Like humans, fruit flies eat more and sleep less when they're isolated and lonely.

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:

1. 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 .
2. 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.
3. 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.
4. 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.
5. 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. 

Yao Cai, who received his doctorate in entomology in September from UC Davis, will present his exit seminar, "How Do Flies Tell the Time of Day?" at the next UC Davis Department of Entomology and Nematology seminar, set Wednesday, Oct. 26.

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.
  
  
• 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.
  
  
• 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. 

Sergio Hidalgo Sotelo, a postdoctoral fellow in the laboratory of molecular geneticist and physiologist Joanna Chiu, UC Davis Department of Entomology and Nematology, has been named a 2021 Pew Latin American Fellow in the Biomedical Sciences. 

A native of Puente Alto, Santiago, Chile, he joined the Chiu lab in 2020 and is exploring the molecular and neural circuits that regulate seasonal biology in animals. 

Under this Pew program, young scientists from Latin America receive postdoctoral training in the United States, “giving them an opportunity to further their scientific knowledge by promoting exchange and collaboration between investigators in the United States and Latin America—ultimately resulting in advances in research in Latin America,” Pew spokesperson Abigail Major said. 

Sergio is one of 10 post-docs from across Latin America—including Argentina, Brazil, Chile, Mexico, Peru, and Uruguay—to receive two years of funding to conduct research. The fellows will work under the mentorship of prominent biomedical scientists, including alumni of the Pew Scholars Program in the Biomedical Sciences. 

“Sergio's academic and research track record is outstanding,” said Chiu, associate professor and vice chair of the Department of Entomology and Nematology. “Although he has only worked in my laboratory for less than a year, I have been very impressed by his drive, independence, ingenuity, and intellect. Given his long-standing interest in understanding how neuronal mechanisms regulate behavior and physiology, his research goals align very well with my laboratory. I am excited he has been named a Pew Latin American Fellow; it is very well deserved. I look forward to partnering with him to study regulation of seasonal biology."

Chiu is a Chancellor's Fellow whose research expertise includes molecular genetics of biological timing and posttranslational regulation of proteins. She uses animal models including Drosophila melanogaster and mice to study the mechanisms that regulate circadian and seasonal physiology and behavior. 

Hidalgo Sotelo wrote his dissertation on “Using Drosophila to Model Schizophrenia Symptoms.” He was awarded a dual doctorate in physiology and pharmacology in 2020 from the University of Bristol, and Pontificia Universidad Católica de Chile. He also holds a master's degree in biological science from Pontificia Universidad Católica de Chile and a bachelor's degree in biochemistry there. 

Of his research in the Chiu lab, he explained: “Animals use environmental cues to match their behaviors with the season: as temperatures fall and days grow shorter, birds fly south, and fruit flies curtail their reproduction, Hidalgo Sotelo said. “But little is known about the mechanisms that allow animals to synchronize with the calendar. I will work on elucidating this machinery, using an array of cutting-edge techniques in cell and molecular biology, neurogenetics, and genomics, aiming to identify the molecules that contribute to the seasonal oscillations of EYA, a key component of the seasonal timer previously described by a number of groups, including Dr. Chiu's lab. These findings will broaden our understanding of seasonal biology and could lead to new approaches for treating disorders that display seasonality, including infectious diseases and seasonal affective disorder.”  

Another Pew postdoctoral fellow is Mariana Duhne Aguayo of the UC San Francisco lab of Joseph Berke where she is mapping the neural circuits that calibrate how swiftly animals move. 

Other postdocs are training in labs at Harvard University, New York University Grossman School of Medicine, Texas Tech University Health Sciences Center, University of Virginia, Washington University School of Medicine, Massachusetts General Hospital, and New York University Langone Health. 

Pew Trust officials also announced the recipients of the Pew Scholars in Biomedical Sciences, who include Bennett Penn, assistant professor in the UC Davis Department of Medicine's Division of Infectious Diseases. The Pew Scholars Program in the Biomedical Sciences provides funding to young investigators of outstanding promise in science relevant to the advancement of human health. 

DAVIS--Daniel Matute, assistant professor, Department of Biology, University of North Carolina at Chapel Hill, will speak on "Hybrid Speciation in Drosophila" at a noon seminar hosted Wednesday, Jan. 14 by the UC Davis Department of Entomology and Nematology.

The event takes place from 12:10 to 1 p.m. in 122 Briggs Hall.  Meredith Cezner, graduate student in the Louie Yang lab, is the host and will introduce him.  Matute researches the genetics, behavior, and ecological context of reproductive isolation in the genus Drosophila. 

