- Author: Kathy Keatley Garvey
That's true for assistant professor Katie Thompson-Peer of the Department of Developmental and Cell Biology, UC Irvine, who will speak on "Cellular Mechanisms of Dendrite Regeneration after Neuron Injury” at the UC Davis Department of Entomology and Nematology seminar on Wednesday, May 24.
She uses the larvae and adult fruit fly, Drosophila melanogaster, as a model to study dendrite regeneration.
Thompson-Peer will present her seminar at 4:10 p.m. in Room 122, Briggs Hall. Her seminar also will be virtual. The Zoom link: https://ucdavis.zoom.us/j/95882849672
Her abstract: “Neurons have two types of cellular projections, that are essential for how they function in circuits: they have a single axon and a highly branched network of dendrites. These dendrites are the cellular structures that allow neurons to receive input from the environment or from other neurons. While much is known about how axons respond to injury, almost nothing is known about how neurons respond to dendrite injury. We have found that after dendrite injury, peripheral nervous system neurons are able to mount a reliable, reproducible process of dendrite regeneration. In this talk, I present our recent work to determine how neurons detect injury to their dendrites, using the larvae and adult fruit fly Drosophila melanogaster as a model to study dendrite regeneration.”
Thompson-Peer, who joined UC Irvine in April 2019, received her bachelor's degree in biology from the University of Pennsylvania, and then followed with a two-year stint at the Johns Hopkins University with Alex Kolodkin. She earned her doctorate from Harvard University, working with Josh Kaplan, and was a postdoctoral fellow with Yuh-Nung and Lily Jan at UC San Francisco and the Howard Hughes Medical Institute. Her postdoctoral work drew financial support from the National Institute of Neurological Disorders and Stroke F32 and K99/R00 fellowships, as well as a UC Office of the President's Postdoctoral Fellowship.
The Thompson-Peer lab explores how neurons recover from injury in vivo, and how this process is similar to and different from normal development. (See her work showcased on YouTube)
"At the most fundamental level, a neuron receives information along dendrites, and sends information down an axon to synaptic contacts," she writes on her website. "Dendrites can be injured by traumatic brain injury, stroke, and many forms of neurodegeneration, yet while the factors that control axon regeneration after injury have been extensively studied, we know almost nothing about dendrite regeneration. Our long-term research goal is to understand the cellular mechanisms of dendrite regeneration after injury."
"Our previous work found that the sensory neurons in the fruit fly Drosophila peripheral nervous system exhibit robust regeneration of dendrites after injury and used this system to explore central features of dendrite regeneration in developing animals, young adults, and aging adults. We have observed that after injury, neurons regrow dendrites that recreate some features of uninjured dendrites, but are unable to reconstruct an entire arbor that perfectly mimics an uninjured neuron. Moreover, there are mechanistic differences between the outgrowth of uninjured neurons versus the regeneration of dendrites after injury: dendrite regeneration is uniquely dependent on neuronal activity, ignores cues that constrain and pattern normal dendrite outgrowth, and confronts a mature tissue environment that is different from what a developing neuron would encounter. These challenges are significantly exacerbated when neurons in aging animals attempt to recover from injury."
Department seminar coordinator is urban landscape entomologist Emily Meineke, assistant professor. For technical issues regarding Zoom connections, she may be reached at ekmeineke@ucdavis.edu. (See complete list of spring seminars.)

- Author: Kathy Keatley Garvey
So says molecular biologist Wanhe Li, an assistant professor at Texas A&M and a Cancer Prevention and Research Institute of Texas (CPRIT) Scholar, who will present a seminar, hosted by the UC Davis Department of Entomology and Nematology, on Wednesday, Nov. 2
Li will discuss "How Time Flies During Lockdown?--Mechanisms Underlying Chronic Social Isolation-induced Sleep Loss in Drosophila" at her in-person and virtual seminar at 4:10 p.m., in 122 Briggs Hall. The Zoom link: https://ucdavis.zoom.us/j/95882849672.
Introducing her will be molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the UC Davis Department of Entomology and Nematology.
