- Author: Kathy Keatley Garvey
His topic is "Insularity Effects on Plant-Herbivore Interactions: Searching for Biotic and Abiotic Explanatory Variables to Promote Insular Biodiversity Conservation." The Zoom link:
https://ucdavis.zoom.us/j/95882849672.
UC Davis distinguished professor Richard "Rick" Karban, an international authority on plant-insect communications, is the host.
"For more than six decades, ecologists have hypothesized that insular plant taxa suffer lower levels of
herbivory by insects and mammals, and consequently they have evolved lower defenses or even lost them completely," Moreira says in his abstract. "Although initially this theory was unanimously accepted, recent island-mainland comparisons have shed mixed findings, causing a current vivid debate about insularity effects on plant-herbivore interactions. Inconsistency in patterns reported thus far is basically because studies remain limited in scope both geographically and taxonomically and do not usually consider the multi-trophic context in which plant-herbivore interactions are immersed."
"In this seminar, I will talk about the knowledge gaps and research opportunities on this topic. In particular, further studies should include (1) a broader geographical extent of island-mainland comparisons with site replication within each system and multiple systems (at both regional and global scales), (2) a more comprehensive and integrative assessment of plant defensive phenotypes (multiple traits and their co-expression patterns), (3) measurements ofherbivory by vertebrate and invertebrate herbivores species and guilds, and (4) a consideration of multi-trophic context in which plant-herbivore interactions are embedded, namely how predators and parasitoids respond to insularity and their relative influence on mainland vs. island herbivory and plant defenses." (See more information on his website at https://plantherbivory.weebly.com.)
"Dr. Moreira has done work on various aspects of plant defenses against herbivores," Karban said. "He is best known for papers about the costs of defense, the effects of variable host plants on herbivores and their natural enemies, elevational and latitudinal variation in herbivory, and plant communication that affects herbivory."
Moreira holds a bachelor's degree (2005) in forestry from the University of Santiago and received both his master's degree (2007) and doctorate (2010) from the University of Vigo, Spain. Moreira, who joined the Biological Mission of Galicia in 2015, has served as a senior researcher there since 2021. He was a Fulbright postdoctoral researcher from 2012 to 2014 in the UC Irvine Department of Ecology and Evolutionary Biology.
Emily Meineke, assistant professor of urban landscape entomology, UC Davis Department of Entomology and Nematology, coordinates the department's seminars for the 2022-23 academic year. All 11 seminars will take place both person and virtually at 4:10 p.m. on Wednesdays in Room 122 of Briggs Hall except for the Nov. 9th and Dec. 7th seminars, which will be virtual only, she said. (See list of seminars)
For further information on the seminars or to resolve any technical difficulties with Zoom, contact Meineke at ekmeineke@ucdavis.edu.
- Author: Kathy Keatley Garvey
Cai, of the laboratory of molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the UC Davis Department of Entomology and Nematology, will deliver his seminar both in-person and virtually at 4:10 p.m. in 122 Briggs Hall. The Zoom link:
https://ucdavis.zoom.us/j/95882849672.
Professor Chiu, his major professor, will serve as the host.
"Circadian clocks time daily rhythms inorganismal physiology and behavior to optimize health and fitness," Cai says in his abstract. In Drosophila, phosphorylation regulates time-of-day function of core clock proteins, including the transcriptional
activator CLOCK (CLK). However, it remains unclear whether CLK phosphorylation facilitates the closure of the negative feedback loop. In this study, we demonstrated casein kinase 1 alpha (CK1α) as a CLK kinase and mapped CK1α-dependent CLK phosphorylation sites using mass spectrometry. Our genetic and biochemical analyses revealed that upon CK1α phosphorylation at CLK(S13), CLK occupancy at circadian promoters decreases, thereby sequestering CLK transcriptional activity. Moreover, our results suggest that the transcriptional repressor PERIOD (PER) facilitates CK1α-CLK interaction."
"This study highlights the importance of post-translational regulation of circadian rhythms," Cao noted. "Finally, together with previous studies in fungi and mammals, our results suggest a conserved feature in eukaryotic clocks by which transcriptional repressors recruit CK1s to modulate the activity of transcription activators."
A native of southeast Asia, Cai holds two degrees from China Agricultural University, Beijing: a bachelor of science degree (2014) in plant protection and a master's degree in entomology (2016).
