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Higgs MJ, Webberley AE, Allan AJ, Talat M, John RM, Isles AR. The parenting hub of the hypothalamus is a focus of imprinted gene action. PLoS Genet 2023; 19:e1010961. [PMID: 37856383 PMCID: PMC10586610 DOI: 10.1371/journal.pgen.1010961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 09/07/2023] [Indexed: 10/21/2023] Open
Abstract
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. Using single-cell RNA sequencing datasets, we identified a specific enrichment of imprinted gene expression in a recognised "parenting hub", the galanin-expressing neurons of the preoptic area. We tested the validity of linking enriched expression in these neurons to function by focusing on MAGE family member L2 (Magel2), an imprinted gene not previously linked to parenting behaviour. We confirmed expression of Magel2 in the preoptic area galanin expressing neurons. We then examined the parenting behaviour of Magel2-null(+/p) mice. Magel2-null mothers, fathers and virgin females demonstrated deficits in pup retrieval, nest building and pup-directed motivation, identifying a central role for this gene in parenting. Finally, we show that Magel2-null mothers and fathers have a significant reduction in POA galanin expressing cells, which in turn contributes to a reduced c-Fos response in the POA upon exposure to pups. Our findings identify a novel imprinted gene that impacts parenting behaviour and, moreover, demonstrates the utility of using single-cell RNA sequencing data to predict gene function from expression and in doing so here, have identified a purposeful role for genomic imprinting in mediating parental behaviour.
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Affiliation(s)
- Matthew J. Higgs
- Behavioural Genetics Group, Centre for Neuropsychiatric, Genetics and Genomics, Neuroscience and Mental Health Innovation Institute, Cardiff University, Cardiff, United Kingdom
| | - Anna E. Webberley
- Behavioural Genetics Group, Centre for Neuropsychiatric, Genetics and Genomics, Neuroscience and Mental Health Innovation Institute, Cardiff University, Cardiff, United Kingdom
| | | | - Moaz Talat
- The Mary Lyon Centre, MRC Harwell, Didcot, United Kingdom
| | - Rosalind M. John
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Anthony R. Isles
- Behavioural Genetics Group, Centre for Neuropsychiatric, Genetics and Genomics, Neuroscience and Mental Health Innovation Institute, Cardiff University, Cardiff, United Kingdom
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Hernandez A, Stohn JP. The Type 3 Deiodinase: Epigenetic Control of Brain Thyroid Hormone Action and Neurological Function. Int J Mol Sci 2018; 19:ijms19061804. [PMID: 29921775 PMCID: PMC6032375 DOI: 10.3390/ijms19061804] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 06/13/2018] [Accepted: 06/15/2018] [Indexed: 12/31/2022] Open
Abstract
Thyroid hormones (THs) influence multiple processes in the developing and adult central nervous system, and their local availability needs to be maintained at levels that are tailored to the requirements of their biological targets. The local complement of TH transporters, deiodinase enzymes, and receptors is critical to ensure specific levels of TH action in neural cells. The type 3 iodothyronine deiodinase (DIO3) inactivates THs and is highly present in the developing and adult brain, where it limits their availability and action. DIO3 deficiency in mice results in a host of neurodevelopmental and behavioral abnormalities, demonstrating the deleterious effects of TH excess, and revealing the critical role of DIO3 in the regulation of TH action in the brain. The fact the Dio3 is an imprinted gene and that its allelic expression pattern varies across brain regions and during development introduces an additional level of control to deliver specific levels of hormone action in the central nervous system (CNS). The sensitive epigenetic nature of the mechanisms controlling the genomic imprinting of Dio3 renders brain TH action particularly susceptible to disruption due to exogenous treatments and environmental exposures, with potential implications for the etiology of human neurodevelopmental disorders.
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Affiliation(s)
- Arturo Hernandez
- Center for Molecular Medicine, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, ME 04074, USA.
- Graduate School for Biomedical Science and Engineering, University of Maine, Orono, ME 04469, USA.
- Department of Medicine, Tufts University School of Medicine, Boston, MA 02111, USA.
| | - J Patrizia Stohn
- Center for Molecular Medicine, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, ME 04074, USA.
