Early life experiences can impact the activity of our genes much later on and even affect longevity, finds a new study in fruit flies.
According to the study, led by University College London (UCL), UK, the scientists report that gene expression 'memory' can persist across the lifespan, and may present a novel target for improving late-life health.
Gene expression refers to the conversion of the information encoded in a gene first into messenger RNA and then to a protein.
The scientists were building on their previous research in which they found that fruit flies fed a high-sugar diet early in life lived shorter lives, even after their diets were improved in adulthood. Here, the study said, they uncover the mechanism likely explaining the finding.
"Health in old age partially depends on what a person experienced in their youth or even in the womb. Here, we have identified one way in which this happens, as changes in gene expression in youth can form a 'memory' that impacts health more than half a lifetime later," said Dr. Nazif Alic, lead author of the study, UCL.
In their previous study, the researchers found that a high-sugar diet inhibited a transcription factor called dFOXO, which is involved in glucose metabolism and is known from multiple studies to affect longevity, so they now sought to enact the opposite effect by directly increasing the activity of dFOXO, the study said.
Transcription factors are proteins that regulate transcription, or copying, of information from DNA into messenger RNA, which is the first and key step in gene expression. Messenger RNA is a form of RNA that carries information from DNA in the nucleus to the cytoplasmic sites of protein synthesis in the cell.
For this study, the researchers activated dFOXO by increasing its levels in female fruit flies during the first three weeks of the fly's adulthood.
The scientists found that these early-life experiences caused changes to chromatin - a mixture of DNA and proteins that can be seen as the 'packaging' of DNA - that persisted and resulted in genes being expressed differently late in life.
This counteracted some changes that would be expected as part of the normal ageing process. These changes would eventually improve health in late life and impact the fruit flies' lifespan for more than a month, which is equal to half a fruit fly lifetime, later, the study said.
The researchers say their findings could lead to ways to impact late-life health in people as well.
"What happens early on in an animal or person's life can affect what their genes do late in life, for better or for worse.
"It may be that a poor diet early in life, for example, could impact our metabolism later in life by tweaking how our genes are expressed, even after substantial dietary changes over the years - but fortunately, it may well be possible to reverse this," said Alic.
"Now that we know how gene expression memory can persist across the lifespan to affect gene activity, we may be able to develop ways to counteract these changes later in life to preserve health and enable people to stay healthy for longer," said Alic.
- The scientists report that gene expression 'memory' can persist across the lifespan, and may present a novel target for improving late-life health.
- Early-life experiences caused changes to chromatin - a mixture of DNA and proteins that can be seen as the 'packaging' of DNA - that persisted and resulted in genes being expressed differently late in life.
- The researchers say their findings could lead to ways to impact late-life health in people as well.