Dr. Benjamin Garcia | Garcia Lab

Bio: 
Benjamin A. Garcia obtained his BS in Chemistry at UC Davis in 2000, where he worked as an undergraduate researcher in Prof. Carlito Lebrilla’s laboratory. He received his PhD in Chemistry in 2005 at the University of Virginia under Prof. Donald Hunt and then was an NIH NRSA Postdoctoral Fellow at the University of Illinois under Prof. Neil Kelleher from 2005-2008. From there Ben was appointed as an Assistant Professor in the Molecular Biology Department at Princeton University from 2008-2012, until his recruitment as the Presidential Associate Professor of Biochemistry and Biophysics at the University of Pennsylvania Perelman School of Medicine in 2012, promoted to full Professor in 2016, and named the John McCrea Dickson M.D. Presidential Professor in 2017. Ben moved in the summer of 2021 to the Washington University School of Medicine in St. Louis to become the Raymond H. Wittcoff Distinguished Professor and Head of the Department of Biochemistry and Molecular Biophysics. The Garcia lab has been developing and applying novel proteomic approaches and bioinformatics for interrogating protein modifications, especially those involved in epigenetic mechanisms such as histones during human disease, publishing over 400 publications. He is presently an Associate Editor of the Analytical Chemistry, and Mass Spectrometry Reviews journals; and serves on the editorial boards for the Molecular Omics, the Journal of Proteome Research and the Molecular and Cellular Proteomics journals. He also serves on the Board of Directors for the U.S. Human Proteome Organization (HUPO), the HUPO Governing Council/Executive Committee and the Executive Committee of the American Chemical Society (ACS) Analytical Chemistry Division. Ben has been recognized with many honors and awards for his mass spectrometry research including the American Society for Mass Spectrometry (ASMS) Research Award, a National Science Foundation CAREER award, an NIH Director’s New Innovator Award, the Presidential Early Career Award for Scientists and Engineers (PECASE), an Alfred P. Sloan Fellowship, the PITTCON Achievement Award, the Ken Standing Award, the ACS Arthur F. Findeis Award, The Protein Society Young Investigator Award, the ASMS Biemann Medal, the HUPO Discovery in Proteomic Sciences Award, the Eastern Analytical Symposium (EAS) Outstanding Achievement in Mass Spectrometry Award and was named a Fellow of the Royal Society of Chemistry.

Abstract:
Histones are small proteins that package DNA into chromosomes, and a large number of studies have showed that several post-translational modification (PTM) sites on the histones are associated with both gene activation and silencing.  Along with DNA and small non-coding RNA, histone PTMs make up epigenetic mechanisms that control gene expression patterns outside of DNA sequence mutations. Dysregulation of these chromatin networks underlie several human diseases such as cancer. Here I will give an update on technology advancements that have allowed for high-throughput quantitative mass spectrometry analyses of histone PTMs and chromatin structure, and how we are applying these methods to understand epigenetic reprogramming found in malignant peripheral nerve sheath tumors (MPNSTs). MPNST is an aggressive sarcoma with recurrent loss of function alterations in polycomb-repressive complex 2 (PRC2), a histone-modifying complex involved in transcriptional silencing.

Dr. Cassandra Extavour | Extavour Lab

Bio: 
Cassandra Extavour is a native of Toronto, where she attended the University of Toronto Schools and went on to obtain an Honors BSc at the University of Toronto with a specialist in Molecular Genetics and Molecular Biology, a Major in Mathematics and a Minor in Spanish. She obtained her PhD with Antonio Garcia Bellido at the Severo Ochoa Center for Molecular Biology at the Autonomous University of Madrid. She performed postdoctoral work first with Michalis Averof at the Institute for Molecular Biology and Biotechnology in Crete, Greece, and subsequently with Michael Akam at the University of Cambridge. At Cambridge she received a BBSRC Research Grant and became a Research Associate in the Department of Zoology. In 2007 she established her independent laboratory as an Assistant Professor in the Department of Organismic and Evolutionary Biology at Harvard University, where she was promoted to Associate Professor in 2011 and to Full Professor in 2014. In 2021 she became a Howard Hughes Medical Institute Investigator, and was named the Timken Professor of Organismic and Evolutionary Biology and of Molecular and Cellular Biology at Harvard. Click here to read more.

