The Experts below are selected from a list of 12867 Experts worldwide ranked by ideXlab platform
David C. Queller - One of the best experts on this subject based on the ideXlab platform.
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theory of Genomic Imprinting conflict in social insects
BMC Evolutionary Biology, 2003Co-Authors: David C. QuellerAbstract:Background Genomic Imprinting refers to the differential expression of genes inherited from the mother and father (matrigenes and patrigenes). The kinship theory of Genomic Imprinting treats parent-specific gene expression as products of within-genome conflict. Specifically, matrigenes and patrigenes will be in conflict over treatment of relatives to which they are differently related. Haplodiploid females have many such relatives, and social insects have many contexts in which they affect relatives, so haplodiploid social insects are prime candidates for tests of the kinship theory of Imprinting.
Daniel Zilberman - One of the best experts on this subject based on the ideXlab platform.
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evolution and function of Genomic Imprinting in plants
Genes & Development, 2015Co-Authors: Jessica A Rodrigues, Daniel ZilbermanAbstract:Genomic Imprinting, an inherently epigenetic phenomenon defined by parent of origin-dependent gene expression, is observed in mammals and flowering plants. Genome-scale surveys of imprinted expression and the underlying differential epigenetic marks have led to the discovery of hundreds of imprinted plant genes and confirmed DNA and histone methylation as key regulators of plant Imprinting. However, the biological roles of the vast majority of imprinted plant genes are unknown, and the evolutionary forces shaping plant Imprinting remain rather opaque. Here, we review the mechanisms of plant Genomic Imprinting and discuss theories of Imprinting evolution and biological significance in light of recent findings.
Shunsuke Suzuki - One of the best experts on this subject based on the ideXlab platform.
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the origin and evolution of Genomic Imprinting and viviparity in mammals
Philosophical Transactions of the Royal Society B, 2013Co-Authors: Marilyn B. Renfree, Shunsuke Suzuki, Tomoko KanekoishinoAbstract:Genomic Imprinting is widespread in eutherian mammals. Marsupial mammals also have Genomic Imprinting, but in fewer loci. It has long been thought that Genomic Imprinting is somehow related to placentation and/or viviparity in mammals, although neither is restricted to mammals. Most imprinted genes are expressed in the placenta. There is no evidence for Genomic Imprinting in the egg-laying monotreme mammals, despite their short-lived placenta that transfers nutrients from mother to embryo. Post natal Genomic Imprinting also occurs, especially in the brain. However, little attention has been paid to the primary source of nutrition in the neonate in all mammals, the mammary gland. Differentially methylated regions (DMRs) play an important role as Imprinting control centres in each imprinted region which usually comprises both paternally and maternally expressed genes (PEGs and MEGs). The DMR is established in the male or female germline (the gDMR). Comprehensive comparative genome studies demonstrated that two imprinted regions, PEG10 and IGF2-H19, are conserved in both marsupials and eutherians and that PEG10 and H19 DMRs emerged in the therian ancestor at least 160 Ma, indicating the ancestral origin of Genomic Imprinting during therian mammal evolution. Importantly, these regions are known to be deeply involved in placental and embryonic growth. It appears that most maternal gDMRs are always associated with Imprinting in eutherian mammals, but emerged at differing times during mammalian evolution. Thus, Genomic Imprinting could evolve from a defence mechanism against transposable elements that depended on DNA methylation established in germ cells.
