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.

 Dr. Andy Sih | Sih Lab

Andy Sih’s laboratory works on the evolution of ecologically important behaviors (predator-prey, mating, and social behaviors) life history traits, and how these influence population and community ecological patterns,  Most projects examine freshwater organisms e.g., fish amphibian larvae, crayfish, insects and other freshwater invertebrates.  Current applied ecological interests include studying effects of pesticides on predator-prey interactions, and behavioral mechanisms underlying species invasions.

Dr. Vinod Kumar | Kumar Lab

Abstract:

Cycles in biological systems are all-pervasive in nature. Birds, like any other species, express daily rhythms in activity/rest, hormone secretion, and several other rhythmic characteristics. Most bird species also show long-term cycles in feeding behavior, body fattening (in migrants), reproduction, molt, or migration. Both daily and seasonal behaviors are under the strict control of the endogenous clock mechanisms, but the role of the environment remains critical for optimal performance and ultimately survival. Synchrony with the environment is achieved through the interaction of clock components with external cues (e.g. photoperiod), and internal coordination among different rhythmic physiological correlates is achieved through neural and endocrine signaling. Thus, we are interested to learn about how birds achieve precision in timing their daily and seasonal activities in sync with the periodic environment. Our research effort mainly centers around the “Avian Circadian and Seasonal Systems: Study from Behavior to Molecules”. The working hypothesis has been that specialized cells localized in different tissues express genes involved in the clock circuitry, and different cell populations control the food intake, body fattening, reproductive axis, molt, and migration, in a way that each event can be timed and spaced with each other to optimize an ecological adaptation. 

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. 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.

 

Dr. 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.

Dr. 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.

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!