All colloquia are in TBL 112 at 1:10pm on the dates below (except where noted).
September 8, 2017 – Norm Bell, Safety talk for all students working in labs. This is mandatory!!
September 15, 2017 – “Strategies for designing and delivering a scientific presentation” (by Matt Carter, Assistant Professor of Biology)
It takes time, effort and skill to design and deliver an engaging scientific talk that audiences understand and remember. In this one-hour presentation, we will discuss three aspects of designing an outstanding scientific talk: (1) organizing complex scientific information into a clear narrative; (2) using PowerPoint or Keynote software to visually communicate scientific concepts; and (3) improving verbal and nonverbal delivery during a presentation. This seminar is open to anyone and is especially applicable to senior thesis students.
September 22, 2017 – Adam Siepielski, University of Arkansas
“A cautionary tale of woe and intrigue in explaining species diversity”
Spectacular levels of species diversity exemplify most biological communities: plankton in freshwater and marine systems, beetles in a tree, plants in tropical forests or grasslands, and microbes in the human gut. What allows so many ecologically similar species to locally coexist? Progress into this vexing problem has primarily focused on identifying ecological differences among species that could promote coexistence. However, missing are critical tests determining whether or not ecological differences among species do indeed promote coexistence via their effects on population regulation. Likewise, the role of evolution in shaping the ability for species to coexist via its demographic effects is often missing. Yet, evolution is relentless. I’ll explore these ideas using a diverse assemblage of aquatic insect predators – damselflies, which are a close relative of dragonflies. The work will reveal some of the complexities and joys of studying species diversity from ecological and evolutionary perspectives. Given the importance of biodiversity, understanding how diversity is maintained remains and will remain an important and active area of study in the biological sciences.
September 29, 2017 – Zuzana Tothova (’01), Harvard
“Targeting cohesin mutations in leukemia”
Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) represent a group of diseases of the bone marrow hematopoietic stem cells, which are characterized by ineffective production of normal blood cells. While tremendous progress has been made in defining the genetic basis of MDS with the advent of next generation sequencing, little is known about the basic mechanisms by which newly identified drivers cause transformation. Patients with MDS have a poor overall prognosis given limited treatment options. Better understanding of the mechanisms by which these novel genetic drivers contribute to transformation will offer biological insight into myeloid diseases and inform the design of urgently needed new therapies. One of the protein complexes recurrently mutated in MDS and AML is the cohesin complex – a ring-like structure that wraps around the DNA and facilitates sister chromatid cohesion, DNA repair and chromatin organization. It is not understood how cohesin mutations lead to MDS or leukemia, or whether cells with these mutations have vulnerabilities that can be exploited therapeutically. I will discuss our data showing that the loss of STAG2, the most frequently mutated cohesin subunit, results in assembly of mutant cohesin complexes, disruption of critical DNA looping interactions and leads to transcriptional deregulation. Importantly, we reveal novel therapeutic vulnerabilities associated with these changes, which has informed design of new clinical trials.
October 6, 13, 20, 2017 – Thesis Talks (two of these three dates, depending on Mountain Day)
November 3, 2017 – Abhyudai Singh, University of Delaware
“Systems Biology in Single Cells: A Tale of Two Viruses”
In the noisy cellular environment, expression of genes has been shown to be stochastic across organisms ranging from prokaryotic to human cells. Stochastic expression manifests as cell-to-cell variability in the levels of RNAs/proteins, in spite of the fact that cells are genetically identical and are exposed to the same environment. Development of computationally tractable frameworks for modeling stochastic fluctuations in gene product levels is essential to understand how noise at the cellular level affects biological function and phenotype. I will introduce state-of-the-art computational tools for stochastic modeling, analysis and inferences of biomolecular circuits. Mathematical methods will be combined with experiments to study infection dynamics of two viral systems in single cells. First, I will show how stochastic expression of proteins results in intercellular lysis time and viral burst size variations in the bacterial virus, lambda phage. Next, I will describe our efforts in stochastic analysis of the Human Immunodeficiency Virus (HIV) genetic circuitry. Our results show that HIV encodes a noisy promoter and stochastic expression of key viral regulatory proteins can drive HIV into latency, a drug-resistant state of the virus.