What sparked his interest in entomology? "The insect world presented to me the diversity of species when I was a kid," he related. "Since then, I have wondered about the origin and evolution of species. I was lucky to cultivate my interest as an undergrad and then a master student in Chinese Agricultural University. As a PhD student in the Department of Entomology and Nematology at UC Davis, this interest expanded to the cellular and molecular mechanisms of evolution and adaptation. Upon my graduation in summer 2022, I continued my postdoctoral research in the Chiu Lab. I hope this will prepare me to become a professor in biological sciences."
Cai completed an International Chronobiology Summer School (virtual) in 2020 and a UC Davis Comprehensive Course in Flow Cytometry in 2019. His publications include:
- Cai YD*, Joshi R*, Xia Y, Chiu JC, Emery P (2022) PERIOD phosphoclusters control temperature compensation of the Drosophila circadian clock, Frontiers in Physiology. 13: 888262.
- Cai YD, Sotelo SH, Jackson K, Chiu JC (2022) Assaying circadian locomotor activity rhythm in Drosophila, in “Circadian Rhythms” in NeuroMethods series. ed. M. Hatori, T. Hirota, and S. Panda. Springer Nature, Switzerland.
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Cai Y.D., Y. Xue, C. Truong, J. Del-Carmen Li, C. Ochoa, J.T. Vanselow, K.A. Murphy, Y.H. Li, X. Liu, B.L. Kunimoto, H. Zheng, C. Zhao, Y. Zhang, A. Schlosser, J.C. Chiu (2021). CK2 inhibits TIMELESS nuclear export and modulates CLOCK transcriptional activity to regulate circadian rhythms. Current Biology 31(3): 502-514.
- Cai, Y.D., J.C. Chiu (2021). Timeless in animal circadian clocks and beyond. FEBS Journal (Online ahead of print). doi: 10.1111/febs.16253.
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Abrieux, A., Y. Xue, Y. Cai, K.M. Lewald, H.N. Nguyen, Y. Zhang, J.C. Chiu. (2020). EYES ABSENT and TIMELESS integrate photoperiodic and temperature cues to regulate seasonal physiology in Drosophila. Proceedings of the National Academy of Sciences. U.S.A. 117(26): 15293-15304.
Active in academics, Cai served as a guest lecturer for Entomology 102 on the "Insect Nervous System" and for Entomology 10 on "Insect Circadian Rhythm." He also served as a teaching assistant for a number of UC Davis classes, including Applications, Values, and Ethics in Animal Research; Insect Physiology; Introduction to Biology: Ecology and Evolution; Introduction to Biology: Cell Functions; and Calculus for Biology and Medicine. In addition, he has assisted at Bohart Museum of Entomology open houses and at science program provided by Peregrine School, Davis.
Honored with a number of awards, Cai received a 2021 Chinese Government Award for Outstanding Self-Finance Students Abroad; a 2021 UC Davis Entomology W. Harry Lange, Jr. Memorial Travel Fund; 2021 UC Davis Marv Kinsey Scholarship; a 2020 Boroughs Welcome Fund Society for Research on Biological Rhythms (SRBR) Excellence Award; a 2020 UC Davis Sean and Anne Duffey and Hugh and Geraldine Dingle Research Fellowship; a 2019 UC Davis McBeth Memorial Scholarship; and a 2018 and 2017 UC Davis Henry A. Jastro Graduate Research Awards, among others.
Cai was a member of the Entomology Band, comprised of seven UC Davis graduate students who performed at Briggs Hall during the 2018 campuswide Picnic Day celebration. Cao, the drummer, dressed as a fruit fly. Entomology Today, a publication of the Entomological Society of America, featured the band in a June 2018 edition.
Emily Meineke, assistant professor of urban landscape entomology, UC Davis Department of Entomology and Nematology, coordinates the department's seminars for the 2022-23 academic year. All 11 seminars will take place both person and virtually at 4:10 p.m. on Wednesdays in Room 122 of Briggs Hall except for the Nov. 9th and Dec. 7th seminars, which will be virtual only, she said. (See list of seminars)
For further information on the seminars or to resolve any technical difficulties with Zoom, contact Meineke at ekmeineke@ucdavis.edu.
- Author: Kathy Keatley Garvey
Filipa Rijo-Ferreira, a UC Berkeley School of Public Health (BPH) assistant professor who specializes in parasitology and circadian rhythms, will present a UC Davis Department of Entomology and Nematology seminar at 4:10 p.m., Wednesday, Oct. 19 on "Circadian Rhythms in Parasitic Diseases" in 122 Briggs Hall.
Her seminar also will be virtual. The Zoom link is https://ucdavis.zoom.us/j/95882849672. Host is molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the UC Davis Department of Entomology and Nematology.
