- Author: Kathy Keatley Garvey
Enter molecular geneticist and mosquito researcher Clément Vinauger, an assistant professor with the Department of Biochemistry, Virginia Polytechnic Institute and State University (aka Virginia Tech), Blacksburg Va., who will present a virtual seminar hosted by the UC Davis Entomology and Nematology on "Neural and Molecular Basis of Mosquito Behavior" on Wednesday, Jan. 11.
His seminar, open to all interested persons, begins at 4:10 p.m. (Pacific Time). The Zoom link: https://ucdavis.zoom.us/j/95882849672.
"Because they vector pathogens to humans, mosquitoes impact millions of people every year," Vinauger says in his abstract. "The global strategy for the management of mosquito-borne diseases involves controlling vector populations, to a large extent, through insecticide application. However, vector-borne diseases are now resurgent, largely because of rising insecticide resistance in vector populations and the drug resistance of pathogens. In this context, the Vinauger Lab studies the molecular, physiological, and neural basis of mosquito behavior. We rely on a collaborative, integrative, and multidisciplinary approach, at the intersection between data science, neuro-ethology, molecular biology, and chemical ecology. Our long-term goal is to identify targets to disrupt mosquito-host interactions and reduce mosquito-borne disease transmission."
Molecular geneticist and physiologist Joanna Chiu, professor and vice chair of the Department of Entomology and Nematology and a Chancellor's Fellow, will serve as the host. "I have very high regard for Dr. Vinauger's integrative and multidisciplinary research into the biochemical and neurophysiological basis of insect behavior," Professor Chiu said. "His research program is innovative and rigorous, leveraging techniques in quantitative behavioral analysis, bioengineering, neurobiology, and computational methods to address exciting and important questions in mosquito biology and behavior."
You may have read about Vinauger's work, including the sleep-deprivation research that he and his lab did. Deprive mosquitoes of their sleep and that "may affect mosquitoes' ability to find human hosts or even stop their ability to spread disease," according to an article published Oct. 5, 2022 by Virginia Tech in announcing that he received a two-year $430,000 grant from the National Institutes of Health "to research the sleep habits of mosquitoes with the thought that if sleep-deprived humans have trouble functioning, maybe sleep-deprived mosquitoes do too."
"Vinauger is collaborating with a team from the University of Cincinnati in this research, the first of its kind to study how sleep deprivation may affect a mosquito's ability to find human hosts or even stop its ability to spread disease," writer Mary Hardbarger related. "A good or bad night's sleep can define a person's day, and the same goes for mosquitoes," she wrote. "In humans, a good night's rest improves memory, immunity health, energy level, and many other functions that contribute to overall well-being."
"Unfortunately, solid sleep is just as helpful to the mission of mosquitoes," she pointed out. "The more sleep they get, the more likely they are to buzz, bite, and spread disease. Fortunately, though, sleep-deprived mosquitoes are just as miserable as the sleep-deprived humans they hunt."
The Vinauger lab's latest publication, "Visual Threats Reduce Blood-Feeding and Trigger Escape Responses in Aedes aegypti Mosquitoes," appears in the Dec. 9, 2022 edition of Scientific Reports.
Jason Bittel of the Washington Post wrote about Vinauger's work in a Kids' Post, "Ever Wonder How Mosquitoes Find You?" published Aug. 5, 2019.
"Mosquitoes don't just use one sense to look for dinner," Bittel wrote. "They have evolved a sort of Swiss Army knife of tools that tells them when fresh blood is close by."
Vinauger told him: “The first thing is that they smell us."
Thinking outside the box, Vinaguer and his lab created tiny plastic helmets for the mosquitoes and gathered images from the brain into how they think.
"...when a mosquito gets a whiff of carbon dioxide, the smelling part of its brain begins to send messages to the visual part telling it to be on the lookout for food," Bittel wrote.
Apparently, a whiff and you're it, you're the food.
Vinauger joined the Virginia Tech faculty in October 2017, after serving as a postdoctoral research associate at the University of Washington, Seattle. Educated in France, earning three degrees there, he received his bachelor of science degree in biology/biological sciences in 2006 from the University of Orléans; his master's degree in 2008 from the University of Tours; and his doctorate in 2011 from the University of Tours, Research Institute on Insect Biology.