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4
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Epigenetics: How Genes and Environment Interact. ENVIRONMENTAL EPIGENOMICS IN HEALTH AND DISEASE 2013. [DOI: 10.1007/978-3-642-23380-7_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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5
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Yang J, Lin S. Likelihood approach for detecting imprinting and in utero maternal effects using general pedigrees from prospective family-based association studies. Biometrics 2011; 68:477-85. [PMID: 22008205 DOI: 10.1111/j.1541-0420.2011.01695.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Genetic imprinting and in utero maternal effects are causes of parent-of-origin effect but they are confounded with each other. Tests attempting to detect only one of these effects would have a severely inflated type I error rate if the assumption of the absence of the other effect is violated. Some existing methods avoid the potential confounding by modeling imprinting and in utero maternal effect simultaneously. However, these methods are not amendable to extended families, which are commonly recruited in family-based studies. In this article, we propose a likelihood approach for detecting imprinting and maternal effects (LIME) using general pedigrees from prospective family-based association studies. LIME formulates the probability of familial genotypes without the Hardy-Weinberg equilibrium assumption by introducing a novel concept called conditional mating type between marry-in founders and their nonfounder spouses. Further, a logit link is used to model the penetrance. To deal with the issue of incomplete pedigree genotypic data, LIME imputes the unobserved genotypes implicitly by considering all compatible ones conditional on the observed genotypes. We carried out a simulation study to evaluate the relative power and type I error of LIME and two existing methods. The results show that the use of extended pedigree data, even with incomplete information, can achieve much greater power than using nuclear families for detecting imprinting and in utero maternal effects without leading to inflated type I error rates.
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Affiliation(s)
- Jingyuan Yang
- Department of Statistics, The Ohio State University, 404 Cockins Hall, 1958 Neil Avenue, Columbus, Ohio 43210, USA.
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Smit H. A conceptual contribution to battles in the brain. BIOLOGY & PHILOSOPHY 2010; 25:803-821. [PMID: 21212823 PMCID: PMC2998249 DOI: 10.1007/s10539-010-9195-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 01/11/2010] [Indexed: 05/30/2023]
Abstract
Badcock and Crespi have advanced the hypothesis that autism and schizophrenia are caused by imbalanced imprinting in the brain. They argue that an imbalance between the effects of paternally and maternally expressed genes on brain development results in either an extreme paternal (autism) or maternal brain (schizophrenia). In this paper their conceptual model is discussed and criticized since it presupposes an incoherent distinction between observable physical and hidden mental phenomena. An alternative model is discussed that may be more fruitful for investigating the possible role of imprinted genes in the development of social behaviour. The development of crying and reactive crying and behaviours necessary for collaborative action are discussed as a promising research area for understanding the effects of imprinted genes.
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Affiliation(s)
- Harry Smit
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
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7
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Abstract
Patterns and risks of human disease have evolved. In this article, I review evidence regarding the importance of recent adaptive evolution, positive selection, and genomic conflicts in shaping the genetic and phenotypic architectures of polygenic human diseases. Strong recent selection in human populations can create and maintain genetically based disease risk primarily through three processes: increased scope for dysregulation from recent human adaptations, divergent optima generated by intraspecific genomic conflicts, and transient or stable deleterious by-products of positive selection caused by antagonistic pleiotropy, ultimately due to trade-offs at the levels of molecular genetics, development, and physiology. Human disease due to these processes appears to be concentrated in three sets of phenotypes: cognition and emotion, reproductive traits, and life-history traits related to long life-span. Diverse, convergent lines of evidence suggest that a small set of tissues whose pleiotropic patterns of gene function and expression are under especially strong selection-brain, placenta, testis, prostate, breast, and ovary-has mediated a considerable proportion of disease risk in modern humans.
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Affiliation(s)
- Bernard J Crespi
- Department of Biosciences, Simon Fraser University, Burnaby, B. C., Canada V5A 1S6.
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8
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Gregg C, Zhang J, Weissbourd B, Luo S, Schroth GP, Haig D, Dulac C. High-resolution analysis of parent-of-origin allelic expression in the mouse brain. Science 2010; 329:643-8. [PMID: 20616232 PMCID: PMC3005244 DOI: 10.1126/science.1190830] [Citation(s) in RCA: 448] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Genomic imprinting results in preferential expression of the paternal or maternal allele of certain genes. We have performed a genome-wide characterization of imprinting in the mouse embryonic and adult brain. This approach uncovered parent-of-origin allelic effects of more than 1300 loci. We identified parental bias in the expression of individual genes and of specific transcript isoforms, with differences between brain regions. Many imprinted genes are expressed in neural systems associated with feeding and motivated behaviors, and parental biases preferentially target genetic pathways governing metabolism and cell adhesion. We observed a preferential maternal contribution to gene expression in the developing brain and a major paternal contribution in the adult brain. Thus, parental expression bias emerges as a major mode of epigenetic regulation in the brain.
