Epigenetic information can be passed on from one generation to another via DNA methylation, histone modifications, and changes in small RNAs, a process called epigenetic memory. During a mammal’s lifecycle epigenetic reprogramming, or the resetting of most epigenetic marks, occurs twice. The first instance of reprogramming occurs in primordial germ cells and the second occurs following fertilization. These processes may be both passive and active. In order for epigenetic inheritance to occur the epigenetic modifications must be able to escape reprogramming. There are several examples supporting this non-Mendelian mechanism of inheritance including the prepacking of early developmental genes in histones instead of protamines in sperm, genomic imprinting via methylation marks, the retention of CenH3 in mammalian sperm and the inheritance of piwi-associated interfering RNAs. The ability of mammals to pass on epigenetic information to their progeny provides clear evidence that inheritance is not restricted to DNA sequence and epigenetics plays a key role in producing viable offspring.
Keywords: epigenetic memory, germ line reprogramming, genomic imprinting, epigenetic inheritance, epigenetic disease inheritance
Citation: Migicovsky Z and Kovalchuk I (2011) Epigenetic memory in mammals. Front. Gene. 2:28. doi: 10.3389/fgene.2011.00028
Received: 28 April 2011;
Paper pending published: 15 May 2011;
Accepted: 26 May 2011; Published online: 08 June 2011.
Edited by:Jaap Joles, University Medical Center Utrecht, Netherlands
Reviewed by:Rachel Giles, University Medical Center Utrecht, Netherlands
Copyright: © 2011 Migicovsky and Kovalchuk. This is an open-access article subject to a non-exclusive license between the authors and Frontiers Media SA, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and other Frontiers conditions are complied with.
*Correspondence: Igor Kovalchuk, Department of Biological Sciences, University of Lethbridge, 4401 University Drive, Lethbridge, Canada AB T1K 3M4. e-mail: email@example.com