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Sample records for genomic imprinting

  1. Genomic Imprinting in Mammals

    Science.gov (United States)

    Barlow, Denise P.

    2014-01-01

    Genomic imprinting affects a subset of genes in mammals and results in a monoallelic, parental-specific expression pattern. Most of these genes are located in clusters that are regulated through the use of insulators or long noncoding RNAs (lncRNAs). To distinguish the parental alleles, imprinted genes are epigenetically marked in gametes at imprinting control elements through the use of DNA methylation at the very least. Imprinted gene expression is subsequently conferred through lncRNAs, histone modifications, insulators, and higher-order chromatin structure. Such imprints are maintained after fertilization through these mechanisms despite extensive reprogramming of the mammalian genome. Genomic imprinting is an excellent model for understanding mammalian epigenetic regulation. PMID:24492710

  2. Genomic imprinting and Turner syndrome.

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    Bondy, Carolyn A; Hougen, Helen Y; Zhou, Jian; Cheng, Clara M

    2012-05-01

    The term 'genomic imprinting' refers to selective repression of transcription from distinct chromosomal regions determined by their maternal or paternal inheritance. There are two potentially important aspects of imprinting that may manifest in individuals with X monosomy, or Turner syndrome (TS). Given that men are monosomic for Xm while women are mosaic for Xm:Xp, genomic imprinting of important X-linked genes should be associated with sexually dimorphic traits, e.g., social skills, regional fat deposition and adult height. Such X-imprinted traits are predicted to differ in Turner groups monosomic for Xm vs. Xp. We review relevant studies of psychosocial attributes, regional fat distribution and height in TS related to parent of origin for the single normal X chromosome. In addition, we review recent evidence that monosomy for the X chromosome per se, regardless of the parental origin, may disrupt the normal distribution of autosomal imprint patterns. This may contribute to a high rate of fetal loss in human monosomy via impaired placentation in the most severe cases, and to loss of paternal contribution to growth in the mildest manifestation.

  3. [Epigenetics, genomic imprinting and developmental disorders].

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    Le Bouc, Yves; Rossignol, Sylvie; Azzi, Salah; Brioude, Frédéric; Cabrol, Sylvie; Gicquel, Christine; Netchine, Irène

    2010-02-01

    Epigenetic phenomena play a key role in regulating gene expression. One of the most widely studied epigenetic modification is DNA methylation at cytosine residues of CpG dinucleotides in gene promoters, transposons and imprinting control regions (ICR). Genomic imprinting refers to epigenetic marking of genes that results in monoallelic expression depending on the parental origin. Several genes encoding key hormones involved in embryonic and fetal growth are imprinted. There are two critical periods of epigenetic reprogramming: gametogenesis and early preimplantation development. Major reprogramming takes place in primordial germ cells, in which parental imprints are erased and totipotency is restored. Imprint marks are then re-established during spermatogenesis or oogenesis, depending on gender. Upon fertilization, genome-wide demethylation is followed by a wave of de novo methylation, both processes being resisted by imprinted loci. Disruption of imprinting can cause growth defects such as the Beckwith-Wiedemann overgrowth syndrome (BWS) and the Russell-Silver (RSS) intrauterine and postnatal growth retardation syndrome. These growth disorders are caused by abnormal DNA methylation in the 11p15 imprinted region encompassing many imprinted genes, such as IGF2. BWS has been linked to loss of methylation (LOM) in the centromeric ICR2/KCNQIOT1 region of the maternal allele, or gain of methylation in the telomeric ICR1/IGF2/H19 region of the maternal allele. This latter epigenetic defect is associated with an increased risk of tumors such as nephroblastoma. LOM in the telomeric ICR1 region of the paternal allele has been detected in RSS. Early embryogenesis is a critical period of epigenetic regulation, and is sensitive to environmental factors. Individuals conceived with the help of assisted reproductive technology (ART) are over-represented among BWS patients, suggesting that ART may favor altered imprinting at the imprinted centromeric 11p15 locus (LOM in the

  4. Prader-Willi Syndrome: Obesity due to Genomic Imprinting

    National Research Council Canada - National Science Library

    Merlin G. Butler

    2011-01-01

    Prader-Willi syndrome (PWS) is a complex neurodevelopmental disorder due to errors in genomic imprinting with loss of imprinted genes that are paternally expressed from the chromosome 15q11-q13 region. Approximately 70...

  5. Genomic imprinting and the social brain.

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    Isles, Anthony R; Davies, William; Wilkinson, Lawrence S

    2006-12-29

    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.

  6. Evolution and function of genomic imprinting in plants.

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    Rodrigues, Jessica A; Zilberman, Daniel

    2015-12-15

    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. © 2015 Rodrigues and Zilberman; Published by Cold Spring Harbor Laboratory Press.

  7. The landscape of genomic imprinting across diverse adult human tissues

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    Baran, Yael; Subramaniam, Meena; Biton, Anne; Tukiainen, Taru; Tsang, Emily K.; Rivas, Manuel A.; Pirinen, Matti; Gutierrez-Arcelus, Maria; Smith, Kevin S.; Kukurba, Kim R.; Zhang, Rui; Eng, Celeste; Torgerson, Dara G.; Urbanek, Cydney; Li, Jin Billy; Rodriguez-Santana, Jose R.; Burchard, Esteban G.; Seibold, Max A.; MacArthur, Daniel G.; Montgomery, Stephen B.; Zaitlen, Noah A.; Lappalainen, Tuuli

    2015-01-01

    Genomic imprinting is an important regulatory mechanism that silences one of the parental copies of a gene. To systematically characterize this phenomenon, we analyze tissue specificity of imprinting from allelic expression data in 1582 primary tissue samples from 178 individuals from the Genotype-Tissue Expression (GTEx) project. We characterize imprinting in 42 genes, including both novel and previously identified genes. Tissue specificity of imprinting is widespread, and gender-specific effects are revealed in a small number of genes in muscle with stronger imprinting in males. IGF2 shows maternal expression in the brain instead of the canonical paternal expression elsewhere. Imprinting appears to have only a subtle impact on tissue-specific expression levels, with genes lacking a systematic expression difference between tissues with imprinted and biallelic expression. In summary, our systematic characterization of imprinting in adult tissues highlights variation in imprinting between genes, individuals, and tissues. PMID:25953952

  8. The evolutionary foundation of genomic imprinting in lower vertebrates

    Institute of Scientific and Technical Information of China (English)

    XIE BingHua; ZHANG Lei; ZHENG Kang; LUO Chen

    2009-01-01

    In mammals,genomic imprinting confers developmental asymmetry and complementation on the a-rental genomes and makes both parental genomes essential for complete development.Genomic im-printing is,therefore,the first regulatory step of genome-wide gene expression of embryogeneais and thought to be the epigenetic foundation of bisexual reproduction.However,how the genomic imprint-ing is originated,established and maintained during vertebrate evolution remains unknown.Because no endogenous imprinting gene has been identified in non-mammalian vertebrates,genomic imprinting is thought to be a unique evolutionary event of mammals.Here,in order to study the evolutionary origin of genomic imprinting in vertebrates,we examined whether parent-specific methylation occurred in the teleost homologue of mammalian imprinting gene during gametogenesis.Bisulfate sequencing analy-sis showed that,as mammalian Igf2 CpG island,goldfish Igf2 CpG island was a parental differentially methylated region (DMR) that was hypermethylated in sperm but unmethylated in eggs.Unlike mam-malian imprinting gene DMR,however,the parent-specific methylation pattern of goldfish Igf2 DMR was not maintained during embryogenesis,suggesting that the parent-specific methylation of goldfish Igf2 DMR might be a primitive genomic imprinting in the early period of vertebrate evolution.These results indicate that the evolutionary foundation of genomic imprinting exists in lower vertebrates and ge-nomic imprinting should not be considered as a unique evolutionary event of mammals.

  9. [Evolution of genomic imprinting in mammals: what a zoo!].

    Science.gov (United States)

    Proudhon, Charlotte; Bourc'his, Déborah

    2010-05-01

    Genomic imprinting imposes an obligate mode of biparental reproduction in mammals. This phenomenon results from the monoparental expression of a subset of genes. This specific gene regulation mechanism affects viviparous mammals, especially eutherians, but also marsupials to a lesser extent. Oviparous mammals, or monotremes, do not seem to demonstrate monoparental allele expression. This phylogenic confinement suggests that the evolution of the placenta imposed a selective pressure for the emergence of genomic imprinting. This physiological argument is now complemented by recent genomic evidence facilitated by the sequencing of the platypus genome, a rare modern day case of a monotreme. Analysis of the platypus genome in comparison to eutherian genomes shows a chronological and functional coincidence between the appearance of genomic imprinting and transposable element accumulation. The systematic comparative analyses of genomic sequences in different species is essential for the further understanding of genomic imprinting emergence and divergent evolution along mammalian speciation.

  10. Genomic imprinting in mammals: emerging themes and established theories.

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    Andrew J Wood

    2006-11-01

    Full Text Available The epigenetic events that occur during the development of the mammalian embryo are essential for correct gene expression and cell-lineage determination. Imprinted genes are expressed from only one parental allele due to differential epigenetic marks that are established during gametogenesis. Several theories have been proposed to explain the role that genomic imprinting has played over the course of mammalian evolution, but at present it is not clear if a single hypothesis can fully account for the diversity of roles that imprinted genes play. In this review, we discuss efforts to define the extent of imprinting in the mouse genome, and suggest that different imprinted loci may have been wrought by distinct evolutionary forces. We focus on a group of small imprinted domains, which consist of paternally expressed genes embedded within introns of multiexonic transcripts, to discuss the evolution of imprinting at these loci.

  11. Genomic imprinting in development, growth, behavior and stem cells.

    Science.gov (United States)

    Plasschaert, Robert N; Bartolomei, Marisa S

    2014-05-01

    Genes that are subject to genomic imprinting in mammals are preferentially expressed from a single parental allele. This imprinted expression of a small number of genes is crucial for normal development, as these genes often directly regulate fetal growth. Recent work has also demonstrated intricate roles for imprinted genes in the brain, with important consequences on behavior and neuronal function. Finally, new studies have revealed the importance of proper expression of specific imprinted genes in induced pluripotent stem cells and in adult stem cells. As we review here, these findings highlight the complex nature and developmental importance of imprinted genes.

  12. Genomic imprinting and human psychology: cognition, behavior and pathology.

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    Goos, Lisa M; Ragsdale, Gillian

    2008-01-01

    Imprinted genes expressed in the brain are numerous and it has become clear that they play an important role in nervous system development and function. The significant influence of genomic imprinting during development sets the stage for structural and physiological variations affecting psychological function and behaviour, as well as other physiological systems mediating health and well-being. However, our understanding of the role of imprinted genes in behaviour lags far behind our understanding of their roles in perinatal growth and development. Knowledge of genomic imprinting remains limited among behavioral scientists and clinicians and research regarding the influence of imprinted genes on normal cognitive processes and the most common forms of neuropathology has been limited to date. In this chapter, we will explore how knowledge of genomic imprinting can be used to inform our study of normal human cognitive and behavioral processes as well as their disruption. Behavioural analyses of rare imprinted disorders, such as Prader-Willi and Angelman syndromes, provide insight regarding the phenotypic impact of imprinted genes in the brain, and can be used to guide the study of normal behaviour as well as more common but etiologically complex disorders such as ADHD and autism. Furthermore, hypotheses regarding the evolutionary development of imprinted genes can be used to derive predictions about their role in normal behavioural variation, such as that observed in food-related and social interactions.

  13. BACs as tools for the study of genomic imprinting.

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    Tunster, S J; Van De Pette, M; John, R M

    2011-01-01

    Genomic imprinting in mammals results in the expression of genes from only one parental allele. Imprinting occurs as a consequence of epigenetic marks set down either in the father's or the mother's germ line and affects a very specific category of mammalian gene. A greater understanding of this distinctive phenomenon can be gained from studies using large genomic clones, called bacterial artificial chromosomes (BACs). Here, we review the important applications of BACs to imprinting research, covering physical mapping studies and the use of BACs as transgenes in mice to study gene expression patterns, to identify imprinting centres, and to isolate the consequences of altered gene dosage. We also highlight the significant and unique advantages that rapid BAC engineering brings to genomic imprinting research.

  14. BACs as Tools for the Study of Genomic Imprinting

    Directory of Open Access Journals (Sweden)

    S. J. Tunster

    2011-01-01

    Full Text Available Genomic imprinting in mammals results in the expression of genes from only one parental allele. Imprinting occurs as a consequence of epigenetic marks set down either in the father's or the mother's germ line and affects a very specific category of mammalian gene. A greater understanding of this distinctive phenomenon can be gained from studies using large genomic clones, called bacterial artificial chromosomes (BACs. Here, we review the important applications of BACs to imprinting research, covering physical mapping studies and the use of BACs as transgenes in mice to study gene expression patterns, to identify imprinting centres, and to isolate the consequences of altered gene dosage. We also highlight the significant and unique advantages that rapid BAC engineering brings to genomic imprinting research.

  15. Aberrant genomic imprinting in rhesus monkey embryonic stem cells.

    Science.gov (United States)

    Fujimoto, Akihisa; Mitalipov, Shoukhrat M; Kuo, Hung-Chih; Wolf, Don P

    2006-03-01

    Genomic imprinting involves modification of a gene or a chromosomal region that results in the differential expression of parental alleles. Disruption or inappropriate expression of imprinted genes is associated with several clinically significant syndromes and tumorigenesis in humans. Additionally, abnormal imprinting occurs in mouse embryonic stem cells (ESCs) and in clonally derived animals. Imprinted gene expression patterns in primate ESCs are largely unknown, despite the clinical potential of the latter in the cell-based treatment of human disease. Because of the possible implications of abnormal gene expression to cell or tissue replacement therapies involving ESCs, we examined allele specific expression of four imprinted genes in the rhesus macaque. Genomic and complementary DNA from embryos and ESC lines containing useful single nucleotide polymorphisms were subjected to polymerase chain reaction-based amplification and sequence analysis. In blastocysts, NDN expression was variable indicating abnormal or incomplete imprinting whereas IGF2 and SNRPN were expressed exclusively from the paternal allele and H19 from the maternal allele as expected. In ESCs, both NDN and SNRPN were expressed from the paternal allele while IGF2 and H19 showed loss of imprinting and biallelic expression. In differentiated ESC progeny, these expression patterns were maintained. The implications of aberrant imprinted gene expression to ESC differentiation in vitro and on ESC-derived cell function in vivo after transplantation are unknown.

  16. Epigenetic Mechanisms of Genomic Imprinting: Common Themes in the Regulation of Imprinted Regions in Mammals, Plants, and Insects

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    William A. MacDonald

    2012-01-01

    Full Text Available Genomic imprinting is a form of epigenetic inheritance whereby the regulation of a gene or chromosomal region is dependent on the sex of the transmitting parent. During gametogenesis, imprinted regions of DNA are differentially marked in accordance to the sex of the parent, resulting in parent-specific expression. While mice are the primary research model used to study genomic imprinting, imprinted regions have been described in a broad variety of organisms, including other mammals, plants, and insects. Each of these organisms employs multiple, interrelated, epigenetic mechanisms to maintain parent-specific expression. While imprinted genes and imprint control regions are often species and locus-specific, the same suites of epigenetic mechanisms are often used to achieve imprinted expression. This review examines some examples of the epigenetic mechanisms responsible for genomic imprinting in mammals, plants, and insects.

  17. The evolution of genomic imprinting: theories, predictions and empirical tests.

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    Patten, M M; Ross, L; Curley, J P; Queller, D C; Bonduriansky, R; Wolf, J B

    2014-08-01

    The epigenetic phenomenon of genomic imprinting has motivated the development of numerous theories for its evolutionary origins and genomic distribution. In this review, we examine the three theories that have best withstood theoretical and empirical scrutiny. These are: Haig and colleagues' kinship theory; Day and Bonduriansky's sexual antagonism theory; and Wolf and Hager's maternal-offspring coadaptation theory. These theories have fundamentally different perspectives on the adaptive significance of imprinting. The kinship theory views imprinting as a mechanism to change gene dosage, with imprinting evolving because of the differential effect that gene dosage has on the fitness of matrilineal and patrilineal relatives. The sexual antagonism and maternal-offspring coadaptation theories view genomic imprinting as a mechanism to modify the resemblance of an individual to its two parents, with imprinting evolving to increase the probability of expressing the fitter of the two alleles at a locus. In an effort to stimulate further empirical work on the topic, we carefully detail the logic and assumptions of all three theories, clarify the specific predictions of each and suggest tests to discriminate between these alternative theories for why particular genes are imprinted.

  18. Parental genome dosage imbalance deregulates imprinting in Arabidopsis.

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    Pauline E Jullien

    2010-03-01

    Full Text Available In mammals and in plants, parental genome dosage imbalance deregulates embryo growth and might be involved in reproductive isolation between emerging new species. Increased dosage of maternal genomes represses growth while an increased dosage of paternal genomes has the opposite effect. These observations led to the discovery of imprinted genes, which are expressed by a single parental allele. It was further proposed in the frame of the parental conflict theory that parental genome imbalances are directly mirrored by antagonistic regulations of imprinted genes encoding maternal growth inhibitors and paternal growth enhancers. However these hypotheses were never tested directly. Here, we investigated the effect of parental genome imbalance on the expression of Arabidopsis imprinted genes FERTILIZATION INDEPENDENT SEED2 (FIS2 and FLOWERING WAGENINGEN (FWA controlled by DNA methylation, and MEDEA (MEA and PHERES1 (PHE1 controlled by histone methylation. Genome dosage imbalance deregulated the expression of FIS2 and PHE1 in an antagonistic manner. In addition increased dosage of inactive alleles caused a loss of imprinting of FIS2 and MEA. Although FIS2 controls histone methylation, which represses MEA and PHE1 expression, the changes of PHE1 and MEA expression could not be fully accounted for by the corresponding fluctuations of FIS2 expression. Our results show that parental genome dosage imbalance deregulates imprinting using mechanisms, which are independent from known regulators of imprinting. The complexity of the network of regulations between expressed and silenced alleles of imprinted genes activated in response to parental dosage imbalance does not support simple models derived from the parental conflict hypothesis.

  19. Parental genome dosage imbalance deregulates imprinting in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Pauline E Jullien

    2010-03-01

    Full Text Available In mammals and in plants, parental genome dosage imbalance deregulates embryo growth and might be involved in reproductive isolation between emerging new species. Increased dosage of maternal genomes represses growth while an increased dosage of paternal genomes has the opposite effect. These observations led to the discovery of imprinted genes, which are expressed by a single parental allele. It was further proposed in the frame of the parental conflict theory that parental genome imbalances are directly mirrored by antagonistic regulations of imprinted genes encoding maternal growth inhibitors and paternal growth enhancers. However these hypotheses were never tested directly. Here, we investigated the effect of parental genome imbalance on the expression of Arabidopsis imprinted genes FERTILIZATION INDEPENDENT SEED2 (FIS2 and FLOWERING WAGENINGEN (FWA controlled by DNA methylation, and MEDEA (MEA and PHERES1 (PHE1 controlled by histone methylation. Genome dosage imbalance deregulated the expression of FIS2 and PHE1 in an antagonistic manner. In addition increased dosage of inactive alleles caused a loss of imprinting of FIS2 and MEA. Although FIS2 controls histone methylation, which represses MEA and PHE1 expression, the changes of PHE1 and MEA expression could not be fully accounted for by the corresponding fluctuations of FIS2 expression. Our results show that parental genome dosage imbalance deregulates imprinting using mechanisms, which are independent from known regulators of imprinting. The complexity of the network of regulations between expressed and silenced alleles of imprinted genes activated in response to parental dosage imbalance does not support simple models derived from the parental conflict hypothesis.

  20. Gene interactions in the evolution of genomic imprinting.

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    Wolf, J B; Brandvain, Y

    2014-08-01

    Numerous evolutionary theories have been developed to explain the epigenetic phenomenon of genomic imprinting. Here, we explore a subset of theories wherein non-additive genetic interactions can favour imprinting. In the simplest genic interaction--the case of underdominance--imprinting can be favoured to hide effectively low-fitness heterozygous genotypes; however, as there is no asymmetry between maternally and paternally inherited alleles in this model, other means of enforcing monoallelic expression may be more plausible evolutionary outcomes than genomic imprinting. By contrast, more successful interaction models of imprinting rely on an asymmetry between the maternally and paternally inherited alleles at a locus that favours the silencing of one allele as a means of coordinating the expression of high-fitness allelic combinations. For example, with interactions between autosomal loci, imprinting functionally preserves high-fitness genotypes that were favoured by selection in the previous generation. In this scenario, once a focal locus becomes imprinted, selection at interacting loci favours a matching imprint. Uniparental transmission generates similar asymmetries for sex chromosomes and cytoplasmic factors interacting with autosomal loci, with selection favouring the expression of either maternal or paternally derived autosomal alleles depending on the pattern of transmission of the uniparentally inherited factor. In a final class of models, asymmetries arise when genes expressed in offspring interact with genes expressed in one of its parents. Under such a scenario, a locus evolves to have imprinted expression in offspring to coordinate the interaction with its parent's genome. We illustrate these models and explore key links and differences using a unified framework.

  1. THE MEANING OF GENOMIC IMPRINTING IN HUMAN GENETIC AND DEFECTOLOGY

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    Anastas LAKOSKI

    2000-12-01

    Full Text Available Several genetic phenomena do not appear to conform the Mendel's low in the sense that they are not inherited in simple way through the generations. Such exceptions to Mendel's laws include new mutations, changes in chromosomes, expanded triplet sequences, and genomic imprinting. Many genetic diseases involve spontaneous mutations that are not inherited from generation to generation. Changes in chromosomes include nondisjunction, which is the most important cause of mental retardation, the trisomy of Dowen syndrome. Expanded triplet repeats are responsible for the next important cause of mental retardation, fragile X, and for Huntington's disease. Genomic imprinting occurs when the expression of a gene depends on whether it is inherited from the mother or from the father. In this paper the phenomenon of genomic imprinting is explained on the occurrence of Angelman and Prader-Willi syndromes. It's essential for the counselor to be able during the genetic counseling to recognize this phenomenon and to make a proper decision.

  2. Does genomic imprinting play a role in autoimmunity?

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    Camprubí, Cristina; Monk, David

    2011-01-01

    In the 19th century Gregor Mendel defined the laws of genetic inheritance by crossing different types of peas. From these results arose his principle of equivalence: the gene will have the same behaviour whether it is inherited from the mother or the father. Today, several key exceptions to this principle are known, for example sex-linked traits and genes in the mitochondrial genome, whose inheritance patterns are referred to as 'non mendelian'. A third, important exception in mammals is that of genomic imprinting, where transcripts are expressed in a monoallelic fashion from only the maternal or the paternal chromosome. In this chapter, we discuss how parent-of-origin effects and genomic imprinting may play a role in autoimmunity and speculate how imprinted miRNAs may influence the expression of many target autoimmune associated genes.

  3. Bisphenol a exposure disrupts genomic imprinting in the mouse.

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    Martha Susiarjo

    2013-04-01

    Full Text Available Exposure to endocrine disruptors is associated with developmental defects. One compound of concern, to which humans are widely exposed, is bisphenol A (BPA. In model organisms, BPA exposure is linked to metabolic disorders, infertility, cancer, and behavior anomalies. Recently, BPA exposure has been linked to DNA methylation changes, indicating that epigenetic mechanisms may be relevant. We investigated effects of exposure on genomic imprinting in the mouse as imprinted genes are regulated by differential DNA methylation and aberrant imprinting disrupts fetal, placental, and postnatal development. Through allele-specific and quantitative real-time PCR analysis, we demonstrated that maternal BPA exposure during late stages of oocyte development and early stages of embryonic development significantly disrupted imprinted gene expression in embryonic day (E 9.5 and 12.5 embryos and placentas. The affected genes included Snrpn, Ube3a, Igf2, Kcnq1ot1, Cdkn1c, and Ascl2; mutations and aberrant regulation of these genes are associated with imprinting disorders in humans. Furthermore, the majority of affected genes were expressed abnormally in the placenta. DNA methylation studies showed that BPA exposure significantly altered the methylation levels of differentially methylated regions (DMRs including the Snrpn imprinting control region (ICR and Igf2 DMR1. Moreover, exposure significantly reduced genome-wide methylation levels in the placenta, but not the embryo. Histological and immunohistochemical examinations revealed that these epigenetic defects were associated with abnormal placental development. In contrast to this early exposure paradigm, exposure outside of the epigenetic reprogramming window did not cause significant imprinting perturbations. Our data suggest that early exposure to common environmental compounds has the potential to disrupt fetal and postnatal health through epigenetic changes in the embryo and abnormal development of the

  4. Non-conflict theories for the evolution of genomic imprinting.

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    Spencer, H G; Clark, A G

    2014-08-01

    Theories focused on kinship and the genetic conflict it induces are widely considered to be the primary explanations for the evolution of genomic imprinting. However, there have appeared many competing ideas that do not involve kinship/conflict. These ideas are often overlooked because kinship/conflict is entrenched in the literature, especially outside evolutionary biology. Here we provide a critical overview of these non-conflict theories, providing an accessible perspective into this literature. We suggest that some of these alternative hypotheses may, in fact, provide tenable explanations of the evolution of imprinting for at least some loci.

  5. Genomic imprinting and the evolutionary psychology of human kinship.

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    Haig, David

    2011-06-28

    Genomic imprinting is predicted to influence behaviors that affect individuals to whom an actor has different degrees of matrilineal and patrilineal kinship (asymmetric kin). Effects of imprinted genes are not predicted in interactions with nonrelatives or with individuals who are equally related to the actor's maternally and paternally derived genes (unless a gene also has pleiotropic effects on fitness of asymmetric kin). Long-term mating bonds are common in most human populations, but dissolution of marriage has always affected a significant proportion of mated pairs. Children born in a new union are asymmetric kin of children born in a previous union. Therefore, the innate dispositions of children toward parents and sibs are expected to be sensitive to cues of marital stability, and these dispositions may be subject to effects of imprinted genes.

  6. Non-coding RNAs and the acquisition of genomic imprinting in mammals

    Institute of Scientific and Technical Information of China (English)

    ZHANG YiJun; QU LiangHu

    2009-01-01

    Genomic imprinting, representing parent-specific expression of alleles at a locus, Is mainly evident in flowering plants and placental mammals. Most imprinted genes, including numerous non-coding RNAs, are located in clusters regulated by imprinting control regions (ICRs). The acquisition and evolution of genomic imprinting is among the most fundamental genetic questions. Discoveries about the transition of mammalian imprinted gene domains from their non-imprinted ancestors, especially recent studies undertaken on the most ancient mammalian clades - the marsupials and monotremes from which model species genomes have recently been sequenced, are of high value. By reviewing and analyzing these studies, a close connection between non-coding RNAs and the acquisition of genomic imprinting in mammals is demonstrated. The evidence comes from two observations accompanied with the ac-quisition of the imprinting: (i) many novel non-coding RNA genes emerged in imprinted regions; (ii) the expressions of some conserved non-coding RNAs have changed dramatically. Furthermore, a system-atical analysis of imprinted snoRNA (small nucleolar RNA) genes from 15 vertebrates suggests that the origination of imprinted snoRNAs occurred after the divergence between eutherians and marsupials, followed by a rapid expansion leading to the fixation of major gene families in the eutherian ancestor prior to the radiation of modern placental mammals. Involved in the regulation of imprinted silencing and mediating the ohromatins epigenetic modification may be the major roles that non-coding RNAs play during the acquisition of genomic imprinting in mammals.

  7. Influence Exogenous Factors on Genomic Imprinting. 1. Effect of Nutrition and Provision of Micronutrients in Mother on Genomic Imprinting Descendants

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    A.Ye. Abaturov

    2016-10-01

    Full Text Available The article analyzes the impact of maternal nutrition during pregnancy on the forming of genomic imprinting in the fetus. It was shown that changes in DNA methylation of imprinted genes, induced by infringement of providing protein and micronutrients, are accompanied by abnormalities of phy­sical development and increased risk of chronic inflammatory diseases, diseases of the cardiovascular system, the metabolic syndrome in the child’s postnatal life. It is emphasized that in order to prevent the development of imprinting-associated di­sease in a child special attention should be paid to the adequate content of protein, folic acid, methionine and group B vitamins in diet of pregnant women while forming their diet.

  8. THE MEANING OF GENOMIC IMPRINTING IN HUMAN GENETIC AND DEFECTOLOGY

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    Anastas LAKOSKI

    2000-01-01

    Several genetic phenomena do not appear to conform the Mendel's low in the sense that they are not inherited in simple way through the generations. Such exceptions to Mendel's laws include new mutations, changes in chromosomes, expanded triplet sequences, and genomic imprinting. Many genetic diseases involve spontaneous mutations that are not inherited from generation to generation. Changes in chromosomes include nondisjunction, which is the most important cause of mental retardation, the tri...

  9. Genome-wide analysis reveals a complex pattern of genomic imprinting in mice.

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    Jason B Wolf

    2008-06-01

    Full Text Available Parent-of-origin-dependent gene expression resulting from genomic imprinting plays an important role in modulating complex traits ranging from developmental processes to cognitive abilities and associated disorders. However, while gene-targeting techniques have allowed for the identification of imprinted loci, very little is known about the contribution of imprinting to quantitative variation in complex traits. Most studies, furthermore, assume a simple pattern of imprinting, resulting in either paternal or maternal gene expression; yet, more complex patterns of effects also exist. As a result, the distribution and number of different imprinting patterns across the genome remain largely unexplored. We address these unresolved issues using a genome-wide scan for imprinted quantitative trait loci (iQTL affecting body weight and growth in mice using a novel three-generation design. We identified ten iQTL that display much more complex and diverse effect patterns than previously assumed, including four loci with effects similar to the callipyge mutation found in sheep. Three loci display a new phenotypic pattern that we refer to as bipolar dominance, where the two heterozygotes are different from each other while the two homozygotes are identical to each other. Our study furthermore detected a paternally expressed iQTL on Chromosome 7 in a region containing a known imprinting cluster with many paternally expressed genes. Surprisingly, the effects of the iQTL were mostly restricted to traits expressed after weaning. Our results imply that the quantitative effects of an imprinted allele at a locus depend both on its parent of origin and the allele it is paired with. Our findings also show that the imprinting pattern of a locus can be variable over ontogenetic time and, in contrast to current views, may often be stronger at later stages in life.

  10. The Drosophila homolog of the mammalian imprint regulator, CTCF, maintains the maternal genomic imprint in Drosophila melanogaster

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    Rasheva Vanya

    2010-07-01

    Full Text Available Abstract Background CTCF is a versatile zinc finger DNA-binding protein that functions as a highly conserved epigenetic transcriptional regulator. CTCF is known to act as a chromosomal insulator, bind promoter regions, and facilitate long-range chromatin interactions. In mammals, CTCF is active in the regulatory regions of some genes that exhibit genomic imprinting, acting as insulator on only one parental allele to facilitate parent-specific expression. In Drosophila, CTCF acts as a chromatin insulator and is thought to be actively involved in the global organization of the genome. Results To determine whether CTCF regulates imprinting in Drosophila, we generated CTCF mutant alleles and assayed gene expression from the imprinted Dp(1;fLJ9 mini-X chromosome in the presence of reduced CTCF expression. We observed disruption of the maternal imprint when CTCF levels were reduced, but no effect was observed on the paternal imprint. The effect was restricted to maintenance of the imprint and was specific for the Dp(1;fLJ9 mini-X chromosome. Conclusions CTCF in Drosophila functions in maintaining parent-specific expression from an imprinted domain as it does in mammals. We propose that Drosophila CTCF maintains an insulator boundary on the maternal X chromosome, shielding genes from the imprint-induced silencing that occurs on the paternally inherited X chromosome. See commentary: http://www.biomedcentral.com/1741-7007/8/104

  11. Short interspersed transposable elements (SINEs) are excluded from imprinted regions in the human genome.

    Science.gov (United States)

    Greally, John M

    2002-01-08

    To test whether regions undergoing genomic imprinting have unique genomic characteristics, imprinted and nonimprinted human loci were compared for nucleotide and retroelement composition. Maternally and paternally expressed subgroups of imprinted genes were found to differ in terms of guanine and cytosine, CpG, and retroelement content, indicating a segregation into distinct genomic compartments. Imprinted regions have been normally permissive to L1 long interspersed transposable element retroposition during mammalian evolution but universally and significantly lack short interspersed transposable elements (SINEs). The primate-specific Alu SINEs, as well as the more ancient mammalian-wide interspersed repeat SINEs, are found at significantly low densities in imprinted regions. The latter paleogenomic signature indicates that the sequence characteristics of currently imprinted regions existed before the mammalian radiation. Transitions from imprinted to nonimprinted genomic regions in cis are characterized by a sharp inflection in SINE content, demonstrating that this genomic characteristic can help predict the presence and extent of regions undergoing imprinting. During primate evolution, SINE accumulation in imprinted regions occurred at a decreased rate compared with control loci. The constraint on SINE accumulation in imprinted regions may be mediated by an active selection process. This selection could be because of SINEs attracting and spreading methylation, as has been found at other loci. Methylation-induced silencing could lead to deleterious consequences at imprinted loci, where inactivation of one allele is already established, and expression is often essential for embryonic growth and survival.

  12. Genomic imprinting is variably lost during reprogramming of mouse iPS cells

    OpenAIRE

    2013-01-01

    Derivation of induced pluripotent stem (iPS) cells is mainly an epigenetic reprogramming process. It is still quite controversial how genomic imprinting is reprogrammed in iPS cells. Thus, we derived multiple iPS clones from genetically identical mouse somatic cells. We found that parentally inherited imprint was variably lost among these iPS clones. Concurrent with the loss of DNA methylation imprint at the corresponding Snrpn and Peg3 imprinted regions, parental origin-specific expression o...

  13. Absence of genomic imprinting at the DiGeorge locus

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    Theophile, D.; Berube, D.; Auge, J.; Vekemans, M. [Hopital Necker-Enfants Malades, Paris (France)

    1994-09-01

    In situ hybridization with fluorescence probes (FISH) on interphase nuclei allows evaluation of the stage of DNA replication. For example, in a diploid cell in G1, unreplicated DNA gives two single dots of hybridization whereas in a diploid cell in G2, for loci which have already replicated, the hybridization signal is seen as two pairs of doublets. In contrast, sequences which have an asynchronous replication are characterized by one double hybridization signal and one single hybridization signal. It has been shown recently that sequences subject to genomic imprinting have an asynchronous replication, i.e., the two homologous alleles have a different pattern of replication. We have tested the replication pattern of different sequences of the DiGeorge critical region using FISH. The results obtained with probes 48F8, C350, C237 and COS40 show no evidence of asynchronous replication. This suggests that these loci are not subject to imprinting. These results are in agreement with recent observation of cases of uniparental disomy of chromosome 22 without phenotypic features. Further studies are necessary to exclude other regions of chromosome 22 which might be subject to genomic imprinting.

  14. Genomic imprinting is variably lost during reprogramming of mouse iPS cells.

    Science.gov (United States)

    Takikawa, Sachiko; Ray, Chelsea; Wang, Xin; Shamis, Yulia; Wu, Tien-Yuan; Li, Xiajun

    2013-09-01

    Derivation of induced pluripotent stem (iPS) cells is mainly an epigenetic reprogramming process. It is still quite controversial how genomic imprinting is reprogrammed in iPS cells. Thus, we derived multiple iPS clones from genetically identical mouse somatic cells. We found that parentally inherited imprint was variably lost among these iPS clones. Concurrent with the loss of DNA methylation imprint at the corresponding Snrpn and Peg3 imprinted regions, parental origin-specific expression of the Snrpn and Zim1 imprinted genes was also lost in these iPS clones. This loss of parental genomic imprinting in iPS cells was likely caused by the reprogramming process during iPS cell derivation because extended culture of iPS cells did not lead to significant increase in the loss of genomic imprinting. Intriguingly, one to several paternal chromosomes appeared to have acquired de novo methylation at the Snrpn and Zac1 imprinted regions in a high percentage of iPS clones. These results might have some implications for future therapeutic applications of iPS cells. Since DNA methylation imprint can be completely erased in some iPS clones at multiple imprinted regions, iPS cell reprogramming may also be employed to dissect the underlying mechanisms of erasure, reacquisition and maintenance of genomic imprinting in mammals.

  15. Genomic Imprinting and the Expression of Affect in Angelman Syndrome: What's in the Smile?

    Science.gov (United States)

    Oliver, Chris; Horsler, Kate; Berg, Katy; Bellamy, Gail; Dick, Katie; Griffiths, Emily

    2007-01-01

    Background: Kinship theory (or the genomic conflict hypothesis) proposes that the phenotypic effects of genomic imprinting arise from conflict between paternally and maternally inherited alleles. A prediction arising for social behaviour from this theory is that imbalance in this conflict resulting from a deletion of a maternally imprinted gene,…

  16. Genomic Imprinting and the Expression of Affect in Angelman Syndrome: What's in the Smile?

    Science.gov (United States)

    Oliver, Chris; Horsler, Kate; Berg, Katy; Bellamy, Gail; Dick, Katie; Griffiths, Emily

    2007-01-01

    Background: Kinship theory (or the genomic conflict hypothesis) proposes that the phenotypic effects of genomic imprinting arise from conflict between paternally and maternally inherited alleles. A prediction arising for social behaviour from this theory is that imbalance in this conflict resulting from a deletion of a maternally imprinted gene,…

  17. Non-coding RNAs and the acquisition of genomic imprinting in mammals

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Genomic imprinting,representing parent-specific expression of alleles at a locus,is mainly evident in flowering plants and placental mammals.Most imprinted genes,including numerous non-coding RNAs,are located in clusters regulated by imprinting control regions(ICRs).The acquisition and evolution of genomic imprinting is among the most fundamental genetic questions.Discoveries about the transition of mammalian imprinted gene domains from their non-imprinted ancestors,especially recent studies undertaken on the most ancient mammalian clades-the marsupials and monotremes from which model species genomes have recently been sequenced,are of high value.By reviewing and analyzing these studies,a close connection between non-coding RNAs and the acquisition of genomic imprinting in mammals is demonstrated.The evidence comes from two observations accompanied with the acquisition of the imprinting:(i) many novel non-coding RNA genes emerged in imprinted regions;(ii) the expressions of some conserved non-coding RNAs have changed dramatically.Furthermore,a systematical analysis of imprinted snoRNA(small nucleolar RNA) genes from 15 vertebrates suggests that the origination of imprinted snoRNAs occurred after the divergence between eutherians and marsupials,followed by a rapid expansion leading to the fixation of major gene families in the eutherian ancestor prior to the radiation of modern placental mammals.Involved in the regulation of imprinted silencing and mediating the chromatins epigenetic modification may be the major roles that non-coding RNAs play during the acquisition of genomic imprinting in mammals.

  18. Genomic Imprinting Is Implicated in the Psychology of Music.

    Science.gov (United States)

    Mehr, Samuel A; Kotler, Jennifer; Howard, Rhea M; Haig, David; Krasnow, Max M

    2017-08-01

    Why do people sing to babies? Human infants are relatively altricial and need their parents' attention to survive. Infant-directed song may constitute a signal of that attention. In Prader-Willi syndrome (PWS), a rare disorder of genomic imprinting, genes from chromosome 15q11-q13 that are typically paternally expressed are unexpressed, which results in exaggeration of traits that reduce offspring's investment demands on the mother. PWS may thus be associated with a distinctive musical phenotype. We report unusual responses to music in people with PWS. Subjects with PWS ( N = 39) moved more during music listening, exhibited greater reductions in heart rate in response to music listening, and displayed a specific deficit in pitch-discrimination ability relative to typically developing adults and children ( N = 589). Paternally expressed genes from 15q11-q13, which are unexpressed in PWS, may thus increase demands for music and enhance perceptual sensitivity to music. These results implicate genomic imprinting in the psychology of music, informing theories of music's evolutionary history.

  19. Genomic imprinting and maternal effect genes in haplodiploid sex determination.

    Science.gov (United States)

    van de Zande, L; Verhulst, E C

    2014-01-01

    The research into the Drosophila melanogaster sex-determining system has been at the basis of all further research on insect sex determination. This further research has made it clear that, for most insect species, the presence of sufficient functional Transformer (TRA) protein in the early embryonic stage is essential for female sexual development. In Hymenoptera, functional analysis of sex determination by knockdown studies of sex-determining genes has only been performed for 2 species. The first is the social insect species Apis mellifera, the honeybee, which has single-locus complementary sex determination (CSD). The other species is the parasitoid Nasonia vitripennis, the jewel wasp. Nasonia has a non-CSD sex-determining system, described as the maternal effect genomic imprinting sex determination system (MEGISD). Here, we describe the arguments that eventually led to the formulation of MEGISD and the experimental data that supported and refined this model. We evaluate the possibility that DNA methylation lies at the basis of MEGISD and briefly address the role of genomic imprinting in non-CSD sex determination in other Hymenoptera.

  20. Convergent and divergent evolution of genomic imprinting in the marsupial Monodelphis domestica

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    Das Radhika

    2012-08-01

    Full Text Available Abstract Background Genomic imprinting is an epigenetic phenomenon resulting in parent-of-origin specific monoallelic gene expression. It is postulated to have evolved in placental mammals to modulate intrauterine resource allocation to the offspring. In this study, we determined the imprint status of metatherian orthologues of eutherian imprinted genes. Results L3MBTL and HTR2A were shown to be imprinted in Monodelphis domestica (the gray short-tailed opossum. MEST expressed a monoallelic and a biallelic transcript, as in eutherians. In contrast, IMPACT, COPG2, and PLAGL1 were not imprinted in the opossum. Differentially methylated regions (DMRs involved in regulating imprinting in eutherians were not found at any of the new imprinted loci in the opossum. Interestingly, a novel DMR was identified in intron 11 of the imprinted IGF2R gene, but this was not conserved in eutherians. The promoter regions of the imprinted genes in the opossum were enriched for the activating histone modification H3 Lysine 4 dimethylation. Conclusions The phenomenon of genomic imprinting is conserved in Therians, but the marked difference in the number and location of imprinted genes and DMRs between metatherians and eutherians indicates that imprinting is not fully conserved between the two Therian infra-classes. The identification of a novel DMR at a non-conserved location as well as the first demonstration of histone modifications at imprinted loci in the opossum suggest that genomic imprinting may have evolved in a common ancestor of these two Therian infra-classes with subsequent divergence of regulatory mechanisms in the two lineages.

  1. Stability of XIST repression in relation to genomic imprinting following global genome demethylation in a human cell line

    OpenAIRE

    E.S.S. de Araújo; Vasques, L.R.; Stabellini,R.; A.C.V. Krepischi; Pereira, L.V.

    2014-01-01

    DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting thatXIST repression is due to a more stable epigenetic mar...

  2. Genomic imprinting in the Arabidopsis embryo is partly regulated by PRC2.

    Science.gov (United States)

    Raissig, Michael T; Bemer, Marian; Baroux, Célia; Grossniklaus, Ueli

    2013-01-01

    Genomic imprinting results in monoallelic gene expression in a parent-of-origin-dependent manner and is regulated by the differential epigenetic marking of the parental alleles. In plants, genomic imprinting has been primarily described for genes expressed in the endosperm, a tissue nourishing the developing embryo that does not contribute to the next generation. In Arabidopsis, the genes MEDEA (MEA) and PHERES1 (PHE1), which are imprinted in the endosperm, are also expressed in the embryo; whether their embryonic expression is regulated by imprinting or not, however, remains controversial. In contrast, the maternally expressed in embryo 1 (mee1) gene of maize is clearly imprinted in the embryo. We identified several imprinted candidate genes in an allele-specific transcriptome of hybrid Arabidopsis embryos and confirmed parent-of-origin-dependent, monoallelic expression for eleven maternally expressed genes (MEGs) and one paternally expressed gene (PEG) in the embryo, using allele-specific expression analyses and reporter gene assays. Genetic studies indicate that the Polycomb Repressive Complex 2 (PRC2) but not the DNA METHYLTRANSFERASE1 (MET1) is involved in regulating imprinted expression in the embryo. In the seedling, all embryonic MEGs and the PEG are expressed from both parents, suggesting that the imprint is erased during late embryogenesis or early vegetative development. Our finding that several genes are regulated by genomic imprinting in the Arabidopsis embryo clearly demonstrates that this epigenetic phenomenon is not a unique feature of the endosperm in both monocots and dicots.

  3. Genomic imprinting in the Arabidopsis embryo is partly regulated by PRC2.

    Directory of Open Access Journals (Sweden)

    Michael T Raissig

    Full Text Available Genomic imprinting results in monoallelic gene expression in a parent-of-origin-dependent manner and is regulated by the differential epigenetic marking of the parental alleles. In plants, genomic imprinting has been primarily described for genes expressed in the endosperm, a tissue nourishing the developing embryo that does not contribute to the next generation. In Arabidopsis, the genes MEDEA (MEA and PHERES1 (PHE1, which are imprinted in the endosperm, are also expressed in the embryo; whether their embryonic expression is regulated by imprinting or not, however, remains controversial. In contrast, the maternally expressed in embryo 1 (mee1 gene of maize is clearly imprinted in the embryo. We identified several imprinted candidate genes in an allele-specific transcriptome of hybrid Arabidopsis embryos and confirmed parent-of-origin-dependent, monoallelic expression for eleven maternally expressed genes (MEGs and one paternally expressed gene (PEG in the embryo, using allele-specific expression analyses and reporter gene assays. Genetic studies indicate that the Polycomb Repressive Complex 2 (PRC2 but not the DNA METHYLTRANSFERASE1 (MET1 is involved in regulating imprinted expression in the embryo. In the seedling, all embryonic MEGs and the PEG are expressed from both parents, suggesting that the imprint is erased during late embryogenesis or early vegetative development. Our finding that several genes are regulated by genomic imprinting in the Arabidopsis embryo clearly demonstrates that this epigenetic phenomenon is not a unique feature of the endosperm in both monocots and dicots.

  4. Genomic imprinting in the development and evolution of psychotic spectrum conditions.

    Science.gov (United States)

    Crespi, Bernard

    2008-11-01

    I review and evaluate genetic and genomic evidence salient to the hypothesis that the development and evolution of psychotic spectrum conditions have been mediated in part by alterations of imprinted genes expressed in the brain. Evidence from the genetics and genomics of schizophrenia, bipolar disorder, major depression, Prader-Willi syndrome, Klinefelter syndrome, and other neurogenetic conditions support the hypothesis that the etiologies of psychotic spectrum conditions commonly involve genetic and epigenetic imbalances in the effects of imprinted genes, with a bias towards increased relative effects from imprinted genes with maternal expression or other genes favouring maternal interests. By contrast, autistic spectrum conditions, including Kanner autism, Asperger syndrome, Rett syndrome, Turner syndrome, Angelman syndrome, and Beckwith-Wiedemann syndrome, commonly engender increased relative effects from paternally expressed imprinted genes, or reduced effects from genes favouring maternal interests. Imprinted-gene effects on the etiologies of autistic and psychotic spectrum conditions parallel the diametric effects of imprinted genes in placental and foetal development, in that psychotic spectrum conditions tend to be associated with undergrowth and relatively-slow brain development, whereas some autistic spectrum conditions involve brain and body overgrowth, especially in foetal development and early childhood. An important role for imprinted genes in the etiologies of psychotic and autistic spectrum conditions is consistent with neurodevelopmental models of these disorders, and with predictions from the conflict theory of genomic imprinting.

  5. Maternal control of nutrient allocation in plant seeds by genomic imprinting.

    Science.gov (United States)

    Costa, Liliana M; Yuan, Jing; Rouster, Jacques; Paul, Wyatt; Dickinson, Hugh; Gutierrez-Marcos, Jose F

    2012-01-24

    Imprinted genes are commonly expressed in mammalian placentas and in plant seed endosperms, where they exhibit preferential uniparental allelic expression. In mammals, imprinted genes directly regulate placental function and nutrient distribution from mother to fetus; however, none of the >60 imprinted genes thus far reported in plants have been demonstrated to play an equivalent role in regulating the flow of resources to the embryo. Here we show that imprinted Maternally expressed gene1 (Meg1) in maize is both necessary and sufficient for the establishment and differentiation of the endosperm nutrient transfer cells located at the mother:seed interface. Consistent with these findings, Meg1 also regulates maternal nutrient uptake, sucrose partitioning, and seed biomass yield. In addition, we generated an imprinted and nonimprinted synthetic Meg1 ((syn)Meg1) dosage series whereby increased dosage and absence of imprinting both resulted in an unequal investment of maternal resources into the endosperm. These findings highlight dosage regulation by genomic imprinting as being critical for maintaining a balanced distribution of maternal nutrients to filial tissues in plants, as in mammals. However, unlike in mammals, Meg1 is a maternally expressed imprinted gene that surprisingly acts to promote rather than restrict nutrient allocation to the offspring.

  6. Stability of XIST repression in relation to genomic imprinting following global genome demethylation in a human cell line

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, E.S.S. de [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Centro Internacional de Pesquisa, A.C. Camargo Cancer Center, São Paulo, SP (Brazil); Vasques, L.R. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Stabellini, R.; Krepischi, A.C.V. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Centro Internacional de Pesquisa, A.C. Camargo Cancer Center, São Paulo, SP (Brazil); Pereira, L.V. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-10-17

    DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting that XIST repression is due to a more stable epigenetic mark than imprinting. To test this hypothesis, we induced acute hypomethylation in HCT116 cells by 5-aza-2′-deoxycytidine (5-aza-CdR) treatment (HCT116-5-aza-CdR) and compared that to DKO cells, evaluating DNA methylation by microarray and monitoring the expression of XIST and imprinted genes IGF2, H19, and PEG10. Whereas imprinted genes showed biallelic expression in HCT116-5-aza-CdR and DKO cells, the XIST locus was hypomethylated and weakly expressed only under acute hypomethylation conditions, indicating the importance of XIST repression in the active X to cell survival. Given that DNMT3A is the only active DNMT in DKO cells, it may be responsible for ensuring the repression of XIST in those cells. Taken together, our data suggest that XIST repression is more tightly controlled than genomic imprinting and, at least in part, is due to DNMT3A.

  7. A maternal-offspring coadaptation theory for the evolution of genomic imprinting.

    Directory of Open Access Journals (Sweden)

    Jason B Wolf

    2006-11-01

    Full Text Available Imprinted genes are expressed either from the maternally or paternally inherited copy only, and they play a key role in regulating complex biological processes, including offspring development and mother-offspring interactions. There are several competing theories attempting to explain the evolutionary origin of this monoallelic pattern of gene expression, but a prevailing view has emerged that holds that genomic imprinting is a consequence of conflict between maternal and paternal gene copies over maternal investment. However, many imprinting patterns and the apparent overabundance of maternally expressed genes remain unexplained and may be incompatible with current theory. Here we demonstrate that sole expression of maternal gene copies is favored by natural selection because it increases the adaptive integration of offspring and maternal genomes, leading to higher offspring fitness. This novel coadaptation theory for the evolution of genomic imprinting is consistent with results of recent studies on epigenetic effects, and it provides a testable hypothesis for the origin of previously unexplained major imprinting patterns across different taxa. In conjunction with existing hypotheses, our results suggest that imprinting may have evolved due to different selective pressures at different loci.

  8. imprints

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    Mindi Rhoades

    2016-07-01

    Full Text Available This set of poems emerges from the flashpoint at the intersection of art, text, translation, and meaning-making. Several result directly from a class field trip with art educator Terry Barrett’s to the Columbus Museum of Art. We wrote during prolonged interactions with particular pieces. Others result from reflecting on making and remembering. The title of this collection, “imprint,” operates on multiple levels. There is the imprint of the text itself, the prints of the photos, the fictional prints and printmaking referenced, the mental images burned into memory, the lasting impression. There is something magical about trying to translate evanescent ideas, unformed understandings, and ephemeral moments into something more, something lasting, something to keep. These poems represent an attempt to capture something fleeting and slippery also in words. They are an attempt to pause, to contemplate in slower cadence, to ponder the surfeit of signs. They are an attempt to notice, to echo, to share and spark connections. They are an assemblage of images told in fractured pieces, bundled together, and shared.

  9. Differential differences in methylation status of putative imprinted genes among cloned swine genomes.

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    Chih-Jie Shen

    Full Text Available DNA methylation is a major epigenetic modification in the mammalian genome that regulates crucial aspects of gene function. Mammalian cloning by somatic cell nuclear transfer (SCNT often results in gestational or neonatal failure with only a small proportion of manipulated embryos producing live births. Many of the embryos that survive to term later succumb to a variety of abnormalities that are likely due to inappropriate epigenetic reprogramming. Aberrant methylation patterns of imprinted genes in cloned cattle and mice have been elucidated, but few reports have analyzed the cloned pig genome. Four surviving cloned sows that were created by ear fibroblast nuclear transfer, each with a different life span and multiple organ defects, such as heart defects and bone growth delay, were used as epigenetic study materials. First, we identified four putative differential methylation regions (DMR of imprinted genes in the wild-type pig genome, including two maternally imprinted loci (INS and IGF2 and two paternally imprinted loci (H19 and IGF2R. Aberrant DNA methylation, either hypermethylation or hypomethylation, commonly appeared in H19 (45% of imprinted loci hypermethylated vs. 30% hypomethylated, IGF2 (40% vs. 0%, INS (50% vs. 5%, and IGF2R (15% vs. 45% in multiple tissues from these four cloned sows compared with wild-type pigs. Our data suggest that aberrant epigenetic modifications occur frequently in the genome of cloned swine. Even with successful production of cloned swine that avoid prenatal or postnatal death, the perturbation of methylation in imprinted genes still exists, which may be one of reason for their adult pathologies and short life. Understanding the aberrant pattern of gene imprinting would permit improvements in future cloning techniques.

  10. Genomic imprinting in primate embryos and embryonic stem cells.

    Science.gov (United States)

    Mitalipov, Shoukhrat M

    2006-01-01

    Embryonic stem (ES) cells hold promise for cell and tissue replacement approaches to treating human diseases. However, long-term in vitro culture and manipulations of ES cells may adversely affect their epigenetic integrity including imprinting. Disruption or inappropriate expression of imprinted genes is associated with several clinically significant syndromes and tumorigenesis in humans. We demonstrated aberrant biallelic expression of IGF2 and H19 in several rhesus monkey ES cell lines while SNRPN and NDN were normally imprinted and expressed from the paternal allele. In contrast, expanded blastocyst-stage embryos, from which these ES cells were derived, exhibited normal paternal expression of IGF2 and maternal expression of H19. To test the possibility that aberrant methylation at an imprinting centre (IC) upstream of H19 accounts for the relaxed imprinting of IGF2 and H19, we performed comprehensive methylation analysis by investigating methylation profiles of CpG sites within the IGF2/H19 IC. Our results demonstrate abnormal hypermethylation within the IGF2/H19 IC in all analysed ES cell lines consistent with biallelic expression of these genes. Cellular overproliferation and tumour formation resulting from tissue or cell transplantation are potential problems that must be addressed before clinical trials of ES cell-based therapy are initiated.

  11. Genomic imprinting in plants: what makes the functions of paternal and maternal genes different in endosperm formation?

    Science.gov (United States)

    Ohnishi, Takayuki; Sekine, Daisuke; Kinoshita, Tetsu

    2014-01-01

    Genomic imprinting refers to the unequal expression of maternal and paternal alleles according to the parent of origin. This phenomenon is regulated by epigenetic controls and has been reported in placental mammals and flowering plants. Although conserved characteristics can be identified across a wide variety of taxa, it is believed that genomic imprinting evolved independently in animal and plant lineages. Plant genomic imprinting occurs most obviously in the endosperm, a terminally differentiated embryo-nourishing tissue that is required for seed development. Recent studies have demonstrated a close relationship between genomic imprinting and the development of elaborate defense mechanisms against parasitic elements during plant sexual reproduction. In this chapter, we provide an introductory description of genomic imprinting in plants, and focus on recent advances in our understanding of its role in endosperm development, the frontline of maternal and paternal epigenomes.

  12. Applications of the site-specific recombinase Cre to the study of genomic imprinting.

    Science.gov (United States)

    Oh-McGinnis, Rosemary; Jones, Meaghan J; Lefebvre, Louis

    2010-07-01

    The development of gene targeting approaches has had a tremendous impact on the functional analysis of the mouse genome. A specific application of this technique has been the adaptation of the bacteriophage P1 Cre/loxP site-specific recombinase system which allows for the precise recombination between two loxP sites, resulting in deletion or inversion of the intervening sequences. Because of the efficiency of this system, it can be applied to conditional deletions of relatively short coding sequences or regulatory elements but also to more extensive chromosomal rearrangement strategies. Both mechanistic and functional studies of genomic imprinting have benefited from the development of the Cre/loxP technology. Since imprinted genes within large chromosomal regions are regulated by the action of cis-acting sequences known as imprinting centers, chromosomal engineering approaches are particularly well suited to the elucidation of long-range mechanisms controlling the imprinting of autosomal genes. Here we review the applications of the Cre/loxP technology to the study of genomic imprinting, highlight important insights gained from these studies and discuss future directions in the field.

  13. Development of a monkey model for the study of primate genomic imprinting.

    Science.gov (United States)

    Fujimoto, A; Mitalipov, S M; Clepper, L L; Wolf, D P

    2005-06-01

    An understanding of the role of imprinted genes in primate development requires the identification of suitable genetic markers that allow analysis of allele-specific expression and methylation status. Four genes, NDN (Necdin), H19, SNRPN and IGF2, known to be imprinted in mice and humans, were selected for study in rhesus monkeys along with two imprinting centres (ICs) associated with the regulation of H19/IGF2, NDN and SNRPN. GAPD was employed as a non-imprinted control gene. Primers designed to amplify polymorphic regions in these genes and ICs were based on human sequences. Genomic DNA was isolated from peripheral blood leukocytes of 93 rhesus macaques of Indian or Chinese-origin. Sequence analysis of amplicons resulted in the identification of 32 unique SNPs. Country-of-origin related differences in SNP distributions were evident. Since disruptions in imprinted gene expression and associated developmental abnormalities may result from in vitro embryo manipulation, we also examined imprinting in NDN, H19, SNRPN and IGF2 in rhesus monkey infants produced by natural mating or by ICSI. Muscle biopsies followed by RT-PCR and sequence analysis were performed in four heterozygous animals produced by natural mating and all four genes were expressed monoallelically supporting the conclusion that these genes are normally imprinted in monkeys. In the case of ICSI, five informative infants were selected based on parental analysis. Allele-specific studies indicated that the expected uniparental expression patterns were retained in animals produced from manipulated embryos. Moreover, methylation analysis revealed that CpG islands within H19/IGF2 and SNURF/SNRPN ICs were differentially methylated. The approach described here will allow examination of imprinting in the embryos and embryonic stem cells of the monkey.

  14. A statistical design for testing transgenerational genomic imprinting in natural human populations.

    Directory of Open Access Journals (Sweden)

    Yao Li

    Full Text Available Genomic imprinting is a phenomenon in which the same allele is expressed differently, depending on its parental origin. Such a phenomenon, also called the parent-of-origin effect, has been recognized to play a pivotal role in embryological development and pathogenesis in many species. Here we propose a statistical design for detecting imprinted loci that control quantitative traits based on a random set of three-generation families from a natural population in humans. This design provides a pathway for characterizing the effects of imprinted genes on a complex trait or disease at different generations and testing transgenerational changes of imprinted effects. The design is integrated with population and cytogenetic principles of gene segregation and transmission from a previous generation to next. The implementation of the EM algorithm within the design framework leads to the estimation of genetic parameters that define imprinted effects. A simulation study is used to investigate the statistical properties of the model and validate its utilization. This new design, coupled with increasingly used genome-wide association studies, should have an immediate implication for studying the genetic architecture of complex traits in humans.

  15. A statistical design for testing transgenerational genomic imprinting in natural human populations.

    Science.gov (United States)

    Li, Yao; Guo, Yunqian; Wang, Jianxin; Hou, Wei; Chang, Myron N; Liao, Duanping; Wu, Rongling

    2011-02-25

    Genomic imprinting is a phenomenon in which the same allele is expressed differently, depending on its parental origin. Such a phenomenon, also called the parent-of-origin effect, has been recognized to play a pivotal role in embryological development and pathogenesis in many species. Here we propose a statistical design for detecting imprinted loci that control quantitative traits based on a random set of three-generation families from a natural population in humans. This design provides a pathway for characterizing the effects of imprinted genes on a complex trait or disease at different generations and testing transgenerational changes of imprinted effects. The design is integrated with population and cytogenetic principles of gene segregation and transmission from a previous generation to next. The implementation of the EM algorithm within the design framework leads to the estimation of genetic parameters that define imprinted effects. A simulation study is used to investigate the statistical properties of the model and validate its utilization. This new design, coupled with increasingly used genome-wide association studies, should have an immediate implication for studying the genetic architecture of complex traits in humans.

  16. Influence of Exogenous Factors on Genomic Imprinting. 2. Effect of Bad Habits of Parents on Genomic Imprinting of the Descendants

    Directory of Open Access Journals (Sweden)

    A.E. Abaturov

    2016-11-01

    Full Text Available The article presents research data, which suggest that alcohol abuse and smoking of parents have an adverse effect on fetal development and the health of the child. These factors disrupt the processes of DNA methylation of imprinted genes, causing an increased risk of intrauterine growth retardation, and of pathological abnormalities in fetal neurogenesis.

  17. The conflict theory of genomic imprinting: how much can be explained?

    Science.gov (United States)

    Iwasa, Y

    1998-01-01

    In some mammalian genes, paternally and maternally derived alleles are expressed differently: this phenomenon is called genomic imprinting. Several-explanations have been proposed for the observed patterns of genomic imprinting, but the most successful explanation is the genetic conflict hypothesis--natural selection operating on the gene expression produces the parental origin-dependent gene expression--because the paternally derived allele tends to be less related to the siblings of the same mother than the maternal allele and hence the paternal allele should evolve to be more aggressive in obtaining maternal resources. The successes and failures of this argument have been examined in explaining the observed patterns of genomic imprinting in mammals. After a brief summary of the observations with some examples, a quantitative genetic model describing the evolution of the cis-regulating element of a gene affecting the maternal resource acquisition was presented. The model supports the verbal argument that the growth enhancer should evolve to show imprinting with the paternal allele expressed and the maternal allele inactive, whereas a growth suppressor gene tends to have an inactive paternal allele and an active maternal allele. There are four major problems of the genetic conflict hypothesis. (1) Some genes affect embryonic growth but are not imprinted (e.g., Igf1), which can be explained by considering recessive, deleterious mutations on the coding regions, (2) A gene exists that shows the pattern that is a perfect reversal (Mash2), which is needed for placental growth, and yet has an active maternal allele and an inactive paternal allele. This can be explained if the overproduction of this gene causes dose-sensitive abortion to occur in early gestation. (3) Paternal disomies are sometimes smaller than normal embryos. This is a likely outcome of evolution if imprinted genes control the allocation between placenta and embryo by modifying the cell developmental

  18. Mammalian-specific genomic functions: Newly acquired traits generated by genomic imprinting and LTR retrotransposon-derived genes in mammals

    Science.gov (United States)

    KANEKO-ISHINO, Tomoko; ISHINO, Fumitoshi

    2015-01-01

    Mammals, including human beings, have evolved a unique viviparous reproductive system and a highly developed central nervous system. How did these unique characteristics emerge in mammalian evolution, and what kinds of changes did occur in the mammalian genomes as evolution proceeded? A key conceptual term in approaching these issues is “mammalian-specific genomic functions”, a concept covering both mammalian-specific epigenetics and genetics. Genomic imprinting and LTR retrotransposon-derived genes are reviewed as the representative, mammalian-specific genomic functions that are essential not only for the current mammalian developmental system, but also mammalian evolution itself. First, the essential roles of genomic imprinting in mammalian development, especially related to viviparous reproduction via placental function, as well as the emergence of genomic imprinting in mammalian evolution, are discussed. Second, we introduce the novel concept of “mammalian-specific traits generated by mammalian-specific genes from LTR retrotransposons”, based on the finding that LTR retrotransposons served as a critical driving force in the mammalian evolution via generating mammalian-specific genes. PMID:26666304

  19. Abnormal expression of DNA methyltransferases and genomic imprinting in cloned goat fibroblasts.

    Science.gov (United States)

    Wan, Yongjie; Deng, Mingtian; Zhang, Guomin; Ren, Caifang; Zhang, Hao; Zhang, Yanli; Wang, Lizhong; Wang, Feng

    2016-01-01

    Somatic cell nuclear transfer (SCNT) is a useful way to produce cloned animals. However, SCNT animals exhibit DNA methylation and genomic imprinting abnormalities. These abnormalities may be due to the faulty epigenetic reprogramming of donor cells. To investigate the consequence of SCNT on the genomic imprinting and global methylation in the donor cells, growth patterns and apoptosis of cloned goat fibroblast cells (CGFCs) at passage 7 were determined. Growth patterns in CGFCs were similar to the controls; however, the growth rate in log phase was lower and apoptosis in CGFCs were significantly higher (P < 0.01). In addition, quantitative expression analysis of three DNA methyltransferases (Dnmt) and two imprinted genes (H19, IGF2R) was conducted in CGFCs: Dnmt1 and Dnmt3b expression was significantly reduced (P < 0.01), and H19 expression was decreased sixfold (P < 0.01); however, the expression of Dnmt3a was unaltered and IGF2R expression was significantly increased (P < 0.05). Finally, we used bisulfite sequencing PCR to compare the DNA methylation patterns in differentially methylated regions (DMRs) of H19 and IGF2R. The DMRs of H19 (P < 0.01) and IGF2R (P < 0.01) were both highly methylated in CGFCs. These results indicate that the global genome might be hypomethylated. Moreover, there is an aberrant expression of imprinted genes and DMR methylation in CGFCs.