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Affiliation(s)
- Christopher Gregg
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
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Renfree MB, Papenfuss AT, Shaw G, Pask AJ. Eggs, embryos and the evolution of imprinting: insights from the platypus genome. Reprod Fertil Dev 2010; 21:935-42. [PMID: 19874717 DOI: 10.1071/rd09092] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Accepted: 08/28/2009] [Indexed: 12/18/2022] Open
Abstract
Genomic imprinting is widespread in eutherian and marsupial mammals. Although there have been many hypotheses to explain why genomic imprinting evolved in mammals, few have examined how it arose. The host defence hypothesis suggests that imprinting evolved from existing mechanisms within the cell that act to silence foreign DNA elements that insert into the genome. However, the changes to the mammalian genome that accompanied the evolution of imprinting have been hard to define due to the absence of large-scale genomic resources from all extant classes. The recent release of the platypus genome sequence has provided the first opportunity to make comparisons between prototherian (monotreme, which show no signs of imprinting) and therian (marsupial and eutherian, which have imprinting) mammals. We compared the distribution of repeat elements known to attract epigenetic silencing across the genome from monotremes and therian mammals, particularly focusing on the orthologous imprinted regions. Our analyses show that the platypus has significantly fewer repeats of certain classes in the regions of the genome that have become imprinted in therian mammals. The accumulation of repeats, especially long-terminal repeats and DNA elements, in therian imprinted genes and gene clusters therefore appears to be coincident with, and may have been a potential driving force in, the development of mammalian genomic imprinting. Comparative platypus genome analyses of orthologous imprinted regions have provided strong support for the host defence hypothesis to explain the origin of imprinting.
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Broad KD, Curley JP, Keverne EB. Increased apoptosis during neonatal brain development underlies the adult behavioral deficits seen in mice lacking a functional paternally expressed gene 3 (Peg3). Dev Neurobiol 2009; 69:314-25. [PMID: 19224563 DOI: 10.1002/dneu.20702] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Inactivation of the maternally imprinted, paternally expressed gene 3 (Peg3) induces deficits in olfactory function, sexual and maternal behaviors, oxytocin neuron number, metabolic homeostasis and growth. Peg3 is expressed in a number of developing hypothalamic and basal forebrain structures and is a component of the P53 apoptosis pathway. Peg3 inactivation in neuronal cell culture lines inhibits P53 mediated apoptosis, which is important in the early postnatal development and sexual differentiation of the brain. In this study, we investigated the effect of inactivating the Peg3 gene on the incidence of caspase 3 positive cells (a marker of apoptosis) in 4- and 6-day postpartum mouse brain. Inactivating the Peg3 gene resulted in an increase in the incidence of total forebrain caspase 3 positive cells at 4 and 6 days postpartum. Increases in specific neuroanatomical regions including the bed nucleus of the stria terminalis, nucleus accumbens, caudate putamen, medial pre-optic area, arcuate nucleus, medial amygdala, anterior cortical and posteriodorsal amygdaloid nuclei, were also observed. In wild-type mice, sex differences in the incidence of caspase 3 positive cells in the medial amygdala, bed nucleus of the stria terminalis, nucleus accumbens, arcuate nucleus and the M2 motor cortex, were also observed. This neural sex difference was ameliorated in the Peg-3 mutant. These findings suggest that the neuronal and behavioral deficits seen in mice lacking a functional Peg3 gene are mediated by increases in the incidence of early neonatal apoptosis in neuroanatomical regions important for reproductive behavior, olfactory and pheromonal processing, thermoregulation and reward.
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Affiliation(s)
- Kevin D Broad
- Sub-Department of Animal Behaviour, University of Cambridge, Madingley, Cambridge, CB3 8AA, United Kingdom.
