- Author: Kathy Keatley Garvey
"Can Genetically Modified Mosquitoes End Disease?" spotlights the work of Gregory Lanzaro, director of the UC Davis Vector Genetics Laboratory, and a professor in the School of Veterinary Medicine's Department of Pathology, Microbiology and Immunology, and his "blood brother," longtime fellow mosquito researcher Anthony "Anton" Cornel, a member of the UC Davis Department of Entomology and Nematology (ENT) faculty, director of the UC Mosquito Control Research Laboratory, and researcher in the Vector Genetics Laboratory.
The New York Times' feature, written by global health reporter Stephanie Nolen, appears in the Sept. 29 edition.
An earlier news story announcing the $10.2 million grant to the UC Davis Vector Genetics Laboratory, from Open Philanthropy, was posted Jan. 25, 2022 on the UC Davis Department of Entomology and Nematology website. In that story, Lanzaro, former ENT faculty member and former director of the now-folded UC Mosquito Research Program, explained that the research involves "the release of Anopheles mosquitoes engineered to prevent transmission of the malaria parasite Plasmodium falciparum on the islands. We are working in collaboration with the UC Irvine Malaria Initiative, a research consortium including scientists from UC Irvine, San Diego and Berkeley as well as Johns Hopkins University. We are working toward the application of advanced genetic tools aimed at the mosquito vector. It is our belief that this approach, used in conjunction with early malaria treatment and detection, can provide a cost effective, sustainable, and environmentally responsible program to ultimately eliminate malaria from Africa.”
"The malaria situation in São Tomé and Príncipe, an African island nation with a population of 200,000, epitomizes the current challenge in the global struggle against the disease," Nolen wrote. "The country is among the world's least developed, and it has depended on foreign aid to fight malaria. Various campaigns over the past 50 years drove cases down, only to have them resurge worse than ever when the benefactor moved on."
Lanzaro told Nolen that "we've been working on this for 30 years, and from the beginning we said, It has to work, but it also has to be inexpensive, and it has to be sustainable. And we believe we have it...We have got to get going. We can't just keep saying 10 more years, 10 more years. Six million people have died while we've been fiddling around.”
Cornel agrees. In the initial UC Davis news story, he commented: "The fight to reduce and possibly eliminate malaria continues and becomes especially challenging as efforts to reduce malaria morbidity have plateaued since 2015. Therefore, we must seriously consider new tools. One such tool is genetically modifying the major mosquito vector in the Afrotropics so that it cannot transmit malaria. The project aims to use genetically modified mosquito strategy to reduce and eliminate malaria from the Islands of São Tomé and Príncipe, as proof of concept, before using this technology on larger scales on mainland Africa."
The New York Times' story pointed out that "genetic modification is a controversial endeavor. Governments are hesitant, and few in Africa have laws to regulate the use of the technology. Its risks lie in the unknowns: Could the modified mosquito evolve in some way that has harmful effects on the rest of the ecosystem? Could it prompt a dangerous mutation in the malaria parasite, which will find a new way to spread to survive?"
"These fears," Nolen wrote, "are why the University of California team chose São Tomé and Príncipe for its experiment: The island nation is isolated and has limited international traffic. The team has also built in a plan to wipe out the population of its modified mosquitoes if there is a need to end the experiment for any reason."
See the entire news story, Can Genetically Modified Mosquitoes End Disease?
- Author: Kathy Keatley Garvey
The article, noting that World Mosquito Day is Aug. 20, ranks 2023's Most Vulnerable Counties to Mosquito-Borne Diseases.
"We compared nearly 800 counties based on four categories. We looked at the number of mosquito species in each state, recent cases of diseases like West Nile and Eastern equine encephalitis viruses, and mosquito-friendly climate, among 12 total metrics," author Sav Maive wrote.
The 10 most vulnerable:
- Pitt County, N.C.
- Maricopa County, Arizona
- Buncombe County, N.C.
- Brazonia County, Texas
- Liberty County, Ga.
- Jefferson County, Texas
- Knox County, Tenn.
- Cameron County, Texas
- Galveston County, Texas
- Camden County, Ga.
The group gathered data on 772 U.S.counties that reported human cases of mosquito-borne diseases from 2020 to 2022. Then they interviewed three university faculty members from California, Florida and Texas. In addition to Lawler, they were Eva Buckner of the University of Florida and Patricia Pietrantonio of Texas A&M.
