That's just one of the facts that UC Davis medical entomologist-geneticist Geoffrey Attardo will discuss when he presents a seminar on "The Mating Biology of Tsetse Flies--Insights into the Morphological, Biochemical, and Molecular Responses to Mating Stimuli in a Viviparous Disease Vector."
The seminar, hosted by the UC Davis Department of Entomology and Nematology, is set for 4:10 p.m., Monday, Oct. 9 in 122 Briggs Hall.
Attardo, an associate professor, UC Davis Department of Entomology and Nematology and chair of the Designated Emphasis in the Biology of Vector-Borne Diseases, is a global expert on vectorborne diseases, including his groundbreaking work on tsetse flies. He researches the invasive yellow mosquito, Aedes aegypti, which can carry such diseases as dengue, chikungunya, Zika and yellow fever.
His work involves predicting insecticide resistance and tracking movements of genetically independent populations of aegypti throughout the state.
"Research into the reproductive behavior of tsetse flies offers key insights into controlling diseases like African sleeping sickness," Attardo writes in his abstract. "Unique among insects, these flies give birth to live offspring. During mating, males transfer a mix of sperm and other vital substances to the females. This study employs state-of-the-art techniques, including 3D scanning and genetic analysis, to monitor changes in the female fly's reproductive system over a 72-hour period post-mating. Findings indicate that mating sets off a chain of intricate changes in the female, affecting everything from biochemistry to gene activity. These changes prepare her for pregnancy and childbirth. The study opens up new avenues for understanding tsetse fly biology and offers potential strategies for disease control."
The seminar also will be on Zoom. The link:
The Attardo lab monitors the dynamics of vector insects at the levels of physiology, population genetics and environmental interactions.
Attardo, who holds a doctorate in genetics from Michigan State University, where he researched the molecular biology of mosquito reproduction, joined the UC Davis Department of Entomology and Nematology in 2017 from the Yale School of Public Health's Department of Epidemiology of Microbial Diseases.
For his outstanding work, he received the 2022 Medical, Urban, and Veterinary Entomology Award from the Pacific Branch, Entomological Society of America, which encompasses 11 Western states, plus parts of Canada and Mexico, and U.S. territories.
For any technical issues regarding Zoom, contact seminar coordinator Brian Johnson at email@example.com.
The open house takes place from 1 to 4 p.m. in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus. The theme: "Household Vampires." The event will zero in on mosquitoes, fleas, ticks, lice and bedbugs. Scientists will be there to answer questions. The event is free and family friendly and parking is also free.
Who's talking about mosquitoes?
- Educators from the Sacramento-Yolo Mosquito and Vector Control District. See https://www.fightthebite.net/
- Carla-Cristina "CC" Melo Edwards, a first-year doctoral student in the laboratory of medical entomologist-geneticist Geoffrey Attardo, associate professor of entomology, UC Davis Department of Entomology and Nematology. She will share her expertise on mosquitoes and show specimens.
- Moriah Garrison, senior entomologist and research coordinator with Carroll-Loye Biological Research (CLBR). She is scheduled to show live ticks and mosquitoes and field questions.
- Nazzy Pakpour, UC Davis alumna, Novozymes scientist and author of Please Don't Bite Me
Professor Attardo, who maintains a lab website on Vector Biology and Reproductive Biology at http://attardo-lab.com, and chairs the Designated Emphasis in the Biology of Vector-Borne Diseases, will display some of his mosquito images, including a blood-fed Aedes aegypti, and a female and male Culex tarsalis. (A prior commitment prevents him from being at the open house the entire time.) One or more images by Alex Wild, a UC Davis doctoral alumnus and curator of entomology, University of Texas, Austin, also will be featured.
Breaking news? The Aedes aegypti mosquito, which can transmit such diseases as Zika, yellow fever, dengue, chikungunya and others, was detected Sept. 11 in Dixon. "The mosquito may be active around dusk and dawn but bites most often during the day and often bites indoors," said Richard Snyder, Solano County Mosquito Abatement District manager, in a news release.
The Sacramento-Yolo Mosquito Vector Control District recently announced two fatalities in Sacramento and Yolo counties due to West Nile virus. "In addition to these deaths, currently there are 10 other human cases in Sacramento County and 8 in Yolo County. Since there won't be a significant decline in mosquito populations until mid-October, more human cases will likely be reported."
UC Davis distinguished professor Lynn Kimsey, director of the Bohart Museum and UC Davis forensic entomologist Robert Kimsey will be among the presenters on other "household vampires."
Attendees can see the Bohart's butterfly collection, curated by entomologist Jeff Smith, and get acquainted with critters in the live insect petting zoo.
