Allele-specific gene expression and epigenetic modifications and their application to understanding inheritance and cancer.

Epigenetic information is characterized by its plasticity during development and differentiation as well as its stable transmission during mitotic cell divisions in somatic tissues. This duality contrasts to genetic information, which is essentially static and identical in every cell in an organism with only a few exceptions such as immunoglobulin genes in lymphocytes. Epigenetics is traditionally perceived as a means to regulate gene expression without a change in DNA sequence. This, however, does not exclude a potential role for genetic variations in providing differential backgrounds on which epigenetic modulations and their regulatory consequences are achieved. An effective approach to investigating the interplay between genetic variations and epigenetic variations is through allele-specific analysis of epigenetics and gene expression. Such studies have generated many new insights into functions of genetic variations, mechanisms of gene expression regulation, and the role of mutations and epigenetic alterations in human cancer. This article is part of a Special Issue entitled: Chromatin in time and space. Published by Elsevier B.V.