The Research Talks provide an opportunity for students and postdocs in the Biology department to present their work to the entire department. We encourage everyone to attend and support these presentations!
The Research Talks provide an opportunity for students and postdocs in the Biology department to present their work to the entire department. We encourage everyone to attend and support these presentations!
The Research Talks provide an opportunity for students and postdocs in the Biology department to present their work to the entire department. We encourage everyone to attend and support these presentations!
The Research Talks provide an opportunity for students and postdocs in the Biology department to present their work to the entire department. We encourage everyone to attend and support these presentations!
The Research Talks provide an opportunity for students and postdocs in the Biology department to present their work to the entire department. We encourage everyone to attend and support these presentations!
The Research Talks provide an opportunity for students and postdocs in the Biology department to present their work to the entire department. We encourage everyone to attend and support these presentations!
LEXINGTON, Ky. (Jan. 27, 2025) — Research conducted by an international team led by biologists at the University of Kentucky has found that the ability to regenerate complex tissue may be more widespread in mammals than previously thought — an important step toward figuring out why many most mammals, and humans in particular, have poor regenerative ability.
Bio:
Glial cells are major components of nervous systems, and are in a position to influence nearly every
step of neural information transfer and processing. To understand if and how glia control nervous system
functions, the Shaham lab developed the nematode C. elegans as a unique setting to probe glia-neuron
interactions; demonstrating that glia in this animal can be interrogated without perturbing neuronal viabilityan
important experimental advantage. Using molecular, cell-biological, and physiological tools, developed in part by the Shaham lab group, the lab identified multiple mechanisms by which glia influence nervous system development and function. The Shaham lab showed that the four CEPsh glia of C. elegans are astrocyte-like glia that play central roles in modulating locomotory behavior. The Shaham lab also investigated glia that ensheath sensory-neuron receptive endings, and identified novel signaling interactions with these neurons that control an animal’s response to environmental stimuli. Dr. Shaham will describe recent published and unpublished findings that support the notion that glia play active and critical roles in defining behaviorally consequential activity set points in the nervous system. The lab hypothesizes that many of the rules we describe are conserved across animals, and Dr. Shaham will discuss evidence that
supports this idea.
Shai Shaham received his A.B. degree in biochemistry from Columbia University in 1989. In 1995, he graduated from the Massachusetts Institute of Technology with a Ph.D. in biology. After postdoctoral studies at the University of California, San Francisco, Shaham joined Rockefeller as assistant professor in 2001. He was named associate professor in 2007 and professor in 2012. Shaham was named a Sidney Kimmel Foundation for Cancer Research Scholar and a Rita Allen Foundation Scholar. He has received an Irma T. Hirschl/Monique Weill-Caulier Trust Research Award, a Masin Young Investigator Award from the Breast Cancer Alliance, a Klingenstein Fellowship, The Rockefeller University Distinguished Teaching Award, a Blavatnik Award, and a NINDS Outstanding Investigator Award.
Abstract:
Glial cells are major components of nervous systems and are in a position to influence nearly every step of neural information transfer and processing. To understand if and how glia control nervous system functions, we developed the nematode C. elegans as a unique setting to probe glia-neuron interactions; demonstrating that glia in this animal can be interrogated without perturbing neuronal viability- an important experimental advantage. Using molecular, cell-biological, and physiological tools, developed in part by our group, we identified multiple mechanisms by which glia influence nervous-system development and function. We showed that the four CEPsh glia of C. elegans are astrocyte-like glia that play central roles in modulating locomotory behavior. We also investigated glia that ensheath sensory-neuron receptive endings, and identified novel signaling interactions with these neurons that control an animal’s response to environmental stimuli. Our studies support the notion that glia play active and critical roles in defining behaviorally consequential activity set points in the nervous system. We hypothesize that many of the rules we describe are conserved across animals, and will provide evidence that supports this idea.
Watch the seminar here!
Dr. Boris Igic | Igic LabBrief Bio:
Professor of Biology at the University of Illinois at Chicago and Research Associate, Field Museum of Natural History.
Abstract:
The vast majority of angiosperms simultaneously produce pollen and ovules. Despite the obvious potential for self-fertilization, most instead predominantly or exclusively cross-fertilize. The most important contrivance used by flowering plants to ensure cross-fertilization is self-incompatibility (SI). SI is a suite of mechanisms that prevents zygote formation by recognizing and rejecting a plant’s own pollen. SI strongly scales effective population sizes and shapes both spatial and temporal distribution of genetic variation. This, in turn, determines the rate of adaptation with far-reaching consequences for the evolution of other traits.
Nevertheless, SI faces high mutation rate and selection favoring transition from SI to self-compatibility (SC). One-half of angiosperm species are self-fertile, and the transition from SI to SC is one of the best trod evolutionary pathways in flowering plant evolution. Here, I present our recently developed candidate-based, phylotranscriptomic approach for rapid discovery of genes that underly such traits (Ramanauskas and Igic 2021, 2023, Ramanauskas et al. 2025). Using both our original data and a literature review, I discuss the significance of the massive convergence and deep homology of SI, an unusual "meta key innovation" across flowering plants.
Genetic mechanisms causing SI are complex and varied, but each minimally comprises of a self-recognition reaction between pollen- ("male") and pistil-expressed ("female") genes, leading to a regulatory cascade and death of self-pollen. Remarkably similar--yet clearly distinct and convergent--SI systems have independently evolved many times. And yet, one SI system (RNase-based SI) is extraordinarily widespread and homologous. It has been continually present since the common ancestor of eudicots 120+ My ago, and gave rise to 200,000+ species, nearly 75% of all flowering plants
References
Ramanauskas, K., F.J. Jimenez-Lopez, M. Sanchez-Cabrera, M. Escudero, P.L. Ortiz, M. Arista, and B.Igic. 2025. Rapid Detection of RNase-based Self-incompatibility in Lysimachia monelli (Primulaceae). American Journal of Botany 112:e16449 16pp. https://bsapubs.onlinelibrary.wiley.com/doi/full/10.1002/ajb2.16449
Ramanauskas, K. and B. Igic. 2023. kakapo: Easy extraction and annotation of genes from raw RNA-seq reads. PeerJ e16456 13pp. https://peerj.com/articles/16456/
Ramanauskas, K. and B. Igic. 2021. RNase-based self-incompatibility in cacti. New Phytologist 231:2039-2049. https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/nph.17541