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11
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Shoji H, Kato K. Maternal care affects the development of maternal behavior in inbred mice. Dev Psychobiol 2009; 51:345-57. [DOI: 10.1002/dev.20375] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Abstract
Genomic imprinting is a widespread epigenetic phenomenon in eutherian mammals, which regulates many aspects of growth and development. Parental conflict over the degree of maternal nutrient transfer is the favoured hypothesis for the evolution of imprinting. Marsupials, like eutherian mammals, are viviparous but deliver an altricial young after a short gestation supported by a fully functional placenta, so can shed light on the evolution and time of acquisition of genomic imprinting. All orthologues of eutherian imprinted genes examined have a conserved expression in the marsupial placenta regardless of their imprint status. Differentially methylated regions (DMRs) are the most common mechanism controlling genomic imprinting in eutherian mammals, but none were found in the marsupial imprinted orthologues of IGF2 receptor (IGF2R), INS or mesoderm-specific transcript (MEST). Instead, histone modification appears to be the mechanism used to silence these genes. At least three genes in marsupials have DMRs: H19, IGF2 and PEG10. PEG10 is particularly interesting as it is derived from a retrotransposon, providing the first direct evidence that retrotransposon insertion can drive the evolution of an imprinted region and of a DMR in mammals. The insertion occurred after the prototherian–therian mammal divergence, suggesting that there may have been strong selection for the retention of imprinted regions that arose during the evolution of placentation. There is currently no evidence for genomic imprinting in the egg-laying monotreme mammals. However, since these mammals do have a short-lived placenta, imprinting appears to be correlated with viviparity but not placentation.
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Affiliation(s)
- Marilyn B Renfree
- Department of Zoology, ARC Centre of Excellence for Kangaroo Genomics, The University of Melbourne, Melbourne, Victoria 3010, Australia.
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13
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Psychosis and autism as diametrical disorders of the social brain. Behav Brain Sci 2008; 31:241-61; discussion 261-320. [DOI: 10.1017/s0140525x08004214] [Citation(s) in RCA: 379] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AbstractAutistic-spectrum conditions and psychotic-spectrum conditions (mainly schizophrenia, bipolar disorder, and major depression) represent two major suites of disorders of human cognition, affect, and behavior that involve altered development and function of the social brain. We describe evidence that a large set of phenotypic traits exhibit diametrically opposite phenotypes in autistic-spectrum versus psychotic-spectrum conditions, with a focus on schizophrenia. This suite of traits is inter-correlated, in that autism involves a general pattern of constrained overgrowth, whereas schizophrenia involves undergrowth. These disorders also exhibit diametric patterns for traits related to social brain development, including aspects of gaze, agency, social cognition, local versus global processing, language, and behavior. Social cognition is thus underdeveloped in autistic-spectrum conditions and hyper-developed on the psychotic spectrum.;>We propose and evaluate a novel hypothesis that may help to explain these diametric phenotypes: that the development of these two sets of conditions is mediated in part by alterations of genomic imprinting. Evidence regarding the genetic, physiological, neurological, and psychological underpinnings of psychotic-spectrum conditions supports the hypothesis that the etiologies of these conditions involve biases towards increased relative effects from imprinted genes with maternal expression, which engender a general pattern of undergrowth. By contrast, autistic-spectrum conditions appear to involve increased relative bias towards effects of paternally expressed genes, which mediate overgrowth. This hypothesis provides a simple yet comprehensive theory, grounded in evolutionary biology and genetics, for understanding the causes and phenotypes of autistic-spectrum and psychotic-spectrum conditions.
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Isles AR, Davies W, Wilkinson LS. Genomic imprinting and the social brain. Philos Trans R Soc Lond B Biol Sci 2006; 361:2229-37. [PMID: 17118935 PMCID: PMC1764840 DOI: 10.1098/rstb.2006.1942] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Genomic imprinting refers to the parent-of-origin-specific epigenetic marking of a number of genes. This epigenetic mark leads to a bias in expression between maternally and paternally inherited imprinted genes, that in some cases results in monoallelic expression from one parental allele. Genomic imprinting is often thought to have evolved as a consequence of the intragenomic conflict between the parental alleles that occurs whenever there is an asymmetry of relatedness. The two main examples of asymmetry of relatedness are when there is partiality of parental investment in offspring (as is the case for placental mammals, where there is also the possibility of extended postnatal care by one parent), and in social groups where there is a sex-biased dispersal. From this evolutionary starting point, it is predicted that, at the behavioural level, imprinted genes will influence what can broadly be termed bonding and social behaviour. We examine the animal and human literature for examples of imprinted genes mediating these behaviours, and divide them into two general classes. Firstly, mother-offspring interactions (suckling, attachment and maternal behaviours) that are predicted to occur when partiality in parental investment in early postnatal offspring occurs; and secondly, adult social interactions, when there is an asymmetry of relatedness in social groups. Finally, we return to the evolutionary theory and examine whether there is a pattern of behavioural functions mediated by imprinted genes emerging from the limited data, and also whether any tangible predictions can be made with regards to the direction of action of genes of maternal or paternal origin.
