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EpiGeneSys—a consortium of like-minded individuals who are passionate about the science of epigenetics and believe in the importance of conveying the findings of our research to the public.

20 February, 2013

By Jane Mellor, and Edith Heard

Research over the past century in genetics, developmental biology and more recently genomics, has led to the realization that DNA sequence cannot be the sole agent of heredity. Although heredity is firmly based on genetics, it is not always possible to predict phenotype from genotype and the relatively young discipline of epigenetics fills this gap. Epigenetics deals with the changes in gene expression that occur during development. All of our cells have the same genome – but different epigenomes and gene expression patterns. When a cell starts to express genes specific for a tissue, such as skin, or nerves – it does not usually change its mind or forget! It somehow remembers to keep expressing the right genes and to silence others – again, thanks to epigenetics.

Epigenetics also concerns the impact that the environment can have on phenotype without affecting genotype, both within, and across generations. Some of the changes that occur during ageing or in disease are now recognised as being epigenetic. The study of epigenetics includes both cell-to-cell transmission of epigenetic variants during an individual’s lifetime and trans-generational inheritance (1). Epigenetic mechanisms also explain the differential treatment of identical DNA sequences in a cell nucleus. For example some of our genes are imprinted - only expressed from the copy inherited from dad or mum. Another example concerns the shutting down of one of the two X chromosomes in females – a process known as X-chromosome inactivation, whereby an entire chromosome is stably silenced while its genetically identical homolog remains active.

Epigenetic mechanisms are also crucial for the stability of our genomes. They ensure stable repression of parasitic DNA such as transposable elements, which if left uncontrolled could wreak havoc in the genome. The notions of heritability and memory are implicit in most modern definitions of epigenetics – however reversibility is also a key component with important implications for disease as epigenetic changes can be reversed by treatment with drugs, unlike genetic lesions, which are irreversible. There is also a growing realisation of the impact that epigenetic changes can have on population genetics and on evolution.  EpiGeneSys is a consortium of like-minded individuals who are passionate about the science of epigenetics and believe in the importance of conveying the findings of our research to the public.

On this web site you will find accessible articles describing the latest advances in our understanding of how epigenetics impacts certain diseases and syndromes and an introduction to how the EpiGeneSys network is applying the most recent research tools to enhance our knowledge.

References:

1. Bird A (2007) Perceptions of epigenetics. (Translated from eng) Nature 447(7143):396-398 (in eng).

2. C. H. Waddington, Canalization of development and genetic assimilation of acquired characters. Nature 183, 1654 (Jun 13, 1959)

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