"The world's primary arboviral vector, Aedes aegypti, was reintroduced into California in 2013," Kelly says in her abstract. "Its re-establishment throughout the state appears to be due, in part, to the failure of pyrethroid insecticides applied for adult mosquito control. My dissertation work examines 1) population dynamics within the state 2) how mosquito metabolism is impacted by pyrethroid exposure and 3) how a pyrethroid susceptible reference strain of Aedes aegypti differs physiologically from a wild California Ae. aegypti population. This research describes a successful story of ˆexclusion and generated novel hypotheses about the physiological underpinnings of the fitness costs and tradeoffs observed in insects withthepyrethroid resistance phenotype. Additionally, I explore novel targets for insecticide synergism."
Kelly is president of the Entomology Graduate Student Association (EGSA), and served two terms as president of the UC Davis Equity in STEM and Entrepreneurship (ESTEME).
Active in the Entomological Society of America, Kelly was a member of the UC Davis team that won the national Entomology Games championship in 2022. The UC Davis team included three other doctoral candidates from the Department of Entomology and Nematology: Zachary Griebenow of the Phil Ward lab, captain; Jill Oberski of the Ward laboratory; and Madison “Madi” Hendrick of the Ian Grettenberger lab.The event is a lively question-and-answer, college bowl-style competition on entomological facts played between university-sponsored student teams. The question categories include biological control, behavior and ecology, economic and applied entomology, medical, urban and veterinary entomology, morphology and physiology, biochemistry and toxicology, systematics and evolution integrated pest management and insect/plant interactions.
Other academic highlights:
- Kelly was selected the recipient of the 2022 Student Leadership Award from the Pacific Branch of ESA, which encompasses 11 Western states, parts of Canada and Mexico and several U.S. territories. (See news story)
- She won a first-place award at the 2021 Entomological Society of America (ESA) meeting with her poster, “Metabolic Snapshot: Using Metabolomics to Compare Near-Wild and Colonized Aedes aegypti.”
Taylor, who joined the Attardo lab in 2018, holds a bachelor of science degree in biology, with a minor in chemistry, from Santa Clara University, where she served as president of the campuswide Biology Club and led STEM projects, encouraging and guiding underrepresented students to seek careers in science, technology, engineering and mathematics (STEM).
Her future plans? "I'm pursuing vector ecologist positions within California vector control programs!"
(Editor's Note: For the Zoom password, contact associate professor Geoffrey Attardo at firstname.lastname@example.org or Taylor Kelly at email@example.com.)
Her seminar takes place at 3:30 in 366 Briggs Hall, and also will be on Zoom.
Mack studies Aedes aegypti with a focus on analysis of transcriptomic datasets and 3D imaging datasets. "Throughout my time in graduate school, my projects have considered pyrethroid resistance in Aedes aegypti ;examining the genetic response to this insecticide. As I finish up my dissertation, I hope to pursue a career in industry using the skills I've developed to continue to analyze large datasets!"
Insecticide resistance is a global issue, Mack says in her exit seminar abstract. Ae. aegypti, known as "the yellow fever mosquito," can transmit dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents. The mosquito was first colonized California in 2013 and arrived resistant to pyrethroids. "The pyrethroid target site genotype differs geographically in California and partially infers resistance phenotype, indicating that other mechanisms are at play as well."
"Since their detection in 2013, Aedes aegypti has become a widespread urban pest in California," the co-authors wrote in the abstract. "The availability of cryptic larval breeding sites in residential areas and resistance to insecticides pose significant challenges to control efforts. Resistance to pyrethroids is largely attributed to mutations in the voltage gated sodium channels (VGSC), the pyrethroid site of action. However, past studies have indicated that VGSC mutations may not be entirely predictive of the observed resistance phenotype."
"To investigate the frequencies of VGSC mutations and the relationship with pyrethroid insecticide resistance in California, we sampled Ae. aegypti from four locations in the Central Valley, and the Greater Los Angeles area. Mosquitoes from each location were subjected to an individual pyrethrum bottle bioassay to determine knockdown times. A subset of assayed mosquitoes from each location was then analyzed to determine the composition of 5 single nucleotide polymorphism (SNP) loci within the VGSC gene."