"Malaria's main symptom is the periodic fevers experienced by patients, fevers that ‘come and go' at certain times of the day and are a consequence of synchronized parasite rhythms," Rijo-Ferreira says in her abstract. "In humans, circadian clocks regulate multiple aspects of physiology, including sleep-wake cycles, metabolism, and immune defense. Circadian biology leads to body rhythms experienced by the pathogens that infect humans. In addition to sensing host rhythms, we recently discovered that parasites which cause devastating health burdens such as malaria and sleeping sickness diseases also have their own intrinsic clocks. The clocks of parasites regulate core biological functions from metabolism to the cell cycle, and the discovery of the existence of their clocks serves as an opportunity to access the molecular mechanisms regulating their rhythmic biology."
Rijo-Ferreira, trained in infectious diseases and neuroscience, joined the UC Berkeley faculty in January 2022. A native of Lisbon, Portugal, she holds a bachelor's degree in molecular and cellular biology from Nova University of Lisbon, and her master's degree in 2009 in molecular genetics and biomedicine from Imperial College, London. She received her doctorate in 2016 at the University of Porto, Portugal, where she completed her studies in basic and applied biology, molecular parasitology, and neuroscience. Postdoctoral training followed at the University of Texas Southwestern Medical Center, Dallas.
"Our lab is interested in parasitic infections and we study them under the lenses of time of day," she wrote on her lab website. "Our rhythmic world has been a driving force for organisms to evolve a molecular clock to anticipate such daily rhythms. Similarly, our own circadian biology leads to physiological rhythms that parasites experience.We study the single-celled parasites Plasmodium spp. that causes malaria, and Trypanosoma brucei that causes sleeping sickness. We employ technical approaches spanning from next-generation sequencing, to cellular and behavioral assays to investigate the interactions of these parasites with their hosts.Our work seeks to understand how circadian rhythms modulate host-parasite-vector interactions and identify opportunities in their rhythmic biology to treat parasitic infections
In an interview with BPH staff writer Eliza Partika, published in February 2022, she commented: "I am fascinated about our day and night cycles and how organisms evolved to anticipate them. I find it incredible that parasites, such as the ones that cause malaria, show a coordinated rhythmic pattern themselves, which underlies periodic fevers in infected individuals. Our research is aimed at understanding how this phenomenon is regulated molecularly, and how we can disrupt these rhythmic patterns to offset the infection."
"At BPH, we aim to set up a framework where we can explore the relationships between parasites, hosts, and the mosquitoes that serve as the vector of disease transmission, based on the time of day," Rijo-Ferreira related. "We hypothesize that the circadian rhythms of these three organisms need to be aligned in order for the parasite to cause an efficient infection. In fact, when rhythms are misaligned, there is a reduction in parasite levels. Thus, identifying the molecular players from host, parasite, and mosquito is essential to understanding this phenomenon and creating alternative strategies to manage deadly infections like malaria and sleeping sickness."
Rijo-Ferreira said she seeks to "bring to the attention the circadian aspect of infectious diseases and bring awareness of the potential benefits of time of day vaccination and drug treatment."
Emily Meineke, assistant professor of urban landscape entomology, UC Davis Department of Entomology and Nematology, coordinates the department's seminars for the 2022-23 academic year. All 11 seminars will take place both person and virtually at 4:10 p.m. on Wednesdays in Room 122 of Briggs Hall except for the Nov. 9th and Dec. 7th seminars, which will be virtual only, she said. (See list of seminars)
For further information on the seminars or to resolve any technical difficulties with Zoom, contact Meineke at ekmeineke@ucdavis.edu.
/span>- Author: Kathy Keatley Garvey
Their work, “Insect Herbivory Within Modern Forests Is Greater than Fossil Localities,” appears in the Oct. 10th edition of the Proceedings of the National Academy of Sciences (PNAS). The first-of-its-kind study compares insect herbivore damage of modern-era plants with that of fossilized leaves dating as far back as 67 million years ago.
“Our work bridges the gap between those who use fossils to study plant-insect interactions over deep time and those who study such interactions in a modern context with fresh leaf material,” said lead researcher and ecologist Lauren Azevedo-Schmidt, formerly of the Department of Biology, University of Wyoming and now a postdoctoral research associate with the Climate Change Institute, University of Maine. “The difference in insect damage between the modern era and the fossilized record is striking.”
No stranger to UC Davis, Currano presented a UC Davis Department of Entomology and Nematology seminar, hosted by Meineke, on "Ancient Bug-Bitten Leaves Reveal the Impacts of Climate and Plant Nutrients on Insect Herbivores" on April 28, 2021.