The family arts and crafts activity will feature collecting activities. Participants are asked to bring a recycled jar. "This should be a clean and dried glass jar with a wide, metal top--think jam, pickle, peanut butter jars. Four to 16-ounce jars work well," said Tabatha Yang, education and outreach coordinator. "We will have some on hand as well, but recycling is good! We will fill the bottom with plaster of paris and let it dry and teach people how to use it properly, using something like nail polisher remover containing ethyl acetate as the killing agent. A UC Davis Department of Entomology and Nematology video explains the procedure: https://youtu.be/s8yCzFGzbn8?si=71sNmA5l8NyP1zj0
For more information, email firstname.lastname@example.org
Fleas? Ticks? Bed bugs? Mosquitoes?
The Bohart Museum of Entomology will host an open house, themed "Household Vampires," from 1 to 4 p.m., Saturday, Sept. 23 in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus. It's free and family friendly. Parking is also free.
One of the presenters ready to answer your questions about mosquitoes is Carla-Cristina "CC" Melo Edwards, a first-year doctoral student in the laboratory of medical entomologist-geneticist Geoffrey Attardo, associate professor of entomology, UC Davis Department of Entomology and Nematology, who also specializes in reproductive physiology and molecular biology.
In the Attardo lab, Edwards focuses her research "on investigating the physiological mechanisms underlying pyrethroid resistance in Aedes aegypti (the yellow fever mosquito)."
She was a McNair scholar at Baylor University, where she completed her undergraduate degree in cell and molecular biology in May 2021. "I got interested in the mosquito field through my undergraduate research of studying the sensory and oviposition responses of Aedes aegypti in relation to the compound geosmin," Edwards related.
"When I am not in the lab, I enjoy getting involved with my local community by helping out and doing outreach," Edwards said. This past summer she helped the city of Lubbock, Amarillo, and the Texas Public Health Department by identifying mosquitoes for West Nile surveillance. She also served as the outreach chair for the Texas Tech Association of Biologists during her masters' degree pursuit and enjoyed being a mentor for first-generation students.
"In my free time, I like getting coffee with my friends, running (currently training for the California International Marathon), and trying new crafts and recipes."
Attardo will be displaying images of mosquitoes. An image of mosquito larvae by UC Davis doctoral alumnus and macro photographer Alex Wild, curator of entomology at the University of Texas, also will be displayed.
Open house attendees can view the butterfly specimen collection, curated by entomologist Jeff Smith, and get acquainted with live Madagascar hissing cockroaches and stick insects, part of the Bohart Museum's insect petting zoo. A family arts-and-crafts activity is also planned.
The Bohart Museum, founded in 1946, houses a global collection of eight million insect specimens. It also maintains an insect-themed gift shop. UC Davis distinguished professor Lynn Kimsey, a UC Davis alumna, directs the museum.
Alarm bells went off. Scientists joined forces to target the mosquito and stop it from spreading throughout the state.
Enter the UC Davis laboratory of medical entomologist-geneticist Geoffrey Attardo, associate professor, UC Davis Department of Entomology and Nematology.
And now, enter the exit seminar of doctoral candidate Erin "Taylor" Kelly of the Attardo lab.
She'll present a seminar on "Investigating the Metabolic Underpinnings of Pyrethroid Resistance in California Aedes aegypti" at 3:30 p.m., Thursday, June 8 in 366 Briggs Hall and also on Zoom.
"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."
UC Davis medical entomologist Anthony Cornel, who leads the Mosquito Control Research Laboratory in Parlier, works with Taylor on insecticide resistance in mosquitoes. “Taylor's PhD project is challenging as she endeavors to tease apart the biochemical and genetic factors that cause resistance to some commonly used insecticides to control Aedes aegypti," wrote Cornel, a member of the UC Davis Department of Entomology and Nematology faculty. "Ae. aegypti is considered the second most dangerous insect worldwide because of its role in transmission of dengue, yellow fever, Zika and Chikungunya viruses which cause considerable morbidity and mortality. Hence, it is an important organism to study especially to eventually improve measures to control this mosquito."
Active in leadership activities and the Entomological Society of America, 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). She 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 highlights of her years pursuing a doctorate at UC Davis include:
- She 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.”
Kelly, 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!"
Infected Ae. aegypti mosquitoes can transmit dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents.
Mack will present her exit seminar on "Genetic and Molecular Factors Influencing Pyrethroid Response in Aedes aegypti from California" at 3:30 p.m., Tuesday, June 6 in 366 Briggs Hall. It also will be on Zoom.
Mack studies Ae. 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 Ae. 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. 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."
Mack is the co-lead author (with doctoral candidate Erin Taylor Kelly of the Attardo lab) of Frequency of Sodium Channel Genotypes and Association with Pyrethrum Knockdown Time in Populations of Californian Aedes aegypti, published in March 2021 in the journal Parasites and Vectors. The eight co-authors, in additioin to Attardo, included Anthony Cornel, Mosquito Control Research Laboratory, Kearney Agricultural Center, and Department of Entomology and Nematology.
"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."