Lawler's responses:
Mosquitoes are deemed the world's deadliest animal. How concerned should Americans be about the West Nile Virus, locally transmitted malaria, or other mosquito-borne diseases?
"Americans should be moderately concerned about mosquito-borne illness, to the extent of protecting themselves from bites and preventing accumulation of stagnant water where mosquitoes breed (other than natural wetlands and ponds, which will support beneficial predators). Serious mosquito-borne illness is rare in the Continental U.S.A., thanks to public and private Mosquito Abatement organizations, and certain environmental factors. However, some warm, humid regions, like Puerto Rico, American Samoa, and the US Virgin Islands are prone to outbreaks of mosquito-transmitted pathogens, such as Dengue viruses. West Nile Virus is widespread and can be harmful to those with weak immune systems. Other encephalitis-causing viruses may be more localized, but can occasionally be serious, such as Eastern Equine Encephalitis. Malaria is only found in few places in the South, but it has some capacity to spread if mosquitoes are not controlled."
What types of environments attract mosquitoes into people's homes, and how can they be avoided?
"Puddles and other wet areas that hold water for five or more days can let mosquitoes breed, because their larvae are aquatic. Avoid over-watering such that water accumulates in ditches, empty plant saucers and anything else that collects water (old tires and similar), and drain unused pools. Treehole water can support the mosquitoes that carry heartworm to pets. A hole drilled into the base of the treehole can drain it, while still leaving habitat for nesting birds. Maintain good screens on the house."
What are your top three mosquito repellent recommendations?
"I really only have two: repellents based on DEET, and lemon-eucalyptus oil. Some botanicals other than lemon eucalyptus also work, such as geraniol, but might need to be applied more often."
What are your top three tips for managing itchiness or pain from mosquito bites?
"Prevention: First, wear light-colored, long-sleeved shirts and long pants if you can, and use repellent. If bitten, you can use a topical antihistamine, or witch hazel. A band-aid can be helpful for compulsive scratchers."
What are the most concerning symptoms from mosquito bites?
"I am not a medical doctor, so the following is not official medical advice, and should not be presented as such in any context. Most of the mosquito-borne diseases take a couple of days or more to incubate. They can cause headaches and fever. Consider consulting a medical doctor if these symptoms arise in the days after bites occur. Secondary infections caused by scratching are also concerning. These are frequently indicated by discharge, excessive swelling and pain, and sometimes red streaks near the bite."
Which animal species are most vulnerable to mosquito-borne diseases? Should pet owners be worried?
"I am also not a veterinarian, so the following is not comprehensive. Owners of some kinds of pets need to be concerned about pet exposure to mosquitoes. Heartworm is carried by mosquitoes. This can affect dogs and sometimes cats. These should be vaccinated, especially where heartworm is common (most of the USA). Horses are quite vulnerable to some of the encephalitis viruses, such as West Nile Virus and Eastern Equine Encephalitis, and should be vaccinated. Pet birds can contract West Nile virus and some of the other viruses. This often isn't serious, but young birds should be protected as they may have less immunity, and outdoor aviaries should be screened."
Lawler joined the then UC Davis Department of Entomology in 1995, retiring in January 2023. She taught aquatic entomology and community entomology. Her research interests: Aquatic ecology, especially mosquitoes, other aquatic insects and amphibians; experimental studies of food webs and population dynamics; and ecosystem subsidy.
Lawler chaired the Entomology and Nematology Curriculum Committee from 2017 to 2022, and served as the lead faculty advisor of the department from 2003 to 2022. On campus, she chaired the Designated Emphasis in Biology of Vector Borne Disease (DEBVBD) from 2017 to 2020, and served on the DEBVBD Executive Committee from 2021-2022.
Lawler holds a doctorate in ecology and evolution (1992) from Rutgers University, New Brunswick, N.J. and did postdoctoral research at the Imperial College, Silwood Park, Ascot, UK, and at the University of Kentucky, Lexington.
- Author: Kathy Keatley Garvey
"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 gmattardo@ucdavis.edu or Taylor Kelly at etkelly@ucdavis.edu.)
- Author: Kathy Keatley Garvey
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."
The conclusion:
"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."
- 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.