Abstract:
Reproduction is a crucial fitness parameter, essential for species survival and evolution. Despite its importance, there is massive variation in reproductive capacity across animals, even between very closely related species. Moreover, reproductive capacity can be modified by environmental and ecological factors. Our aim is to understand how genetic variation interacts with ecological variation to regulate distinct and reproductive capacities between species, to determine whether and how ecological variation contributes to the evolution of adaptive variation in reproductive capacity. Our approach takes advantage of the fact that in sexually reproducing animals, the number of offspring that an individual can produce is often predicted by the anatomy of the ovary or testis, the sites of gamete production. In female insects, ovaries are subdivided into egg-producing units called ovarioles, which are generated in species-specific numbers during development. Ovariole number, and correspondingly reproductive capacity, can vary by more than four orders of magnitude across insects. I will discuss our findings on the mechanisms of genetic and environmental control of ovariole number in closely and distantly related insect species, and their implications for the broader questions of the genetic and developmental basis of fitness-relevant evolutionary change.

Click here for more information about Dr. Sarah Tishkoff.

Abstract:

Africa is thought to be the ancestral homeland of all modern human populations.  It is also a region of tremendous cultural, linguistic, climatic, and genetic diversity.   Despite the important role that African populations have played in human history, they remain one of the most underrepresented groups in human genomics studies. A comprehensive knowledge of patterns of variation in African genomes is critical for a deeper understanding of human genomic diversity, the identification of functionally important genetic variation, the genetic basis of adaptation to diverse environments and diets, and for reconstructing modern human origins. African populations practice diverse subsistence patterns (hunter-gatherers, pastoralists, agriculturalists, and agro-pastoralists) and live in diverse environments with differing pathogen exposure (tropical forest, savannah, coastal, desert, low altitude, and high altitude) and, therefore, are likely to have experienced local adaptation. In this talk I will discuss results of analyses of genome-scale genetic variation in geographically, linguistically, and ethnically diverse African populations in order to reconstruct human evolutionary history in Africa, African and African American ancestry, as well as the genetic basis of adaption to diverse environments.

Dr. Alexander Chesler | Chesler Lab

Bio: 
Dr. Chesler received his degrees from Bard College (B.A., 1995) and Columbia University (Ph.D., 2005). His graduate study, in the laboratory of Dr. Stuart Firestein, was focused on the function and development of olfactory sensory neurons. He did his postdoctoral training in the laboratory of Dr. David Julius at the University of California, San Francisco, where he combined physiological, anatomical, and behavioral approaches to study the pharmacology of somatosensory neurons. He joined the NIH intramural pain program (NCCIH) in 2013 where his laboratory now employs multidisciplinary approaches to study how sensory stimuli (such temperature, touch, and environmental irritants) are detected and encoded by the somatosensory system.

Watch the seminar here!

Dr. Elizabeth Hobson | Hobson Lab

Bio: 
Dr. Hobson received her PhD from New Mexico State University and was awarded two independent postdoctoral fellowships, the first at NIMBioS (the National Institute for Mathematical and Biological Synthesis) and the second at the Santa Fe Institute. She started her lab at the University of Cincinnati in Fall 2019 and is currently an Assistant Professor.

Abstract:
In many social species individuals create their social worlds through interaction decisions and are then subject to and constrained by these social constructs, which can affect an individual’s future actions. Understanding how much individuals “know” about their social worlds is critical in understanding these potential feedbacks. However, it is difficult to determine how much information individuals have about the social structures in which they live. In this talk, I summarize several ways my group is addressing these questions by combining empirical experiments with computational approaches to provide insight into cognition through social decisions. I highlight new work on parakeet aggression and dominance hierarchies to illustrate this approach. I show evidence that parakeet rank is unlikely due to individual characteristics and that group-level social dominance patterns can be plastic and can respond to group membership changes. Finally, I show how parallel or related experiments can allow for comparative analyses across species. These approaches, and a taxonomically broad perspective, provide new opportunities to investigate the effect of social information on individual behavior within conflict, and has the potential to provide rigorous evidence for the evolutionary patterns underlying social cognition.

Watch the seminar here!

Dr. Brian Barnes

Bio:
Dr. Barnes is currently a Professor of Zoophysiology with the Institute of Arctic Biology at the University of Alaska in Fairbanks. He's also the Director of Alaska INBRE, an NIH capacity building program in biomedical research and also the Science co-Director at Toolik Field Station. He participated in summer workshops involving biological rhythms at Hopkins Marine Station. He has a  PhD in Zoology from the University of Washington where Jim Kenagy was his advisor. Dr. Barnes received his Post-doc in Psychology and Zoology with Irv Zucker and Paul Licht as advisors. He began as Assistant Professor at the University of Alaska in 1986.

Abstract:
In Alaska, winters begin early, last seemingly forever, are very cold, snowy and dark, as well as extremely beautiful, quiet, and serene. This talk will review the physiological and behavioral strategies available to animals for surviving and coping with arctic winters, including cryobiology in insects, freeze tolerance in frogs, and hibernation in ground squirrels and bears. Using data logging and advanced telemetry, the locations, behavior, sleep, circadian rhythms, cardiovascular patterns, and thermoregulation of animals were recorded as they overwinter under natural conditions.

