Her topic is "How Does the Time of Eating Affecting Our Circadian Physiology?" Access this form for the Zoom link.
The abstract: "The integration of circadian and metabolic signals is essential for maintaining robust circadian rhythms and ensuring efficient metabolism and energy use. Using Drosophila as an animal model, we showed that clock-controlled feeding-fasting cycles is strongly correlated to daily protein O-GlcNAcylation rhythms, which may represent a key post-translational mechanism that regulates circadian physiology. Our results could shed light on the benefits of TRE (or intermittent fasting) and the extent to which modern human lifestyles contribute to the current epidemic of metabolic disorders."
The host is her major professor, Joanna Chiu, a molecular geneticist and physiologist, vice chair of the UC Davis Department of Entomology and Nematology and a Chancellor's Fellow. Liu is currently working in the Chiu lab as a postdoctoral fellow.
For her thesis, Liu explored the interplay between circadian clock and metabolism in maintaining animal health using Drosophila melanogaster as a model. Specifically, she investigated the regulation of cellular protein O-GlcNAcylation by circadian clock and metabolic signals. O-GlcNAcylation is a nutrient senstive post-translational modification that can alter the structure and function of thousands of cellular proteins. She is fascinated by how circadian biology can be shaped by multiple factors through complex mechanisms. Her long-term goal is to understand how molecular pathways are coordinated temporally to maintain animal health and wellness.
Liu received her bachelor's degree in biological sciences in 2014 from Beijing Forestry University, China. She was a recipient of a CSC-UC Davis Joint Fellowship.
Coordinating the fall seminars is Cooperative Extension specialist and agricultural entomologist Ian Grettenberg, assistant professor, UC Davis Department of Entomology and Nematology. He may be reached at imgrettenberger@ucdavis for any technical issues.
The seminar takes place from 4:10 to 5 p.m., Wednesday, Oct. 28. Access this site for the Zoom link. Host is Cooperative Extension specialist and agricultural entomologist Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology. He is coordinating the department's fall seminars.
"The research in our lab focuses on understanding how chemical compounds mediate interactions among microbes, plants, herbivores, and herbivore natural enemies," Helms says. "We combine analytical chemistry and behavioral ecology in laboratory and field-based research to investigate how organisms use chemistry to navigate, communicate, and defend themselves. This seminar will discuss some of our ongoing projects examining how plants and insect herbivores use chemical information from their environment to assess their risk of attack and how herbivore natural enemies use such information to find potential prey."
Helms, an assistant professor, holds two degrees from Pepperdine University, Malibu, Calif., both awarded in 2009: a bachelor of science degree in biology and a bachelor of arts degree in biochemistry. She received her doctorate in ecology in 2015 from The Pennsylvania State University, State College, Penn. While in the John Tooker lab, Helms studied the chemical ecology of plant-insect interactions, especially how plants defend themselves against insect herbivores. She investigated how plants use olfactory cues to predict impeding herbivore attacks and the molecular mechanisms involved.
In addition to the general field of chemical ecology, Helms' research interests include plant-insect interactions, tritrophic interactions, belowground chemical ecology, chemical communication, and plant defense.
Her most recent publications:
Helms, A.M., Ray, S., Matulis, N.L.*, Kuzemchak, M.C.*, Grisales, W.*, Tooker, J.F., Ali, J.G. Chemical cues linked to risk: Cues from belowground natural enemies enhance plant defences and influence herbivore behaviour and performance. Functional Ecology. 33, 798-808 (2019). DOI: 10.1111/1365-2435.13297
Acevedo, F.E., Smith, P., Peiffer, M., Helms, A.M., Tooker, J.T., Felton, G.W. Phytohormones in fall armyworm saliva modulate defense responses in plants. Journal of Chemical Ecology. (2019). https://doi.org/10.1007/s10886-019-01079-z
Yip, E.C., Sowers, R.P.*, Helms, A.M., Mescher, M.C., De Moraes, C.M., Tooker, J.F. Tradeoffs between defenses against herbivores in goldenrod (Solidago altissima). Arthropod-Plant Interactions. 13, 279-287 (2019). DOI: 10.1007/s11829-019-09674-3
For any technical issues regarding the seminar, contact Grettenberger at firstname.lastname@example.org.
