Grad News Forum

In 2012, the Centers for Disease Control and Prevention (CDC) reported that over one-third of US adults are obese, and that the medical costs associated with obesity in 2008 were estimated at $14.7 billion, with rates and costs expected to increase. The molecular and epidemiological cause of this emerging epidemic in the US and world populations was the basis of the 6^th Annual Integrative Biology Symposium, held on April 24^th. This year’s topic was “Obesity and Human Health.”

The Integrative Biology Symposium was started in 2008, with the goal to “host an interdisciplinary symposium that would help to bring the broader Dartmouth community interested in biomedical research together,” according to Professor Jason Moore. “Another important goal was to provide a forum for students to showcase their work and to interact with national and international leaders.” Past symposia topics have included “Human Microbiome in Health and Disease” (2012), “RNA and Disease: Beyond the Central Dogma” (2011), “Clinical and Translational Research” (2010), “Emerging Technology” (2009), and more generally, the inaugural event covered biostatistics, genomics, bioinformatics, and proteomics (2008).

Of the 200 registrants for this year’s symposium, 98 were students, 14 of whom presented posters at an evening poster session on April 23^rd. Winners of the poster session were graduate students Jeremy Huckins (Psychological and Brain Sciences), Corina Lesseur (Program in Experimental and Molecular Medicine), and Jie Tan (Molecular and Cellular Biology, first year), as well as undergraduate students, Rachael Bornstein (Dartmouth Class of 2014) and Brad Stubenhaus (from Keene State College in Keene, New Hampshire).

Speakers at the symposium consisted of three from the Geisel School of Medicine at Dartmouth: Diane Gilbert-Diamond, PhD, Richard Rothstein, MD, and Benjamin Moyer, PhD, as well as six outside speakers: Pamela Goodwin, MD (Mount Sinai Hospital, Toronto, Canada), Ruth Loos, PhD (Mount Sinai Hospital, New York, New York), Cecilia Lindgren, PhD (Broad Institute of MIT and Harvard, Cambridge, Massachusetts, and Oxford University, United Kingdom), David Allison, PhD (University of Alabama, Birmingham, Alabama), Lee Kaplan, MD, PhD (Massachusetts General Hospital, Boston, Massachusetts), and the keynote speaker, Joel Hirschhorn, MD, PhD (Broad Institute of MIT and Harvard, Cambridge, Massachusetts).

These nine speakers discussed topics encompassing the genetics of obesity, Western diets as agents of obesity, innovative interventions for weight and diabetes management, the application of genome-wide association studies (GWAS) to identify potential biomarkers for elevated obesity risk, and many others.

The Integrative Biology Symposium is sponsored by a number of Dartmouth-affiliated groups and programs, including the Dartmouth-Hitchcock Norris Cotton Cancer Center, the Institute for Quantitative Biomedical Sciences (iQBS), the Dartmouth Toxic Metals Superfund Research Program (SRP), the Dartmouth Lung Biology Center, the Children’s Environmental Health and Disease Prevention Center at Dartmouth, and the New Hampshire Network of Biomedical Research Excellence (NH-INBRE). In order to choose the symposium themes, topics are discussed and voted on by the Integrative Biology Committee, which meets monthly to plan and organize the yearly symposium. The theme for 2014 will be “Global Health.” According to Professor Moore, the group tries to pick themes which will broadly appeal to researchers across campus.

It appears that so far, the committee has been successful. Biochemistry graduate student Kelli Hvorecny stated, “I think the Integrative Biology Symposium is a great forum bringing the disparate research disciplines at Dartmouth together for discussion on a topic that touches all of their research. The exposure to techniques and fields of study that I do not encounter on a daily basis triggers outside-of-the-box ideas for my own research, often to my benefit.” When asked to provide a potential topic for a future symposium, Hvorecny suggests, “From molecules to medicine: Integrating the sciences spanning biochemistry to patient care.”

by Jeanine Amacher

photos by Carolee Crossmon

Congratulations to graduate student Marianna Kleyman, in the Department of Biochemistry, who was one of four winners of the Graduate Poster Session held recently in Alumni Hall! (Below is a summary of Kleyman’s poster.)

Poster Title: STAG2 Regulates Kinetochore-Microtubule Attachments in Human Cells

Chromosomes must be faithfully segregated during cell division to allow for normal growth and development of organisms. Errors in chromosome segregation cause birth defects and are common in many solid cancers yielding a heterogeneous population of cells. This increases the potential to resist drug treatment and metastasize, and generally leads to a poor cancer outcome for patients.

