- Author: Kathy Keatley Garvey
A member of the Microbiology Graduate Group and the laboratory of community ecologist Rachel Vannette, associate professor and vice chair of the UC Davis Department of Entomology and Nematology, he will deliver the Merton Love seminar from 3 to 4:30 p.m., Friday, May 24 in Room 1230 of Walker Hall.
The award memorializes Robert Merton Love (1909-1994), emeritus professor of agronomy and range science, who served on the UC Davis faculty from 1940-1976.
“Shawn's thesis work spans microbiology, ecology and evolutionary biology, combined with careful natural history, to document novel species interactions between hosts and microbial communities,” said Vannette, who nominated him for the award. “Each chapter has broad implications for the ecology and evolution of host-microbe interactions. Shawn's work has already reframed the conditions under insect-microbe interactions are thought to hold relevance and evolve. His research has highlighted the utility of natural history observations of microbes and sampling understudied life history stages (overwintering developing insects).”
“Overall, Shawn's dissertation is an example of how detailed observations combined with fearless experimental dissection of interesting phenotypes can yield novel descriptions of species interactions that change the field's perception of when and where microbial communities are important,” she said.
“Shawn's first chapter describes adaptations of a flower specialist bacteria to acquiring resources from pollen—a nutrient source specific to flowers,” Vannette said. “Our lab was interested in the ecology of the flower-dwelling bacteria Acinetobacter, but Shawn took a new look at this bacterium, examining its growth morphology in nectar and in association with pollen. He noticed that this bacterium co-localized with pollen and grew exponentially more in the presence of pollen. To explore this phenotype, he designed new media and assays (microwaving pollen) to determine that Acinetobacter benefits the most from live pollen via stimulating pollen to germinate (within minutes!), then digesting it. Shawn then designed a series of experiments to examine if this ability was unique to this bacterial clade or shared among many floral microbes (it seems to be specific to Acinetobacter).”
“He collected brood cells (nectar and pollen balls along with developing larvae) from these locations at multiple points through bee development and examined not only the bacteria and fungal community composition through insect development, but also examined changes in microbial abundance at each life stage,” Vannette said. “In contrast to my (and the literature's) predictions, Shawn showed that microbial abundance peaks during larval overwintering, when solitary bees and other holometabolous insects are predicted to have voided their microbial gut communities. Instead, healthy A. bomboides hosts the highest abundance of fungi and bacteria during the fall—a wet season where pathogen abundance is also highest.”
Christensen received accolades and widespread media coverage for the first chapter of his dissertation, “Nectar Bacteria Stimulate Pollen Germination and Bursting to Enhance Microbial Fitness,” published in July 2021 in Current Biology. His second thesis chapter on the microbes associated with Anthophora bomboides, has just been accepted for publication by the International Society of Microbial Ecology (ISME).
And more good news: Christensen is a" co-principal investigator on a newly awarded grant by JGI to sequence the genome of the yeast," Vannette said, "and explore its functional potential in renewable energy and is applying to continue to leverage this system's potential in antifungal chemistry and evolution of pathogen defense.”
Every time we see the nests of Anthophora bomboides stanfordiana on the sand cliffs at Bodega Head, we think of the scientists, including Shawn Christensen and Rachel Vannette, who study them. The late Robbin Thorp, UC Davis distinguished emeritus professor, UC Davis Department of Entomology and Nematology, researched them decades ago.
Check out PBS' Deep Look video, "This Bee Builds Sandcastles at the Beach," and you'll never go to Bodega Bay without thinking of these digger bees.
- Author: Kathy Keatley Garvey
Being bothered by mosquitoes and troubled about the risk of diseases?
Mosquitoes are not just annoying. They can be deadly.
The seminar, titled "Natural Mosquito Control," is part of the California Farm Academy Speaker Series, and will take place from 4:30 to 7:30 p.m. at CLBL, located at 40140 Best Ranch Road, Woodland. The event begins with pizza and mingling, “until about 5:30, and then the presentation,” said spokesperson Julia Hobbs Thomas. Reservations can be made on Eventbrite.com at this link.
The event is billed as "a discussion about both native and invasive species, what diseases they can spread, and how healthy ecosystems can create habitats that keep them in check. Agriculture can play a big role, because pesticide use can damage populations of beneficial insects like dragonflies. You'll also pick up a few tips to avoid being bitten!"
Wood-fired pizza and beverages will served beneath the canopy of a century-old valley oak, she added. Attendees can also bring food or beverages to enjoy or share.
Said Attardo: “I will be focusing on educating people about the most imminent risks of mosquito-borne diseases in California coming from West Nile Virus—due to native Culex mosquitoes predominantly—and Aedes aegypti vectored diseases such as dengue, Zika, Chikungunya, and yellow fever. I'll discuss places these mosquitoes breed in suburban and urban habitats, as well as ways people can eliminate and prevent creation of breeding sites.“
Attardo specializes in medical entomology, reproductive physiology, molecular biology and genetics. He recently hosted a UC Davis symposium, sponsored by the Deaprtment of Entomology and Nematology and the Pacific Southwest Center of Excellence in Vector-Borne Diseases, on “Tule and Cattail: A Tale of the Marsh Economy and Its Role in Human Health and Wellbeing” that aimed "to advance the land management aims of local tribal communities and provide a platform to educate about the importance of maintaining wetland biology for climate change, ecological and human health, and vector control." Attardo addressed the symposium with collaborator Diana Almendariz, a traditional ecological knowledge specialist and a cultural practitioner of Maidu/Wintun, Hupa/Yurok traditions, heritage, and experiences.