The article, “Genome-Enabled Insights into the Biology of Thrips as Crop Pests,” is published in the journal BMC Biology. It is the work of 57 scientists on five continents.
“This project represents over eight years of work by at least 17 laboratories across the globe,” said Professor Ullman, a former chair of the entomology department and a fellow of the Entomological Society of America and the American Association for the Advancement of Science. Her laboratory worked closely with project leader and first author Dorith Rotenberg of North Carolina State University. Project scientist Sulley Ben-Mahmoud of the Ullman lab is the paper's third author.
The western flower thrips, Frankliniella occidentalis, causes billions of dollars a year in damage worldwide. Native to Western North America and about the size of a pinhead, the insect feeds on a wide array of food, fiber, and ornamental crops and transmits plant viruses that cause significant economic damage.
“The western flower thrips and the viruses it transmits, including tomato spotted wilt virus, is important to California agriculture, causing serious problems for tomato growers, pepper growers and growers of leafy greens,” Ullman said. The tomato spotted wilt virus infects more than 1000 plant species, ranging from tomatoes, tobacco and peanuts to pansies and chrysanthemums.
“This system has been a central element of my research program for over 30 years," Ullman said, "and I am extremely excited to see this important resource made available as a tool to help us understand and control these important pests.”
In their abstract, the authors wrote that the publication should lead to “understanding the underlying genetic mechanisms of the processes governing thrips pest and vector biology, feeding behaviors, ecology, and insecticide resistance.”
“Attaining a tool to unlock the mysteries of western flower thrips biology and interactions with plant viruses in the family Tospoviridae has been a dream of mine through over 30 years of working on this system,” Ullman commented. “The genome project enabled the discovery of salivary gland-enriched genes in this tiny insect that is now guiding work that Sulley Ben-Mahmoud and I are doing with collaborators Dorith Rotenberg, Joshua Benoit, Samuel Bailey and Priya Rajarapu to identify salivary proteins acting as effectors.”
Rotenberg launched the project in 2011 after delivering a lecture at the 5th Annual Arthropod Genomics Symposium in Kansas City, Mo. “At the time, I was very naïve about what it would take to steward a thrips genome project, but was excited about what a genome sequence could mean for those of us interested in the molecular basis of thrips vector competence and thrips pest biology.”
The team worked with the i5k initiative, an international effort to sequence and analyze 5,000 arthropod genomes. This includes insects, crustaceans, spiders and other creatures with exoskeletons, segmented bodies and pairs of jointed legs.
The Rotenberg-led thrips genome project team first developed an inbred line of thrips. Baylor College of Medicine's Human Genome Sequencing Center sequenced and assembled the genome. The Rotenberg team then verified the location of 10 percent of the nearly 17,000 genes and annotated them to better understand what they do.
The authors report that some genes are associated with the thrips' ability to develop and reproduce, to find plant hosts through taste and smell, to protect against pathogens, and to detoxify plant-produced chemicals and insecticides. The latter is of special interest because thrips are known for rapidly building up resistance to chemicals.
Said Rotenberg: “I discovered over the course of eight years that the thrips genome consortium created something much greater than the sum of its parts. I was fortunate to recruit 17 international groups with expertise in arthropod genomics, evolution and development, thrips vector biology and microbe (and virus)-insect interactions to volunteer their time not only to manually correcting and annotating gene models, but to use expression evidence to explore with me new frontiers in thrips innate immunity, lateral gene transfers of bacterial origin, thrips-plant interactions, thrips development and reproduction. These world-renowned experts helped shape the landscape for contemporary molecular and evolutionary studies of Thysanoptera and in my opinion, as important, helped shape the careers of several undergraduates, grad students and postdoctoral scholars involved in the process. I am excited and proud of what we accomplished together.”
Ben-Mahmoud described the research as “a monumental feat, and I am proud of my contributions to it. I have no doubt that the paper will inform and benefit the studies of many other international insect-vector research groups, not only those who work directly with the western flower thrips.”
The Zoom seminar, open to all interested persons, will take place from 4:10 to 5 p.m. Click here for the form to obtain the Zoom link to connect.
