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Department of Biology Seminar

14th Annual Thomas Hunt Morgan Lecture: "Human Evolution and Adaptation in Africa"

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.

Invite

Date:
Location:
WT Young Library Auditorium

"Functional Screening Approaches to Identify Cellular Toxicity Mechanisms"

SelfieDr. Christopher Vulpe | Vulpe Lab

Bio
Chris Vulpe, MD, PhD. is a Professor at the University of Florida, Gainesville in the Center for Environmental
and Human Toxicology. Dr. Vulpe received his MD and PhD from the University of California, San Francisco.
Dr. Vulpe’s group uses systems level approaches in eukaryotes from yeast to people to identify the functional
components that respond to and modulate the consequences of environmental stressors. Most recently, his laboratory is utilizing genome wide and targeted CRISPR screens to understand the mechanisms of toxicity of environmental chemicals. Dr. Vulpe is an author or co-author on >175 papers in peer reviewed journals and books. His group uses functional, genomic, and genetic approaches to provide insight into mechanisms of toxicity in diverse model systems including human models such as human cell culture, organoids, and rodents, as well as ecologically relevant organisms such as Daphnia magna.
 

Graphics

Date:
Location:
Plant Science Building (Cameron Williams Auditorium) and Zoom: https://uky.zoom.us/j/88492095664

601 Seminar | "Long-distance Relationships in the Control of Gene Regulation During Development, Disease, and Evolution"

SelfieDr. Francois Spitz | Spitz Lab

Bio:
PhD from Université Paris 6 (France)
Group Leader at the European Molecular Biology Laboratory (2006-2015) (Heidelberg, Germany)
Head of Research Unit at the Institut Pasteur (2015-2019) (Paris, France)
Professor, The University of Chicago (2019-.)

Abstract:
The mechanisms that regulate the efficiency and specificity of interactions between distant genes and cis-regulatory elements such as enhancers play a central role in shaping the specific regulatory programs that control cell fate and identity. In particular, the (epi)genetic elements that organize the 3D folding of the genome in specific loops and domains have emerged as key determinants of this process. I will discuss our current views on how 3D genome architecture is organized, how it influences gene regulatory interactions and illustrate how alterations of the mechanisms and elements that organize genomes in 3D could contribute to genomic disorders and genome evolution.

Date:
-
Location:
THM 116

"Phased, Secondary siRNAs in Plant Reproduction and Other Pathways"

SelfieDr. Blake Meyers | Meyers Lab

BIO: 
Blake Meyers is a Member & Principal Investigator at the Donald Danforth Plant Science Center in St.
Louis, and he is a Professor in the Division of Plant Science and Technology at the University of
Missouri - Columbia. He formerly held the Edward F. and Elizabeth Goodman Rosenberg
professorship at the University of Delaware, where his research group was from 2002 to 2015. He
was elected as a Fellow of the American Association for the Advancement of Science (AAAS) in 2012,
and a Fellow of the American Society of Plant Biologists (ASPB) in 2017, the same year he was
awarded the Charles Albert Shull Award by the ASPB for outstanding investigations in the field of
plant biology. He was elected to the US National Academy of Sciences in 2022. After serving on the
editorial board since 2008, Blake became the Editor-in-Chief of The Plant Cell in January 2020. Work
in his lab addresses the biological functions, biogenesis, genomic impact, and evolution of small
RNAs in diverse plant species, using combination of genomic and molecular genetics approaches,
with a focus on phased, secondary siRNAs (“phasiRNAs”).

He received his undergraduate degree in biology from the University of Chicago in 1992, and
working with Prof. Richard Michelmore at UC Davis, was awarded M.S. and Ph.D. degrees in genetics in 1995 and 1998, respectively. After that, he did a postdoc with Prof. Michele Morgante at DuPont Crop Genetics, working on maize genomics for 2 years before returning to Prof. Michelmore’s group at UC Davis in 2000 to do a 2nd postdoc on Arabidopsis disease resistance. In 2002, Blake started his
own research group at the University of Delaware. He was the chair of the Department of Plant & Soil Sciences at the University of Delaware from 2009 to 2015.

Abstract:
In plants, 21 or 22-nt miRNAs or siRNAs typically negatively regulate target genes through mRNA cleavage or translational inhibition. Heterochromatic or Pol IV are 24-nt and function to maintain heterochromatin and silence transposons. Phased “secondary” siRNAs (phasiRNAs) are generated from mRNAs targeted by a typically 22-nt “trigger” miRNA, and are produced as either 21- or 24-mers via distinct pathways. Our prior work in maize and rice demonstrated the temporal and spatial distribution of two sets of “reproductive phasiRNAs”, which are extraordinarily enriched in the male germline of the grasses. These two sets are the 21-nt (pre-meiotic) and 24-nt (meiotic) siRNAs. Both classes are produced from long, non-coding RNAs, generated by hundreds to thousands of loci, depending on the species. These phased siRNAs show striking similarity to mammalian piRNAs in terms of their abundance, distribution, distinctive staging, and timing of accumulation, but they have independent evolutionary origins. The functions for these small RNAs in plants remain poorly characterized. I will describe our recent work investigating the functions of plant phasiRNAs and their roles in modulating traits of agronomic importance in plants, including male fertility, as well as novel applications of phasiRNAs such as those generated from transplastomic plants.

 

Date:
Location:
Plant Science Building-Cameron Williams Auditorium

"Cells and Molecules for Touch, Pain and Interoception"

Dr. Alexander Chesler | Chesler Lab

Chesler
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!

Date:
Location:
THM 116

"Leveraging Animal Behavioral Interactions to Learn About Cognition & Social Dynamics"

Selfie

 

 

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!

 

Date:
Location:
THM 116

"Overwintering in the Arctic: Animal Strategies for Surviving the Long, Cold, and Dark"

SelfieDr. 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!

Date:
Location:
THM 116

"Highlights from 57 Years of Studying the Ecology, Biogeography and Evolution of Seed Dormancy and Germination"

SelfieDr. 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 (1st ed.) 2014 (2nd ed.), Elsevier/Academic Press,” which contained a complication of data on the world biogeography of seed dormancy for ca. 3,000 (1st ed.) and 13, 600 (2nd 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!

Date:
Location:
THM 116

"Botanical research at Eastern Kentucky University: Fantastic ferns, conservation and beyond"

SelfieDr. 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.

Watch the seminar here!

Date:
Location:
THM 116

"The Evolution of Cell Types in the Cerebral Cortex"

SelfieDr. 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!

Date:
Location:
THM 116
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