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Affiliation(s)
- Anthony R Isles
- Laboratory of Cognitive and Behavioural Neuroscience, The Babraham Institute, Babraham Research Campus, Babraham, Cambridge CB2 4AT, UK.
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15
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Badcock C, Crespi B. Imbalanced genomic imprinting in brain development: an evolutionary basis for the aetiology of autism. J Evol Biol 2006; 19:1007-32. [PMID: 16780503 DOI: 10.1111/j.1420-9101.2006.01091.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We describe a new hypothesis for the development of autism, that it is driven by imbalances in brain development involving enhanced effects of paternally expressed imprinted genes, deficits of effects from maternally expressed genes, or both. This hypothesis is supported by: (1) the strong genomic-imprinting component to the genetic and developmental mechanisms of autism, Angelman syndrome, Rett syndrome and Turner syndrome; (2) the core behavioural features of autism, such as self-focused behaviour, altered social interactions and language, and enhanced spatial and mechanistic cognition and abilities, and (3) the degree to which relevant brain functions and structures are altered in autism and related disorders. The imprinted brain theory of autism has important implications for understanding the genetic, epigenetic, neurological and cognitive bases of autism, as ultimately due to imbalances in the outcomes of intragenomic conflict between effects of maternally vs. paternally expressed genes.
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Affiliation(s)
- C Badcock
- Department of Sociology, London School of Economics, London, UK
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16
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Lemaire V, Billard JM, Dutar P, George O, Piazza PV, Epelbaum J, Le Moal M, Mayo W. Motherhood-induced memory improvement persists across lifespan in rats but is abolished by a gestational stress. Eur J Neurosci 2006; 23:3368-74. [PMID: 16820026 DOI: 10.1111/j.1460-9568.2006.04870.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Motherhood modifies the biology and behavior of the female, a process which prepares the mother's cognitive systems that are needed for nurturance. It has recently been shown that motherhood enhances hippocampal-mediated spatial learning and synaptic plasticity. Deleterious and long-term effects of a stress experienced during gestation have been demonstrated on progeny. Surprisingly little is known about the effect of such stress on mothers. Here, we investigated the effect of gestational stress on the adaptive changes due to motherhood. Female rats were mated and stressed during the last week of gestation. Two weeks after weaning, they were submitted to behavioral tests or electrophysiological study. A group of females were then kept for 16 months after motherhood experience to study the long-term effect of gestational stress and motherhood on memory when they were 22 months old. We confirm that a single motherhood experience selectively increases hippocampal-mediated spatial memory during the entire lifespan of female rats and protects them from age-associated memory impairments. However, we demonstrate that a stressful experience during gestation totally abolishes the positive effects of motherhood both on spatial memory and on hippocampal synaptic plasticity (long-term potentiation). Environmental factors that induce biological vulnerability have negative effects even for fundamental biological behaviors.
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Affiliation(s)
- V Lemaire
- University Victor Segalen, INSERM U588 Institut François Magendie, 146 rue Léo Saignat, 33077 Bordeaux Cedex, France.
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17
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Hager R, Johnstone RA. Differential Growth of Own and Alien Pups in Mixed Litters of Mice: A Role for Genomic Imprinting? Ethology 2005. [DOI: 10.1111/j.1439-0310.2005.01097.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Glasgow E, Ryu SL, Yamashita M, Zhang BJ, Mutsuga N, Gainer H. APeg3, a novel paternally expressed gene 3 antisense RNA transcript specifically expressed in vasopressinergic magnocellular neurons in the rat supraoptic nucleus. ACTA ACUST UNITED AC 2005; 137:143-51. [PMID: 15950772 DOI: 10.1016/j.molbrainres.2005.02.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Revised: 02/18/2005] [Accepted: 02/28/2005] [Indexed: 10/25/2022]
Abstract
Vasopressin (VP) and oxytocin (OT) play critical roles in the regulation of salt and water balance, lactation, and various behaviors and are expressed at very high levels in specific magnocellular neurons (MCNs) in the hypothalamo-neurohypophysial system (HNS). In addition to the cell-specific expression of the VP and OT genes in these cells, there are other transcripts that are preferentially expressed in the VP or OT MCNs. One such gene, paternally expressed gene 3 (Peg3), is an imprinted gene expressed exclusively from the paternal allele that encodes a Kruppel-type zinc finger-containing protein involved in maternal behavior and is abundantly expressed in the VP-MCNs. We report here the robust expression in the VP-MCNs of an RNA, which we designate APeg3 that is transcribed in the antisense direction to the 3' untranslated region of the Peg3 gene. The APeg3 mRNA is about 1 kb in size, and the full-length sequence of APeg3, as determined by 5' and 3' RACE, contains an open reading frame that predicts a protein of 93 amino acids and is predominantly expressed in VP-MCNs. Both Peg3 and APeg3 gene expression in the VP-MCNs increase during systemic hyperosmolality in vivo, demonstrating that both of these genes are osmoregulated.