“Plants and insects are the most diverse lineages on earth, but their interactions in the face of climate and other global changes are poorly understood…despite insect declines, insect damage to plants is elevated in the modern era compared with other time periods represented in the fossil record,” they wrote. “Plants today are experiencing unprecedented levels of insect herbivory, with unknown consequences for plant fitness and evolution.”
The scientists presented estimates for damage frequencies and diversities on fossil leaves from the Late Cretaceous (66.8 million years ago) through the Pleistocene (2.06 million years ago) and compared these estimates with recent (post-1955) leaves collected via paleobotanical methods from three modern ecosystems, including Harvest Forest, a 3000-acre ecological research area in managed by Harvard University and located in Petersham, Mass. The site, in operation since 1907, is one of North America's oldest managed forests.
Other ecosystems: the Smithsonian Environmental Research Center (SERC) of Chesapeake Bay, a 2,650-acre campus spanning forests, wetlands, marshes and 15 miles of protected shoreline, and the 3953-acre La Selva Research Station, Costa Rica, a private forest reserve.
The scientists advocate more research to determine the precise causes of increased insect damage to plants, but related that a “warming climate, urbanization and introduction of invasive species likely have had a major impact.”
“We hypothesize that humans have influenced (insect) damage frequencies and diversities within modern forests, with the most human impact occurring after the Industrial Revolution,” the researchers wrote. “Consistent with this hypothesis, herbarium specimens from the early 2000s were 23 percent more likely to have insect damage than specimens collected in the early 1900s, a pattern that has been linked to climate warming.”
“This research suggests that the strength of human influence on plant-insect interactions is not controlled by climate change alone but, rather, the way in which humans interact with the terrestrial landscape,” the researchers concluded.
Meineke, who joined the UC Davis faculty in 2020, served as a postdoctoral fellow at Harvard University Herbaria from 2016 to 2019, including a National Science Foundation-sponsored fellowship there in 2017. She holds a doctorate in entomology from North Carolina State University (2016), Raleigh, where she wrote her dissertation on “Understanding the Consequences of Urban Warming for Street Trees and Their Pests.”
Meineke helped spearhead the newly created Harvard Museum of Natural History's “In Search of Thoreau's Flowers: An Exploration of Change and Loss," hailed as an examination of the natural world and climate change at the intersections of science, art and history. The exhibit opened to the public May 14, 2022.
- Author: Kathy Keatley Garvey
His seminar, set for 4:10 p.m. in 122 Briggs Hall, will focus on Diabrotica (cornroot worms). It will be both in-person and via Zoom. The Zoom link: https://ucdavis.zoom.us/j/
Host is molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the Department of Entomology and Nematology.
"Although they are largely studied because of their economic significance, agricultural pests can be useful model systems to study fundamental biology," Miller says in his abstract. "The beetle genus Diabrotica ("corn rootworms") includes species with generalist and specialist feeding habits that overlap on a common host plant, maize. This makes the genus an excellent system to study the adaptations of insect herbivores with differing host ranges to a common set of plant defenses. A long-standing area of interest in my lab is the adaptations of generalist and specialist Diabrotica species to the maize defensive compound DIMBOA."
Research in the Miller lab focuses on the population genetics and evolution of herbivorous insects. "We mostly study species that are pests of agriculture," he says on his website. "Key areas of interest include: adaptation by insect pests to the technologies intended to control them, including genetically-modified crops and pesticides; the interactions of specialist and generalist herbivores to plant defenses; dispersal and movement of insects and the genes they carry."
Miller holds a bachelor's degree and a doctorate from the University of Birmingham. His most recent publication:
- Rault LC, Siegfried BD, Gassmann AJ, Wang H, Brewer GJ, Miller NJ( 2018). Investigation of Cry3Bb1 resistance and intoxication in western corn rootworm by RNA sequencing. J Appl Entomol. 2018. 1–16. DOI: 10.1111/jen.12502
Emily Meineke, assistant professor of urban landscape entomology, UC Davis Department of Entomology and Nematology, coordinates the department's seminars for the 2022-23 academic year. All 11 seminars will take place both person and virtually at 4:10 p.m. on Wednesdays in Room 122 of Briggs Hall except for the Nov. 9th and Dec. 7th seminars, which will be virtual only, she said. (See list of seminars)
For further information on the seminars or technical difficulties with Zoom, contact Meineke at ekmeineke@ucdavis.edu.