Deficiency of the paternally-expressed imprinted gene in mice has sexually dimorphic consequences for offspring communication and social behaviour.

Introduction: Imprinted genes are expressed from one parental allele as a consequence of epigenetic processes initiated in the germline. Consequently, their ability to influence phenotype depends on their parent-of-origin. Recent research suggests that the sex of the individual expressing the imprinted gene is also important.

Better translation via collaboration: The MRC National Mouse Genetics Network.

The MRC National Mouse Genetics Network (NMGN) has been established in the UK to bring together researchers from academia and industry across the country from a wide range of disease areas and research backgrounds to rapidly facilitate clinical translation of mouse research findings and foster an environment of interdisciplinary learning.

The parenting hub of the hypothalamus is a focus of imprinted gene action.

Imprinted genes are subject to germline epigenetic modification resulting in parental-specific allelic silencing. Although genomic imprinting is thought to be important for maternal behaviour, this idea is based on serendipitous findings from a small number of imprinted genes. Here, we undertook an unbiased systems biology approach, taking advantage of the recent delineation of specific neuronal populations responsible for controlling parental care, to test whether imprinted genes significantly converge to regulate parenting behaviour.

Imprinted genes and the manipulation of parenting in mammals.

Genomic imprinting refers to the parent-of-origin expression of genes, which originates from epigenetic events in the mammalian germ line. The evolution of imprinting may reflect a conflict over resource allocation early in life, with silencing of paternal genes in offspring soliciting increased maternal provision and silencing of maternal genes limiting demands on the mother. Parental caregiving has been identified as an area of potential conflict, with several imprinted genes serendipitously found to directly influence the quality of maternal care.

NRSF/REST lies at the intersection between epigenetic regulation, miRNA-mediated gene control and neurodevelopmental pathways associated with Intellectual disability (ID) and Schizophrenia.

Genetic evidence indicates disrupted epigenetic regulation as a major risk factor for psychiatric disorders, but the molecular mechanisms that drive this association remain to be determined. EHMT1 is an epigenetic repressor that is causal for Kleefstra Syndrome (KS), a genetic disorder linked with neurodevelopmental disorders and associated with schizophrenia. Here, we show that reduced EHMT1 activity decreases NRSF/REST protein leading to abnormal neuronal gene expression and progression of neurodevelopment in human iPSC.

Regulation of glutamate transport and neuroinflammation in a term newborn rat model of hypoxic-ischaemic brain injury.

In the newborn brain, moderate-severe hypoxia-ischaemia induces glutamate excitotoxicity and inflammation, possibly via dysregulation of candidate astrocytic glutamate transporter () and pro-inflammatory cytokines (e.g. , , ).

The contribution of imprinted genes to neurodevelopmental and neuropsychiatric disorders.

Imprinted genes are a subset of mammalian genes that are subject to germline parent-specific epigenetic modifications leading monoallelic expression. Imprinted gene expression is particularly prevalent in the brain and it is unsurprising that mutations affecting their expression can lead to neurodevelopmental and/or neuropsychiatric disorders in humans. Here I review the evidence for this, detailing key neurodevelopmental disorders linked to imprinted gene clusters on human chromosomes 15q11-q13 and 14q32, highlighting genes and possible regulatory links between these different syndromes.

Developmental disruption to the cortical transcriptome and synaptosome in a model of SETD1A loss-of-function.

Large-scale genomic studies of schizophrenia implicate genes involved in the epigenetic regulation of transcription by histone methylation and genes encoding components of the synapse. However, the interactions between these pathways in conferring risk to psychiatric illness are unknown. Loss-of-function (LoF) mutations in the gene encoding histone methyltransferase, SETD1A, confer substantial risk to schizophrenia.

Comparison of mouse models reveals a molecular distinction between psychotic illness in PWS and schizophrenia.

Prader-Willi Syndrome (PWS) is a neurodevelopmental disorder caused by mutations affecting paternal chromosome 15q11-q13, and characterized by hypotonia, hyperphagia, impaired cognition, and behavioural problems. Psychotic illness is a challenging problem for individuals with PWS and has different rates of prevalence in distinct PWS genotypes. Previously, we demonstrated behavioural and cognitive endophenotypes of relevance to psychiatric illness in a mouse model for one of the associated PWS genotypes, namely PWS-IC, in which deletion of the imprinting centre leads to loss of paternally imprinted gene expression and over-expression of Ube3a.

Animal models for Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by hyperphagia, hypotonia, learning disability, as well as a range of psychiatric conditions. The conservation of the PWS genetic interval on chromosome 15q11-q13 in human, and a cluster of genes on mouse chromosome 7, has facilitated the use of mice as animal models for PWS. Some models faithfully mimic the loss of all gene expression from the paternally inherited PWS genetic interval, whereas others target smaller regions or individual genes.

Placental endocrine insufficiency programs anxiety, deficits in cognition and atypical social behaviour in offspring.

Abnormally elevated expression of the imprinted PHLDA2 gene has been reported in the placenta of human babies that are growth restricted in utero in several studies. We previously modelled this gene alteration in mice and found that just 2-fold increased expression of Phlda2 resulted in placental endocrine insufficiency. In addition, elevated Phlda2 was found to drive fetal growth restriction (FGR) of transgenic offspring and impaired maternal care by their wildtype mothers.

