Dr. Jesse Lasky | Lasky Lab

Bio:
Dr. Jesse Lasky attended Kenyon College and received his BA in Biology and a PhD in Ecology Evolution & Behavior at UT-Austin. Dr. Lasky was a postdoc at Columbia University and is now a faculty member at Penn State University, in addition to being the herbarium director.

Abstract:
Global patterns of population genetic variation through time offer a window into evolutionary processes that maintain diversity. Over time, lineages may expand or contract their distribution, causing turnover in population genetic composition. At individual loci, migration, drift, and selection (among other processes) may affect allele frequencies. Museum specimens of widely distributed species offer a unique window into the genetics of understudied populations and changes over time. Here, we sequenced genomes of 130 herbarium specimens and 91 new field collections of Arabidopsis thaliana and combined these with published genomes. We sought a broader view of genomic diversity across the species, and to test if population genomic composition is changing through time. We documented extensive and previously uncharacterized diversity in a range of populations in Africa, populations that are under threat from anthropogenic climate change. Through time, we did not find dramatic changes in genomic composition of populations. Instead, we found a pattern of genetic change every 100 years of the same magnitude seen when comparing Eurasian populations that are 185 km apart, potentially due to a combination of drift and changing selection. We found only mixed signals of polygenic adaptation at phenology and physiology QTL. We did find that genes conserved across eudicots show altered levels of directional allele frequency change, potentially due to variable purifying and background selection. Our study highlights how museum specimens can reveal new dimensions of population diversity and show how wild populations are evolving in recent history.

Watch the seminar here!

Dr. Caroline Geisler

Dr. Caroline Geisler

Dr. Caroline Geisler

Dr. Caroline Geisler

Dr. Caroline Geisler

Dr. Caroline Geisler

Dr. Shai Shaham | Shaham Lab

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. Shai Shaham | Shaham Lab

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. Shai Shaham | Shaham Lab

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!