A global expert on vectorborne diseases, and renowned for his groundbreaking work on tsetse flies, Attardo received the Medical, Urban, and Veterinary Entomology Award in 2022 from the Pacific Branch, Entomological Society of America. (See news story)
He joined the UC Davis Department of Entomology and Nematology in 2017 from the Yale School of Public Health, where he served as a research scientist studying the reproductive biology of tsetse flies. Attardo holds a doctorate in genetics (2004) from Michigan State University, studying with Alexander Raikhel.
For more information on the May 15 seminar, contact Thomas at julia@landbasedlearning.org or 415-271-0090.
- Author: Kathy Keatley Garvey
Chow, an associate professor in the Department of Human Genetics, University of Utah, will discuss "Flying to the Clinic: Drug Repurposing Screen for Rare Diseases" at 4:10 p.m. in 122 Briggs Hall and also via Zoom.
The Zoom link:
https://ucdavis.zoom.us/j/9 5882849672
"Dr. Chow's research has made a tremendous impact on the lives of patients with rare diseases as well as their families and caretakers," said molecular geneticist and physicist Joanna Chiu, professor and chair of the Department of Entomology and Nematology. "His research program provides a shining example of how one can leverage many of the advantages of the Drosophila fly model to investigate molecular mechanisms disrupted in human diseases and efficiently translate that to medical interventions andFDA-approved drugs." The Chiu lab is hosting the seminar.
Professor Chow says in his abstract: "Our lab is focused on understanding the role of genetic variation on disease outcomes. We employ quantitative and functional tools, in a variety of model organisms, to study how genetic variation impacts basic cellular traits important to human health. Our work in model organisms will help to model and inform studies of genetic variation in the human population. We hope to identify variation that can lead to more precise, personalized therapies, especially for rare disease."
He and his research team "leverage the powerful genetic tools available in the fruit fly (Drosophila melanogaster) to build and study models of rare diseases," according to research news published on the University of Utah website. "The Chow lab has developed a fly model of NGLY1 deficiency, providing many new insights into the biology underlying this devastating autosomal recessive, genetic disorder."
"Using the fly model, the Chow lab discovered NGLY1 deficiency results in the absence of a sugar known as GlcNAc, which is important for different cellular processes," Martha Davis wrote in the news story. "When provided with a dietary GlcNAC supplement, flies with NGLY1 deficiency are healthier and live longer, suggesting this supplement may help NGLY1 patients...The Chow lab hopes to continue to translate basic science research of rare diseases to the clinic. The generosity of donors like the Might Family make this type of work possible. The Might family supports this research in hope that someday a treatment, or even a cure, will be found for NGLY1 deficiency."
Chow expanded on his fruit fly research on a University of Utah website heralding Academia in Action: Treating Patients as Individuals. "Because the fruit fly is small, cheap and fast, we can do massive experiments that people in mouse labs can only dream of. We take a model of a particular rare disease, and we cross it into a couple hundred different genetic backgrounds in the flies. What that gives us is basically a number of fly strains that you can think of as different individuals with different genetic backgrounds, all with the same disorder.”
D. melanogaster is widely used for biological research in genetics, physiology, microbial pathogenesis, and life history evolution. "As of 2017, six Nobel Prizes have been awarded to drosophilists for their work using the insect," according to Wikipedia.
Chow received his bachelor's degree in biology, neurobiology and behavior from Cornell University in 2003. He completed his Ph.D. in human genetics in 2008 in the Department of Human Genetics at the University of Michigan, where he worked with Miriam Meisler. He completed his postdoctoral training as a co-mentored postdoc with Andy Clark and Mariana Wolfner at Cornell University.
For any technical Zoom issues, contact seminar coordinator Brian Johnson at brnjohnson@ucdavis.edu. The full list of spring seminars is here.
- Author: Kathy Keatley Garvey
Of course!
Marielle Simone Hansel Friedman, a second-year doctoral student in the lab of urban landscape entomologist Emily Meineke, UC Davis Department of Entomology and Nematology, got swept in the Barbie movie craze last year--like so many others--so this year she decided to do something special for the Entomology Graduate Student Association (EGSA) T-shirt booth at the 110th annual UC Davis Picnic Day.
She designed a pink Barbie "Bugbie" t-shirt illustrated with a rosy maple moth, Dryocampa rubicunda.
EGSA not only sold them in its booth, but the students staffing the various insect, nematode and arachnid booths at Briggs Hall wore them as they greeted visitors and talked about their projects.
They also wore them at the popular cockroach races ("Run, roach, run!) and at the maggot art tables.
Briggs Hall got pinked! Indeed, it was like seeing a flock of flamingos.
And the crowd learned that moths can be pink. Rosy pink.
