Scientists discover how epigenetic information could be inherited

hps25 — Fri, 25 Jan 2013 13:25:47 +0000

New research reveals a potential way for how parents鈥� experiences could be passed to their offspring鈥檚 genes. 探花直播research was published today, 25 January, in the journal Science.

Epigenetics is a system that turns our genes on and off. 探花直播process works by chemical tags, known as epigenetic marks, attaching to DNA and telling a cell to either use or ignore a particular gene.

探花直播most common epigenetic mark is a methyl group. When these groups fasten to DNA through a process called methylation they block the attachment of proteins which normally turn the genes on. As a result, the gene is turned off.

Scientists have witnessed epigenetic inheritance, the observation that offspring may inherit altered traits due to their parents鈥� past experiences. For example, historical incidences of famine have resulted in health effects on the children and grandchildren of individuals who had restricted diets, possibly because of inheritance of altered epigenetic marks caused by a restricted diet.

However, it is thought that between each generation the epigenetic marks are erased in cells called primordial gene cells (PGC), the precursors to sperm and eggs. This 鈥榬eprogramming鈥� allows all genes to be read afresh for each new person 鈥� leaving scientists to question how epigenetic inheritance could occur.

探花直播new Cambridge study initially discovered how the DNA methylation marks are erased in PGCs, a question that has been under intense investigation over the past ten years. 探花直播methylation marks are converted to hydroxymethylation which is then progressively diluted out as the cells divide. This process turns out to be remarkably efficient and seems to reset the genes for each new generation. Understanding the mechanism of epigenetic resetting could be exploited to deal with adult diseases linked with an accumulation of aberrant epigenetic marks, such as cancers, or in 鈥榬ejuvenating鈥� aged cells.

However, the researchers, who were funded by the Wellcome Trust, also found that some rare methylation can 鈥榚scape鈥� the reprogramming process and can thus be passed on to offspring 鈥� revealing how epigenetic inheritance could occur. This is important because aberrant methylation could accumulate at genes during a lifetime in response to environmental factors, such as chemical exposure or nutrition, and can cause abnormal use of genes, leading to disease. If these marks are then inherited by offspring, their genes could also be affected.

Dr Jamie Hackett from the 探花直播 of Cambridge, who led the research, said: 鈥淥ur research demonstrates how genes could retain some memory of their past experiences, revealing that one of the big barriers to the theory of epigenetic inheritance 鈥� that epigenetic information is erased between generations 鈥� should be reassessed.鈥�

鈥淚t seems that while the precursors to sperm and eggs are very effective in erasing most methylation marks, they are fallible and at a low frequency may allow some epigenetic information to be transmitted to subsequent generations. 探花直播inheritance of differential epigenetic information could potentially contribute to altered traits or disease susceptibility in offspring and future descendants.鈥�

鈥淗owever, it is not yet clear what consequences, if any, epigenetic inheritance might have in humans. Further studies should give us a clearer understanding of the extent to which heritable traits can be derived from epigenetic inheritance, and not just from genes. That could have profound consequences for future generations.鈥�

Professor Azim Surani from the 探花直播 of Cambridge, principal investigator of the research, said: 鈥� 探花直播new study has the potential to be exploited in two distinct ways. First, the work could provide information on how to erase aberrant epigenetic marks that may underlie some diseases in adults.聽 Second, the study provides opportunities to address whether germ cells can acquire new epigenetic marks through environmental or dietary influences on parents that may evade erasure and be transmitted to subsequent generations, with potentially undesirable consequences.鈥�

Research reveals the mechanism of epigenetic reprogramming.

Our research demonstrates how genes could retain some memory of their past experiences, revealing that one of the big barriers to the theory of epigenetic inheritance - that epigenetic information is erased between generations - should be reassessed.

Jamie Hackett

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Scientists discover how epigenetic information could be inherited