Xantha Karp

Photo of Xantha KarpAssistant Professor 
Books Hall 183 (Office)
Brooks Hall 302 (Lab)
  • B.S., University of Toronto, 1995
  • Ph.D., Columbia University, 2004
Teaching Areas
​Cell Biology and Genetics
Research Fields
​Genetics, Developmental Biology, Cell Biology
Current Research Projects
The development of many stem cells and progenitor cells is interrupted by a period of quiescence, which is a reversible non-proliferating state. Quiescent progenitor cells must "remember" their precise place in their developmental program, neither differentiating prematurely, nor losing their tissue identity. We use the microscopic nematode C. elegans to investigate how this is accomplished. When young C. elegans larvae are cultured in adverse environmental conditions they pause their development by entering dauer quiescence, an arrested, non-aging and stress-resistant stage. If conditions improve, dauer larvae recover and complete development normally. This indicates that progenitor cells in wild-type dauer larvae maintain their developmental potential, or the ability to give rise to all proper cell types. My lab uses genetic screens to discover the mechanisms that enable the maintenance of developmental potential during dauer quiescence.
Selected Publications
  • Karp X., Greenwald I. (2013). Control of cell fate plasticity and maintenance of multipotency by DAF-16/FOXO in quiescent Caenorhabditis elegans. PNAS. 110: 2181-2186.
  • Karp X., Ambros V. (2012). Dauer larva quiescence alters the circuitry of microRNA pathways regulating cell fate progression in C. elegansDevelopment. 139: 2177-2186.
  • Karp X., Hammel M., Ow MC, Ambros V. (2011). Effect of life history on microRNA expression during C. elegans development. RNA. 17: 639-651.
  • Karp X., Ambros V. (2011). The developmental timing regulator hbl-1 modulates the dauer formation decision in C. elegansGenetics. 187(1): 345-353.
  • Hammell CM*, Karp X*, Ambros V. (2009). A feedback circuit involving let-7-family microRNAs and DAF-12 integrates environmental signals and developmental timing in C. elegansPNAS. 106(44): 18668-18673. *Equal contribution