemical pesticides on environment and non target organisms, integrated pest management has been evolved with viable, benign and ecofriendly strategies. As juvenile hormone (JH) plays an important role in insect's physiology and reproduction, the systems (metamorphosis, moulting and reproduction) related to JH are potential targets of pest management. Genes for insect specific enzymes that metabolize JH can be expressed to develop recombinant baculovirus, which can disrupt physiology and in turn becomes detrimental to the pest itself. Further, the role of JH binding protein, Ecdysone receptor proteins are also explored for biocontrol strategies. Development of novel recombinant baculovirus biopesticide and its applicability are discussed.”
She is also a co-author of “The Role of a- and b-hydrolase Fold Enzymes as Biopesticides in Pest Management” published last year in the Journal of Biopesticides. It is online at
http://www.jbiopest.com/users/LW8/efiles/Vol_5_0_233_238F.pdf
Hammock, who has a joint appointment with the UC Davis Comprehensive Cancer Center, directs the campuswide Superfund Research Program, the National Institutes of Health Biotechnology Training Program and the 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 UC Davis Faculty Research Lecture Award in 2001 and the Distinguished Teaching Award for Graduate and Professional Teaching in 2008.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Oct. 15, 2012
The public event, themed “The Bounty of Pollination: More Than Just Honey,” is set from 1 to 5:30 p.m., Saturday, Oct. 27 in the RMI’s Silverado Vineyards Sensory Theatre, UC Davis campus.
The event will feature award-winning cinematographer, director and producer Louie Schwartzberg whose film “The Beauty of Pollination” has resulted in more than 23 million views on YouTube. Schwartzberg will give his presentation at 2:50 p.m. Another key speaker is pollination ecologist Neal Williams, assistant professor, UC Davis Department of Entomology, who will discuss “Integrated Pollination Strategies: Managed and Wild Bees for a Sustainable Future” at 3:30 p.m.
Amina Harris, executive director of the RMI Honey and Pollination Center and owner of Z Specialty Food, Woodland, will speak on “Honey Tastings Across America” from 1:15 to 1:45 p.m.
Also on the agenda:
--Victoria Wojcik, associate program manager of the Pollinator Partnership, based in San Francisco, will discuss “The World of Pollinators” from 1:45 to 2:15 p.m.
--Julie Loke, teaching kitchen educator at Davis Co-Op, “Varietal Honeys—Blending the Flavors in the Kitchen” from 4:05 to 4:35 p.m.
RMI executive director Clare Hasler-Lewis and Edwin Lewis, professor and vice chair of the UC Davis Department of Entomology, will welcome the crowd. Lewis and Andy Waterhouse, professor of enology in the Department of Viticulture and Enology, are the newly selected faculty chairs of the Honey and Pollination Center.
Following the program, a reception at 4:35 p.m. will include honey wine (mead) tasting; varietal honey tasting; the second annual “Best Honey” competition; a bee observation hive from the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis; displays from Queen Sheba Winery, Woodland; Sky River Meadery, Redmond, Wash., and Z Specialty Foods; and UC Davis displays from Shields Library, Bohart Museum of Entomology, and the UC Davis Bookstore
The organizers promise “an afternoon of lively discussions, unique tastings and interesting displays on the science behind honey and the non-honey bee pollinators.”
Tickets are $60 per person. Friends of RMI, faculty, staff and students will be admitted for $50. For online registration and other information, see the RMI website.
For the honey competition, any beekeeper can drop off a jar of honey, with a business card and a summary of the honey to the RMI office on Wednesday, Oct. 24. There is no charge to enter the honey competition, said RMI event coordinator Tracy Dickinson
RMI executive director Clare Hasler-Lewis said the newly established Honey and Pollination, was approved earlier this year by the College of Agricultural and Environmental Sciences. The vision is to “make UC Davis the nation’s leading authority on honey, honey bees and pollination by combining the resources and expertise of RMI and the Department of Entomology’s Harry H. Laidlaw Jr. Honey Bee Research Facility.”
The center’s mission is “to showcase the importance of honey and pollination to the well-being of the citizens of California. The center will spearhead and nucleate efforts to gain support and assembly teams for research, education and outreach programs for various stakeholder groups including the beekeeping industry, agricultural interests who depend on bee pollination, backyard beekeepers and the food industry."
The goals:
• Expand research and education concerning nutrition, health, quality and appreciation of honey
• Develop useful information for California’s agricultural bounty that depends on insect pollination
• Help the honey industry establish labeling guidelines to guarantee pure and unadulterated varietal honey
• Coordinate a multidisciplinary team of experts in honey production, pollination and bee health
• Promote the use of locally procured honey in the home, food industry and restaurants.
For more information and registration see the website at http://rmi.ucdavis.edu/bounty-of-pollination. The contact person is Kim Bannister at kbannister@ucdavis.edu.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
