Epigenetics in simple terms is the study of changes in gene expression or activities, caused by mechanisms other than changes in the underlying DNA sequence.
As per the classical evolutionary theory, the changes in DNA and genes take place through natural selection process very slowly over many generations. Yet it is seen that under certain conditions, there are alterations in gene activity that do not lead to genetic code changes but these alterations are passed on to succeeding generation or generations.
The patterns of gene activity or expression are controlled by epi-genome which is on the top of genome, but outside it.
In a recent study, the researchers at King’s College London in collaboration with the Wellcome Trust Sanger Institute have found that a group of genes related to the aging process might be controlled by switching them on or off by mechanisms called epigenetic factors. This affects aging process and potential longevity.
The epigenetic processes that may be triggered or caused by external factors like diet, life style and environment may start from early ages and continue throughout one’s life. The researchers identified the epigenetic changes which could be used as markers of biological ageing and possibly utilised for anti-ageing therapies.
172 twins in the age range 32 to 80 at King’s college London and ST. Thomas’ hospital were studied. The epigenetic changes in the twins were examined and epigenome-wide association scans were performed by the researchers to analyse these changes in relation to chronological age.
“The researchers identified 490 age related epigenetic changes, analysed DNA modifications in age related traits and found that epigenetic changes in four genes relate to cholesterol, lung function and maternal longevity.”
The study was repeated with another set of 44 younger twins in the age range of 22 to 61 and many of the 490 age related epigenetic changes were observed in the younger group also. As per the researchers, this indicated that though epigenetic changes occur throughout one’s life, many of these set in during the early stages of life.
Jordna Bell who was the co-leader of the study said that epigenetic changes were linked to age related traits which were previously used to define biological age.
“We identified many age-related epigenetic changes, but four seemed to impact the rate of healthy ageing and potential longevity and we can use these findings as potential markers of ageing.
These results can help understand the biological mechanisms underlying healthy ageing and age-related disease, and future work will explore how environmental effects can affect these epigenetic changes,” Bell said.
[Source: This write up was sourced from the article “Switching off ‘ageing genes a potential anti-aging therapy’ in Z News.com updated Friday, April 20, 2012 and Wikipedia]