"I love moths," Marielle said, "and had seen photos of rosy maple moths before, and thought it would be the perfect bug to put in the Bugbie promo because of its bright pink and yellow markings and adorable face.”
ESGA sold a total of 482 shirts that day, with 60 of them Bugbie shirts, "putting it in our top three best sellers of the day!” Marielle commented.
She also designed the monarch butterfly, swallowtail butterfly, milkweed bug, and Bugbie stickers sold at Picnic Day.
Her doctoral work at UC Davis involves "exploring the role of urbanization in herbivory of non-native plants within the context of our changing climate."
Marielle recently co-authored a research article, "Biology of Immature Stages and Host Range Characteristics of Sudauleutes bosqi (Coleoptera: Curculionidae), a Candidate Biological Control Agent of Exotic Ludwigia spp. in the USA," published in October 2022 in the Florida Entomologist. (See https://tinyurl.com/8csactwb)
Meanwhile, “Bugbie” is being sold on the EGSA website for $25 each at https://ucdavisentgrad.square.site/.
One of EGSA's all-time best sellers is The Beetles, mimicking the Beatles' Abbey Road image. The inventory also includes bees, cicadas, nematodes, a whip scorpion and a praying mantis.
They all pale in comparison to the hot pink Barbie "Bugbie" T-shirt.
- Author: Kathy Keatley Garvey
Assistant professor Laura "Melissa" Guzman of the University of Southern California (USC) will discuss "Using Occupancy Models to Infer Trends of Bee Biodiversity in North America" at the April 29th seminar hosted by the UC Davis Department of Entomology and Nematology.
Her seminar begins at 4:10 p.m. in 122 Briggs Hall and also will be on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/9 5882849672
"Historical museum records provide potentially useful data for identifying drivers of temporal trends in species occupancy, however, because these records were not explicitly collected for this purpose, methodological developments are needed in order to enable robust inferences," Guzman writes in her abstract. "Occupancy-detection models, a relatively new and powerful suite of methods, are potentially useful here, because these models allow us to account for changes in collection effort through space and time. Applying such occupancy-detection models to historical museum records is not a straightforward process, as these models have strict data requirements that museum data usually do not meet."
"Here I will present a methodological road-map for using occupancy models to analyze historical museum records. I use simulated data-sets to identify how and when modeling decisions and patterns in data can bias inferences. I will focus primarily on the consequences of contrasting methodological approaches for dealing with species ranges and non-detections in both space and time. Finally, I will present an application of these methods to bees in North America and will present drivers of change for these species in the past 30 years."
Guzman says that the "overarching goal of my research is to develop statistical and computational methods to leverage large biodiversity datasets to learn about ecological processes. While we know that the distribution of some species is changing, it is actually very difficult to make reliable inferences as to which species are declining and by how much from the often messy and complex historical and spatial datasets that we have to work with — for example, historical museum records, where species occurrences are aggregated from studies with different sampling procedures."
"In order to address this gap," Guzman says, "my research focuses on determining if and how statistical models can be applied to historical records without yielding biased trends. In my research I also apply these statistical models to determine how the distribution of pollinators has changed through time, where museum records provide lots of information. I am also interested in determining which drivers (e.g. pesticide use, climate change, land use change, etc.) are causing the most decline of the most pollinator species."
"Another aspect of my research is to understand the processes that shape communities, for example, I have combined experiments and modelling to understand how the structure of body size in a community affects the stability of food webs. In more recent work, I used large-scale simulations and machine learning to identify the signal of metacommunity processes in ecological time series."
Guzman is a Gabilan assistant professor in USC's Department of Biological Sciences. She received two degrees from McGlll University: her bachelor's degree (2012) in biology and her master's degree (2013) in ecology and evolution. She obtained her Ph.D. at the University of British Columbia.
She recently co-authored a piece in the journal Ecology titled "A Data Set for Pollinator Diversity and their Interactions with Plants in the Pacific Northwest," published in November 2022.
The abstract:
"Pollinator populations have declined substantially in recent years. The resulting loss in pollination services has both ecological and economic consequences, including reductions in plant diversity and crop production and lower food security. Data sets that identify pollinators and their plant hosts are of the utmost importance for the light can shed on the main causes of pollinator declines. Here we present a data set that contains 67,954 individual pollinator records. The data were collected across the Pacific Northwest, primarily focused in British Columbia (Canada), with 182 individual sites over 11 years, between 2005 and 2017. This data set comprises multiple studies that aimed to collect information on pollinator abundance, diversity, and their interactions with plants. Overall, the data set includes 937 morphospecies (of which 482 were identified to the species level) of pollinators across 105 families, including data for bees, wasps, butterflies, moths, and flies. We also present information on the interactions of these species, with 473 species of plants. The data set is being released for noncommercial use only. Credits should be given to this paper (i.e., proper citation)."
Guzman won the American Society of Naturalists Young Investigator Award, 2022-2023, and the Canadian Society of Ecology and Evolution Early Career Award, 2022-2023.
For any technical Zoom issues, contact seminar coordinator Brian Johnson at brnjohnson@ucdavis.edu. The full list of spring seminars is here.