This 2019 UK human study conducted a meta-analysis of genome-wide association studies of two epigenetic clocks using 13,493 European-ancestry individuals aged between ten and 98 years: “Horvath-EAA, described in previous publications as ‘intrinsic’ epigenetic age acceleration (IEAA), can be interpreted as a measure of cell-intrinsic ageing that exhibits preservation across multiple tissues, appears unrelated to … Continue reading A GWAS meta-analysis of two epigenetic clocks
This 2017 Colorado analysis, “No Evidence That Schizophrenia Candidate Genes Are More Associated With Schizophrenia Than Noncandidate Genes,” found: “A recent analysis of 25 historical candidate gene polymorphisms for schizophrenia in the largest genome-wide association study [GWAS] conducted to date suggested that these commonly studied variants were no more associated with the disorder than would be … Continue reading The truth about complex traits and GWAS
This 2020 rodent study from the labs of Dr. Michael Skinner at Washington State University examined how great-grandmothers’ insect repellent exposures produced diseases in their great-grand offspring: “Permethrin and DEET are the pesticides and insect repellent most commonly used by humans. These pesticides have been shown to promote the epigenetic transgenerational inheritance of disease in … Continue reading DEET and permethrin cause transgenerational diseases
This 2020 Washington State University rodent study examined how great-grandmothers’ JP-8 exposures produced diseases in their great-grand offspring: “Ancestral exposure to environmental influences such as toxicants, abnormal nutrition, and traumatic stress can affect the germline epigenome and promote the epigenetic transgenerational inheritance of adult onset disease in various organisms from plants to humans. Biological mechanisms … Continue reading Jet fuel exposure causes diseases in the great-grand offspring
This 2019 McGill review discussed long-lasting effects of perinatal stress: “Epigenetic processes are involved in embedding the impact of early-life experience in the genome and mediating between social environments and later behavioral phenotypes. Since these phenotypes are apparent a long time after the early experience, the changes in gene expression programming must be stable. Although … Continue reading The epigenetics of perinatal stress
This 2019 Singapore human study used Diffusion Tensor Imaging on 5-to-17-day old infants to find: “Our findings showed evidence for region-specific effects of genotype and GxE on individual differences in human fetal development of the hippocampus and amygdala. Gene x Environment models outcompeted models containing genotype or environment only, to best explain the majority of … Continue reading Do genes or maternal environments shape fetal brains?
This 2019 US/UK human cell study by the founder of the epigenetic clock method investigated epigenetic aging: “It is widely assumed that extension of lifespan is a result of retardation of ageing. While there is no counter-evidence to challenge this highly intuitive association, supporting empirical evidence to confirm it is not easy to acquire. The … Continue reading What drives cellular aging?
This 2018 Chinese study was a series of statistical and methodological counter-arguments to a previous epigenetic clock study finding that: “Only [CpG] sites mapping to the ELOVL2 promoter constitute cell and tissue-type independent aDMPs [age-associated differentially methylated positions].” The study used external data sets and the newer epigenetic clock’s fibroblast data in its analyses to … Continue reading Epigenetic clock statistics and methods
This 2018 UK review discussed three pre-existing conditions of epigenetic genome-wide association studies: “Genome-wide technology has facilitated epigenome-wide association studies (EWAS), permitting ‘hypothesis-free’ examinations in relation to adversity and/or mental health problems. Results of EWAS are in fact conditional on several a priori hypotheses: EWAS coverage is sufficient for complex psychiatric problems; Peripheral tissue is … Continue reading Hidden hypotheses of epigenetic studies
This 2018 French review subject was mechanisms of autoimmunity: “Autoimmune diseases (AIDs) encompass more than 80 distinct chronic disorders characterized by inflammatory reactions that can either be systemic or organ specific. In all cases, the disease development is the consequence of the effects of environmental factors in predisposed individuals. Most of the genes identified by … Continue reading Common features of autoimmune diseases
This 2018 US Veterans Administration review subject was resiliency and stress responses: “Neurobiological and behavioral responses to stress are highly variable. Exposure to a similar stressor can lead to heterogeneous outcomes — manifesting psychopathology in one individual, but having minimal effect, or even enhancing resilience, in another. We highlight aspects of stress response modulation related … Continue reading Resiliency in stress responses
This 2018 Hungary/UK study used Bayesian analysis to better understand gene-environment interactions that produce depression: “Most genetic studies do not consider the effect of stressors which may be one reason for the lack of replicable results in candidate gene studies, GWAS [genome-wide association studies] and between human studies and animal models. Animal models of depression … Continue reading A study of gene-environment interactions
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
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
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