- Author: Kathy Keatley Garvey
It's 3:47 p.m., on Sunday, June 4. I am watching a honey bee nectaring on a zinnia in our pollinator garden. She collects, lingers and then leaves.
It was like (A) Apis mellifera to (Z) zinnia. I thought: "A honey bee, Apis mellifera, is leaving a pink zinnia after gathering nectar and pollen for her colony. Everyone must leave what they love to become who they want to be or what they want to become."
So it is with commencements. Molecular geneticist-physiologist Joanna Chiu, professor and vice chair of the UC Davis Department of Entomology and Nematology, captured this image at a PhD commencement today and posted it on Twitter: "What do we have here? Congratulations Dr. Cai, Dr. Griebenow, Dr. Lewald and Dr. Tabuloc!"
That would be Yao Cai, Christine Tabuloc and Kyle Lewald of the Chiu lab and Zachary Griebenow of the Phil Ward lab. Former doctoral students, then doctoral candidates...and now PhDs...
Kyle? Member of the Integrative Genetics and Genomics Graduate Group. Others? Entomology Graduate Group.
Professor Chiu captured it perfectly! What a proud and glorious moment!
- Author: Kathy Keatley Garvey
Professor Chiu is the newly announced faculty recipient of the 2023 Chancellor's Award for Excellence in Mentoring Undergraduate Research.
The three-pronged Chancellor's Award, launched in 1994, annually honors three outstanding mentors: a graduate student; a postdoctoral fellow or project scientist; and a faculty member.
Chiu, who joined the faculty in 2010, focuses her research on the molecular and cellular biology of circadian rhythms and seasonal rhythms.
Doctoral candidate Christine Tabuloc of the Chiu lab--she'll be receiving her PhD this month--nominated her for the award. Five Chiu lab alumni submitted a group letter of recommendation. (See more on Department of Entomology and Nematology website.)
A native of Hong Kong and a first-generation college student, Joanna received her bachelor's degree in biology and music from Mount Holyoke College, Mass., and her doctorate in molecular genetics in 2004 from New York University, New York. She trained as a postdoctoral fellow from 2004 to 2010 in molecular chronobiology at the Center for Advanced Biotechnology and Medicine, at Rutgers, the State University of New Jersey.
Chiu joined the Department of Entomology and Nematology in 2010 as an assistant professor, and advanced to associate professor and vice Chair in 2016, and to professor and vice chair in 2021. She was named one of 10 UC Davis Chancellor's Fellows in 2019, a five-year honor awarded to associate professors who excel in research and teaching. The UC Davis Academic Senate honored her with a Distinguished Teaching Award, Graduate/Professional category, in 2022.
Chiu co-founded and co-directs (with Professors Jay Rosenheim and Louie Yang) the campuswide Research Scholars Program in Insect Biology, launched in 2011 to provide undergraduates with a closely mentored research experience in biology. The program's goal is to provide academically strong and highly motivated undergraduates with a multi-year research experience that cultivates skills that will prepare them for a career in biological research.
What sparked your interest in science and in your field?
"In a way, maybe to try to escape from their expectations to be a doctor, I applied to attend college in the U.S.. far away from home so I can choose to study what I want. I did not know that research can be a career and I certainly have never ever dreamed of being a professor when I was a college student. I just know I love biological research so I can learn more about the natural world, I love asking questions, and I love the joy of discovery."
"In terms of my lab research focus in animal circadian rhythms, I first learned about this field of research in graduate school from my professors Justin Blau and Todd Holmes at New York University. I learned from them the extensive influence of internal biological clocks on animal physiology and behavior, and I have been hooked since."
What is your teaching/mentoring philosophy?
"As a first-generation college student and U.S. immigrant, I am familiar with the challenges faced by those who pursue a STEM career without a robust support system. This is why I value every opportunity to contribute to teaching and mentoring of diverse scientists and to create a safe space for them to learn and grow. Every student is different so I strive to provide tailored mentoring based on a trainee's learning style and career goals. It is obviously important for my trainees to learn about the scientific process, technical skills necessary for them to complete their research, and the subject matter relevant to their research project. But I feel that it is just as important or perhaps even more important for me to mentor them during their time in my lab so that they can learn about themselves and their career/life goals. I don't mentor my students so that they can all be like me; I guide them so that they can find their own paths."
