Professor and Department Chair Joanna Chiu Elected Fellow of the AAAS

Molecular geneticist and physiologist Joanna Chiu, professor and chair of the UC Davis Department of Entomology and Nematology and a professor in the Department of Neurobiology, Physiology, and Behavior, is a newly elected Fellow of the American Association for the Advancement of Science (AAAS) for her extraordinary achievements involving circadian clock research.

AAAS officials announced today (March 26) that Professor Chiu was singled out “for contributions to the understanding of the molecular mechanisms by which endogenous circadian clocks interact with environmental and metabolic signals to regulate animal biological rhythms.”

A member of the Department of Entomology and Nematology since 2010, Chiu is internationally recognized for her research on the molecular and cellular mechanisms that regulate circadian and seasonal biology, and for her work on invasive species genomics. Her peers also praise her teaching, mentoring, and leadership. 

AAAS Fellows are “a distinguished cadre of scientists, engineers and innovators recognized for their achievements across disciplines, from research, teaching, and technology to administration in academia, industry and government, to excellence in communicating and interpreting science to the public.” Other UC Davis faculty in the AAAS Fellow Class of 2025 are Gitta Coaker, Plant Pathology; David Segal, Biochemistry and Molecular Medicine; and Janine LaSalle, Medical Microbiology and Immunology.

“I investigate the regulation of animal circadian rhythms by using a combination of molecular genetics, biochemical, genomic, and proteomic approaches,” Chiu said. “The overall goal of my laboratory research is to dissect the molecular and cellular mechanisms that control the circadian clock in animals, and to investigate how this endogenous timer interacts with the environment and cellular metabolism to drive rhythms of physiology and behavior. Since circadian disruption has been identified as a risk factor for a wide range of human diseases, our research will provide insights into the health consequences when human lifestyles are in conflict with natural day-night cycles. More importantly, our research may pave the way to new therapeutic strategies to correct human disorders and pathologies associated with clock disruption.” 

Vinegar Fly as a Model

Chiu uses the vinegar fly, Drosophila melanogaster, as a model to understand the molecular makeup of the animal circadian clock. Through genomic approaches, her laboratory studies insect invasion biology and insecticide resistance development to glean new strategies for controlling agricultural pests.

In her letter of nomination, Professor Stacy Harmer of the UC Davis Department of Plant Biology, a fellow chronobiologist, wrote “Dr. Chiu’s research quality and output, her teaching and mentoring, and her service on campus and to the greater scientific community are all remarkable.”

“Joanna’s research is centered on three major topics,” Harmer noted. “First, her longest-term work is focused on the molecular and cellular mechanisms that regulate the animal circadian clock and how the clock influences organismal physiology. More recently, she has extended these studies to investigate the molecular and neuronal mechanisms regulating seasonal biology. Finally, she is using genomic tools to study the physiology of insect pests that have significant impacts on agriculture. The first two areas have significant implications for our understanding of processes that impact human health while the third is relevant to the development of new strategies for controlling agricultural pests and thus contributing to long-term global food security.”

ESA Honors

 Chiu was recently honored as a 2025 Fellow of the Entomological Society of America (ESA). She is a member and co-leader of the Spotted-Wing Drosophila Resistance Team, led by UC Davis Distinguished Professor Emeritus Frank Zalom, that won the 2026 Entomology Team Award from the ESA’s Pacific Branch (PBESA). 

In an earlier interview, Zalom praised Chiu’s outstanding research and academic achievements, her publication record, her major grants, and “her notable impact on students and stakeholders.”

Dedicated to teaching and mentoring, Chiu received the 2024 PBESA Distinction in Student Mentoring Award; the 2023 UC Davis Chancellor's Award for Excellence in Mentoring Undergraduate Research; and the 2022 UC Davis Academic Senate Distinguished Teaching and Mentoring Award for her contributions to graduate and professional mentoring. Chiu co-founded and co-directs the campuswide Research Scholars Program in Insect Biology (RSPIB), a mentoring research program for undergraduates. RSPIB has trained more than 140 undergraduate researchers since its founding in 2011.

As the director of the National Institutes of Health-funded Postbaccalaureate Research Education Program at UC Davis since 2022, Chiu facilitates the successful transition of trainees from undergraduate to graduate education. 

President-Elect of SRBR

Chiu currently is president-elect of the Society for Research on Biological Rhythms (SRBR) for 2024-2026 and will serve as SRBR president in 2026-2028. Her many other honors include the 2008 U.S. National Institutes of Health Pathway to Independence Award, the 2005 U.S. National Institutes of Health Postdoctoral Individual National Research Award, the UC Davis Chancellor's Fellowship in 2018, and the ESA Plant Insect Ecosystems Section Integrated Pest Management Team Award in 2019.

A native of Hong Kong, Joanna obtained her bachelor’s degree in biology and music, magna cum laude, at Mount Holyoke College, South Hadley, Mass., and her doctorate in biology, with a focus on molecular genetics, at New York University. She completed her postdoctoral research in molecular chronobiology at the Center for Advanced Biotechnology and Medicine at Rutgers, the State University of New Jersey.

A longtime administrator, Chiu served as vice chair of the UC Davis Department of Entomology and Nematology from 2016 to 2023 and became chair in 2023.

AAAS launched the Fellows program in 1874. The AAAS Council elects Fellows annually from a list of approved nominations from the Section Steering Committees.