Lifting the lid on impact and peer review.

has grown in tandem with the British Neuroscience Association's campaign to build Credibility in Neuroscience, which encourages actions and initiatives aimed at improving reproducibility, reliability and openness. This commitment to credibility impacts not only what the Journal publishes, but also how it operates. With that in mind, the Editorial Board sought the views of the neuroscience community on the peer review process, and on how they should respond to the Journal Impact Factor that will be assigned to .

Impairments in sensory-motor gating and information processing in a mouse model of haploinsufficiency.

Regulators of chromatin dynamics and transcription are increasingly implicated in the aetiology of neurodevelopmental disorders. Haploinsufficiency of , encoding a histone methyltransferase, is associated with several neurodevelopmental disorders, including Kleefstra syndrome, developmental delay and autism spectrum disorder. Using a mouse model of haploinsufficiency ( ), we examined a number of brain and behavioural endophenotypes of relevance to neurodevelopmental disorders.

Mice lacking paternal expression of imprinted Grb10 are risk-takers.

The imprinted genes Grb10 and Nesp influence impulsive behavior on a delay discounting task in an opposite manner. A recently developed theory suggests that this pattern of behavior may be representative of predicted effects of imprinted genes on tolerance to risk. Here we examine whether mice lacking paternal expression of Grb10 show abnormal behavior across a number of measures indicative of risk-taking.

Unified Behavioral Scoring for Preclinical Models.

Preclinical mental health research relies upon animal models, and whilst many encouraging advances are being made, reproducibility and translational relevance may be limited by sub-optimal testing or model choices. Animal behaviors are complex and test batteries should be designed to include their multifaceted nature. However, multiple behavioral testing is often avoided due to cost, availability or statistical rigor.

Prader-Willi syndrome imprinting centre deletion mice have impaired baseline and 5-HT2CR-mediated response inhibition.

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by deletion or inactivation of paternally expressed imprinted genes on human chromosome 15q11-q13. In addition to endocrine and developmental issues, PWS presents with behavioural problems including stereotyped behaviour, impulsiveness and cognitive deficits. The PWS genetic interval contains several brain-expressed small nucleolar (sno) RNA species that are subject to genomic imprinting, including snord115 that negatively regulates post-transcriptional modification of the serotonin 2C receptor (5-HT2CR) pre-mRNA potentially leading to a reduction in 5-HT2CR function.

Glutamate Transport and Preterm Brain Injury.

Preterm birth complications are the leading cause of child death worldwide and a top global health priority. Among the survivors, the risk of life-long disabilities is high, including cerebral palsy and impairment of movement, cognition, and behavior. Understanding the molecular mechanisms of preterm brain injuries is at the core of future healthcare improvements.

Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications.

Our willingness to take risks, our ability to wait or the speed with which to make decisions are central features of our personality. However, it is now recognized that impulsive and risk-taking behaviours are not a unitary construct, and different aspects can be both psychologically and neurally dissociated. The range of neurochemicals and brain systems that govern these behaviours is extensive, and this may be a contributing factor to the phenotypic range seen in the human population.

Detailed analysis of paternal knockout Grb10 mice suggests effects on stability of social behavior, rather than social dominance.

Imprinted genes are highly expressed in monoaminergic regions of the midbrain and their functions in this area are thought to have an impact on mammalian social behaviors. One such imprinted gene is Grb10, of which the paternal allele is generally recognized as mediating social dominance behavior. However, there has been no detailed study of social dominance in Grb10 mice.

Genomic Imprinting and Physiological Processes in Mammals.

Complex multicellular organisms, such as mammals, express two complete sets of chromosomes per nucleus, combining the genetic material of both parents. However, epigenetic studies have demonstrated violations to this rule that are necessary for mammalian physiology; the most notable parental allele expression phenomenon is genomic imprinting. With the identification of endogenous imprinted genes, genomic imprinting became well-established as an epigenetic mechanism in which the expression pattern of a parental allele influences phenotypic expression.

Epigenetics, chromatin and brain development and function.

Research investigating epigenetics and chromatin function in brain and behaviour has mushroomed over the last two decades. And yet epigenetics as a biological concept predates the discovery in the 1950s of DNA as the principle mode of inheritance by over a decade. This review explores the past, present and future research into epigenetics as it relates to understanding brain development and function.

Persistence of anxiety symptoms after elective caesarean delivery.

Background: In the UK, 11.8% of expectant mothers undergo an elective caesarean section (ELCS) representing 92 000 births per annum. It is not known to what extent this procedure has an impact on mental well-being in the longer term.

Impulsive Choice in Mice Lacking Paternal Expression of Suggests Intragenomic Conflict in Behavior.

Imprinted genes are expressed from one parental allele only as a consequence of epigenetic events that take place in the mammalian germ line and are thought to have evolved through intragenomic conflict between parental alleles. We demonstrate, for the first time, oppositional effects of imprinted genes on brain and behavior. Specifically, we show that mice lacking paternal make fewer impulsive choices, with no dissociable effects on a separate measure of impulsive action.

Territorial Behavior and Social Stability in the Mouse Require Correct Expression of Imprinted .

Genomic imprinting, the epigenetic process by which transcription occurs from a single parental allele, is believed to influence social behaviors in mammals. An important social behavior is group living, which is enriched in Eutherian mammals relative to monotremes and marsupials. Group living facilitates resource acquisition, defense of territory and co-care of young, but requires a stable social group with complex inter-individual relationships.