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Affiliation(s)
- Eric Glasgow
- Department of Neurobiology, Northeastern Ohio Universities College of Medicine, Rootstown, OH 44272, USA
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19
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Abstract
When ontogeny takes place in a family, and parents provide essential resources for development, the parents become an environmental component to the development of a wide range of offspring traits. Because differences among parents may partly reflect genetic variation, this environmental component contains genes and may itself evolve. Also, when offspring play an active role in family interactions, offspring become a social environmental component to parents, affecting their behavior in turn, which potentially results in reciprocal social selection. Thus, an evolutionary process of coadaptation to family life, additionally driven by conflicts of interests, may have shaped the expression and development patterns underlying infant behaviors. The complex genetics arising from family interactions can be formalized by extending standard quantitative genetic models. These models demonstrate how the explicit consideration of the family environment can profoundly alter both the expression and evolutionary response to selection of behaviors involved in family interactions. Behavioral genetic studies have begun to unravel the complex genetics underlying infant solicitation behaviors and parental provisioning, although many focus on one side of the interaction. A genetic analysis incorporating interactions among family members explicitly may be critical because the genes underlying the expression of parental provisioning indirectly affect offspring behaviors, and vice versa.
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Affiliation(s)
- Mathias Kölliker
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405-3700, USA.
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Dong C, Li WD, Geller F, Lei L, Li D, Gorlova OY, Hebebrand J, Amos CI, Nicholls RD, Price RA. Possible genomic imprinting of three human obesity-related genetic loci. Am J Hum Genet 2005; 76:427-37. [PMID: 15647995 PMCID: PMC1196395 DOI: 10.1086/428438] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Accepted: 12/28/2004] [Indexed: 11/03/2022] Open
Abstract
To detect potentially imprinted, obesity-related genetic loci, we performed genomewide parent-of-origin linkage analyses under an allele-sharing model for discrete traits and under a family regression model for obesity-related quantitative traits, using a European American sample of 1,297 individuals from 260 families, with 391 microsatellite markers. We also used two smaller, independent samples for replication (a sample of 370 German individuals from 89 families and a sample of 277 African American individuals from 52 families). For discrete-trait analysis, we found evidence for a maternal effect in chromosome region 10p12 across the three samples, with LOD scores of 5.69 (single-point) and 4.52 (multipoint) for the pooled sample. For quantitative-trait analysis, we found the strongest evidence for a maternal effect (single-point LOD of 2.85; multipoint LOD of 4.01 for body mass index [BMI] and 3.69 for waist circumference) in region 12q24 and for a paternal effect (single-point LOD of 4.79; multipoint LOD of 3.72 for BMI) in region 13q32, in the European American sample. The results suggest that parent-of-origin effects, perhaps including genomic imprinting, may play a role in human obesity.