  20. Next-Generation Sequencing Techniques Reveal that Genomic Imprinting Is Absent in Day-Old Gallus gallus domesticus Brains.

    Science.gov (United States)

    Wang, Qiong; Li, Kaiyang; Zhang, Daixi; Li, Junying; Xu, Guiyun; Zheng, Jiangxia; Yang, Ning; Qu, Lujiang

    2015-01-01

    Genomic imprinting is a phenomenon characterized by parent-of-origin-specific gene expression. While widely documented in viviparous mammals and plants, imprinting in oviparous birds remains controversial. Because genomic imprinting is temporal- and tissue-specific, we investigated this phenomenon only in the brain tissues of 1-day-old chickens (Gallus gallus). We used next-generation sequencing technology to compare four transcriptomes pooled from 11 chickens, generated from reciprocally crossed families, to the DNA sequences of their parents. Candidate imprinted genes were then selected from these sequence alignments and subjected to verification experiments that excluded all but one SNP. Subsequent experiments performed with two new sets of reciprocally crossed families resulted in the exclusion of that candidate SNP as well. Attempts to find evidence of genomic imprinting from long non-coding RNAs yielded negative results. We therefore conclude that genomic imprinting is absent in the brains of 1-day-old chickens. However, due to the temporal and tissue specificity of imprinting, our results cannot be extended to all growth stages and tissue types.

  1. The genome of a Mongolian individual reveals the genetic imprints of Mongolians on modern human populations.

    Science.gov (United States)

    Bai, Haihua; Guo, Xiaosen; Zhang, Dong; Narisu, Narisu; Bu, Junjie; Jirimutu, Jirimutu; Liang, Fan; Zhao, Xiang; Xing, Yanping; Wang, Dingzhu; Li, Tongda; Zhang, Yanru; Guan, Baozhu; Yang, Xukui; Yang, Zili; Shuangshan, Shuangshan; Su, Zhe; Wu, Huiguang; Li, Wenjing; Chen, Ming; Zhu, Shilin; Bayinnamula, Bayinnamula; Chang, Yuqi; Gao, Ying; Lan, Tianming; Suyalatu, Suyalatu; Huang, Hui; Su, Yan; Chen, Yujie; Li, Wenqi; Yang, Xu; Feng, Qiang; Wang, Jian; Yang, Huanming; Wang, Jun; Wu, Qizhu; Yin, Ye; Zhou, Huanmin

    2014-11-05

    Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]-1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians.

  2. A systems-level approach to parental genomic imprinting: the imprinted gene network includes extracellular matrix genes and regulates cell cycle exit and differentiation.

    Science.gov (United States)

    Al Adhami, Hala; Evano, Brendan; Le Digarcher, Anne; Gueydan, Charlotte; Dubois, Emeric; Parrinello, Hugues; Dantec, Christelle; Bouschet, Tristan; Varrault, Annie; Journot, Laurent

    2015-03-01

    Genomic imprinting is an epigenetic mechanism that restrains the expression of ∼ 100 eutherian genes in a parent-of-origin-specific manner. The reason for this selective targeting of genes with seemingly disparate molecular functions is unclear. In the present work, we show that imprinted genes are coexpressed in a network that is regulated at the transition from proliferation to quiescence and differentiation during fibroblast cell cycle withdrawal, adipogenesis in vitro, and muscle regeneration in vivo. Imprinted gene regulation is not linked to alteration of DNA methylation or to perturbation of monoallelic, parent-of-origin-dependent expression. Overexpression and knockdown of imprinted gene expression alters the sensitivity of preadipocytes to contact inhibition and adipogenic differentiation. In silico and in cellulo experiments showed that the imprinted gene network includes biallelically expressed, nonimprinted genes. These control the extracellular matrix composition, cell adhesion, cell junction, and extracellular matrix-activated and growth factor-activated signaling. These observations show that imprinted genes share a common biological process that may account for their seemingly diverse roles in embryonic development, obesity, diabetes, muscle physiology, and neoplasm.

  3. Genomic imprinting effects on cognitive and social abilities in prepubertal girls with Turner syndrome.

    Science.gov (United States)

    Lepage, Jean-François; Hong, David S; Hallmayer, Joachim; Reiss, Allan L

    2012-03-01

    Recent evidence suggests that the cognitive and social manifestations associated with Turner syndrome (TS) might be influenced by epigenetic factors in the form of genomic imprinting. However, due to small and heterogeneous samples, inconsistent results have emerged from these studies. The objective of this prospective study was to establish the impact of genomic imprinting on neurocognitive abilities and social functioning in young girls with TS. An extensive battery of neuropsychological assessments was administered to 65 children with TS who had never been exposed to estrogen treatment, 24 of whom had an X-chromosome from paternal origin (Xpat) and 41 from maternal origin (Xmat). The Wechsler scales of intelligence, the Motor-Free Visual Spatial test-3, the Wide Range Assessment of Visual Motor Ability, and the attention/executive domain of the NEPSY were used to assess cognitive abilities. Social functioning was assessed with the Social Responsiveness Scale and the Behavior Assessment System for Children-2. Results showed that although individuals with Xpat obtained lower scores than their counterparts with Xmat on most cognitive and social measures, only the Perceptual Reasoning Index of the intelligence scale yielded significant differences after correction for multiple comparisons. Overall, these results suggest that although some aspects of the neuropsychological profile of TS may be influenced by epigenetic factors, the sociocognitive phenotype associated with the disorder is not modulated by genomic imprinting.

  4. Genomic Imprinting of IGF2 Is Maintained in Infantile Hemangioma despite its High Level of Expression

    Science.gov (United States)

    Yu, Ying; Wylie-Sears, Jill; Boscolo, Elisa; Mulliken, John B; Bischoff, Joyce

    2004-01-01

    Hemangioma, the most common tumor of infancy, is characterized by rapid growth and slow regression. Increased mRNA expression of insulin-like growth factor 2 (IGF2) has been detected in the proliferating phase by cDNA microarray analysis, but the underlying mechanism causing the increase remains unknown. Here, using quantitative real-time polymerase chain reaction (PCR) and immunohistochemistry, we show that IGF2 is highly expressed in both proliferating and involuting phase hemangioma, but is not detectable in other vascular lesions such as pyogenic granuloma, venous malformation, lymphatic malformation, or in normal infant skin. Loss of imprinting of the Igf2 gene has been associated with IGF2 overexpression in a variety of childhood tumors. To determine if loss of imprinting and consequent bi-allelic expression might contribute to the increased expression of IGF2, we examined the genomic imprinting status of Igf2 in 48 individual hemangiomas. We determined allele-specific Igf2 expression using reverse transcriptase–PCR combined with analysis of an Apa I–sensitive restriction fragment length polymorphism. Similar to heterozygous normal skin controls, all 15 informative hemangiomas showed uniform mono-allelic expression of Igf2. Therefore, loss of imprinting is not involved in the increased expression of IGF2 in infantile hemangioma. PMID:15706404

  5. Maintenance of genomic imprinting at the Arabidopsis medea locus requires zygotic DDM1 activity.

    Science.gov (United States)

    Vielle-Calzada, J P; Thomas, J; Spillane, C; Coluccio, A; Hoeppner, M A; Grossniklaus, U

    1999-11-15

    In higher plants, seed development requires maternal gene activity in the haploid (gametophytic) as well as diploid (sporophytic) tissues of the developing ovule. The Arabidopsis thaliana gene MEDEA (MEA) encodes a SET-domain protein of the Polycomb group that regulates cell proliferation by exerting a gametophytic maternal control during seed development. Seeds derived from female gametocytes (embryo sacs) carrying a mutant mea allele abort and exhibit cell proliferation defects in both the embryo and the endosperm. In this study we show that the mea mutation affects an imprinted gene expressed maternally in cells of the female gametophyte and after fertilization only from maternally inherited MEA alleles. Paternally inherited MEA alleles are transcriptionally silent in both the young embryo and endosperm. Mutations at the decrease in DNA methylation1 (ddm1) locus are able to rescue mea seeds by functionally reactivating paternally inherited MEA alleles during seed development. Rescued seeds are larger than the wild type and exhibit some of the abnormalities found in aborting mea seeds. Our results indicate that the maintenance of the genomic imprint at the mea locus requires zygotic DDM1 activity. Because DDM1 encodes a putative chromatin remodeling factor, chromatin structure is likely to be interrelated with genomic imprinting in Arabidopsis.

  6. Mitochondrial complex II and genomic imprinting in inheritance of paraganglioma tumors.

    Science.gov (United States)

    Baysal, Bora E

    2013-05-01

    Germ line heterozygous mutations in the structural subunit genes of mitochondrial complex II (succinate dehydrogenase; SDH) and the regulatory gene SDHAF2 predispose to paraganglioma tumors which show constitutive activation of hypoxia inducible pathways. Mutations in SDHD and SDHAF2 cause highly penetrant multifocal tumor development after a paternal transmission, whereas maternal transmission rarely, if ever, leads to tumor development. This transmission pattern is consistent with genomic imprinting. Recent molecular evidence supports a model for tissue-specific imprinted regulation of the SDHD gene by a long range epigenetic mechanism. In addition, there is evidence of SDHB mRNA editing in peripheral blood mononuclear cells and long-term balancing selection operating on the SDHA gene. Regulation of SDH subunit expression by diverse epigenetic mechanisms implicates a crucial dosage-dependent role for SDH in oxygen homeostasis. This article is part of a Special Issue entitled: Respiratory complex II: Role in cellular physiology and disease.

  7. Evolution of genomic imprinting with biparental care: implications for Prader-Willi and Angelman syndromes.

    Directory of Open Access Journals (Sweden)

    Francisco Ubeda

    2008-08-01

    Full Text Available The term "imprinted gene" refers to genes whose expression is conditioned by their parental origin. Among theories to unravel the evolution of genomic imprinting, the kinship theory prevails as the most widely accepted, because it sheds light on many aspects of the biology of imprinted genes. While most assumptions underlying this theory have not escaped scrutiny, one remains overlooked: mothers are the only source of parental investment in mammals. But, is it reasonable to assume that fathers' contribution of resources is negligible? It is not in some key mammalian orders including humans. In this research, I generalize the kinship theory of genomic imprinting beyond maternal contribution only. In addition to deriving new conditions for the evolution of imprinting, I have found that the same gene may show the opposite pattern of expression when the investment of one parent relative to the investment of the other changes; the reversion, interestingly, does not require that fathers contribute more resources than mothers. This exciting outcome underscores the intimate connection between the kinship theory and the social structure of the organism considered. Finally, the insight gained from my model enabled me to explain the clinical phenotype of Prader-Willi syndrome. This syndrome is caused by the paternal inheritance of a deletion of the PWS/AS cluster of imprinted genes in human Chromosome 15. As such, children suffering from this syndrome exhibit a striking biphasic phenotype characterized by poor sucking and reduced weight before weaning but by voracious appetite and obesity after weaning. Interest in providing an evolutionary explanation to such phenotype is 2-fold. On the one hand, the kinship theory has been doubted as being able to explain the symptoms of patients with Prader-Willi. On the other hand, the post-weaning symptoms remain as one of the primary concern of pediatricians treating children with Prader-Willi. In this research, I

  8. Genomic imprinting: genetic mechanisms and phenotypic consequences in Prader-Willi and Angelman syndromes

    Directory of Open Access Journals (Sweden)

    Cintia Fridman

    2000-12-01

    Full Text Available Chromosomal 15q11-q13 region is of great interest in Human Genetics because many structural rearrangements have been described for it (deletions, duplications and translocations leading to phenotypes resulting in conditions such as the Prader-Willi (PWS and Angelman (AS syndromes which were the first human diseases found to be related to the differential expression of parental alleles (genomic imprinting. Contrary to Mendelian laws where the parental inheritance of genetic information does not influence gene expression, genomic imprinting is characterized by DNA modifications that produce different phenotypes depending on the parental origin of the mutation. Clinical manifestation of PWS appears when the loss of paternally expressed genes occurs and AS results from the loss of a maternally expressed gene. Different genetic mechanisms can lead to PWS or AS, such as deletions, uniparental disomy or imprinting mutation. In AS patients an additional class occurs with mutations on the UBE3A gene. Studies of PWS and AS patients can help us to understand the imprinting process, so that other genomic regions with similar characteristics can be located, and different syndromes can have their genetic mechanisms elucidated.O segmento cromossômico 15q11-q13 é de grande interesse em Genética Humana uma vez que diversos rearranjos estruturais têm sido descritos nessa região (deleções, duplicações e translocações resultando em fenótipos diferentes como os das síndromes de Prader-Willi (PWS e Angelman (AS, que foram as primeiras doenças humanas a serem relacionadas com a expressão diferencial de alelos parentais (imprinting genômico. Contrário às leis de Mendel onde a herança parental da informação genética não influencia a expressão gênica, o imprinting genômico é caracterizado por modificações no DNA que produzem diferentes fenótipos dependendo da origem parental da mutação. A manifestação clínica da PWS aparece quando

  9. The battle of the sexes over seed size: support for both kinship genomic imprinting and interlocus contest evolution.

    Science.gov (United States)

    Willi, Yvonne

    2013-06-01

    Outcrossing creates a venue for parental conflict. When one sex provides parental care to offspring fertilized by several partners, the nonproviding sex is under selection to maximally exploit the caring sex. The caring sex may counteradapt, and a coevolutionary arms race ensues. Genetic models of this conflict include the kinship theory of genomic imprinting (parent-of-origin-specific expression of maternal-care effectors) and interlocus conflict evolution (interaction between male selfish signals and female abatement). Predictions were tested by measuring the sizes of seeds produced by within-population crosses (diallel design) and between-population crosses in outcrossing and selfing populations of Arabidopsis lyrata. Within-population diallel crosses revealed substantial maternal variance in seed size in most populations. The comparison of between- and within-population crosses showed that seeds were larger when pollen came from another outcrossing population than when pollen came from a selfing or the same population, supporting interlocus contest evolution between male selfish genes and female recognition genes. Evidence for kinship genomic imprinting came from complementary trait means of seed size in reciprocal between-population crosses independent of whether populations were predominantly selfing or outcrossing. Hence, both kinship genomic imprinting and interlocus contest are supported in outcrossing Arabidopsis, whereas only kinship genomic imprinting is important in selfing populations.

  10. A small family of sushi-class retrotransposon-derived genes in mammals and their relation to genomic imprinting.

    Science.gov (United States)

    Youngson, Neil A; Kocialkowski, Sylvia; Peel, Nina; Ferguson-Smith, Anne C

    2005-10-01

    Ty3/gypsy retrotransposons are rare in mammalian genomes despite their abundance in invertebrate and other vertebrate classes. Here we identify a family of nine conserved mammalian genes with homology to Ty3/gypsy retrotransposons but which have lost their ability to autonomously retrotranspose. Of these, five map to the X chromosome while the remaining four are autosomal. Comparative phylogenetic analyses show them to have strongest homology to the sushi-ichi element from Fugu rubripes. Two of the autosomal gene members, Peg10 and Rtl1, are known to be imprinted, being expressed from the paternally inherited chromosome homologue. This suggests, consistent with the host-parasite response theory of the evolution of the imprinting mechanism, that parental-origin specific epigenetic control may be mediated by genomic "parasitic" elements such as these. Alternatively, these elements may preferentially integrate into regions that are differentially modified on the two homologous chromosomes such as imprinted domains and the X chromosome and acquire monoallelic expression. We assess the imprinting status of the remaining autosomal members of this family and show them to be biallelically expressed in embryo and placenta. Furthermore, the methylation status of Rtl1 was assayed throughout development and was found to resemble that of actively, silenced repetitive elements rather than imprinted sequences. This indicates that the ability to undergo genomic imprinting is not an inherent property of all members of this family of retroelements. Nonetheless, the conservation but functional divergence between the different members suggests that they have undergone positive selection and acquired distinct endogenous functions within their mammalian hosts.

  11. Tumor Touch Imprints as Source for Whole Genome Analysis of Neuroblastoma Tumors

    Science.gov (United States)

    Brunner, Clemens; Brunner-Herglotz, Bettina; Ziegler, Andrea; Frech, Christian; Amann, Gabriele; Ladenstein, Ruth; Ambros, Inge M.; Ambros, Peter F.

    2016-01-01

    Introduction Tumor touch imprints (TTIs) are routinely used for the molecular diagnosis of neuroblastomas by interphase fluorescence in-situ hybridization (I-FISH). However, in order to facilitate a comprehensive, up-to-date molecular diagnosis of neuroblastomas and to identify new markers to refine risk and therapy stratification methods, whole genome approaches are needed. We examined the applicability of an ultra-high density SNP array platform that identifies copy number changes of varying sizes down to a few exons for the detection of genomic changes in tumor DNA extracted from TTIs. Material and Methods DNAs were extracted from TTIs of 46 neuroblastoma and 4 other pediatric tumors. The DNAs were analyzed on the Cytoscan HD SNP array platform to evaluate numerical and structural genomic aberrations. The quality of the data obtained from TTIs was compared to that from randomly chosen fresh or fresh frozen solid tumors (n = 212) and I-FISH validation was performed. Results SNP array profiles were obtained from 48 (out of 50) TTI DNAs of which 47 showed genomic aberrations. The high marker density allowed for single gene analysis, e.g. loss of nine exons in the ATRX gene and the visualization of chromothripsis. Data quality was comparable to fresh or fresh frozen tumor SNP profiles. SNP array results were confirmed by I-FISH. Conclusion TTIs are an excellent source for SNP array processing with the advantage of simple handling, distribution and storage of tumor tissue on glass slides. The minimal amount of tumor tissue needed to analyze whole genomes makes TTIs an economic surrogate source in the molecular diagnostic work up of tumor samples. PMID:27560999

  12. Congenital imprinting disorders

    DEFF Research Database (Denmark)

    Eggermann, Thomas; Netchine, Irène; Temple, I Karen

    2015-01-01

    Imprinting disorders (IDs) are a group of eight rare but probably underdiagnosed congenital diseases affecting growth, development and metabolism. They are caused by similar molecular changes affecting regulation, dosage or the genomic sequence of imprinted genes. Each ID is characterised...... EUCID.net (European network of congenital imprinting disorders) now aims to promote better clinical care and scientific investigation of imprinting disorders by establishing a concerted multidisciplinary alliance of clinicians, researchers, patients and families. By encompassing all IDs and establishing...

  13. Imprinting in plants

    Institute of Scientific and Technical Information of China (English)

    GUTIERREZ-MARCOS Jose

    2009-01-01

    Genomic imprinting leads to the differential expression of parental alleles after fertilization. Imprinting appears to have evolved independently in mammals and flowering plants to regulate the development of nutrient-transfer placental tissues. In addition, the regulation of imprinting in both mammals and flowering plants involves changes in DNA methylation and histone methylation, thus suggesting that the epigenetic signals that regulate imprinting have been co-opted in these distantly related species.

  14. Genome-wide multilocus imprinting disturbance analysis in Temple syndrome and Kagami-Ogata syndrome.

    Science.gov (United States)

    Kagami, Masayo; Matsubara, Keiko; Nakabayashi, Kazuhiko; Nakamura, Akie; Sano, Shinichiro; Okamura, Kohji; Hata, Kenichiro; Fukami, Maki; Ogata, Tsutomu

    2017-04-01

    Recent studies have identified multilocus imprinting disturbances (MLIDs) in a subset of patients with imprinting diseases (IDs) caused by epimutations. We examined MLIDs in patients with Temple syndrome (TS14) and Kagami-Ogata syndrome (KOS14). We studied four TS14 patients (patients 1-4) and five KOS14 patients (patients 5-9) with epimutations. We performed HumanMethylation450 BeadChip (HM450k) analysis for 43 differentially methylated regions (DMRs) (753 CpG sites) and pyrosequencing for 12 DMRs (62 CpG sites) using leukocyte genomic DNA (Leu-gDNA) of patients 1-9, and performed HM450k analysis for 43 DMRs (a slightly different set of 753 CpG sites) using buccal cell gDNA (Buc-gDNA) of patients 1, 3, and 4. We also performed mutation analysis for six causative and candidate genes for MLIDs and quantitative expression analysis using immortalized lymphocytes in MLID-positive patients. Methylation analysis showed hypermethylated ZDBF2-DMR and ZNF597/NAA60-DMR, hypomethylated ZNF597-DMR in both Leu-gDNA and Buc-gDNA, and hypomethylated PPIEL-DMR in Buc-gDNA of patient 1, and hypermethylated GNAS-A/B-DMR in Leu-gDNA of patient 3. No mutations were detected in the six genes for MLIDs. Expression patterns of ZDBF2, ZNF597, and GNAS-A/B were consistent with the identified MLIDs. This study indicates the presence of MLIDs in TS14 patients but not in KOS14 patients.Genet Med 19 4, 476-482.

  15. Genomic imprinting on the X chromosome: implications for brain and behavioral phenotypes.

    Science.gov (United States)

    Davies, William

    2010-09-01

    Imprinted genes, in contrast to most mammalian genes, are monoallelically expressed in a parent-of-origin dependent manner. The idiosyncratic expression profile associated with imprinted genes arises from the differential epigenetic marking of the alleles in the paternal and maternal germlines. Although small in number, imprinted genes can profoundly influence key developmental and physiological processes, including those in the brain; work in animal models and in humans has shown that such genes can affect behavioral traits and cognition and may confer vulnerability to common mental illnesses. As a consequence of how the X chromosome is inherited, X-linked imprinting may elicit or indeed attenuate sexually dimorphic phenotypes. Thus, studying X-linked imprinting is likely to provide important general information about the evolutionary and mechanistic underpinnings of imprinting, as well as the molecular processes underlying sex-specific neurobiology and sex-biased vulnerability to psychiatric disorders.

  16. Research Progress in Genomic Imprinting in Mammals%哺乳动物基因组印记的研究进展

    Institute of Scientific and Technical Information of China (English)

    陈秀莉; 马利兵

    2015-01-01

    Genomic imprinting is a genetic phenomenon because of the different parents resulted from the allelic gene expression differences. The causes and the process of genomic imprinting is a hot issue of modern genetics. Mammals many genomic imprinting characteristic makes it become a focus biology problems in the post genome era. The evolution of genomic imprinting has played a special role in mammalian reproduction and development. This paper reviewed the characteristics of genomic imprinting、imprinting mechanism of gene imprinting, gene imprinting and the development of cloned animals, the research progress of the imprinting genes and the disease.%基因组印记是由亲本来源不同而导致等位基因表达差异的一种遗传现象。基因组印记产生的原因及过程是现代遗传学的一个热点问题。哺乳动物的许多基因组印记特征都使其成为后基因组时代的一个热点生物学问题。进化的基因组印记在哺乳动物生殖、发育中起到了特定的作用。综述了基因组印记的特点、印记基因的印记机理、基因印记与克隆动物的发育、印记基因与疾病的研究进展。

  17. Genomic imprinting: potential function and mechanisms revealed by the Prader-Willi and Angelman syndromes.

    Science.gov (United States)

    Glenn, C C; Driscoll, D J; Yang, T P; Nicholls, R D

    1997-04-01

    The Prader-Willi (PWS) and Angelman (AS) syndromes are two clinically distinct syndromes which result from lack of expression of imprinted genes within chromosome 15q11-q13. These two syndromes result from 15q11-q13 deletions, chromosome 15 uniparental disomy (UPD), imprinting centre mutations and, for AS, probable mutations in a single gene. The differential phenotype results from a paternal genetic deficiency in PWS patients and a maternal genetic deficiency in AS patients. Within 15q11-q13, four genes (SNRPN, IPW, ZNF127, FNZ127) and two expressed sequence tags (PAR1 and PAR5) have been found to be expressed only from the paternally inherited chromosome, and therefore all must be considered candidate genes involved in the pathogenesis of PWS. A candidate AS gene (UBE3A) has very recently been identified. The mechanisms of imprinted gene expression are not yet understood, but it is clear that DNA methylation is involved in both somatic cell expression and inheritance of the imprint. The presence of DNA methylation imprints that distinguish the paternally and maternally inherited alleles is a common characteristic of all known imprinted genes which have been studied extensively, including SNRPN and ZNF127. Recently, several PWS and AS patients have been found that have microdeletions in a region upstream of the SNRPN gene referred to as the imprinting centre, or IC. Paternal IC deletions in PWS patients and maternal IC deletions in AS patients result in uniparental DNA methylation and uniparental gene expression at biparentally inherited loci. The IC is a novel genetic element which controls initial resetting of the parental imprint in the germline for all imprinted gene expression over a 1.5-2.5 Mb region within chromosome 15q11-q13.

  18. Dissecting genomic imprinting and genetic conflict from a game theory prospective. Comment on: ;Epigenetic game theory: How to compute the epigenetic control of maternal-to-zygotic transition; by Qian Wang et al.

    Science.gov (United States)

    Cui, Yuehua; Yang, Haitao

    2017-03-01

    Epigenetics typically refers to changes in the structure of a chromosome that affect gene activity and expression. Genomic imprinting is a special type of epigenetic phenomenon in which the expression of an allele depends on its parental origin. When an allele inherited from the mother (or father) is imprinted (i.e., silent), it is termed as maternal (or paternal) imprinting. Imprinting is often resulted from DNA methylation and tends to cluster together in the genome [1]. It has been shown to play a key role in many genetic disorders in humans [2]. Imprinting is heritable and undergoes a reprogramming process in gametes before and after fertilization [1]. Sometimes the reprogramming process is not reversible, leading to the loss of imprinting [3]. Although efforts have been made to experimentally or computationally infer imprinting genes, the underlying molecular mechanism that leads to unbalanced allelic expression is still largely unknown.

  19. Pairing of Homologous Regions in the Mouse Genome Is Associated with Transcription but Not Imprinting Status

    Science.gov (United States)

    Krueger, Christel; King, Michelle R.; Krueger, Felix; Branco, Miguel R.; Osborne, Cameron S.; Niakan, Kathy K.; Higgins, Michael J.; Reik, Wolf

    2012-01-01

    Although somatic homologous pairing is common in Drosophila it is not generally observed in mammalian cells. However, a number of regions have recently been shown to come into close proximity with their homologous allele, and it has been proposed that pairing might be involved in the establishment or maintenance of monoallelic expression. Here, we investigate the pairing properties of various imprinted and non-imprinted regions in mouse tissues and ES cells. We find by allele-specific 4C-Seq and DNA FISH that the Kcnq1 imprinted region displays frequent pairing but that this is not dependent on monoallelic expression. We demonstrate that pairing involves larger chromosomal regions and that the two chromosome territories come close together. Frequent pairing is not associated with imprinted status or DNA repair, but is influenced by chromosomal location and transcription. We propose that homologous pairing is not exclusive to specialised regions or specific functional events, and speculate that it provides the cell with the opportunity of trans-allelic effects on gene regulation. PMID:22802932

  20. Uniparental disomy (UPD). Genomic imprinting and a case for new genetics (prenatal and clinical implications: the "Likon" concept).

    Science.gov (United States)

    Engel, E

    1997-01-01

    Uniparental disomy (UPD) is often the result of an aneuploid event masquerading under the features of diploidy. As such, it may never be recognized, being at 2 opposite phenotypic poles, harmless to the bearer, or, if harmful, eventually responsible for uncharacteristic although perhaps serious conditions. UPD can also be associated with problems such as recessiveness or mosaicism. This article considers the chances of unmasking UPD, in the course of CVS or AC prenatal diagnosis, by reviewing the main cytogenetic signals and major familial or personal antecedents raising its suspicion. Once suspected, the lead toward UPD may or may not be followed through appropriate molecular studies. UPD for either maternal or paternal chromosomes 13, 21 and 22 may not have consistent, common deleterious effects, while other identified UPD's are too rare to call. Unconditionally, main, consistent or near consistent damages to the phenotype have been traced to specific chromosome pairs such as 15 mat (Prader-Willi syndrome), 15 pat (Angelman syndrome), 11 pat (Wiedemann-Beck with syndrome), 14 mat and pat (multiple cogenital and developmental anomalies [MCDA]-several rather constant) and 7 mat (Russel-Silver [RS] and Growth-failure [GF]). The above problems all stem from an alteration of the normal, developmentally important genomic imprinting processes and most of them may recognize several etiopathogenic paths, other than UPD, none of which abides by straight Mendelian rules. In this very area, therefore, a new, non-traditional type of inheritance is confronting genetic counselling. In this paper, for want of appropriate semantic language, the neologism "likon" (or "laïkon") is coined to make reference to the hemizygously expressed sequences of the genomic parts imprinted in the somatic tissues. Broadening the definition, the word is then applied to the 4 possible epigenotypes of imprinted domains, which depend on the parental sex-of-origin: germinally "resting" (R), or "acting

  1. Genomic imprinting variations in the mouse type 3 deiodinase gene between tissues and brain regions.

    Science.gov (United States)

    Martinez, M Elena; Charalambous, Marika; Saferali, Aabida; Fiering, Steven; Naumova, Anna K; St Germain, Donald; Ferguson-Smith, Anne C; Hernandez, Arturo

    2014-11-01

    The Dio3 gene, which encodes for the type 3 deiodinase (D3), controls thyroid hormone (TH) availability. The lack of D3 in mice results in tissue overexposure to TH and a broad neuroendocrine phenotype. Dio3 is an imprinted gene, preferentially expressed from the paternally inherited allele in the mouse fetus. However, heterozygous mice with paternal inheritance of the inactivating Dio3 mutation exhibit an attenuated phenotype when compared with that of Dio3 null mice. To investigate this milder phenotype, the allelic expression of Dio3 was evaluated in different mouse tissues. Preferential allelic expression of Dio3 from the paternal allele was observed in fetal tissues and neonatal brain regions, whereas the biallelic Dio3 expression occurred in the developing eye, testes, and cerebellum and in the postnatal brain neocortex, which expresses a larger Dio3 mRNA transcript. The newborn hypothalamus manifests the highest degree of Dio3 expression from the paternal allele, compared with other brain regions, and preferential allelic expression of Dio3 in the brain relaxed in late neonatal life. A methylation analysis of two regulatory regions of the Dio3 imprinted domain revealed modest but significant differences between tissues, but these did not consistently correlate with the observed patterns of Dio3 allelic expression. Deletion of the Dio3 gene and promoter did not result in significant changes in the tissue-specific patterns of Dio3 allelic expression. These results suggest the existence of unidentified epigenetic determinants of tissue-specific Dio3 imprinting. The resulting variation in the Dio3 allelic expression between tissues likely explains the phenotypic variation that results from paternal Dio3 haploinsufficiency.

  2. Ectomycorrhizal ecology is imprinted in the genome of the dominant symbiotic fungus Cenococcum geophilum

    NARCIS (Netherlands)

    Peter, Martina; Kohler, Annegret; Ohm, Robin A.; Kuo, Alan; Krützmann, Jennifer; Morin, Emmanuelle; Arend, Matthias; Barry, Kerrie W.; Binder, Manfred; Choi, Cindy; Clum, Alicia; Copeland, Alex; Grisel, Nadine; Haridas, Sajeet; Kipfer, Tabea; LaButti, Kurt; Lindquist, Erika; Lipzen, Anna; Maire, Renaud; Meier, Barbara; Mihaltcheva, Sirma; Molinier, Virginie; Murat, Claude; Pöggeler, Stefanie; Quandt, C. Alisha; Sperisen, Christoph; Tritt, Andrew; Tisserant, Emilie; Crous, Pedro W.; Henrissat, Bernard; Nehls, Uwe; Egli, Simon; Spatafora, Joseph W.; Grigoriev, Igor V.; Martin, Francis M.

    2016-01-01

    The most frequently encountered symbiont on tree roots is the ascomycete Cenococcum geophilum, the only mycorrhizal species within the largest fungal class Dothideomycetes, a class known for devastating plant pathogens. Here we show that the symbiotic genomic idiosyncrasies of ectomycorrhizal

  3. Universal global imprints of genome growth and evolution--equivalent length and cumulative mutation density.

    Directory of Open Access Journals (Sweden)

    Hong-Da Chen

    Full Text Available BACKGROUND: Segmental duplication is widely held to be an important mode of genome growth and evolution. Yet how this would affect the global structure of genomes has been little discussed. METHODS/PRINCIPAL FINDINGS: Here, we show that equivalent length, or L(e, a quantity determined by the variance of fluctuating part of the distribution of the k-mer frequencies in a genome, characterizes the latter's global structure. We computed the L(es of 865 complete chromosomes and found that they have nearly universal but (k-dependent values. The differences among the L(e of a chromosome and those of its coding and non-coding parts were found to be slight. CONCLUSIONS: We verified that these non-trivial results are natural consequences of a genome growth model characterized by random segmental duplication and random point mutation, but not of any model whose dominant growth mechanism is not segmental duplication. Our study also indicates that genomes have a nearly universal cumulative "point" mutation density of about 0.73 mutations per site that is compatible with the relatively low mutation rates of (1-5 x 10(-3/site/Mya previously determined by sequence comparison for the human and E. coli genomes.

  4. Imprinting is also a mechanism for immediate or delayed hemizygous expression of several uniparental haplotypes selected from the genome of each sex.

    Science.gov (United States)

    Engel, E

    1997-05-02

    A peculiar and interesting aspect of monoallelic or hemizygous expression, resulting from genomic imprinting, should be a likeness or resemblance for some phenotypic traits between relatives inheriting identical active genes or domains. Although the word "likon," a neologism, is reminiscent of the above implication, it is here proposed for use in a broader sense, namely, to designate a haplotype or part of a haplotype of an imprinted domain. As learned from earlier studies of imprinting and uniparental disomies, haplotypes at loci of such domains may be expressed (E) or unexpressed (U) in somatic cells; they may also be transmitted to be expressed or not in the next generation by germ cells "acting" (A) or marked to be "resting" (R) for such loci. Thus the soma/germinal status of "likons" might for each genitor be abbreviated as EA, UA, ER, and UR. In an evolutionary sense the assumption is that the same monoallelically expressed loci and domains when carried by two or more relatives should be the source of identical transcripts contributing to a closely similar phenotype. If so, the overall phenotype would be distinct if arising from some 10 to 20 imprinted genes or domains potentially gaining expression from the germ cells of either one or the other sex in humans. The result may have evolutionary implications by narrowing the scope of random individual variation and by strengthening assortative and associative values (physical, behavioral, and instinctual) in one's own lineage and species.

  5. Host imprints on bacterial genomes--rapid, divergent evolution in individual patients.

    Directory of Open Access Journals (Sweden)

    Jaroslaw Zdziarski

    Full Text Available Bacteria lose or gain genetic material and through selection, new variants become fixed in the population. Here we provide the first, genome-wide example of a single bacterial strain's evolution in different deliberately colonized patients and the surprising insight that hosts appear to personalize their microflora. By first obtaining the complete genome sequence of the prototype asymptomatic bacteriuria strain E. coli 83972 and then resequencing its descendants after therapeutic bladder colonization of different patients, we identified 34 mutations, which affected metabolic and virulence-related genes. Further transcriptome and proteome analysis proved that these genome changes altered bacterial gene expression resulting in unique adaptation patterns in each patient. Our results provide evidence that, in addition to stochastic events, adaptive bacterial evolution is driven by individual host environments. Ongoing loss of gene function supports the hypothesis that evolution towards commensalism rather than virulence is favored during asymptomatic bladder colonization.

  6. Ectomycorrhizal ecology is imprinted in the genome of the dominant symbiotic fungus Cenococcum geophilum

    NARCIS (Netherlands)

    Peter, Martina; Kohler, Annegret; Ohm, Robin A|info:eu-repo/dai/nl/304837628; Kuo, Alan; Krützmann, Jennifer; Morin, Emmanuelle; Arend, Matthias; Barry, Kerrie W; Binder, Manfred; Choi, Cindy; Clum, Alicia; Copeland, Alex; Grisel, Nadine; Haridas, Sajeet; Kipfer, Tabea; LaButti, Kurt; Lindquist, Erika; Lipzen, Anna; Maire, Renaud; Meier, Barbara; Mihaltcheva, Sirma; Molinier, Virginie; Murat, Claude; Pöggeler, Stefanie; Quandt, C Alisha; Sperisen, Christoph; Tritt, Andrew; Tisserant, Emilie; Crous, Pedro W|info:eu-repo/dai/nl/252069927; Henrissat, Bernard; Nehls, Uwe; Egli, Simon; Spatafora, Joseph W; Grigoriev, Igor V; Martin, Francis M

    2016-01-01

    The most frequently encountered symbiont on tree roots is the ascomycete Cenococcum geophilum, the only mycorrhizal species within the largest fungal class Dothideomycetes, a class known for devastating plant pathogens. Here we show that the symbiotic genomic idiosyncrasies of ectomycorrhizal basidi

  7. Genomic imbalance in the centromeric 11p15 imprinting center in three families: Further evidence of a role for IC2 as a cause of Russell-Silver syndrome.

    Science.gov (United States)

    Cytrynbaum, Cheryl; Chong, Karen; Hannig, Vickie; Choufani, Sanaa; Shuman, Cheryl; Steele, Leslie; Morgan, Thomas; Scherer, Stephen W; Stavropoulos, Dimitri J; Basran, Raveen K; Weksberg, Rosanna

    2016-10-01

    Russell-Silver syndrome is a heterogeneous disorder characterized by intrauterine growth retardation, postnatal growth deficiency, characteristic facial appearance, and other variable features. Genetic and epigenetic alterations are identified in about 60% of individuals with Russell-Silver syndrome. Most frequently, Russell-Silver syndrome is caused by altered gene expression on chromosome 11p15 due to loss of methylation at the telomeric imprinting center. To date there have been a handful of isolated clinical reports implicating the centromeric imprinting center 2 in the etiology of Russell-Silver syndrome. Here we report three new families with genomic imbalances, involving imprinting center 2 resulting in gain of methylation at this center and a Russell-Silver syndrome phenotype, including two families with a maternally inherited microduplication and the first pediatric patient with a paternally derived microdeletion. The findings in our families provide additional evidence of a role for imprinting center 2 in the etiology of Russell-Silver syndrome and suggest that imprinting center 2 imprinting abnormalities may be a more common cause of Russell-Silver syndrome than previously recognized. Furthermore, our findings together with previous clinical reports of genomic imbalances involving imprinting center 2 serve to underscore the complexity of the epigenetic regulation of the 11p15 region making it challenging to predict phenotype on the basis of genotype alone. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Genome-wide screen of genes imprinted in sorghum endosperm, and the roles of allelic differential cytosine methylation.

    Science.gov (United States)

    Zhang, Meishan; Li, Ning; He, Wenan; Zhang, Huakun; Yang, Wei; Liu, Bao

    2016-02-01

    Imprinting is an epigenetic phenomenon referring to allele-biased expression of certain genes depending on their parent of origin. Accumulated evidence suggests that, while imprinting is a conserved mechanism across kingdoms, the identities of the imprinted genes are largely species-specific. Using deep RNA sequencing of endosperm 14 days after pollination in sorghum, 5683 genes (29.27% of the total 19 418 expressed genes) were found to harbor diagnostic single nucleotide polymorphisms between two parental lines. The analysis of parent-of-origin expression patterns in the endosperm of a pair of reciprocal F1 hybrids between the two sorghum lines led to identification of 101 genes with ≥ fivefold allelic expression difference in both hybrids, including 85 maternal expressed genes (MEGs) and 16 paternal expressed genes (PEGs). Thirty of these genes were previously identified as imprinted in endosperm of maize (Zea mays), rice (Oryza sativa) or Arabidopsis, while the remaining 71 genes are sorghum-specific imprinted genes relative to these three plant species. Allele-biased expression of virtually all of the 14 tested imprinted genes (nine MEGs and five PEGs) was validated by pyrosequencing using independent sources of RNA from various developmental stages and dissected parts of endosperm. Forty-six imprinted genes (30 MEGs and 16 PEGs) were assayed by quantitative RT-PCR, and the majority of them showed endosperm-specific or preferential expression relative to embryo and other tissues. DNA methylation analysis of the 5' upstream region and gene body for seven imprinted genes indicated that, while three of the four PEGs were associated with hypomethylation of maternal alleles, no MEG was associated with allele-differential methylation.

  9. Donkey genome and insight into the imprinting of fast karyotype evolution.

    Science.gov (United States)

    Huang, Jinlong; Zhao, Yiping; Bai, Dongyi; Shiraigol, Wunierfu; Li, Bei; Yang, Lihua; Wu, Jing; Bao, Wuyundalai; Ren, Xiujuan; Jin, Burenqiqige; Zhao, Qinan; Li, Anaer; Bao, Sarula; Bao, Wuyingga; Xing, Zhencun; An, Aoruga; Gao, Yahan; Wei, Ruiyuan; Bao, Yirugeletu; Bao, Taoketao; Han, Haige; Bai, Haitang; Bao, Yanqing; Zhang, Yuhong; Daidiikhuu, Dorjsuren; Zhao, Wenjing; Liu, Shuyun; Ding, Jinmei; Ye, Weixing; Ding, Fangmei; Sun, Zikui; Shi, Yixiang; Zhang, Yan; Meng, He; Dugarjaviin, Manglai

    2015-09-16

    The donkey, like the horse, is a promising model for exploring karyotypic instability. We report the de novo whole-genome assemblies of the donkey and the Asiatic wild ass. Our results reflect the distinct characteristics of donkeys, including more effective energy metabolism and better immunity than horses. The donkey shows a steady demographic trajectory. We detected abundant satellite sequences in some inactive centromere regions but not in neocentromere regions, while ribosomal RNAs frequently emerged in neocentromere regions but not in the obsolete centromere regions. Expanded miRNA families and five newly discovered miRNA target genes involved in meiosis may be associated with fast karyotype evolution. APC/C, controlling sister chromatid segregation, cytokinesis, and the establishment of the G1 cell cycle phase were identified by analysis of miRNA targets and rapidly evolving genes.

  10. The evolutionary imprint of domestication on genome variation and function of the filamentous fungus Aspergillus oryzae.

    Science.gov (United States)

    Gibbons, John G; Salichos, Leonidas; Slot, Jason C; Rinker, David C; McGary, Kriston L; King, Jonas G; Klich, Maren A; Tabb, David L; McDonald, W Hayes; Rokas, Antonis

    2012-08-01

    The domestication of animals, plants, and microbes fundamentally transformed the lifestyle and demography of the human species [1]. Although the genetic and functional underpinnings of animal and plant domestication are well understood, little is known about microbe domestication [2-6]. Here, we systematically examined genome-wide sequence and functional variation between the domesticated fungus Aspergillus oryzae, whose saccharification abilities humans have harnessed for thousands of years to produce sake, soy sauce, and miso from starch-rich grains, and its wild relative A. flavus, a potentially toxigenic plant and animal pathogen [7]. We discovered dramatic changes in the sequence variation and abundance profiles of genes and wholesale primary and secondary metabolic pathways between domesticated and wild relative isolates during growth on rice. Our data suggest that, through selection by humans, an atoxigenic lineage of A. flavus gradually evolved into a "cell factory" for enzymes and metabolites involved in the saccharification process. These results suggest that whereas animal and plant domestication was largely driven by Neolithic "genetic tinkering" of developmental pathways, microbe domestication was driven by extensive remodeling of metabolism.

  11. DNA sequence polymorphisms within the bovine guanine nucleotide-binding protein Gs subunit alpha (Gsα-encoding (GNAS genomic imprinting domain are associated with performance traits

    Directory of Open Access Journals (Sweden)

    Mullen Michael P

    2011-01-01

    Full Text Available Abstract Background Genes which are epigenetically regulated via genomic imprinting can be potential targets for artificial selection during animal breeding. Indeed, imprinted loci have been shown to underlie some important quantitative traits in domestic mammals, most notably muscle mass and fat deposition. In this candidate gene study, we have identified novel associations between six validated single nucleotide polymorphisms (SNPs spanning a 97.6 kb region within the bovine guanine nucleotide-binding protein Gs subunit alpha gene (GNAS domain on bovine chromosome 13 and genetic merit for a range of performance traits in 848 progeny-tested Holstein-Friesian sires. The mammalian GNAS domain consists of a number of reciprocally-imprinted, alternatively-spliced genes which can play a major role in growth, development and disease in mice and humans. Based on the current annotation of the bovine GNAS domain, four of the SNPs analysed (rs43101491, rs43101493, rs43101485 and rs43101486 were located upstream of the GNAS gene, while one SNP (rs41694646 was located in the second intron of the GNAS gene. The final SNP (rs41694656 was located in the first exon of transcripts encoding the putative bovine neuroendocrine-specific protein NESP55, resulting in an aspartic acid-to-asparagine amino acid substitution at amino acid position 192. Results SNP genotype-phenotype association analyses indicate that the single intronic GNAS SNP (rs41694646 is associated (P ≤ 0.05 with a range of performance traits including milk yield, milk protein yield, the content of fat and protein in milk, culled cow carcass weight and progeny carcass conformation, measures of animal body size, direct calving difficulty (i.e. difficulty in calving due to the size of the calf and gestation length. Association (P ≤ 0.01 with direct calving difficulty (i.e. due to calf size and maternal calving difficulty (i.e. due to the maternal pelvic width size was also observed at the rs

  12. DNA sequence polymorphisms within the bovine guanine nucleotide-binding protein Gs subunit alpha (Gsα)-encoding (GNAS) genomic imprinting domain are associated with performance traits

    Science.gov (United States)

    2011-01-01

    Background Genes which are epigenetically regulated via genomic imprinting can be potential targets for artificial selection during animal breeding. Indeed, imprinted loci have been shown to underlie some important quantitative traits in domestic mammals, most notably muscle mass and fat deposition. In this candidate gene study, we have identified novel associations between six validated single nucleotide polymorphisms (SNPs) spanning a 97.6 kb region within the bovine guanine nucleotide-binding protein Gs subunit alpha gene (GNAS) domain on bovine chromosome 13 and genetic merit for a range of performance traits in 848 progeny-tested Holstein-Friesian sires. The mammalian GNAS domain consists of a number of reciprocally-imprinted, alternatively-spliced genes which can play a major role in growth, development and disease in mice and humans. Based on the current annotation of the bovine GNAS domain, four of the SNPs analysed (rs43101491, rs43101493, rs43101485 and rs43101486) were located upstream of the GNAS gene, while one SNP (rs41694646) was located in the second intron of the GNAS gene. The final SNP (rs41694656) was located in the first exon of transcripts encoding the putative bovine neuroendocrine-specific protein NESP55, resulting in an aspartic acid-to-asparagine amino acid substitution at amino acid position 192. Results SNP genotype-phenotype association analyses indicate that the single intronic GNAS SNP (rs41694646) is associated (P ≤ 0.05) with a range of performance traits including milk yield, milk protein yield, the content of fat and protein in milk, culled cow carcass weight and progeny carcass conformation, measures of animal body size, direct calving difficulty (i.e. difficulty in calving due to the size of the calf) and gestation length. Association (P ≤ 0.01) with direct calving difficulty (i.e. due to calf size) and maternal calving difficulty (i.e. due to the maternal pelvic width size) was also observed at the rs43101491 SNP. Following

  13. An imprinted non-coding genomic cluster at 14q32 defines clinically relevant molecular subtypes in osteosarcoma across multiple independent datasets.

    Science.gov (United States)

    Hill, Katherine E; Kelly, Andrew D; Kuijjer, Marieke L; Barry, William; Rattani, Ahmed; Garbutt, Cassandra C; Kissick, Haydn; Janeway, Katherine; Perez-Atayde, Antonio; Goldsmith, Jeffrey; Gebhardt, Mark C; Arredouani, Mohamed S; Cote, Greg; Hornicek, Francis; Choy, Edwin; Duan, Zhenfeng; Quackenbush, John; Haibe-Kains, Benjamin; Spentzos, Dimitrios

    2017-05-15

    A microRNA (miRNA) collection on the imprinted 14q32 MEG3 region has been associated with outcome in osteosarcoma. We assessed the clinical utility of this miRNA set and their association with methylation status. We integrated coding and non-coding RNA data from three independent annotated clinical osteosarcoma cohorts (n = 65, n = 27, and n = 25) and miRNA and methylation data from one in vitro (19 cell lines) and one clinical (NCI Therapeutically Applicable Research to Generate Effective Treatments (TARGET) osteosarcoma dataset, n = 80) dataset. We used time-dependent receiver operating characteristic (tdROC) analysis to evaluate the clinical value of candidate miRNA profiles and machine learning approaches to compare the coding and non-coding transcriptional programs of high- and low-risk osteosarcoma tumors and high- versus low-aggressiveness cell lines. In the cell line and TARGET datasets, we also studied the methylation patterns of the MEG3 imprinting control region on 14q32 and their association with miRNA expression and tumor aggressiveness. In the tdROC analysis, miRNA sets on 14q32 showed strong discriminatory power for recurrence and survival in the three clinical datasets. High- or low-risk tumor classification was robust to using different microRNA sets or classification methods. Machine learning approaches showed that genome-wide miRNA profiles and miRNA regulatory networks were quite different between the two outcome groups and mRNA profiles categorized the samples in a manner concordant with the miRNAs, suggesting potential molecular subtypes. Further, miRNA expression patterns were reproducible in comparing high-aggressiveness versus low-aggressiveness cell lines. Methylation patterns in the MEG3 differentially methylated region (DMR) also distinguished high-aggressiveness from low-aggressiveness cell lines and were associated with expression of several 14q32 miRNAs in both the cell lines and the large TARGET clinical dataset

  14. Sex of parent transmission effect in Tourette's syndrome: evidence for earlier age at onset in maternally transmitted cases suggests a genomic imprinting effect.

    Science.gov (United States)

    Eapen, V; O'Neill, J; Gurling, H M; Robertson, M M

    1997-04-01

    Parent of origin effects caused by genomic imprinting may influence the phenotypic expression of a number of heritable human disorders. To test this phenomenon in Tourette's syndrome (TS), we studied 437 first degree relatives systematically ascertained through 57 probands. We compared age at onset, age at diagnosis, and phenotypic expressions as observed in the diagnosis of TS, chronic motor tics, and obsessive compulsive behavior in the offspring of affected males with the offspring of affected females. Of the 437 subjects, 16.7% had matrilineal inheritance and 13.9% had patrilineal inheritance, as determined by family history methodology. Chi-square analysis of the different phenotypic expressions and sex of the transmitting parent failed to provide evidence of significant group differences. We found no significant differences in the age at diagnosis either. However, the maternally transmitted offspring showed a significantly earlier age at onset. This points to a parent of origin effect on the putative TS gene that could be explained by meiotic events or even intrauterine environmental influences. These findings may help explain the hitherto conflicting reports about the nature of genetic transmission in TS, and suggest a need to re-examine family data separately for maternally and paternally transmitted cases, taking into account the possible role of imprinting.

  15. Rapid Diagnosis of Imprinting Disorders Involving Copy Number Variation and Uniparental Disomy Using Genome-Wide SNP Microarrays.

    Science.gov (United States)

    Liu, Weiqiang; Zhang, Rui; Wei, Jun; Zhang, Huimin; Yu, Guojiu; Li, Zhihua; Chen, Min; Sun, Xiaofang

    2015-01-01

    Imprinting disorders, such as Beckwith-Wiedemann syndrome (BWS), Prader-Willi syndrome (PWS) and Angelman syndrome (AS), can be detected via methylation analysis, methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA), or other methods. In this study, we applied single nucleotide polymorphism (SNP)-based chromosomal microarray analysis to detect copy number variations (CNVs) and uniparental disomy (UPD) events in patients with suspected imprinting disorders. Of 4 patients, 2 had a 5.25-Mb microdeletion in the 15q11.2q13.2 region, 1 had a 38.4-Mb mosaic UPD in the 11p15.4 region, and 1 had a 60-Mb detectable UPD between regions 14q13.2 and 14q32.13. Although the 14q32.2 region was classified as normal by SNP array for the 14q13 UPD patient, it turned out to be a heterodisomic UPD by short tandem repeat marker analysis. MS-MLPA analysis was performed to validate the variations. In conclusion, SNP-based microarray is an efficient alternative method for quickly and precisely diagnosing PWS, AS, BWS, and other imprinted gene-associated disorders when considering aberrations due to CNVs and most types of UPD.

  16. Imprinting disorders

    DEFF Research Database (Denmark)

    Eggermann, Thomas; Perez de Nanclares, Guiomar; Maher, Eamonn R

    2015-01-01

    Congenital imprinting disorders (IDs) are characterised by molecular changes affecting imprinted chromosomal regions and genes, i.e. genes that are expressed in a parent-of-origin specific manner. Recent years have seen a great expansion in the range of alterations in regulation, dosage or DNA...... impacts upon growth, development and metabolism. Thus, detailed and systematic analysis of IDs can not only identify unifying principles of molecular epigenetics in health and disease, but also support personalisation of diagnosis and management for individual patients and families....

  17. Mosaicism for genome-wide paternal uniparental disomy with features of multiple imprinting disorders: diagnostic and management issues.

    Science.gov (United States)

    Inbar-Feigenberg, Michal; Choufani, Sanaa; Cytrynbaum, Cheryl; Chen, Yi-An; Steele, Leslie; Shuman, Cheryl; Ray, Peter N; Weksberg, Rosanna

    2013-01-01

    Mosaicism for genome-wide paternal uniparental disomy (UPD) has been reported in only seven live born individuals to date. Clinical presentation includes manifestations of multiple paternal UPD syndromes with high variability, likely due to the variable levels of mosaicism in different somatic tissues. We report an eighth case in a female patient with mosaicism for genome-wide paternal UPD which highlights the complex clinical presentation. Our patient had features of Beckwith-Wiedemann syndrome (BWS), Angelman syndrome, and congenital hyperinsulinism. The clinical findings included prematurity, organomegaly, hemihyperplasia, developmental delay, benign tumors, and cystic lesions. The diagnosis in our patient was established utilizing microarray-based genome-wide DNA methylation analysis performed on leukocyte DNA. Targeted multiplex ligation-dependent probe amplification (MLPA) analysis of chromosome regions 11p15 and 15q13 confirmed mosaicism for paternal UPD at these genomic regions. This case represents the first report of microarray-based genome-wide DNA methylation analysis in the diagnosis of genome-wide paternal UPD. The application of microarray-based genome-wide DNA methylation analysis on selected individuals with complex clinical presentations could be a valuable diagnostic tool to improve the detection rate of mosaic genome-wide paternal UPD. This approach, which screens many loci simultaneously, is more cost-effective and less labor-intensive than performing multiple targeted DNA methylation-based assays. Identification of individuals with mosaicism for genome-wide paternal UPD is an important goal as it confers a low recurrence risk for the family and identifies individuals who require surveillance due to increased tumor risk.

  18. The possible role of genomic imprinting at HLA-DQ/DR region in the pathogenesis of insulin-dependent diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, T.; Nemoto, M.; Nishimura, R. [Univ. School of Medicine, Tokyo (Japan)] [and others

    1994-09-01

    Insulin-dependent diabetes mellitus (IDDM) is an autoimmune endocrinopathy that often develops with anti glutamic acid decarboxylase autoantibody (GAD-Ab). Accumulated data indicate that specific alleles with HLA-DQA1{sup *}0301 strongly associate with IDDM so that its susceptible gene is localized at HLA class II DQ/DR region. The mode of transmission, however, remains still unclear. To investigate the possibility of involvement of genomic imprinting at the susceptible gene in IDDM, we conducted pedigree analysis of 16 IDDM probands who are positive for GAD-Ab and their first-degree relatives consisting of 14 mothers, 11 fathers and 11 sibs. The GAD-Ab was measured with RIA (cut off = 5 U/ml), and genotypes of DQA1 and DRB1 loci were determined with PCR-RFLP method. Of the observed 16 families, one had an affected brother who developed IDDM and was positive for GAD-Ab (144 U/ml), but the remaining 15 were simplex families. Except for the affected brother, all relatives appeared to be negative for GAD-Ab. DQA1 genotyping showed that 11 probands were homozygotes of high-risk DQA1{sup *}0301, but the five probands were heterozygous with DQA1{sup *}0301/X who were informative for the parental origin of DQA1{sup *}0301 allele. Pedigree analyses revealed that all DQA1{sup *}0301 alleles of the five affected heterozygotes were transmitted from their mothers. We next analyzed segregation pattern of DQA1-DRB1 haplotypes and found that the affected brother shared the same maternally transmitted allele with the proband. Further haplotype analysis indicated that the informative six unaffected sibs did not share the maternally transmitted DQA1{sup *}0301 alleles with their probands. From the exclusive association with maternally transmitted DQA{sup *}0301 alleles, we propose the hypothesis that maternal transmission of {open_quotes}affected alleles{close_quotes} are required for the development of IDDM with the mechanism of genomic imprinting at the HLA-DQ/DR region.

  19. Imprinting in Plants and Its Underlying Mechanisms

    Institute of Scientific and Technical Information of China (English)

    Hongyu Zhang; Abed Chaudhury; Xianjun Wu

    2013-01-01

    Genomic imprinting (or imprinting) refers to an epigenetic phenomenon by which the allelic expression of a gene depends on the parent of origin.It has evolved independently in placental mammals and flowering plants.In plants,imprinting is mainly found in endosperm.Recent genome-wide surveys in Arabidopsis,rice,and maize identified hundreds of imprinted genes in endosperm.Since these genes are of diverse functions,endosperm development is regulated at different regulatory levels.The imprinted expression of only a few genes is conserved between Arabidopsis and monocots,suggesting that imprinting evolved quickly during speciation.In Arabidopsis,DEMETER (DME) mediates hypomethylation in the maternal genome at numerous loci (mainly transposons and repeats) in the central cell and results in many differentially methylated regions between parental genomes in the endosperm,and subsequent imprinted expression of some genes.In addition,histone modification mediated by Polycomb group (PcG) proteins is also involved in regulating imprinting.DMEinduced hypomethylated alleles in the central cell are considered to produce small interfering RNAs (siRNAs) which are imported to the egg to reinforce DNA methylation.In parallel,the activity of DME in the vegetative cell of the male gametophyte demethylates many regions which overlap with the demethylated regions in the central cell.siRNAs from the demethylated regions are hypothesized to be also transferred into sperm to reinforce DNA methylation.Imprinting is partly the result of genome-wide epigenetic reprogramming in the central cell and vegetative cell and evolved under different selective pressures.

  20. Divergence of imprinted genes during mammalian evolution

    Directory of Open Access Journals (Sweden)

    Helms Volkhard

    2010-04-01

    Full Text Available Abstract Background In contrast to the majority of mammalian genes, imprinted genes are monoallelically expressed with the choice of the active allele depending on its parental origin. Due to their special inheritance patterns, maternally and paternally expressed genes might be under different evolutionary pressure. Here, we aimed at assessing the evolutionary history of imprinted genes. Results In this study, we investigated the conservation of imprinted genes in vertebrate genomes and their exposition to natural selection. In a genome-wide comparison, orthologs of imprinted genes show a stronger divergence on cDNA and protein level in mammals. This pattern is most pronounced for maternally expressed genes in rodents in comparison to their non-rodent orthologs. The divergence is not attributable to increased mutation of CpG positions. It is contrasted by strong conservation of paternally expressed genes in mouse and rat. Interestingly, we found that the early divergence of imprinted genes was accompanied by an unusually strict conservation of their paralogs. Conclusions The apparent degeneration of maternally expressed genes may reflect a relaxation of selective pressure due to counteracting effects on maternal and embryonic fitness. Functional redundancy provided by the presence of highly conserved (non-imprinted paralogs may have facilitated the divergence. Moreover, intensification of imprinting in modern rodents seems to have shifted the evolutionary fate of imprinted genes towards strong purifying selection.

  1. [Imprinting genes and it's expression in Arabidopsis].

    Science.gov (United States)

    Zhang, Hong-Yu; Xu, Pei-Zhou; Yang, Hua; Wu, Xian-Jun

    2010-07-01

    Genomic imprinting refers to the phenomenon that the expression of a gene copy depends on its parent of origin. The Arabidopsis imprinted FIS (Fertilisation-independent seed) genes, mea, fis2, and fie, play essential roles in the repression of central cell and the regulation of early endosperm development. fis mutants display two phenotypes: autonomous diploid endosperm development when fertilization is absent and un-cellularised endosperm formation when fertilization occurs. The FIS Polycomb protein complex including the above three FIS proteins catalyzes histone H3 K27 tri-methylation on target loci. DME (DEMETER), a DNA glycosylase, and AtMET1 (Methyltransferase1), a DNA methyltransferase, are involved in the regulation of imprinted expression of both mea and fis2. This review summarizes the studies on the Arabidopsis imprinted FIS genes and other related genes. Recent works have shown that the insertion of transposons may affect nearby gene expression, which may be the main driving force behind the evolution of genomic imprinting. This summary covers the achievements on Arabidopsis imprinted genes will provide important information for studies on genomic imprinting in the important crops such as rice and maize.

  2. Systems biology discoveries using non-human primate pluripotent stem and germ cells: novel gene and genomic imprinting interactions as well as unique expression patterns.

    Science.gov (United States)

    Ben-Yehudah, Ahmi; Easley, Charles A; Hermann, Brian P; Castro, Carlos; Simerly, Calvin; Orwig, Kyle E; Mitalipov, Shoukhrat; Schatten, Gerald

    2010-08-05

    The study of pluripotent stem cells has generated much interest in both biology and medicine. Understanding the fundamentals of biological decisions, including what permits a cell to maintain pluripotency, that is, its ability to self-renew and thereby remain immortal, or to differentiate into multiple types of cells, is of profound importance. For clinical applications, pluripotent cells, including both embryonic stem cells and adult stem cells, have been proposed for cell replacement therapy for a number of human diseases and disorders, including Alzheimer's, Parkinson's, spinal cord injury and diabetes. One challenge in their usage for such therapies is understanding the mechanisms that allow the maintenance of pluripotency and controlling the specific differentiation into required functional target cells. Because of regulatory restrictions and biological feasibilities, there are many crucial investigations that are just impossible to perform using pluripotent stem cells (PSCs) from humans (for example, direct comparisons among panels of inbred embryonic stem cells from prime embryos obtained from pedigreed and fertile donors; genomic analysis of parent versus progeny PSCs and their identical differentiated tissues; intraspecific chimera analyses for pluripotency testing; and so on). However, PSCs from nonhuman primates are being investigated to bridge these knowledge gaps between discoveries in mice and vital information necessary for appropriate clinical evaluations. In this review, we consider the mRNAs and novel genes with unique expression and imprinting patterns that were discovered using systems biology approaches with primate pluripotent stem and germ cells.

  3. Glial cell line-derived neurotrophic factor alters the growth characteristics and genomic imprinting of mouse multipotent adult germline stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yoon Hee [Department of Bioscience and Biotechnology, Bio-Organ Research Center/Animal Resources Research Center, Konkuk University, Hwayang-dong, Gwangjin-Gu, Seoul 143 701 (Korea, Republic of); Gupta, Mukesh Kumar, E-mail: goops@konkuk.ac.kr [Department of Animal Biotechnology, Bio-Organ Research Center/Animal Resources Research Center, Konkuk University, Hwayang-dong, Gwangjin-Gu, Seoul 143 701 (Korea, Republic of); Oh, Shin Hye [Department of Bioscience and Biotechnology, Bio-Organ Research Center/Animal Resources Research Center, Konkuk University, Hwayang-dong, Gwangjin-Gu, Seoul 143 701 (Korea, Republic of); Uhm, Sang Jun [Department of Animal Biotechnology, Bio-Organ Research Center/Animal Resources Research Center, Konkuk University, Hwayang-dong, Gwangjin-Gu, Seoul 143 701 (Korea, Republic of); Lee, Hoon Taek, E-mail: htl3675@konkuk.ac.kr [Department of Bioscience and Biotechnology, Bio-Organ Research Center/Animal Resources Research Center, Konkuk University, Hwayang-dong, Gwangjin-Gu, Seoul 143 701 (Korea, Republic of); Department of Animal Biotechnology, Bio-Organ Research Center/Animal Resources Research Center, Konkuk University, Hwayang-dong, Gwangjin-Gu, Seoul 143 701 (Korea, Republic of)

    2010-03-10

    This study evaluated the essentiality of glial cell line-derived neurotrophic factor (GDNF) for in vitro culture of established mouse multipotent adult germline stem (maGS) cell lines by culturing them in the presence of GDNF, leukemia inhibitory factor (LIF) or both. We show that, in the absence of LIF, GDNF slows the proliferation of maGS cells and result in smaller sized colonies without any change in distribution of cells to different cell-cycle stages, expression of pluripotency genes and in vitro differentiation potential. Furthermore, in the absence of LIF, GDNF increased the expression of male germ-line genes and repopulated the empty seminiferous tubule of W/W{sup v} mutant mouse without the formation of teratoma. GDNF also altered the genomic imprinting of Igf2, Peg1, and H19 genes but had no effect on DNA methylation of Oct4, Nanog and Stra8 genes. However, these effects of GDNF were masked in the presence of LIF. GDNF also did not interfere with the multipotency of maGS cells if they are cultured in the presence of LIF. In conclusion, our results suggest that, in the absence of LIF, GDNF alters the growth characteristics of maGS cells and partially impart them some of the germline stem (GS) cell-like characteristics.

