Postgenomic Histories

2020 ◽  
pp. 147-176
Author(s):  
Clare Hanson
Keyword(s):  
Gene Expression ◽  
Early Life ◽  
Epigenetic Inheritance ◽  
Social Defeat ◽  
Social Disadvantage ◽  
Literary Texts ◽  
Transgenerational Epigenetic Inheritance ◽  
Darwinian Theory ◽  
Opening Up

Chapter 5 explores literary texts which develop postgenomic perspectives. Margaret Drabble’s novel-memoir The Peppered Moth mobilizes neo-Lamarckian theories to challenge neo-Darwinian views of inheritance. In tracing the experience of social defeat and its impact across generations, it invokes a process close to transgenerational epigenetic inheritance, opening up questions about the biological transmission of social disadvantage. Jackie Kay’s memoir Red Dust Road also pushes against the limits of neo-Darwinian theory, demonstrating that nurture as well as nature can be somatically inscribed, anticipating research in epigenetics which demonstrates that experience can act as a cue for the modification of gene expression. It contrasts the love Kay receives in early life, which builds an enduring resilience, with the experience of racism associated with her brother’s adoption, which generates lasting insecurity. Catherine Malabou’s work on positive and negative plasticity illuminates these divergent trajectories.

scholarly journals Multigenerational Regulation of the Caenorhabditis elegans Chromatin Landscape by Germline Small RNAs

2019 ◽  
Vol 53 (1) ◽  
pp. 289-311 ◽  
Author(s):  
Natasha E. Weiser ◽  
John K. Kim
Keyword(s):  
Gene Expression ◽  
Caenorhabditis Elegans ◽  
Small Rnas ◽  
Model Organism ◽  
Epigenetic Inheritance ◽  
Small Interfering Rnas ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Small Noncoding Rnas ◽  
Rna Pathways

In animals, small noncoding RNAs that are expressed in the germline and transmitted to progeny control gene expression to promote fertility. Germline-expressed small RNAs, including endogenous small interfering RNAs (endo-siRNAs) and Piwi-interacting RNAs (piRNAs), drive the repression of deleterious transcripts such as transposons, repetitive elements, and pseudogenes. Recent studies have highlighted an important role for small RNAs in transgenerational epigenetic inheritance via regulation of heritable chromatin marks; therefore, small RNAs are thought to convey an epigenetic memory of genomic self and nonself elements. Small RNA pathways are highly conserved in metazoans and have been best described for the model organism Caenorhabditis elegans. In this review, we describe the biogenesis, regulation, and function of C. elegans endo-siRNAs and piRNAs, along with recent insights into how these distinct pathways are integrated to collectively regulate germline gene expression, transgenerational epigenetic inheritance, and ultimately, animal fertility.

How do histone modifications contribute to transgenerational epigenetic inheritance in C. elegans?

2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe
Keyword(s):  
Histone Modifications ◽  
Molecular Mechanisms ◽  
Epigenetic Inheritance ◽  
Nematode Caenorhabditis Elegans ◽  
Histone Methyltransferases ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Recent Developments ◽  
Gene Regulatory

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.

scholarly journals Adaptive response to a future life challenge: consequences of early-life environmental complexity in dual-purpose chicks

2020 ◽  
Vol 98 (11) ◽  
Author(s):  
Chao Yan ◽  
Kate Hartcher ◽  
Wen Liu ◽  
Jinlong Xiao ◽  
Hai Xiang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gut Microbiota ◽  
Early Life ◽  
Plasma Corticosterone ◽  
Adaptive Plasticity ◽  
Environmental Complexity ◽  
Dual Purpose ◽  
Stress Related Genes ◽  
Life Challenge ◽  
Environmental Challenge

Abstract Conditions in early life play profound and long-lasting effects on the welfare and adaptability to stress of chickens. This study aimed to explore the hypothesis that the provision of environmental complexity in early life improves birds’ adaptive plasticity and ability to cope with a challenge later in life. It also tried to investigate the effect of the gut-brain axis by measuring behavior, stress hormone, gene expression, and gut microbiota. One-day-old chicks were split into 3 groups: (1) a barren environment (without enrichment items) group (BG, n = 40), (2) a litter materials group (LG, n = 40), and (3) a perches with litter materials group (PLG, n = 40). Then, enrichment items were removed and simulated as an environmental challenge at 31 to 53 d of age. Birds were subjected to a predator test at 42 d of age. In the environmental challenge, when compared with LG, PLG birds were characterized by decreased fearfulness, lower plasma corticosterone, improved gut microbial functions, lower relative mRNA expression of GR, and elevated mRNA expressions of stress-related genes CRH, BDNF, and NR2A in the hypothalamus (all P < 0.05). Unexpectedly, the opposite was true for the LG birds when compared with the BG (P < 0.05). Decreased plasma corticosterone and fearfulness were accompanied by altered hypothalamic gene mRNA expressions of BDNF, NR2A, GR, and CRH through the HPA axis in response to altered gut microbial compositions and functions. The findings suggest that gut microbiota may integrate fearfulness, plasma corticosterone, and gene expression in the hypothalamus to provide an insight into the gut-brain axis in chicks. In conclusion, having access to both perches and litter materials in early life allowed birds to cope better with a future challenge. Birds in perches and litter materials environment may have optimal development and adaptive plasticity through the gut-brain axis.