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Affiliation(s)
- Chuanhui Dong
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
| | - Wei-Dong Li
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
| | - Frank Geller
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
| | - Lei Lei
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
| | - Ding Li
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
| | - Olga Y. Gorlova
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
| | - Johannes Hebebrand
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
| | - Christopher I. Amos
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
| | - Robert D. Nicholls
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
| | - R. Arlen Price
- Center for Neurobiology and Behavior, Department of Psychiatry, and Department of Genetics, University of Pennsylvania, Philadelphia; Institute of Medical Biometry and Epidemiology and Clinical Research Group, Department of Child and Adolescent Psychiatry, Philipps-University of Marburg, Marburg, Germany; and Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston
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21
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Davies W, Smith RJ, Kelsey G, Wilkinson LS. Expression patterns of the novel imprinted genes Nap1l5 and Peg13 and their non-imprinted host genes in the adult mouse brain. Gene Expr Patterns 2004; 4:741-7. [PMID: 15465498 DOI: 10.1016/j.modgep.2004.03.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2004] [Revised: 03/19/2004] [Accepted: 03/20/2004] [Indexed: 01/10/2023]
Abstract
Recent work has implicated imprinted gene functioning in neurodevelopment and behaviour and defining the expression patterns of these genes in brain tissue has become a key prerequisite to establishing function. In this work we report on the expression patterns of two novel imprinted loci, Nap1l5 and Peg13, in adult mouse brain using in situ hybridisation methods. Nap1l5 and Peg13 are located, respectively, within the introns of the non-imprinted genes Herc3 and the Tularik1 (T1)/KIAA1882 homologue in two separate microimprinted domains on mouse chromosomes 6 and 15. These 'host' genes are highly expressed in brain and consequently we were interested in assessing their expression patterns in parallel to the imprinted genes. The brain expression of all four genes appeared to be mainly neuronal. The detailed expression profiles of Nap1l5 and Peg13 were generally similar with widespread expression that was relatively high in the septal and hypothalamic regions, the hippocampus and the cerebral cortex. In contrast, there was some degree of dissociation between the imprinted genes and their non-imprinted hosts, in that, whilst there was again widespread expression of Herc3 and the T1/KIAA1882 homologue, these genes were also particularly highly expressed in Purkinje neurons and piriform cortex. We also examined expression of the novel imprinted genes in the adrenal glands. Nap1l5 expression was localised mainly to the adrenal medulla, whilst Peg13 expression was observed more generally throughout the adrenal medulla and the outer cortical layers.
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Affiliation(s)
- William Davies
- Developmental Genetics and Neurobiology Programmes, The Babraham Institute, Babraham, Cambridge CB2 4AT, UK
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22
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Shi W, Lefebvre L, Yu Y, Otto S, Krella A, Orth A, Fundele R. Loss-of-imprinting ofPeg1 in mouse interspecies hybrids is correlated with altered growth. Genesis 2004; 39:65-72. [PMID: 15124229 DOI: 10.1002/gene.20027] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Previous studies have shown that loss-of-imprinting (LOI) is a regular occurrence in interspecies hybrids of the genus Peromyscus. Furthermore, evidence was presented that indicated that LOI is involved in a placental hybrid dysgenesis effect resulting in abnormal placental growth and thus possibly in speciation. We show here that LOI of the strictly paternally expressed gene Peg1 (also called Mest) occurs in F1 hybrids between Mus musculus (MMU) and M. spretus (MSP). Peg1 LOI is correlated with increased body weight and increased weight of two of the organs tested, kidney and spleen. X-gal staining of tissues derived from Peg1(+/-) x MSP F1 mice, carrying a maternal LacZ knock-in allele of Peg1, demonstrates that LOI is stochastic in that it affects different tissues to variable extents and that, even within one tissue, not all cells are similarly affected. Furthermore, this expression from the maternal allele does not necessarily follow the endogenous paternal Peg1 expression pattern. Our results indicate that LOI occurs in interspecies hybrids in the genus Mus and that altered growth is a frequent outcome of LOI.
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Affiliation(s)
- Wei Shi
- Department of Development and Genetics, Evolutionary Biology Center, Uppsala University, Uppsala, Sweden
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23
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Abstract
In contrast to the biallelic expression of most genes, expression of genes subject to genomic imprinting is monoallelic and based on the sex of the transmitting parent. Possession of only a single active allele can lead to deleterious health consequences in humans. Aberrant expression of imprinted genes, through either genetic or epigenetic alterations, can result in developmental failures, neurodevelopmental and neurobehavioral disorders and cancer. The evolutionary emergence of imprinting occurred in a common ancestor to viviparous mammals after divergence from the egg-laying monotremes. Current evidence indicates that imprinting regulation in metatherian mammals differs from that in eutherian mammals. This suggests that imprinting mechanisms are evolving from those that were established 150 million years ago. Therefore, comparing genomic sequence of imprinted domains from marsupials and eutherians with those of orthologous regions in monotremes offers a potentially powerful bioinformatics approach for identifying novel imprinted genes and their regulatory elements. Such comparative studies will also further our understanding of the molecular evolution and phylogenetic distribution of imprinted genes.