"Chronic social isolation and loneliness have profound impacts on public health," Li says in her abstract. "Though experimental manipulations are widely applied to studying sleep/wakefulness and circadian regulation in animal models, how normal sleep is perturbed by social isolation and chronic stress is largely unknown. We previously reported that chronically isolated animals exhibit sleep-loss accompanied by over-consumption of food. The observed behavioral changes induced by chronic social isolation stress is linked to neural activities in specific neural circuits in the Drosophila brain."
"These results," she continued, "resonate with anecdotal findings of loneliness-associated sleep difficulties and hyperphagia in humans, and present a mechanistic link between chronic social isolation, metabolism, and sleep, addressing a long-standing call for animal models focused on loneliness. Future work built upon this model will help us understand the perception of social isolation and other emotional states, the regulation of sleep/wakefulness, and the regulation of metabolism at the intersection of genetics, biological timing, and neurobiology."
Science Daily, in its Aug. 18, 2021 edition, reported on her research (co-authored by eight colleagues): "COVID-19 lockdowns scrambled sleep schedules and stretched waistlines. One culprit may be social isolation itself. Scientists have found that lone fruit flies quarantined in test tubes sleep too little and eat too much after only about one week of social isolation, according to a new study published in Nature. The findings, which describe how chronic separation from the group leads to changes in gene expression, neural activity, and behavior in flies, provide one of the first robust animal models for studying the body's biological reaction to loneliness."
Li, who holds a bachelor's degree in biological sciences (2004) from Nankai University, Tianjin, China, received her doctorate in molecular and cellular biology from Stony Brook University in 2011 through a joint program with Cold Spring Harbor Laboratory, Laurel Hollow, N.Y. She served as a postdoctoral associate and research associate,The Rockefeller University, New York City.
Some of her latest publications:
- Li, W, Keene, AC. Flies sense the world while sleeping. Nature. 2021;598 (7881):423-424. doi: 10.1038/d41586-021-02441-6. PubMed PMID:34588643 .
- Li, W, Wang, Z, Syed, S, Lyu, C, Lincoln, S, O'Neil, J et al.. Chronic social isolation signals starvation and reduces sleep in Drosophila. Nature. 2021;597 (7875):239-244. doi: 10.1038/s41586-021-03837-0. PubMed PMID:34408325 PubMed Central PMC8429171.
- Ahmad, M, Li, W, Top, D. Integration of Circadian Clock Information in the Drosophila Circadian Neuronal Network. Journal of Biological Rhythms. 2021;36 (3):203-220. doi: 10.1177/0748730421993953. PubMed PMID:33641476 PubMed Central PMC8114447.
- Garaulet, DL, Sun, K, Li, W, Wen, J, Panzarino, AM, O'Neil, JL et al.. miR-124 Regulates Diverse Aspects of Rhythmic Behavior in Drosophila. Journal of Neuroscience, 2016;36 (12):3414-21. doi: 10.1523/JNEUROSCI.3287-15.2016. PubMed PMID:27013671 PubMed Central PMC4804003.
- Shuai, Y, Hirokawa, A, Ai, Y, Zhang, M, Li, W, Zhong, Y et al.. Dissecting neural pathways for forgetting in Drosophila olfactory aversive memory. Proceedings of the National Academy of Sciences U S A. 2015;112 (48):E6663-72. doi: 10.1073/pnas.1512792112. PubMed PMID:26627257 PubMed Central PMC4672816.
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
Nematologist and plant pathologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology and coordinator of the department's seminars for the 2021-22 academic year, has announced the list of fall quarter seminars, which begin Sept. 29 and conclude Dec. 1.
All will be held at 4 p.m. on Wednesdays, Pacific Time, and will include both in-person and virtual seminars.
"We we have an exciting list of seminars that includes both national and international speakers," Siddique said.
The in-person seminars will take place in Room 122 of Briggs Hall, located off Kleiber Hall Drive. These seminars will be recorded for later viewing.
Three of the seminars will be virtual. "Virtual seminars will be accomplished using the Zoom meeting software package," Siddique related. A Zoom link will be provided a week before the seminar.
