- Author: Kathy Keatley Garvey
And how do animals use changes in day length and temperature to adapt their physiology and behavior to seasonal environmental changes?
Those are the questions that UC Davis postdoctoral researcher Sergio Hidalgo Sotelo asked himself, and now newly published research that he spearheaded in the laboratory of molecular geneticist-physiologist Joanna Chiu—building on previous Chiu lab research--sheds more light on the topic.
The research article, “Seasonal Cues Act Through the Circadian Clock and Pigment Dispersing Factor to Control EYES ABSENT and Downstream Physiological Changes,” appears in the current edition of the journal Current Biology.
Sotelo, a Pew Latin American Fellow in the Biomedical Sciences fellow in the lab of Professor Chiu, vice chair of the UC Davis Department of Entomology and Nematology, collaborated with Chiu and two lab members: Christine Tabuloc, a doctoral candidate, and Maribel Anguiano, now a doctoral student in the UC Davis Neuroscience graduate program and a former member of National Institutes of Health Postbaccalaureate Research Education Program (PREP).
“This work,” Chiu said, “certainly helps us progress towards a more complete picture of how animal seasonality is regulated at the molecular and cellular level. Excitingly, it also raises many more interesting questions, which Sergio and our team cannot wait to answer.”
Their summary:
Organisms adapt to seasonal changes in photoperiod and temperature to survive; however, the mechanisms by which these signals are integrated in the brain to alter seasonal biology are poorly understood. We previously reported that EYES ABSENT (EYA) shows higher levels in cold temperature or short photoperiod and promotes winter physiology in Drosophila. Nevertheless, how EYA senses seasonal cues is unclear. Pigment-dispersing factor (PDF) is a neuropeptide important for regulating circadian output rhythms. Interestingly, PDF has also been shown to regulate seasonality, suggesting that it may mediate the function of the circadian clock in modulating seasonal physiology. In this study, we investigated the role of EYA in mediating the function of PDF on seasonal biology. We observed that PDF abundance is lower on cold and short days as compared with warm and long days, contrary to what was previously observed for EYA. We observed that manipulating PDF signaling in eya+ fly brain neurons, where EYA and PDF receptor are co-expressed, modulates seasonal adaptations in daily activity rhythm and ovary development via EYA-dependent and EYA-independent mechanisms. At the molecular level, altering PDF signaling impacted EYA protein abundance. Specifically, we showed that protein kinase A (PKA), an effector of PDF signaling, phosphorylates EYA promoting its degradation, thus explaining the opposite responses of PDF and EYA abundance to changes in seasonal cues. In summary, our results support a model in which PDF signaling negatively modulates EYA levels to regulate seasonal physiology, linking the circadian clock to the modulation of seasonal adaptations.”
Sotelo, who specializes in chronobiology (the study of biological rhythms), molecular genetics and biochemistry, won the 2021 Young Neuroscientist Symposium Award at the meeting of the Chilean Society for Neuroscience, Chile, and received a merit award for his presentation at the 2022 Society for Research on Biological Rhythms (SRBR) Biennial Conference in Amelia Island, Florida.
A native of Puente Alto, Santiago, Chile, Sotelo joined the Chiu lab as a postdoctoral fellow in the summer of 2020. He 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 work under the mentorship of prominent biomedical scientists, including alumni of the Pew Scholars Program in the Biomedical Sciences.
Sotelo holds three degrees from Pontificia Universidad Católica de Chile: a bachelor's degree in biochemistry, with distinction (2015), a master's degree in neurochemistry (2017) and a doctorate in cellular and molecular biology, with distinction (2020). Also in 2020, he received a doctorate in sensory physiology and animal. Behavior from the University of Bristol, Bristol, UK.
Resource:
EYES ABSENT and TIMELESS Integrate Photoperiodic and Temperature Cues to Regulate Seasonal Physiology in Drosophila, published June 15, 2020, Proceedings of the National Academy of Sciences (PNAS), lead author Antoine Abrieux and co-authors Joanna Chiu, Yao Cai, and Yongbo Xue.
- Author: Kathy Keatley Garvey
Fettig's seminar also will be virtual. The Zoom link:
https://ucdavis.zoom.us/j/95882849672
UC Davis doctoral student Crystal Homicz will host him.
"Bark beetles are a major disturbance in western forests," Fettig says in his abstract. "Several recent outbreaks of species such as mountain pine beetle, spruce beetle, and western pine beetle are among the most severe in recorded history. There is strong evidence that climate change has increased the impacts of bark beetles. For example, in California warming and exceptional drought resulted in mortality of more than a 100 million trees from 2014-2017. Much of this mortality was attributed to western pine beetle colonizing drought-stressed hosts. I will discuss observed and projected changes in climate, the direct and indirect effects of climate change on bark beetles and forests, and management actions that increase the resilience of forests to bark beetles and climate change."