  4. Modulation of imprinted gene expression following superovulation.

    Science.gov (United States)

    Fortier, Amanda L; McGraw, Serge; Lopes, Flavia L; Niles, Kirsten M; Landry, Mylène; Trasler, Jacquetta M

    2014-05-05

    Although assisted reproductive technologies increase the risk of low birth weight and genomic imprinting disorders, the precise underlying causes remain unclear. Using a mouse model, we previously showed that superovulation alters the expression of imprinted genes in the placenta at 9.5days (E9.5) of gestation. Here, we investigate whether effects of superovulation on genomic imprinting persisted at later stages of development and assess the surviving fetuses for growth and morphological abnormalities. Superovulation, followed by embryo transfer at E3.5, as compared to spontaneous ovulation (controls), resulted in embryos of normal size and weight at 14.5 and 18.5days of gestation. The normal monoallelic expression of the imprinted genes H19, Snrpn and Kcnq1ot1 was unaffected in either the placentae or the embryos from the superovulated females at E14.5 or E18.5. However, for the paternally expressed imprinted gene Igf2, superovulation generated placentae with reduced production of the mature protein at E9.5 and significantly more variable mRNA levels at E14.5. We propose that superovulation results in the ovulation of abnormal oocytes with altered expression of imprinted genes, but that the coregulated genes of the imprinted gene network result in modulated expression. Copyright © 2014. Published by Elsevier Ireland Ltd.

  5. Human imprinted retrogenes exhibit non-canonical imprint chromatin signatures and reside in non-imprinted host genes

    Science.gov (United States)

    Monk, David; Arnaud, Philippe; Frost, Jennifer M.; Wood, Andrew J.; Cowley, Michael; Martin-Trujillo, Alejandro; Guillaumet-Adkins, Amy; Iglesias Platas, Isabel; Camprubi, Cristina; Bourc’his, Deborah; Feil, Robert; Moore, Gudrun E.; Oakey, Rebecca J.

    2011-01-01

    Imprinted retrotransposed genes share a common genomic organization including a promoter-associated differentially methylated region (DMR) and a position within the intron of a multi-exonic ‘host’ gene. In the mouse, at least one transcript of the host gene is also subject to genomic imprinting. Human retrogene orthologues are imprinted and we reveal that human host genes are not imprinted. This coincides with genomic rearrangements that occurred during primate evolution, which increase the separation between the retrogene DMRs and the host genes. To address the mechanisms governing imprinted retrogene expression, histone modifications were assayed at the DMRs. For the mouse retrogenes, the active mark H3K4me2 was associated with the unmethylated paternal allele, while the methylated maternal allele was enriched in repressive marks including H3K9me3 and H4K20me3. Two human retrogenes showed monoallelic enrichment of active, but not of repressive marks suggesting a partial uncoupling of the relationship between DNA methylation and repressive histone methylation, possibly due to the smaller size and lower CpG density of these DMRs. Finally, we show that the genes immediately flanking the host genes in mouse and human are biallelically expressed in a range of tissues, suggesting that these loci are distinct from large imprinted clusters. PMID:21300645

  6. MEDEA takes control of its own imprinting.

    Science.gov (United States)

    Arnaud, Philippe; Feil, Robert

    2006-02-10

    Genomic imprinting is an essential epigenetic process that controls the size of seeds in flowering plants. In Arabidopsis, DEMETER activates the maternal copy of the imprinted MEDEA Polycomb gene. In this issue of Cell, Gehring et al. (2006) demonstrate that this activation involves DNA demethylation of MEDEA by DEMETER. Remarkably, they also find that silencing of the paternal MEDEA allele is independent of DNA methylation and is controlled by maternal expression of MEDEA itself.

  7. The evolution of imprinting: chromosomal mapping of orthologues of mammalian imprinted domains in monotreme and marsupial mammals

    Directory of Open Access Journals (Sweden)

    Dunham Ian

    2007-09-01

    Full Text Available Abstract Background The evolution of genomic imprinting, the parental-origin specific expression of genes, is the subject of much debate. There are several theories to account for how the mechanism evolved including the hypothesis that it was driven by the evolution of X-inactivation, or that it arose from an ancestrally imprinted chromosome. Results Here we demonstrate that mammalian orthologues of imprinted genes are dispersed amongst autosomes in both monotreme and marsupial karyotypes. Conclusion These data, along with the similar distribution seen in birds, suggest that imprinted genes were not located on an ancestrally imprinted chromosome or associated with a sex chromosome. Our results suggest imprinting evolution was a stepwise, adaptive process, with each gene/cluster independently becoming imprinted as the need arose.

  8. Positive darwinian selection at the imprinted MEDEA locus in plants.

    Science.gov (United States)

    Spillane, Charles; Schmid, Karl J; Laoueillé-Duprat, Sylvia; Pien, Stéphane; Escobar-Restrepo, Juan-Miguel; Baroux, Célia; Gagliardini, Valeria; Page, Damian R; Wolfe, Kenneth H; Grossniklaus, Ueli

    2007-07-19

    In mammals and seed plants, a subset of genes is regulated by genomic imprinting where an allele's activity depends on its parental origin. The parental conflict theory suggests that genomic imprinting evolved after the emergence of an embryo-nourishing tissue (placenta and endosperm), resulting in an intragenomic parental conflict over the allocation of nutrients from mother to offspring. It was predicted that imprinted genes, which arose through antagonistic co-evolution driven by a parental conflict, should be subject to positive darwinian selection. Here we show that the imprinted plant gene MEDEA (MEA), which is essential for seed development, originated during a whole-genome duplication 35 to 85 million years ago. After duplication, MEA underwent positive darwinian selection consistent with neo-functionalization and the parental conflict theory. MEA continues to evolve rapidly in the out-crossing species Arabidopsis lyrata but not in the self-fertilizing species Arabidopsis thaliana, where parental conflicts are reduced. The paralogue of MEA, SWINGER (SWN; also called EZA1), is not imprinted and evolved under strong purifying selection because it probably retained the ancestral function of the common precursor gene. The evolution of MEA suggests a late origin of genomic imprinting within the Brassicaceae, whereas imprinting is thought to have originated early within the mammalian lineage.

  9. Expression and imprinting of insulin-like growth factor II (IGF2) and H19 genes in uterine leiomyomas

    DEFF Research Database (Denmark)

    Rainho, C A; Pontes, A; Rogatto, S R

    1999-01-01

    Genomic imprinting is defined as a gamete of origin-specific epigenetic modification of DNA leading to differential gene expression in the zygote. Several imprinted genes have been identified and some of them are associated with tumor development. We investigated the expression and the imprinting...

  10. Functional mapping imprinted quantitative trait loci underlying developmental characteristics

    Directory of Open Access Journals (Sweden)

    Li Gengxin

    2008-03-01

    Full Text Available Abstract Background Genomic imprinting, a phenomenon referring to nonequivalent expression of alleles depending on their parental origins, has been widely observed in nature. It has been shown recently that the epigenetic modification of an imprinted gene can be detected through a genetic mapping approach. Such an approach is developed based on traditional quantitative trait loci (QTL mapping focusing on single trait analysis. Recent studies have shown that most imprinted genes in mammals play an important role in controlling embryonic growth and post-natal development. For a developmental character such as growth, current approach is less efficient in dissecting the dynamic genetic effect of imprinted genes during individual ontology. Results Functional mapping has been emerging as a powerful framework for mapping quantitative trait loci underlying complex traits showing developmental characteristics. To understand the genetic architecture of dynamic imprinted traits, we propose a mapping strategy by integrating the functional mapping approach with genomic imprinting. We demonstrate the approach through mapping imprinted QTL controlling growth trajectories in an inbred F2 population. The statistical behavior of the approach is shown through simulation studies, in which the parameters can be estimated with reasonable precision under different simulation scenarios. The utility of the approach is illustrated through real data analysis in an F2 family derived from LG/J and SM/J mouse stains. Three maternally imprinted QTLs are identified as regulating the growth trajectory of mouse body weight. Conclusion The functional iQTL mapping approach developed here provides a quantitative and testable framework for assessing the interplay between imprinted genes and a developmental process, and will have important implications for elucidating the genetic architecture of imprinted traits.

  11. Human imprinting anomalies in fetal and childhood growth disorders: clinical implications and molecular mechanisms.

    Science.gov (United States)

    Azzi, Salah; Brioude, Fréderic; Le Bouc, Yves; Netchine, Irène

    2014-01-01

    Genomic imprinting is among the most important epigenetic mechanisms whereby expression of a subset of genes is restricted to a single parental allele. Loss of imprinting (LOI) through hypo or hyper methylation is involved in various human syndromes. These LOI occur early during development and usually impair growth. Some imprinting syndromes are the consequences of genetic anomalies, such as uniparental disomies (UPD) or copy number variations (deletion or duplications) involving the imprinted domains; others are due to LOI at the imprinting control regions (ICR) regulating each domain. Imprinting disorders are phenotypically heterogeneous, although some share various common clinical features such that diagnosis may be difficult. Multilocus imprinting defects associated with several syndromes have been increasingly reported in recent years, although there are no obvious clinical differences between monolocus and multilocus LOI patients. Subsequently, some rare mutations of transacting factors have been identified in patients with multilocus imprinting defects but they do not explain the majority of the cases; this therefore implies that other factors are involved. By contrast, no mutation of a transacting factor has yet been identified in monolocus LOI. The effect of the environment on the regulation of imprinting is clearly illustrated by studies of assisted reproductive technology (ART). The regulation of imprinting is complex and involves a huge range of genetic and environmental factors; the identification of these factors will undoubtedly help to elucidate the regulation of imprinting and contribute to the understanding of imprinting disorders. This would be beneficial for diagnostics, clinical follow up and the development of treatment guidelines.

  12. Short interspersed element (SINE) depletion and long interspersed element (LINE) abundance are not features universally required for imprinting.

    Science.gov (United States)

    Cowley, Michael; de Burca, Anna; McCole, Ruth B; Chahal, Mandeep; Saadat, Ghazal; Oakey, Rebecca J; Schulz, Reiner

    2011-04-20

    Genomic imprinting is a form of gene dosage regulation in which a gene is expressed from only one of the alleles, in a manner dependent on the parent of origin. The mechanisms governing imprinted gene expression have been investigated in detail and have greatly contributed to our understanding of genome regulation in general. Both DNA sequence features, such as CpG islands, and epigenetic features, such as DNA methylation and non-coding RNAs, play important roles in achieving imprinted expression. However, the relative importance of these factors varies depending on the locus in question. Defining the minimal features that are absolutely required for imprinting would help us to understand how imprinting has evolved mechanistically. Imprinted retrogenes are a subset of imprinted loci that are relatively simple in their genomic organisation, being distinct from large imprinting clusters, and have the potential to be used as tools to address this question. Here, we compare the repeat element content of imprinted retrogene loci with non-imprinted controls that have a similar locus organisation. We observe no significant differences that are conserved between mouse and human, suggesting that the paucity of SINEs and relative abundance of LINEs at imprinted loci reported by others is not a sequence feature universally required for imprinting.

  13. Short interspersed element (SINE depletion and long interspersed element (LINE abundance are not features universally required for imprinting.

    Directory of Open Access Journals (Sweden)

    Michael Cowley

    Full Text Available Genomic imprinting is a form of gene dosage regulation in which a gene is expressed from only one of the alleles, in a manner dependent on the parent of origin. The mechanisms governing imprinted gene expression have been investigated in detail and have greatly contributed to our understanding of genome regulation in general. Both DNA sequence features, such as CpG islands, and epigenetic features, such as DNA methylation and non-coding RNAs, play important roles in achieving imprinted expression. However, the relative importance of these factors varies depending on the locus in question. Defining the minimal features that are absolutely required for imprinting would help us to understand how imprinting has evolved mechanistically. Imprinted retrogenes are a subset of imprinted loci that are relatively simple in their genomic organisation, being distinct from large imprinting clusters, and have the potential to be used as tools to address this question. Here, we compare the repeat element content of imprinted retrogene loci with non-imprinted controls that have a similar locus organisation. We observe no significant differences that are conserved between mouse and human, suggesting that the paucity of SINEs and relative abundance of LINEs at imprinted loci reported by others is not a sequence feature universally required for imprinting.

  14. Changes in Parthenogenetic Imprinting Patterns during Reprogramming by Cell Fusion.

    Directory of Open Access Journals (Sweden)

    Hyun Sik Jang

    Full Text Available Differentiated somatic cells can be reprogrammed into the pluripotent state by cell-cell fusion. In the pluripotent state, reprogrammed cells may then self-renew and differentiate into all three germ layers. Fusion-induced reprogramming also epigenetically modifies the somatic cell genome through DNA demethylation, X chromosome reactivation, and histone modification. In this study, we investigated whether fusion with embryonic stem cells (ESCs also reprograms genomic imprinting patterns in somatic cells. In particular, we examined imprinting changes in parthenogenetic neural stem cells fused with biparental ESCs, as well as in biparental neural stem cells fused with parthenogenetic ESCs. The resulting hybrid cells expressed the pluripotency markers Oct4 and Nanog. In addition, methylation of several imprinted genes except Peg3 was comparable between hybrid cells and ESCs. This finding indicates that reprogramming by cell fusion does not necessarily reverse the status of all imprinted genes to the state of pluripotent fusion partner.

  15. [Neurobiology of imprinting].

    Science.gov (United States)

    Ohki-Hamazaki, Hiroko

    2012-06-01

    Imprinting is an example of learning and memory acquisition in infancy. In the case of precocial birds, such as geese, ducks, and chickens, the baby birds learn the characteristics of the first moving object that they see within a critical period, and they imprint on it and follow it around. We analyzed the neural basis of this behavior in order to understand the neural mechanism of learning and memory in infancy. Information pertaining to a visual imprinting stimulus is recognized and processed in the visual Wulst, a region that corresponds to the mammalian visual cortex. It is then transmitted to the posterior region of the telencephalon, followed by the core region of the hyperpallium densocellulare (HDCo), periventricular region of the hyperpallium densocellulare (HDPe), and finally, the intermediate medial mesopallium (IMM), a region similar to the mammalian association cortex. Memory is stored in the IMM. After imprint training, plastic changes are observed in the visual Wulst as well as in the neurons of this circuit. HDCo cells, located at the center of this circuit, express N-methyl-D-aspartate (NMDA) receptors containing the NMDA receptor (NR) 2B subunit; the expression of this receptor increased after the imprint training. Inhibition of this receptor in the cells of the HDCo region leads to failure of imprinting and inactivation of this circuit. Thus, NMDA receptors bearing the NR2B subunit play a critical role in plastic changes in this circuit and in induction of imprinting.

  16. Allelic expression of mammalian imprinted genes in a matrotrophic lizard, Pseudemoia entrecasteauxii.

    Science.gov (United States)

    Griffith, Oliver W; Brandley, Matthew C; Belov, Katherine; Thompson, Michael B

    2016-03-01

    Genomic imprinting is a process that results in the differential expression of genes depending on their parent of origin. It occurs in both plants and live-bearing mammals, with imprinted genes typically regulating the ability of an embryo to manipulate the maternal provision of nutrients. Genomic imprinting increases the potential for selection to act separately on paternally and maternally expressed genes, which increases the number of opportunities that selection can facilitate embryonic control over maternal nutrient provision. By looking for imprinting in an independent matrotrophic lineage, the viviparous lizard Pseudemoia entrecasteauxii (Scincidae), we test the hypothesis that genomic imprinting facilitates the evolution of substantial placental nutrient transport to embryos (matrotrophy). We sequenced transcriptomes from the embryonic component of lizard placentae to determine whether there are parent-of-origin differences in expression of genes that are imprinted in mammals. Of these genes, 19 had sufficiently high expression in the lizard to identify polymorphisms in transcribed sequences. We identified bi-allelic expression in 17 genes (including insulin-like growth factor 2), indicating that neither allele was imprinted. These data suggest that either genomic imprinting has not evolved in this matrotrophic skink or, if it has, it has evolved in different genes to mammals. We outline how these hypotheses can be tested. This study highlights important differences between mammalian and reptile pregnancy and the absence of any shared imprinting genes reflects fundamental differences in the way that pregnancy has evolved in these two lineages.

  17. Molecularly Imprinted Biodegradable Nanoparticles

    Science.gov (United States)

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization.

  18. Molecularly Imprinted Biodegradable Nanoparticles

    Science.gov (United States)

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization. PMID:28071745

  19. Imprinting in plants as a mechanism to generate seed phenotypic diversity

    Directory of Open Access Journals (Sweden)

    A Mark eSettles

    2015-01-01

    Full Text Available Normal plant development requires epigenetic regulation to enforce changes in developmental fate. Genomic imprinting is a type of epigenetic regulation in which identical alleles of genes are expressed in a parent-of-origin dependent manner. Deep sequencing of transcriptomes has identified hundreds of imprinted genes with scarce evidence for the developmental importance of individual imprinted loci. Imprinting is regulated through global DNA demethylation in the central cell prior to fertilization and directed repression of individual loci with the Polycomb Repressive Complex 2 (PRC2. There is significant evidence for transposable elements and repeat sequences near genes acting as cis-elements to determine imprinting status of a gene, implying that imprinted gene expression patterns may evolve randomly and at high frequency. Detailed genetic analysis of a few imprinted loci suggests an imprinted pattern of gene expression is often dispensable for seed development. Few genes show conserved imprinted expression within or between plant species. These data are not fully explained by current models for the evolution of imprinting in plant seeds. We suggest that imprinting may have evolved to provide a mechanism for rapid neofunctionalization of genes during seed development to increase phenotypic diversity of seeds.

  20. A survey of assisted reproductive technology births and imprinting disorders.

    Science.gov (United States)

    Bowdin, Sarah; Allen, Cathy; Kirby, Gail; Brueton, Louise; Afnan, Masoud; Barratt, Christopher; Kirkman-Brown, Jackson; Harrison, Robert; Maher, Eamonn R; Reardon, William

    2007-12-01

    Genomic imprinting is an epigenetic process in which allele-specific gene expression is dependent on the parental inheritance. Although only a minority of human genes are imprinted, those that have been identified to date have been preferentially implicated in prenatal growth and neurodevelopment. Mutations or epimutations in imprinted genes or imprinting control centres are associated with imprinting disorders such as Angelman syndrome (AS) and Beckwith-Wiedemann syndrome (BWS). Recently, an increased frequency of assisted reproductive technology (ART) conceptions has been reported in children with BWS and AS. However, the risk of imprinting disorders in ART children is unknown. We undertook a survey of 2492 children born after ART in the Republic of Ireland and Central England with the aim of detecting cases (both clinically diagnosed and previously unrecognized) of BWS and AS in this cohort. The response rate to an initial questionnaire was 61%, corresponding to data for 1524 children. After evaluation of the questionnaire, 70 children were invited for a detailed clinical assessment, and 47 accepted (response rate of 67%). In this entire cohort, we detected one case of BWS and no cases of AS. We did not find evidence that there exists a significant group of ART children with unrecognized milder forms of AS or BWS. Although previous studies have suggested an increased relative risk of BWS and AS after ART, our findings suggest that the absolute risk of imprinting disorders in children conceived by ART is small (<1%). Precise risk estimates of risk are difficult to define because of the rarity of the conditions and incomplete response rates to the questionnaire and clinical examination invitations. Hence further investigations are indicated to (i) refine the absolute and relative risks of imprinting disorders after ART and (ii) ensure that changes in ART protocols are not associated with increased frequencies of epigenetic changes and imprinting disorders in

  1. Thyroid hormone determines the start of the sensitive period of imprinting and primes later learning.

    Science.gov (United States)

    Yamaguchi, Shinji; Aoki, Naoya; Kitajima, Takaaki; Iikubo, Eiji; Katagiri, Sachiko; Matsushima, Toshiya; Homma, Koichi J

    2012-01-01

    Filial imprinting in precocial birds is the process of forming a social attachment during a sensitive or critical period, restricted to the first few days after hatching. Imprinting is considered to be part of early learning to aid the survival of juveniles by securing maternal care. Here we show that the thyroid hormone 3,5,3'-triiodothyronine (T(3)) determines the start of the sensitive period. Imprinting training in chicks causes rapid inflow of T(3), converted from circulating plasma thyroxine by Dio2, type 2 iodothyronine deiodinase, in brain vascular endothelial cells. The T(3) thus initiates and extends the sensitive period to last more than 1 week via non-genomic mechanisms and primes subsequent learning. Even in non-imprinted chicks whose sensitive period has ended, exogenous T(3) enables imprinting. Our findings indicate that T(3) determines the start of the sensitive period for imprinting and has a critical role in later learning.

  2. Molecularly Imprinted Membranes

    Directory of Open Access Journals (Sweden)

    Fabrizio Caldera

    2012-07-01

    Full Text Available Although the roots of molecularly imprinted polymers lie in the beginning of 1930s in the past century, they have had an exponential growth only 40–50 years later by the works of Wulff and especially by Mosbach. More recently, it was also proved that molecular imprinted membranes (i.e., polymer thin films that show recognition properties at molecular level of the template molecule are used in their formation. Different procedures and potential application in separation processes and catalysis are reported. The influences of different parameters on the discrimination abilities are also discussed.

  3. Distinguishing epigenetic marks of developmental and imprinting regulation

    Directory of Open Access Journals (Sweden)

    McEwen Kirsten R

    2010-01-01

    Full Text Available Abstract Background The field of epigenetics is developing rapidly, however we are only beginning to comprehend the complexity of its influence on gene regulation. Using genomic imprinting as a model we examine epigenetic profiles associated with different forms of gene regulation. Imprinting refers to the expression of a gene from only one of the chromosome homologues in a parental-origin-specific manner. This is dependent on heritable germline epigenetic control at a cis-acting imprinting control region that influences local epigenetic states. Epigenetic modifications associated with imprinting regulation can be compared to those associated with the more canonical developmental regulation, important for processes such as differentiation and tissue specificity. Here we test the hypothesis that these two mechanisms are associated with different histone modification enrichment patterns. Results Using high-throughput data extraction with subsequent analysis, we have found that particular histone modifications are more likely to be associated with either imprinting repression or developmental repression of imprinted genes. H3K9me3 and H4K20me3 are together enriched at imprinted genes with differentially methylated promoters and do not show a correlation with developmental regulation. H3K27me3 and H3K4me3, however, are more often associated with developmental regulation. We find that imprinted genes are subject to developmental regulation through bivalency with H3K4me3 and H3K27me3 enrichment on the same allele. Furthermore, a specific tri-mark signature comprising H3K4me3, H3K9me3 and H4K20me3 has been identified at all imprinting control regions. Conclusion A large amount of data is produced from whole-genome expression and epigenetic profiling studies of cellular material. We have shown that such publicly available data can be mined and analysed in order to generate novel findings for categories of genes or regulatory elements. Comparing two

  4. A role for chromatin topology in imprinted domain regulation.

    Science.gov (United States)

    MacDonald, William A; Sachani, Saqib S; White, Carlee R; Mann, Mellissa R W

    2016-02-01

    Recently, many advancements in genome-wide chromatin topology and nuclear architecture have unveiled the complex and hidden world of the nucleus, where chromatin is organized into discrete neighbourhoods with coordinated gene expression. This includes the active and inactive X chromosomes. Using X chromosome inactivation as a working model, we utilized publicly available datasets together with a literature review to gain insight into topologically associated domains, lamin-associated domains, nucleolar-associating domains, scaffold/matrix attachment regions, and nucleoporin-associated chromatin and their role in regulating monoallelic expression. Furthermore, we comprehensively review for the first time the role of chromatin topology and nuclear architecture in the regulation of genomic imprinting. We propose that chromatin topology and nuclear architecture are important regulatory mechanisms for directing gene expression within imprinted domains. Furthermore, we predict that dynamic changes in chromatin topology and nuclear architecture play roles in tissue-specific imprint domain regulation during early development and differentiation.

  5. Human imprinting disorders: Principles, practice, problems and progress.

    Science.gov (United States)

    Mackay, Deborah J G; Temple, I Karen

    2017-11-01

    Epigenetic regulation orchestrates gene expression with exquisite precision, over a huge dynamic range and across developmental space and time, permitting genomically-homogeneous humans to develop and adapt to their surroundings. Every generation, these epigenetic marks are re-set twice: in the germline, to enable differentiation of sperm and eggs, and at fertilisation, to create the totipotent zygote that then begins growth and differentiation into a new human. A small group of genes evades the second, zygotic wave of epigenetic reprogramming, and these genes retain an epigenetic 'imprint' of the parent from whom they were inherited. Imprinted genes are (as a general rule) expressed from one parental allele only. Some imprinted genes are critical regulators of growth and development, and thus disruption of their normal monoallelic expression causes congenital imprinting disorders, with clinical features impacting growth, development, behaviour and metabolism. Imprinting disorders as a group have characteristics that challenge diagnosis and management, including clinical and molecular heterogeneity, overlapping clinical features, somatic mosaicism, and multi-locus involvement. New insights into the biology and epigenomics of the early embryo offers new clues about the origin and importance of imprinting disorders. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Variable allelic expression of imprinted genes in human pluripotent stem cells during differentiation into specialized cell types in vitro.

    Science.gov (United States)

    Park, Sang-Wook; Kim, Jihoon; Park, Jong-Lyul; Ko, Ji-Yun; Im, Ilkyun; Do, Hyo-Sang; Kim, Hyemin; Tran, Ngoc-Tung; Lee, Sang-Hun; Kim, Yong Sung; Cho, Yee Sook; Lee, Dong Ryul; Han, Yong-Mahn

    2014-04-01

    Genomic imprinting is an epigenetic phenomenon by which a subset of genes is asymmetrically expressed in a parent-of-origin manner. However, little is known regarding the epigenetic behaviors of imprinted genes during human development. Here, we show dynamic epigenetic changes in imprinted genes in hESCs during in vitro differentiation into specialized cell types. Out of 9 imprinted genes with single nucleotide polymorphisms, mono-allelic expression for three imprinted genes (H19, KCNQ1OT1, and IPW), and bi- or partial-allelic expression for three imprinted genes (OSBPL5, PPP1R9A, and RTL1) were stably retained in H9-hESCs throughout differentiation, representing imprinting stability. Three imprinted genes (KCNK9, ATP10A, and SLC22A3) showed a loss and a gain of imprinting in a lineage-specific manner during differentiation. Changes in allelic expression of imprinted genes were observed in another hESC line during in vitro differentiation. These findings indicate that the allelic expression of imprinted genes may be vulnerable in a lineage-specific manner in human pluripotent stem cells during differentiation.

  7. Solvent Immersion Imprint Lithography

    Energy Technology Data Exchange (ETDEWEB)

    Vasdekis, Andreas E.; Wilkins, Michael J.; Grate, Jay W.; Kelly, Ryan T.; Konopka, Allan; Xantheas, Sotiris S.; Chang, M. T.

    2014-06-21

    The mechanism of polymer disolution was explored for polymer microsystem prototyping, including microfluidics and optofluidics. Polymer films are immersed in a solvent, imprinted and finally brought into contact with a non-modified surface to permanently bond. The underlying polymer-solvent interactions were experimentally and theoretically investigated, and enabled rapid polymer microsystem prototyping. During imprinting, small molecule integration in the molded surfaces was feasible, a principle applied to oxygen sensing. Polystyrene (PS) was employed for microbiological studies at extreme environmental conditions. The thermophile anaerobe Clostridium Thermocellum was grown in PS pore-scale micromodels, revealing a double mean generation lifetime than under ideal culture conditions. Microsystem prototyping through directed polymer dissolution is simple and accessible, while simultaneous patterning, bonding, and surface/volume functionalization are possible in less than one minute.

  8. MicroRNAs 296 and 298 are imprinted and part of the GNAS/Gnas cluster and miR-296 targets IKBKE and Tmed9

    OpenAIRE

    2012-01-01

    Genomic imprinting is the phenomenon whereby a subset of genes is differentially expressed according to parental origin. Imprinted genes tend to occur in clusters, and microRNAs are associated with the majority of well-defined clusters of imprinted genes. Here the authors show that two microRNAs, miR-296 and miR-298, are part of the imprinted Gnas/GNAS clusters in both mice and humans. Both microRNAs show imprinted expression and are expressed from the paternally derived allele, but not the m...

  9. GENE IMPRINTING: ENGRAVING THE PATHOGENESIS OF HERIDETARY DISEASES

    Directory of Open Access Journals (Sweden)

    Sandeep Satapathy

    2014-01-01

    Full Text Available Gene imprinting has conduited the scope of our understanding of phenotypic expression and its corelation with constituent genotype. It is an epigenetic process that involves DNA methylation and histone modulation to attain monoallelic gene expression without altering the genetic sequences. A distinctive model of non-mendelian genetics, imprinting extends the control over expression of traits and selection of the allele that would direct the same, in a manner decided by the parent of origin. The constitutive existence of this imprinting even after gametogenesis, throughout the somatic development extends a clue for its regulatory hold on several heridetary traits. Several heridetary diseases like Cancers, Russell-Silver syndrome, Beckwith-Wiedemann syndrome, Prader-Willi and Angelman Syndromes and Neurodegenration have shown to be a subsequent error in the genomic impriting process. So, understanding these epigenetic regulations can be a therapeutic strategy for disease modelling and especially targeting their patterns of heridetary inheritance.

  10. Categories with envelopes and imprints

    CERN Document Server

    Akbarov, Sergei

    2011-01-01

    An envelope in a category is a construction generalizing operations of "exterior completion", like completion of a locally convex space. Dually, an imprint generalizes operations of "interior enrichment", like saturation of a locally convex space. We give abstract definition for envelopes and imprints, prove existence of these objects in the categories of stereotype spaces and of stereotype algebras, and give some examples.

  11. Imprinted genes show unique patterns of sequence conservation

    Directory of Open Access Journals (Sweden)

    Helms Volkhard

    2010-11-01

    Full Text Available Abstract Background Genomic imprinting is an evolutionary conserved mechanism of epigenetic gene regulation in placental mammals that results in silencing of one of the parental alleles. In order to decipher interactions between allele-specific DNA methylation of imprinted genes and evolutionary conservation, we performed a genome-wide comparative investigation of genomic sequences and highly conserved elements of imprinted genes in human and mouse. Results Evolutionarily conserved elements in imprinted regions differ from those associated with autosomal genes in various ways. Whereas for maternally expressed genes strong divergence of protein-encoding sequences is most prominent, paternally expressed genes exhibit substantial conservation of coding and noncoding sequences. Conserved elements in imprinted regions are marked by enrichment of CpG dinucleotides and low (TpG+CpA/(2·CpG ratios indicate reduced CpG deamination. Interestingly, paternally and maternally expressed genes can be distinguished by differences in G+C and CpG contents that might be associated with unusual epigenetic features. Especially noncoding conserved elements of paternally expressed genes are exceptionally G+C and CpG rich. In addition, we confirmed a frequent occurrence of intronic CpG islands and observed a decelerated degeneration of ancient LINE-1 repeats. We also found a moderate enrichment of YY1 and CTCF binding sites in imprinted regions and identified several short sequence motifs in highly conserved elements that might act as additional regulatory elements. Conclusions We discovered several novel conserved DNA features that might be related to allele-specific DNA methylation. Our results hint at reduced CpG deamination rates in imprinted regions, which affects mostly noncoding conserved elements of paternally expressed genes. Pronounced differences between maternally and paternally expressed genes imply specific modes of evolution as a result of differences in

  12. The Role of GNAS and Other Imprinted Genes in the Development of Obesity

    Science.gov (United States)

    Weinstein, Lee S.; Xie, Tao; Qasem, Ahmed; Wang, Jie; Chen, Min

    2010-01-01

    Genomic imprinting is an epigenetic phenomenon affecting a small number of genes which leads to differential expression from the two parental alleles. Imprinted genes are known to regulate fetal growth and a ‘kinship’ or ‘parental conflict’ model predicts that paternally- and maternally-expressed imprinted genes promote and inhibit fetal growth, respectively. In this review we examine the role of imprinted genes in postnatal growth and metabolism, with an emphasis on the GNAS/Gnas locus. GNAS is a complex imprinted locus with multiple oppositely imprinted gene products, including the G protein α-subunit Gsα which is expressed primarily from the maternal allele in some tissues and the Gsα isoform XLαs which is expressed only from the paternal allele. Maternal, but not paternal, Gsα mutations lead to obesity in Albright hereditary osteodystrophy. Mouse studies show that this phenomenon is due to Gsα imprinting in the central nervous system leading to a specific defect in the ability of central melanocortins to stimulate sympathetic nervous system activity and energy expenditure. In contrast mutation of paternally-expressed XLαs leads to opposite metabolic effects in mice. While these findings conform to the ‘kinship’ model, the effects of other imprinted genes on body weight regulation do not conform to this model. PMID:19844212

  13. The evolution of the DLK1-DIO3 imprinted domain in mammals.

    Directory of Open Access Journals (Sweden)

    Carol A Edwards

    2008-06-01

    Full Text Available A comprehensive, domain-wide comparative analysis of genomic imprinting between mammals that imprint and those that do not can provide valuable information about how and why imprinting evolved. The imprinting status, DNA methylation, and genomic landscape of the Dlk1-Dio3 cluster were determined in eutherian, metatherian, and prototherian mammals including tammar wallaby and platypus. Imprinting across the whole domain evolved after the divergence of eutherian from marsupial mammals and in eutherians is under strong purifying selection. The marsupial locus at 1.6 megabases, is double that of eutherians due to the accumulation of LINE repeats. Comparative sequence analysis of the domain in seven vertebrates determined evolutionary conserved regions common to particular sub-groups and to all vertebrates. The emergence of Dlk1-Dio3 imprinting in eutherians has occurred on the maternally inherited chromosome and is associated with region-specific resistance to expansion by repetitive elements and the local introduction of noncoding transcripts including microRNAs and C/D small nucleolar RNAs. A recent mammal-specific retrotransposition event led to the formation of a completely new gene only in the eutherian domain, which may have driven imprinting at the cluster.

  14. Identification of the Imprinted KLF14 Transcription Factor Undergoing Human-Specific Accelerated Evolution

    OpenAIRE

    Layla Parker-Katiraee; Carson, Andrew R.; Takahiro Yamada; Philippe Arnaud; Robert Feil; Abu-Amero, Sayeda N.; Moore, Gudrun E; Masahiro Kaneda; Perry, George H.; Stone, Anne C.; Charles Lee; Makiko Meguro-Horike; Hiroyuki Sasaki; Keiko Kobayashi; Kazuhiko Nakabayashi

    2007-01-01

    Imprinted genes are expressed in a parent-of-origin manner and are located in clusters throughout the genome. Aberrations in the expression of imprinted genes on human Chromosome 7 have been suggested to play a role in the etiologies of Russell-Silver Syndrome and autism. We describe the imprinting of KLF14, an intronless member of the Krüppel-like family of transcription factors located at Chromosome 7q32. We show that it has monoallelic maternal expression in all embryonic and extra-embryon...

  15. Identification of the imprinted KLF14 transcription factor undergoing human-specific accelerated evolution

    OpenAIRE

    Parker-Katiraee, L.; Carson, A.R.; Yamada, T; Meguro-Horike, M.; Nakabayashi, K.; Scherer, S.W.; Arnaud, P.; Feil, R; Abu-Amero, S. N.; Moore, G.E.; Kaneda, M.; Sasaki, H.; Perry, G. H.; Stone, A C; Lee, C

    2007-01-01

    Imprinted genes are expressed in a parent-of-origin manner and are located in clusters throughout the genome. Aberrations in the expression of imprinted genes on human Chromosome 7 have been suggested to play a role in the etiologies of Russell-Silver Syndrome and autism. We describe the imprinting of KLF14, an intronless member of the Krüppel-like family of transcription factors located at Chromosome 7q32. We show that it has monoallelic maternal expression in all embryonic and extra-embryon...

  16. Dissection of additive, dominance, and imprinting effects for production and reproduction traits in Holstein cattle

    Science.gov (United States)

    Although genome-wide association and genomic selection studies have primarily focused on additive effects, dominance and imprinting effects play an important role in mammalian biology and development. The degree to which these non-additive genetic effects contribute to phenotypic variation and wheth...

  17. Control of PHERES1 Imprinting in Arabidopsis by Direct Tandem Repeats

    Institute of Scientific and Technical Information of China (English)

    Corina Belle R.Villar; Aleksandra Erilova; Grigory Makarevich; Raphael Tr(o)sch; Claudia K(o)hler

    2009-01-01

    Genomic imprinting is an epigenetic phenomenon that causes monoallelic expression of specific genes dependent on the parent-of-origin.Imprinting of the Arabiclopsis gene PHERES1 requires the function of the FERTILIZATION INDEPENDENT SEED (FIS) Polycomb group complex as well as a distally located methylated region containing a tandem triple repeat sequence.In this study,we investigated the regulation of the close PHERES1 homolog PHERES2.We found that PHERES2 is also a direct target gene of the FIS Polycomb group complex,but,in contrast to PHERES1,PHERES2 is equally expressed from maternal and paternal alleles.Thus,PHERES2 is not regulated by genomic imprinting,correlating with the lack of tandem repeats at PHERES2.Eliminating tandem repeats from the PHERES1 locus abolishes PHERES1 imprinting,demonstrating that tandem repeats are essential for PHERES1 imprinting.Taking these results together,our study shows that the recently duplicated genes PHERES1 and PHERES2 are both target genes of the FIS Polycomb group complex but only PHERES1 is regulated by genomic imprinting,which is likely caused by the presence of repeat sequences in the proximity of the PHERES1 locus.

  18. Step & flash imprint lithography

    Directory of Open Access Journals (Sweden)

    Douglas J. Resnick

    2005-02-01

    Full Text Available The escalating cost of next generation lithography (NGL is driven in part by the need for complex sources and optics. The cost for a single NGL tool could soon exceed $50 million, a prohibitive amount for many companies. As a result, several research groups are looking at alternative, low-cost methods for printing sub-100 nm features. Many of these methods are limited in their ability to do precise overlay. In 1999, Willson and Sreenivasan developed step and flash imprint lithography (S-FIL™. The use of a quartz template opens up the potential for optical alignment of the wafer and template. This paper reviews several key aspects of the S-FIL process, including template, tool, ultraviolet (UV-curable monomer, and pattern transfer. Two applications are also presented: contact holes and surface acoustic wave (SAW filters.

  19. Human imprinted chromosomal regions are historical hot-spots of recombination.

    Directory of Open Access Journals (Sweden)

    Ionel Sandovici

    2006-07-01

    Full Text Available Human recombination rates vary along the chromosomes as well as between the two sexes. There is growing evidence that epigenetic factors may have an important influence on recombination rates, as well as on crossover position. Using both public database analysis and wet-bench approaches, we revisited the relationship between increased rates of meiotic recombination and genome imprinting. We constructed metric linkage disequilibrium (LD maps for all human chromosomal regions known to contain one or more imprinted genes. We show that imprinted regions contain significantly more LD units (LDU and have significantly more haplotype blocks of smaller sizes than flanking nonimprinted regions. There is also an excess of hot-spots of recombination at imprinted regions, and this is likely to do with the presence of imprinted genes, per se. These findings indicate that imprinted chromosomal regions are historical "hot-spots" of recombination. We also demonstrate, by direct segregation analysis at the 11p15.5 imprinted region, that there is remarkable agreement between sites of meiotic recombination and steps in LD maps. Although the increase in LDU/Megabase at imprinted regions is not associated with any significant enrichment for any particular sequence class, major sequence determinants of recombination rates seem to differ between imprinted and control regions. Interestingly, fine-mapping of recombination events within the most male meiosis-specific recombination hot-spot of Chromosome 11p15.5 indicates that many events may occur within or directly adjacent to regions that are differentially methylated in somatic cells. Taken together, these findings support the involvement of a combination of specific DNA sequences and epigenetic factors as major determinants of hot-spots of recombination at imprinted chromosomal regions.

  20. Molecular imprinting: perspectives and applications.

    Science.gov (United States)

    Chen, Lingxin; Wang, Xiaoyan; Lu, Wenhui; Wu, Xiaqing; Li, Jinhua

    2016-04-21

    Molecular imprinting technology (MIT), often described as a method of making a molecular lock to match a molecular key, is a technique for the creation of molecularly imprinted polymers (MIPs) with tailor-made binding sites complementary to the template molecules in shape, size and functional groups. Owing to their unique features of structure predictability, recognition specificity and application universality, MIPs have found a wide range of applications in various fields. Herein, we propose to comprehensively review the recent advances in molecular imprinting including versatile perspectives and applications, concerning novel preparation technologies and strategies of MIT, and highlight the applications of MIPs. The fundamentals of MIPs involving essential elements, preparation procedures and characterization methods are briefly outlined. Smart MIT for MIPs is especially highlighted including ingenious MIT (surface imprinting, nanoimprinting, etc.), special strategies of MIT (dummy imprinting, segment imprinting, etc.) and stimuli-responsive MIT (single/dual/multi-responsive technology). By virtue of smart MIT, new formatted MIPs gain popularity for versatile applications, including sample pretreatment/chromatographic separation (solid phase extraction, monolithic column chromatography, etc.) and chemical/biological sensing (electrochemical sensing, fluorescence sensing, etc.). Finally, we propose the remaining challenges and future perspectives to accelerate the development of MIT, and to utilize it for further developing versatile MIPs with a wide range of applications (650 references).

  1. Dual effects of superovulation: loss of maternal and paternal imprinted methylation in a dose-dependent manner.

    Science.gov (United States)

    Market-Velker, Brenna A; Zhang, Liyue; Magri, Lauren S; Bonvissuto, Anne C; Mann, Mellissa R W

    2010-01-01

    Superovulation or ovarian stimulation is currently an indispensable assisted reproductive technology (ART) for human subfertility/infertility treatment. Recently, increased frequencies of imprinting disorders have been correlated with ARTs. Significantly, for Angelman and Beckwith-Wiedemann Syndromes, patients have been identified where ovarian stimulation was the only procedure used by the couple undergoing ART. In many cases, increased risk of genomic imprinting disorders has been attributed to superovulation in combination with inherent subfertility. To distinguish between these contributing factors, carefully controlled experiments are required on spontaneously ovulated, in vivo-fertilized oocytes and their induced-ovulated counterparts, thereby minimizing effects of in vitro manipulations. To this end, effects of superovulation on genomic imprinting were evaluated in a mouse model, where subfertility is not a confounding issue. This work represents the first comprehensive examination of the overall effects of superovulation on imprinted DNA methylation for four imprinted genes in individual blastocyst stage embryos. We demonstrate that superovulation perturbed genomic imprinting of both maternally and paternally expressed genes; loss of Snrpn, Peg3 and Kcnq1ot1 and gain of H19 imprinted methylation were observed. This perturbation was dose-dependent, with aberrant imprinted methylation more frequent at the high hormone dosage. Superovulation is thought to primarily affect oocyte development; thus, effects were expected to be limited to maternal alleles. Our study revealed that maternal as well as paternal H19 methylation was perturbed by superovulation. We postulate that superovulation has dual effects during oogenesis, disrupting acquisition of imprints in growing oocytes, as well as maternal-effect gene products subsequently required for imprint maintenance during pre-implantation development.

  2. The imprinted gene DIO3 is a candidate gene for litter size in pigs.

    Directory of Open Access Journals (Sweden)

    Albart Coster

    Full Text Available Genomic imprinting is an important epigenetic phenomenon, which on the phenotypic level can be detected by the difference between the two heterozygote classes of a gene. Imprinted genes are important in both the development of the placenta and the embryo, and we hypothesized that imprinted genes might be involved in female fertility traits. We therefore performed an association study for imprinted genes related to female fertility traits in two commercial pig populations. For this purpose, 309 SNPs in fifteen evolutionary conserved imprinted regions were genotyped on 689 and 1050 pigs from the two pig populations. A single SNP association study was used to detect additive, dominant and imprinting effects related to four reproduction traits; total number of piglets born, the number of piglets born alive, the total weight of the piglets born and the total weight of the piglets born alive. Several SNPs showed significant (q-value 0.10, but had a similar effect as in the first population. The results of this study indicate a possible association between the imprinted gene DIO3 and female fertility traits in pigs.

  3. Identification of a DNA methylation-independent imprinting control region at the Arabidopsis MEDEA locus.

    Science.gov (United States)

    Wöhrmann, Heike J P; Gagliardini, Valeria; Raissig, Michael T; Wehrle, Wendelin; Arand, Julia; Schmidt, Anja; Tierling, Sascha; Page, Damian R; Schöb, Hanspeter; Walter, Jörn; Grossniklaus, Ueli

    2012-08-15

    Genomic imprinting is exclusive to mammals and seed plants and refers to parent-of-origin-dependent, differential transcription. As previously shown in mammals, studies in Arabidopsis have implicated DNA methylation as an important hallmark of imprinting. The current model suggests that maternally expressed imprinted genes, such as MEDEA (MEA), are activated by the DNA glycosylase DEMETER (DME), which removes DNA methylation established by the DNA methyltransferase MET1. We report the systematic functional dissection of the MEA cis-regulatory region, resulting in the identification of a 200-bp fragment that is necessary and sufficient to mediate MEA activation and imprinted expression, thus containing the imprinting control region (ICR). Notably, imprinted MEA expression mediated by this ICR is independent of DME and MET1, consistent with the lack of any significant DNA methylation in this region. This is the first example of an ICR without differential DNA methylation, suggesting that factors other than DME and MET1 are required for imprinting at the MEA locus.

  4. Imprint lithography advances in LED manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Hershey, Robert; Doyle, Gary; Jones, Chris; LaBrake, Dwayne; Miller, Mike [Molecular Imprints Inc., 1807 West Braker Lane, Building C-11, Austin, TX 78758 (United States)

    2007-07-01

    Imprint lithography is a promising cost effect alternative to e-beam and optical lithography for producing photonic crystals and other nano-scale light extraction and beam directing elements for LEDs; however, there are several challenges that must be overcome before imprint lithography can be applied to typical LED substrates. This paper reviews progress made at Molecular Imprints Inc. (MII) in imprinting representative 3{sup ''} GaN on Sapphire substrates including methods for dealing with substrate non-flatness, multi-die imprint, and imprinting on warped and bowed substrates. The results of imprinting over typical GaN on Sapphire topography and common defects such as fall-on particles and EPI defects is presented along with results on GaN wafers optimized for imprint lithography. Whole wafer thin template replication techniques are also discussed. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Familiarity interferes with filial imprinting

    NARCIS (Netherlands)

    vanKampen, HS; deVos, GJ

    1996-01-01

    The present study was performed to investigate whether and how pre-exposure to an object affects subsequent filial imprinting to that object. In Experiment 1 junglefowl chicks (Gallus gallus spadiceus) were first exposed to either a red object alone (control group), or a red and a yellow object

  6. Imprinted photonic crystal chemical sensors

    NARCIS (Netherlands)

    Boersma, A.; Burghoorn, M.M.A.; Saalmink, M.

    2011-01-01

    In this paper we present the use of Photonic Crystals as chemical sensors. These 2D nanostructured sensors were prepared by nano-imprint lithography during which a nanostructure is transferred from a nickel template into a responsive polymer, that is be specifically tuned to interact with the chemic

  7. Biological imprinting: Some genetic considerations

    African Journals Online (AJOL)

    Mohammad Saad Zaghloul Salem

    2014-06-21

    Jun 21, 2014 ... Abstract Genetic imprinting represents one of the most puzzling, still unexplained, phenomena in genetics. Changing .... acid defined by the new code comprising the new base), .... advantages constitutes the core concept of evolution. Though .... different mechanisms under independent genetic control. 8.

  8. Familiarity interferes with filial imprinting

    NARCIS (Netherlands)

    vanKampen, HS; deVos, GJ

    1996-01-01

    The present study was performed to investigate whether and how pre-exposure to an object affects subsequent filial imprinting to that object. In Experiment 1 junglefowl chicks (Gallus gallus spadiceus) were first exposed to either a red object alone (control group), or a red and a yellow object simu

  9. Identification of imprinted genes subject to parent-of-origin specific expression in Arabidopsis thaliana seeds

    LENUS (Irish Health Repository)

    McKeown, Peter C

    2011-08-12

    Abstract Background Epigenetic regulation of gene dosage by genomic imprinting of some autosomal genes facilitates normal reproductive development in both mammals and flowering plants. While many imprinted genes have been identified and intensively studied in mammals, smaller numbers have been characterized in flowering plants, mostly in Arabidopsis thaliana. Identification of additional imprinted loci in flowering plants by genome-wide screening for parent-of-origin specific uniparental expression in seed tissues will facilitate our understanding of the origins and functions of imprinted genes in flowering plants. Results cDNA-AFLP can detect allele-specific expression that is parent-of-origin dependent for expressed genes in which restriction site polymorphisms exist in the transcripts derived from each allele. Using a genome-wide cDNA-AFLP screen surveying allele-specific expression of 4500 transcript-derived fragments, we report the identification of 52 maternally expressed genes (MEGs) displaying parent-of-origin dependent expression patterns in Arabidopsis siliques containing F1 hybrid seeds (3, 4 and 5 days after pollination). We identified these MEGs by developing a bioinformatics tool (GenFrag) which can directly determine the identities of transcript-derived fragments from (i) their size and (ii) which selective nucleotides were added to the primers used to generate them. Hence, GenFrag facilitates increased throughput for genome-wide cDNA-AFLP fragment analyses. The 52 MEGs we identified were further filtered for high expression levels in the endosperm relative to the seed coat to identify the candidate genes most likely representing novel imprinted genes expressed in the endosperm of Arabidopsis thaliana. Expression in seed tissues of the three top-ranked candidate genes, ATCDC48, PDE120 and MS5-like, was confirmed by Laser-Capture Microdissection and qRT-PCR analysis. Maternal-specific expression of these genes in Arabidopsis thaliana F1 seeds was

  10. Germline mutation in NLRP2 (NALP2 in a familial imprinting disorder (Beckwith-Wiedemann Syndrome.

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    Esther Meyer

    2009-03-01

    Full Text Available Beckwith-Wiedemann syndrome (BWS is a fetal overgrowth and human imprinting disorder resulting from the deregulation of a number of genes, including IGF2 and CDKN1C, in the imprinted gene cluster on chromosome 11p15.5. Most cases are sporadic and result from epimutations at either of the two 11p15.5 imprinting centres (IC1 and IC2. However, rare familial cases may be associated with germline 11p15.5 deletions causing abnormal imprinting in cis. We report a family with BWS and an IC2 epimutation in which affected siblings had inherited different parental 11p15.5 alleles excluding an in cis mechanism. Using a positional-candidate gene approach, we found that the mother was homozygous for a frameshift mutation in exon 6 of NLRP2. While germline mutations in NLRP7 have previously been associated with familial hydatidiform mole, this is the first description of NLRP2 mutation in human disease and the first report of a trans mechanism for disordered imprinting in BWS. These observations are consistent with the hypothesis that NLRP2 has a previously unrecognised role in establishing or maintaining genomic imprinting in humans.

  11. A model for family-based case–control studies of genetic imprinting and epistasis

    Science.gov (United States)

    Li, Xin; Sui, Yihan; Liu, Tian; Wang, Jianxin; Li, Yongci; Lin, Zhenwu; Hegarty, John; Koltun, Walter A.; Wang, Zuoheng

    2014-01-01

    Genetic imprinting, or called the parent-of-origin effect, has been recognized to play an important role in the formation and pathogenesis of human diseases. Although the epigenetic mechanisms that establish genetic imprinting have been a focus of many genetic studies, our knowledge about the number of imprinting genes and their chromosomal locations and interactions with other genes is still scarce, limiting precise inference of the genetic architecture of complex diseases. In this article, we present a statistical model for testing and estimating the effects of genetic imprinting on complex diseases using a commonly used case–control design with family structure. For each subject sampled from a case and control population, we not only genotype its own single nucleotide polymorphisms (SNPs) but also collect its parents’ genotypes. By tracing the transmission pattern of SNP alleles from parental to offspring generation, the model allows the characterization of genetic imprinting effects based on Pearson tests of a 2 × 2 contingency table. The model is expanded to test the interactions between imprinting effects and additive, dominant and epistatic effects in a complex web of genetic interactions. Statistical properties of the model are investigated, and its practical usefulness is validated by a real data analysis. The model will provide a useful tool for genome-wide association studies aimed to elucidate the picture of genetic control over complex human diseases. PMID:23887693

  12. Negative energy balance affects imprint stability in oocytes recovered from postpartum dairy cows.

    Science.gov (United States)

    O'Doherty, Alan M; O'Gorman, Aoife; al Naib, Abdullah; Brennan, Lorraine; Daly, Edward; Duffy, Pat; Fair, Trudee

    2014-09-01

    Ovarian follicle development in post-partum, high-producing dairy cows, occurs in a compromised endogenous metabolic environment (referred to as negative energy balance, NEB). Key events that occur during oocyte/follicle growth, such as the vital process of genomic imprinting, may be detrimentally affected by this altered ovarian environment. Imprinting is crucial for placental function and regulation of fetal growth, therefore failure to establish and maintain imprints during oocyte growth may contribute to early embryonic loss. Using ovum pick-up (OPU), oocytes and follicular fluid samples were recovered from cows between days 20 and 115 post-calving, encompassing the NEB period. In a complimentary study, cumulus oocyte complexes were in vitro matured under high non-esterified fatty acid (NEFA) concentrations and in the presence of the methyl-donor S-adenosylmethionine (SAM). Pyrosequencing revealed the loss of methylation at several imprinted loci in the OPU derived oocytes. The loss of DNA methylation was observed at the PLAGL1 locus in oocytes, following in vitro maturation (IVM) in the presence of elevated NEFAs and SAM. Finally, metabolomic analysis of postpartum follicular fluid samples revealed significant differences in several branched chain amino acids, with fatty acid profiles bearing similarities to those characteristic of lactating dairy cows. These results provide the first evidence that (1) the postpartum ovarian environment may affect maternal imprint acquisition and (2) elevated NEFAs during IVM can lead to the loss of imprinted gene methylation in bovine oocytes.

  13. Human Oocyte-Derived Methylation Differences Persist in the Placenta Revealing Widespread Transient Imprinting.

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    Marta Sanchez-Delgado

    2016-11-01

    Full Text Available Thousands of regions in gametes have opposing methylation profiles that are largely resolved during the post-fertilization epigenetic reprogramming. However some specific sequences associated with imprinted loci survive this demethylation process. Here we present the data describing the fate of germline-derived methylation in humans. With the exception of a few known paternally methylated germline differentially methylated regions (DMRs associated with known imprinted domains, we demonstrate that sperm-derived methylation is reprogrammed by the blastocyst stage of development. In contrast a large number of oocyte-derived methylation differences survive to the blastocyst stage and uniquely persist as transiently methylated DMRs only in the placenta. Furthermore, we demonstrate that this phenomenon is exclusive to primates, since no placenta-specific maternal methylation was observed in mouse. Utilizing single cell RNA-seq datasets from human preimplantation embryos we show that following embryonic genome activation the maternally methylated transient DMRs can orchestrate imprinted expression. However despite showing widespread imprinted expression of genes in placenta, allele-specific transcriptional profiling revealed that not all placenta-specific DMRs coordinate imprinted expression and that this maternal methylation may be absent in a minority of samples, suggestive of polymorphic imprinted methylation.

  14. Human Oocyte-Derived Methylation Differences Persist in the Placenta Revealing Widespread Transient Imprinting

    Science.gov (United States)

    Court, Franck; Martin-Trujillo, Alex; Tayama, Chiharu; Kondova, Ivanela; Bontrop, Ronald; Poo-Llanillo, Maria Eugenia; Nakabayashi, Kazuhiko; Simón, Carlos; Monk, David

    2016-01-01

    Thousands of regions in gametes have opposing methylation profiles that are largely resolved during the post-fertilization epigenetic reprogramming. However some specific sequences associated with imprinted loci survive this demethylation process. Here we present the data describing the fate of germline-derived methylation in humans. With the exception of a few known paternally methylated germline differentially methylated regions (DMRs) associated with known imprinted domains, we demonstrate that sperm-derived methylation is reprogrammed by the blastocyst stage of development. In contrast a large number of oocyte-derived methylation differences survive to the blastocyst stage and uniquely persist as transiently methylated DMRs only in the placenta. Furthermore, we demonstrate that this phenomenon is exclusive to primates, since no placenta-specific maternal methylation was observed in mouse. Utilizing single cell RNA-seq datasets from human preimplantation embryos we show that following embryonic genome activation the maternally methylated transient DMRs can orchestrate imprinted expression. However despite showing widespread imprinted expression of genes in placenta, allele-specific transcriptional profiling revealed that not all placenta-specific DMRs coordinate imprinted expression and that this maternal methylation may be absent in a minority of samples, suggestive of polymorphic imprinted methylation. PMID:27835649

  15. Identification of imprinted genes using a novel screening method based on asynchronous DNA replication

    Energy Technology Data Exchange (ETDEWEB)

    Kawame, H.; Hansen, R.S.; Gartler, S.M. [Univ. of Washington, Seattle, WA (United States)

    1994-09-01

    Genomic imprinting refers to the process of epigenetic change that occurs during germ cell development that results in either maternal- or paternal-specific gene expression. Identification of imprinted genes is of primary importance to the understanding of imprinting mechanisms and the role of specific imprinted genes in human disease. Recently, it has been established that chromosomal regions known to contain imprinted genes replicate asynchronously. We propose a novel screening method to identify imprinted genes based on replication asynchrony as a marker for imprinted domains. Dividing human cells were pulse-labeled with BrdU and separated into different fractions of S-phase by flow cytometry. A library of late-replicating inter-Alu sequences should be enriched in gene-associated sequences that replicate early on one chromosome and late on the other homologue. Clones were analyzed for replication timing by hybridization to inter-Alu replication profiles. Candidates for replication asynchrony exhibited broad or biphasic replication timing, and these were analyzed for chromosomal location by hybridizations to inter-Alu products from a hybrid mapping panel. Initial screening of 123 clones resulted in 3 asynchronously-replicating clones that localized to single chromosomes. Chromosome 17 and chromosome 19 candidates might be located in regions thought to be imprinted by synteny with mouse chromosomes. A chromosome 15 clone was further characterized because of its possible localization to the Prader-Willi/Angelman locus. This sequence was localized outside the region deleted in Prader-Willi patients, and was found to be expressed in human cell lines. Replication asynchrony for this sequence appears to be polymorphic because cells derived from some individuals indicated synchronous replication. This appears to be the first example of a polymorphism in replication asynchrony.

  16. Molecular Imprinting of Macromolecules for Sensor Applications.

    Science.gov (United States)

    Saylan, Yeşeren; Yilmaz, Fatma; Özgür, Erdoğan; Derazshamshir, Ali; Yavuz, Handan; Denizli, Adil

    2017-04-19

    Molecular recognition has an important role in numerous living systems. One of the most important molecular recognition methods is molecular imprinting, which allows host compounds to recognize and detect several molecules rapidly, sensitively and selectively. Compared to natural systems, molecular imprinting methods have some important features such as low cost, robustness, high recognition ability and long term durability which allows molecularly imprinted polymers to be used in various biotechnological applications, such as chromatography, drug delivery, nanotechnology, and sensor technology. Sensors are important tools because of their ability to figure out a potentially large number of analytical difficulties in various areas with different macromolecular targets. Proteins, enzymes, nucleic acids, antibodies, viruses and cells are defined as macromolecules that have wide range of functions are very important. Thus, macromolecules detection has gained great attention in concerning the improvement in most of the studies. The applications of macromolecule imprinted sensors will have a spacious exploration according to the low cost, high specificity and stability. In this review, macromolecules for molecularly imprinted sensor applications are structured according to the definition of molecular imprinting methods, developments in macromolecular imprinting methods, macromolecular imprinted sensors, and conclusions and future perspectives. This chapter follows the latter strategies and focuses on the applications of macromolecular imprinted sensors. This allows discussion on how sensor strategy is brought to solve the macromolecules imprinting.

  17. Imprint switch mutations at Rasgrf1 support conflict hypothesis of imprinting and define a growth control mechanism upstream of IGF1

    Science.gov (United States)

    Drake, Nadia M.; Park, Yoon Jung; Shirali, Aditya S.; Cleland, Thomas A.

    2010-01-01

    Rasgrf1 is imprinted and expressed preferentially from the paternal allele in neonatal mouse brain. At weaning, expression becomes biallelic. Using a mouse model, we assayed the effects of perturbing imprinted Rasgrf1 expression in mice with the following imprinted expression patterns: monoallelic paternal (wild type), monoallelic maternal (maternal only), biallelic (both alleles transcribed), and null (neither allele transcribed). All genotypes exhibit biallelic expression around weaning. Consequences of this transient imprinting perturbation are manifested as overall size differences that correspond to the amount of neonatal Rasgrf1 expressed and are persistent, extending into adulthood. Biallelic mice are the largest and overexpress Rasgrf1 relative to wild-type mice, null mice are the smallest and underexpress Rasgrf1 as neonates, and the two monoallelically expressing genotypes are intermediate and indistinguishable from one another, in both size and Rasgrf1 expression level. Importantly, these data support one of the key underlying assumptions of the “conflict hypothesis” that describes the evolution of genomic imprinting in mammals and supposes that equivalent amounts of imprinted gene expression produce equivalent phenotypes, regardless of which parental allele is transcribed. Concordant with the difference in overall body size, we identify differences in IGF-1 levels, both in serum protein and as liver transcript, and identify additional differential expression of components upstream of IGF-1 release in the GH/IGF-1 axis. These data suggest that imprinted Rasgrf1 expression affects GH/IGF-1 axis function, and that the consequences of Rasgrf1 inputs to this axis persist beyond the time period when expression is restricted via epigenetic mechanisms, suggesting that proper neonatal Rasgrf1 expression levels are critical for development. PMID:19513790

  18. Loss of DNMT1o disrupts imprinted X chromosome inactivation and accentuates placental defects in females.

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    Serge McGraw

    2013-11-01

    Full Text Available The maintenance of key germline derived DNA methylation patterns during preimplantation development depends on stores of DNA cytosine methyltransferase-1o (DNMT1o provided by the oocyte. Dnmt1o(mat-/- mouse embryos born to Dnmt1(Δ1o/Δ1o female mice lack DNMT1o protein and have disrupted genomic imprinting and associated phenotypic abnormalities. Here, we describe additional female-specific morphological abnormalities and DNA hypomethylation defects outside imprinted loci, restricted to extraembryonic tissue. Compared to male offspring, the placentae of female offspring of Dnmt1(Δ1o/Δ1o mothers displayed a higher incidence of genic and intergenic hypomethylation and more frequent and extreme placental dysmorphology. The majority of the affected loci were concentrated on the X chromosome and associated with aberrant biallelic expression, indicating that imprinted X-inactivation was perturbed. Hypomethylation of a key regulatory region of Xite within the X-inactivation center was present in female blastocysts shortly after the absence of methylation maintenance by DNMT1o at the 8-cell stage. The female preponderance of placental DNA hypomethylation associated with maternal DNMT1o deficiency provides evidence of additional roles beyond the maintenance of genomic imprints for DNA methylation events in the preimplantation embryo, including a role in imprinted X chromosome inactivation.

  19. Quantitative analysis of DNA methylation at all human imprinted regions reveals preservation of epigenetic stability in adult somatic tissue

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    Woodfine Kathryn

    2011-01-01

    Full Text Available Abstract Background Genes subject to genomic imprinting are mono-allelically expressed in a parent-of-origin dependent manner. Each imprinted locus has at least one differentially methylated region (DMR which has allele specific DNA methylation and contributes to imprinted gene expression. Once DMRs are established, they are potentially able to withstand normal genome reprogramming events that occur during cell differentiation and germ-line DMRs are stably maintained throughout development. These DMRs, in addition to being either maternally or paternally methylated, have differences in whether methylation was acquired in the germ-line or post fertilization and are present in a variety of genomic locations with different Cytosine-phosphate guanine (CpG densities and CTCF binding capacities. We therefore examined the stability of maintenance of DNA methylation imprints and determined the normal baseline DNA methylation levels in several adult tissues for all imprinted genes. In order to do this, we first developed and validated 50 highly specific, quantitative DNA methylation pyrosequencing assays for the known DMRs associated with human imprinted genes. Results Remarkable stability of the DNA methylation imprint was observed in all germ-line DMRs and paternally methylated somatic DMRs (which maintained average methylation levels of between 35% - 65% in all somatic tissues, independent of gene expression. Maternally methylated somatic DMRs were found to have more variation with tissue specific methylation patterns. Most DMRs, however, showed some intra-individual variability for DNA methylation levels in peripheral blood, suggesting that more than one DMR needs to be examined in order to get an overall impression of the epigenetic stability in a tissue. The plasticity of DNA methylation at imprinted genes was examined in a panel of normal and cancer cell lines. All cell lines showed changes in DNA methylation, especially at the paternal germ

  20. Imprinting of the polycomb group gene MEDEA serves as a ploidy sensor in Arabidopsis.

    Science.gov (United States)

    Erilova, Aleksandra; Brownfield, Lynette; Exner, Vivien; Rosa, Marisa; Twell, David; Mittelsten Scheid, Ortrun; Hennig, Lars; Köhler, Claudia

    2009-09-01

    Balanced maternal and paternal genome contributions are a requirement for successful seed development. Unbalanced contributions often cause seed abortion, a phenomenon that has been termed "triploid block." Misregulation of imprinted regulatory genes has been proposed to be the underlying cause for abnormalities in growth and structure of the endosperm in seeds with deviating parental contributions. We identified a mutant forming unreduced pollen that enabled us to investigate direct effects of unbalanced parental genome contributions on seed development and to reveal the underlying molecular mechanism of dosage sensitivity. We provide evidence that parent-of-origin-specific expression of the Polycomb group (PcG) gene MEDEA is causally responsible for seed developmental aberrations in Arabidopsis seeds with increased paternal genome contributions. We propose that imprinted expression of PcG genes is an evolutionary conserved mechanism to balance parental genome contributions in embryo nourishing tissues.

