Student Profiles - 2005

Steven Petesch
Lis Lab
BMCB Field (entered program fall 2005)

From: Seattle, Washington
Undergraduate: Harvey Mudd College, Claremont, CA
B.S. in Chemistry (with Distinction) 2005

Statement

Coming from a small liberal arts college that focuses on math and science I knew that I wanted to continue on in a Ph.D. program that would not only challenge me but would also develop my skills as a research scientist and a mentor to others. After visiting, I learned that Cornell would provide both a challenge and the skills that I needed but would do so in a unique way. I felt that the BMCB field offered a highly collaborative environment whose professors support the growth and success of their graduate students through continued interactions and attention in a way that reminded me of my rewarding undergraduate experience.

Research

In the Lis lab we use in vivo techniques to study the molecular mechanisms of transcription. One ubiquitous barrier that the transcriptional machinery (Pol II) must overcome to efficiently transcribe genes is imposed by nucleosomes and higher order chromatin structures. How Pol II is able to overcome this barrier has been a long standing question and is the focus of my research in the Lis lab. To try and answer this question I use high-resolution micrococcal nuclease mapping and chromatin immunoprecipitation to track the position and composition of nucleosomes in vivo. These techniques provide the high spatial and temporal resolution needed to address how nucleosomes are changing as transcription is activated. Additionally, I employ other techniques such as RNAi and chemical inhibition that allow me to interrogate how a specific factor affects chromatin structure in vivo.

Publications

Ardehali MB, Yao J, Adelman K, Fuda NJ, Petesch SJ, Webb WW, Lis JT (2009) "Spt6 enhances the elongation rate of RNA polymerase II in vivo." EMBO J 28(8):1067-77, 2009.

Petesch SJ and Lis JT (2008) "Rapid, Transcription-Independent Loss of Nucleosomes over a Large Chromatin Domain at Hsp70 Loci." Cell 134(1): 74-84. (PubMed)

Van Ryswyk H, Hall EW, Petesch SJ, Wiedeman AE (2007) "Extending the Marine Microcosm Laboratory." Journal of Chemical Education 84: 306-309.

Presentations/Posters/Abstracts

Conferences Attended

Steven Petesch and John Lis. 2008. Extensive nucleosome disruption prior to RNA Polymerase II passage across the entire Drosophila Hsp70 gene. FASEB Summer Research Conferences: Transcriptional Regulation During Cell Growth, Differentiation and Development. Poster Presentation. June 22-27, 2008. Snowmass, CO.

Steven Petesch and John Lis. 2007. Mapping the nucleosome structure at Drosophila Hsp70 gene at high resolution. 26th Summer Symposium in Molecular Biology: Chromatin and Epigentic Regulation of Transcription. June 19-22, 2007. Penn State University Park Campus, PA.

Steven Petesch, Karl A. Haushalter. 2005. How does the DNA glycosylase MutY repair nucleosomal DNA?. 229th National Meeting of the American Chemical Society. Poster Presentation. March 13-17, 2005. San Diego, CA.

Conferences not Attended

Behfar Ardehali, Chris Fecko, Nick Fuda, John Lis, Zhuoyu Ni, Steven Petesch, Abbie Saunders, Watt W. Webb, and Jie Yao. Dynamics of Transcription and Chromatin at Specific Genes in vivo. Cold Spring Harbor Laboratory Meeting on the Mechanisms of Eukaryotic Transcription. August 29-September 2, 2007. Cold Spring Harbor, NY.

Katherine Kieckhafer, John T. Lis, Steven Petesch, Watt W. Webb, Jie Yao, and Katie Zobeck. The Dynamics of Transcription Factors and Chromatin Specific Loci Upon Gene Activation. Keystone Symposia Conference on the Regulatory Mechanisms in Eukaryotic Transcription. February 3-8, 2008. Keystone, CO.

Awards

“Outstanding Graduate Teaching Assistant” in the department of Molecular Biology and Genetics in May 2007.

Stephanie Yazinski
Weiss Lab
BMCB Field (entered program in fall 2005)

From: Moosic, Pennsylvania
Undergraduate: University of Scranton, Scranton, PA; BS (Biochemistry, Biomathematics) in 2005

Statement

I chose the BMCB program because of the diversity of labs that belong to this field. The program allowed me to rotate in three very different labs working with three different organisms to find a lab that best suited my interests.  The diversity also allows for several collaborations within the department. In addition, the BMCB program provides an opportunity to give scientific presentations at least once a year at the field seminar series.

Research

The Weiss Lab is interested in mechanisms of maintaining genomic stability, cellular responses to genome maintenance, and mouse models of cancer. My project involves elucidating roles for the DNA damage checkpoint protein Hus1 in cell transformation and tumor development in mice using several mouse models of cancer. In addition, I am utilizing the conditional Hus1 allele developed by our lab to examine the requirements for the DNA damage checkpoint protein Hus1 in the mouse mammary gland.

Awards

Department of Defense Predoctoral Traineeship Award              2008-2011
BMCB NIH Competitive Training Grant                                    2007-2008
BBS symposium poster competition                                       August 2008

Publications

Yazinski, S.A., Westcott, P.M., Ong, K., Pinkas, Y., Peters, R.M., and Weiss, R.S. Chromosomal Instability and p53-independent Apoptosis Following
Conditional Inactivation of the DNA Damage Checkpoint Gene Hus1 in the
Mouse Mammary Gland (Manuscript submitted)

Levitt, P.S., Zhu, M., Cassano, A., Yazinski, S.A., Liu, H., Darfler, J., Peters, R.M., and Weiss, R.S. (2007) Genome maintenance defects in cultured cells and mice following partial inactivation of the essential cell cycle checkpoint gene Hus1. Mol. Cell. Biol. 27: 2189-2201.

Conferences

Stephanie A. Yazinski, Peter Westcott, Kelly Ong, Yan Pinkas, Rachel Peters, and Robert S. Weiss. Chromosomal Instability and p53-independent Apoptosis Following Conditional Inactivation of the DNA Damage Checkpoint Gene Hus1 in the Mouse Mammary Gland Eleventh Annual Buffalo DNA Replication and Repair Symposium. January 2009. (poster presentation).

Stephanie A. Yazinski, Peter Westcott, Kelly Ong, Yan Pinkas, Rachel Peters, and Robert S. Weiss. Requirements for the DNA damage checkpoint protein Hus1 in the mouse mammary gland. Eleventh Annual Buffalo DNA Replication and Repair Symposium. May 2008. (poster presentation).

Stephanie A. Yazinski, Peter Westcott, Kelly Ong, Houchun Liu, and Robert S. Weiss. Requirements for the DNA damage checkpoint protein Hus1 in the mouse mammary gland. Eleventh Annual Buffalo DNA Replication and Repair Symposium. June 2007. (poster presentation).