Feb 2023
Abstract:
The silencing
of all but one X chromosome in mammals is a paradigm for epigenetic gene
control; with the X to be silenced chosen early in development and then
maintained silent across the lifespan. A long non-coding RNA XIST is
expressed from the inactive X and recruits repressive chromatin
including DNA methylation and histone modifications to silence genes on
the inactive X chromosome. However, not all genes are silenced – up to a
quarter of X-linked genes in humans continue to be expressed from the
'inactive' X. The Brown lab seeks to understand how XIST can silence a
chromosome and identify the DNA elements that allow some genes to
'escape' from the otherwise repressive chromatin of the inactive X
chromosome.
Bio:
Dr. Carolyn J. Brown, Ph.D.
obtained her Ph.D. in Medical Genetics from the University of Toronto
in 1990. During her Ph.D. and subsequent postdoctoral work with Dr.
H.F. Willard at Stanford and Case Western Reserve University, she
studied the process of X chromosome inactivation, identifying genes
expressed from the inactive X, including the XIST gene, which is a key
initiator of X chromosome silencing. She has been at the University of
British Columbia since 1994, where her research group continues to study
X-chromosome inactivation. They focus on the role of the XIST RNA in
initiating the heterochromatic changes that accompany human X-chromosome
silencing as well as the DNA elements that allow some genes to escape inactivation.