Cells Can Randomly Use One Copy of a Gene Over the Other (image) Cold Spring Harbor Laboratory Share Print E-Mail Caption The nucleus of every cell in our body contains two copies of each gene, encoded in our DNA (nuclei outlined in purple, DNA for individual genes labeled in red). In general, these copies are used equally, but on occasion, the cell chooses to use just one (seen here in yellow/green). Today, researchers from CSHL have discovered that this truly random process, known as monoallelic gene expression, occurs during development, offering an unexpected glimpse of the significant variability in gene expression. Credit David Spector, Cold Spring Harbor Laboratory Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.