Genomic imprinting is a genetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner. It is an inheritance process independent of the classical Mendelian inheritance. Imprinted alleles are silenced such that the genes are either expressed only from the non-imprinted allele inherited from the mother (e.g. H19 or CDKN1C), or in other instances from the non-imprinted allele inherited from the father (e.g. IGF-2). Forms of genomic imprinting have been demonstrated in insects, mammals and flowering plants.
Genomic imprinting is an epigenetic process that involves DNA methylation and histone modifications in order to achieve monoallelic gene expression without altering the genetic sequence. These epigenetic marks are established in the germline and are maintained throughout all somatic cells of an organism.
Appropriate expression of imprinted genes is important for normal development, with numerous genetic diseases associated with imprinting defects including Beckwith–Wiedemann syndrome, Silver–Russell syndrome, Angelman syndrome and Prader–Willi syndrome.
Read more about Genomic Imprinting: Overview, Imprinted Genes in Mammals, Imprinted Genes in Plants
Famous quotes containing the word imprinting:
“Once I pass’d through a populous city imprinting my brain for
future use with its shows, architecture, customs, traditions,
Yet now of all that city I remember only a woman I casually met
there who detain’d me for love of me,”
—Walt Whitman (1819–1892)