"Resistance associated VGSC SNPs are prevalent, particularly in the Central Valley. Interestingly, among mosquitoes carrying all 4 resistance associated SNPs, we observe significant heterogeneity in bottle bioassay profiles suggesting that other mechanisms are important to the individual resistance of Ae. aegypti in California."
Mack, who holds a bachelor of science degree (2018) in biology from Creighton University, Omaha, Neb., enrolled in the UC Davis graduate school program in 2018.
Active in the Entomological Society of America, Mack scored second place in student competition at the 2022 joint meeting of the Entomological Societies of America, Canada, and British Columbia, held last November in Vancouver, British Columbia. She entered her presentation, "Three Dimensional Analysis of Vitellogenesis in Aedes aegypi Using Synchrotron X-Ray MicroCT,” in the category, "Graduate School Physiology, Biochemistry and Toxicology: Physiology.
Her abstract: "Traditional methods of viewing the internal anatomy of insects require some degree of tissue manipulation and/or destruction. Using synchrotron-based x-ray phase contrast microCT (pcMicroCT) avoids this issue and has the capability to produce high contrast, three dimensional images. Our lab is using this technique to study the morphological changes occurring in the mosquito Aedes aegypti during its reproductive cycle. Ae. aegypti is the primary global arbovirus vector, present on all continents except Antarctica. Their ability to spread these viruses is tightly linked with their ability to reproduce, as the production of eggs in this species is initiated by blood feeding. Amazingly, this species produces a full cohort of eggs (typically 50-100) in just 3 days' time following a blood meal. This rapid development represents dramatic shifts in physiological processes that result in massive volumetric changes to internal anatomy over time. To explore these changes thoroughly, a time course of microCT scans were completed over the vitellogenic period. This dataset provides a virtual representation of the volumetric, conformational, and positional changes occurring in tissues important for reproduction across the vitellogenic period. This dataset provides the field of vector biology with a detailed three-dimensional internal atlas of the processes of vitellogenesis in Ae. aegypti."
"As for career plans, I am applying to computational biology positions in industry," Mack said. "I'm not filing my dissertation until July so I am still working on this."
The seminar, set for 4:10 p.m., Pacific Time, will be virtual only, announced seminar series coordinator Emily Meineke, an urban landscape entomologist and assistant professor.
The Zoom link: https://ucdavis.zoom.us/j/95882849672.
His abstract: "Because they vector pathogens to humans, mosquitoes impact millions of people every year. 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."
On his website, Vinauger elaborates: "The ability of mosquitoes to detect, process, and respond to olfactory information emitted by their hosts can affect disease transmission. The magnitude of their responses to host and plant odors varies drastically throughout the day, but, despite their clear epidemiological relevance, the neural and molecular mechanisms acting at the circuit levels to control mosquito behavior remain to be determined. In the lab, we employ an interdisciplinary approach combining behavioral assays, electrophysiological recordings, transcriptomic analysis, and CRISPR/Cas9 gene editing, to characterize rhythms in odorant detection, perception, and olfactory behavior, thereby identifying the genetic basis of the temporal plasticity in mosquito-host interactions."
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."
The Vinauger lab "studies the molecular, physiological, and neural basis of mosquito behavior," according to its website. "We are a group of experimental biologists, relying 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."
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.
"The diurnal mosquitoes Aedes aegypti are vectors of several arboviruses, including dengue, yellow fever, and Zika viruses. To find a host to feed on, they rely on the sophisticated integration of olfactory, visual, thermal, and gustatory cues emitted by the hosts. If detected by their target, this latter may display defensive behaviors that mosquitoes need to be able to detect and escape in order to survive. In humans, a typical response is a swat of the hand, which generates both mechanical and visual perturbations aimed at a mosquito. Here, we used programmable visual displays to generate expanding objects sharing characteristics with the visual component of an approaching hand and quantified the behavioral response of female mosquitoes. Results show that Ae. aegypti is capable of using visual information to decide whether to feed on an artificial host mimic. Stimulations delivered in a LED flight arena further reveal that landed Ae. aegypti females display a stereotypical escape strategy by taking off at an angle that is a function of the direction of stimulus introduction. Altogether, this study demonstrates that mosquitoes landed on a host mimic can use isolated visual cues to detect and avoid a potential threat."
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, 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, France; and his doctorate in 2011 from the University of Tours, Research Institute on Insect Biology.