February 9, 2018 – Byron Weckworth, Panthera, Director Snow Leopard Program CANCELLED
“Conservation in practice: from academics to grass roots”
The guiding principles in conservation dictate the importance of preserving biodiversity, maintaining ecological complexity and upholding evolutionary potential, as well as identifying that biodiversity has intrinsic value and that untimely extinctions should be prevented. Conservationists play many roles across various fields within the basic sciences and resource management. Conservation in practice requires successfully navigating the feedback loop between the new ideas and approaches provided by science and the field experience and research needs of resource managers, and then implementing the results into management and policy directives. Yet, in some cases, successful conservation dispenses with the formalities of this exchange in favor of local, grass roots interventions. Drawing from my own professional experiences in wildlife research and conservation, we will review results from studies of phylogeography, population genetics and ecology, predator-prey dynamics and social surveys, and examine the success and failure of their application to endangered species listing efforts for the Alexander Archipelago wolf, management of threatened woodland caribou in western Canada, and human-snow leopard conflict in Qinghai, China.
February 23, 2018 – Alumni Reunion with Emily Maclary ’10, Michael Abrams ’11, Gordon Smith ’13, Betsy Hart ’14 and Nitsan Goldstein ’15. The purpose of the reunion is to provide our students a window on the process of finding and gaining admission to graduate Ph.D or MD/Ph.D programs. The reunion has two parts. First, a panel discussion will be led by our visiting alumni who are now in Ph.D, MD/Ph.D or post-doctoral programs (in TBL 112 @ 2pm). Second, the panel will be followed by a poster session where students can talk individually with the panelists about their current research and about other topics related to moving forward towards a career in basic or medical research (in TBL 211 @ 3pm).
March 2, 2018 – Shaeri Mukherjee, UC San Francisco
“Lessons learned from intracellular bacteria—how to remodel and rewire the host cell”
The unfolded protein response (UPR) is an important cytoprotective pathway in the Endoplasmic Reticulum (ER) that is manipulated by several pathogens. Interestingly, while previous work demonstrated that most pathogens induce the UPR, we have discovered that the intracellular pathogenic bacteria, Legionella pneumophila (L.p.), both activates and inhibits it. The UPR is sensed by three ER membrane sensors: ATF6, PERK and IRE1. IRE1 has a lumenal domain and cytoplasmic endoribonuclease and kinase domains. We have shown that two L.p. effectors belonging to the glucosyltransferase family, Lgt1 and Lgt2 (Lgt1/2), block the IRE1-mediated XBP1u mRNA splicing. Glucosyltransferases are common among pathogen toxins but an effect on mRNA splicing has never been observed. Along with the UPR’s canonical role of sensing unfolded protein stress in the ER, it has also been implicated in the innate immune response. Therefore, this novel IRE1 role has energized efforts to understand previously uncharacterized relationships between pathogens and the UPR. Molecular dissection of this interaction will unravel novel mechanisms of bacterial pathogenesis and provide tools for probing and manipulating the UPR, which is implicated in numerous human diseases.
March 9, 2018 (BIMO Class of 1960 Scholar) – Tannishtha Reya, UC San Diego CANCELLED
“Stem Cell Signals in Cancer Heterogeneity and Therapy Resistance”
Our research focuses on the signals that control stem cell self-renewal and how these signals are hijacked in cancer. Using a series of genetic models, we have studied how classic developmental signaling pathways such as Wnt, Hedgehog and Notch play key roles in hematopoietic stem cell growth and regeneration and are dysregulated during leukemia development. In addition, using real-time imaging strategies we have found that hematopoietic stem cells have the capacity to undergo both symmetric and asymmetric division, and that shifts in the balance between these modes of division are subverted by oncogenes. Further, regulators of this process, including the cell fate determinant Musashi, are critical players in driving progression of solid and liquid cancers and could serve as targets for diagnostics and therapy. Ongoing work is focused on understanding the mechanisms that drive therapy resistance after drug delivery, as well as developing high resolution in vivo imaging approaches to map normal stem cell behavior and interactions within living animals, and to define how these change during cancer formation.
April 6, 2018 – Sonya Auer, Williams College
April 13, 2018 – Beronda Montgomery, Michigan State University
April 20, 2018 – Nicholas Betley, University of Pennsylvania
April 27, 2018 – David Seward (’98), University of Vermont
May 4, 2018 – Thesis Poster Presentations
Previous Years Schedule