Cancer cells frequently missegregate whole chromosomes at high rates in a phenomenon called chromosomal instability, or CIN. CIN is caused by mal-attachments between chromosomes and the microtubule fibers responsible for movement of chromosomes during segregation.

The data demonstrate that loss of the chromosome-associated protein STAG2—important for chromosome cohesion—increases the frequency of mal-attachments of chromosomes to the microtubule fibers. The loss of STAG2 occurs in about 10-20% of cancers and results in the improper assembly of chromosomes. These data indicate that STAG2 plays an important role in ensuring faithful chromosome segregation in human cells.

poster summary by Marianna Kleyman

The Graduate Forum would like to congratulate Morgan Thompson on her recent publication in the prestigious scientific journal, Nature Structural and Molecular Biology, Volume 20, Issue 1. Thompson, who defended her dissertation this fall in biochemistry, collaborated on the article with Ernest Heimsath, Timothy Gauvin, and Professor Henry Higgs, all of the Department of Biochemistry, and Dean Jon Kull of both the Department of Biochemistry and the Department of Chemistry.

At Dartmouth, Thompson conducted research on proteins related to cell structure. She used a technique called X-ray crystallography to generate images of protein structures that are too small to see with even the most powerful microscope. Specifically, Thompson was interested in interactions between actin and formins, two proteins involved in facilitating cell movement. Actin molecules combine to form rigid filaments that give shape to cells, and formin molecules interact with actin to control actin filament growth.

In their recent article, Thompson and her collaborators investigated how formins promote actin filament elongation. Their work represents only the second example of a formin bound to actin visualized through crystallography, and the structure they modeled was probably closer to the way the proteins interact in nature than what has previously been observed. The process of crystallizing proteins to create structural images can cause them to act in ways that they would not naturally, explains Thompson, so it can be complicated to get images of physiological interactions. Research on the interaction of these proteins is significant because it increases our understanding of how cells change shape to move throughout the body, which is important for understanding various diseases, such as cancer.

One of Thompson’s main interests while at Dartmouth was in teaching, both undergraduates and younger students. She was a teaching assistant for four terms, for which she won the Graduate Teaching Award. Thompson also taught science to sixth graders in Enfield, New Hampshire, as part of a National Science Foundation Graduate Science, Technology, Engineering, and Mathematics in K-12 Education (GK-12) fellowship. In addition, Thompson led labs in several local fourth grade classrooms on the importance of hand washing, after her mother, a local fourth grade teacher, asked for her help in explaining germs to her students.

Thompson found spending time in the classroom especially rewarding—she recalls the thank you notes that she received from students after she had visited their classes. “One student even wrote me that it was the best day of his life!” she recalls. While she found her work in the lab very interesting, it was this time working with students and witnessing their developing interest in science that Thompson found particularly meaningful. She also feels that it is extremely important for Dartmouth, an institution with such a variety of resources, to contribute to the surrounding community.

As a result of her experiences, Thompson decided to pursue a career in teaching. She now works as a high school teacher at the Pingry School in New Jersey, where she teaches biology to students in ninth and tenth grade and a course in molecular biology methods to eleventh and twelfth graders. She enjoys her job, and, in particular, is excited that she can teach complex molecular methods to her students. Thompson notes that the methods she is teaching her juniors and seniors are “the same ones I used in my lab at Dartmouth.”

Thompson feels that her experiences as a graduate student at Dartmouth prepared her well for her new position in that she was able to develop her teaching skills as well as work on her research. She is grateful to the Dartmouth Center for the Advancement of Learning (DCAL) for the teaching support that they provided, as well as to her advisor, Dean Kull, who always encouraged her in all of her teaching and outreach endeavors. Having her dissertation work published in Nature is a satisfying culmination to her graduate career, and Thompson is eager to continue working with students to encourage others to be excited about science.

by Elizabeth Molina-Markham

On Thursday, February 28^th, the academic chair of the Graduate Student Council (GSC), Rich Lopez, hosted Nerd Nite, an event that provides an opportunity for graduate students to present their work to a general audience. The event was held at One Wheelock in Collis, and there were six presenters, a record for this year’s Nerd Nite events!