The UC Davis Department of Entomology seminars are held on Wednesdays through March 15. (See schedule.) Eight of the 10 will be in-person in 122 Briggs Hall, and all will be virtual.
Winokur will 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:
"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."
A doctoral student at UC Davis since 2016, Winokur is studying for her PhD in entomology with a designated emphasis in the biology of vector-borne diseases. She will submit her dissertation in October and officially graduate then, "although I participated in the doctoral ceremony in June," she related. "I will be a postdoc in the Barker lab working with VectorSurv (https://vectorsurv.org/), and also have a PacVec postdoctoral fellowship (https://pacvec.us/) to dedicate 25 percent of my time to "Enriching Practical Learning Resources for Entomological, Medical, and One-Health Curricula.'
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.
In academic leadership, Winokur co-developed a Stanford course in 2019 on "How Vector-Borne Diseases Have Shaped Human History" and co-developed a syllabus and mentored students. She also co-developed a UC Davis course (2019, 2019, 2020) with other entomology graduate students on "The Natural History of Insects." She has served as both a teaching assistant and lecturer, as well as a mentor.
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 firstname.lastname@example.org.
The Zoom seminar, open to all interested persons, will take place from 4:10 to 5 p.m. Click here for the form to obtain the Zoom link to connect.
"In this talk, we are going to demonstrate the tripartite interactions between the microbiome, mosquitoes of the genus Aedes and Zika virus that they transmit," she says. Aedes albopictus is also known as the Asian tiger mosquito.
"My research focuses on the tripartite interactions between the microbiome, mosquitoes as vectors and the arboviruses they transmit," Onyango says. "In addition, I am interested in the role the vector-host- pathogen interface plays in enhancing disease severity in the vertebrate host. The goal of my research is to develop innovative control mechanisms both for the vector and pathogens they transmit."
Host is medical entomologist-geneticist Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology. Cooperative Extension specialist and assistant professor Ian Grettenberger coordinates the fall seminars.
"Dr. Maria Onyango works on the biology underlying interactions between arboviruses (Zika virus), vector mosquitoes and the associated microbiome," Attardo said.
Along with seven other scientists, Attardo and Onyango co-authored a research article in the Oct. 2nd edition of Frontiers in Microbiology on"Zika Virus Infection Results in Biochemical Changes Associated With RNA Editing, Inflammatory and Antiviral Responses in Aedes albopictus."
"Rapid and significant range expansion of both the Zika virus (ZIKV) and its Aedes vector species has resulted in the declaration of ZIKV as a global health threat. Successful transmission of ZIKV by its vector requires a complex series of interactions between these entities including the establishment, replication and dissemination of the virus within the mosquito. The metabolic conditions within the mosquito tissues play a critical role in mediating the crucial processes of viral infection and replication and represent targets for prevention of virus transmission. In this study, we carried out a comprehensive metabolomic phenotyping of ZIKV infected and uninfected Ae. albopictus by untargeted analysis of primary metabolites, lipids and biogenic amines. We performed a comparative metabolomic study of infection state with the aim of understanding the biochemical changes resulting from the interaction between the ZIKV and its vector. We have demonstrated that ZIKV infection results in changes to the cellular metabolic environment including a significant enrichment of inosine and pseudo-uridine levels which may be associated with RNA editing activity. In addition, infected mosquitoes demonstrate a hypoglycemic phenotype and show significant increases in the abundance of metabolites such as prostaglandin H2, leukotriene D4 and protoporphyrinogen IX which are associated with antiviral activity. These provide a basis for understanding the biochemical response to ZIKV infection and pathology in the vector. Future mechanistic studies targeting these ZIKV infection responsive metabolites and their associated biosynthetic pathways can provide inroads to identification of mosquito antiviral responses with infection blocking potential."
Onyango holds two degrees from the University of Nairobi, Kenya: a bachelor of science degree in biochemistry and zoology and a master's degree in applied parasitology. She received her doctorate in veterinary entomology from Deakin University and Australian Animal Health Laboratory, Commonwealth Scientific and Industrial Research Organisation (CSIRO), and then completed postdoctoral training at the Yale School of Public Health, Department of Epidemiology of Microbial Diseases.
For any technical issues regarding the seminar, contact Grettenberger at email@example.com