Sarah Siegrist

Assistant Professor of Biology
316 PLSB
(434) 982-2604
Lab: (434) 243-4328

Education

  • B.S. Miami University, Oxford Ohio, 1990
  • PhD University of Oregon, Eugene, OR, 2005
  • Post-doctoral research University of California, Berkeley, CA 2006-2012

Research Interests

The sheer number and diversity of cell types within the human brain is staggering. Understanding how cellular diversity is generated and organized in such a way that allows organisms to think and behave is of fundamental importance. All neurons within the brain are generated from neural stem cells, which are self-renewing multipotent progenitors. Neural stem cells play a key role in regulating brain size and cell type diversity, since this population remains actively engaged in the cell cycle throughout development. While much effort is geared towards identifying molecular mechanisms regulating stem cell self-renewal, I have become fascinated by the converse. What are the molecular mechanisms that terminate neural stem cell divisions once development is complete, which is essential for ensuring proper formation of brain circuitry and to inhibit tissue overgrowth and tumorigenesis. Beyond development, the answer to this fundamental question is of key importance for understanding age-related cognitive declines, mood disorders, and limited regenerative capacity of adult brains. In the Siegrist lab, we are working on understanding:

                (1) Regulation of neural stem cell proliferation by extracellular factors, local and systemic.

                (2) Intrinsic signaling programs regulating neural stem cell fate decisions: death versus survival.

                (3) Functional and molecular similarities between Drosophila and mammalian neural stem cells.  

Representative Publications

  • Siegrist, S.E., Haque, N.S., Chen, C., Hay, B.A., and Hariharan, I.K. (2010). Inactivation of both foxo and reaper promotes long-term adult neurogenesis in Drosophila. Current Biology, 13; 20(7):643-  8. PMID: 20346676.
     
  • Siegrist, S.E. and Doe, C.Q. (2007). Microtubule-induced cortical cell polarity. Genes and Development 21(5). Review. PMID: 17344411.
     
  • Lee, C.Y., Wilkinson, B.D., Siegrist, S.E., Wharton, R.P., and Doe, C.Q. (2006). Brat is a Miranda cargo protein that promotes neuronal differentiation and inhibits neuroblast self-renewal.  Developmental Cell, 10(4):441-9. PMID: 16549393.
     
  • Siegrist, S.E. and Doe, C. Q. (2006). Extrinsic cues orient the cell division axis in Drosophila embryonic neuroblasts. Development, 133(3):529-36. PMID: 16396904.
     
  • Siegrist, S.E. and Doe, C.Q. (2005). Microtubule-induced Pins/Gai cortical polarity in Drosophila neuroblasts. Cell, 123(7):1323-35. PMID: 16377571.