She admires many teachers/mentors. "One of them is certainly my graduate advisor Professor Gloria Coruzzi. She is not only a very successful scientist, she is also one of the most determined and resilient person I have ever met. To be honest, I don't think I fully appreciated many of the lessons I learned from her until I started my own research program."
"My postdoctoral advisor Isaac Edery is another mentor I admire; he has incredible patience as a mentor and he was the person who made me understand teaching/mentoring is definitely not one size fits all. He is certainly one of the kindest persons I have met."
What are some of your outside interests?
"Outside of my research and my job, I really enjoy spending time with my dogs (Oliver and Kaia are Golden Retrievers and Phoebe is a Nova Scotia Duck Tolling Retriever). We do conformation, scentwork, obedience, dock diving, retriever training, and are starting to train in agility. I love to learn how to communicate with my dogs through all these activities. They all have different personalities. I also love going to competition and trials with them, meeting other dogs and owners; I really enjoy the camaraderie and we cheer each other on."
- Author: Kathy Keatley Garvey
A warm welcome!
"UC Davis is a big university, with a strong focus on research," the text begins. "Undergraduates can easily feel like they are lost in the crowd, and rarely get close mentorship from faculty or other research staff (how can you, when your classes have hundreds of students present?). And yet, some of the most important skills for research biologists cannot be taught in big lecture halls or even in lab courses; these skills, especially those linked to conducting cutting-edge research are best learned through close mentoring relationships with faculty, and through an opportunity to do research (try it, make mistakes, learn from those mistakes, and get it right the next time)."
The program, co-founded and co-directed by three faculty members of the UC Davis Department of Entomology and Nematology--distinguished professor Jay Rosenheim and professors Joanna Chiu and Louie Yang--"aims to provide undergraduates with a closely-mentored research experience in biology. Because insects can be used as model systems to explore virtually any area of biology (population biology; behavior and ecology; biodiversity and evolutionary ecology; agroecology; genetics and molecular biology; biochemistry and physiology; cell biology), faculty in the program can provide research opportunities across the full sweep of biology. The program's goal is to provide academically strong and highly motivated undergraduates with a multi-year research experience that cultivates skills that will prepare them for a career in biological research."
From the depths of this innovative and excellent program, launched in 2011, come outstanding scholars--scholars like Gwen Erdosh and Gary Ge, the first two recipients of the Dr. Stephen Garczynski Undergraduate Research Scholarship. This award, sponsored by the Pacific Branch, Entomological Society of America, memorializes Stephen Garczynski (1960-2019), a research geneticist at the USDA Agricultural Research Service in Wapato, Wash.,"who had an unmatched passion for mentoring undergraduate students in their research," according to the PBESA website.
Erdosh, a research scholar in the Yang lab, won the inaugural scholarship, presented in 2022. She's continuing her research, and as @gwentomologist, is sharing her knowledge of entomology with her 77,000 followers on Instagram.
This year Ge won the undergraduate scholarship. He studies with Yang and UC Davis Distinguished Professor Art Shapiro of the Department of Evolution and Ecology, and researches the American Apollo butterfly (Parnassius clodius) as a model to study how microclimatic conditions affect cold-adapted insects. Ge is a research assistant with Shapiro's Central California Butterfly Population and Diversity Trends Study, and works with Yang as a project manager and a research assistant on his Milkweed phenology study.
Ge will be honored at the annual PBESA meeting, April 2-5 in Seattle, which encompasses 11 Western states, plus Canada, Mexico and U.S. territories. He will receive a $1000 award for travel expenses and a waived registration fee.
Ge just finished writing a National Science Foundation's Graduate Research Fellowship Program (GRFP) grant proposal. The results are expected to be announced in April.
His hypothesis: "that mid-elevation populations of P. clodius have the best cold tolerance as overwintering eggs. The main factor behind this is snow cover. Snow cover is known to provide significant insulation to whatever is underneath, usually creating higher microclimatic temperatures under the snow than above. At mid-elevations, the winter temperatures are lower than at low elevations, and the snow cover is supposedly less and more unstable compared to higher elevations. This means the mid-elevation populations are likely exposed to the coldest winter temperature, and have locally adapted to it.”