Vinauger's seminar is the first in a series of winter seminars hosted by the UC Davis Department of Entomology seminars on Wednesdays through March 15. (See schedule.) Eight of the 10 will be in-person in 122 Briggs Hall, and all will be virtual.
- Author: Kathy Keatley Garvey
Winokur, a UC Davis doctoral candidate and vector-borne disease specialist who studies with major professor Chris Barker, will present her exit seminar, hosted by the UC Davis Department of Entomology and Nematology, at 4:10 p.m., Wednesday, Oct. 5 in 122 Briggs Hall.
She'll discuss "Temperature Drives Transmission of Mosquito-borne Pathogens: Improving Entomological Estimates for Aedes aegypti-borne Virus Transmission Risk." Her seminar will be both in-person and virtual. The Zoom link: https://ucdavis.zoom.us/j/95882849672.
"The mosquito Aedes aegypti is the primary vector of a range of viruses that cause a major burden on human health worldwide, including dengue, Zika, chikungunya, and yellow fever viruses," Winokur writes in her abstract. "As the Zika epidemic emerged in 2016, estimates for Zika risk were based on proxy evidence from closely related dengue virus. To improve risk estimates, we studied how temperature affects Zika virus extrinsic incubation period. We sought to further improve risk estimates by studying thermal preferences of Ae. aegypti mosquitoes in the laboratory and in the field. Current mosquito-borne pathogen risk models primarily use temperatures from weather stations or thermal imagery as a proxy for the temperatures mosquitoes experience, however such approaches do not account for local environments or microclimates available to adult mosquitoes. Taken together, the results of these studies can be used to improve prediction of mosquito-borne pathogen risk and inform mosquito control decisions." (See information on the mosquito on the California Department of Public Health website)
Olivia received her bachelor's degree in May of 2015 from Cornell University where she was an interdisciplinary studies major (environmental effects on human health).
At UC Davis, Winokur served as the 2019-2020 president of the Entomology Graduate Student Association and as a 2020-2022 committee member of the UC Davis Entomology Diversity, Equity, Inclusion, & Belonging. She co-founded the Girls' Outdoor Adventure in Leadership and Science (GOALS) in 2017 and continues to serve in leadership roles. GOALS is a free two-week summer science program for high school girls and gender expansive youth from backgrounds underrepresented in STEM fields. They learn science, outdoors skills, and leadership hands-on while backpacking in Sequoia National Park.
Active in the vector-borne disease community, Winokur completed a 2019-2020 term as the Executive Council student representative for the American Committee on Medical Entomology (ACME) and as a 2017-2019 volunteer with the Vector-Borne Disease Section of the California Department of Public Health, where she assisted with hantavirus and plague surveillance. She peer-reviews manuscripts for the Journal of Medical Entomology.
Winokur is the recipient of numerous fellowships and grants, including a $140,00 National Science Foundation Graduate Research Fellowship; a $30,000 Pacific Southwest Center of Excellence in Vector-Borne Diseases Graduate Fellowship; a $25,000 Pacific Southwest Center of Excellence in Vector-Borne Diseases Postdoctoral Fellowship; a Professors for the Future Fellowship (UC Davis) of $3,000; and two-consecutive Hazeltine Student Research Awards (UC Davis), totaling $5,500. She also received an American Geophysical Union Centennial Grant of $9,720 and an American Association for University Women Community Action Grant of $5,000 (outreach grants).
Winokur's latest peer-reviewed publications include co-authoring "The Influence of Vector-borne Disease on Human History: Socio-Ecological Mechanisms" in the journal Ecology Letters; and serving as the lead author of "Impact of Temperature on the Extrinsic Incubation Period of Zika Virus in Aedes aegypti in the journal PLOS (Public Library of Science): Neglected Tropical Diseases.
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 technical difficulties with Zoom, contact Meineke at ekmeineke@ucdavis.edu.
- Author: Kathy Keatley Garvey
She's hoping she can trick Culex pipiens, the Northern house mosquito, into not biting us.
