Project description:Custom Affymetrix SNP used to assay 24 mothers for desired variants. Data processed using the Affymetrix SNP Genotyping Console (Version 4.2, Affymetrix Inc., Santa Clara, CA, USA).
Project description:Adverse experiences in early life are risk factors for the development of behavioral and physiological symptoms that can lead to psychiatric and cognitive disorders later in life. Some of these symptoms can be transmitted to the offspring, in some cases by non-genomic mechanisms involving germ cells. Using a mouse model of unpredictable maternal separation and maternal stress, we show that postnatal trauma alters coping behaviors in adverse conditions in exposed males when adult and in their adult male progeny. The behavioral changes are accompanied by increased glucocorticoid receptor (GR) expression and decreased DNA methylation of the GR promoter in the hippocampus. DNA methylation is also decreased in sperm cells of exposed males when adult. Transgenerational transmission of behavioral symptoms is prevented by paternal environmental enrichment, an effect associated with the reversal of alterations in GR gene expression and DNA methylation in the hippocampus of the male offspring. These findings highlight the influence of both, negative and positive environmental factors on behavior across generations, and the plasticity of the epigenome across life.
Project description:In the study presented here, microRNA expression was profiled in blood samples from mothers of children with autism, with known stress exposure during pregnancy. 2500 mature microRNAs were examined. Thirty-four maternal blood samples were examined in this study. Samples were divided into five groups based on maternal SERT genotypes (LL/LS/SS) and prenatal stress level (High/Low).
Project description:Maternal gene products supplied to the egg during oogenesis drive the earliest events of development in all metazoans. After the initial stages of embryogenesis, maternal transcripts are degraded as zygotic transcription is activated; this is known as the maternal to zygotic transition (MZT). Altering the abundances of maternally deposited factors in the laboratory can have a dramatic effect on development, adult phenotypes and ultimately fitness. Zygotic transcription activation is a tightly regulated process, where the zygotic genome takes over control of development from the maternal genome, and is required for the viability of the organism. Recently, it has been shown that the expression of maternal and zygotic transcripts have evolved in the Drosophila genus over the course of 50 million years of evolution. However, the extent of natural variation of maternal and zygotic transcripts within a species has yet to be determined. We asked how the maternal and zygotic pools of mRNA vary within and between populations of D. melanogaster. In order to maximize sampling of genetic diversity, African lines of D. melanogaster originating from Zambia as well as DGRP lines originating from North America were chosen for transcriptomic analysis. Single embryo RNA-seq was performed before and after zygotic genome activation to determine which transcripts are maternally deposited and which are zygotically expressed within and between these populations. Differential gene expression analysis has been used to quantify quantitative changes in RNA levels within populations as well as fixed expression differences between populations at both stages. Generally, we find that maternal transcripts are more highly conserved, and zygotic transcripts evolve at a higher rate. We find that there is more within-population variation in transcript abundance than between populations and that expression variation is highest post- MZT between African lines. Determining the natural variation of gene expression surrounding the MZT in natural populations of D. melanogaster gives insight into the extent of how a tightly regulated process may vary within a species, the extent of developmental constraint at both stages and on both the maternal and zygotic genomes, and reveals expression changes allowing this species to adapt as it spread across the world.
Project description:Pregnancy is a time of extreme metabolic demand that requires coordinated adaptations between mother and fetus. To determine the contributions of maternal and fetal metabolism to metabolic plasticity during gestation, mice with a liver-specific Carnitine Palmitoyltransferase-2 knockout mice (Cpt2-/-), or Pparα KO mice were subjected to late-gestation nutrient stress, a 24hr fast from E16.5 to E17.5. The fetal response to maternal fasting was dominated by maternal lipid metabolism as the loss of maternal hepatic fatty acid oxidation or Pparα signaling accelerated fetal liver transcriptional programing. These data show that maternal nutritional environment is a major driver of perinatal metabolic programing and plasticity.
Project description:Maternal exposure to social stress during pregnancy is associated with an increased risk of psychiatric disorders in the offspring in later life. How the effects of maternal social stress are transmitted to the developing foetus is unclear. Using a rat model of maternal social stress during pregnancy, we explored the mechanisms by which maternal stress is conveyed to the foetus and the potential for targeted treatment to prevent disease in the offspring. Maternal stress induced oxidative stress in the placenta, but not in the foetal brain, which was prevented by a single administration of nanoparticle-bound antioxidant prior to the stress exposure. Moreover, this antioxidant treatment prevented prenatal stress-induced anxiety-like behaviour in juvenile male offspring, along with neurological and gene expression changes in the offspring brain. In vitro, placental conditioned medium or foetal plasma from stressed pregnancies caused changes to cultured cortical neurons, similar to those observed in the brains of juvenile offspring exposed to prenatal stress, and were found to contain altered levels of extracellular microRNAs but not corticosterone. The present study highlights the crucial role of the placenta, and molecules secreted from the placenta, in foetal brain development and provides evidence of the potential for treatment that can prevent maternal stress-induced foetal programming of neurological disease.
Project description:<p>The Genomic Predictors of Combat Stress Vulnerability and Resilience Study was designed to probe the likely hereditary basis for risk or resilience to develop PTSD and other trauma spectrum disorders. The overall guiding hypothesis was that genomic variation gives rise to risk/susceptibility traits that, when actuated by traumatic environmental stimuli, such as combat, give rise to PTSD and other stress-related phenotypes.</p> <p>Two studies designed to identify risk and resilience factors for combat-induced, stress-related symptoms are being conducted by our group: The Marine Resiliency Study (MRS) is a prospective PTSD study with longitudinal follow-up (pre- and post-exposure to combat stress) of US Marines bound for deployment to Iraq or Afghanistan. Extensive phenotyping includes 3 domains: Psychosocial, Psychophysiologic, and Biophysiologic. The biological and physiological measures collected were chosen in part due to their potential to serve as intermediate phenotypes for stress-related disorders. A second, cross-sectional study involves a cohort of combat-exposed active duty or previously deployed service members (CAVC), including PTSD cases and controls with comparable psychosocial and clinical phenotypes.</p> <p>Little information is available about the factors that explain why some trauma survivors develop stress disorders and some do not. It is hoped that the insights gained from this approach will improve understanding of the genetic contributors to PTSD, and potentially provide novel diagnostic tests and therapeutic approaches to this currently enigmatic and difficult-to-manage condition.</p>