- Author: Kathy Keatley Garvey
She will present her seminar at 4:10 p.m. in Room 122, Briggs Hall. Her seminar also will be virtual. The Zoom link: https://ucdavis.zoom.us/j/95882849672
Her abstract: “Neurons have two types of cellular projections, that are essential for how they function in circuits: they have a single axon and a highly branched network of dendrites. These dendrites are the cellular structures that allow neurons to receive input from the environment or from other neurons. While much is known about how axons respond to injury, almost nothing is known about how neurons respond to dendrite injury. We have found that after dendrite injury, peripheral nervous system neurons are able to mount a reliable, reproducible process of dendrite regeneration. In this talk, I present our recent work to determine how neurons detect injury to their dendrites, using the larvae and adult fruit fly Drosophila melanogaster as a model to study dendrite regeneration.”
A pre-seminar coffee takes place from 3:30 to 4:10 in Briggs 158.
Thompson-Peer, who joined UC Irvine in April 2019, received her bachelor's degree in biology from the University of Pennsylvania, and then followed with a two-year stint at the Johns Hopkins University with Alex Kolodkin. She earned her doctorate from Harvard University, working with Josh Kaplan, and was a postdoctoral fellow with Yuh-Nung and Lily Jan at UC San Francisco and the Howard Hughes Medical Institute. Her postdoctoral work drew financial support from the National Institute of Neurological Disorders and Stroke F32 and K99/R00 fellowships, as well as a UC Office of the President's Postdoctoral Fellowship.
The Thompson-Peer lab explores how neurons recover from injury in vivo, and how this process is similar to and different from normal development. (See her work on YouTube)
"At the most fundamental level, a neuron receives information along dendrites, and sends information down an axon to synaptic contacts," she writes on her website. "Dendrites can be injured by traumatic brain injury, stroke, and many forms of neurodegeneration, yet while the factors that control axon regeneration after injury have been extensively studied, we know almost nothing about dendrite regeneration. Our long-term research goal is to understand the cellular mechanisms of dendrite regeneration after injury."
"Our previous work found that the sensory neurons in the fruit fly Drosophila peripheral nervous system exhibit robust regeneration of dendrites after injury and used this system to explore central features of dendrite regeneration in developing animals, young adults, and aging adults. We have observed that after injury, neurons regrow dendrites that recreate some features of uninjured dendrites, but are unable to reconstruct an entire arbor that perfectly mimics an uninjured neuron. Moreover, there are mechanistic differences between the outgrowth of uninjured neurons versus the regeneration of dendrites after injury: dendrite regeneration is uniquely dependent on neuronal activity, ignores cues that constrain and pattern normal dendrite outgrowth, and confronts a mature tissue environment that is different from what a developing neuron would encounter. These challenges are significantly exacerbated when neurons in aging animals attempt to recover from injury."
Department seminar coordinator is urban landscape entomologist Emily Meineke, assistant professor. For technical issues regarding Zoom connections, she may be reached at ekmeineke@ucdavis.edu. (See complete list of spring seminars.)
- Author: Kathy Keatley Garvey
Hammer will speak at 4:10 p.m. in 122 Briggs Hall. The Zoom link:
https://ucdavis.zoom.us/j/99515291076.
Community ecologist Rachel Vannette, associate professor, UC Davis Department of Entomology and Nematology, is hosting the seminar.
"How do insects and microbes form symbioses, and why do these partnerships often break down?" Hammer asks in his abstract. "We are addressing these questions with the gut microbiomes of social corbiculate bees. Despite an ancient association with their bee hosts, these symbionts are surprising dynamic over developmental, ecological and macroevolutionary time scales. I will discuss our recent discoveries of symbiont loss in bees, and efforts to understand why and how these losses occur."
Hammer received his bachelor's degree in general biology from UC San Diego in 2009 and his doctorate in evolutionary biology in 2018 from the University of Colorado, Boulder. He served as a postdoctoral researcher at the University of Texas, Austin, from 2018 to 2021.
Hammer's research interests include microbiomes, symbiosis, microbial ecology and evolution, bees, biodiversity, insect-plant interactions and tropical biology.
"We are a new research group at UC Irvine studying the ecology and evolution of symbioses between hosts (especially bees) and microbes," he writes on his lab website. His mission:
- To boldly venture into uncharted waters of symbiosis and bee biology, asking—and doing our best to answer—new questions about how they tick.
- To create a culture where lab members follow their curiosity, have fun, and regularly enjoy homemade baked goods.
- To contribute to making the academic community better reflect the diversity of society, and be a more welcoming, supportive place for historically marginalized scientists.
- To help wild bees, and connect people outside academia to insect biodiversity.
Hammer's most recent publications include
- Hammer, T.J., Le, E., Martin, A.N., Moran, N.A. 2021. The gut microbiome of bumblebees. Insectes Sociaux 68, 287-301.
- Silva Cerqueira, A.E., Hammer, T.J., Moran, N.A., Cristiano Santana, W., Megumi Kasuya, M.C., Canêdo da Silva, C. 2021. Extinction of anciently associated gut bacterial symbionts in a clade of stingless bees. The ISME Journal 15, 2813-2816.
- Hammer, T.J., Le, E., Moran, N.A. 2021. Thermal niches of specialized gut symbionts: the case of social bees. Proceedings of the Royal Society B 288, 20201480.
- Hammer, T.J., De Clerck-Floate, R., Tooker, J.F., Price, P.W., Miller, D.G., Connor, E.F. 2021. Are bacterial symbionts associated with gall induction in insects? Arthropod-Plant Interactions 15, 1-12.
- Hammer, T.J., Dickerson, J.C., McMillan, W.O., Fierer, N. 2020. Heliconius butterflies host characteristic and phylogenetically structured adult-stage microbiomes. Applied and Environmental Microbiology 86, e02007-20.
Nematologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology, is coordinating the spring seminars. For Zoom technical issues, contact him at ssiddique@ucdavis.edu.