First on tap will be the exit seminar of doctoral candidate Hanna Kahl of the lab of UC Davis distinguished professor Jay Rosenheim. She will speak on "Herbivory of Citrus Fruit by European Earwigs in California" at 4 p.m., Wednesday, Sept. 29. This will be an in-person seminar.
No seminar will be held Nov. 3, which conflicts with the annual meeting of the Entomological Society of America (ESA), set Oct. 31-Nov. 3 in Denver, Colo. Many faculty attend the annual meeting.
The seminars are open to all interested persons.
Siddique joined the UC Davis Department of Entomology and Nematology in July 2019 after serving as a research group leader for several years at the University of Bonn, Germany. Research in the Siddique lab focuses on basic as well as applied aspects of interaction between parasitic nematodes and their host plants. "The long-term object of our research is not only to enhance our understanding of molecular aspects of plant–nematode interaction but also to use this knowledge to provide new resources for reducing the impact of nematodes on crop plants in California."
For further information on the seminars, contact Siddique at ssiddique@ucdavis.edu.


- Author: Kathy Keatley Garvey
Take the case of a male monarch reared, released and tagged by Steven Johnson in a Washington State University citizen-science project operated by WSU entomologist David James. Johnson tagged and released the monarch on Sunday, Aug. 28, 2016 in Ashland, Ore. Seven days later, on Sept. 5, it fluttered into our family's backyard pollinator garden in Vacaville, Calif., where we photographed it.
"So, assuming it didn't travel much on the day you saw it, it flew 285 miles in 7 days or about 40.7 miles per day," James said. "Pretty amazing." (See Bug Squad blog)
But how do monarchs know when to migrate? You can find out when you attend the UC Davis Bohart Museum of Entomology open house on Saturday, Jan. 18 from 1 to 4 p.m. in Room 1124 of the Academic Surge Building, Crocker Lane.
Doctoral student Yao Cai, a fourth-year doctoral student in the Joanna Chiu lab who studies circadian clocks in insects, will relate how monarchs know when to migrate. “Using Drosophila melanogaster (fruit fly) and Danaus plexippus (monarch butterfly), as models, we seek to understand how these insects receive environmental time cues and tell time, how they organize their daily rhythms in physiology and behavior, such as feeding, sleep and migration (in monarch butterfly)," he says.
Cai is one of six doctoral students who will be showcasing their research. The event is free and family friendly.
Visitors not only will have the opportunity to talk to graduate students about their research and glean information about insects, but will be able see their work through a microscope. In fact, eight microscopes will be set up, Yang said.
In addition to Cai, doctoral students participating and their topics:
Ants: Zachary Griebenow of the Phil Ward lab, UC Davis Department of Entomology and Nematology
Assassin flies: Charlotte Herbert Alberts, who studies with major professor Lynn Kimsey, director of the Bohart Museum, UC Davis Department of Entomology and Nematology
Bats (what insects they eat): Ecologist Ann Holmes of the Graduate Group in Ecology, Department of Animal Science, and the Genomic Variation Laboratory, who studies with major professors Andrea Schreier and Mandi Finger.
Bark Beetles: Crystal Homicz. who studies with Joanna Chiu, UC Davis Department of Entomology and Nematology and research forest entomologist Chris Fettig, Pacific Southwest Research Station, USDA Forest Service, Davis.
Forensic entomology: Alexander Dedmon, who studies with Robert Kimsey, UC Davis Department of Entomology and Nematology
Some doctoral students also will deliver PowerPoint presentations or show slides. The projects:
Bark Beetles
“Did you know that between 1987 and 2017 bark beetles were responsible for more tree death than wildfire?” asks Crystal Homicz, a first-year doctoral student. “Bark beetles are an incredibly important feature of forests, especially as disturbance agents. My research focuses on how bark beetles and fire interact, given that these are the two most important disturbance agents of the Sierra Nevada. At my table, I will discuss how the interaction between bark beetles and fire, why bark beetles and fire are important feature of our forest ecosystem, and I will discuss more generally the importance of bark beetles in many forest systems throughout North America.
