The Air noncoding RNA: an imprinted cis-silencing transcript

Genomic imprinting is briefly defined as parental-specific gene expression. It is a feature of organisms withdiploid cells that have inherited a complete haploid chromosome set from two parents and, thereby, have a maternal and paternal allele for each autosomal gene. Diploidcells would normally be expected to express both parentalalleles equally but imprinted genes are different, becausethey acquire an epigenetic mark from one parental gamete that results in repression on one parental allele andexpression from the other. Genomic imprinting uses anepigenetic mechanism (i.e., a reversible modification toDNA or chromatin) to regulate gene expression in cis thatis assumed to be at the level of transcriptional, but this isnot often tested...