Ge said he is testing his hypothesis “partly by looking at the supercooling points (SCPs) of diapausing eggs in different populations. The SCP indicates the freezing temperature of the egg, so it should be close to the lower lethal temperature. So, the population with the lowest average SCP would be the most cold-tolerant. I got some preliminary results recently indicating the SCP of the mid-elevation eggs is around -30 °C, which is pretty cold! On the side I am also testing the egg SCP of a Parnassius behrii population. This is a California endemic. It would be cool to see how their thermal tolerance differ from that of P. clodius as P. behrii is only found in high-elevation habitats (mostly around and above 9,000 feet).”
“The genus Parnassius is prone to global warming due to its affinity for alpine and arctic habitats, and several species are considered to be threatened," Ge said.
Shapiro, who has monitored butterfly populations across central California for the last 50 years, says that “Parnassians are a group of cold-adapted Northern Hemisphere butterflies that are becoming increasingly important as objects of physiological, ecological and evolutionary study. They are only likely to grow more important in the context of climate change. Thus, Gary's study is very timely and should attract plenty of attention! It is demanding given the rigorous conditions in which they breed and develop, and he is likely to learn a lot that will facilitate future lab and field studies.” On his research website, Art's Shapiro's Butterfly site, Shapiro describes P. clodius in detail.
Gary, born in Beijing, China, attended elementary school in New York City, middle school in Singapore, and high school in Hawaii, and now California for college. “This allowed me to have experience with a range of lepidopterans and ants and termites as well—social insects are my other favorite group.” He anticipates receiving his bachelor of science degree at UC Davis this year and hopes to enroll in graduate school at UC Davis.
Gary developed his passion for Parnassius during middle school. “When I was visiting my extended family in Tibet, I saw this small white butterfly flying through the seemingly lifeless alpine scree habitat at an elevation of around 1,5000 feet. I later found out that it was a Parnassius species and got immediately intrigued by the fact that they are mostly specialist of alpine and arctic habitats, living in some of the world's coldest and most hostile environments. Since many of the genus members have habitats restricted to mountain tops above the tree line, our P. behrii is an example, climate change--rising tree lines-would leave them nowhere to go. This makes better understanding the ecology of this genus utterly important.”
Congratulations to the scholars, their instructors, and to the UC Davis Research Scholars Program in Insect Biology. And kudos to PBESA for memorializing USDA research geneticist Stephen Garczynski and his "unmatched passion for mentoring undergraduate students in their research."
- Author: Kathy Keatley Garvey
That would include the larvae of Tuta absoluta, a South American tomato leafminer. In its adult stage, it's a moth in the family Gelechilidae. In its larval stage, it's a major agricultural pest.
Since 2008, it has invaded much of Europe, northern Africa, and the Middle East, according to a California Department of Food and Agriculture post.
It hasn't yet invaded the United States, but scientists say it has moved from South America as far north as Costa Rica.
The bug "is a serious and devastating pest of tomatoes, causing crop losses as high as 80 to 100% in areas where it is found," according to a Pest Alert article published by the UC Statewide Integrated Pest Management Program. "This insect bores into leaves, stems, flowers, and fruit, often leaving the fruit unmarketable and altering plant growth structure through destruction of stem apical buds or flower buds. To manage this insect, growers may be forced to greatly increase the number of insecticide applications to their tomato crops."
The article, by UC Davis scientists Kris Godfrey of the Contained Research Facility, and Frank Zalom and Joanna Chiu, both of the Department of Entomology and Nematology, points out that the "South American tomato leafminer spreads via commercial trade of plants and fruit infested with eggs, larvae, and pupae. The adult moths can fly, but it is not known if this movement contributes significantly to its spread. There are numerous regulations in place that should limit the spread of the South American tomato leafminer in imported commercial tomato plants and fruit. However, movement of fruit and plants by private individuals is not as strongly regulated."
Enter Kyle Lewald, a doctoral candidate in the laboratory of UC Davis molecular geneticist/physiologist Joanna Chiu. He will present his exit seminar on "Using Genomic Data to Understand and Prevent the Spread of Tuta absoluta" at 4:10 p.m., Wednesday, Feb. 22 in 122 Briggs and also on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/95882849672.
Chiu, professor and vice chair, UC Davis Department of Entomology and Nematology, will introduce him.