  1. Gene dosage effects of the imprinted delta-like homologue 1 (dlk1/pref1 in development: implications for the evolution of imprinting.

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    Simao Teixeira da Rocha

    2009-02-01

    Full Text Available Genomic imprinting is a normal process that causes genes to be expressed according to parental origin. The selective advantage conferred by imprinting is not understood but is hypothesised to act on dosage-critical genes. Here, we report a unique model in which the consequences of a single, double, and triple dosage of the imprinted Dlk1/Pref1, normally repressed on the maternally inherited chromosome, can be assessed in the growing embryo. BAC-transgenic mice were generated that over-express Dlk1 from endogenous regulators at all sites of embryonic activity. Triple dosage causes lethality associated with major organ abnormalities. Embryos expressing a double dose of Dlk1, recapitulating loss of imprinting, are growth enhanced but fail to thrive in early life, despite the early growth advantage. Thus, any benefit conferred by increased embryonic size is offset by postnatal lethality. We propose a negative correlation between gene dosage and survival that fixes an upper limit on growth promotion by Dlk1, and we hypothesize that trade-off between growth and lethality might have driven imprinting at this locus.

  2. High-throughput analysis of candidate imprinted genes and allele-specific gene expression in the human term placenta

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    Clark Taane G

    2010-04-01

    Full Text Available Abstract Background Imprinted genes show expression from one parental allele only and are important for development and behaviour. This extreme mode of allelic imbalance has been described for approximately 56 human genes. Imprinting status is often disrupted in cancer and dysmorphic syndromes. More subtle variation of gene expression, that is not parent-of-origin specific, termed 'allele-specific gene expression' (ASE is more common and may give rise to milder phenotypic differences. Using two allele-specific high-throughput technologies alongside bioinformatics predictions, normal term human placenta was screened to find new imprinted genes and to ascertain the extent of ASE in this tissue. Results Twenty-three family trios of placental cDNA, placental genomic DNA (gDNA and gDNA from both parents were tested for 130 candidate genes with the Sequenom MassArray system. Six genes were found differentially expressed but none imprinted. The Illumina ASE BeadArray platform was then used to test 1536 SNPs in 932 genes. The array was enriched for the human orthologues of 124 mouse candidate genes from bioinformatics predictions and 10 human candidate imprinted genes from EST database mining. After quality control pruning, a total of 261 informative SNPs (214 genes remained for analysis. Imprinting with maternal expression was demonstrated for the lymphocyte imprinted gene ZNF331 in human placenta. Two potential differentially methylated regions (DMRs were found in the vicinity of ZNF331. None of the bioinformatically predicted candidates tested showed imprinting except for a skewed allelic expression in a parent-specific manner observed for PHACTR2, a neighbour of the imprinted PLAGL1 gene. ASE was detected for two or more individuals in 39 candidate genes (18%. Conclusions Both Sequenom and Illumina assays were sensitive enough to study imprinting and strong allelic bias. Previous bioinformatics approaches were not predictive of new imprinted genes

  3. Molecularly imprinted polymers as synthetic mimics of bioreceptors. 1. General principles of molecular imprinting

    Directory of Open Access Journals (Sweden)

    Sergeyeva T. A.

    2009-08-01

    Full Text Available The review is devoted to analysis of the publications in the area of synthesis of artificial mimics of biological receptors using the method of molecular imprinting. General principles of molecular imprinting as well as main types of polymers being used in molecular imprinting are described. The special attention is paid to the polymers-biomimics synthesized using the method of non-covalent molecular imprinting.

  4. Molecularly imprinted polymers as synthetic mimics of bioreceptors. 1. General principles of molecular imprinting

    OpenAIRE

    Sergeyeva T. A.

    2009-01-01

    The review is devoted to analysis of the publications in the area of synthesis of artificial mimics of biological receptors using the method of molecular imprinting. General principles of molecular imprinting as well as main types of polymers being used in molecular imprinting are described. The special attention is paid to the polymers-biomimics synthesized using the method of non-covalent molecular imprinting.

  5. Molecular imprinting of protein by coordinate interaction

    Institute of Scientific and Technical Information of China (English)

    Jun Wang; Zhen Dong Hua; Zhi Yong Chen; Yuan Zong Li; Mei Ping Zhao

    2009-01-01

    In this article, a novel strong interaction by forming complex between bovine serum albumin (BSA) and copper ion was utilized for the preparation of molecular imprinted hydrogel in aqueous solution. Results show that the inclusion of copper ion in preparation can bridge the template BSA and functional monomers together and improve the imprinting effect compared to the polymer made without copper ion added. High selectivity factor and large adsorption capacity are also observed for the obtained BSA-imprinted hydrogel.

  6. Computational Insights on Sulfonamide Imprinted Polymers

    OpenAIRE

    Chartchalerm Isarankura-Na-Ayudhya; Chanin Nantasenamat; Prasit Buraparuangsang; Theeraphon Piacham; Leif Bülow; Lei Ye; Virapong Prachayasittikul

    2008-01-01

    Molecular imprinting is one of the most efficient methods for preparing synthetic receptors that possess user defined recognition properties. Despite general success of non-covalent imprinting for a large variety of templates, some groups of compounds remain difficult to tackle due to their structural complexity. In this study we investigate preparation of molecularly imprinted polymers that can bind sulfonamide compounds, which represent important drug candidates. Compared to the biological ...

  7. Imprinting and recalling cortical ensembles.

    Science.gov (United States)

    Carrillo-Reid, Luis; Yang, Weijian; Bando, Yuki; Peterka, Darcy S; Yuste, Rafael

    2016-08-12

    Neuronal ensembles are coactive groups of neurons that may represent building blocks of cortical circuits. These ensembles could be formed by Hebbian plasticity, whereby synapses between coactive neurons are strengthened. Here we report that repetitive activation with two-photon optogenetics of neuronal populations from ensembles in the visual cortex of awake mice builds neuronal ensembles that recur spontaneously after being imprinted and do not disrupt preexisting ones. Moreover, imprinted ensembles can be recalled by single- cell stimulation and remain coactive on consecutive days. Our results demonstrate the persistent reconfiguration of cortical circuits by two-photon optogenetics into neuronal ensembles that can perform pattern completion. Copyright © 2016, American Association for the Advancement of Science.

  8. Molecularly imprinted polymers: synthesis and characterisation.

    Science.gov (United States)

    Cormack, Peter A G; Elorza, Amaia Zurutuza

    2004-05-01

    This short review aims to present, in clear English, a summary of the principal synthetic considerations pertaining to good practice in the polymerisation aspects of molecular imprinting, and is primarily aimed at researchers familiar with molecular imprinting methods but with little or no prior experience in polymer synthesis. It is our hope that this will facilitate researchers to plan their own syntheses of molecular imprints in a more logical and structured fashion, and to begin to appreciate the limitations of the present synthetic approaches in this molecularly complex area, as well as the scope for rationally designing improved imprinted materials in the future.

  9. Preparation of quercetin imprinted core-shell organosilicate microspheres using surface imprinting technique

    Institute of Scientific and Technical Information of China (English)

    Peng Yang; Wen Dan Hou; Hong Deng Qiu; Xia Liu; Sheng Xiang Jiang

    2012-01-01

    In this work,the quercetin imprinted core-shell microspheres were prepared using silica surface imprinting technique.A simple sol-gel procedure was used for the synthesis of the imprinted materials with 3-aminopropyltriethoxysilane as functional monomer and tetraethyl orthosilicate as crosslinker.The SEM images indicated that the MIPs shell was successfully grafted onto the silica surface.The characteristics of the molecularly imprinted polymers such as capacity,selectivity and absorption dynamic were investigated by rebinding experiments.The results showed that the prepared MIPs had good imprinting effect and adsorption amount of quercetin.

  10. Loss of imprinting at the Dlk1-Gtl2 locus caused by insertional mutagenesis in the Gtl2 5' region

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    Appelbe Oliver K

    2006-10-01

    Full Text Available Abstract Background The Dlk1 and Gtl2 genes define a region of mouse chromosome 12 that is subject to genomic imprinting, the parental allele-specific expression of a gene. Although imprinted genes play important roles in growth and development, the mechanisms by which imprinting is established and maintained are poorly understood. Differentially methylated regions (DMRs, which carry methylation on only one parental allele, are involved in imprinting control at many loci. The Dlk1-Gtl2 region contains three known DMRs, the Dlk1 DMR in the 3' region of Dlk1, the intergenic DMR 15 kb upstream of Gtl2, and the Gtl2 DMR at the Gtl2 promoter. Three mouse models are analyzed here that provide new information about the regulation of Dlk1-Gtl2 imprinting. Results A previously existing insertional mutation (Gtl2lacZ, and a targeted deletion in which the Gtl2 upstream region was replaced by a Neo cassette (Gtl2Δ5'Neo, display partial lethality and dwarfism upon paternal inheritance. Molecular characterization shows that both mutations cause loss of imprinting and changes in expression of the Dlk1, Gtl2 and Meg8/Rian genes. Dlk1 levels are decreased upon paternal inheritance of either mutation, suggesting Dlk1 may be causative for the lethality and dwarfism. Loss of imprinting on the paternal chromosome in both Gtl2lacZ and Gtl2Δ5'Neo mice is accompanied by the loss of paternal-specific Gtl2 DMR methylation, while maternal loss of imprinting suggests a previously unknown regulatory role for the maternal Gtl2 DMR. Unexpectedly, when the Neo gene is excised, Gtl2Δ5' animals are of normal size, imprinting is unchanged and the Gtl2 DMR is properly methylated. The exogenous DNA sequences integrated upstream of Gtl2 are therefore responsible for the growth and imprinting effects. Conclusion These data provide further evidence for the coregulation of the imprinted Dlk1 and Gtl2 genes, and support a role for Dlk1 as an important neonatal growth factor. The

  11. Maintenance of Xist Imprinting Depends on Chromatin Condensation State and Rnf12 Dosage in Mice

    Science.gov (United States)

    Fukuda, Atsushi; Mitani, Atsushi; Miyashita, Toshiyuki; Sado, Takashi; Umezawa, Akihiro; Akutsu, Hidenori

    2016-01-01

    In female mammals, activation of Xist (X-inactive specific transcript) is essential for establishment of X chromosome inactivation. During early embryonic development in mice, paternal Xist is preferentially expressed whereas maternal Xist (Xm-Xist) is silenced. Unlike autosomal imprinted genes, Xist imprinting for Xm-Xist silencing was erased in cloned or parthenogenetic but not fertilized embryos. However, the molecular mechanism underlying the variable nature of Xm-Xist imprinting is poorly understood. Here, we revealed that Xm-Xist silencing depends on chromatin condensation states at the Xist/Tsix genomic region and on Rnf12 expression levels. In early preimplantation, chromatin decondensation via H3K9me3 loss and histone acetylation gain caused Xm-Xist derepression irrespective of embryo type. Although the presence of the paternal genome during pronuclear formation impeded Xm-Xist derepression, Xm-Xist was robustly derepressed when the maternal genome was decondensed before fertilization. Once Xm-Xist was derepressed by chromatin alterations, the derepression was stably maintained and rescued XmXpΔ lethality, indicating that loss of Xm-Xist imprinting was irreversible. In late preimplantation, Oct4 served as a chromatin opener to create transcriptional permissive states at Xm-Xist/Tsix genomic loci. In parthenogenetic embryos, Rnf12 overdose caused Xm-Xist derepression via Xm-Tsix repression; physiological Rnf12 levels were essential for Xm-Xist silencing maintenance in fertilized embryos. Thus, chromatin condensation and fine-tuning of Rnf12 dosage were crucial for Xist imprint maintenance by silencing Xm-Xist. PMID:27788132

  12. DEMETER DNA glycosylase establishes MEDEA polycomb gene self-imprinting by allele-specific demethylation.

    Science.gov (United States)

    Gehring, Mary; Huh, Jin Hoe; Hsieh, Tzung-Fu; Penterman, Jon; Choi, Yeonhee; Harada, John J; Goldberg, Robert B; Fischer, Robert L

    2006-02-10

    MEDEA (MEA) is an Arabidopsis Polycomb group gene that is imprinted in the endosperm. The maternal allele is expressed and the paternal allele is silent. MEA is controlled by DEMETER (DME), a DNA glycosylase required to activate MEA expression, and METHYLTRANSFERASE I (MET1), which maintains CG methylation at the MEA locus. Here we show that DME is responsible for endosperm maternal-allele-specific hypomethylation at the MEA gene. DME can excise 5-methylcytosine in vitro and when expressed in E. coli. Abasic sites opposite 5-methylcytosine inhibit DME activity and might prevent DME from generating double-stranded DNA breaks. Unexpectedly, paternal-allele silencing is not controlled by DNA methylation. Rather, Polycomb group proteins that are expressed from the maternal genome, including MEA, control paternal MEA silencing. Thus, DME establishes MEA imprinting by removing 5-methylcytosine to activate the maternal allele. MEA imprinting is subsequently maintained in the endosperm by maternal MEA silencing the paternal allele.

  13. Analysis of the expression of putatively imprinted genes in bovine peri-implantation embryos

    DEFF Research Database (Denmark)

    Tveden-Nyborg, Pernille Yde; Alexopoulos, N.I.; Cooney, M.A.

    2008-01-01

    imprinted genes (Ata3, Dlk1, Gnas, Grb10, Magel2, Mest-1, Ndn and Sgce) in bovine peri-implantation embryos. Two embryonic developmental stages were examined, Day 14 and Day 21. The gene expression pattern of single embryos was recorded for in vivo, in vitro produced (IVP) and parthenogenetic embryos...... (LOS) in bovine embryos resulting in increased embryonic morbidity and mortality. In the bovine, limited numbers of imprinted genes have been studied and studies have primarily been restricted to pre-implantation stages. This study reports original data on the expression pattern of 8 putatively...... procedures, either by in vitro maturation, fertilization or culture. In conclusion, effects of genomic imprinting and of in vitro procedures for embryo production may influence the success of bovine embryo implantation....

  14. The parental non-equivalence of imprinting control regions during mammalian development and evolution.

    Directory of Open Access Journals (Sweden)

    Reiner Schulz

    2010-11-01

    Full Text Available In mammals, imprinted gene expression results from the sex-specific methylation of imprinted control regions (ICRs in the parental germlines. Imprinting is linked to therian reproduction, that is, the placenta and imprinting emerged at roughly the same time and potentially co-evolved. We assessed the transcriptome-wide and ontology effect of maternally versus paternally methylated ICRs at the developmental stage of setting of the chorioallantoic placenta in the mouse (8.5dpc, using two models of imprinting deficiency including completely imprint-free embryos. Paternal and maternal imprints have a similar quantitative impact on the embryonic transcriptome. However, transcriptional effects of maternal ICRs are qualitatively focused on the fetal-maternal interface, while paternal ICRs weakly affect non-convergent biological processes, with little consequence for viability at 8.5dpc. Moreover, genes regulated by maternal ICRs indirectly influence genes regulated by paternal ICRs, while the reverse is not observed. The functional dominance of maternal imprints over early embryonic development is potentially linked to selection pressures favoring methylation-dependent control of maternal over paternal ICRs. We previously hypothesized that the different methylation histories of ICRs in the maternal versus the paternal germlines may have put paternal ICRs under higher mutational pressure to lose CpGs by deamination. Using comparative genomics of 17 extant mammalian species, we show here that, while ICRs in general have been constrained to maintain more CpGs than non-imprinted sequences, the rate of CpG loss at paternal ICRs has indeed been higher than at maternal ICRs during evolution. In fact, maternal ICRs, which have the characteristics of CpG-rich promoters, have gained CpGs compared to non-imprinted CpG-rich promoters. Thus, the numerical and, during early embryonic development, functional dominance of maternal ICRs can be explained as the

  15. Trichostatin A rescues the disrupted imprinting induced by somatic cell nuclear transfer in pigs.

    Directory of Open Access Journals (Sweden)

    Yanjun Huan

    Full Text Available Imprinting disorders induced by somatic cell nuclear transfer (SCNT usually lead to the abnormalities of cloned animals and low cloning efficiency. Histone deacetylase inhibitors have been shown to improve gene expression, genomic methylation reprogramming and the development of cloned embryos, however, the imprinting statuses in these treated embryos and during their subsequent development remain poorly studied. In this study, we investigated the dynamics of H19/Igf2 methylation and transcription in porcine cloned embryos treated with trichostatin A (TSA, and examined H19/Igf2 imprinting patterns in cloned fetuses and piglets. Our results showed that compared with the maintenance of H19/Igf2 methylation in fertilized embryos, cloned embryos displayed aberrant H19/Igf2 methylation and lower H19/Igf2 transcripts. When TSA enhanced the development of cloned embryos, the disrupted H19/Igf2 imprinting was largely rescued in these treated embryos, more similar to those detected in fertilized counterparts. Further studies displayed that TSA effectively rescued the disrupted imprinting of H19/Igf2 in cloned fetuses and piglets, prevented the occurrence of cloned fetus and piglet abnormalities, and enhanced the full-term development of cloned embryos. In conclusion, our results demonstrated that aberrant imprinting induced by SCNT led to the abnormalities of cloned fetuses and piglets and low cloning efficiency, and TSA rescued the disrupted imprinting in cloned embryos, fetuses and piglets, and prevented the occurrence of cloned fetus and piglet abnormalities, thereby improving the development of cloned embryos. This study would have important implications in improving cloning efficiency and the health of cloned animals.

  16. FILIAL IMPRINTING AND ASSOCIATIVE LEARNING - SIMILAR MECHANISMS

    NARCIS (Netherlands)

    van Kampen, Hendrik

    1993-01-01

    This paper reviews a series of experiments designed to investigate whether features characteristic for associative learning are also true of filial imprinting. Phenomena resembling blocking and overshadowing in associative learning may occur during imprinting on two different objects, but it is

  17. Imprinting disorders after assisted reproductive technologies

    DEFF Research Database (Denmark)

    Lidegaard, Øjvind; Pinborg, Anja; Andersen, Anders Nyboe

    2006-01-01

    To assess the evidence of an increased risk of imprinting diseases in children born after use of assisted reproductive technologies.......To assess the evidence of an increased risk of imprinting diseases in children born after use of assisted reproductive technologies....

  18. FILIAL IMPRINTING AND ASSOCIATIVE LEARNING - SIMILAR MECHANISMS

    NARCIS (Netherlands)

    van Kampen, Hendrik

    1993-01-01

    This paper reviews a series of experiments designed to investigate whether features characteristic for associative learning are also true of filial imprinting. Phenomena resembling blocking and overshadowing in associative learning may occur during imprinting on two different objects, but it is unli

  19. The Haglund imprint on the patella.

    Science.gov (United States)

    Graf, J; Bernd, L; Simank, H G; Niethard, F U

    1993-12-01

    Seven hundred and five radiographs of the knee were examined and 17.6% showed a so-called Haglund imprint on the patella. The incidence was the same in patients with chondromalacia and in a control group. There was no statistical difference regarding age, sex and body weight. Haglund's imprint is a variation from the normal and is of no diagnostic value.

  20. Molecularly Imprinted Materials: Towards the Next Generation

    Science.gov (United States)

    2002-04-05

    prepare molecularly imprinted microgels [13]. By adjusting monomer concentration and solvent composition, the cross-linking polymerization produced...mainly intramolecularly cross-linked microgels . The model system utilized covalent bonds between a sugar derivative and a boronic acid monomer in the...imprinting and rebinding reactions. Although binding selectivity of the obtained polymers was only modest, the obtainable nanometer-sized microgels were

  1. Patterns of hybrid loss of imprinting reveal tissue- and cluster-specific regulation.

    Directory of Open Access Journals (Sweden)

    Christopher D Wiley

    Full Text Available BACKGROUND: Crosses between natural populations of two species of deer mice, Peromyscus maniculatus (BW, and P. polionotus (PO, produce parent-of-origin effects on growth and development. BW females mated to PO males (bwxpo produce growth-retarded but otherwise healthy offspring. In contrast, PO females mated to BW males (POxBW produce overgrown and severely defective offspring. The hybrid phenotypes are pronounced in the placenta and include POxBW conceptuses which lack embryonic structures. Evidence to date links variation in control of genomic imprinting with the hybrid defects, particularly in the POxBW offspring. Establishment of genomic imprinting is typically mediated by gametic DNA methylation at sites known as gDMRs. However, imprinted gene clusters vary in their regulation by gDMR sequences. METHODOLOGY/PRINCIPAL FINDINGS: Here we further assess imprinted gene expression and DNA methylation at different cluster types in order to discern patterns. These data reveal POxBW misexpression at the Kcnq1ot1 and Peg3 clusters, both of which lose ICR methylation in placental tissues. In contrast, some embryonic transcripts (Peg10, Kcnq1ot1 reactivated the silenced allele with little or no loss of DNA methylation. Hybrid brains also display different patterns of imprinting perturbations. Several cluster pairs thought to use analogous regulatory mechanisms are differentially affected in the hybrids. CONCLUSIONS/SIGNIFICANCE: These data reinforce the hypothesis that placental and somatic gene regulation differs significantly, as does that between imprinted gene clusters and between species. That such epigenetic regulatory variation exists in recently diverged species suggests a role in reproductive isolation, and that this variation is likely to be adaptive.

  2. Molecularly Imprinted Nanomaterials for Sensor Applications

    Directory of Open Access Journals (Sweden)

    Muhammad Irshad

    2013-11-01

    Full Text Available Molecular imprinting is a well-established technology to mimic antibody-antigen interaction in a synthetic platform. Molecularly imprinted polymers and nanomaterials usually possess outstanding recognition capabilities. Imprinted nanostructured materials are characterized by their small sizes, large reactive surface area and, most importantly, with rapid and specific analysis of analytes due to the formation of template driven recognition cavities within the matrix. The excellent recognition and selectivity offered by this class of materials towards a target analyte have found applications in many areas, such as separation science, analysis of organic pollutants in water, environmental analysis of trace gases, chemical or biological sensors, biochemical assays, fabricating artificial receptors, nanotechnology, etc. We present here a concise overview and recent developments in nanostructured imprinted materials with respect to various sensor systems, e.g., electrochemical, optical and mass sensitive, etc. Finally, in light of recent studies, we conclude the article with future perspectives and foreseen applications of imprinted nanomaterials in chemical sensors.

  3. Astrobiological Molecularly Imprinted Polymer Sensors

    Science.gov (United States)

    Izenberg, N. R.; Murray, G. M.; van Houten, K. A.; Hofstra, A. A.

    2005-12-01

    Development of Molecularly Imprinted Polymer (MIP) sensors for astrobiology is intended to provide a new class of microlaboratory sensors compatible with other life or biomarker detection. Molecular imprinting is a process for making selective binding sites in synthetic polymers. The process may be approached by designing the recognition site or by simply choosing monomers that may have favorable interactions with the imprinting molecule. We are working to apply this methodology to astrobiology for development of a reliable, low cost, low mass, low power consumption sensor technology for quantitative in-situ analysis of biochemistry, biomarkers, and other indicators of astrobiological importance. Specific goals of the project are: 1) To develop a general methodology and specific methods for MIP-based sensor construction. The overall methodology will guide procedures for design and testing of any desired sensor. Specific methods will be applied to key families and specific species of astrobiological interest, i.e., alkanes (and Polycyclic aromatic hydrocarbons - PAHs), amino acids, steroids, and hopanes; 2) To construct and characterize the general family and specific species sensors. We will test for accuracy, precision, interferences, and limitations of the sensor against blanks, standards, and known terrestrial biological environment samples. Additional testing will determine sturdiness and longevity of sensors after exposure to transit conditions (launch and space environment), and at potential target environments (pressure, temperature, pH, etc.); and 3) To construct and demonstrate the combination of multiple sensors into a viable prototype instrument, and roadmap the expansion of potential instrument capabilities and exploration of the ultimate environmental limitations of the technology, and the necessary changes and additions to create a mission-ready instrument. Initial work has resulted successful detection of aqueous alanine (D and L) with simple MIP

  4. Identification of clustered YY1 binding sites in Imprinting Control Regions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J D; Hinz, A; Bergmann, A; Huang, J; Ovcharenko, I; Stubbs, L; Kim, J

    2006-04-19

    Mammalian genomic imprinting is regulated by Imprinting Control Regions (ICRs) that are usually associated with tandem arrays of transcription factor binding sites. In the current study, the sequence features derived from a tandem array of YY1 binding sites of Peg3-DMR (differentially methylated region) led us to identify three additional clustered YY1 binding sites, which are also localized within the DMRs of Xist, Tsix, and Nespas. These regions have been shown to play a critical role as ICRs for the regulation of surrounding genes. These ICRs have maintained a tandem array of YY1 binding sites during mammalian evolution. The in vivo binding of YY1 to these regions is allele-specific and only to the unmethylated active alleles. Promoter/enhancer assays suggest that a tandem array of YY1 binding sites function as a potential orientation-dependent enhancer. Insulator assays revealed that the enhancer-blocking activity is detected only in the YY1 binding sites of Peg3-DMR but not in the YY1 binding sites of other DMRs. Overall, our identification of three additional clustered YY1 binding sites in imprinted domains suggests a significant role for YY1 in mammalian genomic imprinting.

  5. Neural basis of imprinting behavior in chicks.

    Science.gov (United States)

    Nakamori, Tomoharu; Maekawa, Fumihiko; Sato, Katsushige; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

    2013-01-01

    Newly hatched chicks memorize the characteristics of the first moving object they encounter, and subsequently show a preference for it. This "imprinting" behavior is an example of infant learning and is elicited by visual and/or auditory cues. Visual information of imprinting stimuli in chicks is first processed in the visual Wulst (VW), a telencephalic area corresponding to the mammalian visual cortex, congregates in the core region of the hyperpallium densocellulare (HDCo) cells, and transmitted to the intermediate medial mesopallium (IMM), a region similar to the mammalian association cortex. The imprinting memory is stored in the IMM, and activities of IMM neurons are altered by imprinting. Imprinting also induces functional and structural plastic changes of neurons in the circuit that links the VW and the IMM. Of these neurons, the activity of the HDCo cells is strongly influenced by imprinting. Expression and modulation of NR2B subunit-containing N-methyl-D-aspartate (NMDA) receptors in the HDCo cells are crucial for plastic changes in this circuit as well as the process of visual imprinting. Thus, elucidation of cellular and molecular mechanisms underlying the plastic changes that occurred in the HDCo cells may provide useful knowledge about infant learning. © 2012 The Authors Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

  6. Molecular imprinting of bulk, microporous silica

    Science.gov (United States)

    Katz, Alexander; Davis, Mark E.

    2000-01-01

    Molecular imprinting aims to create solid materials containing chemical functionalities that are spatially organized by covalent or non-covalent interactions with imprint (or template) molecules during the synthesis process. Subsequent removal of the imprint molecules leaves behind designed sites for the recognition of small molecules, making the material ideally suited for applications such as separations, chemical sensing and catalysis. Until now, the molecular imprinting of bulk polymers and polymer and silica surfaces has been reported, but the extension of these methods to a wider range of materials remains problematic. For example, the formation of substrate-specific cavities within bulk silica, while conceptually straightforward, has been difficult to accomplish experimentally. Here we describe the imprinting of bulk amorphous silicas with single aromatic rings carrying up to three 3-aminopropyltriethoxysilane side groups; this generates and occupies microporosity and attaches functional organic groups to the pore walls in a controlled fashion. The triethoxysilane part of the molecules' side groups is incorporated into the silica framework during sol-gel synthesis, and subsequent removal of the aromatic core creates a cavity with spatially organized aminopropyl groups covalently anchored to the pore walls. We find that the imprinted silicas act as shape-selective base catalysts. Our strategy can be extended to imprint other functional groups, which should give access to a wide range of functionalized materials.

  7. Automated visual inspection of imprinted pharmaceutical tablets

    Science.gov (United States)

    Bukovec, Marko; Špiclin, Žiga; Pernuš, Franjo; Likar, Boštjan

    2007-09-01

    This paper is on automated visual inspection of tablets that may, in contrast to manual tablet sorting, provide objective and reproducible tablet quality assurance. Visual inspection of the ever-increasing numbers of produced imprinted tablets, regulatory enforced for unambiguous identification of active ingredients and dosage strength of each tablet, is especially demanding. The problem becomes more tractable by incorporating some a priori knowledge of the imprint shape and/or appearance. For this purpose, we consider two alternative automated tablet defect detection methods. The geometrical method, incorporating geometrical a priori knowledge of the imprint shape, enables specific inspection of the imprinted and non-imprinted tablet surface, while the statistical method exploits statistical a priori knowledge of tablet surface appearance, derived from a training image database. The two methods were evaluated on a large tablet image database, consisting of 3445 images of four types of imprinted tablets, with and without typical production defects. A 'gold standard' for testing the performances of the two inspection methods was established by manually classifying the tablets into good and five defective classes. The results, obtained by ROC (receiver operating characteristics) analysis, indicate that the statistical method yields better defect detection sensitivity and specificity than the geometrical method. Both presented image analysis methods are quite general and promising tools for automated visual inspection of imprinted pharmaceutical tablets.

  8. Exercise-associated DNA methylation change in skeletal muscle and the importance of imprinted genes: a bioinformatics meta-analysis.

    Science.gov (United States)

    Brown, William M

    2015-12-01

    Epigenetics is the study of processes--beyond DNA sequence alteration--producing heritable characteristics. For example, DNA methylation modifies gene expression without altering the nucleotide sequence. A well-studied DNA methylation-based phenomenon is genomic imprinting (ie, genotype-independent parent-of-origin effects). We aimed to elucidate: (1) the effect of exercise on DNA methylation and (2) the role of imprinted genes in skeletal muscle gene networks (ie, gene group functional profiling analyses). Gene ontology (ie, gene product elucidation)/meta-analysis. 26 skeletal muscle and 86 imprinted genes were subjected to g:Profiler ontology analysis. Meta-analysis assessed exercise-associated DNA methylation change. g:Profiler found four muscle gene networks with imprinted loci. Meta-analysis identified 16 articles (387 genes/1580 individuals) associated with exercise. Age, method, sample size, sex and tissue variation could elevate effect size bias. Only skeletal muscle gene networks including imprinted genes were reported. Exercise-associated effect sizes were calculated by gene. Age, method, sample size, sex and tissue variation were moderators. Six imprinted loci (RB1, MEG3, UBE3A, PLAGL1, SGCE, INS) were important for muscle gene networks, while meta-analysis uncovered five exercise-associated imprinted loci (KCNQ1, MEG3, GRB10, L3MBTL1, PLAGL1). DNA methylation decreased with exercise (60% of loci). Exercise-associated DNA methylation change was stronger among older people (ie, age accounted for 30% of the variation). Among older people, genes exhibiting DNA methylation decreases were part of a microRNA-regulated gene network functioning to suppress cancer. Imprinted genes were identified in skeletal muscle gene networks and exercise-associated DNA methylation change. Exercise-associated DNA methylation modification could rewind the 'epigenetic clock' as we age. CRD42014009800. Published by the BMJ Publishing Group Limited. For permission to use (where

  9. Ferroelectric capacitor with reduced imprint

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Jr., Joseph T. (13609 Verbena Pl., NE., Albuquerque, NM 87112); Warren, William L. (7716 Wm. Moyers Ave., NE., Albuquerque, NM 87122); Tuttle, Bruce A. (12808 Lillian Pl., NE., Albuquerque, NM 87122); Dimos, Duane B. (6105 Innsbrook Ct., NE., Albuquerque, NM 87111); Pike, Gordon E. (1609 Cedar Ridge, NE., Albuquerque, NM 87112)

    1997-01-01

    An improved ferroelectric capacitor exhibiting reduced imprint effects in comparison to prior art capacitors. A capacitor according to the present invention includes top and bottom electrodes and a ferroelectric layer sandwiched between the top and bottom electrodes, the ferroelectric layer comprising a perovskite structure of the chemical composition ABO.sub.3 wherein the B-site comprises first and second elements and a dopant element that has an oxidation state greater than +4. The concentration of the dopant is sufficient to reduce shifts in the coercive voltage of the capacitor with time. In the preferred embodiment of the present invention, the ferroelectric element comprises Pb in the A-site, and the first and second elements are Zr and Ti, respectively. The preferred dopant is chosen from the group consisting of Niobium, Tantalum, and Tungsten. In the preferred embodiment of the present invention, the dopant occupies between 1 and 8% of the B-sites.

  10. Tailoring Imprinted Titania Nanoparticles for Purines Recognition

    Directory of Open Access Journals (Sweden)

    Adnan Mujahid

    2015-01-01

    Full Text Available Molecular imprinted titania nanoparticles were developed for selective recognition of purines, for example, guanine and its final oxidation product uric acid. Titania nanoparticles were prepared by hydrolysis of titanium butoxide as precursor in the presence of pattern molecules. The morphology of synthesized nanoparticles is evaluated by SEM images. Recognition characteristics of imprinted titania nanoparticles are studied by exposing them to standard solution of guanine and uric acid, respectively. The resultant change in their concentration is determined by UV/Vis analysis that indicated imprinted titania nanoparticles possess high affinity for print molecules. In both cases, nonimprinted titania is taken as control to observe nonspecific binding interactions. Cross sensitivity studies suggested that imprinted titania is at least five times more selective for binding print molecules than competing analyte thus indicating its potential for bioassay of purines.

  11. Foster parenting, human imprinting and conventional handling ...

    African Journals Online (AJOL)

    p2492989

    3 School of Animal Biology, Faculty of Natural Agricultural Science, ... reared by foster parents were heavier than human-imprinted chicks, while early .... Moreover, the research was designed as a preliminary study to explore potential benefits.

  12. Distributed feedback imprinted electrospun fiber lasers.

    Science.gov (United States)

    Persano, Luana; Camposeo, Andrea; Del Carro, Pompilio; Fasano, Vito; Moffa, Maria; Manco, Rita; D'Agostino, Stefania; Pisignano, Dario

    2014-10-01

    Imprinted, distributed feedback lasers are demonstrated on individual, active electrospun polymer nanofibers. In addition to advantages related to miniaturization, optical confinement and grating nanopatterning lead to a significant threshold reduction compared to conventional thin-film lasers. The possibility of imprinting arbitrary photonic crystal geometries on electrospun lasing nanofibers opens new opportunities for realizing optical circuits and chips. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. MOLECULAR IMPRINTED POLYMERS--Novel Polymer Adsorbents

    Institute of Scientific and Technical Information of China (English)

    LI Haitao; XU Mancai; SHI Zuoqing; HE Binglin

    2001-01-01

    Molecular imprinted polymers (MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules. These novel functional polymers have promised potential applications in racemic resolution, sensor, chromatography, adsorptive separation and other fields. This review exhibits the approach for preparing MIPs, the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs. The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.

  14. Molecularly Imprinted Polymers: Present and Future Prospective

    Directory of Open Access Journals (Sweden)

    Giuseppe Vasapollo

    2011-09-01

    Full Text Available Molecular Imprinting Technology (MIT is a technique to design artificial receptors with a predetermined selectivity and specificity for a given analyte, which can be used as ideal materials in various application fields. Molecularly Imprinted Polymers (MIPs, the polymeric matrices obtained using the imprinting technology, are robust molecular recognition elements able to mimic natural recognition entities, such as antibodies and biological receptors, useful to separate and analyze complicated samples such as biological fluids and environmental samples. The scope of this review is to provide a general overview on MIPs field discussing first general aspects in MIP preparation and then dealing with various application aspects. This review aims to outline the molecularly imprinted process and present a summary of principal application fields of molecularly imprinted polymers, focusing on chemical sensing, separation science, drug delivery and catalysis. Some significant aspects about preparation and application of the molecular imprinting polymers with examples taken from the recent literature will be discussed. Theoretical and experimental parameters for MIPs design in terms of the interaction between template and polymer functionalities will be considered and synthesis methods for the improvement of MIP recognition properties will also be presented.

  15. Molecular Imprinting Techniques Used for the Preparation of Biosensors

    Directory of Open Access Journals (Sweden)

    Gizem Ertürk

    2017-02-01

    Full Text Available Molecular imprinting is the technology of creating artificial recognition sites in polymeric matrices which are complementary to the template in their size, shape and spatial arrangement of the functional groups. Molecularly imprinted polymers (MIPs and their incorporation with various transducer platforms are among the most promising approaches for detection of several analytes. There are a variety of molecular imprinting techniques used for the preparation of biomimetic sensors including bulk imprinting, surface imprinting (soft lithography, template immobilization, grafting, emulsion polymerization and epitope imprinting. This chapter presents an overview of all of these techniques with examples from particular publications.

  16. Transcriptional Truncation of the Long Coding Imprinted Gene Usp29.

    Directory of Open Access Journals (Sweden)

    Hongzhi He

    Full Text Available Usp29 (Ubiquitin-specific protease 29 is a paternally expressed gene located upstream of another imprinted gene Peg3. In the current study, the transcription of this long coding gene spanning a 250-kb genomic distance was truncated using a knockin allele. According to the results, paternal transmission of the mutant allele resulted in reduced body and litter sizes whereas the maternal transmission caused no obvious effects. In the paternal mutant, the expression levels of Usp29 were reduced to 14-18% level of the wild-type littermates due to the Poly-A signal included in the knockin cassette. Expression analyses further revealed an unusual female-specific up-regulation of the adjacent imprinted gene Zfp264 in the mutant. Consistent with this, the promoter of Zfp264 was hypomethylated only in the female mutant. Interestingly, this female-specific hypomethylation by the knockin allele was not detected in the offspring of an interspecific crossing, indicating its sensitivity to genetic background. Overall, the results suggest that the transcription of Usp29 may be involved in DNA methylation setting of Zfp264 promoter in a sex-specific manner.

  17. Epigenetic alteration of imprinted genes during neural differentiation of germline-derived pluripotent stem cells.

    Science.gov (United States)

    Lee, Hye Jeong; Choi, Na Young; Lee, Seung-Won; Ko, Kisung; Hwang, Tae Sook; Han, Dong Wook; Lim, Jisun; Schöler, Hans R; Ko, Kinarm

    2016-03-01

    Spermatogonial stem cells (SSCs), which are unipotent stem cells in the testes that give rise to sperm, can be converted into germline-derived pluripotent stem (gPS) by self-induction. The androgenetic imprinting pattern of SSCs is maintained even after their reprogramming into gPS cells. In this study, we used an in vitro neural differentiation model to investigate whether the imprinting patterns are maintained or altered during differentiation. The androgenetic patterns of H19, Snrpn, and Mest were maintained even after differentiation of gPS cells into NSCs (gPS-NSCs), whereas the fully unmethylated status of Ndn in SSCs was altered to somatic patterns in gPS cells and gPS-NSCs. Thus, our study demonstrates epigenetic alteration of genomic imprinting during the induction of pluripotency in SSCs and neural differentiation, suggesting that gPS-NSCs can be a useful model to study the roles of imprinted genes in brain development and human neurodevelopmental disorders.

  18. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Zhenzhong Guo

    2016-10-01

    Full Text Available The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclusion and future expectations are described herein.

  19. Molecularly imprinted polymers for biomedical and biotechnological applications

    Science.gov (United States)

    Dmitrienko, E. V.; Pyshnaya, I. A.; Martyanov, O. N.; Pyshnyi, D. V.

    2016-05-01

    This survey covers main advances in the preparation and application of molecularly imprinted polymers which are capable of specific recognition of biologically active compounds. The principles underlying the production of highly efficient and template-specific molecularly imprinted polymers are discussed. The focus is on the imprinting of highly structured macromolecular and supramolecular templates. The existing and potential applications of molecularly imprinted polymers in various fields of chemistry and molecular biology are considered. The bibliography includes 261 references.

  20. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    OpenAIRE

    Zhenzhong Guo; Anca Florea; Mengjuan Jiang; Yong Mei; Weiying Zhang; Aidong Zhang; Robert Săndulescu; Nicole Jaffrezic-Renault

    2016-01-01

    The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF) for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclu...

  1. Computational Insights on Sulfonamide Imprinted Polymers

    Directory of Open Access Journals (Sweden)

    Chartchalerm Isarankura-Na-Ayudhya

    2008-12-01

    Full Text Available Molecular imprinting is one of the most efficient methods for preparing synthetic receptors that possess user defined recognition properties. Despite general success of non-covalent imprinting for a large variety of templates, some groups of compounds remain difficult to tackle due to their structural complexity. In this study we investigate preparation of molecularly imprinted polymers that can bind sulfonamide compounds, which represent important drug candidates. Compared to the biological system that utilizes metal coordinated interaction, the imprinted polymer provided pronounced selectivity when hydrogen bond interaction was employed in an organic solvent. Computer simulation of the interaction between the sulfonamide template and functional monomers pointed out that although methacrylic acid had strong interaction energy with the template, it also possessed high non-specific interaction with the solvent molecules of tetrahydrofuran as well as being prone to self-complexation. On the other hand, 1-vinyl-imidazole was suitable for imprinting sulfonamides as it did not cross-react with the solvent molecules or engage in self-complexation structures.

  2. Computational insights on sulfonamide imprinted polymers.

    Science.gov (United States)

    Isarankura-Na-Ayudhya, Chartchalerm; Nantasenamat, Chanin; Buraparuangsang, Prasit; Piacham, Theeraphon; Ye, Lei; Bülow, Leif; Prachayasittikul, Virapong

    2008-12-10

    Molecular imprinting is one of the most efficient methods for preparing synthetic receptors that possess user defined recognition properties. Despite general success of non-covalent imprinting for a large variety of templates, some groups of compounds remain difficult to tackle due to their structural complexity. In this study we investigate preparation of molecularly imprinted polymers that can bind sulfonamide compounds, which represent important drug candidates. Compared to the biological system that utilizes metal coordinated interaction, the imprinted polymer provided pronounced selectivity when hydrogen bond interaction was employed in an organic solvent. Computer simulation of the interaction between the sulfonamide template and functional monomers pointed out that although methacrylic acid had strong interaction energy with the template, it also possessed high non-specific interaction with the solvent molecules of tetrahydrofuran as well as being prone to self-complexation. On the other hand, 1-vinyl-imidazole was suitable for imprinting sulfonamides as it did not cross-react with the solvent molecules or engage in self-complexation structures.

  3. Dynamic assembly of molecularly imprinted polymer nanoparticles.

    Science.gov (United States)

    Gong, Haiyue; Hajizadeh, Solmaz; Jiang, Lingdong; Ma, Huiting; Ye, Lei

    2017-09-11

    Manipulation of specific binding and recycling of materials are two important aspects for practical applications of molecularly imprinted polymers. In this work, we developed a new approach to control the dynamic assembly of molecularly imprinted nanoparticles by surface functionalization. Molecularly imprinted polymer nanoparticles with a well-controlled core-shell structure were synthesized using precipitation polymerization. The specific binding sites were created in the core during the first step imprinting reaction. In the second polymerization step, epoxide groups were introduced into the particle shell to act asan intermediate linker to immobilize phenylboronic acids, as well as to introduce cis-diol structures on surface. The imprinted polymer nanoparticles modified with boronic acid and cis-diol structures maintained high molecular binding specificity, and the nanoparticles could be induced to form dynamic particle aggregation that responded to pH variation and chemical stimuli. The possibility of modulating molecular binding and nanoparticle assembly in a mutually independent fashion can be exploited in a number of applications where repeated use of precious nanoparticles is needed. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Imprint cytology: A boon in tissue diagnosis

    Directory of Open Access Journals (Sweden)

    Charusheela Rajesh Gore

    2017-01-01

    Full Text Available Background: The technique of imprint cytology has provided great impetus to cytodiagnosis due to its simplicity, cost effectiveness, rapid results. It plays a significant role in the rapid diagnosis of the lesions. Objectives: To analyze the sensitivity and specificity of imprint cytology and thereby to evaluate its diagnostic utility. Materials and Methods: The prospective study was carried out in a tertiary care hospital. It included 105 cases. Both benign and malignant lesions from different organ systems were included in the study. Various techniques like touch imprints scrape cytology and squash preparations were used according to the nature of tissue sample. The cytodiagnosis was correlated with histopathological (HP diagnosis to evaluate the sensitivity and specificity of imprint cytology. Results: Maximum lesions were of central nervous system (25.7% followed by breast, head, and neck. Imprint cytology diagnosis had sensitivity of 95.5% with 100% specificity for detection of benign and malignant lesions. Overall accuracy of detecting type of lesion was 98.1%. Total discordance with HP diagnosis was found in 1.9% of cases. Conclusion: The use of smear technique in intraoperative diagnosis provides a rapid and efficient means of pathological assessment which in experienced hand, is capable of obtaining a high degree of accuracy. Its use is highly recommended routinely.

  5. Metal films with imprinted nanostructures by template stripping

    DEFF Research Database (Denmark)

    Eriksen, René Lynge; Pors, Anders; Dreier, Jes

    We present a novel template stripping procedure for fabricating metal films with imprinted nanostructures. The basic idea is to deposit a gold film onto a nano-structured substrate and subsequently strip the film from the substrate surface thereby revealing imprinted nanostructures in the film...... result is a thin gold film with imprinted nano-cavities....

  6. Phase-imprinted multiphoton subradiant states

    Science.gov (United States)

    Jen, H. H.

    2017-08-01

    We propose to generate the multiphoton subradiant states and investigate their fluorescences in an array of two-level atoms. These multiphoton states are created initially from the timed Dicke states. Then we can use either a Zeeman or Stark field gradient pulse to imprint linearly increasing phases on the atoms, and this phase-imprinting process unitarily evolves the system to the multiphoton subradiant states. The fluorescence engages a long-range dipole-dipole interaction which originates from a system-reservoir coupling in the dissipation. We locate some of the subradiant multiphoton states from the eigenmodes and show that an optically thick atomic array is best for the preparation of the state with the most reduced decay rate. This phase-imprinting process enables quantum-state engineering of the multiphoton subradiant states and realizes a potential quantum storage of the photonic qubits in the two-level atoms.

  7. Molecular imprinted polymers as drug delivery vehicles.

    Science.gov (United States)

    Zaidi, Shabi Abbas

    2016-09-01

    This review is aimed to discuss the molecular imprinted polymer (MIP)-based drug delivery systems (DDS). Molecular imprinted polymers have proved to possess the potential and also as a suitable material in several areas over a long period of time. However, only recently it has been employed for pharmaceuticals and biomedical applications, particularly as drug delivery vehicles due to properties including selective recognition generated from imprinting the desired analyte, favorable in harsh experimental conditions, and feedback-controlled recognitive drug release. Hence, this review will discuss their synthesis, the reason they are selected as drug delivery vehicles and for their applications in several drug administration routes (i.e. transdermal, ocular and gastrointestinal or stimuli-reactive routes).

  8. Tet-mediated imprinting erasure in H19 locus following reprogramming of spermatogonial stem cells to induced pluripotent stem cells.

    Science.gov (United States)

    Bermejo-Álvarez, P; Ramos-Ibeas, P; Park, K E; Powell, A P; Vansandt, L; Derek, Bickhart; Ramirez, M A; Gutiérrez-Adán, A; Telugu, B P

    2015-09-02

    Selective methylation of CpG islands at imprinting control regions (ICR) determines the monoparental expression of a subset of genes. Currently, it is unclear whether artificial reprogramming induced by the expression of Yamanaka factors disrupts these marks and whether cell type of origin affects the dynamics of reprogramming. In this study, spermatogonial stem cells (SSC) that harbor paternalized imprinting marks, and fibroblasts were reprogrammed to iPSC (SSCiPSC and fiPSC). The SSCiPSC were able to form teratomas and generated chimeras with a higher skin chimerism than those derived from fiPSC. RNA-seq revealed extensive reprogramming at the transcriptional level with 8124 genes differentially expressed between SSC and SSCiPSC and only 490 between SSCiPSC and fiPSC. Likewise, reprogramming of SSC affected 26 of 41 imprinting gene clusters known in the mouse genome. A closer look at H19 ICR revealed complete erasure in SSCiPSC in contrast to fiPSC. Imprinting erasure in SSCiPSC was maintained even after in vivo differentiation into teratomas. Reprogramming of SSC from Tet1 and Tet2 double knockout mice however lacked demethylation of H19 ICR. These results suggest that imprinting erasure during reprogramming depends on the epigenetic landscape of the precursor cell and is mediated by TETs at the H19 locus.

  9. Neurodevelopmental consequences in offspring of mothers with preeclampsia during pregnancy: underlying biological mechanism via imprinting genes.

    Science.gov (United States)

    Nomura, Yoko; John, Rosalind M; Janssen, Anna Bugge; Davey, Charles; Finik, Jackie; Buthmann, Jessica; Glover, Vivette; Lambertini, Luca

    2017-06-01

    Preeclampsia is known to be a leading cause of mortality and morbidity among mothers and their infants. Approximately 3-8% of all pregnancies in the US are complicated by preeclampsia and another 5-7% by hypertensive symptoms. However, less is known about its long-term influence on infant neurobehavioral development. The current review attempts to demonstrate new evidence for imprinting gene dysregulation caused by hypertension, which may explain the link between maternal preeclampsia and neurocognitive dysregulation in offspring. Pub Med and Web of Science databases were searched using the terms "preeclampsia," "gestational hypertension," "imprinting genes," "imprinting dysregulation," and "epigenetic modification," in order to review the evidence demonstrating associations between preeclampsia and suboptimal child neurodevelopment, and suggest dysregulation of placental genomic imprinting as a potential underlying mechanism. The high mortality and morbidity among mothers and fetuses due to preeclampsia is well known, but there is little research on the long-term biological consequences of preeclampsia and resulting hypoxia on the fetal/child neurodevelopment. In the past decade, accumulating evidence from studies that transcend disciplinary boundaries have begun to show that imprinted genes expressed in the placenta might hold clues for a link between preeclampsia and impaired cognitive neurodevelopment. A sudden onset of maternal hypertension detected by the placenta may result in misguided biological programming of the fetus via changes in the epigenome, resulting in suboptimal infant development. Furthering our understanding of the molecular and cellular mechanisms through which neurodevelopmental trajectories of the fetus/infant are affected by preeclampsia and hypertension will represent an important first step toward preventing adverse neurodevelopment in infants.

  10. Molecularly imprinted polymers for bioanalytical sample preparation.

    Science.gov (United States)

    Gama, Mariana Roberto; Bottoli, Carla Beatriz Grespan

    2017-02-01

    Molecularly imprinted polymers (MIP) are stable polymers with molecular recognition abilities, provided by the presence of a template during their synthesis, and are excellent materials with high selectivity for sample preparation in bioanalytical methods. This short review discusses aspects of MIP preparation and its applications as a sorbent material in pharmaceutical and biomedical analysis. MIP in different extraction configurations, including classical solid-phase extraction, solid-phase microextraction, magnetic molecularly imprinted solid-phase extraction, microextraction by packed sorbent and solid-phase extraction in pipette tips, are used to illustrate the good performance of this type of sorbent for sample preparation procedures of complex matrices, especially prior to bioanalytical approaches.

  11. MOLECULAR IMPRINTED POLYMERS—Novel Polymer Adsorbents

    Institute of Scientific and Technical Information of China (English)

    LIHaitao; XUMancai; 等

    2001-01-01

    Molecular imprinted polymers(MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules,These novel functional polymers have promised potential applications in racemic resolution,sensor,chromatography,adsorptive separation and other fields.This review exhibits the approach for preparing MIPs,the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs.The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.

  12. Improvement of DNA recognition through molecular imprinting: hybrid oligomer imprinted polymeric nanoparticles (oligoMIP NPs)

    National Research Council Canada - National Science Library

    Brahmbhatt, H; Poma, A; Pendergraff, H M; Watts, J K; Turner, N W

    2016-01-01

    .... Molecularly imprinted polymers (MIPs) are cost-effective "smart" polymeric materials capable of antibody-like detection, but characterized by superior robustness and the ability to work in extreme environmental...

  13. Thermochemical study of amino acid imprinted polymer films.

    Science.gov (United States)

    Chai, Ziyi; BelBruno, Joseph J

    2015-11-01

    Molecularly imprinted polymers provide an alternative to traditional methods of amino acid analysis. The imprinted polymers are more robust and significantly less expensive than, for example, ELISA analysis. Amino acid imprinted nylon-6 thin films were studied by differential scanning calorimetry and scanning electron microscopy. Endothermic peaks were observed for imprinted films at temperatures higher than that for pure nylon, indicating the formation of a more-ordered, hydrogen bonded polymer. Removal of the amino acid from the imprinted film resulted in reversion to the peak observed for pure nylon-6. Additives, β-cyclodextrin and multiwalled carbon nanotubes, were added to the imprinted polymer solutions as a means to increase the porosity of the films. These studies resulted in alternative morphologies and calorimetric results that provide additional functionalities and applications for imprinted polymers.

  14. Molecular recognition effects in atomistic models of imprinted polymers.

    Science.gov (United States)

    Dourado, Eduardo M A; Herdes, Carmelo; van Tassel, Paul R; Sarkisov, Lev

    2011-01-01

    In this article we present a model for molecularly imprinted polymers, which considers both complexation processes in the pre-polymerization mixture and adsorption in the imprinted structures within a single consistent framework. As a case study we investigate MAA/EGDMA polymers imprinted with pyrazine and pyrimidine. A polymer imprinted with pyrazine shows substantial selectivity towards pyrazine over pyrimidine, thus exhibiting molecular recognition, whereas the pyrimidine imprinted structure shows no preferential adsorption of the template. Binding sites responsible for the molecular recognition of pyrazine involve one MAA molecule and one EGDMA molecule, forming associations with the two functional groups of the pyrazine molecule. Presence of these specific sites in the pyrazine imprinted system and lack of the analogous sites in the pyrimidine imprinted system is directly linked to the complexation processes in the pre-polymerization solution. These processes are quite different for pyrazine and pyrimidine as a result of both enthalpic and entropic effects.

  15. Molecular Recognition Effects in Atomistic Models of Imprinted Polymers

    Directory of Open Access Journals (Sweden)

    Carmelo Herdes

    2011-07-01

    Full Text Available In this article we present a model for molecularly imprinted polymers, which considers both complexation processes in the pre-polymerization mixture and adsorption in the imprinted structures within a single consistent framework. As a case study we investigate MAA/EGDMA polymers imprinted with pyrazine and pyrimidine. A polymer imprinted with pyrazine shows substantial selectivity towards pyrazine over pyrimidine, thus exhibiting molecular recognition, whereas the pyrimidine imprinted structure shows no preferential adsorption of the template. Binding sites responsible for the molecular recognition of pyrazine involve one MAA molecule and one EGDMA molecule, forming associations with the two functional groups of the pyrazine molecule. Presence of these specific sites in the pyrazine imprinted system and lack of the analogous sites in the pyrimidine imprinted system is directly linked to the complexation processes in the pre-polymerization solution. These processes are quite different for pyrazine and pyrimidine as a result of both enthalpic and entropic effects.

  16. Genomic understanding of dinoflagellates.

    Science.gov (United States)

    Lin, Senjie

    2011-01-01

    The phylum of dinoflagellates is characterized by many unusual and interesting genomic and physiological features, the imprint of which, in its immense genome, remains elusive. Much novel understanding has been achieved in the last decade on various aspects of dinoflagellate biology, but most remarkably about the structure, expression pattern and epigenetic modification of protein-coding genes in the nuclear and organellar genomes. Major findings include: 1) the great diversity of dinoflagellates, especially at the base of the dinoflagellate tree of life; 2) mini-circularization of the genomes of typical dinoflagellate plastids (with three membranes, chlorophylls a, c1 and c2, and carotenoid peridinin), the scrambled mitochondrial genome and the extensive mRNA editing occurring in both systems; 3) ubiquitous spliced leader trans-splicing of nuclear-encoded mRNA and demonstrated potential as a novel tool for studying dinoflagellate transcriptomes in mixed cultures and natural assemblages; 4) existence and expression of histones and other nucleosomal proteins; 5) a ribosomal protein set expected of typical eukaryotes; 6) genetic potential of non-photosynthetic solar energy utilization via proton-pump rhodopsin; 7) gene candidates in the toxin synthesis pathways; and 8) evidence of a highly redundant, high gene number and highly recombined genome. Despite this progress, much more work awaits genome-wide transcriptome and whole genome sequencing in order to unfold the molecular mechanisms underlying the numerous mysterious attributes of dinoflagellates.

  17. Imprinting Technology in Electrochemical Biomimetic Sensors

    Directory of Open Access Journals (Sweden)

    Manuela F. Frasco

    2017-03-01

    Full Text Available Biosensors are a promising tool offering the possibility of low cost and fast analytical screening in point-of-care diagnostics and for on-site detection in the field. Most biosensors in routine use ensure their selectivity/specificity by including natural receptors as biorecognition element. These materials are however too expensive and hard to obtain for every biochemical molecule of interest in environmental and clinical practice. Molecularly imprinted polymers have emerged through time as an alternative to natural antibodies in biosensors. In theory, these materials are stable and robust, presenting much higher capacity to resist to harsher conditions of pH, temperature, pressure or organic solvents. In addition, these synthetic materials are much cheaper than their natural counterparts while offering equivalent affinity and sensitivity in the molecular recognition of the target analyte. Imprinting technology and biosensors have met quite recently, relying mostly on electrochemical detection and enabling a direct reading of different analytes, while promoting significant advances in various fields of use. Thus, this review encompasses such developments and describes a general overview for building promising biomimetic materials as biorecognition elements in electrochemical sensors. It includes different molecular imprinting strategies such as the choice of polymer material, imprinting methodology and assembly on the transduction platform. Their interface with the most recent nanostructured supports acting as standard conductive materials within electrochemical biomimetic sensors is pointed out.

  18. Plastic Antibodies: Molecular Recognition with Imprinted Polymers

    Science.gov (United States)

    Rushton, Gregory T.; Furmanski, Brian; Shimizu, Ken D.

    2005-01-01

    Synthetic polymers are prepared and tested in a study for their molecular recognition properties of an adenine derivative, ethyl adenine-9-acetate (EA9A), within two laboratory periods. The procedure introduces undergraduate chemistry students to noncovalent molecular imprinting as well as the analytical techniques for assessing their recognition…

  19. Surface Plasmon Resonance Studies on Molecular Imprinting

    Directory of Open Access Journals (Sweden)

    Baoping Lin

    2002-01-01

    Full Text Available The molecular imprinted polymer (MIP members were fabricated with the print molecule L-phenylalanine ethyl ester. The elution and adsorption procedures were investigated by surface plasmon resonance in situ. The changes of refractive angle during elution procedure suggest that the MIP is prepared on the base of the non-covalent interactions. This MIP member sensor can achieve enantioselective recognition.

  20. Cell shape recognition by colloidal cell imprints

    NARCIS (Netherlands)

    Borovička, Josef; Stoyanov, S.D.; Paunov, V.N.

    2015-01-01

    The results presented in this study are aimed at the theoretical estimate of the interactions between a spherical microbial cell and the colloidal cell imprints in terms of the Derjaguin, Landau, Vervey, and Overbeek (DLVO) surface forces. We adapted the Derjaguin approximation to take into accou

  1. Molecularly imprinted polymers for some reactive dyes.

    Science.gov (United States)

    Okutucu, Burcu; Akkaya, Alper; Pazarlioglu, Nurdan Kasikara

    2010-01-01

    Depending upon their structure, azo- and anthraquinonic dyes are the two major classes and together represent 90% of all organic colorants. Adsorption of dye molecules onto a sorbent can be an effective, low-cost method of color removal. Most of the techniques used for removal of dyes are of high production cost, and the regeneration also makes them uneconomical. There is much interest in the development of cheaper and effective newer materials for use as adsorbents. Molecular imprinting is a new kind of materials that can be alternative adsorbents. In this study, molecularly imprinted polymers of three textile dyes (Cibacron Orange P-4R, Cibacron Red P-4B, Cibacron Black PSG) were prepared. Methacrylic acid was used as a monomer for red and orange dyes and acrylamide was used for black dye. Methanol:acetonitrile was used as a porogen. The selective recognition ability of the molecularly imprinted polymers was studied by an equilibrium-adsorption batch method. The adsorption data are for Cibacron Black PSG 65% and nonimprinted polymer (NIP) 25%; Cibacron Red P-4B 72% and NIP 18%; and Cibacron Orange P-4R 45% and NIP 10%, respectively. Dye-imprinted polymers were used as a solid-phase extraction material for selective adsorption from wastewater of textile factory.

  2. Molecular Imprinting Applications in Forensic Science.

    Science.gov (United States)

    Yılmaz, Erkut; Garipcan, Bora; Patra, Hirak K; Uzun, Lokman

    2017-03-28

    Producing molecular imprinting-based materials has received increasing attention due to recognition selectivity, stability, cast effectiveness, and ease of production in various forms for a wide range of applications. The molecular imprinting technique has a variety of applications in the areas of the food industry, environmental monitoring, and medicine for diverse purposes like sample pretreatment, sensing, and separation/purification. A versatile usage, stability and recognition capabilities also make them perfect candidates for use in forensic sciences. Forensic science is a demanding area and there is a growing interest in molecularly imprinted polymers (MIPs) in this field. In this review, recent molecular imprinting applications in the related areas of forensic sciences are discussed while considering the literature of last two decades. Not only direct forensic applications but also studies of possible forensic value were taken into account like illicit drugs, banned sport drugs, effective toxins and chemical warfare agents in a review of over 100 articles. The literature was classified according to targets, material shapes, production strategies, detection method, and instrumentation. We aimed to summarize the current applications of MIPs in forensic science and put forth a projection of their potential uses as promising alternatives for benchmark competitors.

  3. Imprinting Technology in Electrochemical Biomimetic Sensors.

    Science.gov (United States)

    Frasco, Manuela F; Truta, Liliana A A N A; Sales, M Goreti F; Moreira, Felismina T C

    2017-03-06

    Biosensors are a promising tool offering the possibility of low cost and fast analytical screening in point-of-care diagnostics and for on-site detection in the field. Most biosensors in routine use ensure their selectivity/specificity by including natural receptors as biorecognition element. These materials are however too expensive and hard to obtain for every biochemical molecule of interest in environmental and clinical practice. Molecularly imprinted polymers have emerged through time as an alternative to natural antibodies in biosensors. In theory, these materials are stable and robust, presenting much higher capacity to resist to harsher conditions of pH, temperature, pressure or organic solvents. In addition, these synthetic materials are much cheaper than their natural counterparts while offering equivalent affinity and sensitivity in the molecular recognition of the target analyte. Imprinting technology and biosensors have met quite recently, relying mostly on electrochemical detection and enabling a direct reading of different analytes, while promoting significant advances in various fields of use. Thus, this review encompasses such developments and describes a general overview for building promising biomimetic materials as biorecognition elements in electrochemical sensors. It includes different molecular imprinting strategies such as the choice of polymer material, imprinting methodology and assembly on the transduction platform. Their interface with the most recent nanostructured supports acting as standard conductive materials within electrochemical biomimetic sensors is pointed out.

  4. Genomic imprinting and maternal effect genes in haplodiploid sex determination

    NARCIS (Netherlands)

    van de Zande, L.; Verhulst, E. C.

    2014-01-01

    The research into the Drosophila melanogaster sex-determining system has been at the basis of all further research on insect sex determination. This further research has made it clear that, for most insect species, the presence of sufficient functional Transformer (TRA) protein in the early

  5. Angelman syndrome: insights into genomic imprinting and neurodevelopmental phenotypes.

    Science.gov (United States)

    Mabb, Angela M; Judson, Matthew C; Zylka, Mark J; Philpot, Benjamin D

    2011-06-01

    Angelman syndrome (AS) is a severe genetic disorder caused by mutations or deletions of the maternally inherited UBE3A gene. UBE3A encodes an E3 ubiquitin ligase that is expressed biallelically in most tissues but is maternally expressed in almost all neurons. In this review, we describe recent advances in understanding the expression and function of UBE3A in the brain and the etiology of AS. We highlight current AS model systems, epigenetic mechanisms of UBE3A regulation, and the identification of potential UBE3A substrates in the brain. In the process, we identify major gaps in our knowledge that, if bridged, could move us closer to identifying treatments for this debilitating neurodevelopmental disorder. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Genomic imprinting and maternal effect genes in haplodiploid sex determination

    NARCIS (Netherlands)

    van de Zande, L.; Verhulst, E. C.

    2014-01-01

    The research into the Drosophila melanogaster sex-determining system has been at the basis of all further research on insect sex determination. This further research has made it clear that, for most insect species, the presence of sufficient functional Transformer (TRA) protein in the early embryoni

  7. CTCF-dependent chromatin bias constitutes transient epigenetic memory of the mother at the H19-Igf2 imprinting control region in prospermatogonia.