As a recent OSU article on Can We Trick Mosquitoes So They Stop Biting Us? explained:
"In her lab, Meuti employed a technique called RNA interference. She injected several thousand Culex pipiens mosquitoes with double-stranded RNA. (RNA stands for ribonucleic acid, which can serve as a messenger, carrying genetic information from the DNA inside an organism's cells and allowing it to be made into the proteins that do all the work.)
"The double-stranded RNA that she injected into the mosquitoes prevented a specific protein that governs the mosquitoes' circadian rhythms from being made.
"Then Meuti waited. She hoped to see if reducing the amount of a circadian clock proteins had any effect on the mosquitoes' ability to measure seasonal time. Specifically, she wanted to see if she could convince a mosquito that it was winter when it was really summer — and vice versa."
Did it work? Yes.
Her presentation begins at 4:10 p.m., Pacific Time. The Zoom link: https://ucdavis.zoom.us/j/99515291076
"Northern house mosquitoes, Culex pipiens, transmit West Nile virus to birds and people in the United States," Meuti says in her abstract. "However, transmission is limited to a few months of the year when female mosquitoes are actively biting and reproducing. During autumn, females of Cx. pipiens enter a physiologically dynamic but arrested state of development known as diapause where they divert resources from reproduction to survival."
Meuti and members of her lab study (1) how mosquitoes are able to measure daylength and whether the circadian clock is involved and (2) how human-mediated changes to the environment, like light pollution and higher temperatures in urban heat islands, affect mosquito seasonality, and how this might affect disease transmission in cities.
Meuti holds three degrees from OSU: dual bachelor degrees in microbiology and entomology, 2008; and her doctorate in entomology, 2014. Studying with major professor David Denlinger, she completed her dissertation on "Circadian Clocks and Photoperiodic Diapause in the Northern House Mosquito, Culex pipiens: Search for the Missing Link.”
Prior to joining the OSU faculty, Meuti served as a visiting professor in the Department of Biology, Kenyon College, Gambier, Ohio, in 2015-16.
"Many of us intuitively recognize that our mosquito problems are seasonal; there are times of the year when mosquitoes are abundant and we cannot go outside without getting bitten (e.g. late spring and summer), while there are other times when we enjoy a reprieve from mosquito bites (e.g. late fall and winter)," Meuti writes on her website. "I am interested in how precisely mosquitoes are able to tell what time of year it is and appropriately respond to their environment. Members of my lab group study how circadian clock genes might allow mosquitoes to measure day length to determine the time of year; how male mosquitoes change their accessory gland proteins to influence female behavior and physiology; and whether mosquitoes in urban environments are active for longer periods during the year and/or bite humans more frequently. We use a variety of molecular, genetic and physiological techniques to investigate these questions. Our ultimate goal is to uncover specific ways to manipulate seasonal responses in insects so that we can more effectively control them." (Watch Megan Meuti's Discovery Talk)
Meuti recently co-authored research, "Artificial Light at Night Alters the Seasonal Responses of Biting Mosquitoes," published in the Journal of Insect Physiology.
The abstract:
"Urban light pollution caused by artificial light at night (ALAN) profoundly affects the ecology, behavior, and physiology of plants and animals. Further, this widespread environmental pollutant has the potential to negatively impact human and animal health by changing the seasonal dynamics of disease-transmitting insects. In response to short days, females of the Northern house mosquito enter an overwintering dormancy, or diapause. While in diapause, female mosquitoes divert energy away from reproduction, cease blood-feeding, and no longer transmit disease. We demonstrate that exposure to dim ALAN (~4 lx) causes female mosquitoes to avert diapause and become reproductively active, as these females acquired less fat content, developed larger egg follicles, imbibed vertebrate blood, and produced viable eggs and larvae. Our findings suggest that mosquitoes in highly light-polluted areas such as cities may be actively reproducing and biting later in the season, thereby extending the period of disease risk for urban residents. Our results suggest that ALAN should be considered when modeling mosquito abundance, disease risk, and when deciding how long mosquito surveillance and control should persist in temperate regions."
Active in the Entomological Society of America, Meuti received the 2018 Early Career Professional Teaching Award of $1,000. She earlier won a 2008-2014 OSU fellowship, the Susan D. Huntington Dean's Distinguished University Graduate Fellowship of $67,200; and a 2010-2013 National Science Foundation Graduate Research Fellowship of $90,000.
