Jeannie Lee Part 1: Making and Breaking the Silence
In mammals, sex is determined by a pair of unequal sex chromosomes. Genetically male mammals have an X and a Y chromosome while genetically female mammals have two X chromosomes. The X chromosome is many times larger than the Y chromosome. To compensate for this genetic inequality, female mammals undergo X chromosome inactivation in which one of the X chromosomes is randomly chosen to be silenced. X chromosome inactivation has been studied for over 50 years both because it is a physiologically important event and because it is an excellent model for studying epigenetic silencing of genes by long non-coding RNAs. In her first talk, Dr. Jeannie Lee gives an overview of the steps a cell must go through during X inactivation. These include “counting” the X chromosomes, deciding which X chromosome to inactivate, initiating the inactivation and spreading it across the chromosome, and finally maintaining inactivation of the same X chromosome for the rest of the life of the organism.
View the full talk with additional resources on our website
The X chromosome is many time larger than the Y chromosome. To compensate for this genetic inequality, female mammalian cells undergo X chromosome inactivation of one X chromosome. Dr. Jeannie Lee explains the how and why of X chromosome inactivation. (Talk recorded in November 2018)
Dr. Jeannie Lee is a Professor in the Department of Genetics at Harvard Medical School and in the Department of Molecular Biology at Massachusetts General Hospital (MGH). Her lab uses X chromosome inactivation as a model to study epigenetic regulation by long noncoding RNAs. Lee received her AB in biochemistry and molecular biology from Harvard…