    Directory of Open Access Journals (Sweden)

    Dong-Hoon Lee

    2010-11-01

    Full Text Available Genomic imprints-parental allele-specific DNA methylation marks at the differentially methylated regions (DMRs of imprinted genes-are erased and reestablished in germ cells according to the individual's sex. Imprint establishment at paternally methylated germ line DMRs occurs in fetal male germ cells. In prospermatogonia, the two unmethylated alleles exhibit different rates of de novo methylation at the H19/Igf2 imprinting control region (ICR depending on parental origin. We investigated the nature of this epigenetic memory using bisulfite sequencing and allele-specific ChIP-SNuPE assays. We found that the chromatin composition in fetal germ cells was biased at the ICR between the two alleles with the maternally inherited allele exhibiting more H3K4me3 and less H3K9me3 than the paternally inherited allele. We determined genetically that the chromatin bias, and also the delayed methylation establishment in the maternal allele, depended on functional CTCF insulator binding sites in the ICR. Our data suggest that, in primordial germ cells, maternally inherited allele-specific CTCF binding sets up allele-specific chromatin differences at the ICR. The erasure of these allele-specific chromatin marks is not complete before the process of de novo methylation imprint establishment begins. CTCF-dependent allele-specific chromatin composition imposes a maternal allele-specific delay on de novo methylation imprint establishment at the H19/Igf2 ICR in prospermatogonia.

  8. CTCF-dependent chromatin bias constitutes transient epigenetic memory of the mother at the H19-Igf2 imprinting control region in prospermatogonia.

    Directory of Open Access Journals (Sweden)

    Dong-Hoon Lee

    2010-11-01

    Full Text Available Genomic imprints-parental allele-specific DNA methylation marks at the differentially methylated regions (DMRs of imprinted genes-are erased and reestablished in germ cells according to the individual's sex. Imprint establishment at paternally methylated germ line DMRs occurs in fetal male germ cells. In prospermatogonia, the two unmethylated alleles exhibit different rates of de novo methylation at the H19/Igf2 imprinting control region (ICR depending on parental origin. We investigated the nature of this epigenetic memory using bisulfite sequencing and allele-specific ChIP-SNuPE assays. We found that the chromatin composition in fetal germ cells was biased at the ICR between the two alleles with the maternally inherited allele exhibiting more H3K4me3 and less H3K9me3 than the paternally inherited allele. We determined genetically that the chromatin bias, and also the delayed methylation establishment in the maternal allele, depended on functional CTCF insulator binding sites in the ICR. Our data suggest that, in primordial germ cells, maternally inherited allele-specific CTCF binding sets up allele-specific chromatin differences at the ICR. The erasure of these allele-specific chromatin marks is not complete before the process of de novo methylation imprint establishment begins. CTCF-dependent allele-specific chromatin composition imposes a maternal allele-specific delay on de novo methylation imprint establishment at the H19/Igf2 ICR in prospermatogonia.

  9. A Path to Soluble Molecularly Imprinted Polymers

    Directory of Open Access Journals (Sweden)

    Abhilasha Verma

    2011-12-01

    Full Text Available Molecular imprinting is a technique for making a selective binding site for a specific chemical. The technique involves building a polymeric scaffold of molecular complements containing the target molecule. Subsequent removal of the target leaves a cavity with a structural “memory” of the target. Molecularly imprinted polymers (MIPs can be employed as selective adsorbents of specific molecules or molecular functional groups. In addition, sensors for specific molecules can be made using optical transduction through lumiphores residing in the imprinted site. We have found that the use of metal ions as chromophores can improve selectivity due to selective complex formation. The combination of molecular imprinting and spectroscopic selectivity can result in sensors that are highly sensitive and nearly immune to interferences. A weakness of conventional MIPs with regard to processing is the insolubility of crosslinked polymers. Traditional MIPs are prepared either as monoliths and ground into powders or are prepared in situ on a support. This limits the applicability of MIPs by imposing tedious or difficult processes for their inclusion in devices. The size of the particles hinders diffusion and slows response. These weaknesses could be avoided if a means were found to prepare individual macromolecules with crosslinked binding sites with soluble linear polymeric arms. This process has been made possible by controlled free radical polymerization techniques that can form pseudo-living polymers. Modern techniques of controlled free radical polymerization allow the preparation of block copolymers with potentially crosslinkable substituents in specific locations. The inclusion of crosslinkable mers proximate to the binding complex in the core of a star polymer allows the formation of molecularly imprinted macromolecules that are soluble and processable. Due to the much shorter distance for diffusion, the polymers exhibit rapid responses. This paper

  10. Possible diversifying selection in the imprinted gene, MEDEA, in Arabidopsis.

    Science.gov (United States)

    Miyake, Takashi; Takebayashi, Naoki; Wolf, Diana E

    2009-04-01

    Coevolutionary conflict among imprinted genes that influence traits such as offspring growth may arise when maternal and paternal genomes have different evolutionary optima. This conflict is expected in outcrossing taxa with multiple paternity, but not self-fertilizing taxa. MEDEA (MEA) is an imprinted plant gene that influences seed growth. Disagreement exists regarding the type of selection acting on this gene. We present new data and analyses of sequence diversity of MEA in self-fertilizing and outcrossing Arabidopsis and its relatives, to help clarify the form of selection acting on this gene. Codon-based branch analysis among taxa (PAML) suggests that selection on the coding region is changing over time, and nonsynonymous substitution is elevated in at least one outcrossing branch. Codon-based analysis of diversity within outcrossing Arabidopsis lyrata ssp. petraea (OmegaMap) suggests that diversifying selection is acting on a portion of the gene, to cause elevated nonsynonymous polymorphism. Providing further support for balancing selection in A. lyrata, Hudson, Kreitman and Aguadé analysis indicates that diversity/divergence at silent sites in the MEA promoter and genic region is elevated relative to reference genes, and there are deviations from the neutral frequency spectrum. This combination of positive selection as well as balancing and diversifying selection in outcrossing lineages is consistent with other genes influence by evolutionary conflict, such as disease resistance genes. Consistent with predictions that conflict would be eliminated in self-fertilizing taxa, we found no evidence of positive, balancing, or diversifying selection in A. thaliana promoter or genic region.

  11. On the detection of imprinted quantitative trait loci in experimental crosses of outbred species

    NARCIS (Netherlands)

    Koning, de D.J.; Bovenhuis, H.; Arendonk, van J.A.M.

    2002-01-01

    In this article, the quantitative genetic aspects of imprinted genes and statistical properties of methods to detect imprinted QTL are studied. Different models to detect imprinted QTL and to distinguish between imprinted and Mendelian QTL were compared in a simulation study. Mendelian and imprinted

  12. On the detection of imprinting quantitative trait loci in experimental crosses of outbred species

    NARCIS (Netherlands)

    Koning, de D.J.; Bovenhuis, H.; Arendonk, van J.A.M.

    2002-01-01

    In this article, the quantitative genetic aspects of imprinted genes and statistical properties of methods to detect imprinted QTL are studied. Different models to detect imprinted QTL and to distinguish between imprinted and Mendelian QTL were compared in a simulation study. Mendelian and imprinted

  13. NMDA receptor antagonists extend the sensitive period for imprinting.

    Science.gov (United States)

    Parsons, C H; Rogers, L J

    2000-03-01

    Filial imprinting in the domestic chick occurs during a sensitive period of development. The exact timing of this period can vary according to the methods used to measure imprinting. Using our imprinting paradigm, we have shown that normal, dark-reared chicks lose the ability to imprint after the second day post-hatching. Further, we reported that chicks treated 10 h after hatching with a mixture of the noncompetitive NMDA receptor antagonist ketamine (55 mg/kg) and the alpha(2)-adrenergic receptor agonist xylazine (6 mg/kg) were able to imprint on day 8 after hatching, whereas controls treated with saline did not imprint. We now show that the effect of the ketamine-xylazine mixture can be mimicked by treating chicks with ketamine alone or with another noncompetitive NMDA receptor antagonist, MK-801 (5 mg/kg). Treating chicks with a single dose of ketamine (55 mg/kg) or with a single dose of xylazine (6 mg/kg) failed to produce the effect on the sensitive period. However, prolonging the action of ketamine by treating chicks with two doses of ketamine (at 10 and 12 h after hatching) did allow imprinting on day 8. In contrast, prolonging the action of xylazine had no effect on the sensitive period for imprinting. Chicks treated with MK-801 were also able to imprint on day 8. Thus, we have evidence that the NMDA receptor system is involved in the mechanisms that control the sensitive period for imprinting.

  14. A comparison of covalent and non-covalent imprinting strategies for the synthesis of stigmasterol imprinted polymers.

    Science.gov (United States)

    Hashim, Shima N N S; Boysen, Reinhard I; Schwarz, Lachlan J; Danylec, Basil; Hearn, Milton T W

    2014-09-12

    Non-covalent and covalent imprinting strategies have been investigated for the synthesis of stigmasterol imprinted polymers. The synthesized molecularly imprinted polymers (MIPs) were then evaluated for their recognition and selectivity towards stigmasterol via static and dynamic batch-binding assays and their performance measured against control non-imprinted polymers (NIPs). MIPs prepared using the conventional non-covalent imprinting method displayed little to no binding affinity for stigmasterol under various conditions. In contrast, the application of a covalent imprinting approach using the novel post-synthetically cleavable monomer-template composite stigmasteryl-3-O-methacrylate resulted in the fabrication of a MIP that successfully recognized stigmasterol in both organic and partially aqueous environments. The affinity and selectivity of the covalently prepared MIP was enhanced when undertaken in a partially aqueous environment consisting of an acetonitrile/water (9:1, v/v) solvent mixture. These features have been exploited in a molecularly imprinted solid-phase extraction (MISPE) format, wherein the preferential retention of stigmasterol (with an imprint factor of 12) was demonstrated with 99% recovery in comparison to cholesterol (imprint factor of 6) and ergosterol (imprint factor of 4) while in the presence of several closely related steryl analogues.

  15. [Spectroscopic Study of Salbutamol Molecularly Imprinted Polymers].

    Science.gov (United States)

    Ren, Hui-peng; Guan, Yu-yu; Dai, Rong-hua; Liu, Guo-yan; Chai, Chun-yan

    2016-02-01

    In order to solve the problem of on-site rapid detection of salbutamol residues in feed and animal products, and develop a new method of fast detection of salbutamol on the basis of the molecular imprinting technology, this article uses the salbutamol (SAL) working as template molecule, methacrylic acid (MAA) working as functional monomer. On this basis, a new type of core-shell type salbutamol molecularly imprinted polymers were prepared with colloidal gold particles as triggering core. Superficial characteristics of the MIPs and the related compounds were investigated by ultraviolet (UV) spectra and infrared (IR) spectra, Raman spectra, Scanning electron microscopy (SEM) respectively. The results indicated that a stable hydrogen bonding complex has been formed between the carboxyl groups of SAL and MA with a matching ratio of 1:1. The complex can be easily eluted by the reagent containing hydrogen bonding. The chemical binding constant K reaches -0.245 x 10⁶ L² · mol⁻². The possible binding sites of the hydrogen bonding was formed between the hydrogen atoms of -COOH in MA and the oxygen atoms of C==O in SAL. IR and Raman spectrum showed that, compared with MA, a significant red shift of -OH absorption peak was manifested in MIPs, which proved that SAL as template molecule occurred a specific bond between MA. Red shift of stretching vibration absorption peak of C==O was also detected in the un-eluted MIPs and obvious energy loss happened, which demonstrated a possible binding sites is SAL intramolecular of C==O atom of oxygen. If the hydrogen atoms of -COOH in MA wanted to generate hydrogen bond. However, the shapes of absorption peak of other functional groups including C==C, C==O, and -OH were very similar both in MIPs and NIPs. Specific cavities were formed after the template molecules in MIPs were removed. It was proved by the adsorption experiment that the specific sites in these cavities highly match with the chemical and space structure of SAL

  16. Characterization of molecularly imprinted polymer nanoparticles by photon correlation spectroscopy.

    Science.gov (United States)

    Malm, Björn; Yoshimatsu, Keiichi; Ye, Lei; Krozer, Anatol

    2014-12-01

    We follow template-binding induced aggregation of nanoparticles enantioselectively imprinted against (S)-propranolol, and the non-imprinted ones, using photon correlation spectroscopy (dynamic light scattering). The method requires no separation steps. We have characterized binding of (R,S)-propranolol to the imprinted polymers and determined the degree of non-specificity by comparing the specific binding with the results obtained using non-imprinted nanoparticles. Using (S)-propranolol as a template for binding to (S)-imprinted nanoparticle, and (R)-propranolol as a non-specific control, we have determined range of concentrations where chiral recognition can be observed. By studying aggregation induced by three analytes related to propranolol, atenolol, betaxolol, and 1-amino-3-(naphthalen-1-yloxy)propan-2-ol, we were able to determine which parts of the template are involved in the specific binding, discuss several details of specific adsorption, and the structure of the imprinted site.

  17. A molecular-imprint nanosensor for ultrasensitive detection of proteins

    Science.gov (United States)

    Cai, Dong; Ren, Lu; Zhao, Huaizhou; Xu, Chenjia; Zhang, Lu; Yu, Ying; Wang, Hengzhi; Lan, Yucheng; Roberts, Mary F.; Chuang, Jeffrey H.; Naughton, Michael J.; Ren, Zhifeng; Chiles, Thomas C.

    2010-08-01

    Molecular imprinting is a technique for preparing polymer scaffolds that function as synthetic receptors. Imprinted polymers that can selectively bind organic compounds have proven useful in sensor development. Although creating synthetic molecular-imprinting polymers that recognize proteins remains challenging, nanodevices and nanomaterials show promise in this area. Here, we show that arrays of carbon-nanotube tips with an imprinted non-conducting polymer coating can recognize proteins with subpicogram per litre sensitivity using electrochemical impedance spectroscopy. We have developed molecular-imprinting sensors specific for human ferritin and human papillomavirus derived E7 protein. The molecular-imprinting-based nanosensor can also discriminate between Ca2+-induced conformational changes in calmodulin. This ultrasensitive, label-free electrochemical detection of proteins offers an alternative to biosensors based on biomolecule recognition.

  18. [Werkgartner's muzzle imprint mark--a literature study].

    Science.gov (United States)

    Geserick, Gunther; Vendura, Klaus; Wirth, Ingo

    2009-01-01

    Since Werkgartner described and correctly interpreted the muzzle imprint mark around the gunshot entrance wound in 1922, this finding has been generally accepted as a sign of a contact shot. In further studies, it could finally be clarified that the muzzle imprint mark is caused by the expansive power of the powder gases with pressure on and abrasion of the skin at the muzzle (weapon imprint). Its shape depends on the firearm, the ammunition and the anatomical conditions, but does not require a bullet. Examinations under a magnifying glass microscope and histological investigations can complete the macroscopic findings. Occasionally, the muzzle imprint mark requires a certain "drying period" in order to become clearly visible. In rare cases, muzzle imprint marks also form on textiles perforated by the projectile. Characteristically shaped muzzled imprint marks can provide clues to the type of the firearm and its position at the time of discharge.

  19. Mapping of imprinted quantitative trait loci using immortalized F2 populations.

    Directory of Open Access Journals (Sweden)

    Yongxian Wen

    Full Text Available Mapping of imprinted quantitative trait loci (iQTLs is helpful for understanding the effects of genomic imprinting on complex traits in animals and plants. At present, the experimental designs and corresponding statistical methods having been proposed for iQTL mapping are all based on temporary populations including F2 and BC1, which can be used only once and suffer some other shortcomings respectively. In this paper, we propose a framework for iQTL mapping, including methods of interval mapping (IM and composite interval mapping (CIM based on conventional low-density genetic maps and point mapping (PM and composite point mapping (CPM based on ultrahigh-density genetic maps, using an immortalized F2 (imF2 population generated by random crosses between recombinant inbred lines or doubled haploid lines. We demonstrate by simulations that imF2 populations are very desirable and the proposed statistical methods (especially CIM and CPM are very powerful for iQTL mapping, with which the imprinting effects as well as the additive and dominance effects of iQTLs can be unbiasedly estimated.

  20. Preparation of imprinted monolithic column under molecular crowding conditions

    Institute of Scientific and Technical Information of China (English)

    Xiao Xia Li; Xin Liu; Li Hong Bai; Hong Quan Duan; Yan Ping Huang; Zhao Sheng Liu

    2011-01-01

    Molecular crowding is a new concept to obtain molecularly imprinted polymers (MIPs) with greater capacity and selectivity. In this work, molecular crowding agent was firstly applied to the preparation of MIPs monolithic column. A new polymerization system based on molecular crowding surrounding was developed to prepare enrofloxacin-imprinted monolith, which was composed of polystyrene and tetrahydrofuran. The result showed that the monolithic MIPs under molecular crowding conditions presented good molecular recognition for enrofloxacin with an imprinting factor of 3.03.

  1. Development of a Molecularly Imprinted Biomimetic Electrode

    Directory of Open Access Journals (Sweden)

    Evangelyn C. Alocilja

    2007-08-01

    Full Text Available The technique of molecular imprinting produces artificial receptor sites in apolymer that can be used in a biomimetic sensor. This research extends previous studies ofa molecularly imprinted polymer (MIP biomimetic sensor for the small drug theophylline.The presence of theophylline in the biomimetic sensor was monitored by analyzing thepeak currents from cyclic voltammetry experiments. The functional working range of theMIP modified electrode was 2 - 4 mM theophylline. The concentration of theophyllinethat resulted in the best signal was 3 mM. The MIP sensor showed no response to thestructurally related molecule caffeine, and therefore was selective to the target analytetheophylline. This research will provide the foundation for future studies that will result indurable biomimetic sensors that can offer a viable alternative to current sensors.

  2. Gastric mucormycosis: Diagnosis by imprint cytology.

    Science.gov (United States)

    Tathe, Shilpa P; Dani, Aarti A; Chawhan, Sanjay M; Meshram, Saroj A; Randale, Archana A; Raut, Waman K

    2016-10-01

    The fungi in the order of Mucorales commonly target diabetics and other immunocompromised hosts, producing fatal respiratory and or CNS infections. Gastrointestinal mucormycosis is uncommon and seldom diagnosed in living patients due to nonspecific clinical manifestations. We report a case of gastric mucormycosis in an immmunocompetent male patient, diagnosed by imprint cytology-a rare site and a rare setting. To the best of our knowledge, this is only the second report of gastric mucormycosis being diagnosed on cytology. As the disease is rapidly progressive and often fatal, early diagnosis is critical to the patient survival. Imprint cytology or brush cytology is extremely useful for the rapid diagnosis of gastric mucormycosis as these organisms are morphologically distinct. Familiarity with the cytomorphology of these organisms assists in the correct diagnosis of this disease. Diagn. Cytopathol. 2016;44:820-822. © 2016 Wiley Periodicals, Inc.

  3. Bolt Cutter Blade's Imprint in Toolmarks Examination.

    Science.gov (United States)

    Volkov, Nikolai; Finkelstein, Nir; Novoselsky, Yehuda; Tsach, Tsadok

    2015-11-01

    Bolt cutters are known as cutting tools which are used for cutting hard objects and materials, such as padlocks and bars. Bolt cutter blades leave their imprint on the cut objects. When receiving a cut object from a crime scene, forensic toolmarks examiners can determine whether the suspected cutting tool was used in a specific crime or not based on class characteristic marks and individual marks that the bolt cutter blades leave on the cut object. The paper presents preliminary results of a study on ten bolt cutters and suggests a quick preliminary examination-the comparison between the blade thickness and the width of the imprint left by the tool on the cut object. Based on the comparison result, if there is not a match, the examiner can eliminate the feasibility of the use of the suspected cutting tool in a specific crime. This examination simplifies and accelerates the comparison procedure.

  4. Imprinting localized plasmons for enhanced solar cells.

    Science.gov (United States)

    Dunbar, Ricky B; Pfadler, Thomas; Lal, Niraj N; Baumberg, Jeremy J; Schmidt-Mende, Lukas

    2012-09-28

    Imprinted silver nanovoid arrays are investigated via angle-resolved reflectometry to demonstrate their suitability for plasmonic light trapping. Both wavelength- and subwavelength-scale nanovoids are imprinted into standard solar cell architectures to achieve nanostructured metallic electrodes which provide enhanced absorption for improving solar cell performance. The technique is versatile, low-cost and scalable and can be applied to a wide range of organic semiconductors. Absorption features which are independent of incident polarization and weakly dependent on incident angle reveal localized plasmonic modes at the structured interface. Metallic nanostructure-PCPDTBT:PCBM samples demonstrate absorption enhancements of up to 40%. The structured interface provides light trapping, which boosts absorption at wavelengths where the semiconductors absorb poorly.

  5. Imprinting: seeing food and eating it.

    Science.gov (United States)

    Healy, Susan D

    2006-07-11

    A recent study has found that although, ordinarily, cuttlefish hatchlings prefer shrimp-like prey, when visually exposed to crabs in the first hours of day one, they later prefer crabs to shrimps. As the development of this preference occurs during a short sensitive phase, does not depend on food ingestion and is long lasting, it fulfils all the criteria for imprinting, a phenomenon more usually associated with vertebrates and social learning.

  6. Nanoscale molecularly imprinted polymers and method thereof

    Science.gov (United States)

    Hart, Bradley R.; Talley, Chad E.

    2008-06-10

    Nanoscale molecularly imprinted polymers (MIP) having polymer features wherein the size, shape and position are predetermined can be fabricated using an xy piezo stage mounted on an inverted microscope and a laser. Using an AMF controller, a solution containing polymer precursors and a photo initiator are positioned on the xy piezo and hit with a laser beam. The thickness of the polymeric features can be varied from a few nanometers to over a micron.

  7. Synthesis of a Molecularly Imprinted Polymer for Dioxin

    OpenAIRE

    Magda Brattoli; Vito Sgobba; Giuseppe Ciccarella; Rosaria Anna Picca; Cosimino Malitesta

    2006-01-01

    A molecularly imprinted polymer for recognising selectively 2,3,7,8-tetrachlorodibenzodioxin (TCDD) was made by a new non-covalent method employing a“dummy†template. The proposed way represents a simplification of a synthetic schemeproposed by Lübke et al.[1] for covalent imprinting. Comparison of extraction yields of thenovel polymer, a non imprinted polymer and an imprinting polymer, prepared by theoriginal procedure demonstrates the binding capacity of the proposed polymer, wh...

  8. Molecularly imprinted polymers for alpha-tocopherol delivery.

    Science.gov (United States)

    Puoci, Francesco; Cirillo, Giuseppe; Curcio, Manuela; Iemma, Francesca; Parisi, Ortensia Ilaria; Castiglione, Mariarosaria; Picci, Nevio

    2008-05-01

    Biomedical applications of antioxidants have increased dramatically since the link between human diseases and oxidative stress was established. This paper focuses on alpha -tocopherol and on the possibility of employing molecularly imprinted polymers as a controlled release device for alpha-tocopherol in gastrointestinal simulating fluids. Polymers were synthesized using methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker. Considerable differences in recognition characteristics between imprinted and non-imprinted polymers, both in organic and in aqueous media, were observed. Imprinted polymers bound much more alpha-tocopherol and showed a controlled/sustained drug release capacity in gastrointestinal simulating fluids.

  9. [Biological decontamination of the imprints obtained from different dental materials].

    Science.gov (United States)

    Brekhlichuk, P P; Petrov, V O; Bati, V V; Levchuk, O B; Boĭko, N V

    2013-01-01

    Microbiological contamination of the imprints made of alginate ("Ypeen") and silicone material ("Speedex") with and without the correction supplement has been investigated. Streptococcus and Staphylococcus have been estimated to be the most survivable species on the imprint surface, however their concentration differ depending on the type of imprints' material. The strains resistant to antibiotics dominated among all the isolated microorganisms. Bacterial preparations based on Bacillus - Biosporin and Subalin and some extracts of edible plants, fruits and berries can be used in dentistry for the decontamination of imprints obtained by the use of different materials.

  10. Synthesis of a Molecularly Imprinted Polymer for Dioxin

    Directory of Open Access Journals (Sweden)

    Magda Brattoli

    2006-08-01

    Full Text Available A molecularly imprinted polymer for recognising selectively 2,3,7,8-tetrachlorodibenzodioxin (TCDD was made by a new non-covalent method employing a“dummy” template. The proposed way represents a simplification of a synthetic schemeproposed by Lübke et al.[1] for covalent imprinting. Comparison of extraction yields of thenovel polymer, a non imprinted polymer and an imprinting polymer, prepared by theoriginal procedure demonstrates the binding capacity of the proposed polymer, which is inprinciple applicable to solid phase extraction (SPE of dioxin.

  11. Phospholipid imprinted polymers as selective endotoxin scavengers

    Science.gov (United States)

    Sulc, Robert; Szekely, Gyorgy; Shinde, Sudhirkumar; Wierzbicka, Celina; Vilela, Filipe; Bauer, David; Sellergren, Börje

    2017-03-01

    Herein we explore phospholipid imprinting as a means to design receptors for complex glycolipids comprising the toxic lipopolysaccharide endotoxin. A series of polymerizable bis-imidazolium and urea hosts were evaluated as cationic and neutral hosts for phosphates and phosphonates, the latter used as mimics of the phospholipid head groups. The bis-imidazolium hosts interacted with the guests in a cooperative manner leading to the presence of tight and well defined 1:2 ternary complexes. Optimized monomer combinations were subsequently used for imprinting of phosphatidic acid as an endotoxin dummy template. Presence of the aforementioned ternary complexes during polymerization resulted in imprinting of lipid dimers - the latter believed to crudely mimic the endotoxin Lipid A motif. The polymers were characterized with respect to template rebinding, binding affinity, capacity and common structural properties, leading to the identification of polymers which were thereafter subjected to an industrially validated endotoxin removal test. Two of the polymers were capable of removing endotoxin down to levels well below the accepted threshold (0.005 EU/mg API) in pharmaceutical production.

  12. Phospholipid imprinted polymers as selective endotoxin scavengers

    Science.gov (United States)

    Sulc, Robert; Szekely, Gyorgy; Shinde, Sudhirkumar; Wierzbicka, Celina; Vilela, Filipe; Bauer, David; Sellergren, Börje

    2017-01-01

    Herein we explore phospholipid imprinting as a means to design receptors for complex glycolipids comprising the toxic lipopolysaccharide endotoxin. A series of polymerizable bis-imidazolium and urea hosts were evaluated as cationic and neutral hosts for phosphates and phosphonates, the latter used as mimics of the phospholipid head groups. The bis-imidazolium hosts interacted with the guests in a cooperative manner leading to the presence of tight and well defined 1:2 ternary complexes. Optimized monomer combinations were subsequently used for imprinting of phosphatidic acid as an endotoxin dummy template. Presence of the aforementioned ternary complexes during polymerization resulted in imprinting of lipid dimers – the latter believed to crudely mimic the endotoxin Lipid A motif. The polymers were characterized with respect to template rebinding, binding affinity, capacity and common structural properties, leading to the identification of polymers which were thereafter subjected to an industrially validated endotoxin removal test. Two of the polymers were capable of removing endotoxin down to levels well below the accepted threshold (0.005 EU/mg API) in pharmaceutical production. PMID:28303896

  13. Identification of the imprinted KLF14 transcription factor undergoing human-specific accelerated evolution.

    Science.gov (United States)

    Parker-Katiraee, Layla; Carson, Andrew R; Yamada, Takahiro; Arnaud, Philippe; Feil, Robert; Abu-Amero, Sayeda N; Moore, Gudrun E; Kaneda, Masahiro; Perry, George H; Stone, Anne C; Lee, Charles; Meguro-Horike, Makiko; Sasaki, Hiroyuki; Kobayashi, Keiko; Nakabayashi, Kazuhiko; Scherer, Stephen W

    2007-05-04

    Imprinted genes are expressed in a parent-of-origin manner and are located in clusters throughout the genome. Aberrations in the expression of imprinted genes on human Chromosome 7 have been suggested to play a role in the etiologies of Russell-Silver Syndrome and autism. We describe the imprinting of KLF14, an intronless member of the Krüppel-like family of transcription factors located at Chromosome 7q32. We show that it has monoallelic maternal expression in all embryonic and extra-embryonic tissues studied, in both human and mouse. We examine epigenetic modifications in the KLF14 CpG island in both species and find this region to be hypomethylated. In addition, we perform chromatin immunoprecipitation and find that the murine Klf14 CpG island lacks allele-specific histone modifications. Despite the absence of these defining features, our analysis of Klf14 in offspring from DNA methyltransferase 3a conditional knockout mice reveals that the gene's expression is dependent upon a maternally methylated region. Due to the intronless nature of Klf14 and its homology to Klf16, we suggest that the gene is an ancient retrotransposed copy of Klf16. By sequence analysis of numerous species, we place the timing of this event after the divergence of Marsupialia, yet prior to the divergence of the Xenarthra superclade. We identify a large number of sequence variants in KLF14 and, using several measures of diversity, we determine that there is greater variability in the human lineage with a significantly increased number of nonsynonymous changes, suggesting human-specific accelerated evolution. Thus, KLF14 may be the first example of an imprinted transcript undergoing accelerated evolution in the human lineage.

  14. Identification of the imprinted KLF14 transcription factor undergoing human-specific accelerated evolution.

    Directory of Open Access Journals (Sweden)

    Layla Parker-Katiraee

    2007-05-01

    Full Text Available Imprinted genes are expressed in a parent-of-origin manner and are located in clusters throughout the genome. Aberrations in the expression of imprinted genes on human Chromosome 7 have been suggested to play a role in the etiologies of Russell-Silver Syndrome and autism. We describe the imprinting of KLF14, an intronless member of the Krüppel-like family of transcription factors located at Chromosome 7q32. We show that it has monoallelic maternal expression in all embryonic and extra-embryonic tissues studied, in both human and mouse. We examine epigenetic modifications in the KLF14 CpG island in both species and find this region to be hypomethylated. In addition, we perform chromatin immunoprecipitation and find that the murine Klf14 CpG island lacks allele-specific histone modifications. Despite the absence of these defining features, our analysis of Klf14 in offspring from DNA methyltransferase 3a conditional knockout mice reveals that the gene's expression is dependent upon a maternally methylated region. Due to the intronless nature of Klf14 and its homology to Klf16, we suggest that the gene is an ancient retrotransposed copy of Klf16. By sequence analysis of numerous species, we place the timing of this event after the divergence of Marsupialia, yet prior to the divergence of the Xenarthra superclade. We identify a large number of sequence variants in KLF14 and, using several measures of diversity, we determine that there is greater variability in the human lineage with a significantly increased number of nonsynonymous changes, suggesting human-specific accelerated evolution. Thus, KLF14 may be the first example of an imprinted transcript undergoing accelerated evolution in the human lineage.

  15. Preparation of protein imprinted materials by hierarchical imprinting techniques and application in selective depletion of albumin from human serum

    Science.gov (United States)

    Liu, Jinxiang; Deng, Qiliang; Tao, Dingyin; Yang, Kaiguang; Zhang, Lihua; Liang, Zhen; Zhang, Yukui

    2014-06-01

    Hierarchical imprinting was developed to prepare the protein imprinted materials, as the artificial antibody, for the selective depletion of HSA from the human serum proteome. Porcine serum albumin (PSA) was employed as the dummy template for the fabrication of the recognition sites. To demonstrate the advantages of the hierarchical imprinting, molecularly imprinted polymers prepared by hierarchical imprinting technique (h-MIPs) were compared with those obtained by bulk imprinting (b-MIPs), in terms of the binding capacity, adsorption kinetics, selectivity and synthesis reproducibility. The binding capacity of h-MIPs could reach 12 mg g-1. And saturation binding could be reached in less than 20 min for the h-MIPs. In the protein mixture, h-MIPs exhibit excellent selectivity for PSA, with imprinting factors as about 3.6, much higher than those for non-template proteins. For the proteomic application, the identified protein group number in serum treated by h-MIPs was increased to 422, which is 21% higher than that obtained from the original serum, meanwhile the identified protein group number for the Albumin Removal kit was only 376. The results demonstrate that protein imprinted polymers prepared by hierarchical imprinting technique, might become the artificial antibodies for the selective depletion of high abundance proteins in proteome study.

  16. Role of imprint/exfoliative cytology in ulcerated skin neoplasms.

    Science.gov (United States)

    Ramakrishnaiah, Vishnu Prasad Nelamangala; Babu, Ravindra; Pai, Dinker; Verma, Surendra Kumar

    2013-12-01

    Imprint cytology is a method of studying cells by taking an imprint from the cut surface of a wedge biopsy specimen or from the resected margins of a surgical specimen. It is rapid, simple and fairly accurate. Exfoliative cytology is an offshoot from the imprint cytology where in cells obtained from the surface of ulcers, either by scrape or brush, are analyzed for the presence of malignant cells. We undertook this study to see the role of imprint/exfoliative cytology in the diagnosis of ulcerated skin neoplasm and to check the adequacy of resected margins intra-operatively. This was a prospective investigative study conducted from September 2003 to July 2005. All patients presenting to surgical clinic with ulcerated skin and soft tissue tumours were included in the study. A wedge biopsy obtained from the ulcer and imprint smears were taken from the cut surface. Exfoliative cytology was analyzed from the surface smears. Wedge biopsy specimen was sent for histopathological (HPE) examination. The cytology and HPE were analyzed by a separate pathologist. Imprint cytology was also used to check the adequacy of resected margins in case of wide excision. This was compared with final HPE. Total of 107 patients was included in the present study and 474 imprint smears were done, with an average of 4.43 slides per lesion. Out of 59 wide excision samples, 132 imprint smears were prepared for assessing resected margins accounting for an average of 2.24 slides per each excised lesion. On combining imprint cytology with exfoliative cytology the overall sensitivity, specificity and positive predictive value were 90.38 %, 100 % and 90.38 % respectively. Only one out of 59 cases had a positive resected margin which was not picked by imprint cytology. Imprint cytology can be used for rapid and accurate diagnosis of various skin malignancies. It can also be used to check the adequacy of the resected margin intraoperatively.

  17. Targeted deletion of the Nesp55 DMR defines another Gnas imprinting control region and provides a mouse model of autosomal dominant PHP-Ib.

    Science.gov (United States)

    Fröhlich, Leopold F; Mrakovcic, Maria; Steinborn, Ralf; Chung, Ung-Il; Bastepe, Murat; Jüppner, Harald

    2010-05-18

    Approximately 100 genes undergo genomic imprinting. Mutations in fewer than 10 imprinted genetic loci, including GNAS, are associated with complex human diseases that differ phenotypically based on the parent transmitting the mutation. Besides the ubiquitously expressed Gsalpha, which is of broad biological importance, GNAS gives rise to an antisense transcript and to several Gsalpha variants that are transcribed from the nonmethylated parental allele. We previously identified two almost identical GNAS microdeletions extending from exon NESP55 to antisense (AS) exon 3 (delNESP55/delAS3-4). When inherited maternally, both deletions are associated with erasure of all maternal GNAS methylation imprints and autosomal-dominant pseudohypoparathyroidism type Ib, a disorder characterized by parathyroid hormone-resistant hypocalcemia and hyperphosphatemia. As for other imprinting disorders, the mechanisms resulting in abnormal GNAS methylation are largely unknown, in part because of a paucity of suitable animal models. We now showed in mice that deletion of the region equivalent to delNESP55/delAS3-4 on the paternal allele (DeltaNesp55(p)) leads to healthy animals without Gnas methylation changes. In contrast, mice carrying the deletion on the maternal allele (DeltaNesp55(m)) showed loss of all maternal Gnas methylation imprints, leading in kidney to increased 1A transcription and decreased Gsalpha mRNA levels, and to associated hypocalcemia, hyperphosphatemia, and secondary hyperparathyroidism. Besides representing a murine autosomal-dominant pseudohypoparathyroidism type Ib model and one of only few animal models for imprinted human disorders, our findings suggest that the Nesp55 differentially methylated region is an additional principal imprinting control region, which directs Gnas methylation and thereby affects expression of all maternal Gnas-derived transcripts.

  18. Investigation of imprinting parameters and their recognition nature for quinine-molecularly imprinted polymers

    Science.gov (United States)

    He, Jian-feng; Zhu, Quan-hong; Deng, Qin-ying

    2007-08-01

    A series of molecularly imprinted polymers (MIPs) was prepared using quinine as the template molecules by bulk polymerization. The presence of monomer-template solution complexes in non-covalent MIPs systems has been verified by both fluorescence and UV-vis spectrometric detection. The influence of different synthetic conditions (porogen, functional monomer, cross-linkers, initiation methods, monomer-template ratio, etc.) on recognition properties of the polymers was investigated. Scatchard analysis revealed that two classes of binding sites were formed in the imprinted polymer. The corresponding dissociation constants were estimated to be 45.00 μmol l -1 and 1.42 mmol l -1, respectively, by utilizing a multi-site recognition model. The binding characteristics of the imprinted polymers were explored in various solvents using equilibrium binding experiments. In the organic media, results suggested that polar interactions (hydrogen bonding, ionic interactions, etc.) between acidic monomer/polymer and template molecules were mainly responsible for the recognition, whereas in aqueous media, hydrophobic interactions had a remarkable non-specific contribution to the overall binding. The specificity of MIP was evaluated by rebinding the other structurally similar compounds. The results indicated that the imprinted polymers exhibited an excellent stereo-selectivity toward quinine.

  19. Imprinting diseases and IVF: Danish National IVF cohort study

    DEFF Research Database (Denmark)

    Lidegaard, Ojvind; Pinborg, Anja; Andersen, Anders Nyboe

    2005-01-01

    The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children.......The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children....

  20. Imprinting can cause a maladaptive preference for infectious conspecifics.

    Science.gov (United States)

    Stephenson, Jessica F; Reynolds, Michael

    2016-04-01

    Recognizing and associating with specific individuals, such as conspecifics or kin, brings many benefits. One mechanism underlying such recognition is imprinting: the long-term memory of cues encountered during development. Typically, juveniles imprint on cues of nearby individuals and may later associate with phenotypes matching their 'recognition template'. However, phenotype matching could lead to maladaptive social decisions if, for instance, individuals imprint on the cues of conspecifics infected with directly transmitted diseases. To investigate the role of imprinting in the sensory ecology of disease transmission, we exposed juvenile guppies,Poecilia reticulata, to the cues of healthy conspecifics, or to those experiencing disease caused by the directly transmitted parasite Gyrodactylus turnbulli In a dichotomous choice test, adult 'disease-imprinted' guppies preferred to associate with the chemical cues of G. turnbulli-infected conspecifics, whereas 'healthy-imprinted' guppies preferred to associate with cues of uninfected conspecifics. These responses were only observed when stimulus fish were in late infection, suggesting imprinted fish responded to cues of disease, but not of infection alone. We discuss how maladaptive imprinting may promote disease transmission in natural populations of a social host. © 2016 The Author(s).

  1. A STUDY OF BLOCKING AND OVERSHADOWING IN FILIAL IMPRINTING

    NARCIS (Netherlands)

    VANKAMPEN, HS; DEVOS, GJ

    1995-01-01

    The occurrence of blocking and overshadowing in filial imprinting was investigated in junglefowl chicks (Gallus gallus spadiceus). When subjects were exposed to a novel object in the presence of a familiar one, imprinting on the novel object was impaired in one of two experimental groups (Experiment

  2. A STUDY OF BLOCKING AND OVERSHADOWING IN FILIAL IMPRINTING

    NARCIS (Netherlands)

    VANKAMPEN, HS; DEVOS, GJ

    1995-01-01

    The occurrence of blocking and overshadowing in filial imprinting was investigated in junglefowl chicks (Gallus gallus spadiceus). When subjects were exposed to a novel object in the presence of a familiar one, imprinting on the novel object was impaired in one of two experimental groups (Experiment

  3. Molecularly imprinted nanotubes for enantioselective drug delivery and controlled release.

    Science.gov (United States)

    Yin, Junfa; Cui, Yue; Yang, Gengliang; Wang, Hailin

    2010-11-07

    Molecularly imprinted nanotubes for enantioselective drug delivery and controlled release are fabricated by the combination of template synthesis and ATRP grafting. The release of R-propranolol from the imprinted nanotubes in rats is restricted while the release of pharmacologically active S-enantiomer is greatly promoted.

  4. DNA replication: stalling a fork for imprinting and switching

    DEFF Research Database (Denmark)

    Egel, Richard

    2004-01-01

    Mating-type switching in fission yeast has long been known to be directed by a DNA 'imprint'. This imprint has now been firmly characterized as a protected site-specific and strand-specific nick. New work also links the widely conserved Swi1-Swi3 complex to the protection of stalled replication...

  5. Development of fructosyl valine binding polymers by covalent imprinting.

    Science.gov (United States)

    Rajkumar, Rajagopal; Warsinke, Axel; Möhwald, Helmuth; Scheller, Frieder W; Katterle, Martin

    2007-06-15

    Molecularly imprinted polymers (MIPs) against fructosyl valine (Fru-Val), the N-terminal constituent of hemoglobin A1c beta-chains, were prepared by cross-linking of beta-D-Fru-Val-O-bis(4-vinylphenylboronate) with an excess of ethylene glycol dimethacrylate (EDMA) or trimethylolpropane trimethacrylate (TRIM). Control MIPs were prepared in analogy by cross-linking the corresponding vinylphenylboronate esters of fructose and pinacol. After template extraction batch rebinding studies were performed using different pH values and buffer compositions. The Fru-Val imprinted TRIM cross-linked polymer binds about 1.4 times more Fru-Val than the fructose imprinted polymer and 2.7 times more Fru-Val than pinacol imprinted polymer. The highest imprinting effect was obtained in 100 mM sodium carbonate/10% methanol (pH 11.4). The TRIM cross-linked Fru-Val imprinted polymer showed a better specificity than the EDMA cross-linked polymer. The binding of valine was very low. Thermo gravimetric analysis indicated that the generated Fru-Val imprinted polymer has high thermo stability. No change in binding was observed after incubation of the polymers in buffer at 80 degrees C for 36 h. Since the functional group of the polymers (phenyl boronic acid) targets the sugar part of Fru-Val the imprint technique used should also be applicable for the development of MIPs against other glycated amino acids and peptides.

  6. Imprinting diseases and IVF: Danish National IVF cohort study

    DEFF Research Database (Denmark)

    Lidegaard, Ojvind; Pinborg, Anja; Andersen, Anders Nyboe

    2005-01-01

    The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children.......The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children....

  7. Mycotoxin analysis using imprinted materials technology: Recent developments

    Science.gov (United States)

    Molecular imprinting technology is an attractive, cost effective, and robust alternative to address the limitations of highly selective natural receptors, such as antibodies and aptamers. The field of molecular imprinting has seen a recent surge in growth with several commercially available products...

  8. Characteristic and Synthetic Approach of Molecularly Imprinted Polymer

    Directory of Open Access Journals (Sweden)

    Kyung Ho Row

    2006-06-01

    Full Text Available Molecularly imprinted polymers (MIP exhibiting high selectivity and affinity tothe predetermined molecule (template are now seeing a fast growing research. However,optimization of the imprinted products is difficult due to the fact that there are manyvariables to consider, some or all of which can potentially impact upon the chemical,morphological and molecular recognition properties of the imprinted materials. This reviewpresent a summary of the principal synthetic considerations pertaining to good practice in thepolymerization aspects of molecular imprinting, and is primarily aimed at researcher familiarwith molecular imprinting methods but with little or no prior experience in polymersynthesis. The synthesis, characteristic, effect of molecular recognition and differentpreparation methods of MIP in recent few years are discussed in this review, unsolvedproblems and possible developments of MIP were also been briefly discussed.

  9. Molecularly imprinted macroporous monolithic materials for protein recognition

    Institute of Scientific and Technical Information of China (English)

    Qi Liang Deng; Yan Li Li; Li Hua Zhang; Yu Kui Zhang

    2011-01-01

    Synthetic materials that can specifically recognize proteins will find wide application in many fields. In this report, bovine serum albumin was chosen as the template protein. Acrylamide and N, N'-methylenebisacrylamide were employed as the functional and cross-linker monomers, respectively. Molecularly imprinted macroporous monolithic materials that can preferentially bind the template protein in an aqueous environment were prepared by combination of molecular imprinting technique and freezing/thawing preparation method. The resulted imprinted macroporous monolithic columns were evaluated by utilizing as stationary phase in high performance liquid chromatography and solid-phase extraction materials. The experimental results indicated that the imprinted macroporous monolithic column exhibited good recognition for template protein, as compared with the control protein (hemoglobin), whereas the non-imprinted polymer (prepared under the same conditions except without addition template protein) had no selective properties.

  10. Small organic molecular imprinted materials: their preparation and application.

    Science.gov (United States)

    Jiang, Xiaoman; Jiang, Na; Zhang, Haixia; Liu, Mancang

    2007-09-01

    Molecular imprinting is a technique for preparing polymeric materials that are capable of recognizing and binding the desired molecular target with a high affinity and selectivity. The materials can be applied to a wide range of target molecules, even those for which no natural binder exists or whose antibodies are difficult to raise. The imprinting of small organic molecules (e.g., pharmaceuticals, pesticides, amino acids, steroids, and sugars) is now almost routine. In this review, we pay special attention to the synthesis and application of molecular imprinted polymer (MIPs) imprinted with small organic molecules, including herbicides, pesticides, and drugs. The advantages, applications, and recent developments in small organic molecular imprinted technology are highlighted.

  11. A novel pathway links oxidative stress to loss of insulin growth factor-2 (IGF2 imprinting through NF-κB activation.

    Directory of Open Access Journals (Sweden)

    Bing Yang

    Full Text Available Genomic imprinting is the allele-specific expression of a gene based on parental origin. Loss of imprinting(LOI of Insulin-like Growth Factor 2 (IGF2 during aging is important in tumorigenesis, yet the regulatory mechanisms driving this event are largely unknown. In this study oxidative stress, measured by increased NF-κB activity, induces LOI in both cancerous and noncancerous human prostate cells. Decreased expression of the enhancer-blocking element CCCTC-binding factor(CTCF results in reduced binding of CTCF to the H19-ICR (imprint control region, a major factor in the allelic silencing of IGF2. This ICR then develops increased DNA methylation. Assays identify a recruitment of the canonical pathway proteins NF-κB p65 and p50 to the CTCF promoter associated with the co-repressor HDAC1 explaining gene repression. An IκBα super-repressor blocks oxidative stress-induced activation of NF-κB and IGF2 imprinting is maintained. In vivo experiments using IκBα mutant mice with continuous NF-κB activation demonstrate increased IGF2 LOI further confirming a central role for canonical NF-κB signaling. We conclude CTCF plays a central role in mediating the effects of NF-κB activation that result in altered imprinting both in vitro and in vivo. This novel finding connects inflammation found in aging prostate tissues with the altered epigenetic landscape.

  12. Glycogen synthase kinase-3 (Gsk-3) plays a fundamental role in maintaining DNA methylation at imprinted loci in mouse embryonic stem cells.

    Science.gov (United States)

    Meredith, Gavin D; D'Ippolito, Anthony; Dudas, Miroslav; Zeidner, Leigh C; Hostetter, Logan; Faulds, Kelsie; Arnold, Thomas H; Popkie, Anthony P; Doble, Bradley W; Marnellos, George; Adams, Christopher; Wang, Yulei; Phiel, Christopher J

    2015-06-01

    Glycogen synthase kinase-3 (Gsk-3) is a key regulator of multiple signal transduction pathways. Recently we described a novel role for Gsk-3 in the regulation of DNA methylation at imprinted loci in mouse embryonic stem cells (ESCs), suggesting that epigenetic changes regulated by Gsk-3 are likely an unrecognized facet of Gsk-3 signaling. Here we extend our initial observation to the entire mouse genome by enriching for methylated DNA with the MethylMiner kit and performing next-generation sequencing (MBD-Seq) in wild-type and Gsk-3α(-/-);Gsk-3β(-/-) ESCs. Consistent with our previous data, we found that 77% of known imprinted loci have reduced DNA methylation in Gsk-3-deficient ESCs. More specifically, we unambiguously identified changes in DNA methylation within regions that have been confirmed to function as imprinting control regions. In many cases, the reduced DNA methylation at imprinted loci in Gsk-3α(-/-);Gsk-3β(-/-) ESCs was accompanied by changes in gene expression as well. Furthermore, many of the Gsk-3-dependent, differentially methylated regions (DMRs) are identical to the DMRs recently identified in uniparental ESCs. Our data demonstrate the importance of Gsk-3 activity in the maintenance of DNA methylation at a majority of the imprinted loci in ESCs and emphasize the importance of Gsk-3-mediated signal transduction in the epigenome.

  13. The imprinted SNRPN gene is associated with a polycistronic mRNA and an imprinting control element

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, S.; Nicholls, R.D. [Case Western Reserve Univ., Cleveland, OH (United States); Seip, J. [Pennsylvania State Univ., Hershey, PA (United States)] [and others

    1994-09-01

    The small nuclear ribonucleoprotein-associated protein SmN (SNRPN) gene is located in the Prader-Willi syndrome (PWS) critical region in chromosome 15q11-q13. We have previously shown that it is functionally imprinted in humans, being only expressed from the paternal allele and differentially methylated on parental alleles. Therefore, SNRPN may have a role in PWS, although genetic studies suggest that at least two genes may be necessary for the classical PWS phenotype. We have characterized the SNRPN genomic structure, and shown that it comprises ten exons. Surprisingly, we identified an open reading frame (ORF) in the first three exons, 190-bp 5{prime} to the SmN ORF. Notably, the majority of base substitutions bewteen human and rodents in the upstream ORF occurred in the wobble position of codons, suggesting selection for a protein coding function. This ORF, which we name SNURF (SNRPN upstream reading frame) encodes a putative polypeptide of 71 amino acids. By analogy to prokaryotic operons that encode proteins with related functions, it is possible that SNURF may have a role in pre-mRNA splicing.

  14. Imprinting of Microorganisms for Biosensor Applications

    Science.gov (United States)

    Idil, Neslihan; Mattiasson, Bo

    2017-01-01

    There is a growing need for selective recognition of microorganisms in complex samples due to the rapidly emerging importance of detecting them in various matrices. Most of the conventional methods used to identify microorganisms are time-consuming, laborious and expensive. In recent years, many efforts have been put forth to develop alternative methods for the detection of microorganisms. These methods include use of various components such as silica nanoparticles, microfluidics, liquid crystals, carbon nanotubes which could be integrated with sensor technology in order to detect microorganisms. In many of these publications antibodies were used as recognition elements by means of specific interactions between the target cell and the binding site of the antibody for the purpose of cell recognition and detection. Even though natural antibodies have high selectivity and sensitivity, they have limited stability and tend to denature in conditions outside the physiological range. Among different approaches, biomimetic materials having superior properties have been used in creating artificial systems. Molecular imprinting is a well suited technique serving the purpose to develop highly selective sensing devices. Molecularly imprinted polymers defined as artificial recognition elements are of growing interest for applications in several sectors of life science involving the investigations on detecting molecules of specific interest. These polymers have attractive properties such as high bio-recognition capability, mechanical and chemical stability, easy preparation and low cost which make them superior over natural recognition reagents. This review summarizes the recent advances in the detection and quantification of microorganisms by emphasizing the molecular imprinting technology and its applications in the development of sensor strategies. PMID:28353629

  15. Imprint of Galactic dynamics on Earth's climate

    DEFF Research Database (Denmark)

    Svensmark, Henrik

    2006-01-01

    A connection between climate and the Solar system's motion perpendicular to the Galactic plane during the last 200 Myr years is studied. An imprint of galactic dynamics is found in a long-term record of the Earth's climate that is consistent with variations in the Solar system oscillation around ......(arm)/rho(interarm) approximate to 1.5-1.8), and finally, using current knowledge of spiral arm positions, a pattern speed of Omega(P) = 13.6 +/- 1.4 km s(-1) kpc(-1) is determined....

  16. Imprints of Anisotropic Inflation on the CMB

    CERN Document Server

    Watanabe, Masa-aki; Soda, Jiro

    2010-01-01

    We study the imprints of anisotropic inflation on the CMB temperature fluctuations and polarizations. The statistical anisotropy stems not only from the direction dependence of curvature and tensor perturbations, but also from the cross correlation between curvature and tensor perturbations, and the linear polarization of tensor perturbations. We show that off-diagonal $TB$ and $EB$ spectrum as well as on- and off-diagonal $TT, EE, BB, TE$ spectrum are induced from anisotropic inflation. We emphasize that the off-diagonal spectrum induced by the cross correlation could be a characteristic signature of anisotropic inflation.

  17. Oct4/Sox2 binding sites contribute to maintaining hypomethylation of the maternal igf2/h19 imprinting control region.

    Directory of Open Access Journals (Sweden)

    David L Zimmerman

    Full Text Available A central question in genomic imprinting is how parental-specific DNA methylation of imprinting control regions (ICR is established during gametogenesis and maintained after fertilization. At the imprinted Igf2/H19 locus, CTCF binding maintains the unmethylated state of the maternal ICR after the blastocyst stage. In addition, evidence from Beckwith-Wiedemann patients and cultured mouse cells suggests that two Sox-Oct binding motifs within the Igf2/H19 ICR also participate in maintaining hypomethylation of the maternal allele. We found that the Sox and octamer elements from both Sox-Oct motifs were required to drive hypomethylation of integrated transgenes in mouse embryonic carcinoma cells. Oct4 and Sox2 showed cooperative binding to the Sox-Oct motifs, and both were present at the endogenous ICR. Using a mouse with mutations in the Oct4 binding sites, we found that maternally transmitted mutant ICRs acquired partial methylation in somatic tissues, but there was little effect on imprinted expression of H19 and Igf2. A subset of mature oocytes also showed partial methylation of the mutant ICR, which suggested that the Sox-Oct motifs provide some protection from methylation during oogenesis. The Sox-Oct motifs, however, were not required for erasure of paternal methylation in primordial germ cells, which indicated that the oocyte methylation was acquired post-natally. Maternally inherited mutant ICRs were unmethylated in blastocysts, which suggested that at least a portion of the methylation in somatic tissues occurred after implantation. These findings provide evidence that Sox-Oct motifs contribute to ICR hypomethylation in post-implantation embryos and maturing oocytes and link imprinted DNA methylation with key stem cell/germline transcription factors.

  18. Molecular mechanisms of memory in imprinting.

    Science.gov (United States)

    Solomonia, Revaz O; McCabe, Brian J

    2015-03-01

    Converging evidence implicates the intermediate and medial mesopallium (IMM) of the domestic chick forebrain in memory for a visual imprinting stimulus. During and after imprinting training, neuronal responsiveness in the IMM to the familiar stimulus exhibits a distinct temporal profile, suggesting several memory phases. We discuss the temporal progression of learning-related biochemical changes in the IMM, relative to the start of this electrophysiological profile. c-fos gene expression increases <15 min after training onset, followed by a learning-related increase in Fos expression, in neurons immunopositive for GABA, taurine and parvalbumin (not calbindin). Approximately simultaneously or shortly after, there are increases in phosphorylation level of glutamate (AMPA) receptor subunits and in releasable neurotransmitter pools of GABA and taurine. Later, the mean area of spine synapse post-synaptic densities, N-methyl-D-aspartate receptor number and phosphorylation level of further synaptic proteins are elevated. After ∼ 15 h, learning-related changes in amounts of several synaptic proteins are observed. The results indicate progression from transient/labile to trophic synaptic modification, culminating in stable recognition memory. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  19. Sexual imprinting in human mate choice.

    Science.gov (United States)

    Bereczkei, Tamas; Gyuris, Petra; Weisfeld, Glenn E

    2004-06-07

    Animal and human studies have shown that individuals choose mates partly on the basis of similarity, a tendency referred to as homogamy. Several authors have suggested that a specific innate recognition mechanism, phenotypic matching, allows the organism to detect similar others by their resemblance to itself. However, several objections have been raised to this theory on both empirical and theoretical grounds. Here, we report that homogamy in humans is attained partly by sexual imprinting on the opposite-sex parent during childhood. We hypothesized that children fashion a mental model of their opposite-sex parent's phenotype that is used as a template for acquiring mates. To disentangle the effects of phenotypic matching and sexual imprinting, adopted daughters and their rearing families were examined. Judges found significant resemblance on facial traits between daughter's husband and her adoptive father. Furthermore, this effect may be modified by the quality of the father-daughter relationship during childhood. Daughters who received more emotional support from their adoptive father were more likely to choose mates similar to the father than those whose father provided a less positive emotional atmosphere.

  20. Molecular mechanisms of memory in imprinting

    Science.gov (United States)

    Solomonia, Revaz O.; McCabe, Brian J.

    2015-01-01

    Converging evidence implicates the intermediate and medial mesopallium (IMM) of the domestic chick forebrain in memory for a visual imprinting stimulus. During and after imprinting training, neuronal responsiveness in the IMM to the familiar stimulus exhibits a distinct temporal profile, suggesting several memory phases. We discuss the temporal progression of learning-related biochemical changes in the IMM, relative to the start of this electrophysiological profile. c-fos gene expression increases <15 min after training onset, followed by a learning-related increase in Fos expression, in neurons immunopositive for GABA, taurine and parvalbumin (not calbindin). Approximately simultaneously or shortly after, there are increases in phosphorylation level of glutamate (AMPA) receptor subunits and in releasable neurotransmitter pools of GABA and taurine. Later, the mean area of spine synapse post-synaptic densities, N-methyl-d-aspartate receptor number and phosphorylation level of further synaptic proteins are elevated. After ∼15 h, learning-related changes in amounts of several synaptic proteins are observed. The results indicate progression from transient/labile to trophic synaptic modification, culminating in stable recognition memory. PMID:25280906

  1. Molecularly Imprinted Filtering Adsorbents for Odor Sensing

    Directory of Open Access Journals (Sweden)

    Sho Shinohara

    2016-11-01

    Full Text Available Versatile odor sensors that can discriminate among huge numbers of environmental odorants are desired in many fields, including robotics, environmental monitoring, and food production. However, odor sensors comparable to an animal’s nose have not yet been developed. An animal’s olfactory system recognizes odor clusters with specific molecular properties and uses this combinatorial information in odor discrimination. This suggests that measurement and clustering of odor molecular properties (e.g., polarity, size using an artificial sensor is a promising approach to odor sensing. Here, adsorbents composed of composite materials with molecular recognition properties were developed for odor sensing. The selectivity of the sensor depends on the adsorbent materials, so specific polymeric materials with particular solubility parameters were chosen to adsorb odorants with various properties. The adsorption properties of the adsorbents could be modified by mixing adsorbent materials. Moreover, a novel molecularly imprinted filtering adsorbent (MIFA, composed of an adsorbent substrate covered with a molecularly imprinted polymer (MIP layer, was developed to improve the odor molecular recognition ability. The combination of the adsorbent and MIP layer provided a higher specificity toward target molecules. The MIFA thus provides a useful technique for the design and control of adsorbents with adsorption properties specific to particular odor molecules.

  2. Econazole imprinted textiles with antifungal activity.

    Science.gov (United States)

    Hossain, Mirza Akram; Lalloz, Augustine; Benhaddou, Aicha; Pagniez, Fabrice; Raymond, Martine; Le Pape, Patrice; Simard, Pierre; Théberge, Karine; Leblond, Jeanne

    2016-04-01

    In this work, we propose pharmaceutical textiles imprinted with lipid microparticles of Econazole nitrate (ECN) as a mean to improve patient compliance while maintaining drug activity. Lipid microparticles were prepared and characterized by laser diffraction (3.5±0.1 μm). Using an optimized screen-printing method, microparticles were deposited on textiles, as observed by scanning electron microscopy. The drug content of textiles (97±3 μg/cm(2)) was reproducible and stable up to 4 months storage at 25 °C/65% Relative Humidity. Imprinted textiles exhibited a thermosensitive behavior, as witnessed by a fusion temperature of 34.8 °C, which enabled a larger drug release at 32 °C (temperature of the skin) than at room temperature. In vitro antifungal activity of ECN textiles was compared to commercial 1% (wt/wt) ECN cream Pevaryl®. ECN textiles maintained their antifungal activity against a broad range of Candida species as well as major dermatophyte species. In vivo, ECN textiles also preserved the antifungal efficacy of ECN on cutaneous candidiasis infection in mice. Ex vivo percutaneous absorption studies demonstrated that ECN released from pharmaceutical textiles concentrated more in the upper skin layers, where the fungal infections develop, as compared to dermal absorption of Pevaryl®. Overall, these results showed that this technology is promising to develop pharmaceutical garments textiles for the treatment of superficial fungal infections.

  3. Genome scan for parent-of-origin QTL effects on bovine growth and carcass traits

    NARCIS (Netherlands)

    Imumorin, I.G.; Kim, B.; Li, Y.; Koning, de D.J.; Arendonk, van J.A.M.; Donato, S.

    2011-01-01

    Parent-of-origin effects (POE) such as genomic imprinting influence growth and body composition in livestock, rodents, and humans. Here, we report the results of a genome scan to detect quantitative trait loci (QTL) with POE on growth and carcass traits in Angus × Brahman cattle crossbreds. We

  4. Genome scan for parent-of-origin QTL effects on bovine growth and carcass traits

    NARCIS (Netherlands)

    Imumorin, I.G.; Kim, B.; Li, Y.; Koning, de D.J.; Arendonk, van J.A.M.; Donato, S.

    2011-01-01

    Parent-of-origin effects (POE) such as genomic imprinting influence growth and body composition in livestock, rodents, and humans. Here, we report the results of a genome scan to detect quantitative trait loci (QTL) with POE on growth and carcass traits in Angus × Brahman cattle crossbreds. We ident

  5. Involvement of nucleotide diphosphate kinase 2 in the reopening of the sensitive period of filial imprinting of domestic chicks (Gallus gallus domesticus).

    Science.gov (United States)

    Yamaguchi, Shinji; Aoki, Naoya; Takehara, Akihiko; Mori, Masaru; Kanai, Akio; Matsushima, Toshiya; Homma, Koichi J

    2016-01-26

    Filial imprinting is a behavior characterized by the sensitive or critical period restricted to the first few days after hatching. Once the sensitive period is closed, it is widely believed that chicks can never be imprinted under natural conditions. Previously, we showed that the exogenous injection of T3 reopened the sensitive period which was already closed. That study suggested that T3 functioned by way of a rapid non-genomic action; however, the molecular mechanism of how T3 reopens the sensitive period remains unknown. Here, we show that the phosphorylation level of nucleotide diphosphate kinase 2 (NDPK2) was upregulated following T3 injection. Pharmacological deprivation of the kinase activity of NDPK hampered the molecular process prerequisite for the reopening of the sensitive period of filial imprinting. Moreover, it is shown that the kinase activity of NDPK2 participates in the priming process by T3 signaling which endows the potential for learning. Our data indicate that NDPK2 plays a crucial role downstream of T3 action and that its phosphorylation is involved in the non-genomic signaling during imprinting. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. An RNA-Seq strategy to detect the complete coding and non-coding transcriptome including full-length imprinted macro ncRNAs.

    Directory of Open Access Journals (Sweden)

    Ru Huang

    Full Text Available Imprinted macro non-protein-coding (nc RNAs are cis-repressor transcripts that silence multiple genes in at least three imprinted gene clusters in the mouse genome. Similar macro or long ncRNAs are abundant in the mammalian genome. Here we present the full coding and non-coding transcriptome of two mouse tissues: differentiated ES cells and fetal head using an optimized RNA-Seq strategy. The data produced is highly reproducible in different sequencing locations and is able to detect the full length of imprinted macro ncRNAs such as Airn and Kcnq1ot1, whose length ranges between 80-118 kb. Transcripts show a more uniform read coverage when RNA is fragmented with RNA hydrolysis compared with cDNA fragmentation by shearing. Irrespective of the fragmentation method, all coding and non-coding transcripts longer than 8 kb show a gradual loss of sequencing tags towards the 3' end. Comparisons to published RNA-Seq datasets show that the strategy presented here is more efficient in detecting known functional imprinted macro ncRNAs and also indicate that standardization of RNA preparation protocols would increase the comparability of the transcriptome between different RNA-Seq datasets.

  7. The gene locus encoding iodothyronine deiodinase type 3 (Dio3) is imprinted in the fetus and expresses antisense transcripts.

    Science.gov (United States)

    Hernandez, Arturo; Fiering, Steven; Martinez, Elena; Galton, Valerie Anne; St Germain, Donald

    2002-11-01

    The mouse Dio3 gene codes for the type 3 iodothyronine deiodinase (D3), a conserved selenocysteine-containing enzyme that inactivates thyroid hormones and is highly expressed during early development. The mouse Dio3 gene and its human homolog map to chromosomal regions that are known to contain imprinted genes. We assessed the allelic expression of the Dio3 using a mouse model in which the gene had been inactivated by the introduction of a critical mutation in the selenocysteine codon. We compared Dio3 gene expression in fetuses that were either wild type or heterozygous (+/-Dio3) for the mutation. D3 enzymatic activities in the head, limbs, liver and body of heterozygous fetuses (E14 to E18) that inherited the mutation from the mother were no different from those found in their wild type littermates. However, D3 activities in heterozygous animals that inherited the mutation from the father were only 18 to 28% of the activities of their wild type littermates in these same tissues. No detectable activity was found in fetuses homozygous for the mutation indicating full inactivation of the enzyme. Northern analysis of mRNA from E15 fetuses showed that the Dio3 mRNA transcripts generated from the paternal allele were at least 5 times more abundant than the transcripts originated from the maternal allele. We conclude that the Dio3 gene is subject to genomic imprinting and preferentially expressed from the paternal allele in the mouse fetus. We also identified a gene that is transcribed antisense from the Dio3 locus. The Dio3 gene likely belongs to the same cluster of imprinted genes detected in mouse chromosome 12 and human chromosome 14 and should be considered as a candidate gene that might play a role in the phenotypic abnormalities associated with uniparental disomy of those chromosomes, a condition in which gene expression is altered due to abnormal genomic imprinting.