Coordinator of the UC Davis seminars is nematologist Shahid Siddique, assistant professor. For technical issues involving the seminar, contact him at ssiddique@ucdavis.edu.
- Author: Kathy Keatley Garvey
By Geoff Attardo
Assistant Professor of Entomology and Nematology at UC Davis
California's changing climate is creating a myriad of public health concerns. Wildfires, intense heatwaves, and a drought are the most readily apparent. However, increasingly temperate winters are also facilitating the spread of invasive disease-spreading mosquitoes throughout the state. Just as our fire authorities need a robust set of tools to address wildfires, it is critical that mosquito control and public health professionals have a wide range of tools to protect Californians from mosquito-borne diseases.
The growing presence of Aedes aegypti mosquitoes, which can transmit the viruses that cause Zika, dengue, chikungunya, and yellow fever as well as the parasite that causes heartworm in pets, is a major public health threat. In 2013 this invasive species was detected in the Central Valley and has been found in California every year since. These mosquitoes cohabitate with humans and often hitchhike facilitating their spread.
Aedes aegypti lay eggs in flowerpots, water storage containers or anything capable of holding small amounts of water. Part of the problem, as highlighted in our research in Frontiers in Tropical Diseases, is that these mosquitoes have cryptic breeding sites in residential areas where mosquito control agencies can't easily inspect and treat.
In addition, their eggs can dry out and then hatch when rehydrated. In fact, when Aedes aegypti were detected in 2014 in the city of Exeter there was a large eradication effort. The effort appeared successful, as they were no longer detectable in 2015. Yet, the mosquitoes were detected in Exeter again in 2018. The unique biology of this invasive species has allowed it to expand its geographical range and today they are present in more than 300 cities in California.
Another key factor is their inherent resistance to a class of insecticides called pyrethroids, which have been a mainstay for adult mosquito control because they have low toxicity to humans and other animals. Work from our lab and the California Department of Public Health found increasing insecticide resistance in these mosquitoes (Parasites and Vectors) which limits the ability of mosquito control agencies to act against adult mosquitoes in a time of crisis.
In order to protect public health, mosquito control agencies need effective tools in their toolbox. One innovative approach takes advantage of the fact that male mosquitoes do not bite; only female mosquitoes bite and can spread viruses. This approach works by releasing sterile male Aedes aegypti mosquitoes. These male-only mosquitoes carry a self-limiting gene that prevents their female offspring from surviving. When they mate with females, this reduces the abundance of biting females in the next generation. One of the benefits of this species-specific approach is that it only targets the Aedes aegypti mosquito. This means that wildlife, such as butterflies and bees, are unharmed.
The public health threat of Aedes aegypti cannot be overstated. The World Health Organization (WHO) estimates that dengue fever causes approximately 40,000 deaths a year and Zika virus, of which there were over 5,100 symptomatic domestic cases in 2016, is known to cause serious birth defects and miscarriage as well as Guillain-Barré syndrome. The WHO also said “the potential public health benefit of practical and effective new tools to reduce or even eliminate diseases such as malaria and dengue is clear and widely recognized.”
A company called Oxitec is working with government agencies to bring its innovative mosquito control technology to the U.S. In August, they announced they are seeking regulatory approvals to expand their pilot program to bring their Friendly™ Aedes aegypti technology to California. I encourage regulators to allow the company to work with mosquito control agencies to determine the technology's effectiveness in California.
It's clear that we need efficient mosquito control tools, and we cannot wait until we have a public health emergency to act. As we have seen with the COVID pandemic it is critical to have an infrastructure in place, especially one that includes innovative – and proven – technologies, to help public health and mosquito controls stay ahead of the curve.
- Author: Kathy Keatley Garvey
She's been making her mark in all three since enrolling in 2016 in the UC Davis Department of Entomology and Nematology's Ph.D. program, with a designated emphasis in the biology of vector-borne diseases.
Winokur, who studies with major advisor Christopher Barker, associate professor, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, is a newly selected fellow of Professors for the Future (PFTF).
This is a program sponsored by UC Davis Graduate Studies “to recognize and develop the leadership skills of outstanding graduate students and postdoctoral scholars who have demonstrated their commitment to professionalism, integrity, and academic service.”