scholarly journals Maternal Style Selectively Shapes Amygdalar Development and Social Behavior in Rats Genetically Prone to High Anxiety

2015 ◽  
Vol 37 (3) ◽  
pp. 203-214 ◽  
Author(s):  
Joshua L. Cohen ◽  
Matthew E. Glover ◽  
Phyllis C. Pugh ◽  
Andrew D. Fant ◽  
Rebecca K. Simmons ◽  
...  
Keyword(s):  
Gene Expression ◽  
Psychological Health ◽  
Early Life ◽  
Developmental Trajectory ◽  
Emotional Behavior ◽  
Developmental Gene ◽  
Developmental Gene Expression ◽  
Maternal Style ◽  
Anxiety Depression ◽  
Cross Fostering

The early-life environment critically influences neurodevelopment and later psychological health. To elucidate neural and environmental elements that shape emotional behavior, we developed a rat model of individual differences in temperament and environmental reactivity. We selectively bred rats for high versus low behavioral response to novelty and found that high-reactive (bred high-responder, bHR) rats displayed greater risk-taking, impulsivity and aggression relative to low-reactive (bred low-responder, bLR) rats, which showed high levels of anxiety/depression-like behavior and certain stress vulnerability. The bHR/bLR traits are heritable, but prior work revealed bHR/bLR maternal style differences, with bLR dams showing more maternal attention than bHRs. The present study implemented a cross-fostering paradigm to examine the contribution of maternal behavior to the brain development and emotional behavior of bLR offspring. bLR offspring were reared by biological bLR mothers or fostered to a bLR or bHR mother and then evaluated to determine the effects on the following: (1) developmental gene expression in the hippocampus and amygdala and (2) adult anxiety/depression-like behavior. Genome-wide expression profiling showed that cross-fostering bLR rats to bHR mothers shifted developmental gene expression in the amygdala (but not hippocampus), reduced adult anxiety and enhanced social interaction. Our findings illustrate how an early-life manipulation such as cross-fostering changes the brain's developmental trajectory and ultimately impacts adult behavior. Moreover, while earlier studies highlighted hippocampal differences contributing to the bHR/bLR phenotypes, our results point to a role of the amygdala as well. Future work will pursue genetic and cellular mechanisms within the amygdala that contribute to bHR/bLR behavior either at baseline or following environmental manipulations.

scholarly journals Social environment influences the relationship between genotype and gene expression in wild baboons

2013 ◽  
Vol 368 (1618) ◽  
pp. 20120345 ◽  
Author(s):  
Daniel E. Runcie ◽  
Ralph T. Wiedmann ◽  
Elizabeth A. Archie ◽  
Jeanne Altmann ◽  
Gregory A. Wray ◽  
...  
Keyword(s):  
Gene Expression ◽  
Individual Differences ◽  
Social Environment ◽  
Group Size ◽  
Early Life ◽  
Social Connectedness ◽  
Dominance Rank ◽  
Social Stressors ◽  
The Social ◽  
Wild Baboons

Variation in the social environment can have profound effects on survival and reproduction in wild social mammals. However, we know little about the degree to which these effects are influenced by genetic differences among individuals, and conversely, the degree to which social environmental variation mediates genetic reaction norms. To better understand these relationships, we investigated the potential for dominance rank, social connectedness and group size to modify the effects of genetic variation on gene expression in the wild baboons of the Amboseli basin. We found evidence for a number of gene–environment interactions (GEIs) associated with variation in the social environment, encompassing social environments experienced in adulthood as well as persistent effects of early life social environment. Social connectedness, maternal dominance rank and group size all interacted with genotype to influence gene expression in at least one sex, and either in early life or in adulthood. These results suggest that social and behavioural variation, akin to other factors such as age and sex, can impact the genotype–phenotype relationship. We conclude that GEIs mediated by the social environment are important in the evolution and maintenance of individual differences in wild social mammals, including individual differences in responses to social stressors.

scholarly journals Early Life Exposure to Fructose Alters Maternal, Fetal and Neonatal Hepatic Gene Expression and Leads to Sex-Dependent Changes in Lipid Metabolism in Rat Offspring

PLoS ONE ◽  
2015 ◽  
Vol 10 (11) ◽  
pp. e0141962 ◽  
Author(s):  
Zoe E. Clayton ◽  
Mark H. Vickers ◽  
Angelica Bernal ◽  
Cassandra Yap ◽  
Deborah M. Sloboda
Keyword(s):  
Gene Expression ◽  
Lipid Metabolism ◽  
Early Life ◽  
Hepatic Gene Expression ◽  
Rat Offspring ◽  
Early Life Exposure
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