Genomic imprinting and random monoallelic expression

In this review we consider mechanisms of monoallelic expression: genomic imprinting, in which gene transcription depends on the parental origin of the allele, and random monoallelic transcription. We summarize evidence for the regulation of activity in imprinted regions. Particular attention is paid to areas that control imprinting. Factors that may influence the variability of the imprintome are considered. The perspectives behind monoallelic expression studies are also discussed.