Fettig advises Homicz, who began her studies with forest entomologist and chemical ecologist Steve Seybold (1959-2019). Her dissertation research focuses on western pine beetle and red turpentine beetle interactions with forest disturbances, such as drought, wildfire and prescribed fire.
Fettig received his bachelor's degree (1993) and a master's degree (1996) from Virginia Tech University, and his doctorate in forest entomology in 1999 from the University of Georgia.
Of his current research, he writes on the USDA website: "My personal research program has three major emphases: (1) determination of short and long-term implications to forest health of prescribed fire and/or mechanical fuel treatments (silvicultural thinning) used in the large-scale restoration of fire-adapted forest ecosystems, (2) development of chemical, silvicultural and semiochemical-based monitoring and management tactics for Dendroctonus and Ips bark beetles, and (3) determination of the role of semiochemicals in the behavior of bark beetle species of economic importance."
Fettig's most recent publication, "Fire and Insect Interactions in North American Forests," co-authored by Homicz and several other colleagues, appears in a 2022 edition of Current Forestry Reports. Abstract: "Fire has both positive and negative effects on insects. Bark beetle and defoliator epidemics have positive and negative effects on wildfires. Additional study of these relationships is warranted given the effects of climate change on forests and forest disturbances, recent declines in some pollinator species in North America, and interests in restoring fire-adapted forest ecosystems."
The UC Davis Department of Entomology and Nematology's winter seminars are held on Wednesdays at 4:10 p.m. in 122 Briggs Hall. All are virtual. They are coordinated by urban landscape entomologist Emily Meineke, assistant professor. (See schedule.) She may be reached at ekmeineke@ucdavis.edu for technical issues.
- Author: Kathy Keatley Garvey
The seminar, hosted by UC Davis doctoral student Crystal Homicz, begins at 4:10 p.m. in 122 Briggs Hall. The Zoom link: https://ucdavis.zoom.us/j/
"Only in the last few years have we begun to uncover how bristlecone pines do this," he related. "We use field work, chemical ecology and laboratory assays to understand interactions between long-lived bristlecone pine species (Great Basic Bristlecone pine and foxtail pine), co-occurring limber pine, and the mountain pine beetle (MPB). I will talk about recent and going research examining (1) the plant volatile cues used by host-searching MPBs, (2) the terpene-based phloem defenses used against MPB larvae, and (3) tradeoffs between constitutive and induced defenses across these pine species. Understanding these interactions provides insight into the longevity of bristlecone pines, the implications for these species under climate change, and development of management tool to protect trees from bark beetles."
Runyon, based on the Montana State University (MSU) campus in Bozeman, received his bachelor's degree in biology and mathematics in 1998 from the University of Virginia's College at Wise, Va.; his master's degree in entomology from MSU in 2001; and his doctorate in entomology in 2008 from Pennsylvania State University Park, Pa.
In 2014, at a ceremony in Washington, D.C., he received the Presidential Early Career Award for Science and Engineering (PECASE), the highest honor bestowed by the U.S. government on science and engineering professionals in the early stages of their independent research careers.
Runyon is also involved in assessing native plants desired by native bees. (See research and news story)
Homicz, advised by research entomologist Chris Fettig of the USDA's Pacific Southwest Research Station, Davis, began her studies with forest entomologist and chemical ecologist Steve Seybold (1959-2019). Her dissertation research focuses on western pine beetle and red turpentine beetle interactions with forest disturbances, such as drought, wildfire and prescribed fire.
The UC Davis Department of Entomology and Nematology's regularly scheduled Wednesday seminars are at 4:10 p.m. on every Wednesday through March 15. They are coordinated by urban landscape entomologist Emily Meineke, assistant professor. (See schedule.) She may be reached at ekmeineke@ucdavis.edu.
- Author: Kathy Keatley Garvey
And it was all about the beetles: "Beetlemania."
Some 500 visitors browsed the displays at the Bohart Museum of Entomology open house, chatted with scientists, photographed the specimens, engaged in arts and crafts, and then headed over to the petting zoo to introduce themselves to the Madagascar hissing cockroaches and stick insects.
The event took place from 1 to 4 p.m. in the Bohart Museum's headquarters in Room 1124 of the Academic Surge Building, 455 Crocker Lane. Bohart personnel greeted the guests: Lynn Kimsey, director of the Bohart Museum; Tabatha Yang, education and outreach coordinator; Brennen Dyer, collections manager; Brittany Kohler, research associate; Jeff Smith, curator of the Lepidoptera collection; and Greg Kareofelas, Lepidoptera host assistant.