  8. Placental hydroxymethylation vs methylation at the imprinting control region 2 on chromosome 11p15.5

    Directory of Open Access Journals (Sweden)

    H.R. Magalhaes

    2013-11-01

    Full Text Available In addition to methylated cytosines (5-mCs, hydroxymethylcytosines (5-hmCs are present in CpG dinucleotide-enriched regions and some transcription regulator binding sites. Unlike methylation, hydroxymethylation does not result in silencing of gene expression, and the most commonly used methods to study methylation, such as techniques based on restriction enzymatic digestion and/or bisulfite modification, are unable to distinguish between them. Genomic imprinting is a process of gene regulation where only one member of an allelic pair is expressed depending on the parental origin. Chromosome 11p15.5 has an imprinting control region (ICR2 that includes a differentially methylated region (KvDMR1 that guarantees parent-specific gene expression. The objective of the present study was to determine the presence of 5-hmC at the KvDMR1 in human placentas. We analyzed 16 third-trimester normal human placentas (chorionic villi. We compared two different methods based on real-time PCR after enzymatic digestion. The first method distinguished methylation from hydroxymethylation, while the other method did not. Unlike other methylation studies, subtle variations of methylation in ICRs could represent a drastic deregulation of the expression of imprinted genes, leading to important phenotypic consequences, and the presence of hydroxymethylation could interfere with the results of many studies. We observed agreement between the results of both methods, indicating the absence of hydroxymethylation at the KvDMR1 in third-trimester placentas. To the best of our knowledge, this is the first study describing the investigation of hydroxymethylation in human placenta using a genomic imprinting model.

  9. Placental hydroxymethylation vs methylation at the imprinting control region 2 on chromosome 11p15.5.

    Science.gov (United States)

    Magalhães, H R; Leite, S B P; Paz, C C P de; Duarte, G; Ramos, E S

    2013-10-22

    In addition to methylated cytosines (5-mCs), hydroxymethylcytosines (5-hmCs) are present in CpG dinucleotide-enriched regions and some transcription regulator binding sites. Unlike methylation, hydroxymethylation does not result in silencing of gene expression, and the most commonly used methods to study methylation, such as techniques based on restriction enzymatic digestion and/or bisulfite modification, are unable to distinguish between them. Genomic imprinting is a process of gene regulation where only one member of an allelic pair is expressed depending on the parental origin. Chromosome 11p15.5 has an imprinting control region (ICR2) that includes a differentially methylated region (KvDMR1) that guarantees parent-specific gene expression. The objective of the present study was to determine the presence of 5-hmC at the KvDMR1 in human placentas. We analyzed 16 third-trimester normal human placentas (chorionic villi). We compared two different methods based on real-time PCR after enzymatic digestion. The first method distinguished methylation from hydroxymethylation, while the other method did not. Unlike other methylation studies, subtle variations of methylation in ICRs could represent a drastic deregulation of the expression of imprinted genes, leading to important phenotypic consequences, and the presence of hydroxymethylation could interfere with the results of many studies. We observed agreement between the results of both methods, indicating the absence of hydroxymethylation at the KvDMR1 in third-trimester placentas. To the best of our knowledge, this is the first study describing the investigation of hydroxymethylation in human placenta using a genomic imprinting model.

  10. Neuronal plasticity and multisensory integration in filial imprinting.

    Science.gov (United States)

    Town, Stephen Michael; McCabe, Brian John

    2011-03-10

    Many organisms sample their environment through multiple sensory systems and the integration of multisensory information enhances learning. However, the mechanisms underlying multisensory memory formation and their similarity to unisensory mechanisms remain unclear. Filial imprinting is one example in which experience is multisensory, and the mechanisms of unisensory neuronal plasticity are well established. We investigated the storage of audiovisual information through experience by comparing the activity of neurons in the intermediate and medial mesopallium of imprinted and naïve domestic chicks (Gallus gallus domesticus) in response to an audiovisual imprinting stimulus and novel object and their auditory and visual components. We find that imprinting enhanced the mean response magnitude of neurons to unisensory but not multisensory stimuli. Furthermore, imprinting enhanced responses to incongruent audiovisual stimuli comprised of mismatched auditory and visual components. Our results suggest that the effects of imprinting on the unisensory and multisensory responsiveness of IMM neurons differ and that IMM neurons may function to detect unexpected deviations from the audiovisual imprinting stimulus.

  11. A model for transgenerational imprinting variation in complex traits.

    Science.gov (United States)

    Wang, Chenguang; Wang, Zhong; Luo, Jiangtao; Li, Qin; Li, Yao; Ahn, Kwangmi; Prows, Daniel R; Wu, Rongling

    2010-07-14

    Despite the fact that genetic imprinting, i.e., differential expression of the same allele due to its different parental origins, plays a pivotal role in controlling complex traits or diseases, the origin, action and transmission mode of imprinted genes have still remained largely unexplored. We present a new strategy for studying these properties of genetic imprinting with a two-stage reciprocal F mating design, initiated with two contrasting inbred lines. This strategy maps quantitative trait loci that are imprinted (i.e., iQTLs) based on their segregation and transmission across different generations. By incorporating the allelic configuration of an iQTL genotype into a mixture model framework, this strategy provides a path to trace the parental origin of alleles from previous generations. The imprinting effects of iQTLs and their interactions with other traditionally defined genetic effects, expressed in different generations, are estimated and tested by implementing the EM algorithm. The strategy was used to map iQTLs responsible for survival time with four reciprocal F populations and test whether and how the detected iQTLs inherit their imprinting effects into the next generation. The new strategy will provide a tool for quantifying the role of imprinting effects in the creation and maintenance of phenotypic diversity and elucidating a comprehensive picture of the genetic architecture of complex traits and diseases.

  12. A model for transgenerational imprinting variation in complex traits.

    Directory of Open Access Journals (Sweden)

    Chenguang Wang

    Full Text Available Despite the fact that genetic imprinting, i.e., differential expression of the same allele due to its different parental origins, plays a pivotal role in controlling complex traits or diseases, the origin, action and transmission mode of imprinted genes have still remained largely unexplored. We present a new strategy for studying these properties of genetic imprinting with a two-stage reciprocal F mating design, initiated with two contrasting inbred lines. This strategy maps quantitative trait loci that are imprinted (i.e., iQTLs based on their segregation and transmission across different generations. By incorporating the allelic configuration of an iQTL genotype into a mixture model framework, this strategy provides a path to trace the parental origin of alleles from previous generations. The imprinting effects of iQTLs and their interactions with other traditionally defined genetic effects, expressed in different generations, are estimated and tested by implementing the EM algorithm. The strategy was used to map iQTLs responsible for survival time with four reciprocal F populations and test whether and how the detected iQTLs inherit their imprinting effects into the next generation. The new strategy will provide a tool for quantifying the role of imprinting effects in the creation and maintenance of phenotypic diversity and elucidating a comprehensive picture of the genetic architecture of complex traits and diseases.

  13. Characterization of the Binding Properties of Molecularly Imprinted Polymers.

    Science.gov (United States)

    Ansell, Richard J

    2015-01-01

    The defining characteristic of the binding sites of any particular molecularly imprinted material is heterogeneity: that is, they are not all identical. Nonetheless, it is useful to study their fundamental binding properties, and to obtain average properties. In particular, it has been instructive to compare the binding properties of imprinted and non-imprinted materials. This chapter begins by considering the origins of this site heterogeneity. Next, the properties of interest of imprinted binding sites are described in brief: affinity, selectivity, and kinetics. The binding/adsorption isotherm, the graph of concentration of analyte bound to a MIP versus concentration of free analyte at equilibrium, over a range of total concentrations, is described in some detail. Following this, the techniques for studying the imprinted sites are described (batch-binding assays, radioligand binding assays, zonal chromatography, frontal chromatography, calorimetry, and others). Thereafter, the parameters that influence affinity, selectivity and kinetics are discussed (solvent, modifiers of organic solvents, pH of aqueous solvents, temperature). Finally, mathematical attempts to fit the adsorption isotherms for imprinted materials, so as to obtain information about the range of binding affinities characterizing the imprinted sites, are summarized.

  14. THE DIAGNOSTIC ACCURACY OF IMPRINT CYTOLOGY IN BREAST LESIONS

    Directory of Open Access Journals (Sweden)

    Shashidhar

    2015-03-01

    Full Text Available BACKGROUND : The imprint cytology is one of the rapid diagnostic tools in the field of diagnostic pathology. This method not only helps us to examine the individual cells but also aids in analyzing the patterns of particular lesion. Differentiating between benign and malignant lesions prior to or during surgery, helps the surgeon to decide on the extent of surgery. AIMS : The present study was conducted to know the accuracy of intraoperative imprint smears and to compare the results with that of histopathological sections in all breast tumors. MATERIALS AND METHOD S : This was a descriptive study on 100 cases of breast lesions comprising of inflammatory, benign & malignant. Results were compared with histopathology. STATISTICAL ANALYSIS USED: Sensitivity, specificity, positive predictive value an d negative predictive value . RESULTS : Out of 100 cases, 50 cases were diagnosed as benign and 50 cases as malignant lesions on imprint smear . Fibroadenoma (26% was the most common benign lesion and invasive ductal carcinoma ( 38% was the most common malig nant lesion. The sensitivity and specificity of imprint cytology were 98% and 96.1% respectively. 96% PPV, 98% NPV and 97% overall diagnostic accuracy was observed for imprint cytology in the present study. CONCLUSIONS: Imprint cytology is a simple, accurate, rapid & cost effective diagnostic tool used intra operatively, where in facilities for frozen sections are not available. KEYWORDS : Imprint; histopathology; benign ; malignant; breast.

  15. Shape recognition of microbial cells by colloidal cell imprints

    Science.gov (United States)

    Borovička, Josef; Stoyanov, Simeon D.; Paunov, Vesselin N.

    2013-08-01

    We have engineered a class of colloids which can recognize the shape and size of targeted microbial cells and selectively bind to their surfaces. These imprinted colloid particles, which we called ``colloid antibodies'', were fabricated by partial fragmentation of silica shells obtained by templating the targeted microbial cells. We successfully demonstrated the shape and size recognition between such colloidal imprints and matching microbial cells. High percentage of binding events of colloidal imprints with the size matching target particles was achieved. We demonstrated selective binding of colloidal imprints to target microbial cells in a binary mixture of cells of different shapes and sizes, which also resulted in high binding selectivity. We explored the role of the electrostatic interactions between the target cells and their colloid imprints by pre-coating both of them with polyelectrolytes. Selective binding occurred predominantly in the case of opposite surface charges of the colloid cell imprint and the targeted cells. The mechanism of the recognition is based on the amplification of the surface adhesion in the case of shape and size match due to the increased contact area between the target cell and the colloidal imprint. We also tested the selective binding for colloid imprints of particles of fixed shape and varying sizes. The concept of cell recognition by colloid imprints could be used for development of colloid antibodies for shape-selective binding of microbes. Such colloid antibodies could be additionally functionalized with surface groups to enhance their binding efficiency to cells of specific shape and deliver a drug payload directly to their surface or allow them to be manipulated using external fields. They could benefit the pharmaceutical industry in developing selective antimicrobial therapies and formulations.

  16. Imprinting, learning and development: from behaviour to brain and back.

    Science.gov (United States)

    Bolhuis, J J; Honey, R C

    1998-07-01

    Neural and behavioural analyses have shown that the formation of filial preferences in young, precocial birds involves at least two separate processes. One process is an emerging predisposition to approach stimuli with the characteristics of the natural mother. The other (learning) process of filial imprinting results in chicks preferentially-approaching a stimulus to which they have been exposed and involves forming links between the components of the exposed stimulus. The neural substrate for the predisposition is different from that underlying imprinting, and different regions of the chick brain are involved in distinct aspects of learning about imprinting stimuli.

  17. Dummy molecularly imprinted mesoporous silica prepared by hybrid imprinting method for solid-phase extraction of bisphenol A.

    Science.gov (United States)

    Yu, Dan; Hu, Xiaolei; Wei, Shoutai; Wang, Qiang; He, Chiyang; Liu, Shaorong

    2015-05-29

    A novel hybrid dummy imprinting strategy was developed to prepare a mesoporous silica for the solid-phase extraction (SPE) of bisphenol A (BPA). A new covalent template-monomer complex (BPAF-Si) was first synthesized with 2,2-bis(4-hydroxyphenyl)hexafluoropropane (BPAF) as the template. The imprinted silica was obtained through the gelation of BPAF-Si with tetraethoxysilane and the subsequent removal of template by thermal cleavage, and then it was characterized by FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption isotherms. Results showed that the new silica had micron-level particle size and ordered mesoporous structure. The static binding test verified that the imprinted silica had much higher recognition ability for BPA than the non-imprinted silica. The imprinted silica also showed high extraction efficiencies and high enrichment factor for SPE of BPA. Using the imprinted silica, a SPE-HPLC-UV method was developed and successfully applied for detecting BPA in BPA-spiked tap water and lake water samples with a recovery of 99-105%, a RSD of 2.7-5.0% and a limit of detection (S/N=3) of 0.3ng/mL. The new imprinted silica avoided the interference of the residual template molecules and reduced the non-specific binding sites, and therefore it can be utilized as a good sorbent for SPE of BPA in environmental water samples.

  18. Molecularly imprinted polymers: synthetic receptors in bioanalysis.

    Science.gov (United States)

    Tse Sum Bui, Bernadette; Haupt, Karsten

    2010-11-01

    Molecularly imprinted polymers (MIPs) are tailor-made synthetic materials possessing specific cavities designed for a target molecule. Since they recognise their target analyte with affinities and selectivities comparable to those of antibody-antigen, enzyme-substrate and ligand-receptor interactions, they are often referred to as synthetic receptors or plastic antibodies. In this review, we describe the great potential and recent developments of MIPs in affinity separations, with emphasis on their application to the solid-phase extraction (SPE) of analytes from complex matrices. Research efforts made in this field to obtain water-compatible polymers for their applicability in aqueous environments are described. We particularly discuss problems encountered in the use of MIPs in SPE and the attempts carried out to improve their efficiency.

  19. Exploration of hydroxymethylation in Kagami-Ogata syndrome caused by hypermethylation of imprinting control regions.

    Science.gov (United States)

    Matsubara, Keiko; Kagami, Masayo; Nakabayashi, Kazuhiko; Hata, Kenichiro; Fukami, Maki; Ogata, Tsutomu; Yamazawa, Kazuki

    2015-01-01

    5-Hydroxymethylcytosine (5hmC), converted from 5-methylcytosine (5mC) by ten-eleven translocation (Tet) enzymes, has recently drawn attention as the "sixth base" of DNA since it is considered an intermediate of the demethylation pathway. Nonetheless, it remains to be addressed how 5hmC is linked to the development of human imprinting disorders. In this regard, conventional bisulfite (BS) treatment is unable to differentiate 5hmC from 5mC. It is thus hypothesized that BS conversion-derived "hypermethylation" at imprinting control regions (ICRs), which may cause imprinting disorders, would in fact be attributable to excessively increased levels of 5hmC as well as 5mC. To test this hypothesis, we applied the newly developed oxidative BS (oxBS) treatment to detect 5hmC in blood samples from Kagami-Ogata syndrome (KOS14) patients caused by an epimutation (hypermethylation) of two differentially methylated regions (DMRs) functioning as ICRs, namely, IG-DMR and MEG3-DMR. oxBS with pyrosequencing revealed that there were few amounts of 5hmC at the hypermethylated IG-DMR and MEG3-DMR in blood samples from KOS14 patients. oxBS with genome-wide methylation array demonstrated that global levels of 5hmC were very low with similar distribution patterns in blood samples from KOS14 patients and normal controls. We also confirmed the presence of large amounts of 5hmC in the brain sample from a normal control. 5hmC is not a major component in abnormally hypermethylated ICRs or at a global level, at least in blood from KOS14 patients. As the brain sample contained large amounts of 5hmC, the neural tissues of KOS14 patients are promising candidates for analysis in elucidating the role of 5hmC in the neurodevelopmental context.

  20. Cell shape recognition by colloidal cell imprints: Energy of the cell-imprint interaction

    Science.gov (United States)

    Borovička, Josef; Stoyanov, Simeon D.; Paunov, Vesselin N.

    2015-09-01

    The results presented in this study are aimed at the theoretical estimate of the interactions between a spherical microbial cell and the colloidal cell imprints in terms of the Derjaguin, Landau, Vervey, and Overbeek (DLVO) surface forces. We adapted the Derjaguin approximation to take into account the geometry factor in the colloidal interaction between a spherical target particle and a hemispherical shell at two different orientations with respect to each other. We took into account only classical DLVO surface forces, i.e., the van der Waals and the electric double layer forces, in the interaction of a spherical target cell and a hemispherical shell as a function of their size ratio, mutual orientation, distance between their surfaces, their respective surface potentials, and the ionic strength of the aqueous solution. We found that the calculated interaction energies are several orders higher when match and recognition between the target cell and the target cell imprint is achieved. Our analysis revealed that the recognition effect of the hemispherical shell towards the target microsphere comes from the greatly increased surface contact area when a full match of their size and shape is produced. When the interaction between the surfaces of the hemishell and the target cell is attractive, the recognition greatly amplifies the attraction and this increases the likelihood of them to bind strongly. However, if the surface interaction between the cell and the imprint is repulsive, the shape and size match makes this interaction even more repulsive and thus decreases the likelihood of binding. These results show that the surface chemistry of the target cells and their colloidal imprints is very important in controlling the outcome of the interaction, while the shape recognition only amplifies the interaction. In the case of nonmonotonous surface-to-surface interaction we discovered some interesting interplay between the effects of shape match and surface chemistry

  1. Synthetic strategies for the generation of molecularly imprinted organic polymers.

    Science.gov (United States)

    Mayes, A G; Whitcombe, M J

    2005-12-06

    Molecular imprinting is a method of inducing molecular recognition properties in synthetic polymers in response to the presence of a template species during formation of the three-dimensional structure of the polymer. The molecularly imprinted polymers (MIPs) prepared in this way have been termed "plastic antibodies" and combine the robustness of the polymer scaffold with binding properties more readily associated with biological receptors. Smart polymers of this type may find applications in drug delivery, controlled release and monitoring of drug and metabolite concentrations. In this review the main synthetic strategies used in the preparation of imprinted organic polymers are described in terms of the chemical principles used in the templating step. These are illustrated with examples taken from the literature and are classified as covalent, semi-covalent, non-covalent, metal-mediated and non-polar. Finally strategies for the selection of monomers, optimisation and modification of the properties of imprinted polymers are reviewed.

  2. Dimensional characterization of biperiodic imprinted structures using optical scatterometry

    KAUST Repository

    Gereige, Issam

    2013-12-01

    In this paper, we report on the characterization of biperiodic imprinted structures using a non-destructive optical technique commonly called scatterometry. The nanostructures consist of periodic arrays of square and circular dots which were imprinted in a thermoplastic polymer by thermal nanoimprint lithography. Optical measurements were performed using spectroscopic ellipsometry in the spectral region of 1.5-4 eV. The geometrical profiles of the imprinted structures were reconstructed using the Rigorous Coupled-Wave Analysis (RCWA) to model the diffraction phenomena by periodic gratings. The technique was also adapted for large scale evaluation of the imprint process. Uniqueness of the solution was examined by analyzing the diffraction of the structure at different experimental conditions, for instance at various angles of incidence. © 2013 Elsevier B.V. All rights reserved.

  3. The origin of the RB1 imprint.

    Directory of Open Access Journals (Sweden)

    Deniz Kanber

    Full Text Available The human RB1 gene is imprinted due to a differentially methylated CpG island in intron 2. This CpG island is part of PPP1R26P1, a truncated retrocopy of PPP1R26, and serves as a promoter for an alternative RB1 transcript. We show here by in silico analyses that the parental PPP1R26 gene is present in the analysed members of Haplorrhini, which comprise Catarrhini (Old World Monkeys, Small apes, Great Apes and Human, Platyrrhini (New World Monkeys and tarsier, and Strepsirrhini (galago. Interestingly, we detected the retrocopy, PPP1R26P1, in all Anthropoidea (Catarrhini and Platyrrhini that we studied but not in tarsier or galago. Additional retrocopies are present in human and chimpanzee on chromosome 22, but their distinct composition indicates that they are the result of independent retrotransposition events. Chimpanzee and marmoset have further retrocopies on chromosome 8 and chromosome 4, respectively. To examine the origin of the RB1 imprint, we compared the methylation patterns of the parental PPP1R26 gene and its retrocopies in different primates (human, chimpanzee, orangutan, rhesus macaque, marmoset and galago. Methylation analysis by deep bisulfite sequencing showed that PPP1R26 is methylated whereas the retrocopy in RB1 intron 2 is differentially methylated in all primates studied. All other retrocopies are fully methylated, except for the additional retrocopy on marmoset chromosome 4, which is also differentially methylated. Using an informative SNP for the methylation analysis in marmoset, we could show that the differential methylation pattern of the retrocopy on chromosome 4 is allele-specific. We conclude that the epigenetic fate of a PPP1R26 retrocopy after integration depends on the DNA sequence and selective forces at the integration site.

  4. Preparation of hydrophilic molecularly imprinted polymers for tetracycline antibiotics recognition

    Institute of Scientific and Technical Information of China (English)

    Peng Wang; Xiao Fang Fu; Jing Li; Jing Luo; Xiao Ya Zhao; Ming Jun Sun; Yin Zhu Shang; Cheng Ye

    2011-01-01

    Hydrophilic molecularly imprinted polymers (MIPs) were prepared using tetracycline as template, methacrylic acid as monomer and glycidilmethacrylate as pro-hydrophilic co-monomer. Compared with common MIPs, the imprinting effect and adsorption amounts of hydrophilic MIPs for tetracycline (TC) were greatly improved in water media. Furthermore, the electrochemical sensor fabricated by modifying hydrophilic MIPs on glassy carbon electrode was developed for the determination of TC in foodstuff samples.

  5. Recognition Interactions of Metal-complexing Imprinted Polymer

    Institute of Scientific and Technical Information of China (English)

    Ying LIU; Guo Sheng DING; Jun De WANG

    2005-01-01

    Molecularly imprinted polymer, exhibiting considerable enantioselectivity for L-mandelic acid, was prepared using metal coordination-chelation interaction. By evaluating the recognition characteristics in the chromatographic mode, the recognition interactions were proposed: specific and nonspecific metal coordination-chelation interaction and hydrophobic interaction were responsible for substrate binding on metal-complexing imprinted polymer; while the selective recognition only came from specific metal coordination-chelation interaction and specific hydrophobic interaction.

  6. Simultaneous Chiral SeparationUsing a Combinatorial Molecular Imprinting Phase

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Molecular imprinting chiral stationary phase against Cbz-L-Serine (Cbz-L-Ser) and Cbz-L-Alaine (Cbz-L-Ala) were prepared utilizing acrylamide + 2-vinylpyridine as combined basic functional monomers.Cross-selectivity was used to obtain simultaneous chiral separations of Cbz-DL-Ser and Cbz-DL-Ala by connecting two columns packed with Cbz-L-Ser and Cbz-L-Ala imprinted chiral stationary phase, respectively.

  7. Molecularly Imprinted Polymers for 5-Fluorouracil Release in Biological Fluids

    OpenAIRE

    Francesco Puoci; Francesca Iemma; Giuseppe Cirillo; Nevio Picci; Pietro Matricardi; Franco Alhaique

    2007-01-01

    The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs) as a controlled release device for 5-fluorouracil (5-FU) in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs). MIPs were synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic a...

  8. Synthesis of molecular imprinted beta cyclodextrins oligomers in water

    DEFF Research Database (Denmark)

    Yu, Donghong; Nielsen, Anne Louise; Bach, Lone

    2003-01-01

    hydrophobic molecules in aqueous solution, however, with limited selectivity. Templated synthesis of Cyclodextrin polymers was introduced by Komiyama. By use of simple templates, such as cholesterol, polymers with improved selectivity for the template molecules were achieved. In most...... compounds in aqueous solution and, therefore, molecular imprinting of cyclodextrins polymers in aqueous solution is of great interest. In this paper, molecular imprinting of beta cyclodextrins has been performed in water by use of diiodobenzene as template and epichlorohydrin as a crosslinker. Inclusion...

  9. Synthesis of molecular imprinted beta cyclodextrins oligomers in water

    DEFF Research Database (Denmark)

    Yu, Donghong; Nielsen, Anne Louise; Bach, Lone

    2003-01-01

    hydrophobic molecules in aqueous solution, however, with limited selectivity. Templated synthesis of Cyclodextrin polymers was introduced by Komiyama. By use of simple templates, such as cholesterol, polymers with improved selectivity for the template molecules were achieved. In most...... compounds in aqueous solution and, therefore, molecular imprinting of cyclodextrins polymers in aqueous solution is of great interest. In this paper, molecular imprinting of beta cyclodextrins has been performed in water by use of diiodobenzene as template and epichlorohydrin as a crosslinker. Inclusion...

  10. Design of molecularly imprinted polymers for diphenylamine sensing.

    Science.gov (United States)

    Granado, V L V; Rudnitskaya, A; Oliveira, J A B P; Gomes, M T S R

    2012-05-30

    A series of the polymers imprinted with diphenylamine (DPA) and respective non imprinted polymers were synthesized using precipitation polymerization. Synthesized polymers were characterized by Fourier Transform Infra-Red spectroscopy with Total Attenuated Reflectance (FTIR-ATR), Scanning Electron Microscopy (SEM) and equilibrium batch re-binding experiments. Influence of the synthesis conditions, namely monomer/template ratio and reaction duration, on the polymer binding capacity and selectivity towards aromatic compounds was investigated. Binding behavior of MIP was described using Freundlich isotherm. Significance of the effects of the synthesis conditions on the polymer properties was evaluated using ANOVA. MIPs synthesized at different conditions, which displayed different properties (binding capacity and selectivity), and respective non-imprinted polymers were employed for the fabrication of the potentiometric sensors. While sensors prepared using imprinted polymers had higher sensitivity and selectivity compared to the ones containing non-imprinted polymer, no difference was observed between sensors containing different imprinted polymers. No correspondence between polymers' characteristics obtained in the equilibrium re-binding studies and potentiometric behavior of the sensors based on the same polymers was observed. Therefore, equilibrium re-binding studies cannot be used for predicting sensor behavior.

  11. Sequences sufficient for programming imprinted germline DNA methylation defined.

    Directory of Open Access Journals (Sweden)

    Yoon Jung Park

    Full Text Available Epigenetic marks are fundamental to normal development, but little is known about signals that dictate their placement. Insights have been provided by studies of imprinted loci in mammals, where monoallelic expression is epigenetically controlled. Imprinted expression is regulated by DNA methylation programmed during gametogenesis in a sex-specific manner and maintained after fertilization. At Rasgrf1 in mouse, paternal-specific DNA methylation on a differential methylation domain (DMD requires downstream tandem repeats. The DMD and repeats constitute a binary switch regulating paternal-specific expression. Here, we define sequences sufficient for imprinted methylation using two transgenic mouse lines: One carries the entire Rasgrf1 cluster (RC; the second carries only the DMD and repeats (DR from Rasgrf1. The RC transgene recapitulated all aspects of imprinting seen at the endogenous locus. DR underwent proper DNA methylation establishment in sperm and erasure in oocytes, indicating the DMD and repeats are sufficient to program imprinted DNA methylation in germlines. Both transgenes produce a DMD-spanning pit-RNA, previously shown to be necessary for imprinted DNA methylation at the endogenous locus. We show that when pit-RNA expression is controlled by the repeats, it regulates DNA methylation in cis only and not in trans. Interestingly, pedigree history dictated whether established DR methylation patterns were maintained after fertilization. When DR was paternally transmitted followed by maternal transmission, the unmethylated state that was properly established in the female germlines could not be maintained. This provides a model for transgenerational epigenetic inheritance in mice.

  12. Molecularly Imprinted Quartz Crystal Microbalance Sensor (QCM for Bilirubin Detection

    Directory of Open Access Journals (Sweden)

    Çiğdem Çiçek

    2016-11-01

    Full Text Available This study aims the preparation of a QCM sensor for the detection of bilirubin in human plasma. Bilirubin-imprinted poly-(2-hydroxyethyl methacrylate-N-methacryloyl-l-tryptophan methyl ester (PHEMATrp nanofilm (MIP on the gold surface of a QCM chip was synthesized by the molecular imprinting technique. Meanwhile, the non-imprinted PHEMATrp (NIP nanofilm was synthesized by the same experimental technique to examine the imprinting effect. Characterization of MIP and NIP nanofilms on the QCM chip surface was achieved by atomic force microscopy (AFM, ellipsometry, Fourier transform infrared spectrophotometry-attenuated total reflectance (FTIR-ATR and contact angle measurements (CA. The observations indicated that the nanofilm was almost in a monolayer. Thereinafter, the imprinted and the non-imprinted QCM chips were connected to the QCM system to investigate kinetic and affinity properties. In order to examine the selectivity of the MIP-PHEMATrp nanofilm, competitive adsorption of bilirubin with cholesterol and estradiol was performed. Limit of detection (LOD and limit of quantitation (LOQ values were calculated as 0.45 μg/mL and 0.9 μg/mL, respectively.

  13. Electropolymerized Molecularly Imprinted Polypyrrole Film for Sensing of Clofibric Acid

    Directory of Open Access Journals (Sweden)

    Bianca Schweiger

    2015-02-01

    Full Text Available Piezoelectric quartz crystals and analogous gold substrates were electrochemically coated with molecularly imprinted polypyrrole films for pulsed amperometric detection (PAD of clofibric acid, a metabolite of clofibrate. Cyclic voltammetry data obtained during polymerization and deposited weight estimations revealed a decrease of the polymerization rate with increasing clofibric acid concentration. XPS measurements indicated that clofibric acid could be removed after imprinting with an aqueous ethanol solution, which was further optimized by using PAD. Zeta potential and contact angle measurements revealed differences between molecularly imprinted (MIP and non-imprinted polymer (NIP layers. Binding experiments with clofibric acid and other substances showed a pronounced selectivity of the MIP for clofibric acid vs. carbamazepine, but the response of MIP and NIP to 2,4-dichlorophenoxyacetic acid was higher than that for clofibric acid. A smooth surface, revealed by AFM measurements, with roughness of 6–8 nm for imprinted and non-imprinted layers, might be a reason for an excessively low density of specific binding sites for clofibric acid. Furthermore, the decreased polymerization rate in the presence of clofibric acid might not result in well-defined polymer structures, which could be the reason for the lower sensitivity.

  14. New molecular imprinted voltammetric sensor for determination of ochratoxin A

    Energy Technology Data Exchange (ETDEWEB)

    Yola, Mehmet Lütfi, E-mail: mehmetyola@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Engineering, Sinop University, Sinop (Turkey); Gupta, Vinod Kumar, E-mail: vinodfcy@iitr.ac.in [Indian Institute of Technology, Department of Chemistry, Roorkee, Roorkee 247667 (India); Department of Applied Chemistry, University of Johannesburg, Johannesburg (South Africa); Atar, Necip [Department of Chemical Engineering, Faculty of Engineering, Pamukkale University, Denizli (Turkey)

    2016-04-01

    In this report, a novel molecular imprinted voltammetric sensor based on silver nanoparticles (AgNPs) involved in a polyoxometalate (H{sub 3}PW{sub 12}O{sub 40}, POM) functionalized reduced graphene oxide (rGO) modified glassy carbon electrode (GCE) was presented for determination of ochrattoxin A (OCH). The developed surfaces were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) method. OCH imprinted GCE was prepared via electropolymerization process of 100 mM phenol as monomer in the presence of phosphate buffer solution (pH 6.0) containing 25 mM OCH. The linearity range and the detection limit of the method were calculated as 5.0 × 10{sup −11} − 1.5 × 10{sup −9} M and 1.6 × 10{sup −11} M, respectively. The voltammetric sensor was applied to grape juice and wine samples with good selectivity and recovery. The stability of the voltammetric sensor was also reported. - Highlights: • Ochratoxin A-imprinted electrochemical sensor is developed for the sensitive detection of ochratoxin A • The nanomaterial and ochratoxin A-imprinted surfaces were characterized by several methods • Ochratoxin A-imprinted electrochemical sensor is sensitive and selective in analysis of food • Ochratoxin A-imprinted electrochemical sensor is preferred to the other methods.

  15. Angelman syndrome imprinting center encodes a transcriptional promoter.

    Science.gov (United States)

    Lewis, Michael W; Brant, Jason O; Kramer, Joseph M; Moss, James I; Yang, Thomas P; Hansen, Peter J; Williams, R Stan; Resnick, James L

    2015-06-02

    Clusters of imprinted genes are often controlled by an imprinting center that is necessary for allele-specific gene expression and to reprogram parent-of-origin information between generations. An imprinted domain at 15q11-q13 is responsible for both Angelman syndrome (AS) and Prader-Willi syndrome (PWS), two clinically distinct neurodevelopmental disorders. Angelman syndrome arises from the lack of maternal contribution from the locus, whereas Prader-Willi syndrome results from the absence of paternally expressed genes. In some rare cases of PWS and AS, small deletions may lead to incorrect parent-of-origin allele identity. DNA sequences common to these deletions define a bipartite imprinting center for the AS-PWS locus. The PWS-smallest region of deletion overlap (SRO) element of the imprinting center activates expression of genes from the paternal allele. The AS-SRO element generates maternal allele identity by epigenetically inactivating the PWS-SRO in oocytes so that paternal genes are silenced on the future maternal allele. Here we have investigated functional activities of the AS-SRO, the element necessary for maternal allele identity. We find that, in humans, the AS-SRO is an oocyte-specific promoter that generates transcripts that transit the PWS-SRO. Similar upstream promoters were detected in bovine oocytes. This result is consistent with a model in which imprinting centers become DNA methylated and acquire maternal allele identity in oocytes in response to transiting transcription.

  16. Methylation and Transcripts Expression at the Imprinted GNAS Locus in Human Embryonic and Induced Pluripotent Stem Cells and Their Derivatives

    Directory of Open Access Journals (Sweden)

    Virginie Grybek

    2014-09-01

    Full Text Available Data from the literature indicate that genomic imprint marks are disturbed in human pluripotent stem cells (PSCs. GNAS is an imprinted locus that produces one biallelic (Gsα and four monoallelic (NESP55, GNAS-AS1, XLsα, and A/B transcripts due to differential methylation of their promoters (DMR. To document imprinting at the GNAS locus in PSCs, we studied GNAS locus DMR methylation and transcript (NESP55, XLsα, and A/B expression in human embryonic stem cells (hESCs and human induced pluripotent stem cells (hiPSCs derived from two human fibroblasts and their progenies. Results showed that (1 methylation at the GNAS locus DMRs is DMR and cell line specific, (2 changes in allelic transcript expression can be independent of a change in allele-specific DNA methylation, and (3 interestingly, methylation at A/B DMR is correlated with A/B transcript expression. These results indicate that these models are valuable to study the mechanisms controlling GNAS methylation, factors involved in transcript expression, and possibly mechanisms involved in the pathophysiology of pseudohypoparathyroidism type 1B.

  17. Methylation status of imprinting centers for H19/IGF2 and SNURF/SNRPN in primate embryonic stem cells.

    Science.gov (United States)

    Mitalipov, Shoukhrat; Clepper, Lisa; Sritanaudomchai, Hathaitip; Fujimoto, Akihisa; Wolf, Don

    2007-03-01

    Embryonic stem cells (ESCs) hold promise for cell and tissue replacement approaches to treating human diseases based on their capacity to differentiate into a wide variety of somatic cells and tissues. However, long-term in vitro culture and manipulations of ESCs may adversely affect their epigenetic integrity, including imprinting. We have recently reported aberrant biallelic expression of IGF2 and H19 in several rhesus monkey ESC lines, whereas SNRPN and NDN were normally imprinted and expressed predominantly from the paternal allele. The dysregulation of IGF2 and H19 that is associated with tumorigenesis in humans may result from improper maintenance of allele-specific methylation patterns at an imprinting center (IC) upstream of H19. To test this possibility, we performed methylation analysis of several monkey ESC lines by genomic bisulfite sequencing. We investigated methylation profiles of CpG islands within the IGF2/H19 IC harboring the CTCF-6 binding site. In addition, the methylation status of the IC within the promoter/exon 1 of SNURF/SNRPN known as the Prader-Willi syndrome IC was examined. Our results demonstrate abnormal hypermethylation within the IGF2/H19 IC in all analyzed ESC lines, whereas the SNURF/SNRPN IC was differentially methylated, consistent with monoallelic expression.

  18. Allele-specific deposition of macroH2A1 in Imprinting Control Regions

    Energy Technology Data Exchange (ETDEWEB)

    Choo, J H; Kim, J D; Chung, J H; Stubbs, L; Kim, J

    2006-01-13

    In the current study, we analyzed the deposition patterns of macroH2A1 at a number of different genomic loci located in X chromosome and autosomes. MacroH2A1 is preferentially deposited at methylated CpG CpG-rich regions located close to promoters. The macroH2A1 deposition patterns at the methylated CpG islands of several imprinted domains, including the Imprinting Control Regions (ICRs) of Xist, Peg3, H19/Igf2 Igf2, Gtl2/Dlk1, and Gnas domains, show consistent allele-specificity towards inactive, methylated alleles. The macroH2A1 deposition levels at the ICRs and other Differentially Methylated Regions (DMRs) of these domains are also either higher or comparable to those observed at the inactive X chromosome of female mammals. Overall, our results indicate that besides DNA methylation macroH2A1 is another epigenetic component in the chromatin of ICRs displaying differential association with two parental alleles.

  19. Imprinted X chromosome inactivation: evolution of mechanisms in distantly related mammals

    Directory of Open Access Journals (Sweden)

    Shafagh A. Waters

    2015-03-01

    Full Text Available In females, X chromosome inactivation (XCI ensures transcriptional silencing of one of the two Xs (either in a random or imprinted fashion in somatic cells. Comparing this silencing between species has offered insight into different mechanisms of X inactivation, providing clues into the evolution of this epigenetic process in mammals. Long-noncoding RNAs have emerged as a common theme in XCI of therian mammals (eutherian and marsupial. Eutherian X inactivation is regulated by the noncoding RNA product of XIST, within a cis-acting master control region called the X inactivation center (XIC. Marsupials XCI is XIST independent. Instead, XCI is controlled by the long-noncoding RNA Rsx, which appears to be a functional analog of the eutherian XIST gene, insofar that its transcript coats the inactive X and represses activity of genes in cis. In this review we discuss XCI in eutherians, and contrast imprinted X inactivation in mouse and marsupials. We provide particular focus on the evolution of genomic elements that confer the unique epigenetic features that characterize the inactive X chromosome.

  20. ATRX Plays a Key Role in Maintaining Silencing at Interstitial Heterochromatic Loci and Imprinted Genes

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    Hsiao P.J. Voon

    2015-04-01

    Full Text Available Histone H3.3 is a replication-independent histone variant, which replaces histones that are turned over throughout the entire cell cycle. H3.3 deposition at euchromatin is dependent on HIRA, whereas ATRX/Daxx deposits H3.3 at pericentric heterochromatin and telomeres. The role of H3.3 at heterochromatic regions is unknown, but mutations in the ATRX/Daxx/H3.3 pathway are linked to aberrant telomere lengthening in certain cancers. In this study, we show that ATRX-dependent deposition of H3.3 is not limited to pericentric heterochromatin and telomeres but also occurs at heterochromatic sites throughout the genome. Notably, ATRX/H3.3 specifically localizes to silenced imprinted alleles in mouse ESCs. ATRX KO cells failed to deposit H3.3 at these sites, leading to loss of the H3K9me3 heterochromatin modification, loss of repression, and aberrant allelic expression. We propose a model whereby ATRX-dependent deposition of H3.3 into heterochromatin is normally required to maintain the memory of silencing at imprinted loci.

  1. ATRX Plays a Key Role in Maintaining Silencing at Interstitial Heterochromatic Loci and Imprinted Genes.

    Science.gov (United States)

    Voon, Hsiao P J; Hughes, Jim R; Rode, Christina; De La Rosa-Velázquez, Inti A; Jenuwein, Thomas; Feil, Robert; Higgs, Douglas R; Gibbons, Richard J

    2015-04-21

    Histone H3.3 is a replication-independent histone variant, which replaces histones that are turned over throughout the entire cell cycle. H3.3 deposition at euchromatin is dependent on HIRA, whereas ATRX/Daxx deposits H3.3 at pericentric heterochromatin and telomeres. The role of H3.3 at heterochromatic regions is unknown, but mutations in the ATRX/Daxx/H3.3 pathway are linked to aberrant telomere lengthening in certain cancers. In this study, we show that ATRX-dependent deposition of H3.3 is not limited to pericentric heterochromatin and telomeres but also occurs at heterochromatic sites throughout the genome. Notably, ATRX/H3.3 specifically localizes to silenced imprinted alleles in mouse ESCs. ATRX KO cells failed to deposit H3.3 at these sites, leading to loss of the H3K9me3 heterochromatin modification, loss of repression, and aberrant allelic expression. We propose a model whereby ATRX-dependent deposition of H3.3 into heterochromatin is normally required to maintain the memory of silencing at imprinted loci.

  2. Genome scan for parent-of-origin QTL effects on bovine growth and carcass traits

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    Ikhide G. Imumorin

    2011-07-01

    Full Text Available Parent-of-origin effects (POE such as genomic imprinting influence growth and body composition in livestock, rodents and humans. Here, we report the results of a genome scan to detect quantitative trait loci (QTL with POE on growth and carcass traits in Angus x Brahman cattle crossbreds. We identified 24 POE-QTL on 15 Bos taurus autosomes (BTAs of which 6 were significant at 5% genome-wide level and 18 at the 5% chromosome-wide significance level. Six QTL were paternally expressed while 15 were maternally expressed. Three QTL influencing post-weaning growth map to the proximal end of BTA2 [linkage region of 0 – 9 cM; genomic region of 5.0 – 10.8 Mb], for which only one imprinted orthologue is known so far in the human and mouse genomes, and therefore may potentially represent a novel imprinted region. The detected QTL individually explained 1.4% ~ 5.1% of each trait’s phenotypic variance. Comparative in-silico analysis of bovine genomic locations show that 32 out of 1,442 known mammalian imprinted genes from human and mouse homologues map to the identified QTL regions. Although several of the 32 genes have been associated with quantitative traits in cattle, only 2 (GNAS and PEG3 have experimental proof of being imprinted in cattle. These results lend additional support to recent reports that POE on quantitative traits in mammals may be more common than previously thought, and strengthen the need to identify and experimentally validate cattle orthologues of imprinted genes so as to investigate their effects on quantitative traits.

  3. Genome Scan for Parent-of-Origin QTL Effects on Bovine Growth and Carcass Traits.

    Science.gov (United States)

    Imumorin, Ikhide G; Kim, Eun-Hee; Lee, Yun-Mi; De Koning, Dirk-Jan; van Arendonk, Johan A; De Donato, Marcos; Taylor, Jeremy F; Kim, Jong-Joo

    2011-01-01

    Parent-of-origin effects (POE) such as genomic imprinting influence growth and body composition in livestock, rodents, and humans. Here, we report the results of a genome scan to detect quantitative trait loci (QTL) with POE on growth and carcass traits in Angus × Brahman cattle crossbreds. We identified 24 POE-QTL on 15 Bos taurus autosomes (BTAs) of which six were significant at 5% genome-wide (GW) level and 18 at the 5% chromosome-wide (CW) significance level. Six QTL were paternally expressed while 15 were maternally expressed. Three QTL influencing post-weaning growth map to the proximal end of BTA2 (linkage region of 0-9 cM; genomic region of 5.0-10.8 Mb), for which only one imprinted ortholog is known so far in the human and mouse genomes, and therefore may potentially represent a novel imprinted region. The detected QTL individually explained 1.4 ∼ 5.1% of each trait's phenotypic variance. Comparative in silico analysis of bovine genomic locations show that 32 out of 1,442 known mammalian imprinted genes from human and mouse homologs map to the identified QTL regions. Although several of the 32 genes have been associated with quantitative traits in cattle, only two (GNAS and PEG3) have experimental proof of being imprinted in cattle. These results lend additional support to recent reports that POE on quantitative traits in mammals may be more common than previously thought, and strengthen the need to identify and experimentally validate cattle orthologs of imprinted genes so as to investigate their effects on quantitative traits.

  4. The Prader-Willi syndrome murine imprinting center is not involved in the spatio-temporal transcriptional regulation of the Necdin gene

    Directory of Open Access Journals (Sweden)

    Dandolo Luisa

    2005-01-01

    Full Text Available Abstract Background The human Prader-Willi syndrome (PWS domain and its mouse orthologue include a cluster of paternally expressed genes which imprinted expression is co-ordinately regulated by an imprinting center (IC closely associated to the Snurf-Snrpn gene. Besides their co-regulated imprinted expression, two observations suggest that the spatio-temporal expression of these genes could also be co-regulated. First, the PWS genes have all been reported to be expressed in the mouse nervous system. Second, Snurf-Snrpn and its associated IC are the most ancient elements of the domain which later acquired additional functional genes by retrotransposition. Although located at least 1.5 megabases from the IC, these retroposons acquired the same imprinted regulation as Snurf-Snrpn. In this study, we ask whether the IC, in addition to its function in imprinting, could also be involved in the spatio-temporal regulation of genes in the PWS domain. Results We compared the expression pattern of Snurf-Snrpn and C/D-box small nucleolar RNAs (snoRNAs MBII-85 and MBII-52 to the expression pattern of the two evolutionary related retroposons Ndn and Magel2, in the developing mouse embryo. We show that these genes have highly similar expression patterns in the central nervous system, suggesting that they share a common central nervous system-specific regulatory element. Among these genes, Ndn and Magel2 display the most similar expression patterns. Using transgenic mice containing the Ndn and Magel2 genes, we show that the transgenic Ndn gene whereas not imprinted is correctly expressed. Search for DNase I hypersensitive sites in the Ndn-Magel2 genomic region and comparative genomic analyses were performed in order to identify potential transcriptional cis-regulatory elements. Conclusions These results strongly suggest that paternally expressed genes of the PWS domain share a common central nervous system-specific regulatory element. We proposed that this

  5. Molecularly imprinted Ru complex catalysts integrated on oxide surfaces.

    Science.gov (United States)

    Muratsugu, Satoshi; Tada, Mizuki

    2013-02-19

    Selective catalysis is critical for the development of green chemical processes, and natural enzymes that possess specialized three-dimensional reaction pockets with catalytically active sites represent the most sophisticated systems for selective catalysis. A reaction space in an enzyme consists of an active metal center, functional groups for molecular recognition (such as amino acids), and a surrounding protein matrix to prepare the reaction pocket. The artificial design of such an integrated catalytic unit in a non-enzymatic system remains challenging. Molecular imprinting of a supported metal complex provides a promising approach for shape-selective catalysis. In this process, an imprinted cavity with a shape matched to a template molecule is created in a polymer matrix with a catalytically active metal site. In this Account, we review our studies on molecularly imprinted metal complex catalysts, focusing on Ru complexes, on oxide surfaces for shape-selective catalysis. Oxide surface-attached transition metal complex catalysts not only improve thermal stability and catalyst dispersion but also provide unique catalytic performance not observed in homogeneous precursors. We designed molecularly imprinted Ru complexes by using surface-attached Ru complexes with template ligands and inorganic/organic surface matrix overlayers to control the chemical environment around the active metal complex catalysts on oxide surfaces. We prepared the designed, molecularly imprinted Ru complexes on SiO(2) surfaces in a step-by-step manner and characterized them with solid-state (SS) NMR, diffuse-reflectance (DR) UV-vis, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller isotherm (BET), X-ray fluorescence (XRF), and Ru K-edge extended X-ray absorption fine structure (EXAFS). The catalytic performances of these Ru complexes suggest that this process of molecular imprinting facilitates the artificial integration of catalytic functions at surfaces. Further advances such

  6. Highly Selective Fluorescent Sensing of Proteins Based on a Fluorescent Molecularly Imprinted Nanosensor

    Directory of Open Access Journals (Sweden)

    Shuo Wang

    2013-09-01

    Full Text Available A fluorescent molecularly imprinted nanosensor was obtained by grafting imprinted polymer onto the surface of multi-wall carbon nanotubes and post-imprinting treatment with fluorescein isothiocyanate (FITC. The fluorescence of lysozyme-imprinted polymer (Lys-MIP was quenched more strongly by Lys than that of nonimprinted polymer (NIP, which indicated that the Lys-MIP could recognize Lys. The resulted imprinted material has the ability to selectively sense a target protein, and an imprinting factor of 3.34 was achieved. The Lys-MIP also showed selective detection for Lys among other proteins such as cytochrome C (Cyt C, hemoglobin (HB and bovine serum albumin (BSA due to the imprinted sites in the Lys-MIP. This approach combines the high selectivity of surface molecular imprinting technology and fluorescence, and converts binding events into detectable signals by monitoring fluorescence spectra. Therefore, it will have further applications for Lys sensing.

  7. Spherical molecularly imprinted polymer particles : A promising tool for molecular recognition in capillary electrokinetic separations

    NARCIS (Netherlands)

    de Boer, T; Mol, R; de Zeeuw, RA; de Jong, GJ; Sherrington, DC; Cormack, PAG; Ensing, K

    2002-01-01

    Spherical molecularly imprinted polymer particles obtained via precipitation polymerization, were introduced as a pseudostationary phase in capillary electrophoresis (CE) to study molecular recognition. Analyses were performed via a partial filling technique using (+)-ephedrine-imprinted microsphere

  8. Imprinting and flexibility in human face cognition

    Science.gov (United States)

    Marcinkowska, Urszula M.; Terraube, Julien; Kaminski, Gwenaël

    2016-01-01

    Faces are an important cue to multiple physiological and psychological traits. Human preferences for exaggerated sex typicality (masculinity or femininity) in faces depend on multiple factors and show high inter-subject variability. To gain a deeper understanding of the mechanisms underlying facial femininity preferences in men, we tested the interactive effect of family structure (birth order, sibling sex-ratio and number of siblings) and parenthood status on these preferences. Based on a group of 1304 heterosexual men, we have found that preference for feminine faces was not only influenced by sibling age and sex, but also that fatherhood modulated this preference. Men with sisters had a weaker preference for femininity than men with brothers, highlighting a possible effect of a negative imprinting-like mechanism. What is more, fatherhood increased strongly the preference for facial femininity. Finally, for fathers with younger sisters only, the more the age difference increased between them, the more femininity preference increased. Overall our findings bring new insight into how early-acquired experience at the individual level may determine face preference in adulthood, and what is more, how these preferences are flexible and potentially dependent on parenthood status in adult men. PMID:27680495

  9. Chemical microsensors with molecularly imprinted sensitive layers

    Science.gov (United States)

    Dickert, Franz L.; Greibl, Wolfgang; Sikorski, Renatus; Tortschanoff, Matthias; Weber, K.; Bulst, W. E.; Fischerauer, G.

    1998-12-01

    The bottleneck in the development of chemical sensors is the design of the coatings for chemical recognition of the analyte. One pronounced method is to tailor supramolecular cavities for different analytes. Polyfunctional linkers or the embedding of these materials in a polymeric matrix can improve stability and response time of the sensor. An even more favorable method to synthesize chemically sensitive layers is realized by molecular imprinting, since a rigid polymer can be generated directly on the transducer of interest and may be included in its production process. The analyte of interest acts as a template during the polymerization process and is evaporated or extracted by suitable solvents. Due to the cavities formed this polymer enriches analyte molecules, which can be detected by mass- sensitive devices such as QMB or SAW resonators or by optical measurements. This procedure allows both the detection of polycyclic aromatic hydrocarbons (PAHs) with fluorescence or mass sensitive devices. If the print PAHs are varied the polymers are tuned to the desired analyte. The enrichment of solvent vapors or other uncolored specimen by the layer can also be followed by the embedding of carbenium ions used as optical labels.

  10. A Zipper-Like On/Off-Switchable Molecularly Imprinted Polymer

    OpenAIRE

    Li, Songjun; Ge, Yi; Piletsky, Sergey A.; Turner, Anthony

    2011-01-01

    A zipper-like on/off-switchable molecularly imprinted polymer is reported. This unique imprinted polymer was composed of template-imprinted polymeric networks that incorporate zipper-like interactions between poly(acrylamide) (PAAm) and poly(2-acrylamide-2-methyl propanesulfonic acid) (PAMPS). This polymer showed marginal recognition ability towards the imprint species under low temperature conditions, due to the interpolymer interaction between PAAm and PAMPS, which inhibited access to the i...

  11. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Directory of Open Access Journals (Sweden)

    Catia Algieri

    2014-07-01

    Full Text Available An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported.

  12. Molecularly Imprinted Polymers for 5-Fluorouracil Release in Biological Fluids

    Directory of Open Access Journals (Sweden)

    Franco Alhaique

    2007-04-01

    Full Text Available The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs as a controlled release device for 5-fluorouracil (5-FU in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs. MIPs were synthesized using methacrylic acid (MAA as functional monomer and ethylene glycol dimethacrylate (EGDMA as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic and aqueous media was evaluated. An in vitro release study was performed both in gastrointestinal and in plasma simulating fluids. The imprinted polymers bound much more 5-Fu than the corresponding non-imprinted ones and showed a controlled/sustained drug release, with MIPs release rate being indeed much more sustained than that obtained from NIPs. These polymers represent a potential valid system for drug delivery and this study indicates that the selective binding characteristic of molecularly imprinted polymers is promising for the preparation of novel controlled release drug dosage form.

  13. Chitosan in Molecularly-Imprinted Polymers: Current and Future Prospects.

    Science.gov (United States)

    Xu, Long; Huang, Yun-An; Zhu, Qiu-Jin; Ye, Chun

    2015-08-07

    Chitosan is widely used in molecular imprinting technology (MIT) as a functional monomer or supporting matrix because of its low cost and high contents of amino and hydroxyl functional groups. The various excellent properties of chitosan, which include nontoxicity, biodegradability, biocompatibility, and attractive physical and mechanical performances, make chitosan a promising alternative to conventional functional monomers. Recently, chitosan molecularly-imprinted polymers have gained considerable attention and showed significant potential in many fields, such as curbing environmental pollution, medicine, protein separation and identification, and chiral-compound separation. These extensive applications are due to the polymers' desired selectivity, physical robustness, and thermal stability, as well as their low cost and easy preparation. Cross-linkers, which fix the functional groups of chitosan around imprinted molecules, play an important role in chitosan molecularly-imprinted polymers. This review summarizes the important cross-linkers of chitosan molecularly-imprinted polymers and illustrates the cross-linking mechanism of chitosan and cross-linkers based on the two glucosamine units. Finally, some significant attempts to further develop the application of chitosan in MIT are proposed.

  14. Molecularly imprinted polymers for 5-fluorouracil release in biological fluids.

    Science.gov (United States)

    Puoci, Francesco; Iemma, Francesca; Cirillo, Giuseppe; Picci, Nevio; Matricardi, Pietro; Alhaiqu, Franco

    2007-04-18

    The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs) as a controlled release device for 5-fluorouracil (5-FU) in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs). MIPs were synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic and aqueous media was evaluated. An in vitro release study was performed both in gastrointestinal and in plasma simulating fluids. The imprinted polymers bound much more 5-Fu than the corresponding non-imprinted ones and showed a controlled/sustained drug release, with MIPs release rate being indeed much more sustained than that obtained from NIPs. These polymers represent a potential valid system for drug delivery and this study indicates that the selective binding characteristic of molecularly imprinted polymers is promising for the preparation of novel controlled release drug dosage form.

  15. Creating BHb-imprinted magnetic nanoparticles with multiple binding sites.

    Science.gov (United States)

    Li, Yanxia; Chen, Yiting; Huang, Lu; Lou, BenYong; Chen, Guonan

    2017-01-16

    A kind of protein imprinted over magnetic Fe3O4@Au multifunctional nanoparticles (NPs) with multiple binding sites was synthesized and investigated. Magnetic Fe3O4@Au NPs as carrier materials were modified with 4-mercaptophenylboronic acid (MPBA) and mercaptopropionic acid (MPA) to introduce boronic acids and carboxyl groups. Using Bovine Hemoglobin (BHb) as a template, a polydopamine(PDA)-based molecular imprinted film was fabricated to produce a kind of magnetic molecularly imprinted nanoparticle (MMIP), possessing multiple binding sites with benzene-diol, amino groups, boronic acids and carboxyl groups. The MMIPs exhibited an excellent imprinting effect and adsorption capacity (89.65± 0.38 mg g(-1)) toward the template protein. The results show that the MMIPs reached saturated adsorption at 0.5 mg mL(-1) within 90 min. The synthesized MMIPs are suitable for the removal and enrichment of the template protein in proteomics. The strategy of multiple binding sites paves the way for the preparation of functional nanomaterials in molecular imprinting techniques.

  16. Scalemic and racemic imprinting with a chiral crosslinker.

    Science.gov (United States)

    Hebert, Britney; Meador, Danielle S; Spivak, David A

    2015-08-26

    The development of molecularly imprinted chiral stationary phases has traditionally been limited by the need for a chiral pure template. Paradoxically, availability of a chiral pure template largely defeats the purpose of developing a chiral stationary phase. To solve this paradox, imprinting of scalemic and racemic template mixtures was investigated using both chiral (N-α-bismethacryloyl-L-alanine) and achiral (N,O-bisacrylamide ethanolamine) crosslinkers. Imprinting of scalemic mixtures provided polymers capable of partial separation of Boc-tyrosine enantiomers with virtually the same results when using either the chiral or achiral crosslinker. However, the chiral crosslinker was required for chiral differentiation by the racemic imprinted polymers which were evaluated in both batch rebinding and chromatographic modes. Batch rebinding analysis revealed intersecting binding isotherms for the L- and D-Boc-tyrosine, indicating bias for the D or L enantiomer is concentration dependent. Partial chromatographic separation was achieved by the racemic imprinted polymers providing variable D or L bias in equal probability over multiple replicates of polymer synthesis. Correlation of enantiomer bias with the batch rebinding results and optimization of HPLC parameters are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Electrosynthesis of molecularly imprinted polypyrrole for the antibiotic levofloxacin

    Energy Technology Data Exchange (ETDEWEB)

    Mazzotta, Elisabetta, E-mail: elisabetta.mazzotta@unisalento.it [Laboratorio di Chimica Analitica, Dipartimento di Scienza dei Materiali, Universita del Salento, via Monteroni 73100 Lecce (Italy); Malitesta, Cosimino [Laboratorio di Chimica Analitica, Dipartimento di Scienza dei Materiali, Universita del Salento, via Monteroni 73100 Lecce (Italy); Diaz-Alvarez, Myriam; Martin-Esteban, Antonio [Departamento de Medio Ambiente, INIA, Carretera de A Coruna km 7.5, 28240 Madrid (Spain)

    2012-01-01

    The development of an electrosynthesized imprinted polypyrrole (PPY) film onto a platinum sheet as sorbent phase for a fluoroquinolone antibiotic (levofloxacin) is described. Experimental conditions for the electropolymerization of PPY in the presence of the template were optimized. The molecularly imprinted polymer (MIP) film was characterized by X-Ray Photoelectron Spectroscopy (XPS) to verify the template entrapment in the polymeric matrix. After being subject to washing procedures, MIP was analyzed by XPS and a very satisfactory template removal was estimated being equal to 83%. The effectiveness of washing protocol was assessed also by UV-vis and High Performance Liquid Chromatography (HPLC) analysis of corresponding washing solutions. Rebinding experiments were performed by exposing the imprinted PPY film to levofloxacin solutions, subsequently analyzed by HPLC. The effect of solvent and time of exposure was investigated. The imprinting effect was verified by comparing recognition abilities of both MIP and not imprinted polymer (a polymer prepared in the same conditions but in the absence of the template).

  18. Polymer Catalysts Imprinted with Metal Ions as Biomimics of Metalloenzymes

    Directory of Open Access Journals (Sweden)

    Joanna Czulak

    2013-01-01

    Full Text Available This work presents the preparation and properties of molecularly imprinted polymers (MIPs with catalytic centers that mimic the active sites of metalloenzymes. The MIP synthesis was based on suspension polymerization of functional monomers (4-vinylpyridine and acrylonitrile with trimethylolpropane trimethacrylate as a crosslinker in the presence of transition metal ions and 4-methoxybenzyl alcohol as a template. Four metal ions have been chosen for imprinting from among the microelements that are the most essential in the native enzymes: Cu2+, Co2+, Mn2+, and Zn2+. To prepare catalysts, the required loading of metal ions was obtained during sorption process. The catalysts imprinted with Cu2+, Co2+, and Zn2+ were successfully used for hydroquinone oxidation in the presence of hydrogen peroxide. The Mn2+-imprinted catalyst showed no activity due to the insufficient metal loading. Cu2+ MIP showed the highest efficiency. In case of Cu- and Co-MIP catalysts, their activity was additionally increased by the use of surface imprinting technique.

  19. Chitosan in Molecularly-Imprinted Polymers: Current and Future Prospects

    Directory of Open Access Journals (Sweden)

    Long Xu

    2015-08-01

    Full Text Available Chitosan is widely used in molecular imprinting technology (MIT as a functional monomer or supporting matrix because of its low cost and high contents of amino and hydroxyl functional groups. The various excellent properties of chitosan, which include nontoxicity, biodegradability, biocompatibility, and attractive physical and mechanical performances, make chitosan a promising alternative to conventional functional monomers. Recently, chitosan molecularly-imprinted polymers have gained considerable attention and showed significant potential in many fields, such as curbing environmental pollution, medicine, protein separation and identification, and chiral-compound separation. These extensive applications are due to the polymers’ desired selectivity, physical robustness, and thermal stability, as well as their low cost and easy preparation. Cross-linkers, which fix the functional groups of chitosan around imprinted molecules, play an important role in chitosan molecularly-imprinted polymers. This review summarizes the important cross-linkers of chitosan molecularly-imprinted polymers and illustrates the cross-linking mechanism of chitosan and cross-linkers based on the two glucosamine units. Finally, some significant attempts to further develop the application of chitosan in MIT are proposed.

  20. Molecularly imprinted polymers as the future drug delivery devices.

    Science.gov (United States)

    Luliński, Piotr

    2013-01-01

    In recent years, the investigations of new drug delivery systems have been directed on the development of some "intelligent" drug delivery devices that are able to directly respond to the patient's individual needs. New drug delivery systems should maximize the efficiency of administrated therapeutic agents and improve the patient's quality of life. Introduction of the new drug delivery devices is an important scientific goal, which could be achieved by combining new technologies and intelligent biomaterials. Molecular imprinting technology has a high potential for the preparation of optimized drug delivery forms. Here, molecularly imprinted polymers (MIPs) are promising new materials for such purposes, but their application in this field is nowadays at a developing stage. In this review, the principles of molecular imprinting and the recognition-release mechanisms of polymeric matrices are discussed. The potential application of molecularly imprinted materials as the future drug delivery systems with various administering routes (transdermal, ocular or oral) are presented, and some future prospects for the imprinted polymers are outlined.

  1. Quantum-dots-encoded-microbeads based molecularly imprinted polymer.

    Science.gov (United States)

    Liu, Yixi; Liu, Le; He, Yonghong; He, Qinghua; Ma, Hui

    2016-03-15

    Quantum dots encoded microbeads have various advantages such as large surface area, superb optical properties and the ability of multiplexing. Molecularly imprinted polymer that can mimic the natural recognition entities has high affinity and selectivity for the specific analyte. Here, the concept of utilizing the quantum dots encoded microbeads as the supporting material and the polydopamine as the functional monomer to form the core-shell molecular imprinted polymer was proposed for the first time. The resulted imprinted polymer can provide various merits: polymerization can complete in aqueous environment; fabrication procedure is facile and universal; the obvious economic advantage; the thickness of the imprinting layer is highly controllable; polydopamine coating can improve the biocompatibility of the quantum dot encoded microbeads. The rabbit IgG binding and flow cytometer experiment result showed the distinct advantages of this strategy: cost-saving, facile and fast preparation procedure. Most importantly, the ability for the multichannel detection, which makes the imprinted polydopamine modified encoded-beads very attractive in protein pre-concentration, recognition, separation and biosensing. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Sexual imprinting: what strategies should we expect to see in nature?

    Science.gov (United States)

    Chaffee, Dalton W; Griffin, Hayes; Gilman, R Tucker

    2013-12-01

    Sexual imprinting occurs when juveniles learn mate preferences by observing the phenotypes of other members of their populations, and it is ubiquitous in nature. Imprinting strategies, that is which individuals and phenotypes are observed and how strong preferences become, vary among species. Imprinting can affect trait evolution and the probability of speciation, and different imprinting strategies are expected to have different effects. However, little is known about how and why different imprinting strategies evolve, or which strategies we should expect to see in nature. We used a mathematical model to study how the evolution of sexual imprinting depends on (1) imprinting costs and (2) the sex-specific fitness effects of the phenotype on which individuals imprint. We found that even small fixed costs prevent the evolution of sexual imprinting, but small relative costs do not. When imprinting does evolve, we identified the conditions under which females should evolve to imprint on their fathers, their mothers, or on other members of their populations. Our results provide testable hypotheses for empirical work and help to explain the conditions under which sexual imprinting might evolve to promote speciation. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  3. 21 CFR 330.3 - Imprinting of solid oral dosage form drug products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Imprinting of solid oral dosage form drug products... AS SAFE AND EFFECTIVE AND NOT MISBRANDED General Provisions § 330.3 Imprinting of solid oral dosage form drug products. A requirement to imprint an identification code on solid oral dosage form drug...

