A new epigenetic mechanism through which the conditions at conception may affect the health of an individual in later life has been discovered by Tampere University scientists. The study, led by Finnish Academy Research Fellow Emma Raitoharju, shows that the family’s occupational status, income level and maternal age at conception are linked to specific molecular changes in offspring up to adulthood.
The link was detected in the DNA methylation in the region of the non-coding RNA 886 gene (nc886 gene).
“DNA methylation is an epigenetic mechanism that switches off gene expression. Gene expression regulates cell and tissue function. In this case, the chromosome inherited from the father is always unmethylated and expresses the nc886 gene in all humans,” says Saara Marttila, postdoctoral researcher and first author of the paper.
“The number of individuals whose maternal chromosome is also unmethylated and also expresses RNA appears to be lower in those born into families of highest socio-economic status and in those whose mothers were between 21 and 30 years old,” Marttila says.
The study shows that this early developmentally determined status of DNA methylation in the nc886 gene is stable from childhood to adulthood, throughout a 40-year follow-up. People with both chromosomes unmethylated have twice the amount of nc886 RNA in their blood, and the study also found direct evidence of this at the level of RNA expression over 30 years of follow-up.
“From a molecular biologist’s point of view, this is a beautiful example of epigenetic imprinting,” Marttila and Raitoharju say.
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The role of a single gene in the whole is small, but in this case the difference in the expression of nc886 is present in all tissues throughout life. The association with glucose and lipid metabolism suggests that this may play a role in an individual’s subsequent risk of disease.
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The data used in the study included, among other things, the follow-up data from the Young Finns Study, which has been running for 40 years, and the corresponding German KORA data.
Source-Eurekalert