- Beetles from Belize: Professor Fran Keller of Folsom Lake College, a Bohart Museum scientist, and her assistant, Iris Bright, a graduate student in the Jason Bond lab.
- Carabid beetles: Kipling "Kip" Will, associate professor with the UC Berkeley Department of Environmental Science, Policy and Management
- Burying beetles: Tracie Hayes, a doctoral candidate and burying beetle researcher in the laboratory of Professor Louie Yang, UC Davis Department of Entomology and Nematology. (She presented a video she created, "A Clearance of Death on Behalf of Life" at https://youtu.be/cGLOE7SrbiU.)
- Bark beetles: Curtis Ewing, a senior environmental scientist with Cal Fire's Forest Entomology and Pathology
- Children's tree-related activities: Jonelle Mason, a UC Agriculture and Natural Resources (UC ANR) employee and coordinator of Project Learning Tree (PLT) California, an initiative of the Sustainable Forestry Initiative,
- Tree cores and boring tools: UC Davis graduate student Jennifer Cribbs of the Graduate Program of Environmental Policy and Management
- Diabolical ironclad beetles: Brittany Kohler, Bohart research associate
- Family arts and crafts: Allen Chew, Sol Wantz and Kat Taylor, all UC Davis undergraduate students
- Petting zoo: Kaitai Liu, undergraduate student in the Jason Bond lab; Veronica Casey, graduate student in Shahid Siddique lab; and Grace Horne, graduate student in Emily Meineke lab
The Bohart Museum, dedicated to "understanding, documenting and communicating terrestrial arthropod diversity," was founded in 1946 and named for UC Davis professor and noted entomologist Richard Bohart. It houses a global collection of eight million insect specimens, plus a live "petting zoo," featuring Madagascar hissing cockroaches, walking sticks and tarantulas; and a year-around gift shop, stocked with insect-themed books, posters, jewelry, t-shirts, hoodies and more. The museum is open to the public from 8 a.m. to noon and from 1 to 5 p.m., Mondays through Fridays.
- Author: Kathy Keatley Garvey
Plans are being finalized for the popular "Day of Science."
Scheduled Saturday, Feb. 18, it is billed as a “free, family friendly educational event for the community where visitors get to meet and talk with UC Davis scientists and see amazing objects and organisms from the world around us,” according to Biodiversity Museum Day chair Tabatha Yang, education and outreach coordinator for the Bohart Museum of Entomology.
Eleven museums or collections on campus will showcase their work:
- Anthropology Museum, 328 Young Hall and grounds, noon to 4 p.m.
- Arboretum and Public Garden, Habitat Gardens in the Environmental GATEway, adjacent to the Arboretum Teaching Nursery on Garrod Drive, 9 a.m. to 1 p.m.
- Bohart Museum of Entomology, Room 1124 and main hall of the Academic Surge Building, Crocker Lane, 9 a.m. to noon and 1 to 4 p.m.
- Botanical Conservatory, the greenhouses along Kleiber Hall Drive, 11 a.m. to 3 p.m.
- California Raptor Center, 1340 Equine Lane, off Old Davis Road, 9 a.m. to 3 p.m.
- Center for Plant Diversity, Sciences Laboratory Building/Esau Science Hall, off Kleiber Hall Drive, 11 a.m. to 3 p.m.
- Nematode Collection, Sciences Laboratory Building/Esau Science Hall, off Kleiber Hall Drive, 9 am. to 3 p.m.
- Marine Invertebrate Collection, Sciences Laboratory Building/Esau Science Hall, off Kleiber Hall Drive, 9 am. to 3 p.m.
- Museum of Wildlife and Fish Biology, Room 1394, Academic Surge Building, 455 Crocker Lane, 10 a.m. to 2 p.m.
- Paleontology Collection, (Department of Earth and Planetary Sciences) 434 LaRue Road, 12 noon to 4 p.m.
- Phaff Yeast Culture Collection, Robert Mondavi Institute Brewery and Food Processing facility, Old Davis Road, 10 a.m. to 2 p.m. (See news story)
The UC Davis Biodiversity Museum Day is traditionally held on Presidents' Day Weekend at various venues on campus. The 2022 event, however, took place March 6 in the UC Davis Conference Center and drew some 1000 visitors. This year, it's back home to the individual departments where scientists will be on hand to greet visitors and answer questions.
Many middle school and high school students attend the event to take the opportunity to consider careers in science.
All participating museums and collections have active education and outreach programs, Yang said, but the collections are not always accessible to the public.