Credit Seminar On X-Chromosome Inactivation


In all biological systems, gene expression is exquisitely controlled. The cell devotes vast resources to ensure that a given gene is expressed not only at the proper time but also at the appropriate level. Inappropriate or ectopic dosages often have grave consequences that cause developmental delay and organism death. Changes to the genetic code are not the only factors that influence the expression but another system of influence on the expression of genes is referred to as epigenetics; a system that switches the genetic information on and off. The cells of the body contain the genes for the cell to make all the necessary products for our bodies to grow and work normally. X-inactivation is such a phenomenon that enables men and women to have equal expression of the genes carried on the X chromosome despite the fact that women have two X chromosome copies and men have only one in addition to a Y chromosome. The cellular system of X-inactivation ensures that only one copy of most of the X chromosome genes in a female cell is active. Most of the other genes on the other partner X chromosome copy are inactivated or switched off. X-chromosome inactivation is initiated by the formation of a conserved XIST transcript followed by the association/regulation by other factors like DNA methylation, histone modifications, antisense Tsix regulation, trans acting factors, macrohistone H2, replication timing which not only help in inactivation process but also help in the choice of chromosome and in stability of inactivation.

Student: Sonam Takkar, M.Tech IInd Year Genetic Engineering
Venue: B(404) Class room
Date & Time: 21/10/2011 & 1.30PM