In order to ensure that the genetic material is duplicated and segregated accurately, cells have evolved a number of mechanisms to control the timing and order of events during cell division. One of these mechanisms is the bookmarking of genes prior to cell division.
Bookmarking genes involves the modification of histones, the proteins around which DNA is wrapped to form chromatin. These modifications make the chromatin more accessible to the proteins that are required for DNA replication and transcription. As a result, bookmarked genes are more likely to be replicated and transcribed during cell division.
The bookmarking of genes prior to cell division hastens their subsequent reactivation because it allows the cell to quickly and efficiently access the genetic information that is required for cell division. This is especially important for genes that are essential for cell cycle progression, such as the genes that encode cyclins and cyclin-dependent kinases.
By bookmarking essential genes prior to cell division, cells can ensure that these genes are expressed at the appropriate time and in the correct order, which is crucial for the accurate transmission of genetic information from one generation of cells to the next.