Cucujus beetle larvae may not freeze at temperatures below -80C, wood frogs freeze almost solid and survive; arctic ground squirrels lose track of time, become torpid while colder than ice but warm to sleep, even as black bears continuously doze, only occasionally snore, and their hearts beat in a syncopated rhythm. Little is known about the genetic and molecular basis of hibernation, but discovering its mechanisms could lead to novel clinical therapies and escape strategies in humans.

Watch the seminar here!

Dr. Carol Baskin 

Abstract:
What controls the timing of seed germination in nature? This question is of much interest because the timing of seed dormancy-break and germination are an important part of the adaptation of a species to its habitat. Thus, we want to know what environmental conditions are required for seed dormancy-break and germination in various kinds of habitats from the tropics to the arctic, i.e. germination ecology.

My first germination experiments were conducted in 1966 when I was a graduate student at Vanderbilt University; I am still expanding my knowledge about seeds of wild plants. My original work/interests have expanded from germination ecology to the world biogeography of nondormancy and of the five classes/kinds of dormancy and to the evolutionary relationships of nondormancy and the classes of dormancy.

I have studied ca. 400 species from Kentucky/Tennessee, as well as species from Hawaii, Tiawan and Sweden. With collaborators, I have been involved in seed germination studies in Argentina, Australia, Brazil, China, India, Iran and Japan. The world biogeography of seed dormancy was part of a book entitled “Seeds: ecology, biogeography, and evolution of dormancy and germination, C.C. Baskin and J.M. Baskin, 1998 (1^st ed.) 2014 (2^nd ed.), Elsevier/Academic Press,” which contained a complication of data on the world biogeography of seed dormancy for ca. 3,000 (1^st ed.) and 13, 600 (2^nd ed.) species. This data set provides an overview of seed dormancy of trees, shrubs and herbs in all the major vegetation zones on earth, and it has now been used by various collaborators to help investigate other aspects of seed biology, including the evolution of seed dormancy (i.e. dormancy transition states).  

I am a plant ecologist, and as such I seek information about the fossils and palaeohistory of seeds, embryo morphology, dormancy-breaking and germination requirements of seeds of species in all the major vegetation zones on earth and evolutionary relationships of nondormancy and the five classes of dormancy. Recently, I have been exploring how palaeohistory, biogeography and phylogeny have influenced seed dormancy-breaking and germination requirements in highly species-rich families such as the Asteraceae (ca. 30,000 species, sunflower family), Myrtaceae (ca. 6,000, Eucalyptus family) and Rubiaceae (ca. 13, 460 species, coffee family).

Watch the seminar here!

Dr. Sally Chambers

Abstract:

Kentucky is a botanically diverse state home to over 2,000 native plants and more than 400 taxa that are of conservation concern. Kentucky’s native plants are phylogenetically diverse, and a subset of taxa reflect Kentucky’s geologic history as tropical relicts. This is especially true for the ferns in Kentucky, as many species occupy sandstone rock shelters which buffer extreme climatic conditions much like cave ecosystems. These microclimatic pockets create unique distribution patterns for the ferns that occupy this niche space, and even further partition the fern life cycle such that some crevices host only gametophytes while others host both gametophyte and sporophyte generations. This talk will focus on decades of work conducted in these unique rock shelter environments and the spatial differentiation of fern generations (gametophyte/sporophyte) in Kentucky, the Appalachians and beyond. Ecological research focusing on topics such as local adaptation, physiological tolerance limits, and population differentiation will be discussed. The remainder of the talk will highlight the botanical resources housed at Eastern Kentucky University and the utility of these natural history collections to scientists worldwide.



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Dr. Maria Antonietta Tosches | Tosches Lab

Abstract:

The cerebral cortex is arguably the brain area that underwent the most profound transformations in vertebrate brain evolution. The expansion of the cerebral cortex in mammals was accompanied by an explosion of neuronal diversity. To discover general principles underlying the evolution of neuron types and circuits, we study the simple cerebral cortices of non-mammalian vertebrates. Our recent work has focused on the Spanish newt Pleurodeles waltl, a species with a key phylogenetic position in the vertebrate tree. We are investigating the neuroanatomy, cell type composition, and function of the Pleurodeles brain using a combination of modern neuroscience tools.

Our work on amphibians and reptiles indicates that the cerebral cortex of ancestral tetrapods was layered, with two main classes of neurons with distinct laminar positions, molecular identities, and long-range projections. In salamanders, these two layers are generated sequentially from multipotent progenitors in an outside-in sequence. We propose that in mammals new types of pyramidal neurons evolved from these two ancestral classes by diversification, through the emergence of novel gene regulatory interactions during neuronal differentiation.

Watch the seminar here!