Our Science

Susan M. Janicki, Ph.D.

Susan M. Janicki, Ph.D.

  • Associate Professor, Molecular and Cellular Oncogenesis Program
  • Scientific Director, Imaging Facility
  • 215-495-6850, Office
  • 215-495-6851, Lab

Genes are regulated by a series of interconnected processes, which we typically disassemble to examine in molecular detail.  However, we are beginning to accumulate evidence that these mechanisms are cooperative, dynamic and compartmentalized, making it necessary to study them in living cells.  To do this, we have developed a system that allows a specific region of chromatin to be visualized as it undergoes transcriptional activation.  For the first time, factor recruitment, RNA expression and chromatin structural changes can be probed simultaneously at a transcription site in a single cell.  By analyzing time-lapse images of these events, it is possible to gain an entirely new view of gene expression and identify novel regulatory mechanisms.  Accessing information about the dynamic aspects of gene expression is allowing us to understand the foundational principles of gene regulation.

Dr. Janicki joined The Wistar Institute in 2005 after finishing her postdoctoral fellowship at Cold Spring Harbor Laboratory in New York. She received her bachelor’s degree in biology and English from Tufts University in Massachusetts in 1993, and her Ph.D. from the University of Maryland in Baltimore in 1999.  In 2005, Dr. Janicki received the prestigious Beckman Young Investigator Award, and in 2007, she received the Basil O'Connor Starter Scholar Research Award from the March of Dimes Foundation.

Selected Publications

1.    Newhart A and Janicki SM. Seeing is Believing: Visualizing Transcriptional Dynamics in Single Cells. (2013) Journal of Cellular Physiology. [Aug 8; Epub ahead of print] PMID: 23929405

2.    Newhart A, Rafalska-Metcalf IU, Yang T, Joo LM, Powers SL, Kossenkov AV, Lopez-Jones M, Singer RH, Showe LC, Skordalakes E, and Janicki SM. Single-cell analysis of RNA-mediated histone H3.3 recruitment to a cytomegalovirus promoter-regulated transcription site. (2013) Journal of Biological Chemistry. July 5;288(27):19882-99. Epub 2013 May 20. PMID: 23689370

3.    Newhart A, Negorev DG, Rafalska-Metcalf IU, Yang T, Maul GG and Janicki SM.  Sp100A promotes chromatin decondensation at a CMV-promoter regulated transcription site. (2013) Molecular Biology of the Cell. May;24(9):1454-68. Epub 2013 March 13. PMID: 23485562

4.    Rafalska-Metcalf IU and Janicki SM. (2013) Preparation of Cell Lines for Single-Cell Analysis of Transcriptional Activation Dynamics. In: Gene Regulation: Methods and Protocols. Minou Bina, editor. Humana Press, New York. 977:249-58. PMID: 23436368

5.    Newhart A, Rafalska-Metcalf IU, Yang T, Negorev DG, and Janicki SM.  Single cell analysis of Daxx and ATRX-dependent transcriptional repression. (2012) Journal of Cell Science. Nov 15;125(Pt 22):5489-501. Epub 2012 Sep 12. PMID: 22976303

6     Rafalska-Metcalf IU, Powers SL, Joo LM, LeRoy G, Janicki, SM., Single cell analysis of transcriptional activation dynamics., PLoS One. 2010 Apr 21;5(4):e10272., 20422051