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Affiliation(s)
- Susan K Murphy
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
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24
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Hager R, Johnstone RA. The genetic basis of family conflict resolution in mice. Nature 2003; 421:533-5. [PMID: 12556892 DOI: 10.1038/nature01239] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2002] [Accepted: 10/08/2002] [Indexed: 11/09/2022]
Abstract
Asymmetries in the costs and benefits of parental investment for mothers, fathers and offspring result in family conflict over the production and provisioning of young. In species where females provide most resources before and after birth, the resolution of this conflict may be influenced by genes expressed in mothers and by maternally and paternally inherited genes expressed in offspring. Here we disentangle these effects by means of reciprocal mating and cross-fostering of litters between two strains of mice that differ with respect to the typical resolution of family conflict. We find that differences in litter size between these two strains are determined by paternal genotype, whereas differences in provisioning are under maternal control, showing that there is antagonistic coadaptation of maternal and paternal effects on distinct life-history traits. Maternal provisioning is also influenced by the type of foster offspring. Contradictory to theoretical expectations, however, we find no evidence for a negative correlation across strains between maternal provisioning and offspring demand. Instead, we show that there is positive coadaptation such that offspring obtain more resources from foster mothers of the same strain as their natural mother, irrespective of their father's strain.
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Affiliation(s)
- Reinmar Hager
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
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25
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Hofmann HA. Functional genomics of neural and behavioral plasticity. JOURNAL OF NEUROBIOLOGY 2003; 54:272-82. [PMID: 12486709 DOI: 10.1002/neu.10172] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
How does the environment, particularly the social environment, influence brain and behavior and what are the underlying physiologic, molecular, and genetic mechanisms? Adaptations of brain and behavior to changes in the social or physical environment are common in the animal world, either as short-term (i.e., modulatory) or as long-term modifications (e.g., via gene expression changes) in behavioral or physiologic properties. The study of the mechanisms and constraints underlying these dynamic changes requires model systems that offer plastic phenotypes as well as a sufficient level of quantifiable behavioral complexity while being accessible at the physiological and molecular level. In this article, I explore how the new field of functional genomics can contribute to an understanding of the complex relationship between genome and environment that results in highly plastic phenotypes. This approach will lead to the discovery of genes under environmental control and provide the basis for the study of the interrelationship between an individual's gene expression profile and its social phenotype in a given environmental context.
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Affiliation(s)
- Hans A Hofmann
- Harvard University, Bauer Center for Genomics Research, 7 Divinity Ave, Cambridge, Massachusetts 02138, USA.
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26
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Abstract
A hypothetical neurobiological model of Freud's architecture of the mind is presented in an attempt to unify concepts and data derived from molecular biology (e.g., genomic imprinting), systems neuroscience (e.g., neuroanatomochemical circuitries), evolutionary psychology (e.g., human mating strategies), and Freudian psychology. The model posits that events related to genomic imprinting can be regulated in a tissue-specific manner over the course of neural development such that imprinting along the matriline would favor the development of corticostriatal structures whereas imprinting along the patriline would favor the development of limbic-subcortical structures. A neuropsychological analysis of the brain requirements for successful mating presumably would put an evolutionary premium on the corticostriatal system (matrilineal) in men and limbic-subcortical systems (patrilineal) in women. Additionally, the model emphasizes that the ego and the super-ego of Freudian psychology are dependent on corticostriatal mechanisms (matriline-related), while the id is dependent on brainstem processes (patriline-related). It is hoped that the model herein presented has heuristic value for a rapprochement of psychoanalysis and neurobiology.
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Affiliation(s)
- Gilberto N O Brito
- Instituto Fernandes Figueira, FIOCRUZ and Universidade Federal Fluminense, Niterói, RJ, Brazil.
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27
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Abstract
Genomic imprinting in gametogenesis marks a subset of mammalian genes for parent-of-origin-dependent monoallelic expression in the offspring. Embryological and classical genetic experiments in mice that uncovered the existence of genomic imprinting nearly two decades ago produced abnormalities of growth or behavior, without severe developmental malformations. Since then, the identification and manipulation of individual imprinted genes has continued to suggest that the diverse products of these genes are largely devoted to controlling pre- and post-natal growth, as well as brain function and behavior. Here, we review this evidence, and link our discussion to a website (http://www.otago.ac.nz/IGC) containing a comprehensive database of imprinted genes. Ultimately, these data will answer the long-debated question of whether there is a coherent biological rationale for imprinting.
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Affiliation(s)
- Benjamin Tycko
- Institute for Cancer Genetics, Columbia University, New York, New York, USA.
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