Researchers from Uppsala University have discovered a mechanism that silences several genes in a chromosome domain. The findings, published in today's on-line issue of Molecular Cell, have implications in understanding the human disorder Beckwith-Wiedemann syndrome.
In mammals the cells contain two copies of each chromosome, one inherited from the mother and one from the father. The genes on the chromosomes can either be active or inactive. If a gene is active on the maternal chromosome, the corresponding gene is usually active also on paternal chromosome. However, in some domains of the chromosome the activity is shut down on one of the chromosomes but not on the other. The genes in these domains cannot be activated the normal way but are completely silenced. The present study shows for the first time how this silencing of several genes on a chromosome is accomplished.