Discussion: Nature Versus Nurture: Epigenetics and the Microbiome
Epigenetics is the study of changes in gene activity that do not involve direct alterations to the actual genetic code. There is a relationship between genes and traits, and the bridge between the gene or genes underlying a trait is a protein. Genes are the code for building proteins, and once built, proteins carry about many functions in the body and they are ultimately responsible for behavioral traits. How is it decided what specific genes get turned on or off? The patterns of gene expression (protein manufacture) are governed by the cellular materialthe epigenomethat sits on top of the genome, just outside it (hence the prefix , which means above). It is these epigenetic “marks” that tell certain genes to switch on or off. It is through epigenetic marks that environmental factors like diet, stress, and prenatal nutrition can make an imprint on genes, and this imprint can be passed on over generations. With epigenetic changes, the DNA itself does not change, but the way individual genes within the sequence are expressed (or turned on or off) does change.
Alternatively, the infant microbiome has been shown to play a role in future health, and this is influenced by the exchange of maternal microbes. There is evidence that this is even linked to autism and other developmental aspects such as communication and cognitive performance.
To prepare:
Choose an area to focus your discussion: epigenetics OR the microbiome. You will then respond to a classmate who chose the one that you did not.
If you chose epigenetics, read about gene-by-environment effects (also called gene x environment or G X E) in the Champagne and Mashoodh (2009) article. The particular example you will examine is epigenetic programming due to variations in maternal care. Specifically, in rodent models, it was found that maternal behavior such as carefully licking and grooming the pups was tied to a decreased stress response and lower levels of exploration fear in the pups. Mothers that displayed low levels of pup licking and grooming had adult offspring with a heightened stress response. This study provided evidence that epigenetic changes can underlie the long-term impact of early life experiences.
For this Discussion, consider the personal and social implications of gene x environment interactions. Also consider other gene x environment interactions future research will be most likely to discover based on your introduction to this new topic.
If you chose the microbiome, read about how the infant gut microbiome is associated with brain development, cognitive development, mental health, including autism, language, and the immune system. For this Discussion, consider the personal and social implications of a healthy microbiome, both for you and infants that are yet to be born.
With these thoughts in mind:
By Day 3
Post your response to the following:
If you chose to write about Epigenetics: Explain how epigenetics provides a new perspective on the nature versus nurture debate. Also, reference the Champagne and Mashoodh (2009) article, and provide an explanation of how the rat-nurturing example can further explain human parental behavior. In addition, explain the broader social implications of this type of research. Finally, share your prediction of and rationale for what other gene x environment interactions future research may discover.
If you chose to write about the Microbiome: Explain how microbiome research provides a new perspective on the nature versus nurture debate. Discuss how the infant microbiome is related to future development of a child, including cognition and health. In addition, explain the broader social implications of this type of research. Finally, share your prediction of and rationale for what future microbiome research may discover.