"In this talk, we are going to demonstrate the tripartite interactions between the microbiome, mosquitoes of the genus Aedes and Zika virus that they transmit," she says. Aedes albopictus is also known as the Asian tiger mosquito.
"My research focuses on the tripartite interactions between the microbiome, mosquitoes as vectors and the arboviruses they transmit," Onyango says. "In addition, I am interested in the role the vector-host- pathogen interface plays in enhancing disease severity in the vertebrate host. The goal of my research is to develop innovative control mechanisms both for the vector and pathogens they transmit."
Host is medical entomologist-geneticist Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology. Cooperative Extension specialist and assistant professor Ian Grettenberger coordinates the fall seminars.
"Dr. Maria Onyango works on the biology underlying interactions between arboviruses (Zika virus), vector mosquitoes and the associated microbiome," Attardo said.
Along with seven other scientists, Attardo and Onyango co-authored a research article in the Oct. 2nd edition of Frontiers in Microbiology on"Zika Virus Infection Results in Biochemical Changes Associated With RNA Editing, Inflammatory and Antiviral Responses in Aedes albopictus."
"Rapid and significant range expansion of both the Zika virus (ZIKV) and its Aedes vector species has resulted in the declaration of ZIKV as a global health threat. Successful transmission of ZIKV by its vector requires a complex series of interactions between these entities including the establishment, replication and dissemination of the virus within the mosquito. The metabolic conditions within the mosquito tissues play a critical role in mediating the crucial processes of viral infection and replication and represent targets for prevention of virus transmission. In this study, we carried out a comprehensive metabolomic phenotyping of ZIKV infected and uninfected Ae. albopictus by untargeted analysis of primary metabolites, lipids and biogenic amines. We performed a comparative metabolomic study of infection state with the aim of understanding the biochemical changes resulting from the interaction between the ZIKV and its vector. We have demonstrated that ZIKV infection results in changes to the cellular metabolic environment including a significant enrichment of inosine and pseudo-uridine levels which may be associated with RNA editing activity. In addition, infected mosquitoes demonstrate a hypoglycemic phenotype and show significant increases in the abundance of metabolites such as prostaglandin H2, leukotriene D4 and protoporphyrinogen IX which are associated with antiviral activity. These provide a basis for understanding the biochemical response to ZIKV infection and pathology in the vector. Future mechanistic studies targeting these ZIKV infection responsive metabolites and their associated biosynthetic pathways can provide inroads to identification of mosquito antiviral responses with infection blocking potential."
Onyango holds two degrees from the University of Nairobi, Kenya: a bachelor of science degree in biochemistry and zoology and a master's degree in applied parasitology. She received her doctorate in veterinary entomology from Deakin University and Australian Animal Health Laboratory, Commonwealth Scientific and Industrial Research Organisation (CSIRO), and then completed postdoctoral training at the Yale School of Public Health, Department of Epidemiology of Microbial Diseases.
For any technical issues regarding the seminar, contact Grettenberger at email@example.com
Cooperative Extension agricultural specialist Ian Grettenberger, assistant professor, UC Davis Department of Entomology and Nematology, and his graduate student, Madison "Madi" Hendrick, will discuss the crops, the pests, and the natural enemies or beneficials at a virtual Facebook live session from 11 a.m. to noon, Thursday, Oct 22.
The event, "The Good and the Bad: Insects and Other Arthropods in Agriculture, with a Focus on California Rice and Alfalfa," will be live-streamed on the UC Davis Bohart Museum of Entomology's Facebook page. (Link to Facebook live here). Grettenberger and Hendrick will present short talks and then field questions. No personal Facebook account is required to join the session, which is free and open to the public.
"This is all about the arthropods, both the pests and beneficials that they study in the rice and alfalfa fields," said Tabatha Yang, education and outreach coordinator for the Bohart Museum of Entomology. "Most of the focus is on insects, but tadpole shrimp in rice fields also will be discussed." A virtual family craft activity is also planned.
"I will be discussing some of the insect (or arthropod) problems faced by growers of rice in California and some of the challenges in managing them, Grettenberger said. "In rice, some of the key arthropod pests are tadpole shrimp, which can turn what would have been a lush stand if rice into a poor stand with a lot of floating seedlings. Meanwhile, later in the year, armyworm caterpillars, the larvae of a moth, can chew on rice leaves and destroy plants. I'll discuss some of the ongoing work to better understand and manage these pests."