“I will have several wood samples, insect specimens and photographs to display what bark beetle damage looks like, and the landscape level effects bark beetles have. I will also have samples of wood damage caused by other wood boring beetles and insects. My table will focus widely on the subject of forest entomology and extend beyond beetle-fire interactions.”
Visitors, she said, can expect to leave with a clear understanding of what bark beetles are and what they do, as well as a deeper understanding of the importance of disturbance ecology in our temperate forests.
Assassin Flies
Charlotte Alberts, a fifth-year doctoral candidate, will display assassin flies and their relatives, as well as examples of prey they eat and/or mimic. Visitors can expect to learn about basic assassin fly ecology and evolution. Alberts studies the evolution of assassin flies (Diptera: Asilidae) and their relatives.
“Assassin flies are voracious predators on other insects and are able to overcome prey much larger than themselves,” she said. “Both adult and larval assassin flies are venomous. Their venom consists of neurotoxins that paralyze their prey, and digestive enzymes that allow assassin flies to consume their prey in a liquid form. These flies are incredibly diverse, ranging in size from 5-60mm, and can be found all over the world! With over 7,500 species, Asilidae is the third most specious family of flies. Despite assassin flies being very common, most people do not even know of their existence. This may be due to their impressive ability to mimic other insects, mainly wasps, and bees.”
For her thesis, she is trying to resolve the phylogenetic relationships of Asiloidea (Asilidae and their relatives) using Ultra Conserved Elements (UCEs), and morphology. "I am also interested in evolutionary trends of prey specificity within Asilidae, which may be one of the major driving forces leading to this family's diversity."
Bats
Ecologist Ann Holmes, a fourth-year doctoral student, is studying what insects that bats eat. "I will be talking about my research project that looks at insects eaten by bats in the Yolo Bypass. The insects eat crops such as rice, so bats provide a valuable service to farmers. Hungry bats can eat as much as their own body weight in insects each night."
"Visitors can expect to learn how DNA is used to detect insects in bat guano (poop)." "Insects in bat poop are hard to identify because they have been digested, but I can use DNA to determine which insects are there," she said. "We care about which insects bats eat because bats are natural pest controllers. With plenty of bats we can use less pesticide on farms and less mosquito repellent on ourselves."
Ants
Zachary Griebenow, a third-year doctoral student, will be showcasing or discussing specimens of the ant subfamily Leptanillinae, most of them male. “I will be showing specimens of the Leptanillinae under the microscope, emphasizing the great morphological diversity observed in males and talking about my systematic revision of the subfamily," he said. "In particular, I want to explain how the study of an extremely obscure group of ants can help us understand the process of evolution that has given rise to all organisms."
Forensic Entomology
Forensic entomologist Alex Dedmon, a sixth-year doctoral student, will display tools and text and explain what forensic entomology is all about. "My research focuses on insect succession. In forensic entomology, succession uses the patterns of insects that come and go from a body. These patterns help us estimate how long a person has been dead. Visitors can expect to learn about the many different ways insects can be used as evidence, and what that evidence tells us."
Other Open House Activities
The family craft activity will be painting rocks, which can be taken home or hidden around campus. "Hopefully some kind words on rocks found by random strangers can also make for a kinder better future,” said Yang.
In addition to meeting and chatting with the researchers, visitors can see insect specimens (including butterflies and moths), meet the critters in the live “petting zoo” (including Madagascar hissing cockroaches, walking sticks and tarantulas) and browse the gift shop, containing books, insect-themed t-shirts and sweatshirts, jewelry, insect-collecting equipment and insect-themed candy.
The Bohart Museum, directed by Professor Lynn Kimsey and founded by noted entomologist Richard M. Bohart (1913-2007), houses a global collection of nearly eight million specimens. It is also the home of the seventh largest insect collection in North America, and the California Insect Survey, a storehouse of insect biodiversity.
The insect museum is open to the public Mondays through Thursdays from 9 a.m. to noon and 1 to 5 p.m., except on holidays. More information on the Bohart Museum is available on the website at http://bohart.ucdavis.edu or by contacting (530) 752-0493 or bmuseum@ucdavis.edu.