"Tuta absoluta is a serious agricultural pest of tomato plants," Lewald says in his abstract. "While initially discovered in Peru, it has rapidly invaded tomato fields around the world over the past century, causing widespread damage to the industry. The recent affordability of whole genome sequencing of insects opens the door to a wide number of applications to understand and control this pest."
"Using long read sequencing, we produced and annotated a highly contiguous T. absoluta genome assembly," Lewald noted. "Sequencing of individuals collected across many locations in Latin America allowed us to investigate population structure and diversity levels, as well as identify divergence times and possible migration events occurring between regions. Understanding these historical events can be key to predicting and preventing future invasion events. We also used comparative genomics between morphologically similar gelechiid species to develop efficient molecular diagnostics, allowing field researchers and stakeholders to identify Tuta absoluta rapidly to support quarantine and treatment efforts."
Lewald, who holds a bachelor's degree in molecular and cell biology (2016) from UC Berkeley joined the Chiu lab in 2018.
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. Urban landscape entomologist Emily Meineke, assistant professor, coordinates the seminars. (See schedule.) She may be reached at ekmeineke@ucdavis.edu for technical issues.
- Author: Kathy Keatley Garvey
Remember the spotted-wing drosophila, Drosophila suzukii?
Native to Southeast Asia, it infests soft-skinned fruits such as strawberries, raspberries, cherries, blueberries, blackberries, peaches and grapes. Scientists first detected it in the United States (central coastal region of California) in 2008.
If you attend UC Davis doctoral candidate Christine Tabuloc's exit seminar at 4:10 p.m., Wednesday, Feb. 15--in-person or virtually--you'll get a grasp of the work she's doing involving D. suzukii, a worldwide pest, and D. melanogaster, a common species used worldwide as a model organism in genetics.
Tabuloc, advised by molecular geneticist and physiologist Joanna Chui, professor and vice chair of the UC Davis Department of Entomology and Nematology, will speak on "Environmental and Anthropogenic Impact on Insect Gene Expression and Physiology" in 122 Briggs Hall. Her seminar also will be virtual. The Zoom link:https://ucdavis.zoom.us/j/95882849672.
Professor Chiu will introduce her. A pre-seminar coffee session is set from 3:30 to 4:10 p.m. in Briggs 158.
"Natural environmental factors and anthropogenic disturbances can modulate gene expression, resulting in alteration of organismal phenotype," Tabuloc says in her abstract. "In the first part of my thesis project, I used Drosophila melanogaster as an insect model to understand the mechanisms by which 24-hour light-dark cycles can regulate rhythmic changes in the chromatin to generate circadian rhythms of gene expression and orchestrate daily biological rhythms. I observed that two clock proteins, CLOCK and TIMELESS, regulate daily rhythmicity in the binding of BRAHMA, a chromatin remodeler, to DNA spanning clock-controlled genes to facilitate their rhythmic gene expression cycles. Moreover, because TIMELESS degrades in the presence of light, my results provide new insights into how light affects DNA structure and gene expression."
"In the second part of my thesis project, I investigated the impact of insecticide applications on the fruit pest Drosophila suzukii," Tabuloc said. "Specifically, I performed RNA sequencing analysis on D. suzukii flies that are either susceptible or resistant to common insecticides to determine genetic mechanisms underlying insecticide resistance in this agricultural pest. My results revealed that enhanced metabolic detoxification confers pyrethroid resistance while spinosad resistance is the result of both metabolic and penetration resistance. Finally, we identified alternative splicing
as an additional mechanism of resistance. These results will facilitate the development of efficient molecular diagnostics to identify insecticide resistance in the field and enable growers to adjust D. suzukii spray programs to control this devastating pest more effectively."
Christine received her bachelor of science degree in biochemistry and molecular biology from UC Davis in 2015. She joined the Chiu lab as an undergraduate research assistant in 2012. "Much of my work in the lab has involved different agricultural pests and investigating the molecular aspects contributing to the insect's ability to be an effective pest," she says on the Chiu lab website. "My current focus is to investigate the effects of climatic change on gene expression of an invasive pest and determine whether there is a correlation to resistance and survival. In addition to pest management research, I am also studying a kinase of a core clock protein in Drosophila melanogaster and hoping to dissect its functional contribution to the molecular oscillator."
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.