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retrotransposon silencing by dna methylation can drive mammalian Genomic Imprinting
PLOS Genetics, 2007Co-Authors: Shunsuke Suzuki, Takanori Narita, Andrew J Pask, Changshan Wang, Amber E Alsop, Jennifer Marshall A Graves, Yuji Kohara, Geoffrey Shaw, Takashi Kohda, Fumitoshi IshinoAbstract:Among mammals, only eutherians and marsupials are viviparous and have Genomic Imprinting that leads to parent-of-origin-specific differential gene expression. We used comparative analysis to investigate the origin of Genomic Imprinting in mammals. PEG10 (paternally expressed 10) is a retrotransposon-derived imprinted gene that has an essential role for the formation of the placenta of the mouse. Here, we show that an orthologue of PEG10 exists in another therian mammal, the marsupial tammar wallaby (Macropus eugenii), but not in a prototherian mammal, the egg-laying platypus (Ornithorhynchus anatinus), suggesting its close relationship to the origin of placentation in therian mammals. We have discovered a hitherto missing link of the Imprinting mechanism between eutherians and marsupials because tammar PEG10 is the first example of a differentially methylated region (DMR) associated with Genomic Imprinting in marsupials. Surprisingly, the marsupial DMR was strictly limited to the 5′ region of PEG10, unlike the eutherian DMR, which covers the promoter regions of both PEG10 and the adjacent imprinted gene SGCE. These results not only demonstrate a common origin of the DMR-associated Imprinting mechanism in therian mammals but provide the first demonstration that DMR-associated Genomic Imprinting in eutherians can originate from the repression of exogenous DNA sequences and/or retrotransposons by DNA methylation.
Randy L Jirtle - One of the best experts on this subject based on the ideXlab platform.
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Genomic Imprinting and environmental disease susceptibility.
Environmental Health Perspectives, 2000Co-Authors: Randy L Jirtle, M Sander, J C BarrettAbstract:Genomic Imprinting is one of the most intriguing subtleties of modern genetics. The term "Imprinting" refers to parent-of-origin-dependent gene expression. The presence of imprinted genes can cause cells with a full parental complement of functional autosomal genes to specifically express one allele but not the other, resulting in monoallelic expression of the imprinted loci. Genomic Imprinting plays a critical role in fetal growth and behavioral development, and it is regulated by DNA methylation and chromatin structure. This paper summarizes the Genomic Imprinting and Environmental Disease Susceptibility Conference held 8-10 October 1998 at Duke University, Durham, North Carolina. The conference focused on the importance of Genomic Imprinting in determining susceptibility to environmentally induced diseases. Conference topics included rationales for Imprinting: parental antagonism and speciation; methods for imprinted gene identification: allelic message display and monochromosomal mouse/human hybrids; properties of the imprinted gene cluster human 11p15.5 and mouse distal 7; the epigenetics of X-chromosome inactivation; variability in Imprinting: imprint erasure, non-Mendelian inheritance ratios, and polymorphic Imprinting; Imprinting and behavior: genetics of bipolar disorder, Imprinting in Turner syndrome, and Imprinting in brain development and social behavior; and aberrant methylation: methylation and chromatin structure, methylation and estrogen exposure, methylation of tumor-suppressor genes, and cancer susceptibility. Environmental factors are capable of causing epigenetic changes in DNA that can potentially alter imprint gene expression and that can result in genetic diseases including cancer and behavioral disorders. Understanding the contribution of Imprinting to the regulation of gene expression will be an important step in evaluating environmental influences on human health and disease.
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Genomic Imprinting and cancer
Experimental Cell Research, 1999Co-Authors: Randy L JirtleAbstract:Abstract Although we inherit two copies of all genes, except those that reside on the sex chromosomes, there is a subset of these genes in which only the paternal or maternal copy is functional. This phenomenon of monoallelic, parent-of-origin expression of genes is termed Genomic Imprinting. Imprinted genes are normally involved in embryonic growth and behavioral development, but occasionally they also function inappropriately as oncogenes and tumor suppressor genes. The evidence that imprinted genes play a role in carcinogenesis will be discussed in this review. Additional information about imprinted genes can be found on the Genomic Imprinting Website at: ( http://www.geneimprint.com ).