His abstract: "Gene flow between species has been thought to oppose the divergence process, but there has been no systematic treatment of how species persist in the face of gene flow in secondary contact. Furthermore, while hybridization is known to generate new species in plants and fungi, it is not known how prevalent is the creative role of hybridization is in animal speciation. An approach to address the relative importance of hybrid speciation is experimental evolution. Our results test the possibility of hybrid speciation at different phylogenetic scales as a formal test of the likelihood of hybrid speciation. This project constitutes the first experimental approach to test the possible role of hybridization in generating new animal species."

Much of Matute's work examines the interactions between island endemics and cosmopolitan species in the Seychelles archipelago, where natural zones of secondary contact allow for the study of hybridization and reproductive isolation in the field.  He received this year's Theodosius Dobzhansky Prize from the Society for the Study of Evolution, an award recognizing “the accomplishments and future promise of an outstanding young evolutionary biologist."

Matute obtained a dual degree in biology and microbiology at Universidad de Los Andes in Columbia in 2005. He completed his doctorate in ecology and evolution with Jerry Coyne at the University of Chicago in the spring of 2010. 

One of his research papers, "Macroevolutionary Speciation Rates are Decoupled from the Evolution of Intrinsic Reproductive Isolation in Drosophila and Birds," was published in the Proceedings of the National Academy of Sciences. 

The abstract: 

"The rate at which speciation occurs varies greatly among different kinds of organisms and is frequently assumed to result from species- or clade-specific factors that influence the rate at which populations acquire reproductive isolation. This premise leads to a fundamental prediction that has never been tested: Organisms that quickly evolve prezygotic or postzygotic reproductive isolation should have faster rates of speciation than organisms that slowly acquire reproductive isolation. We combined phylogenetic estimates of speciation rates from Drosophila and birds with a method for analyzing interspecific hybridization data to test whether the rate at which individual lineages evolve reproductive isolation predicts their macroevolutionary rate of species formation. We find that some lineages evolve reproductive isolation much more quickly than others, but this variation is decoupled from rates of speciation as measured on phylogenetic trees. For the clades examined here, reproductive isolation—especially intrinsic, postzygotic isolation—does not seem to be the rate-limiting control on macroevolutionary diversification dynamics. These results suggest that factors associated with intrinsic reproductive isolation may have less to do with the tremendous variation in species diversity across the evolutionary tree of life than is generally assumed."

See more of his research publications.

The remainder of noon-hour seminars for the winter quarter:

Jan. 21
George Dimopoulous
Title of Seminar: "Exploiting Infection Bottlenecks in the Mosquito to Control  Human Disease"
Director of the Parasitology Core Facility
John Hopkins Bloomberg School of Public Health
Professor, Molecular Microbiology and Immunology
Baltimore, Md.
Nominator/host: Jiawen Xu, graduate student, Bruce Hammock lab, UC Davis Department of Entomology and Nematology

Jan. 28
Michael Parrella
Title of Seminar: "To Antarctica and Back:  The Search for Beligica antarctica (Diptera;  Chironomidae)”
Professor and chair of the UC Davis Department of Entomology and Nematology

Feb. 4
Jay Evans
Title of Seminar: "What's It Like  Inside a Bee? Genetic Approaches to Honey Bee hHealth"
Research entomologist
USDA Agricultural Research Service (USDA/ARS)
Beltsville, MD.
Nominator/host: Marin County Beekeepers

Feb. 11
Amro Zayed
Title of Seminar: "Bee Genes, Behavior and Adaptation"
Professor, Department of Biology
York University
Toronto, Canada
Nominator/host: Brian Johnson, assistant professor, UC Davis Department of Entomology and Nematology

Feb. 18 
Steven Frank
Title of Seminar: "Can Forests Take the Heat? Managing Pests and Ecosystem Services in a Warming Climate"
Assistant Professor, Department of Biology
North Carolina State University
Raleigh, N.C.
Nominator/host: Michael Parrella, professor and chair, UC Davis Department of Entomology and Nematology

March 4
Brian Wiegmann
Executive Director of Genome Research Laboratory
North Carolina State University
Raleigh, N.C.
Nominator/host:Steve Nadler, professor, UC Davis Department of Entomology and Nematology

March 11
Thomas Eltz
Title of Seminar: "Perfume Making and Signalling in Orchid bees: New Light on an Old Enigma"
Chemical Ecologist
University of Bochum
Bochum, Germany
Nominator/host: Santiago Ramirez, faculty member,  UC Davis Department of Evolution and Ecology

Coodinating the seminars is Professor Steve Nadler at sanadler@ucdavis.edu.