DNA methylation and childhood adversity

This 2017 Georgia human review covered: “Recent studies, primarily focused on the findings from human studies, to indicate the role of DNA methylation in the associations between childhood adversity and cardiometabolic disease in adulthood. In particular, we focused on DNA methylation modifications in genes regulating the hypothalamus-pituitary-adrenal axis as well as the immune system.” Recommendations … Continue reading DNA methylation and childhood adversity

Epigenetics research and evolution

This 2017 UK essay was a longish review of how epigenetics and other research has informed evolutionary theory: “There are several processes by which directed evolutionary change occurs – targeted mutation, gene transposition, epigenetics, cultural change, niche construction and adaptation. Evolution is an ongoing set of iterative interactions between organisms and the environment. Directionality is … Continue reading Epigenetics research and evolution

A review of biological variability

This 2017 UK/Spanish review subject was biological variability: “No two cells in a cellular population are the same, and no two individuals of a multi-cellular species are identical-not even if they share the same genetic makeup like monozygotic twins or cloned animals. Epigenetic and gene expression variability are key contributors to phenotypic differences. There are … Continue reading A review of biological variability

Does a societal mandate cause DNA methylation?

This 2017 worldwide meta-analysis of humans of recent European ancestry found: “Here we provide evidence on the associations between epigenetic modifications-in our case, CpG methylation and educational attainment (EA), a biologically distal environmental factor that is arguably among the most important life-shaping experiences for individuals. Specifically, we report the results of an epigenome-wide association study [EWAS] … Continue reading Does a societal mandate cause DNA methylation?

Epigenetic consequences of early-life trauma: What are we waiting for?

This 2015 UK human review discussed: “The progress that has been made by studies that have investigated the relationship between depression, early trauma, the HPA axis and the NR3C1 [glucocorticoid receptor] (GR) gene. Gene linkage studies for depression, as well as for other common complex disorders, have been perceived by some to be of only … Continue reading Epigenetic consequences of early-life trauma: What are we waiting for?

Improved methodology in studying epigenetic DNA methylation

This 2015 New York human study was of: “The two major populations of human prefrontal cortex neurons..the excitatory glutamatergic projection neurons and the inhibitory GABAergic interneurons which constitute about 80% and 20% of all cortical neurons, respectively. Major differences between the neuronal subtypes were revealed in CpG, non-CpG and hydroxymethylation (hCpG). A dramatically greater number … Continue reading Improved methodology in studying epigenetic DNA methylation

A problematic study of DNA methylation in frontal cortex development and schizophrenia

This 2015 Baltimore human study found: “CpGs that differ between schizophrenia patients and controls that were enriched for genes related to development and neurodifferentiation. The schizophrenia-associated CpGs strongly correlate with changes related to the prenatal-postnatal transition and show slight enrichment for GWAS [genome-wide association study] risk loci while not corresponding to CpGs differentiating adolescence from … Continue reading A problematic study of DNA methylation in frontal cortex development and schizophrenia

Genetic statistics don’t necessarily predict the effects of an individual’s genes

I curated this 2015 Howard Hughes Medical Institute rodent study of DNA methylation because of the reason driving the researchers’ efforts: “Epigenomic analyses are limited by averaging of population-wide dynamics and do not inform behavior of single cells. We observe dynamics at the single-cell level not predicted by epigenomic analysis.” This rationale was also the … Continue reading Genetic statistics don’t necessarily predict the effects of an individual’s genes

Changing an individual’s future behavior even before they’re born

This 2015 Harvard fruit fly research was a companion of the Is what’s true for a population what’s true for an individual? study. The researchers began with the question: “If we could rear genetically identical individuals from a variety of genetic backgrounds and rear them in the same environment, how much phenotypic variation between individuals … Continue reading Changing an individual’s future behavior even before they’re born

Is what’s true for a population what’s true for an individual?

This 2015 Harvard fruit fly study found: “Genetically identical individuals display variability in their behaviors even when reared in essentially identical environments. Individual flies exhibit significant bias in their left vs. right locomotor choices during exploratory locomotion.” Here’s an example of why population statistics such as in GWAS didn’t necessarily apply to an individual: “The … Continue reading Is what’s true for a population what’s true for an individual?