Marlene Lorgen-Ritchie is a postdoctoral research fellow at the Rowett Institute. Her research involves investigating the biological pathways linking the social environment during development, with mood and personality in later life.
Here, in the latest of our biosocial blog series, she writes about one aspect of biosocial research – epigenetics – which she’ll be exploring more at a Festival of Social Science event next week.
Our early life experiences in the womb and throughout childhood have been shown to influence how we turn out as adults. This includes how healthy we are, how rich we become and what and how we think. However we still don’t know how it all comes about biologically. That’s where epigenetics comes in.
DNA is the ‘blueprint for life’ and the DNA sequence forms the basis of genetics. However, epigenetics refers to information in the genome other than in the DNA sequence, for example chemical markers called methyl groups which can decide if a gene is switched on or off. Epigenetics can be influenced by the environment which leads us to the ‘nature vs nurture’ paradigm. Do our genes determine our fate in life or can our environment take control?
One type of epigenetics is imprinting. We get two copies of every gene, one from each parent, but in imprinting, only one copy remains switched on in the offspring while the other is ‘silenced’ by the addition of methyl groups to the DNA. Imprinting happens very early in human development and remains in place for life. Some conditions associated with impaired cognitive ability, such as Prader-Willi syndrome, are a result of improper imprinting.
We are currently working on a research project looking at the effects of the early social environment on imprinting and its relationship with cognition and mood in later life. To study life course epigenetics, we require a specific study design – that is, access to trials, experiments and other types of research involving human beings – which we have access to in the form of the Aberdeen Birth Cohorts of 1921 and 1936.
In 1932 and 1947, all children of age 11 attending school in Aberdeen sat the Moray House Test, basically an IQ test. In the Aberdeen Birth Cohorts, participants were followed up in later life (aged 65 and over) and undertook further cognitive testing, gave blood samples, completed questionnaires relating to their mood and lifestyle, and some even had brain scans. DNA was extracted from blood samples, from which we can obtain information about imprinting using state of the art techniques.
This project forms part of the work of the collaborative Epigenetics and Social Science Network (ESSN) in the area of biosocial research, which is joint funded by the Economic and Social Research Council (ESRC) and the Biotechnology and Biological Sciences Research Council (BBSRC). Our research is based at the Rowett Institute of the University of Aberdeen as we are working in collaboration with partners at the genetics department at Cambridge University and in cognitive epidemiology at University College London.
If you’re interested in learning more about life course epigenetics and cognition, join ‘Early life experiences and the adult mind’ – an event on 8 November 2017 hosted by the Rowett Institute as part of the ESRC Festival of Social Science.
You can also follow @EpiSocSciNet on Twitter.