  4. Synthesis of Molecularly Imprinted Polymer Particles by Suspension Polymerization in Silicon Oil

    Institute of Scientific and Technical Information of China (English)

    Xiao Bing WANG; Zhao Hui ZHENG; Xiao Bin DING; Xu CHENG; Xin Hua HU; Yu Xing PENG

    2006-01-01

    Molecularly imprinted polymers using 2,4-dichlorophenoxyacetic acid (2,4-D) as templates were prepared by suspension polymerization in silicon oil. The polymer particles exhibited regular shape in the micro-scale range. The adsorbing experiments indicated that the imprinted polymer particles possessed higher affinity to 2,4-D than the non-imprinted polymer particles.

  5. Transcription factor CTCF and mammalian genome organization

    Directory of Open Access Journals (Sweden)

    Kotova E. S.

    2014-07-01

    Full Text Available The CTCF transcription factor is thought to be one of the main participants in various gene regulatory networks including transcription activation and repression, formation of independently functioning chromatin domains, regulation of imprinting etc. Sequencing of human and other genomes opened up a possibility to ascertain the genomic distribution of CTCF binding sites and to identify CTCF-dependent cis-regulatory elements, including insulators. In the review, we summarized recent data on CTCF functioning within a framework of the chromatin loop domain hypothesis of large-scale regulation of the genome activity. Its fundamental properties allow CTCF to serve as a transcription factor, an insulator protein and a dispersed genome-wide demarcation tool able to recruit various factors that emerge in response to diverse external and internal signals, and thus to exert its signal-specific function(s.

  6. The utility of quantitative methylation assays at imprinted genes for the diagnosis of fetal and placental disorders.

    Science.gov (United States)

    Bourque, D K; Peñaherrera, M S; Yuen, R K C; Van Allen, M I; McFadden, D E; Robinson, W P

    2011-02-01

    An imbalance of imprinted gene expression within 11p15.5 is observed in Beckwith-Wiedemann syndrome (BWS), as well as in a variety of placental abnormalities including complete hydatidiform mole (CHM), placental mesenchymal dysplasia (PMD) and triploidy. To facilitate the diagnosis of epigenetic errors and chromosomal imbalance of 11p15.5, we validated a pyrosequencing assay to measure methylation at KvDMR1 using blood samples from 13 BWS cases, 8 of which showed reduced methylation as compared to control blood. An imbalance between maternal and paternal genomes as is found in triploidy, CHM or PMD was also associated with altered KvDMR1 methylation. A reciprocal pattern of methylation was obtained in the triploid cases by assaying the proximal 11p15.5 ICR associated with H19. To distinguish chromosome 11 specific alterations from whole genome imbalance, other imprinted differentially methylated regions (DMRs) can be utilized. Thus, pyrosequencing assays for DMRs associated with SGCE, SNRPN, and MEST were also compared for their utility in diagnosing parental imbalance in placental samples. While each of these assays could successfully distinguish parental origin of triploidy, SGCE showed the clearest separation between groups. The combined use of a chromosome 11p15.5 assay (e.g. KvDMR1 or H19-ICR) and non-chromosome 11 assay (e.g. SGCE) provides a potentially valuable diagnostic tool in the rapid screening of methylation errors in placental disorders. These results also show the maintenance of imprinting status at these loci in the human placenta, even in the presence of abnormal pathology.

  7. Preparation and recognition performance of cytisine alkaloid-imprinted material prepared using novel surface molecular imprinting technique.

    Science.gov (United States)

    Gao, Baojiao; Niu, Qinyuan; Du, Ruikui

    2010-05-01

    Methacrylic acid was first graft-polymerized on the surfaces of micron-sized silica gel particles in the manner of "grafting from" using 3-methacryloxypropyl trimethoxysilane as an intermedia, obtaining the grafted particle polymethacrylic acid PMAA/SiO(2). By adopting the novel surface-molecular imprinting technique put forward by us, cytisine molecule-imprinted material MIP-PMAA/SiO(2) was prepared with ethylene glycol diglycidyl ether as crosslinking agent. The binding characteristics of MIP-PMAA/SiO(2) towards cytisine was investigated in depth with both batch and column methods and using matrine and oxymatrine as two contrast alkaloids, which with cytisine coexist in sophora alopecuroides and their chemical structure is similar to cytisine to a certain extent. The experimental results show that the surface-imprinted material MIP-PMAA/SiO(2) has excellent binding affinity for cytisine (20.1 g/100 g of binding capacity), and it is more important that MIP-PMAA/SiO(2) has very high recognition selectivity for cytisine in relation to the two contrast alkaloids. The selectivity coefficients of the grafted particles PMAA/SiO(2) (non-imprinted material) for cytosine in relation to matrine and oxymatrine are only 1.03 and 1.06, respectively, displaying no recognition selectivity for cytisine. However, after imprinting, the selectivity coefficient of MIP-PMAA/SiO(2) for cytisine in respect to matrine and oxymatrine are remarkably enhanced to 12.08 and 15.05, respectively.

  8. Modular Polymer Biosensors by Solvent Immersion Imprint Lithography

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Jayven S.; Xantheas, Sotiris S.; Grate, Jay W.; Wietsma, Thomas W.; Gratton, Enrico; Vasdekis, Andreas

    2016-01-01

    We recently demonstrated Solvent Immersion Imprint Lithography (SIIL), a rapid benchtop microsystem prototyping technique, including polymer functionalization, imprinting and bonding. Here, we focus on the realization of planar polymer sensors using SIIL through simple solvent immersion without imprinting. We describe SIIL’s impregnation characteristics, including an inherent mechanism that not only achieves practical doping concentrations, but their unexpected 4-fold enhancement compared to the immersion solution. Subsequently, we developed and characterized optical sensors for detecting molecular O2. To this end, a high dynamic range is reported, including its control through the immersion duration, a manifestation of SIIL’s modularity. Overall, SIIL exhibits the potential of improving the operating characteristics of polymer sensors, while significantly accelerating their prototyping, as it requires a few seconds of processing and no need for substrates or dedicated instrumentation. These are critical for O2 sensing as probed by way of example here, as well as any polymer permeable reactant.

  9. Synthesis of magnetic cytosine-imprinted chitosan nanoparticles

    Science.gov (United States)

    Lee, Mei-Hwa; Ahluwalia, Arti; Chen, Jian-Zhou; Shih, Neng-Lang; Lin, Hung-Yin

    2017-02-01

    Molecularly imprinted polymer nanoparticles incorporating magnetic nanoparticles (MNPs) have been investigated for their selective adsorption properties. Here we describe the synthesis and characterization of magnetic cytosine-imprinted chitosan nanoparticles (CIPs) for gene delivery. In particular, CIPs carrying the mammalian expression plasmid of enhanced green fluorescent protein were prepared by the co-precipitation of MNPs, chitosan and a template nucleobase (cytosine). The results show that the selective reabsorption of cytosine to magnetic CIPs was at least double that of non-imprinted polymers and other nucleobases (such as adenine and thymine). The gene carrier CIPs were used for the transfection of human embryonic kidney 293 cells showing dramatic increase their efficiency with that of conventional chitosan nanoparticles. Furthermore, the gene carrier magnetic CIPs also exhibit low toxicity compared to that of commercially available cationic lipids.

  10. Measurement of ablative Richtmyer-Meshkov evolution from laser imprint

    Science.gov (United States)

    Martinez, D. A.; Smalyuk, V. A.; Igumenshchev, I. V.; Delorme, B.; Casner, A.; Masse, L.; Park, H.-S.; Remington, B. A.; Olazabal-Loumé, M.

    2017-10-01

    Experiments were performed to investigate the ablative Richtmyer-Meshkov (RM) instability in plastic (CH2) foils. The two-dimensional (2-D) perturbations were created by laser imprinting using a special phase plate with a 2-D single mode, ˜70 μm wavelength sinusoidal intensity pattern on the plastic foil. The growth of imprinted perturbations was measured by face-on, X-ray radiography using Sm and Ta backlighters in 30-μm and 50-μm thick plastic foils, respectively. After the initial imprinting phase, the 2-D perturbations grew due to ablative RM instability before the onset of foil acceleration when they were further amplified by Rayleigh-Taylor instability. Experimental results agree reasonably well with 2-D hydrodynamic simulations and analytic models showing that the modulation growth in areal density is due to ablative RM instability.

  11. Tunable and stable in time ferroelectric imprint through polarization coupling

    Directory of Open Access Journals (Sweden)

    Anirban Ghosh

    2016-06-01

    Full Text Available Here we demonstrate a method to tune a ferroelectric imprint, which is stable in time, based on the coupling between the non-switchable polarization of ZnO and switchable polarization of PbZrxTi(1−xO3. SrRuO3/PbZrxTi(1−xO3/ZnO/SrRuO3 heterostructures were grown with different ZnO thicknesses. It is shown that the coercive voltages and ferroelectric imprint vary linearly with the thickness of ZnO. It is also demonstrated that the ferroelectric imprint remains stable with electric field cycling and electric field stress assisted aging.

  12. Imprinting of IGF2 P0 transcript and novel alternatively spliced INS-IGF2 isoforms show differences between mouse and human.

    Science.gov (United States)

    Monk, D; Sanches, R; Arnaud, P; Apostolidou, S; Hills, F A; Abu-Amero, S; Murrell, A; Friess, H; Reik, W; Stanier, P; Constância, M; Moore, G E

    2006-04-15

    Genomic imprinting is limited to a subset of genes that play critical roles in fetal growth, development and behaviour. One of the most studied imprinted genes encodes insulin-like growth factor 2, and aberrant imprinting and DNA methylation of this gene is associated with the growth disorders Beckwith-Wiedemann and Silver-Russell syndromes and many human cancers. Specific isoforms of this gene have been shown to be essential for normal placental function, as mice carrying paternal null alleles for the Igf2-P0 transcript are growth restricted at birth. We report here the identification of three novel human transcripts from the IGF2 locus. One is equivalent to the mouse Igf2-P0 transcript, whereas the two others (INSIGF long and short) originate from the upstream INS gene that alternatively splices to downstream IGF2 exons. In order to elucidate the molecular mechanisms involved in the complex imprinting of these novel IGF2 transcripts, both the allele-specific expression and methylation for all the IGF2 promoters including P0 and the INSIGF transcripts were analysed in human tissues. Similar to the mouse, the human IGF2-P0 transcript is paternally expressed; however, its expression is not limited to placenta. This expression correlates with tissue-specific promoter methylation on the maternal allele. The two novel INSIGF transcripts reported here use the INS promoter and show highly restricted tissue expression profiles including the pancreas. As previously reported for INS in the yolk sac, we demonstrate complex, tissue-specific imprinting of these transcripts. The finding of additional transcripts within this locus will have important implications for IGF2 regulation in both cancer and metabolism.

  13. Synthesis and Characterization of Molecularly Imprinted Polymers for Phenoxyacetic Acids

    Directory of Open Access Journals (Sweden)

    Canping Pan

    2008-01-01

    Full Text Available 2-methylphenoxyacetic acid (2-MPA, 2-methyl-4-chlorophenxyacetic acid (MCPA and 4-chlorophenoxyacetic acid (4-CPA were imprinted to investigate the cross-selectivities of molecularly imprinted polymers (MIPs. The result indicates that 2-MPA, which is similar in shape, size and functionality with phenoxyacetic herbicides, are suitable to be used as a suitable template to prepare the MIPs for retaining phenoxyacetic herbicides. To study the ion-pair interactions between template molecules and functional monomer 4-vinylpiridine (4-VP, computational molecular modeling was employed. The data indicate that the cross-selectivities of MIPs for phenoxyacetic acid herbicides depend on the binding energies of complexes.

  14. Quantification and confocal imaging of protein specific molecularly imprinted polymers

    OpenAIRE

    Hawkins, DM; Trache, A; Ellis, EA; Stevenson, D.; Holzenburg, A.; Meininger, GA; Reddy, Subrayal M

    2006-01-01

    We have employed FITC-albumin as the protein template molecule in an aqueous phase molecular imprinted polymer (HydroMIP) strategy. For the first time, the use of a fluorescently labelled template is reported, with subsequent characterisation of the smart material to show that the HydroMIP possess a significant molecular memory in comparison to that of the nonimprinted control polymer (HydroNIP). The imaging of the FITC-albumin imprinted HydroMIP using confocal microscopy is described, with t...

  15. Production of abiotic receptors by molecular imprinting of proteins.

    Science.gov (United States)

    Braco, L; Dabulis, K; Klibanov, A M

    1990-01-01

    When a protein is dissolved in a concentrated aqueous solution of a multifunctional organic compound, freeze-dried, and washed with an anhydrous organic solvent to remove the ligand, the resultant "imprinted" protein preparation binds up to 30-fold more of the template compound in anhydrous solvents than the nonimprinted protein in the same solvent (and both proteins in water). These artificial receptors exhibit marked ligand selectivity as well as stability in anhydrous media. This phenomenon of molecular imprinting, demonstrated for several unrelated proteins and ligands, may be helpful in the development of unique bioadsorbents and, potentially, new biocatalysts.

  16. Early imprinting in wild and game-farm mallards (Anas platyrhynchos): genotype and arousal

    Science.gov (United States)

    Cheng, K.M.; Shoffner, R.N.; Phillips, R.E.; Shapiro, L.J.

    1979-01-01

    Early imprinting was studied under laboratory conditions in five lines of mallards (Anas platyrhynchos) with different degrees of wildness obtained through pedigreed breeding. Data were analyzed by the least squares method. Wild ducklings imprinted better than game-farm (domesticated) ducklings, and heterosis was demonstrated to exist in imprinting traits. Nonadditive genetic variations and genotype-environmental interactions are discussed as possible causes for the heterosis observed. Differences in imprinting between genetic lines are attributed, at least partly, to differences in arousal level during the ducklings' first exposure to the imprinting stimulus.

  17. Enantiomeric Resolution on L-Carnitine Selective Polymers Prepared by Molecular Imprinting

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    L-carnitine selective polymers were prepared by molecular imprinting using methacrylic acid as the functional monomer. The acid function of the monomer is expected to form hydrogen bond and ionic interactions with the amine function of the target molecule L-carnitine. The imprinted polymers were used as stationary phases in high-performance liquid chromatography (HPLC). It was shown that L-carnitine imprinted polymer exhibited a higher affinity to its template molecule, while the non-imprinted polymer had no affinity to the compounds tested. Racemic carnitine hydrochloride was efficiently resolved on the L-carnitine imprinted polymer, and the separation factor is 1.9.

  18. Enantiomeric Resolution on L—Carnitine Selective Polymers Prepared by Molecular Imprinting

    Institute of Scientific and Technical Information of China (English)

    XiaoTaoLI; GuangGuangJIANG; 等

    2002-01-01

    L-carnitine selective polymers were prepared by molecular imprinting using methacrylic acid as the functional monomer. The acid function of the monomer is expected to form hydrogen bond and ionic interactions with the amine function of the target molecule L-carnitine.The imprinted polymers were used as stationary phases in high-performance liquid chromatography (HPLC). It was shown that L-carnitine imprinted polymer exhibited a higher affinity to its template molecule,while the non-imprinted polymer had no affinity to the compounds tested. Racemic carnitine hydrochloride was efficiently resolved on the L-carnitine imprinted polymer, and the separation factor is 1.9.

  19. Binding characteristics of molecularly imprinted polymers based on fungicides in hydroalcoholic media.

    Science.gov (United States)

    Bitar, Manal; Bou-Maroun, Elias; Lerbret, Adrien; Ouaini, Naim; Cayot, Philippe

    2015-10-01

    An iprodione-imprinted polymer was prepared by copolymerization of methacrylamide and ethylene glycol dimethacrylate using a noncovalent imprinting approach. Methacrylamide was chosen using molecular dynamics simulations. To concentrate iprodione from hydro-alcoholic solutions, batch sorption of iprodione on the imprinted polymer were conducted. The equilibrium time for iprodione sorption is 20 min, and the corresponding kinetic mechanism follows the pseudo-second order indicating a strong interaction between iprodione and the imprinted polymer. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to fit the isotherm of iprodione sorption. The imprinted polymer was found to be more efficient than the nonimprinted polymer for the uptake of iprodione, as revealed by its higher adsorption energy, affinity, and capacity. Finally, a selectivity study was conducted on the imprinted and the nonimprinted polymers to sorb three fungicides. It shows that the imprinted polymer could be used as a preconcentration phase in a multiresidue analysis of fungicides in hydroalcoholic medium.

  20. Embryonic imprinting perturbations do not originate from superovulation-induced defects in DNA methylation acquisition.

    Science.gov (United States)

    Denomme, Michelle M; Zhang, Liyue; Mann, Mellissa R W

    2011-09-01

    To investigate whether superovulation disrupts maternal imprint acquisition in oocytes. Animal model. Academic institute. Spontaneously ovulated and superovulated mice. Low and high hormone dosage treatments were administered to females, and ovulated metaphase II oocytes were collected. Imprinted DNA methylation was analyzed at Snrpn, Kcnq1ot1, Peg3, and H19 in individual oocytes. Examination of 125 individual oocytes derived from females subjected to low and high hormone treatments revealed normal imprinted methylation patterns that were comparable to oocytes derived from spontaneously ovulated females. Maternal imprint acquisition was not affected by superovulation. Given its aberrant effects during preimplantation development, superovulation must instead disrupt maternal-effect gene products that are required after fertilization for imprint maintenance. These results eliminate imprint acquisition per se as the initial stage of imprint loss and point to the importance of analyses on early embryos after procedures involving oocyte manipulation. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  1. Influence of the Prader-Willi syndrome imprinting center on the DNA methylation landscape in the mouse brain

    Science.gov (United States)

    Brant, Jason O; Riva, Alberto; Resnick, James L; Yang, Thomas P

    2014-01-01

    Reduced representation bisulfite sequencing (RRBS) was used to analyze DNA methylation patterns across the mouse brain genome in mice carrying a deletion of the Prader-Willi syndrome imprinting center (PWS-IC) on either the maternally- or paternally-inherited chromosome. Within the ∼3.7 Mb imprinted Angelman/Prader-Willi syndrome (AS/PWS) domain, 254 CpG sites were interrogated for changes in methylation due to PWS-IC deletion. Paternally-inherited deletion of the PWS-IC increased methylation levels ∼2-fold at each CpG site (compared to wild-type controls) at differentially methylated regions (DMRs) associated with 5′ CpG island promoters of paternally-expressed genes; these methylation changes extended, to a variable degree, into the adjacent CpG island shores. Maternal PWS-IC deletion yielded little or no changes in methylation at these DMRs, and methylation of CpG sites outside of promoter DMRs also was unchanged upon maternal or paternal PWS-IC deletion. Using stringent ascertainment criteria, ∼750,000 additional CpG sites were also interrogated across the entire mouse genome. This analysis identified 26 loci outside of the imprinted AS/PWS domain showing altered DNA methylation levels of ≥25% upon PWS-IC deletion. Curiously, altered methylation at 9 of these loci was a consequence of maternal PWS-IC deletion (maternal PWS-IC deletion by itself is not known to be associated with a phenotype in either humans or mice), and 10 of these loci exhibited the same changes in methylation irrespective of the parental origin of the PWS-IC deletion. These results suggest that the PWS-IC may affect DNA methylation at these loci by directly interacting with them, or may affect methylation at these loci through indirect downstream effects due to PWS-IC deletion. They further suggest the PWS-IC may have a previously uncharacterized function outside of the imprinted AS/PWS domain. PMID:25482058

  2. Is Imprinting an Appropriate Model for Human Infant Attachment?

    Science.gov (United States)

    Reed, G. L.; Leiderman, P. H.

    1983-01-01

    Results of animal imprinting studies were generalized to attempt prediction of development of attachment in 28 polymatrically reared Kenyan Gusii infants, ages 6 to 30 months. While results provide evidence against a sensitive phase for attachment, an association was found between age of attachment and developmental level/caregiving history.…

  3. The Interaction Systems Generated by the Teacher's Didactic Imprinting

    Science.gov (United States)

    Peralta, Nadia S.; Roselli, Néstor D.

    2015-01-01

    The current study aimed to identify and analyze the systems of interaction implemented by teachers in university classes, based on their teaching imprints. It focused on the interactions occurred in scholar natural contexts and the construction of knowledge based on said interaction. A form to observe the different behaviors was designed in order…

  4. Imprinting of confining sites for cell cultures on thermoplastic substrates

    Science.gov (United States)

    Cone, C. D.; Fleenor, E. N.

    1969-01-01

    Prevention of test cell migration beyond the field of observation involves confining cells or cultures in microlagoons made in either a layer of grease or a thermoplastic substrate. Thermoplastic films or dishes are easily imprinted with specifically designed patterns of microlagoons.

  5. SEXUAL IMPRINTING AND SONG LEARNING - 2 OF ONE KIND

    NARCIS (Netherlands)

    TENCATE, C; VOS, DR; MANN, N

    1993-01-01

    Imprinting and song learning in birds are usually categorized under the same heading as 'exposure', 'template' or 'programmed' learning. These terms point to several similarities between the processes, but exactly how similar they are and whether the similarity implies a direct causal linkage is not

  6. STIMULUS REPRESENTATION - A SUBPROCESS OF IMPRINTING AND CONDITIONING

    NARCIS (Netherlands)

    HOLLIS, KL; TENCATE, C; BATESON, P

    1991-01-01

    We suggest a way to reconcile imprinting and associative learning that respects the real differences between the two phenomena but helps to recognize underlying commonalities. Rather than treating each type of learning as the manifestation of a unitary mechanism, we approach learning as a combinatio

  7. Molecularly imprinted polymers (MIPs): sensing, an explosive new opportunity?

    Science.gov (United States)

    McCluskey, Adam; Holdsworth, Clovia I; Bowyer, Michael C

    2007-10-21

    Our group is currently developing in-field detection systems alongside the Australian Federal Police Forensic Services utilising molecularly imprinted polymers as the recognition elements. This review looks at MIP synthesis and our perceptions of future directions from an Australian and forensic perspective.

  8. Preparation and Property Recognition of Nimodipine Molecularly Imprinted Polymer

    Institute of Scientific and Technical Information of China (English)

    CHEN Fei-fei

    2015-01-01

    Objective:To explore the application of molecular imprinting technique in the separation and detection of nimodipine. Methods:Methacrylic acid as functional monomer, pentaerythritol triacrylate as cross-linking agent were used to prepare molecularly imprinted polymer (MIP) with the feature of specific recognition performance on imprinting molecule nimodipine under condition of template molecule nimodipine. The preparation conditions, recognition performance of MIP on nimodipine, different proportions of template molecule and functional monomer, the selectivity to other substrate, and the relationship between adsorption quantity (Q) and time were observed. Results: MIP was prepared successfully by nimodipine as template and pentaerythritol triacrylate as cross-linking agent, with the feature of speciifc recognition performance on nimodipine. The static adsorption distribution coefifcient (KD) was 0.2264. The equation of Q and the concentration of substrate of template MIP was y = -0.21x+0.2204. Combining capacity of template molecule at the same concentration enhanced with the increasing proportion of functional monomer. Conclusion:Nimodipine MIP based on molecular imprinting technique may become a new approach to chiral separation for nimodipine.

  9. Molecular imprinted polymers for separation science: a review of reviews.

    Science.gov (United States)

    Cheong, Won Jo; Yang, Song Hee; Ali, Faiz

    2013-02-01

    Molecular imprinted polymer is an artificial receptor made by imprinting molecules of a template in a polymer matrix followed by removing the template molecules via thorough washing to give the permanent template grooves. They show favored affinity to the template molecule compared to other molecules, and this property is the basic driving force for such diverse application of this techniques. Such techniques have been increasingly employed in a wide scope of applications such as chromatography, sample pretreatment, purification, catalysts, sensors, and drug delivery, etc., mostly in bioanalytical areas. A major part of them is related to development of new stationary phases and their application in chromatography and sample pretreatment. Embodiments of molecular imprinted polymer materials have been carried out in a variety of forms such as irregularly ground particles, regular spherical particles, nanoparticles, monoliths in a stainless steel or capillary column, open tubular layers in capillaries, surface attached thin layers, membranes, and composites, etc. There have been numerous review articles on molecular imprinted polymer issues. In this special review, the reviews in recent ca. 10 years will be categorized into several subgroups according to specified topics in separation science, and each review in each subgroup will be introduced in the order of date with brief summaries and comments on new developments and different scopes of prospects. Brief summaries of each categories and conclusive future perspectives are also given.

  10. Preparation and Property Recognition of Nimodipine Molecularly Imprinted Polymer

    Directory of Open Access Journals (Sweden)

    Fei-fei CHEN

    2015-09-01

    Full Text Available Objective: To explore the application of molecular imprinting technique in the separation and detection of nimodipine. Methods: Methacrylic acid as functional monomer, pentaerythritol triacrylate as cross-linking agent were used to prepare molecularly imprinted polymer (MIP with the feature of specific recognition performance on imprinting molecule nimodipine under condition of template molecule nimodipine. The preparation conditions, recognition performance of MIP on nimodipine, different proportions of template molecule and functional monomer, the selectivity to other substrate, and the relationship between adsorption quantity (Q and time were observed. Results: MIP was prepared successfully bynimodipine as template and pentaerythritol triacrylate as cross-linking agent, with the feature of specific recognition performance on nimodipine. The static adsorption distribution coefficient (KD was 0.2264. The equation of Q and the concentration of substrate of template MIP was y = -0.21x+0.2204. Combining capacity of template molecule at the same concentration enhanced with the increasing proportion of functional monomer.Conclusion: Nimodipine MIP based on molecular imprinting technique may become a new approach to chiral separation for nimodipine.

  11. Molecularly imprinted polymers for histamine recognition in aqueous environment.

    Science.gov (United States)

    Trikka, Foteini A; Yoshimatsu, Keiichi; Ye, Lei; Kyriakidis, Dimitrios A

    2012-11-01

    Molecularly imprinted polymers (MIP) for histamine using methacrylic acid were developed and recognition mechanisms were thoroughly characterized for the first time in this study. The binding affinity of imprinted polymer with structurally related compounds was studied in organic and aqueous media, at various conditions. In organic media, MIP was found to bind histamine two and six times more than ranitidine and fluoxetine, respectively, whereas higher selectivity was observed in the case of dimentidene or disodium cromoglycate. The specific binding sites of MIP recognized histamine over L-histidine in aqueous conditions, while higher affinity for histamine compared to ranitidine, disodium cromoglycate, putrescine and to a putrescine analogue was observed. A combination of NMR and UV spectroscopy analyses for investigation of imprinting and recognition properties revealed that strong specific interactions between the functional monomer and histamine in the prepolymerization and in the aqueous solutions were probably responsible for histamine recognition. The preparation of histamine MIPs and elucidation of imprinting and recognition mechanism may serve as useful insight for future application of MIPs.

  12. Prenatal imprinting by environmental toxicants: really an important issue?

    Directory of Open Access Journals (Sweden)

    Karl Ernst v. Mühlendahl

    2015-06-01

    Full Text Available Prenatal imprinting of sexual behaviour and of other traits by environmental toxicants has been one important topic in the ongoing discussions in environmental medicine. This review of the literature shows that, so far, concrete data are sparse and, in part, contradictory.

  13. SEXUAL IMPRINTING IN THE COLLARED DOVE (STREPTOPELIA-DECAOCTO)

    NARCIS (Netherlands)

    TENCATE, C; HILBERS, J; HALL, M

    1992-01-01

    Although the occurrence of sexual imprinting has been demonstrated for doves, it is less well known how strong this effect is and which factors contribute to it. Therefore we examined whether cross-fostering collared doves (Streptopelia decaocto) to white ring doves (Streptopelia risoria) affected l

  14. In Celebration: The National Union Catalog, Pre-1956 Imprints.

    Science.gov (United States)

    Cole, John Y., Ed.

    This document contains the principal papers from a 1981 symposium held to celebrate the completion of the 754-volume National Union Catalog, Pre-1956 Imprints. Papers by both those who use the National Union Catalog (NUC) and those who developed it are included. A brief preface describes the mission of the Center for the Book and the purpose of…

  15. Molecularly Imprinted Polymers and Highly Porous Materials in Sensing Applications

    Science.gov (United States)

    2007-04-01

    microspheres from dilute dispersion polymerization systems (52). MIPs have also been prepared as imprinted membranes by precipitation of linear...and 1200m2/g. Supercritical drying of polysilsesquioxanes results in the formation of aerogels . These very low density materials have been

  16. Imprints of the Quantum World in Classical Mechanics

    OpenAIRE

    de Gosson, Maurice A.; Hiley, Basil

    2010-01-01

    The imprints left by quantum mechanics in classical (Hamiltonian) mechanics are much more numerous than is usually believed. We show Using no physical hypotheses) that the Schroedinger equation for a nonrelativistic system of spinless particles is a classical equation which is equivalent to Hamilton's equations.

  17. Novel imprinting techniques for fabrication of multilevel flexible electronics

    NARCIS (Netherlands)

    Turkenburg, D.H.; Rendering, H.; Hovestad, A.; Stroeks, N.; Maury, P.; Moonen, P.; Huskens, J.; Barbu, I.; Meinders, E.R.

    2011-01-01

    We report a novel method to selectively deposit materials from solution into imprinted micro-capillaries. Dewetting of the solvent just outside the capillaries is balanced to evaporation inside the capillaries. In this way conductive u-wires can be self-assembled and self-aligned on flexible

  18. Shape recognition of microbial cells by colloidal cell imprints

    NARCIS (Netherlands)

    Borovicka, J.; Stoyanov, S.D.; Paunov, V.N.

    2013-01-01

    We have engineered a class of colloids which can recognize the shape and size of targeted microbial cells and selectively bind to their surfaces. These imprinted colloid particles, which we called "colloid antibodies", were fabricated by partial fragmentation of silica shells obtained by templating

  19. Roll-to-roll UV imprint lithography for flexible electronics

    NARCIS (Netherlands)

    Maury, P.; Turkenburg, D.H.; Stroeks, N.; Giesen, P.; Barbu, I.; Meinders, E.R.; Bremen, A. van; Iosad, N.; Werf, R. van der; Onvlee, H.

    2011-01-01

    We propose a roll-to-roll UV imprint lithography tool as a way to pattern flexible PET foil with µm-resolution. As a way to overcome dimensional instability of the foil and its effect on overlay, a self-align approach was investigated, that permits to make several layers in a single lithography step

  20. Factors associated with aberrant imprint methylation and oligozoospermia

    Science.gov (United States)

    Kobayashi, Norio; Miyauchi, Naoko; Tatsuta, Nozomi; Kitamura, Akane; Okae, Hiroaki; Hiura, Hitoshi; Sato, Akiko; Utsunomiya, Takafumi; Yaegashi, Nobuo; Nakai, Kunihiko; Arima, Takahiro

    2017-01-01

    Disturbingly, the number of patients with oligozoospermia (low sperm count) has been gradually increasing in industrialized countries. Epigenetic alterations are believed to be involved in this condition. Recent studies have clarified that intrinsic and extrinsic factors can induce epigenetic transgenerational phenotypes through apparent reprogramming of the male germ line. Here we examined DNA methylation levels of 22 human imprinted loci in a total of 221 purified sperm samples from infertile couples and found methylation alterations in 24.8% of the patients. Structural equation model suggested that the cause of imprint methylation errors in sperm might have been environmental factors. More specifically, aberrant methylation and a particular lifestyle (current smoking, excess consumption of carbonated drinks) were associated with severe oligozoospermia, while aging probably affected this pathology indirectly through the accumulation of PCB in the patients. Next we examined the pregnancy outcomes for patients when the sperm had abnormal imprint methylation. The live-birth rate decreased and the miscarriage rate increased with the methylation errors. Our research will be useful for the prevention of methylation errors in sperm from infertile men, and sperm with normal imprint methylation might increase the safety of assisted reproduction technology (ART) by reducing methylation-induced diseases of children conceived via ART. PMID:28186187

  1. Extrusion Roller Imprinting with a Variotherm Belt Mold

    Directory of Open Access Journals (Sweden)

    Raymond Frenkel

    2014-12-01

    Full Text Available Although many precision fabrication techniques have demonstrated the ability to produce microstructures and micro-devices with sub 100 nm accuracy, we are yet to see a scalable manufacturing process for large-area production. One promising solution to scalable micro- and nanofabrication is thermal roller imprinting. However, existing investigations on thermal roller imprinting revealed poor pattern transfer fidelity, especially for high aspect ratio features. The standard roller imprinting process suffers from the lack of an effective holding and cooling stage so that the adverse effects from the viscoelastic nature of polymers are not managed. To rectify this problem and further improve the production rate, a new extrusion roller imprinting process with a variotherm belt mold is designed, and its prototype was established at a laboratory scale. The process testing results demonstrate that a 30 μm sawtooth pattern can be faithfully transferred to extruded polyethylene film at take-up speeds higher than 10 m/min. The results are promising in that microfeatures or even nanofeatures may be successfully replicated by a robust and scalable industrial process suitable for large-area, continuous production.

  2. Genome-wide DNA methylation analysis of transient neonatal diabetes type 1 patients with mutations in ZFP57

    DEFF Research Database (Denmark)

    Bak, Mads; Boonen, Susanne E; Dahl, Christina;

    2016-01-01

    involved in establishment and maintenance of methylation of imprinted loci. Our objective was to investigate whether additional regions are aberrantly methylated in ZFP57 mutation carriers. METHODS: Genome-wide DNA methylation analysis was performed on four individuals with homozygous or compound...... and HYMAI. A subset of patients with maternal hypomethylation at PLAGL1 have hypomethylation at additional imprinted loci throughout the genome, including GRB10, ZIM2 (PEG3), MEST (PEG1), KCNQ1OT1 and NESPAS (GNAS-AS1). About half of the TNDM1 patients carry mutations in ZFP57, a transcription factor...

  3. The systemic imprint of growth and its uses in ecological (metagenomics.

    Directory of Open Access Journals (Sweden)

    Sara Vieira-Silva

    2010-01-01

    Full Text Available Microbial minimal generation times range from a few minutes to several weeks. They are evolutionarily determined by variables such as environment stability, nutrient availability, and community diversity. Selection for fast growth adaptively imprints genomes, resulting in gene amplification, adapted chromosomal organization, and biased codon usage. We found that these growth-related traits in 214 species of bacteria and archaea are highly correlated, suggesting they all result from growth optimization. While modeling their association with maximal growth rates in view of synthetic biology applications, we observed that codon usage biases are better correlates of growth rates than any other trait, including rRNA copy number. Systematic deviations to our model reveal two distinct evolutionary processes. First, genome organization shows more evolutionary inertia than growth rates. This results in over-representation of growth-related traits in fast degrading genomes. Second, selection for these traits depends on optimal growth temperature: for similar generation times purifying selection is stronger in psychrophiles, intermediate in mesophiles, and lower in thermophiles. Using this information, we created a predictor of maximal growth rate adapted to small genome fragments. We applied it to three metagenomic environmental samples to show that a transiently rich environment, as the human gut, selects for fast-growers, that a toxic environment, as the acid mine biofilm, selects for low growth rates, whereas a diverse environment, like the soil, shows all ranges of growth rates. We also demonstrate that microbial colonizers of babies gut grow faster than stabilized human adults gut communities. In conclusion, we show that one can predict maximal growth rates from sequence data alone, and we propose that such information can be used to facilitate the manipulation of generation times. Our predictor allows inferring growth rates in the vast majority of

  4. PRC2 represses transcribed genes on the imprinted inactive X chromosome in mice.

    Science.gov (United States)

    Maclary, Emily; Hinten, Michael; Harris, Clair; Sethuraman, Shriya; Gayen, Srimonta; Kalantry, Sundeep

    2017-05-03

    Polycomb repressive complex 2 (PRC2) catalyzes histone H3K27me3, which marks many transcriptionally silent genes throughout the mammalian genome. Although H3K27me3 is associated with silenced gene expression broadly, it remains unclear why some but not other PRC2 target genes require PRC2 and H3K27me3 for silencing. Here we define the transcriptional and chromatin features that predict which PRC2 target genes require PRC2/H3K27me3 for silencing by interrogating imprinted mouse X-chromosome inactivation. H3K27me3 is enriched at promoters of silenced genes across the inactive X chromosome. To abrogate PRC2 function, we delete the core PRC2 protein EED in F1 hybrid trophoblast stem cells (TSCs), which undergo imprinted inactivation of the paternally inherited X chromosome. Eed (-/-) TSCs lack H3K27me3 and Xist lncRNA enrichment on the inactive X chromosome. Despite the absence of H3K27me3 and Xist RNA, only a subset of the inactivated X-linked genes is derepressed in Eed (-/-) TSCs. Unexpectedly, in wild-type (WT) TSCs these genes are transcribed and are enriched for active chromatin hallmarks on the inactive-X, including RNA PolII, H3K27ac, and H3K36me3, but not the bivalent mark H3K4me2. By contrast, PRC2 targets that remain repressed in Eed (-/-) TSCs are depleted for active chromatin characteristics in WT TSCs. A comparative analysis of transcriptional and chromatin features of inactive X-linked genes in WT and Eed (-/-) TSCs suggests that PRC2 acts as a brake to prevent induction of transcribed genes on the inactive X chromosome, a mode of PRC2 function that may apply broadly.

  5. Rational preparation of dibenzothiophene-imprinted polymers by surface imprinting technique combined with atom transfer radical polymerization

    Science.gov (United States)

    Yang, Wenming; Liu, Lukuan; Zhou, Zhiping; Liu, Hong; Xie, Binze; Xu, Wanzhen

    2013-10-01

    A computational simulation method is introduced to simulate the dibenzothiophene-monomer pre-assembly system of molecular imprinted polymers. The interaction type and intensity between dibenzothiophene and monomer are discussed from the binding energy and spatial position distribution. The simulation and analysis results indicate that the amount of the function monomer is not the more the better in preparing molecular imprinted polymers. Based on the above results, a novel dibenzothiophene-imprinted polymers with the favorable specific adsorption effect was prepared by surface imprinting technique combined with atom transfer radical polymerization. This combined technologies are used for preparing a desulfurization adsorbent for the first time. Various measures were selected to characterize the structure and morphology of the prepared adsorbent. The characterization results show that the adsorbent has suitable features for further adsorption process. A series of static adsorption experiments were conducted to analyze its adsorption performance. The adsorption process follows Elovich model by the kinetic analysis and Sips equation by the isothermal analysis. The approach we described will provide another opportunity in the deep desulfurization field.

  6. Fingerprint-imprinted polymer: rational selection of peptide epitope templates for the determination of proteins by molecularly imprinted polymers.

    Science.gov (United States)

    Bossi, Alessandra M; Sharma, Piyush S; Montana, Luca; Zoccatelli, Gianni; Laub, Orgad; Levi, Raphael

    2012-05-01

    The pool of peptides composing a protein allows for its distinctive identification in a process named fingerprint (FP) analysis. Here, the FP concept is used to develop a method for the rational preparation of molecularly imprinted polymers (MIPs) for protein recognition. The fingerprint imprinting (FIP) is based on the following: (1) the in silico cleavage of the protein sequence of interest with specific agents; (2) the screening of all the peptide sequences generated against the UniProtKB database in order to allow for the rational selection of distinctive and unique peptides (named as epitopes) of the target protein; (3) the selected epitopes are synthesized and used as templates for the molecular imprinting process. To prove the principle, NT-proBNP, a marker of the risk of cardiovascular events, was chosen as an example. The in silico analysis of the NT-proBNP sequence allowed us to individuate the peptide candidates, which were next used as templates for the preparation of NT-pro-BNP-specific FIPs and tested for their ability to bind the NT-proBNP peptides in complex samples. Results indicated an imprinting factor, IF, of ~10, a binding capacity of 0.5-2 mg/g, and the ability to rebind 40% of the template in a complex sample, composed of the whole digests of NT-proBNP.

  7. A sensitive and selective molecularly imprinted sensor combined with magnetic molecularly imprinted solid phase extraction for determination of dibutyl phthalate.

    Science.gov (United States)

    Zhang, Zhaohui; Luo, Lijuan; Cai, Rong; Chen, Hongjun

    2013-11-15

    A highly sensitive and selective molecularly imprinted (MIP) sensor combined with magnetic molecularly imprinted solid phase extraction (MMISPE) was developed for the determination of dibutyl phthalate (DBP) in complex matrixes. The magnetic molecularly imprinted polymer (MMIP) was synthesized as solid phase extraction (SPE) sorbet to extract DBP from complex matrixes and as sensing element to improve the selectivity of the imprinted sensor. The morphologies of MMIP and MIP-sensor were characterized by using scanning electron microscope (SEM) and transmission electron microscopy (TEM). The electrochemical performances of MIP-sensor were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The conditions of preconcentration, elution and electrochemical determination were studied in detail. Under the optimized experimental conditions, the response currents of the MIP-sensor exhibited a linear relationship towards DBP concentrations ranging from 1.0 × 10(-8)g/L to 1.0 × 10(-3)g/L. The limit of detection of the MMIP-sensor coupled with the MMISPE was calculated as 0.052 ng/L. The MMIP-sensor coupled with the MMISPE was applied to detect DBP in complex samples successfully.

  8. The effects of social rearing on preferences formed during filial imprinting and their neural correlates.

    Science.gov (United States)

    Town, Stephen Michael

    2011-08-01

    Filial imprinting was originally proposed to be an irreversible process by which a young animal forms a preference for an object experienced early in life. The present study examined the effects of experience after imprinting on the stability of preferences of domestic chicks (Gallus gallus domesticus) for an imprinting stimulus by rearing imprinted chicks socially or in isolation. Chicks reared socially or in isolation retained preferences for the imprinting stimulus; however, social rearing weakened the strength of preferences. The responses of neurons within the intermediate and medial mesopallium--a forebrain region necessary for imprinting were also recorded in socially reared and isolated chicks when presented with the visual component of the imprinting stimulus and novel object. Consistent with existing findings, neurons recorded from isolated chicks responded more strongly to the imprinting stimulus than novel object. However, social rearing diminished the disparity between responses to stimuli such that neurons recorded from socially reared chicks responded similarly to the imprinting stimulus and novel object. These findings suggest that social rearing may impair the retention of preferences formed during imprinting through mechanisms involving the IMM.

  9. Preparation and adsorption behaviors of Cu(Ⅱ) ion-imprinted polymers

    Institute of Scientific and Technical Information of China (English)

    ZHONG Shi-an; YUAN Zhou-lv; QIAO Rong; LI Wei

    2008-01-01

    Imprinted polymers were prepared for selective removal of Cu(II) ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid (MAA), acrylamide (AA) and N,N'-methylenebisacrylamide (MBAA) respectively as the functional monomers, ethleneglycoldimethacrylate (EGDMA) as the cross-linking agent, 2,2'-azobisisobutyronitrile (AIBN) as the initiator and Cu (II) ion as the imprint ion. The template Cu (II) ion was removed from the polymer by leaching with a liquid of a 1:1 volumetric ratio of HCl to ethylenediaminetetraacetic acid (EDTA). The capacity and selectivity of Cu(II) ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu(II) ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu(II) adsorption than non-imprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu (II) ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction (SPE).

  10. Imprinting mutations in Angelman syndrome detected by Southern blotting using a probe containing exon {alpha} of SNRPN

    Energy Technology Data Exchange (ETDEWEB)

    Beuten, J.; Sutcliffe, J.S.; Nakao, M. [Baylor College of Medicine, Houston, TX (United States)] [and others

    1994-09-01

    Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are associated with paternal and maternal deficiencies respectively, of gene expression within human chromosome 15q11-q13, and are caused by deletion, uniparental disomy (UPD), or other mutations. The SNRPN gene maps in this region, is paternally expressed, and is a candidate gene for PWS. Southern blotting using methylation-sensitive enzymes and a genomic DNA probe from the CpG island containing exon {alpha} of the SNRPN gene reveals methylation specific for the maternal allele. In cases of the usual deletions or UPD, the probe detects absence of an unmethylated allele in PWS and absence of a methylated allele in AS. We have analyzed 21 nondeletion/nonUPD AS patients with this probe and found evidence for an imprinting mutation (absence of a methylated allele) in 3 patients. Southern blotting with methylation-sensitive enzymes using the exon {alpha} probe, like use of the PW71 probe, should detect abnormalities in all known PWS cases and in 3 of the 4 forms of AS: deletion, UPD and imprinting mutations. This analysis provides a valuable diagnostic approach for PWS and AS. In efforts to localize the imprinting mutations in AS, one patient was found with failure to inherit a dinucleotide repeat polymorphism near probe 189-1 (D15S13). Analysis of this locus in AS families and CEPH families demonstrates a polymorphism that impairs amplification and a different polymorphism involving absence of hybridization to the 189-1 probe. The functional significance, if any, of deletion of the 189-1 region is unclear.

  11. Imprinted chromosomal domains revealed by allele-specific replication timing of the GABRB3 and GABRA5 genes

    Energy Technology Data Exchange (ETDEWEB)

    LaSalle, J.; Flint, A.; Lalande, M. [Harvard Medical School, Boston, MA (United States)] [and others

    1994-09-01

    The GABRB3 and GABRA5 genes are organized as a cluster in chromosome 15q11-q13. The genes are separated by around 100 kb and arranged in opposite transcriptional orientations. The GABA{sub A} receptor cluster lies near the Angelman and Prader-Willi loci and displays asynchronous DNA replication, suggesting that this region is subject to parental imprinting. In order to further study the association between DNA replication and imprinting, allele-specific replication was assayed by fluorescence in situ hybridization with {lambda}-phage probes from the GABRB3/A5 region and a D15Z1 satellite probe to identify the parental origin of each chromosome. The replication kinetics of each allele was determined by using a flow sorter to fractionate mitogen-stimulated lymphocytes on the basis of cell cycle progression prior to FISH analysis. These kinetic studies reveal a 50-150 kb chromosomal domain extending from the middle of the GABRB3/A5 intergenic region into the GABRA5 5{prime}-UTR which displays maternal replication in early S with paternal replication delayed until the end of S. In contrast, genomic regions on either side of this maternal early replication domain exhibit the opposite pattern with paternal before maternal replication and both alleles replicating in the latter half of S. These results indicate that the GABRB3/A5 region is divided into domains in which replication timing is determined by parental origin. In addition to a loss of asynchronous replication, organization into replication timing domains is also lost in lymphocytes from maternal and paternal uniparental disomy 15 patients suggesting that a chromosome contribution from both parents is required for the establishment of the imprinted replication domains.

  12. Molecularly imprinted polymers prepared using protein-conjugated cleavable monomers followed by site-specific post-imprinting introduction of fluorescent reporter molecules.

    Science.gov (United States)

    Suga, Yusuke; Sunayama, Hirobumi; Ooya, Tooru; Takeuchi, Toshifumi

    2013-10-01

    Molecularly imprinted polymers were prepared using a protein-conjugated disulfide cleavable monomer. After removing the protein by disulfide reduction, a thiol-reactive fluorophore was introduced into the thiol residue located only inside the imprinted cavity, resulting in specific transduction of the binding events into fluorescence spectral change.

  13. DNA Methylation Profiling of Uniparental Disomy Subjects Provides a Map of Parental Epigenetic Bias in the Human Genome.

    Science.gov (United States)

    Joshi, Ricky S; Garg, Paras; Zaitlen, Noah; Lappalainen, Tuuli; Watson, Corey T; Azam, Nidha; Ho, Daniel; Li, Xin; Antonarakis, Stylianos E; Brunner, Han G; Buiting, Karin; Cheung, Sau Wai; Coffee, Bradford; Eggermann, Thomas; Francis, David; Geraedts, Joep P; Gimelli, Giorgio; Jacobson, Samuel G; Le Caignec, Cedric; de Leeuw, Nicole; Liehr, Thomas; Mackay, Deborah J; Montgomery, Stephen B; Pagnamenta, Alistair T; Papenhausen, Peter; Robinson, David O; Ruivenkamp, Claudia; Schwartz, Charles; Steiner, Bernhard; Stevenson, David A; Surti, Urvashi; Wassink, Thomas; Sharp, Andrew J

    2016-09-01

    Genomic imprinting is a mechanism in which gene expression varies depending on parental origin. Imprinting occurs through differential epigenetic marks on the two parental alleles, with most imprinted loci marked by the presence of differentially methylated regions (DMRs). To identify sites of parental epigenetic bias, here we have profiled DNA methylation patterns in a cohort of 57 individuals with uniparental disomy (UPD) for 19 different chromosomes, defining imprinted DMRs as sites where the maternal and paternal methylation levels diverge significantly from the biparental mean. Using this approach we identified 77 DMRs, including nearly all those described in previous studies, in addition to 34 DMRs not previously reported. These include a DMR at TUBGCP5 within the recurrent 15q11.2 microdeletion region, suggesting potential parent-of-origin effects associated with this genomic disorder. We also observed a modest parental bias in DNA methylation levels at every CpG analyzed across ∼1.9 Mb of the 15q11-q13 Prader-Willi/Angelman syndrome region, demonstrating that the influence of imprinting is not limited to individual regulatory elements such as CpG islands, but can extend across entire chromosomal domains. Using RNA-seq data, we detected signatures consistent with imprinted expression associated with nine novel DMRs. Finally, using a population sample of 4,004 blood methylomes, we define patterns of epigenetic variation at DMRs, identifying rare individuals with global gain or loss of methylation across multiple imprinted loci. Our data provide a detailed map of parental epigenetic bias in the human genome, providing insights into potential parent-of-origin effects.

  14. High volume nanoscale roll-based imprinting using jet and flash imprint lithography

    Science.gov (United States)

    Ahn, Se Hyun; Miller, Mike; Yang, Shuqiang; Ganapathisubramanian, Maha; Menezes, Marlon; Singh, Vik; Choi, Jin; Xu, Frank; LaBrake, Dwayne; Resnick, Douglas J.; Sreenivasan, S. V.

    2013-09-01

    Extremely large-area roll-to-roll (R2R) manufacturing on flexible substrates is ubiquitous for applications such as paper and plastic processing. It combines the benefits of high speed and inexpensive substrates to deliver a commodity product at low cost. The challenge is to extend this approach to the realm of nanopatterning and realize similar benefits. In order to achieve low-cost nanopatterning, it is imperative to move toward high-speed imprinting, less complex tools, near zero waste of consumables, and low-cost substrates. We have developed a roll-based J-FIL process and applied it to a technology demonstrator tool, the LithoFlex 100, to fabricate large-area flexible bilayer wire-grid polarizers (WGPs) and high-performance WGPs on rigid glass substrates. Extinction ratios of better than 10,000 are obtained for the glass-based WGPs. Two simulation packages are also employed to understand the effects of pitch, aluminum thickness, and pattern defectivity on the optical performance of the WGP devices. It is determined that the WGPs can be influenced by both clear and opaque defects in the gratings; however, the defect densities are relaxed relative to the requirements of a high-density semiconductor device.

  15. Enhanced adsorption of atrazine from aqueous solution by molecularly imprinted TiO2 film

    Science.gov (United States)

    Zhang, Chunjing; Yan, Jinlong; Zhang, Chunxiao; Yang, Zhengpeng

    2012-07-01

    TiO2 film imprinted by atrazine molecule at the surface of quartz crystal was prepared using molecular imprinting and surface sol-gel process. The molecularly imprinted TiO2 film was characterized by scanning electron microscopy and cyclic voltammetry, and the atrazine adsorption was investigated by quartz crystal microbalance (QCM) technique. In comparison with non-imprinted TiO2 film, the molecularly imprinted TiO2 film exhibits high selectivity for atrazine, better reversibility and a much higher adsorption capacity for the target molecule, the adsorption equilibrium constant estimated from the in situ frequency measurement is about 6.7 × 104 M-1, which is thirteen times higher than that obtained on non-imprinted TiO2 film.

  16. Recognizing Amino Acid Chirality with Surface-Imprinted Polymers Prepared in W/O Emulsions

    Directory of Open Access Journals (Sweden)

    Min Jae Shin

    2013-01-01

    Full Text Available A molecularly imprinted polymer was prepared by a surface molecular imprinting technique in water-in-oil (W/O emulsion. In this technique, the solid polymer, which is molecularly imprinted at the internal cavity surface, is prepared by polymerizing W/O emulsions consisting of a water-soluble imprinted molecule, a functional host molecule, an emulsion stabilizer, and a crosslinking agent. Dioleoyl phosphate was used as an emulsion stabilizer, and this compound also acted as a monomer and a host functional group in the imprinted cavity. Divinylbenzene was used as a crosslinker. Tryptophan methyl ester and phenylalanine methyl ester were used as the target template materials. These imprinted polymers exhibited enantiomeric selectivity in absorption experiments, and the maximum separation factor was 1.58. The enantiomeric selectivity with tryptophan methyl ester was higher than that with phenylalanine methyl ester.

  17. Microcontact imprinting of algae for biofuel systems: the effects of the polymer concentration.

    Science.gov (United States)

    Lee, Mei-Hwa; Thomas, James L; Lai, Ming-Yuan; Shih, Ching-Ping; Lin, Hung-Yin

    2014-11-25

    Microcontact imprinting of cells often involves the deposition of a polymer solution onto a monolayer cell stamp, followed by solvent evaporation. Thus, the concentration of the polymer may play an important role in the final morphology and efficacy of the imprinted film. In this work, various concentrations of poly(ethylene-co-vinyl alcohol) (EVAL) were dissolved in dimethyl sulfoxide (DMSO) for the microcontact imprinting of algae on an electrode. Scanning electron microscopy and fluorescence spectrometry were used to characterize the surface morphology and recognition capacity of algae to the algae-imprinted cavities. The readsorption of algae onto algae-imprinted EVAL thin films was quantified to obtain the EVAL concentration that maximized algal binding. Finally, the power and current density of an algal biofuel cell with the algae-imprinted EVAL-coated electrode were measured and found to be approximately double those of such a cell with a Pt/indium tin oxide (ITO)/poly(ethylene terephthalate) (PET) electrode.

  18. Characterization of the imprinting and expression patterns of ZAG2 in maize endosperm and embryo

    Directory of Open Access Journals (Sweden)

    Chaoxian Liu

    2015-02-01

    Full Text Available ZAG2 has been identified as a maternally expressed imprinted gene in maize endosperm. Our study revealed that paternally inherited ZAG2 alleles were imprinted in maize endosperm and embryo at 14 days after pollination (DAP, and consistently imprinted in endosperm at 10, 12, 16, 18, 20, 22, 24, 26, and 28 DAP in reciprocal crosses between B73 and Mo17. ZAG2 alleles were also imprinted in reciprocal crosses between Zheng 58 and Chang 7-2 and between Huang C and 178. ZAG2 alleles exhibited differential imprinting in hybrids of 178 × Huang C and B73 × Mo17, while in other hybrids ZAG2 alleles exhibited binary imprinting. The tissue-specific expression pattern of ZAG2 showed that ZAG2 was expressed at a high level in immature ears, suggesting that ZAG2 plays important roles in not only kernel but ear development.

  19. Rasgrf1 Imprinting Is Regulated by a CTCF-Dependent Methylation-Sensitive Enhancer Blocker

    Science.gov (United States)

    Yoon, Bongjune; Herman, Herry; Hu, Benjamin; Park, Yoon Jung; Lindroth, Anders; Bell, Adam; West, Adam G.; Chang, Yanjie; Stablewski, Aimee; Piel, Jessica C.; Loukinov, Dmitri I.; Lobanenkov, Victor V.; Soloway, Paul D.

    2005-01-01

    Imprinted methylation of the paternal Rasgrf1 allele in mice occurs at a differentially methylated domain (DMD) 30 kbp 5′ of the promoter. A repeated sequence 3′ of the DMD regulates imprinted methylation, which is required for imprinted expression. Here we identify the mechanism by which methylation controls imprinting. The DMD is an enhancer blocker that binds CTCF in a methylation-sensitive manner. CTCF bound to the unmethylated maternal allele silences expression. CTCF binding to the paternal allele is prevented by repeat-mediated methylation, allowing expression. Optimal in vitro enhancer-blocking activity requires CTCF binding sites. The enhancer blocker can be bypassed in vivo and imprinting abolished by placing an extra enhancer proximal to the promoter. Together, the repeats and the DMD constitute a binary switch that regulates Rasgrf1 imprinting. PMID:16314537

  20. Epigenetic Consequences of Artificial Reproductive Technologies to the Bovine Imprinted Genes SNRPN, H19/IGF2 and IGF2R

    Directory of Open Access Journals (Sweden)

    Lawrence C. Smith

    2015-02-01

    Full Text Available Animal breeders have made widespread use of assisted reproductive technologies to accelerate genetic improvement programs aimed at obtaining more, better and cheaper food products. Selection approaches have traditionally focused on Mendel’s laws of inheritance using parental phenotypic characteristics and quantitative genetics approaches to choose the best parents for the next generation, regardless of their gender. However, apart from contributing DNA sequence variants, male and female gametes carry parental-specific epigenetic marks that play key roles during pre- and post-natal development and growth of the offspring. We herein review the epigenetic anomalies that are associated with artificial reproductive technologies in current use in animal breeding programs. For instance, we demonstrate that bovine embryos and foetuses derived by in vitro culture and somatic cell nuclear transfer show epigenetic anomalies in the differentially methylated regions controlling the expression of some imprinted genes. Although these genomic imprinting errors are undetected in the somatic tissues after birth, further research is warranted to examine potential germ cell transmission of epimutations and the potential risks of reproducing cattle using artificial reproductive technologies.

  1. Preliminary evidence of a neurophysiological basis for individual discrimination in filial imprinting.

    Science.gov (United States)

    Town, Stephen Michael

    2011-12-01

    Filial imprinting involves a predisposition for biologically important stimuli and a learning process directing preferences towards a particular stimulus. Learning underlies discrimination between imprinted and unfamiliar individuals and depends upon the IMM (intermediate and medial mesopallium). Here, IMM neurons responded differentially to familiar and unfamiliar conspecifics following socialization and the neurophysiological effects of social experience differed between hemispheres. Such findings may provide a neurophysiological basis for individual discrimination in imprinting. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Ion imprinted polymers: fundamentals, preparation strategies and applications in analytical chemistry

    OpenAIRE

    Luiz Diego Marestoni; Maria Del Pilar Taboada Sotomayor; Mariana Gava Segatelli; Lucas Rossi Sartori; César Ricardo Teixeira Tarley

    2013-01-01

    Chemical imprinting technology has been widely used as a valuable tool in selective recognition of a given target analyte (molecule or metal ion), yielding a notable advance in the development of new analytical protocols. Since their discovery, molecularly imprinted polymers (MIPs) have been extensively studied with excellent reviews published. However, studies involving ion imprinted polymers (IIPs), in which metal ions are recognized in the presence of closely related inorganic ions, remain...

  3. Removal of Toxic Mercury from Petroleum Oil by Newly Synthesized Molecularly-Imprinted Polymer

    OpenAIRE

    Nor Ain Shahera Khairi; Nor Azah Yusof; Abdul Halim Abdullah; Faruq Mohammad

    2015-01-01

    In recent years, molecularly-imprinted polymers (MIPs) have attracted the attention of several researchers due to their capability for molecular recognition, easiness of preparation, stability and cost-effective production. By taking advantage of these facts, Hg(II) imprinted and non-imprinted copolymers were prepared by polymerizing mercury nitrate stock solution (or without it) with methacrylic acid (MAA), 2-hydroxyl ethyl methacrylate (HEMA), methanol and ethylene glycol dimethacrylate (E...

  4. Molecularly Imprinted Polymers: Thermodynamic and Kinetic Considerations on the Specific Sorption and Molecular Recognition

    OpenAIRE

    Kejun Tong; Wuke Li; Mingxia Zheng; Xing Huang; Songjun Li

    2008-01-01

    This article presents a work aiming at thermodynamically and kinetically interpreting the specific sorption and recognition by a molecularly imprinted polymer. Using Boc-L-Phe-OH as a template, the imprinted material was prepared. The result indicates that the prepared polymer can well discriminate the imprint species from its analogue (Boc-D-Phe-OH), so as to adsorb more for the former but less for the latter. Kinetic analysis indicates that this specific sorption, in nature, can be a result...

  5. Preparation and Chromatographic Application of β-Cyclodextrin Molecularly Imprinted Microspheres for Paeoniflorin

    OpenAIRE

    Wei Zhang; Bofeng Wei; Shoujiang Li; Yueming Wang; Shaoyan Wang

    2017-01-01

    The application of molecular imprinting technology in the separation and purification of active ingredients in natural products was widely reported, but remains a challenge. Enrichment and separation are especially limited. A surface imprinting technique was reported to synthesize molecularly imprinted microspheres (MIMs) in this article. With paeoniflorin (PF) as the template molecule, β-cyclodextrin (β-CD) and acrylamide (AA) as the functional monomers, and poly(glycidyl methacrylate, GMA) ...

  6. Preparation and Cyclic Voltammetry Characterization Of Cu-dipyridyl Imprinted Polymer

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Polymer capable of specific binding to Cu-dipyridyl complex was prepared by molecular imprinting technology.The binding specificity of the polymer to the template (Cu-dipyridyl complex) was investigated by cyclic voltametric scanning using the carbon paste electrode modified by polymer particles in phosphate buffer solution.Factors that influence rebinding of the imprinted polymer were explored.The result demonstrated that the cyclic voltammetry was an efficient approach to explore interactions between template and imprinted polymers.

  7. Molecular Imprinting Fibrous Membranes of Poly(acrylonitrile-co-acrylic acid) Prepared by Electrospinning

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Introduction Over the past few decades, molecular imprinting has been described as a technology for preparing "molecular doors" which can be matched to "template keys". It has been found to be a simple and effective approach to introduce specific recognition sites into synthetic polymers, namely, to create molecular imprinting polymers[1-4]. Remarkable features such as stability,ease of preparation and low cost, have made molecular imprinting polymers particularly attractive in chemical sensors, catalysis, drug delivery, and dedicated separations.

  8. Imprints of a Primordial Preferred Direction on the Microwave Background

    CERN Document Server

    Ackerman, L; Wise, M B; Ackerman, Lotty; Carroll, Sean M.; Wise, Mark B.

    2007-01-01

    Rotational invariance is a well-established feature of low-energy physics. Violations of this symmetry must be extremely small today, but could have been larger in earlier epochs. In this paper we examine the consequences of a small breaking of rotational invariance during the inflationary era when the primordial density fluctuations were generated. Assuming that a fixed-norm vector picked out a preferred direction during the inflationary era, we explore the imprint it would leave on the cosmic microwave background anisotropy, and provide explicit formulas for the expected amplitudes $$ of the spherical-harmonic coefficients. We suggest that it is natural to expect that the imprint on the primordial power spectrum of a preferred spatial direction is approximately scale-invariant, and examine a simple model in which this is true.

  9. Composite vascular repair grafts via micro-imprinting and electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuanyuan, E-mail: yuanyuan-liu@shu.edu.cn; Hu, Qingxi, E-mail: huqingxi@shu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China); Shanghai Key Laboratory of Intelligent Manufacturing and Robotics, Shanghai 200072 (China); Xiang, Ke, E-mail: xiangke@shu.edu.cn; Chen, Haiping, E-mail: 519673062@qq.com; Li, Yu, E-mail: liyu@hpu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China)

    2015-04-15

    Composite vascular grafts formed by micro-imprinting and electrospinning exhibited improved mechanical properties relative to those formed by electrospinning alone. The three-layered composite grafts mimic the three-layered structure of natural blood vessels. The middle layer is made by micro-imprinting poly-p-dioxanone (PPDO), while the inner and outer layers are electrospun mixtures of chitosan and polyvinyl alcohol. The graft morphology is characterized with scanning electron microscopy. For constant graft thicknesses, the PPDO increases the mechanical strength. Cells cultivated on the vascular grafts adhere and proliferate better because of the natural, biological chitosan in the inner and outer layers. Overall, the composite scaffolds could be good candidates for blood vessel repair.

  10. Magnetic molecularly imprinted polymer for aspirin recognition and controlled release

    Science.gov (United States)

    Kan, Xianwen; Geng, Zhirong; Zhao, Yao; Wang, Zhilin; Zhu, Jun-Jie

    2009-04-01

    Core-shell structural magnetic molecularly imprinted polymers (magnetic MIPs) with combined properties of molecular recognition and controlled release were prepared and characterized. Magnetic MIPs were synthesized by the co-polymerization of methacrylic acid (MAA) and trimethylolpropane trimethacrylate (TRIM) around aspirin (ASP) at the surface of double-bond-functionalized Fe3O4 nanoparticles in chloroform. The obtained spherical magnetic MIPs with diameters of about 500 nm had obvious superparamagnetism and could be separated quickly by an external magnetic field. Binding experiments were carried out to evaluate the properties of magnetic MIPs and magnetic non-molecularly imprinted polymers (magnetic NIPs). The results demonstrated that the magnetic MIPs had high adsorption capacity and selectivity to ASP. Moreover, release profiles and release rate of ASP from the ASP-loaded magnetic MIPs indicated that the magnetic MIPs also had potential applications in drug controlled release.

