Epigenetic inheritance: the influence of variable silencing of the repeat genome. (360G-Wellcome-210757_Z_18_Z)
Evidence from epidemiological studies and experiments in animal models suggests that effects of environment and lifestyle can be transmitted across generations via non-genetic mechanisms. Such mechanisms are challenging to unravel in mouse and man. In mammals, non-genetic inheritance is best exemplified by the Agouti viable yellow (Avy) mouse where phenotypic differences in genetically identical animals are caused by insertion of a retrotransposon - an endogenous retrovirus (ERV) that provides a cryptic promoter driving ectopic expression of agouti. This ERV is variably DNA methylated in different individuals causing inter-individual variation in coat colour – a non-genetic influence on phenotype. Remarkably, a memory of parental coat colour is transmitted to subsequent generations. Variable expressivity can be modulated by in utero environmental exposures. ERVs represent ~12% of the mouse genome. Inspired by Avy, we propose a research programme, supported by preliminary data, to address the following questions: Aim 1 – To what extent do mammalian ERVs exhibit variable epigenetic silencing and what is the mechanism? Aim 2 – Is this transmitted as non-genetic memory across generations? Aim 3 – Are they sensors of environmental compromise? Aim 4 – Are there implications for phenotype? Aim 5 – Does a related phenomenon occur in humans?
£2,929,851 10 Apr 2018