Jeannie T. Lee
Department of Genetics (and Pathology)
Howard Hughes Medical Institute
Harvard Medical School
Massachusetts General Hospital - Simches Research Ctr. 6.624
Dept. of Molecular Biology
185 Cambridge St.
Boston, MA 02114
Tel: (617) 643-3043
Fax: (617) 726-6893
Email: lee@molbio.mgh.harvard.edu
Web Page: The Lee Lab Page
15 postdoctoral fellows, 4 graduate students, 1 visiting scientist
My laboratory studies how one of the sex chromosomes in mammals is inactivated. Known as “X-chromosome inactivation” (XCI), this process involves many intriguing regulatory events and players. XCI takes place in both males and females. In females, one of two Xs is inactivated in the virtually all tissues of the soma. In males, both X and Y chromosomes become inactivated in the germline. While female XCI is indisputably necessary to ensure equal X-chromosome dosage between the sexes, why male germline XCI is necessary has been subject to colorful debate. We are interested in all aspects of these epigenetic phenomena. Some examples of what we study include how the counting mechanism works, how/why the X-chromosomes transiently pair just before silencing takes place, and how various noncoding RNAs (Xist, Tsix, and Xite) drive the control of X-chromosome choice and silencing. We are also interested in drawing molecular and evolutionary parallels between XCI and genomic imprinting and RNAi.
References:
- Xu, N., Tsai, C.L., and Lee, J.T. (2006) Transient homologous chromosome pairing marks the onset of X inactivation. Science 311, 1149-1152.
- Sun, B.K., Deaton, A., and Lee, J.T. (2006) A transient heterochromatic state in Xist preempts and predicts X-inactivation choice without RNA stabilization. Molecular Cell 21, 617-628.
- Cohen, D.E., Davidow, L.S., Erwin, J.A., Xu, N., Warshawsky, D., and Lee, J.T. (2007) The DXPas34 repeat regulates random and imprinted X-inactivation. Developmental Cell 12, 57-71.
- Donohoe, M.E., Zhang, L.F., Xu, N., Shi, Y., and Lee, J.T. (2007) Identification of a Ctcf co-factor for the X-chromosome binary switch. Molecular Cell 25, 43-56.
- Zhang, L.F., Huynh, K.D., and Lee, J.T. (2007) Perinucleolar targeting of the inactive X during S phase: Evidence for a role in the maintenance of silencing. Cell 129, 693-706.
- Namekawa, S.H., Vandeberg, J.L., McCarrey, J.R., and Lee, J.T. (2007) Sex chromosome silencing in the marsupial male germ line. Proc. Natl Acad. Sci. USA, May 29, 2007- Epub ahead of print.
- Xu, N. †, Donohoe, M.E. †, Silva, S.S., and Lee, J.T. (2007) Evidence for a role of transcription and Ctcf protein in homologous X-chromosome pairing. Nature Genetics 39,1390-1396.
BBS webpage updated 12/02/2009