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Genomic Imprinting implications for human disease
American Journal of Pathology, 1999Co-Authors: Greg J Falls, David J Pulford, Andrew A Wylie, Randy L JirtleAbstract:Genomic Imprinting refers to an epigenetic marking of genes that results in monoallelic expression. This parent-of-origin dependent phenomenon is a notable exception to the laws of Mendelian genetics. Imprinted genes are intricately involved in fetal and behavioral development. Consequently, abnormal expression of these genes results in numerous human genetic disorders including carcinogenesis. This paper reviews Genomic Imprinting and its role in human disease. Additional information about imprinted genes can be found on the Genomic Imprinting Website at http://www.geneimprint.com.
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Polymorphisms, Genomic Imprinting and cancer susceptibility.
Mutation Research-reviews in Mutation Research, 1999Co-Authors: David J Pulford, J.greg Falls, J. Keith Killian, Randy L JirtleAbstract:Polymorphisms have been identified in proto-oncogenes and tumor suppressor genes that predispose people to cancer. Recent evidence indicates that Genomic Imprinting, an epigenetic form of gene regulation that results in uniparental gene expression, can also function as a cancer predisposing event. Thus, cancer susceptibility is increased by both Mendelian inherited genetic and non-Mendelian inherited epigenetic events. Consequently, chemical and physical agents cannot only induce cancer through the formation of genetic mutations but also through epigenetic changes that result in the inappropriate expression of imprinted proto-oncogenes and tumor suppressor genes. The role of Genomic Imprinting in carcinogenesis and cancer susceptibility is examined in this review.
Vett K. Lloyd - One of the best experts on this subject based on the ideXlab platform.
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Genomic Imprinting in Drosophila has properties of both mammalian and insect Imprinting
Development Genes and Evolution, 2008Co-Authors: Matthew Anaka, Audra Lynn, Patrick Mcginn, Vett K. LloydAbstract:Genomic Imprinting is a process that marks DNA, causing a change in gene or chromosome behavior, depending on the sex of the transmitting parent. In mammals, most examples of Genomic Imprinting affect the transcription of individual or small clusters of genes whereas in insects, Genomic Imprinting tends to silence entire chromosomes. This has been interpreted as evidence of independent evolutionary origins for Imprinting. To investigate how these types of Imprinting are related, we performed a phenotypic, molecular, and cytological analysis of an imprinted chromosome in Drosophila melanogaster . Analysis of this chromosome reveals that the imprint results in transcriptional silencing. Yet, the domain of transcriptional silencing is very large, extending at least 1.2 Mb and encompassing over 100 genes, and is associated with decreased somatic polytenization of the entire chromosome. We propose that repression of somatic replication in polytenized cells, as a secondary response to the imprint, acts to extend the size of the imprinted domain to an entire chromosome. Thus, Imprinting in Drosophila has properties of both typical mammalian and insect Imprinting which suggests that Genomic Imprinting in Drosophila and mammals is not fundamentally different; Imprinting is manifest as transcriptional silencing of a few genes or silencing of an entire chromosome depending on secondary processes such as differences in gene density and polytenization.
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Loss of Genomic Imprinting in Drosophila clones.
Genome, 2006Co-Authors: Andrew J. Haigh, Vett K. LloydAbstract:Genomic Imprinting is a process that genetically distinguishes maternal and paternal genomes, and can result in parent-of-origin-dependent monoallelic expression of a gene that is dependent on the parent of origin. As such, an otherwise functional maternally inherited allele may be silenced so that the gene is expressed exclusively from the paternal allele, or vice versa. Once thought to be restricted to mammals, Genomic Imprinting has been documented in angiosperm plants (J.L. Kermicle. 1970. Genetics, 66: 6985), zebrafish (C.C. Martin and R. McGowan. 1995. Genet. Res. 65: 2128), insects, and C. elegans (C.J. Bean, C.E. Schaner, and W.G. Kelly. 2004. Nat. Genet. 36: 100105.). In each case, it appears to rely on differential chromatin structure. Aberrant Imprinting has been implicated in various human cancers and has been detected in a number of cloned mammals, potentially limiting the usefulness of somatic nuclear transfer. Here we show that Genomic Imprinting associated with a mini-X chromosome is lo...