Grettenberg's fields of expertise include field and vegetable crops; integrated pest management; applied insect ecology, and biological control of pests. (See Spotlight on Ian Grettenberger.) Among his current grants:
- Protection of rice from invertebrate pests
- Insecticide resistant alfalfa weevils in the western United States: Quantifying the scope of resistance and implementing a plan to manage the threat
- Management of key cotton arthropod pests with insecticides and acaricides, a proactive approach to prepare for the invasion of the tomato leafminer (Tuta absoluta) into California
- Detection, biology and control of the exotic Swede midge (Contarinia nasturtii) for California cole crops
- Management of the western spotted and striped cucumber beetle in melon production
- Biological control of the bagrada bug
- Insecticide resistance monitoring and evaluation of efficacy of current chemical tactics for managing aphids and thrips in lettuce
What sparked his interest in entomology? "I had biologist parents, and was drawn into entomology at a pretty young age," Grettenberger said. "I spent plenty of time looking in flowers and turning over logs looking for insects. Once I started thinking about going to graduate school for entomology, I decided to focus on the intersection of agricultural entomology and insect ecology. I wanted to work on applied issues in entomology."
Hendrick, a second-year graduate student in the Grettenberger lab, received her bachelor's degree in iInternational studies at North Carolina State University, and also spent a semester at Nagoya University in Japan (she minored in Japanese).
"I got my start in entomology completely by chance!," Hendrick related. "I needed a science credit and happened to pick a class called 'Insects and People.”' That class really helped me to reframe the way I thought about insects and appreciate what interesting little critters they are. Through that class, I was also able to get a job as an undergraduate assistant in an entomology lab. I worked in a specialty crops lab, where I developed interests in integrated pest management and invasive species. I now study insecticide resistance in the alfalfa weevil, and I'm excited to share what I've learned through this outreach event!"
Grettenberger, Yolo County Farm Advisor Rachael Freeman Long and Madi Hendrick recently wrote a piece in the UC Agricultural and Natural Resources (UC ANR) blog, Alfalfa and Forage News, "A (Virtual )Update on Worms, Weevils an Aphids in Alfalfa."
"This year, the Kearney Research and Extension Center Alfalfa and Forage Field Day went virtual," Grettenberger wrote. "Attendees did not get the chance to look out over lush fields of alfalfa or towering plantings of sorghum, but they get did an update on ongoing work in alfalfa and other forages. Our team put together a rapid-fire video to discuss what are typically the key insect pests in California alfalfa: summer worms, alfalfa weevils, and aphids."
The summer worms in alfalfa include the summer worms: Western yellowstriped armyworm, beet armyworm and alfalfa caterpillar. Another key pest is the alfalfa weevil. The trio also discussed aphids and their natural enemies, including lady beetles, aka ladybugs).
Pests of rice include armyworms, aster leafhoppers, crayfish, rice leafminers, rice seed midges, rice water weevils and tadpole shrimp.
The Bohart Museum, directed by Lynn Kimsey, UC Davis professor of entomology, is located in Room 1124 of the Academic Surge Building on Crocker Lane, UC Davis campus, but is temporarily closed. The museum houses nearly eight million insect specimens; a live "petting zoo" of Madagascar hissing cockroaches, walking sticks and taranatulas; and a gift shop stocked with insect-themed T-shirts, books, posters, jewelry, candy and insect-collecting equipment.
- Alfalfa and Forage News: A (Virtual) Update on Worms, Weevils and Aphids in Alfalfa (By Ian Grettenberger, Rachael Freeman Long and Madi Hendrick, Sept. 20, 2020) (See video on same page)
- Alfalfa and Forage News: Natural Enemies Are Important for Control of the Aphid Complex in Alfalfa--A Case Study (By Ian Grettenberger, Rachael Freeman Long, Daniel Putnam and Rob Wilson, April 7, 2020)
- UC Statewide Integrated Pest Management Program: How to Manage Pests of Alfalfa
- UC Statewide Integrated Pest Management Program: Insects and Other Pests of Rice