As a fellow, she will receive a stipend of $3000. Traditionally, approximately 12 fellows annually are selected to participate in the yearlong program, launched in 1992.
The PFTF program is designed to prepare UC Davis doctoral students and postdoctoral scholars “for an increasingly competitive marketplace and a rapidly changing university environment,” according to PFTF co-directors Ellen Hartigan-O'Connor, acting associate dean of UC Davis Graduate Studies, and Teresa Dillinger, academic administrator.
During the year, the fellows will receive formal training-in-teaching methods and course design; participate in a seminar course on ethics and professionalism, and meet regularly for roundtable panel discussions to promote their professional development, intellectual growth and leadership skills, the directors said.
The fellows will work on projects of their own design to enhance their graduate or postdoctoral experience and professional development of their colleagues. They summarize their projects in end-of-the-year reports. (See 2019-2020 fellows.)
Winokur titled her successful proposal, “Addressing Financial Barriers to Participation in STEM (Science, Technology, Engineering and Mathematics).”
“Graduate students perform many roles as researchers, mentors, educators, communicators, service leaders, and humans,” wrote Winokur, who is president of the UC Davis Entomology Graduate Student Association. “Financial insecurity affects students' abilities to perform these roles well, and provides a leg up to students with financial support beyond a graduate student stipend. We know that diversity is important in academia; cultivating talent from folks across the social spectrum leads to innovative and appropriate solutions.”
“Addressing financial barriers to participation in STEM graduate programs will lead to more diverse and inclusive programs,” she wrote. “Further, financial insecurity affects those who enters graduate school in the first place; research experience is often required to be considered for acceptance into graduate school, which unfortunately is often offered in the form of unpaid research internships. This can filter out low-income students early, making academia even more elite than it already is.”
Winokur will collaborate with existing resources on campus to set up a series of workshops to address the issues, focusing on three points: (1) creative ways to fund your research (2) how to support your research mentees—why unpaid labor filters low income and other disadvantaged students, and (3) making your teaching cheaper—how to make education more accessible for low-income and other disadvantaged students.
“I've been interested in applying to the Professors for the Future program for a couple years,” she said. “This year, I feel that I am at a good point in my graduate career to develop my skills through the PFTF coursework and to contribute to the graduate student community through a PFTF project.”
Since 2016, the UC Davis doctoral student has developed her teaching, mentoring, course development, and leadership skills through various courses and programs, “which has led to a basic understanding of my teaching philosophy and pedagogy.” She aims to develop her skills to “further align with my core values of diversity, equity, and inclusion in the classroom and laboratory.”
Olivia grew up in Laguna Niguel, Calif. where she focused on science at the Dana Hills High School Health and Medical Occupations Academy. She holds a bachelor's degree, 2015, from Cornell University, where she majored in interdisciplinary studies, focusing on the environmental effects on human health. While at Cornell, she worked as an intern for the National Institutes of Health, working on climate change initiatives for the National Institute of Environmental Health Sciences and the Fogarty International Center.
Winokur holds a National Science Foundation Graduate Research Fellowship. She is a two-time recipient of the Bill Hazeltine Memorial Research Award, given annually to an outstanding UC Davis graduate student studying vector-borne diseases.
Winokur, who researches Aedes aegypti mosquitoes, is the co-author of research published in several journals, including PLOS Neglected Tropical Diseases. Her first first-author paper, “Impact of Temperature on the Extrinsic Incubation Period of Zika Virus in Aedes aegypti” was just published in March.
Since 2017, she has served as a volunteer with the California Department of Public Health's Vector-Borne Disease Section, assisting with hantavirus and plague surveillance by rodent trapping and testing.
Winokur mentors undergraduate students in the UC Davis Research Scholars Program in Insect Biology (RSPIB), founded and directed by faculty members Jay Rosenheim, Joanna Chiu and Louie Yang, UC Davis Department of Entomology and Nematology.
Active in STEM projects, Winokur co-founded GOALS (Girls' Outdoor Adventure in Leadership and Science) in 2017, a program that develops and runs free two-week summer science programs for high school girls and gender expansive youth from backgrounds underrepresented in STEM fields. The girls learn science, outdoor skills and leadership hands-on while backpacking in Sequoia National Park.
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