Rahme explaining his work on stem cells and their relationship to cancer to a very interested audience.

The presenters were:

-Kirsten Dalrymple (Department of Psychological and Brain Sciences)
-Rebecca Shapiro (Department of Computer Science)
-Kelli Hvorecny‎ (Department of Biochemistry)
-Everett Sullivan (Mathematics Department)
-Justin Foy (Department of Chemistry)
-Gilbert Rahme (Department of Genetics)

This Nerd Nite was divided into two sessions fueled with snacks, beer, and non-alcoholic beverages. Every presenter had ten minutes to present their work followed by a three-minute question and answer session.

The topics were extremely broad. Hvorecny explained a technique called X-ray crystallography used to visualize molecules like proteins and DNA. Dalrymple talked about her research on prosopometamorphopsia, a disorder of face perception in which faces appear grotesquely distorted to the perceiver. Other topics included wireless communication security, presented by Shapiro, and the study of mathematical knots and their complexities, discussed by Sullivan. Foy presented on proteins contained within each cell that function as motors. Rahme talked about stem cells that are the source of all functional cells in our bodies. He explained the relationship between stem cells and cancer development and maintenance.

Dalrymple presenting her work on prosopometamorphopsia.

All six presenters did a great job and got people very interested in their work. The audience continued to ask questions even after the event ended.

When asked about the frequency of Nerd Nite, Lopez said, “I am trying to make this event happen twice every semester. So far it has been a success, and I have had a good number of speakers.”

Follow the Dartmouth GSC on Facebook and check out the events calendar on the new GSC website to know when the GSC is hosting other similar events!

by Gilbert Rahme

photographs by Lisa Jackson

Graduate Studies wants to congratulate Ernest Heimsath on his new position at the National Institutes of Health (NIH). Ernest recently defended his dissertation in biochemistry in December, under the guidance of Professor Henry Higgs. He will be moving down to Bethesda, Maryland, in March to work as a postdoctoral researcher with Dr. Bechara Kachar in the National Institute on Deafness and other Communication Disorders (NIDCD), focusing on the functioning of auditory cells.

Ernest grew up in both Texas and Virginia and received his undergraduate degree from the University of Texas at San Antonio (UTSA), where he was supported by the NIGMS-funded Minority Biomedical Research Support (MBRS) program. While a junior at UTSA, he participated in the Summer Undergraduate Research Fellowship (SURF) program—now the Academic Summer Undergraduate Research Experience (ASURE) program—at Dartmouth. He enjoyed working in the Department of Biological Sciences that summer and appreciated the friendly, open-door policy of Dartmouth faculty. Ernest notes that he chose Dartmouth for graduate school partly as a result of this positive experience, as well as out of a desire to get to know a new area of the country.

While at Dartmouth, Ernest’s research has focused on polymerization of the protein, actin, which is the basis for many cellular structures. In particular, actin helps form filopodia, which are protrusions some cells use to sense their environment and help them migrate throughout the body. In a recent article published in the Journal of Biological Chemistry, Volume 287, Issue 5, Ernest examined a particular type of formin, which are proteins that regulate actin polymerization. He discovered that one formin in particular, called FMNL3, has unique effects on actin dynamics, which help to explain its role in assembling filopodia.

Ernest met Dr. Kachar in 2011 at the American Society for Cell Biology annual meeting, after being inspired by his work on sensory neurons in the inner ear, which was recently featured in Cell Picture Show. Ernest’s work at the NIDCD will relate to his previous research in that these neurons contain structures called stereocilia, which share much of the same actin-based architecture as filopodia, although they can be orders of magnitude larger and also more stable. Once formed during development, stereocilia last throughout your entire life and do not regenerate. As stereocilia are directly responsible for hearing, and dysfunctions in many of the components within them are attributed to hearing disorders, Ernest is excited about the clinical relevancy of the work he will be doing.

Ernest observes that his experience in Professor Higgs’ lab has prepared him well for this next career move. He says that he will miss the sense of community in the lab, as well as the unique Dartmouth environment. Dartmouth professors, explains Ernest, are “approachable,” and “faculty really care about developing grad students.” They are “down-to-earth” and open to being corrected, which is conducive to productive learning and research. Overall, Ernest is very satisfied with his graduate experience and looking forward to getting to know another new area of the country as a postdoc.

We wish him the best in his new position!

by Elizabeth Molina-Markham