  11. Consequences of Morphology on Molecularly Imprinted Polymer-Ligand Recognition

    Directory of Open Access Journals (Sweden)

    Annika M. Rosengren

    2013-01-01

    Full Text Available The relationship between molecularly imprinted polymer (MIP morphology and template-rebinding over a series of warfarin-imprinted methacrylic acid co(ethylene dimethacrylate polymers has been explored. Detailed investigations of the nature of template recognition revealed that an optimal template binding was obtained with polymers possessing a narrow population of pores (~3–4 nm in the mesopore size range. Importantly, the warfarin-polymer rebinding analyses suggest strategies for regulating ligand binding capacity and specificity through variation of the degree of cross-linking, where polymers prepared with a lower degree of cross-linking afford higher capacity though non-specific in character. In contrast, the co-existence of specific and non-specific binding was found in conjunction with higher degrees of cross-linking and resultant meso- and macropore size distributions.

  12. Imprint reduction in rotating heavy ions beam energy deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bret, A., E-mail: antoineclaude.bret@uclm.es [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51, Cambridge, MA 02138 (United States); ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Piriz, A.R., E-mail: Roberto.Piriz@uclm.es [ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Tahir, N.A., E-mail: n.tahir@gsi.de [GSI Darmstadt, Plankstrasse 1, 64291 Darmstadt (Germany)

    2014-01-01

    The compression of a cylindrical target by a rotating heavy ions beam is contemplated in certain inertial fusion schemes or in heavy density matter experiments. Because the beam has its proper temporal profile, the energy deposition is asymmetric and leaves an imprint which can have important consequences for the rest of the process. In this paper, the Fourier components of the deposited ion density are computed exactly in terms of the beam temporal profile and its rotation frequency Ω. We show that for any beam profile of duration T, there exist an infinite number of values of ΩT canceling exactly any given harmonic. For the particular case of a parabolic profile, we find possible to cancel exactly the first harmonic and nearly cancel every other odd harmonics. In such case, the imprint amplitude is divided by 4 without any increase of Ω.

  13. Chemical Sensors Based on Molecularly Imprinted Sol-Gel Materials

    Directory of Open Access Journals (Sweden)

    Franz L. Dickert

    2010-03-01

    Full Text Available The sol-gel technique is earning the worldwide attention of researchers in the field of material science, due to its versatility in synthesizing inorganic ceramic materials at mild conditions. High purity, homogeneity, controlled porosity, stable temperature and nanoscale structuring are the most remarkable features offered by this method for generating highly sensitive and selective matrices to incorporate analyte molecules. The crafting of sol-gel sensors through molecular imprinting has put great influence on the development of innovative chemical sensors, which can be seen from the growing number of publications in this field. The review provides a brief overview of sol-gel sensor applications, and discusses the contribution of molecular imprinting in exploring the new world of sensors.

  14. Monocrotophos Molecularly Imprinted Microspheres Prepared by Precipitation Polymerization in Acetonitrile

    Institute of Scientific and Technical Information of China (English)

    Shoulei Yan; Zhixian Gao; Yanjun Fang; Yiyong Cheng

    2006-01-01

    Molecularly imprinted microspheres (MIP) for monocrotophos have been prepared by precipitation polymerization in acetonitrile (CAN) 60℃, 24 h, using methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA) and 2,2-azobisiobutyronitrile (AIBN) as functional monomer, cross-linker and initiator, respectively. The recognition mechanism was elucidated by UV-vis spectra and computer modeling. Equilibrium binding experiment was employed to investigate the rebinding properties, Scatchard analysis showed that specific binding sites formed in the imprinted microspheres, and there were two kinds of binding sites, one was high binding sites, the other was low binding sites. This microspheres can be useful affinity absorbent used for organophosphorus pesticides separation and purification in food and environmental analysis.

  15. The ISW imprints of voids and superclusters on the CMB

    Science.gov (United States)

    Hotchkiss, S.; Nadathur, S.; Gottlöber, S.; Iliev, I. T.; Knebe, A.; Watson, W. A.; Yepes, G.

    2016-10-01

    We examine the stacked integrated Sachs-Wolfe (ISW) imprints on the CMB along the lines of sight of voids and superclusters in galaxy surveys, using the Jubilee ISW simulation and mock luminous red galaxy (LRG) catalogues. We show that the expected signal in the concordance \\Lam CDM model is much smaller than the primary anisotropies arising at the last scattering surface and therefore any currently claimed detections of such an imprint cannot be caused by the ISW effect in \\Lam CDM. We look for the existence of such a signal in the Planck CMB using a catalogue of voids and superclusters from the Sloan Digital Sky Survey (SDSS), but find a result completely consistent with \\Lam CDM - i.e., a null detection.

  16. Chiral separation of racemic drugs using molecular imprinting

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Molecularly imprinted polymers (MIPs) of (S)-ketoprofen and (S)-naproxen are prepared using non-covalent imprinting in the presence of template molecules. The prepared MIPs are used as the chiral stationary phase to separate ramemic naproxen and ketoprofen. The results show that racemic naproxen and ketoprofen are efficiently resolved on MIPs. The effect of concentration of acetic acid in the mobile phase is studied, and the data are analyzed using the affinity chromatography model, and the close agreement is achieved between the simulated and experimental curves. The results suggest that the affinity chromatography mechanism controls the retention in this system. Moreover, the affinity chromatography equilibrium constants on (S)-naproxen and (S)-ketoprofen are estimated.

  17. Biotin-specific synthetic receptors prepared using molecular imprinting

    Energy Technology Data Exchange (ETDEWEB)

    Piletska, Elena; Piletsky, Sergey; Karim, Kal; Terpetschnig, Ewald; Turner, Anthony

    2004-02-16

    The composition of new molecularly imprinted polymers (MIPs) specific for biotin was optimised using molecular modelling software. Three functional monomers: methacrylic acid (MAA), 2-(trifluoromethyl)acrylic acid (TFAA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPSA), which demonstrated the highest binding scores with biotin, were tested on their ability to generate specific binding sites. The imprinted polymers were photografted to the surface of polystyrene microspheres in water. The affinity of the synthetic 'receptor' sites was evaluated in binding experiments using horseradish peroxidase-labelled biotin. Good correlation was found between the modelling results and the performance of the materials in the template re-binding study. The dissociation constants for all MIPs were 1.4-16.8 nM, which is sufficient for most analytical applications where biotin is used as a label.

  18. Magnetization dynamics of imprinted non-collinear spin textures

    Energy Technology Data Exchange (ETDEWEB)

    Streubel, Robert, E-mail: r.streubel@ifw-dresden.de; Kopte, Martin; Makarov, Denys, E-mail: d.makarov@ifw-dresden.de [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Fischer, Peter [Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, UC Santa Cruz, Santa Cruz, California 95064 (United States); Schmidt, Oliver G. [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, 09107 Chemnitz (Germany)

    2015-09-14

    We study the magnetization dynamics of non-collinear spin textures realized via imprint of the magnetic vortex state in soft permalloy into magnetically hard out-of-plane magnetized Co/Pd nanopatterned heterostructures. Tuning the interlayer exchange coupling between soft- and hard-magnetic subsystems provides means to tailor the magnetic state in the Co/Pd stack from being vortex- to donut-like with different core sizes. While the imprinted vortex spin texture leads to the dynamics similar to the one observed for vortices in permalloy disks, the donut-like state causes the appearance of two gyrofrequencies characteristic of the early and later stages of the magnetization dynamics. The dynamics are described using the Thiele equation supported by the full scale micromagnetic simulations by taking into account an enlarged core size of the donut states compared to magnetic vortices.

  19. Magnetic molecularly imprinted polymer for aspirin recognition and controlled release

    Energy Technology Data Exchange (ETDEWEB)

    Kan Xianwen; Geng Zhirong; Zhao Yao; Wang Zhilin; Zhu Junjie [State Key Laboratory of Coordination Chemistry, MOE Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)], E-mail: wangzl@nju.edu.cn, E-mail: jjzhu@nju.edu.cn

    2009-04-22

    Core-shell structural magnetic molecularly imprinted polymers (magnetic MIPs) with combined properties of molecular recognition and controlled release were prepared and characterized. Magnetic MIPs were synthesized by the co-polymerization of methacrylic acid (MAA) and trimethylolpropane trimethacrylate (TRIM) around aspirin (ASP) at the surface of double-bond-functionalized Fe{sub 3}O{sub 4} nanoparticles in chloroform. The obtained spherical magnetic MIPs with diameters of about 500 nm had obvious superparamagnetism and could be separated quickly by an external magnetic field. Binding experiments were carried out to evaluate the properties of magnetic MIPs and magnetic non-molecularly imprinted polymers (magnetic NIPs). The results demonstrated that the magnetic MIPs had high adsorption capacity and selectivity to ASP. Moreover, release profiles and release rate of ASP from the ASP-loaded magnetic MIPs indicated that the magnetic MIPs also had potential applications in drug controlled release.

  20. Imprint of DES superstructures on the cosmic microwave background

    Science.gov (United States)

    Kovács, A.; Sánchez, C.; García-Bellido, J.; Nadathur, S.; Crittenden, R.; Gruen, D.; Huterer, D.; Bacon, D.; Clampitt, J.; DeRose, J.; Dodelson, S.; Gaztañaga, E.; Jain, B.; Kirk, D.; Lahav, O.; Miquel, R.; Naidoo, K.; Peacock, J. A.; Soergel, B.; Whiteway, L.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Rosell, A. Carnero; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Eifler, T. F.; Finley, D. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Giannantonio, T.; Goldstein, D. A.; Gruendl, R. A.; Gutierrez, G.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Nord, B.; Ogando, R.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Sobreira, F.; Suchyta, E.; Swanson, M.; Tarle, G.; Thomas, D.; Walker, A. R.; DES Collaboration

    2017-03-01

    Small temperature anisotropies in the cosmic microwave background (CMB) can be sourced by density perturbations via the late-time integrated Sachs-Wolfe (ISW) effect. Large voids and superclusters are excellent environments to make a localized measurement of this tiny imprint. In some cases excess signals have been reported. We probed these claims with an independent data set, using the first year data of the Dark Energy Survey (DES) in a different footprint, and using a different superstructure finding strategy. We identified 52 large voids and 102 superclusters at redshifts 0.2 < z < 0.65. We used the Jubilee simulation to a priori evaluate the optimal ISW measurement configuration for our compensated top-hat filtering technique, and then performed a stacking measurement of the CMB temperature field based on the DES data. For optimal configurations, we detected a cumulative cold imprint of voids with ΔTf ≈ -5.0 ± 3.7 μK and a hot imprint of superclusters ΔTf ≈ 5.1 ± 3.2 μK; this is ∼1.2σ higher than the expected |ΔTf| ≈ 0.6 μK imprint of such superstructures in Λ cold dark matter (ΛCDM). If we instead use an a posteriori selected filter size (R/Rv = 0.6), we can find a temperature decrement as large as ΔTf ≈ -9.8 ± 4.7 μK for voids, which is ∼2σ above ΛCDM expectations and is comparable to previous measurements made using Sloan Digital Sky Survey superstructure data.

  1. Photoconjugation of molecularly imprinted polymer with magnetic nanoparticles

    OpenAIRE

    Xu, Changgang; Uddin, Khan Mohammad Ahsan; Shen, Xiantao; Jayawardena, Surangi; Yan, Mingdi; Ye, Lei

    2013-01-01

    Because of their synthetic accessibility, molecularly imprinted polymer (MIP) nanoparticles are ideal building blocks for preparing multifunctional composites. In this work we developed a general photo-coupling chemistry to enable simple conjugation of MIP nanoparticles with inorganic magnetic nanoparticles. We first synthesized MIP nanoparticles using propranolol as a model template and perfluorophenylazide-modified silica-coated magnetic nanoparticles. Using a simple photoactivation followe...

  2. Chemical Sensors Based on Molecularly Imprinted Sol-Gel Materials

    OpenAIRE

    Dickert, Franz L.; Lieberzeit, Peter A.; Adnan Mujahid

    2010-01-01

    The sol-gel technique is earning the worldwide attention of researchers in the field of material science, due to its versatility in synthesizing inorganic ceramic materials at mild conditions. High purity, homogeneity, controlled porosity, stable temperature and nanoscale structuring are the most remarkable features offered by this method for generating highly sensitive and selective matrices to incorporate analyte molecules. The crafting of sol-gel sensors through molecular imprinting has pu...

  3. Microcontact imprinted surface plasmon resonance sensor for myoglobin detection

    Energy Technology Data Exchange (ETDEWEB)

    Osman, Bilgen [Uludag University, Department of Chemistry, Bursa (Turkey); Uzun, Lokman [Hacettepe University, Department of Chemistry, Ankara (Turkey); Beşirli, Necati [Uludag University, Department of Chemistry, Bursa (Turkey); Denizli, Adil, E-mail: denizli@hacettepe.edu.tr [Hacettepe University, Department of Chemistry, Ankara (Turkey)

    2013-10-15

    In this study, we prepared surface plasmon resonance (SPR) sensor using the molecular imprinting technique for myoglobin detection in human serum. For this purpose, we synthesized myoglobin imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan methyl ester) [poly(HEMA-MATrp)] nanofilm on the surface of SPR sensor. We also synthesized non-imprinted poly(HEMA-MATrp) nanofilm without myoglobin for the control experiments. The SPR sensor was characterized with contact angle measurements, atomic force microscopy, X-ray photoelectron spectroscopy, and ellipsometry. We investigated the effectiveness of the sensor using the SPR system. We evaluated the ability of SPR sensor to sense myoglobin with myoglobin solutions (pH 7.4, phosphate buffer) in different concentration range and in the serum taken from a patient with acute myocardial infarction. We found that the Langmuir adsorption model was the most suitable for the sensor system. The detection limit was 87.6 ng/mL. In order to show the selectivity of the SPR sensor, we investigated the competitive detection of myoglobin, lysozyme, cytochrome c and bovine serum albumin. The results showed that the SPR sensor has high selectivity and sensitivity for myoglobin. - Highlights: • Micro-contact imprinted surface plasmon resonance sensor. • Real-time myoglobin detection in the serum taken from a patient with acute myocardial infarction • Reproducible results for consecutive myoglobin solution supplement • LOD and LOQ values of the SPR sensor were determined to be 26.3 and 87.6 ng/mL. • The SPR sensor has potential for myoglobin sensing during acute MI cases.

  4. Imprint of DES superstructures on the cosmic microwave background

    Energy Technology Data Exchange (ETDEWEB)

    Kovács, A.; Sánchez, C.; García-Bellido, J.; Nadathur, S.; Crittenden, R.; Gruen, D.; Huterer, D.; Bacon, D.; Clampitt, J.; DeRose, J.; Dodelson, S.; Gaztañaga, E.; Jain, B.; Kirk, D.; Lahav, O.; Miquel, R.; Naidoo, K.; Peacock, J. A.; Soergel, B.; Whiteway, L.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Rosell, A. Carnero; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D' Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Eifler, T. F.; Finley, D. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Giannantonio, T.; Goldstein, D. A.; Gruendl, R. A.; Gutierrez, G.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Nord, B.; Ogando, R.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Sobreira, F.; Suchyta, E.; Swanson, M.; Tarle, G.; Thomas, D.; Walker, A. R.

    2016-11-17

    Small temperature anisotropies in the Cosmic Microwave Background can be sourced by density perturbations via the late-time integrated Sachs-Wolfe effect. Large voids and superclusters are excellent environments to make a localized measurement of this tiny imprint. In some cases excess signals have been reported. We probed these claims with an independent data set, using the first year data of the Dark Energy Survey in a different footprint, and using a different super-structure finding strategy. We identified 52 large voids and 102 superclusters at redshifts $0.2 < z < 0.65$. We used the Jubilee simulation to a priori evaluate the optimal ISW measurement configuration for our compensated top-hat filtering technique, and then performed a stacking measurement of the CMB temperature field based on the DES data. For optimal configurations, we detected a cumulative cold imprint of voids with $\\Delta T_{f} \\approx -5.0\\pm3.7~\\mu K$ and a hot imprint of superclusters $\\Delta T_{f} \\approx 5.1\\pm3.2~\\mu K$ ; this is $\\sim1.2\\sigma$ higher than the expected $|\\Delta T_{f}| \\approx 0.6~\\mu K$ imprint of such super-structures in $\\Lambda$CDM. If we instead use an a posteriori selected filter size ($R/R_{v}=0.6$), we can find a temperature decrement as large as $\\Delta T_{f} \\approx -9.8\\pm4.7~\\mu K$ for voids, which is $\\sim2\\sigma$ above $\\Lambda$CDM expectations and is comparable to previous measurements made using SDSS super-structure data.

  5. Imprints of a critical point on photon emission

    Energy Technology Data Exchange (ETDEWEB)

    Wunderlich, F.; Kaempfer, B. [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universitaet Dresden, Institut fuer Theoretische Physik, Dresden (Germany)

    2016-08-15

    The linear sigma model with linearized fluctuations of all involved fields facilitates the onset of a sequence of first-order phase transitions at a critical point. This phase structure has distinctive imprints on the photon emission rates. We argue that analogously a critical point in the QCD phase diagram manifests itself by peculiarities of the photon spectra, in particular when the dynamical expansion path of matter crosses the phase transition curve in the vicinity of the critical point. (orig.)

  6. Influence of salt ions on binding to molecularly imprinted polymers.

    OpenAIRE

    Kempe, Henrik; Kempe, Maria

    2010-01-01

    Salt ions were found to have an influence on template binding to two model molecularly imprinted polymers (MIPs), targeted to penicillin G and propranolol, respectively, in water-acetonitrile mixtures. Water was detrimental to rebinding of penicillin G whereas propranolol bound in the entire water-acetonitrile range tested. In 100% aqueous solution, 3-M salt solutions augmented the binding of both templates. The effects followed the Hofmeister series with kosmotropic ions promoting the larges...

  7. Optimization of Shipboard Manning Levels Using Imprint Pro Forces Module

    Science.gov (United States)

    2015-09-01

    fleet we believe suffered because of it” ( Fuentes , 2011). In the case of the LCS, the initial aim was to achieve a core crew of only 40 sailors...software, with the assistance of Alion, in order to increase IMPRINT Pro utility for conducting Monte- Carlo simulations. We will also explore the...Department of the Navy. (2007). Navy total force manpower policies procedures – OPNAVIST 1000.16K. Washington, D.C.: Department of the Navy. Fuentes , G

  8. Production of abiotic receptors by molecular imprinting of proteins.

    OpenAIRE

    Braco, L.; Dabulis, K; Klibanov, A M

    1990-01-01

    When a protein is dissolved in a concentrated aqueous solution of a multifunctional organic compound, freeze-dried, and washed with an anhydrous organic solvent to remove the ligand, the resultant "imprinted" protein preparation binds up to 30-fold more of the template compound in anhydrous solvents than the nonimprinted protein in the same solvent (and both proteins in water). These artificial receptors exhibit marked ligand selectivity as well as stability in anhydrous media. This phenomeno...

  9. Absolute configuration determination using enantiomeric pairs of molecularly imprinted polymers.

    Science.gov (United States)

    Meador, Danielle S; Spivak, David A

    2014-03-07

    A new method for determination of absolute configuration (AC) is demonstrated using an enantiomeric pair of molecularly imprinted polymers, referred to as "DuoMIPs". The ratio of HPLC capacity factors (k') for the analyte on each of the DuoMIPs is defined as the γ factor and can be used to determine AC when above 1.2. A mnemonic based on the complementary binding geometry of the DuoMIPs was used to aid in understanding and prediction of AC.

  10. Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

    2017-01-01

    In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al...... patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption...

  11. Sexual imprinting on ecologically divergent traits leads to sexual isolation in sticklebacks.

    Science.gov (United States)

    Kozak, Genevieve M; Head, Megan L; Boughman, Janette W

    2011-09-07

    During sexual imprinting, offspring learn parental phenotypes and then select mates who are similar to their parents. Imprinting has been thought to contribute to the process of speciation in only a few rare cases; this is despite imprinting's potential to generate assortative mating and solve the problem of recombination in ecological speciation. If offspring imprint on parental traits under divergent selection, these traits will then be involved in both adaptation and mate preference. Such 'magic traits' easily generate sexual isolation and facilitate speciation. In this study, we show that imprinting occurs in two ecologically divergent stickleback species (benthics and limnetics: Gasterosteus spp.). Cross-fostered females preferred mates of their foster father's species. Furthermore, imprinting is essential for sexual isolation between species; isolation was reduced when females were raised without fathers. Daughters imprinted on father odour and colour during a critical period early in development. These traits have diverged between the species owing to differences in ecology. Therefore, we provide the first evidence that imprinting links ecological adaptation to sexual isolation between species. Our results suggest that imprinting may facilitate the evolution of sexual isolation during ecological speciation, may be especially important in cases of rapid diversification, and thus play an integral role in the generation of biodiversity.

  12. Development of a roll-to-roll thermal imprinting system with seamless belt-type template

    Science.gov (United States)

    Shan, X. C.; Chen, S. H.; Mohahidin, M. Bin; Wei, J.

    2017-08-01

    Compared to conventional thermal imprinting using a flat mold, roll-to-roll (R2R) thermal imprinting using a roller mold is a high-speed, high through-put process. In an R2R thermal imprinting process, however, the contact duration between a mold and a thermoplastic substrate is extremely short. This results in insufficient heating and pressing, leading to low fidelity of the imprinted microstructures. We have developed an R2R thermal imprinting system, which allows us to extend the contact duration between the mold and substrate. This system consists of two continuous, seamless belts that are made of metal foil. Each belt is driven by an individual hot roller; at least one belt is used as an imprinting mold, another as a carrier belt. A thermoplastic film to be imprinted is sandwiched between the two belts that provide preheating, heating and pressing, holding, and cooling for demolding during imprinting, leading to extended mold-substrate contact duration and enhanced heat transfer from the belt mold to the polymer film. R2R thermal imprinting has been performed successfully and promising results have been demonstrated.

  13. Demonstration of a neural circuit critical for imprinting behavior in chicks.

    Science.gov (United States)

    Nakamori, Tomoharu; Sato, Katsushige; Atoji, Yasuro; Kanamatsu, Tomoyuki; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

    2010-03-24

    Imprinting behavior in birds is elicited by visual and/or auditory cues. It has been demonstrated previously that visual cues are recognized and processed in the visual Wulst (VW), and imprinting memory is stored in the intermediate medial mesopallium (IMM) of the telencephalon. Alteration of neural responses in these two regions according to imprinting has been reported, yet direct evidence of the neural circuit linking these two regions is lacking. Thus, it remains unclear how memory is formed and expressed in this circuit. Here, we present anatomical as well as physiological evidence of the neural circuit connecting the VW and IMM and show that imprinting training during the critical period strengthens and refines this circuit. A functional connection established by imprint training resulted in an imprinting behavior. After the closure of the critical period, training could not activate this circuit nor induce the imprinting behavior. Glutamatergic neurons in the ventroposterior region of the VW, the core region of the hyperpallium densocellulare (HDCo), sent their axons to the periventricular part of the HD, just dorsal and afferent to the IMM. We found that the HDCo is important in imprinting behavior. The refinement and/or enhancement of this neural circuit are attributed to increased activity of HDCo cells, and the activity depended on NR2B-containing NMDA receptors. These findings show a neural connection in the telencephalon in Aves and demonstrate that NR2B function is indispensable for the plasticity of HDCo cells, which are key mediators of imprinting.

  14. In Pursuit of New Imprinting Syndromes by Epimutation Screening in Idiopathic Neurodevelopmental Disorder Patients

    Directory of Open Access Journals (Sweden)

    Sonia Mayo

    2015-01-01

    Full Text Available Alterations of epigenetic mechanisms, and more specifically imprinting modifications, could be responsible of neurodevelopmental disorders such as intellectual disability (ID or autism together with other associated clinical features in many cases. Currently only eight imprinting syndromes are defined in spite of the fact that more than 200 genes are known or predicted to be imprinted. Recent publications point out that some epimutations which cause imprinting disorders may affect simultaneously different imprinted loci, suggesting that DNA-methylation may have been altered more globally. Therefore, we hypothesised that the detection of altered methylation patterns in known imprinting loci will indirectly allow identifying new syndromes due to epimutations among patients with unexplained ID. In a screening for imprinting alterations in 412 patients with syndromic ID/autism we found five patients with altered methylation in the four genes studied: MEG3, H19, KCNQ1OT1, and SNRPN. Remarkably, the cases with partial loss of methylation in KCNQ1OT1 and SNRPN present clinical features different to those associated with the corresponding imprinting syndromes, suggesting a multilocus methylation defect in accordance with our initial hypothesis. Consequently, our results are a proof of concept that the identification of epimutations in known loci in patients with clinical features different from those associated with known syndromes will eventually lead to the definition of new imprinting disorders.

  15. Imprinting Salmon and Steelhead Trout for Homing, 1983 Annual Report of Research.

    Energy Technology Data Exchange (ETDEWEB)

    Slatick, Emil

    1984-09-01

    The National Marine Fisheries Service (NMFS), under contract to the Bonneville Power Administration, began conducting research on imprinting Pacific salmon and steelhead for homing in 1978. In the juvenile marking phase, over 4 million juvenile salmon and steelhead were marked and released in 23 experiments. The primary objectives were to determine a triggering mechanism to activate the homing imprint, if a single imprint or a sequential imprint is necessary to assure homing, and the relationship between the physiological condition of fish and their ability to imprint. Ten experimental studies are discussed. Six of the studies employed a variety of techniques for imprinting fish. The remaining four tested the feasibility of imprinting fish by a short-distance voluntary migration before transport. In five experiments, survival was enhanced by the imprint-transportation procedures, and homing to the homing site area was partly successful. Returns from the Astoria, Oregon, release of fall chinook salmon from Big Creek Hatchery (Knappa, Oregon), for example, showed that limited short distance migration imprinting should provide 2-3 time more fish to the various fisheries while providing adequate returns to the hatchery for egg take each year. 21 refs., 12 figs, 12 tabs.

  16. Selective Solid-phase Extraction of Aloe Emodin from Aloe by Molecularly Imprinted Polymers

    Institute of Scientific and Technical Information of China (English)

    TIAN Ming-lei; LEE Yu-ri; PARK Dong-wha; ROW Kyung-ho

    2013-01-01

    The extraction and separation of aloe emodin were optimized via selective molecularly imprinted solid-phase extraction.Molecularly imprinted polymer was prepared from the functional monomer,methacrylic acid and a mixture of ethanol/dodecanol(90/10,volume ratio) as porogen.It overcomes the common problems of imprinting biological polar compounds and shows high selectivity compared favorably with those of non-imprinted polymer and commercially available C18 and silica cartridges in similar aloe emodin tests.Good linearity was obtained between 0.002 and 2.5 mg/mL(r2=0.998) with relative standard deviations below 3.3%.

  17. MOLECULAR IMPRINTED SOLID PHASE EXTRACTION FOR DETERMINATION OF ATRAZINE IN ENVIRONMENTAL SAMPLES

    Directory of Open Access Journals (Sweden)

    A. R. Koohpaei ، S. J. Shahtaheri ، M. R. Ganjali ، A. Rahimi Forushani

    2008-10-01

    Full Text Available Solid phase extraction is one of the major applications of molecularly imprinted polymers fields for clean-up of environmental and biological samples namely molecularly imprinted solid-phase extraction. In this study, solid phase extraction using the imprinted polymer has been optimized with the experimental design approach for a triazine herbicide, named atrazine with regard to the critical factors which influence the molecular imprinted solid phase extraction efficiency such as sample pH, concentration, flow-rate, volume, elution solvent, washing solvent and sorbent mass. Optimization methods that involve changing one factor at a time can be laborious. A novel approach for the optimization of imprinted solid-phase extraction using chemometrics is described. The factors were evaluated statistically and also validated with spiked water samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. Also, in order to the evaluate efficiency of the optimized molecularly imprinted solid-phase extraction protocols, enrichment capacity, reusability and cross-reactivity of cartridges have been also evaluated. Finally, selective molecularly imprinted solid-phase extraction of atrazine was successfully demonstrated with a recovery above 90% for spiked drinking water samples. It was concluded that the chemometrics is frequently employed for analytical method optimization and based on the obtained results, it is believed that the central composite design could prove beneficial for aiding the molecularly imprinted polymer and molecularly imprinted solid-phase extraction development.

  18. Selective enrichment and separation of phosphotyrosine peptides by thermosensitive molecularly imprinted polymers.

    Science.gov (United States)

    Yang, Xiaoqing; Xia, Yan

    2016-01-01

    Novel thermosensitive molecularly imprinted polymers were successfully prepared using the epitope imprinting approach in the presence of the mimic template phenylphosphonic acid, the functional monomer vinylphosphonic acid-Ti(4+) , the temperature-sensitive monomer N-isopropylacrylamide and the crosslinker N,N'-methylenebisacrylamide. The ratio of the template/thermosensitive monomers/crosslinker was optimized, and when the ratio was 2:2:1, the prepared thermosensitive molecularly imprinted polymers had the highest imprinting factor. The synthetic thermosensitive molecularly imprinted polymers were characterized by Fourier transform infrared spectroscopy to reveal the combination and elution processes of the template. Then, the adsorption capacity and thermosensitivity was measured. When the temperature was 28°C, the imprinting factor was the highest. The selectivity and adsorption capacity of the thermosensitive molecularly imprinted polymers for phosphotyrosine peptides from a mixture of three tailor-made peptides were measured by high-performance liquid chromatography. The results showed that the thermosensitive molecularly imprinted polymers have good selectivity for phosphotyrosine peptides. Finally, the imprinted hydrogels were applied to specifically adsorb phosphotyrosine peptides from a sample mixture containing phosphotyrosine and a tryptic digest of β-casein, which demonstrated high selectivity. After four rebinding cycles, 78.9% adsorption efficiency was still retained.

  19. Ordered macroporous quercetin molecularly imprinted polymers: Preparation, characterization, and separation performance.

    Science.gov (United States)

    Feng, Yonggang; Liu, Qin; Ye, Lifang; Wu, Quanzhou; He, Jianfeng

    2017-02-01

    Ordered macroporous molecularly imprinted polymers were prepared by a combination of the colloidal crystal templating method and the molecular imprinting technique by using SiO2 colloidal crystal as the macroporogen, quercetin as the imprinting template, acrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and tetrahydrofuran as the solvent. Scanning electron microscopy and Brunauer-Emmett-Teller measurements show that the ordered macroporous molecularly imprinted polymers have a more regular macroporous structure, a narrower pore distribution and a greater porosity compared with the traditional bulk molecularly imprinted polymers. The kinetic and isothermal adsorption behaviors of the polymers were investigated. The results indicate that the ordered macroporous molecularly imprinted polymers have a faster intraparticle mass transfer process and a higher adsorption capacity than the traditional bulk molecularly imprinted polymers. The ordered macroporous molecularly imprinted polymers were further employed as a sorbent for a solid-phase extraction. The results show that the ordered macroporous molecularly imprinted polymers can effectively separate quercetin from the Gingko hydrolysate.

  20. In Pursuit of New Imprinting Syndromes by Epimutation Screening in Idiopathic Neurodevelopmental Disorder Patients.

    Science.gov (United States)

    Mayo, Sonia; Monfort, Sandra; Roselló, Mónica; Oltra, Silvestre; Orellana, Carmen; Martínez, Francisco

    2015-01-01

    Alterations of epigenetic mechanisms, and more specifically imprinting modifications, could be responsible of neurodevelopmental disorders such as intellectual disability (ID) or autism together with other associated clinical features in many cases. Currently only eight imprinting syndromes are defined in spite of the fact that more than 200 genes are known or predicted to be imprinted. Recent publications point out that some epimutations which cause imprinting disorders may affect simultaneously different imprinted loci, suggesting that DNA-methylation may have been altered more globally. Therefore, we hypothesised that the detection of altered methylation patterns in known imprinting loci will indirectly allow identifying new syndromes due to epimutations among patients with unexplained ID. In a screening for imprinting alterations in 412 patients with syndromic ID/autism we found five patients with altered methylation in the four genes studied: MEG3, H19, KCNQ1OT1, and SNRPN. Remarkably, the cases with partial loss of methylation in KCNQ1OT1 and SNRPN present clinical features different to those associated with the corresponding imprinting syndromes, suggesting a multilocus methylation defect in accordance with our initial hypothesis. Consequently, our results are a proof of concept that the identification of epimutations in known loci in patients with clinical features different from those associated with known syndromes will eventually lead to the definition of new imprinting disorders.

  1. Evidence of Olfactory Imprinting at an Early Life Stage in Pink Salmon (Oncorhynchus gorbuscha).

    Science.gov (United States)

    Bett, Nolan N; Hinch, Scott G; Dittman, Andrew H; Yun, Sang-Seon

    2016-11-09

    Pacific salmon (Oncorhynchus spp.) navigate towards spawning grounds using olfactory cues they imprinted on as juveniles. The timing at which imprinting occurs has been studied extensively, and there is strong evidence that salmon imprint on their natal water during the parr-smolt transformation (PST). Researchers have noted, however, that the life histories of some species of Pacific salmon could necessitate imprinting prior to the PST. Juvenile pink salmon (O. gorbuscha) spend less time in fresh water than any other species of Pacific salmon, and presumably must imprint on their natal water at a very young age. The time at which imprinting occurs in this species, however, has not been experimentally tested. We exposed juvenile pink salmon as alevins to phenethyl alcohol (PEA) or control water, reared these fish to adulthood, and then tested their behavioural responses to PEA to determine whether the fish successfully imprinted. We found that pink salmon exposed to PEA as alevins were attracted to the chemical as adults, suggesting that imprinting can occur during this stage. Our finding provides some of the first evidence to support the long-standing belief that imprinting can occur in pink salmon prior to the PST.

  2. Imprinted functionalized silica sol-gel for solid-phase extraction of triazolamin.

    Science.gov (United States)

    Jin, Guoyou; Zhang, Baofei; Tang, Youwen; Zuo, Xiongjun; Wang, Songcai; Tang, Jingyi

    2011-05-15

    A triazolam-imprinted silica microsphere was prepared by combining a surface molecular-imprinting technique with the sol-gel process. The results illustrate that the triazolam-imprinted silica microspheres provided using γ-aminopropyltriethoxysilane and phenyltrimethoxysilane as monomers exhibited higher selectivity than those provided from γ-aminopropyltriethoxysilane and methyltriethoxysilane. In addition, the optimum affinity occurred when the molar ratio of γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, and the template molecule was 4.2:4.7:0.6. Retention factor (k) and imprinting factor (IF) of triazolam on the imprinted and non-imprinted silica microsphere columns were characterized using high performance liquid chromatography (HPLC) with different mobile phases including methanol, acetonitrile, and water solutions. The molecular selectivity of the imprinted silica microspheres was also evaluated for triazolam and its analogue compounds in various mobile phases. The better results indicated that k and IF of triazolam on the imprinted silica microsphere column were 2.1 and 35, respectively, when using methanol/water (1/1, v/v) as the mobile phase. Finally, the imprinted silica was applied as a sorbent in solid-phase extraction (SPE), to selectively extract triazolam and its metabolite, α-hydroxytriazolam, from human urine samples. The limits of detection (LOD) for triazolam and α-hydroxytriazolam in urine samples were 30 ± 0.21 ng mL(-1) and 33 ± 0.26 ng mL(-1), respectively.

  3. Touch imprint cytology: a rapid diagnostic tool for oral squamous cell carcinoma.

    Science.gov (United States)

    Geetha, L; Astekar, M; Ashok, K N; Sowmya, G V

    2015-07-01

    Techniques for intraoperative pathologic examination of oral squamous cell carcinoma are rare in the literature. We evaluated the advantages and limitations of touch imprint cytology for intraoperative diagnosis of oral squamous cell carcinoma. We used 30 incisional biopsies of clinically diagnosed oral squamous cell carcinoma and compared touch imprint cytology to histopathological sections. Touch imprint cytology showed 24 specimens positive for malignancy, two suspicious for malignancy and four inadequate specimens. The accuracy of the test was 93.2%. Touch imprint cytology is an accurate, simple, rapid and cost-effective method that aids diagnosis of oral squamous cell carcinoma during operation, but it does not replace incisional biopsy.

  4. Sexual imprinting can induce sexual preferences for exaggerated parental traits.

    Science.gov (United States)

    ten Cate, Carel; Verzijden, Machteld N; Etman, Eric

    2006-06-06

    Sexual preferences in animals are often skewed toward mates with exaggerated traits. In many vertebrates, parents provide, through the learning process of "sexual imprinting," the model for the later sexual preference. How imprinting can result in sexual preferences for mates having exaggerated traits rather than resembling the parental appearance is not clear. We test the hypothesis that a by-product of the learning process, "peak shift", may induce skewed sexual preferences for exaggerated parental phenotypes. To this end, zebra finch (Taeniopygia guttata) males were raised by white parents, with beak color as the most prominent sexual dimorphism. We manipulated this feature with nail varnish. At adult age, each male was given a preference test in which he could choose among eight females with beak colors ranging from more extreme on the paternal to more extreme on the maternal side. The males preferred females with a beak of a more extreme color than that of their mothers, i.e., they showed a peak shift. Sexual imprinting can thus generate skewed sexual preferences for exaggerated maternal phenotypes, phenotypes that have not been present at the time of the learning. We suggest that such preferences can drive the evolution of sexual dimorphism and exaggerated sexual traits.

  5. Detour behaviour, imprinting and visual lateralization in the domestic chick.

    Science.gov (United States)

    Vallortigara, G; Regolin, L; Pagni, P

    1999-01-01

    Detour behaviour was studied in chicks faced with a vertical-bar barrier behind where an imprinting object (a red ball) was located. Right-eyed chicks took less time to detour the barrier than left-eyed chicks, and binocular chicks showed a bias to detour the barrier on the left side, thus maintaining visual contact with the imprinting object using the lateral field of the right eye, while circling around the barrier. In males, the asymmetries were consistent all along the first two weeks of life, whereas in females they disappeared on days 8 and 11. When tested with a slightly novel version of the original imprinting object (i.e., a ball of a different color), binocular chicks showed a bias to detour the barrier on the right side, thus showing preferential use of the left eye. The same bias occurred when unfamiliar conspecifics were used as goal-objects. Results suggest that cerebral lateralization in birds can directly affect visually-guided motor responses through selective use of the lateral field of vision of the eye contralateral to the hemisphere which has to be put in charge of control of overt behaviour. Copyright 1999 Elsevier Science B.V.

  6. Critical review and perspective of macromolecularly imprinted polymers.

    Science.gov (United States)

    Kryscio, David R; Peppas, Nicholas A

    2012-02-01

    Molecular recognition is a fundamental and ubiquitous process that is the driving force behind life. Natural recognition elements - including antibodies, enzymes, nucleic acids, and cells - exploit non-covalent interactions to bind to their targets with exceptionally strong affinities. Due to this unparalleled proficiency, scientists have long sought to mimic natural recognition pathways. One promising approach is molecularly imprinted polymers (MIPs), which are fully synthetic systems formed via the crosslinking of organic polymers in the presence of a template molecule, which results in stereo-specific binding sites for this analyte of interest. Macromolecularly imprinted polymers, those synthesized in the presence of macromolecule templates (>1500 Da), are of particular importance because they open up the field for a whole new set of robust diagnostic tools. Although the specific recognition of small-molecular-weight analytes is now considered routine, extension of these efficacious procedures to the protein regime has, thus far, proved challenging. This paper reviews the main approaches employed, highlights studies of interest with an emphasis on recent work, and offers suggestions for future success in the field of macromolecularly imprinted polymers.

  7. Shape-engineered multifunctional porous silicon nanoparticles by direct imprinting.

    Science.gov (United States)

    Mares, Jeremy W; Fain, Joshua S; Beavers, Kelsey R; Duvall, Craig L; Weiss, Sharon M

    2015-07-10

    A versatile and scalable method for fabricating shape-engineered nano- and micrometer scale particles from mesoporous silicon (PSi) thin films is presented. This approach, based on the direct imprinting of porous substrates (DIPS) technique, facilitates the generation of particles with arbitrary shape, ranging in minimum dimension from approximately 100 nm to several micrometers, by carrying out high-pressure (>200 MPa) direct imprintation, followed by electrochemical etching of a sub-surface perforation layer and ultrasonication. PSi particles (PSPs) with a variety of geometries have been produced in quantities sufficient for biomedical applications (≫10 μg). Because the stamps can be reused over 150 times, this process is substantially more economical and efficient than the use of electron beam lithography and reactive ion etching for the fabrication of nanometer-scale PSPs directly. The versatility of this fabrication method is demonstrated by loading the DIPS-imprinted PSPs with a therapeutic peptide nucleic acid drug molecule, and by vapor deposition of an Au coating to facilitate the use of PSPs as a photothermal contrast agent.

  8. Monolithic molecularly imprinted polymeric capillary columns for isolation of aflatoxins.

    Science.gov (United States)

    Szumski, Michał; Grzywiński, Damian; Prus, Wojciech; Buszewski, Bogusław

    2014-10-17

    Monolithic molecularly imprinted polymers extraction columns have been prepared in fused-silica capillaries by UV or thermal polymerization in a two-step process. First, a poly-(trimethylolpropane trimethacrylate) (polyTRIM) core monolith was synthesized either by UV or thermal polymerization. Then it was grafted with the mixture of methacrylic acid (MAA) as a functional monomer, ethylene dimethacrylate (EDMA) as a cross-linking agent, 5,7-dimethoxycoumarin (DMC) as an aflatoxin-mimicking template, toluene as a porogen solvent and 2,2-azobis-(2-methylpropionitrile) (AIBN) as an initiator of the polymerization reaction. Different thermal condition of the photografting and different concentrations of the grafting mixture were tested during polymerization. The extraction capillary columns were evaluated in the terms of their hydrodynamic and chromatographic properties. Retention coefficients for aflatoxin B1 and DMC were used for assessment of the selectivity and imprinting factor. The obtained results indicate that the temperature of photografting and concentration of the grafting mixture are key parameters that determine the quality of the prepared MIPs. From the MIP columns characterized by the highest permeability the column of the highest imprinting factor was applied for isolation of aflatoxins B1, B2, G1 and G2 from the model aqueous sample followed by on-line chromatographic separation. The process was performed using a micro-MISPE-microLC-LIF system of a novel design, which allowed for detection of the eluates from the sample preparation part as well as from the chromatographic separation.

  9. Feature detection on 3D images of dental imprints

    Science.gov (United States)

    Mokhtari, Marielle; Laurendeau, Denis

    1994-09-01

    A computer vision approach for the extraction of feature points on 3D images of dental imprints is presented. The position of feature points are needed for the measurement of a set of parameters for automatic diagnosis of malocclusion problems in orthodontics. The system for the acquisition of the 3D profile of the imprint, the procedure for the detection of the interstices between teeth, and the approach for the identification of the type of tooth are described, as well as the algorithm for the reconstruction of the surface of each type of tooth. A new approach for the detection of feature points, called the watershed algorithm, is described in detail. The algorithm is a two-stage procedure which tracks the position of local minima at four different scales and produces a final map of the position of the minima. Experimental results of the application of the watershed algorithm on actual 3D images of dental imprints are presented for molars, premolars and canines. The segmentation approach for the analysis of the shape of incisors is also described in detail.

  10. Morpho peleides butterfly wing imprints as structural colour stamp.

    Science.gov (United States)

    Zobl, Sigrid; Salvenmoser, Willi; Schwerte, Thorsten; Gebeshuber, Ille C; Schreiner, Manfred

    2016-02-02

    This study presents the replication of a color-causing nanostructure based on the upper laminae of numerous cover scales of Morpho peleides butterfly wings and obtained solely by imprinting their upper-wing surfaces. Our results indicate that a simple casting technique using a novel integrated release agent can obtain a large positive replica using negative imprints via Polyvinylsiloxane. The developed method is low-tech and high-yield and is thus substantially easier and less expensive than previous methods. The microstructures were investigated with light microscopy, the nanostructures with both scanning and transmission electron microscopy, and the reflections with UV visible spectrometry. The influence of the release agent and the quality of the master stamp were determined by comparing measurements of the cover-scale sizes and their chromaticity values obtained by their images and with their positive imprints. The master stamp provided multiple positive replicas up to 3 cm(2) in just 1 h with structural coloration effects visible to the naked eye. Thus, the developed method proves the accuracy of the replicated nanostructure and its potential industrial application as a color-producing nanostamp.

  11. Predicting the performance of molecularly imprinted polymers: Selective extraction of caffeine by molecularly imprinted solid phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Farrington, Keith [School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland); Magner, Edmond [Materials and Surface Science Institute, Chemical and Environmental Sciences Department, University of Limerick, Limerick (Ireland); Regan, Fiona [School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland)]. E-mail: fiona.regan@dcu.ie

    2006-04-27

    A rational design approach was taken to the planning and synthesis of a molecularly imprinted polymer capable of extracting caffeine (the template molecule) from a standard solution of caffeine and further from a food sample containing caffeine. Data from NMR titration experiments in conjunction with a molecular modelling approach was used in predicting the relative ratios of template to functional monomer and furthermore determined both the choice of solvent (porogen) and the amount used for the study. In addition the molecular modelling program yielded information regarding the thermodynamic stability of the pre-polymerisation complex. Post-polymerisation analysis of the polymer itself by analysis of the pore size distribution by BET yielded significant information regarding the nature of the size and distribution of the pores within the polymer matrix. Here is proposed a stepwise procedure for the development and testing of a molecularly imprinted polymer using a well-studied compound-caffeine as a model system. It is shown that both the physical characteristics of a molecularly imprinted polymer (MIP) and the analysis of the pre-polymerisation complex can yield vital information, which can predict how well a given MIP will perform.

  12. Mapping the double-strand breaks at the mating-type locus in fission yeast by genomic sequencing

    DEFF Research Database (Denmark)

    Nielsen, O; Egel, R; Nielsen, Olaf

    1989-01-01

    In fission yeast mating-type switching is initiated by the formation of a double-strand DNA break at the mating-type locus. A prerequisite for generation of the break is some 'imprinting' of the DNA in the previous cell cycle. We have used the technique of genomic sequencing to map the position o...

  13. Cancer genomics

    DEFF Research Database (Denmark)

    Norrild, Bodil; Guldberg, Per; Ralfkiær, Elisabeth Methner

    2007-01-01

    Almost all cells in the human body contain a complete copy of the genome with an estimated number of 25,000 genes. The sequences of these genes make up about three percent of the genome and comprise the inherited set of genetic information. The genome also contains information that determines whe...

  14. Modeling genetic imprinting effects of DNA sequences with multilocus polymorphism data

    Directory of Open Access Journals (Sweden)

    Staud Roland

    2009-08-01

    Full Text Available Abstract Single nucleotide polymorphisms (SNPs represent the most widespread type of DNA sequence variation in the human genome and they have recently emerged as valuable genetic markers for revealing the genetic architecture of complex traits in terms of nucleotide combination and sequence. Here, we extend an algorithmic model for the haplotype analysis of SNPs to estimate the effects of genetic imprinting expressed at the DNA sequence level. The model provides a general procedure for identifying the number and types of optimal DNA sequence variants that are expressed differently due to their parental origin. The model is used to analyze a genetic data set collected from a pain genetics project. We find that DNA haplotype GAC from three SNPs, OPRKG36T (with two alleles G and T, OPRKA843G (with alleles A and G, and OPRKC846T (with alleles C and T, at the kappa-opioid receptor, triggers a significant effect on pain sensitivity, but with expression significantly depending on the parent from which it is inherited (p = 0.008. With a tremendous advance in SNP identification and automated screening, the model founded on haplotype discovery and statistical inference may provide a useful tool for genetic analysis of any quantitative trait with complex inheritance.

  15. EFFECTS OF PRIMARY IMPRINTING ON THE SUBSEQUENT DEVELOPMENT OF SECONDARY FILIAL ATTACHMENTS IN THE CHICK

    NARCIS (Netherlands)

    DEVOS, GJ; VANKAMPEN, HS

    This study reinvestigates the effects of primary imprinting of chicks with either a naturalistic stimulus or an artificial object on subsequent imprinting with artificial objects. Initial experience with a live chick (group C) or a yellow cylinder (group Y) had differential effects on the

  16. A framework for the study of filial imprinting and the development of attachment

    NARCIS (Netherlands)

    vanKampen, HS

    Filial imprinting is the process through which early attachment behavior becomes restricted to the mother and siblings. In the present paper it will be shown that the processes underlying imprinting in chicks (Gallus gallus) can be fruitfully analyzed by referring to the same mechanisms as are

  17. Elevated expression of brain-derived neurotrophic factor facilitates visual imprinting in chicks.

    Science.gov (United States)

    Suzuki, Keiko; Maekawa, Fumihiko; Suzuki, Shingo; Nakamori, Tomoharu; Sugiyama, Hayato; Kanamatsu, Tomoyuki; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

    2012-12-01

    With the aim of elucidating the neural mechanisms of early learning, we studied the role of brain-derived neurotrophic factor (BDNF) in visual imprinting in birds. The telencephalic neural circuit connecting the visual Wulst and intermediate medial mesopallium is critical for imprinting, and the core region of the hyperpallium densocellulare (HDCo), situated at the center of this circuit, has a key role in regulating the activity of the circuit. We found that the number of BDNF mRNA-positive cells in the HDCo was elevated during the critical period, particularly at its onset, on the day of hatching (P0). After imprinting training on P1, BDNF mRNA-positive cells in the HDCo increased in number, and tyrosine phosphorylation of TrkB was observed. BDNF infusion into the HDCo at P1 induced imprinting, even with a weak training protocol that does not normally induce imprinting. In contrast, K252a, an antagonist of Trk, inhibited imprinting. Injection of BDNF at P7, after the critical period, did not elicit imprinting. These results suggest that BDNF promotes the induction of imprinting through TrkB exclusively during the critical period. © 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.

  18. Smart electrochemical sensor for some neurotransmitters using imprinted sol-gel films.

    Science.gov (United States)

    Atta, Nada F; Abdel-Mageed, Ali M

    2009-12-15

    A hybrid sol-gel material formed by acid hydrolysis of a mixture of tetraethylorthosilicate (TEOS) and phenyltriethylorthosilicate (PTEOS) as functional monomers was imprinted by tyramine and dopamine as template molecules for the purpose of molecular recognition. Imprinted materials were spin coated as thin films on the surface of glassy carbon electrodes and then were characterized using cyclic voltammetry (CV). After extraction of the encapsulated molecules, imprinted films were tested in solutions of their templates and other molecules. Rebinding experiments were followed by electrochemical characterization using square wave voltammetry (SWV). Imprinted films showed higher affinities toward their template molecules compared to other structurally similar molecules especially for tyramine imprinted film. With the exception of tyramine and norepinephrine, the interference level did not exceed 5% for all compounds studied for dopamine-imprinted films. Tyramine-imprinted films however showed high affinity to tyramine with dopamine 40% interference. Some factors related to the rebinding ability process like pH of solution, concentration of template were studied. The sensing surface lifetime extended to 2 weeks with decay in response signal that ranged from 22%, 40% to 60% for dopamine, tyramine and norepinephrine, respectively. The standard deviation from the mean of measurements for the repeated experiments is 7.4%. Electrochemical impedance spectroscopy (EIS) measurements confirmed the results obtained by electrochemical measurements. Morphological characteristics of the imprinted thin films and their thickness were investigated using scanning electron microscope (SEM).

  19. Imprinting of Phenylalanine ethyl ester in cyclodextrin polymers in aqueous solution

    DEFF Research Database (Denmark)

    Detcheva, Anna Hr.; Yu, Donghong; Larsen, Kim Lambertsen

    During the last decades there has been a wide interest of developing molecularly imprinted polymers, which selectively can recognize small molecules. Cyclodextrins offer relatively strong binding site of a wide range of small molecules in water and molecular imprinted polymers of these have previ...

  20. Charged hydrogels for post-loading, release, and molecular imprinting of proteins

    NARCIS (Netherlands)

    Schillemans, J.P.

    2010-01-01

    Molecular imprinting is a technique to create template-shaped cavities in polymer matrices with memory of the template molecules, to be used in molecular recognition. Molecular imprinting of low molecular weight compounds is a well established technique used to create high affinity materials. On the

  1. Removal of cefalexin using yeast surface-imprinted polymer prepared by atom transfer radical polymerization.

    Science.gov (United States)

    Li, Xiuxiu; Pan, Jianming; Dai, Jiangdong; Dai, Xiaohui; Ou, Hongxiang; Xu, Longcheng; Li, Chunxiang; Zhang, Rongxian

    2012-10-01

    The first use of yeast as a support in the molecular imprinting field combined with atom transfer radical polymerization was described. Then, the as-prepared molecularly imprinted polymers were characterized by Fourier transmission infrared spectrometry, scanning electron microscope, thermogravimetric analysis, and elemental analysis. The obtained imprinted polymers demonstrated elliptical-shaped particles with the thickness of imprinting layer of 0.63 μm. The batch mode experiments were adopted to investigate the adsorption equilibrium, kinetics, and selectivity. The kinetic properties of imprinted polymers were well described by the pseudo-second-order kinetic equation, indicating the chemical process was the rate-limiting step for the adsorption of cefalexin (CFX). The equilibrium data were well fitted by the Freundlich isotherm, and the multimolecular layers adsorption capacity of imprinted polymers was 34.07 mg g(-1) at 298 K. The selectivity analysis suggested that the imprinted polymers exhibited excellent selective recognition for CFX in the presence of other compounds with related structure. Finally, the analytical method based on the imprinted polymers extraction coupled with high-performance liquid chromatograph was successfully used for CFX analysis in spiked pork and water samples.

  2. Magnetic-graphene based molecularly imprinted polymer nanocomposite for the recognition of bovine hemoglobin.

    Science.gov (United States)

    Guo, Junxia; Wang, Yuzhi; Liu, Yanjin; Zhang, Cenjin; Zhou, Yigang

    2015-11-01

    The protein imprinted technique combining surface imprinting and nanomaterials has been an attractive strategy for recognition and rapid separation of proteins. In this work, magnetic-graphene (MG) was chosen as the supporting substrate for the magnetic nanomaterials, which served to absorb the targeting imprinting molecules, bovine hemoglobin (BHb). Acryl amide (AAm) with a high affinity to BHb and N,N'- methylenebisacrylamide (MBA) were selected as the functional monomer and cross-linking agent, respectively. After in-situ polymerization, the proposed magnetic-graphene based molecularly imprinted polymer (MG-MIP) was obtained with a further extraction step of imprinted BHb. Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), raman spectroscopy(RS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were employed to characterize the resulted MG-MIP. The maximum adsorption capability (Qmax) was determined by Langmuir Isotherm Plots and was 186.73 mg/g for imprinted nanomaterials (MIP) with an imprinting factor of 1.96. The selectivity of MG-MIP was investigated by using several proteins that are different in molecular mass and isoelectric points as the reference. The results showed that the shape memory effect of imprinted cavities, the size of proteins and the charge effect of proteins were the major factors for the selective recognition. The proposed method was also employed to specifically capture BHb from a binary protein mixture.

  3. Removal of toxic mercury from petroleum oil by newly synthesized molecularly-imprinted polymer.

    Science.gov (United States)

    Khairi, Nor Ain Shahera; Yusof, Nor Azah; Abdullah, Abdul Halim; Mohammad, Faruq

    2015-05-08

    In recent years, molecularly-imprinted polymers (MIPs) have attracted the attention of several researchers due to their capability for molecular recognition, easiness of preparation, stability and cost-effective production. By taking advantage of these facts, Hg(II) imprinted and non-imprinted copolymers were prepared by polymerizing mercury nitrate stock solution (or without it) with methacrylic acid (MAA), 2-hydroxyl ethyl methacrylate (HEMA), methanol and ethylene glycol dimethacrylate (EGDMA) as the monomer, co-monomer solvent (porogen) and cross-linker, respectively. Thus, the formed Hg(II) imprinted polymer was characterized by using Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), Brunauer, Emmett and Teller (BET) and thermal gravimetric analysis (TGA). The separation and preconcentration characteristics of Hg(II) imprinted polymer were investigated by solid phase extraction (SPE) procedures, and an optimal pH of 7 was investigated as ideal. The specific surface area of the Hg(II) imprinted polymer was found to be 19.45 m2/g with a size range from 100 to 140 µm in diameter. The maximum adsorption capacity was observed to be 1.11 mg/g of Hg(II) imprinted beads with 87.54% removal of Hg(II) ions within the first 5 min. The results of the study therefore confirm that the Hg(II) imprinted polymer can be used multiple times without significantly losing its adsorption capacity.

  4. An innovative approach to molecularly imprinted capillaries for polar templates by grafting polymerization.

    Science.gov (United States)

    Giovannoli, Cristina; Passini, Cinzia; Baravalle, Patrizia; Anfossi, Laura; Giraudi, Gianfranco; Baggiani, Claudio

    2012-06-01

    Molecularly imprinted polymers have been successfully used as selective stationary phases in capillary electrophoresis. Notwithstanding, this technique suffers from several drawbacks as the loss of molecular recognition properties in aqueous media and the lack of feasibility for imprinted systems directed towards highly polar templates soluble in aqueous environments only. Thus, the preparation of imprinted polymers for highly polar, water-soluble analytes, represents a challenge. In this work, we present an innovative approach to overcome these drawbacks. It is based on a surface molecular imprinting technique that uses preformed macromonomers as both functional recognition elements and cross-linking agents. A poly-2-hydroxyethyl-co-methacrylic acid linear polymer was grafted from the surface of silica capillaries. The grafted polymer was exhaustively esterified with methacrylic anhydride to obtain polyethylendimethacrylate-co-methacrylic acid linear chains. Then, as a proof of concept, an adequate amount of a very polar template like penicillin V was added in a hydro-organic mixture, and a thin layer of imprinted polymer was obtained by cross-linking the polymer linear chains. The binding behaviour of the imprinted and non-imprinted capillaries was evaluated in different separation conditions in order to assess the presence of template selectivity and molecular recognition effects. The experimental results clearly show that this innovative kind of imprinted material can be easily obtained in very polar polymerization environments and that it is characterized by enhanced molecular recognition properties in aqueous buffers and good selectivity towards the template and strictly related molecules.

  5. Removal of Toxic Mercury from Petroleum Oil by Newly Synthesized Molecularly-Imprinted Polymer

    Directory of Open Access Journals (Sweden)

    Nor Ain Shahera Khairi

    2015-05-01

    Full Text Available In recent years, molecularly-imprinted polymers (MIPs have attracted the attention of several researchers due to their capability for molecular recognition, easiness of preparation, stability and cost-effective production. By taking advantage of these facts, Hg(II imprinted and non-imprinted copolymers were prepared by polymerizing mercury nitrate stock solution (or without it with methacrylic acid (MAA, 2-hydroxyl ethyl methacrylate (HEMA, methanol and ethylene glycol dimethacrylate (EGDMA as the monomer, co-monomer solvent (porogen and cross-linker, respectively. Thus, the formed Hg(II imprinted polymer was characterized by using Fourier transform infrared spectroscopy (FTIR, field emission scanning electron microscopy (FESEM, Brunauer, Emmett and Teller (BET and thermal gravimetric analysis (TGA. The separation and preconcentration characteristics of Hg(II imprinted polymer were investigated by solid phase extraction (SPE procedures, and an optimal pH of 7 was investigated as ideal. The specific surface area of the Hg(II imprinted polymer was found to be 19.45 m2/g with a size range from 100 to 140 µm in diameter. The maximum adsorption capacity was observed to be 1.11 mg/g of Hg(II imprinted beads with 87.54% removal of Hg(II ions within the first 5 min. The results of the study therefore confirm that the Hg(II imprinted polymer can be used multiple times without significantly losing its adsorption capacity.

  6. Characterization of molecularly imprinted polymers using a new polar solvent titration method.

    Science.gov (United States)

    Song, Di; Zhang, Yagang; Geer, Michael F; Shimizu, Ken D

    2014-07-01

    A new method of characterizing molecularly imprinted polymers (MIPs) was developed and tested, which provides a more accurate means of identifying and measuring the molecular imprinting effect. In the new polar solvent titration method, a series of imprinted and non-imprinted polymers were prepared in solutions containing increasing concentrations of a polar solvent. The polar solvent additives systematically disrupted the templation and monomer aggregation processes in the prepolymerization solutions, and the extent of disruption was captured by the polymerization process. The changes in binding capacity within each series of polymers were measured, providing a quantitative assessment of the templation and monomer aggregation processes in the imprinted and non-imprinted polymers. The new method was tested using three different diphenyl phosphate imprinted polymers made using three different urea functional monomers. Each monomer had varying efficiencies of templation and monomer aggregation. The new MIP characterization method was found to have several advantages. To independently verify the new characterization method, the MIPs were also characterized using traditional binding isotherm analyses. The two methods appeared to give consistent conclusions. First, the polar solvent titration method is less susceptible to false positives in identifying the imprinting effect. Second, the method is able to differentiate and quantify changes in binding capacity, as measured at a fixed guest and polymer concentration, arising from templation or monomer aggregation processes in the prepolymerization solution. Third, the method was also easy to carry out, taking advantage of the ease of preparing MIPs.

  7. EFFECTS OF PRIMARY IMPRINTING ON THE SUBSEQUENT DEVELOPMENT OF SECONDARY FILIAL ATTACHMENTS IN THE CHICK

    NARCIS (Netherlands)

    DEVOS, GJ; VANKAMPEN, HS

    1993-01-01

    This study reinvestigates the effects of primary imprinting of chicks with either a naturalistic stimulus or an artificial object on subsequent imprinting with artificial objects. Initial experience with a live chick (group C) or a yellow cylinder (group Y) had differential effects on the developmen

  8. Polycarbonate as an Elasto-Plastic Material Model for Simulation of the Microstructure Hot Imprint Process

    Directory of Open Access Journals (Sweden)

    Rokas Šakalys

    2013-08-01

    Full Text Available The thermal imprint process of polymer micro-patterning is widely applied in areas such as manufacturing of optical parts, solar energy, bio-mechanical devices and chemical chips. Polycarbonate (PC, as an amorphous polymer, is often used in thermoforming processes because of its good replication characteristics. In order to obtain replicas of the best quality, the imprint parameters (e.g., pressure, temperature, time, etc. must be determined. Therefore finite element model of the hot imprint process of lamellar periodical microstructure into PC has been created using COMSOL Multiphysics. The mathematical model of the hot imprint process includes three steps: heating, imprinting and demolding. The material properties of amorphous PC strongly depend on the imprint temperature and loading pressure. Polycarbonate was modelled as an elasto-plastic material, since it was analyzed below the glass transition temperature. The hot imprint model was solved using the heat transfer and the solid stress-strain application modes with thermal contact problem between the mold and polycarbonate. It was used for the evaluation of temperature and stress distributions in the polycarbonate during the hot imprint process. The quality of the replica, by means of lands filling ratio, was determined as well.

  9. Polycarbonate as an elasto-plastic material model for simulation of the microstructure hot imprint process.

    Science.gov (United States)

    Narijauskaitė, Birutė; Palevičius, Arvydas; Gaidys, Rimvydas; Janušas, Giedrius; Sakalys, Rokas

    2013-08-22

    The thermal imprint process of polymer micro-patterning is widely applied in areas such as manufacturing of optical parts, solar energy, bio-mechanical devices and chemical chips. Polycarbonate (PC), as an amorphous polymer, is often used in thermoforming processes because of its good replication characteristics. In order to obtain replicas of the best quality, the imprint parameters (e.g., pressure, temperature, time, etc.) must be determined. Therefore finite element model of the hot imprint process of lamellar periodical microstructure into PC has been created using COMSOL Multiphysics. The mathematical model of the hot imprint process includes three steps: heating, imprinting and demolding. The material properties of amorphous PC strongly depend on the imprint temperature and loading pressure. Polycarbonate was modelled as an elasto-plastic material, since it was analyzed below the glass transition temperature. The hot imprint model was solved using the heat transfer and the solid stress-strain application modes with thermal contact problem between the mold and polycarbonate. It was used for the evaluation of temperature and stress distributions in the polycarbonate during the hot imprint process. The quality of the replica, by means of lands filling ratio, was determined as well.

  10. Preparation and evaluation of spore-specific affinity- augmented bio-imprinted beads

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Scott D.; Mong, Gary M.; Ozanich, Rich M.; Mclean, Jeffrey S.; Goodwin, Shannon M.; Valentine, Nancy B.; Fredrickson, Jim K.

    2006-09-01

    The procedures previously described for imprinting bead surfaces with bacteria were applied to create novel affinity-augmented bacterial spore-imprinted beads. The imprinted beads are intended as a front-end spore capture/concentration stage of an integrated biological detection system. Our approach involves embedding bead surfaces with Bacillus thuringiensis kurstaki (Bt) spores (as a surrogate for Bacillus anthracis) during synthesis. Subsequent steps involved lithographic deactivation using a perfluoroether, spore removal to create imprint sites, and coating imprints with the lectin, concanavalin A, to provide general affinity. The synthesis of the intended material with the desired imprints was verified by scanning electron and confocal laser-scanning microscopy. The material was evaluated using spore-binding assays with either Bt or Bacillus subtilis (Bs) spores. The binding assays indicated strong spore-binding capability and a robust imprinting effect that accounted for 25 percent additional binding over nonimprinted controls. The binding assay results also indicated that further refinement of the surface deactivation procedure would enhance the performance of the imprinted substrate.

  11. Protein imprinting and recognition via forming nanofilms on microbeads surfaces in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yan, E-mail: yanlu2001@sohu.com [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007 (China); Yan Changling [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007 (China); Wang Xuejing [Chemistry and Chemical Engineer School, Henna Institute of Science and Technology, Xinxiang 453003 (China); Wang Gongke [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007 (China)

    2009-12-15

    In this paler, we present a technique of forming nanofilms of poly-3-aminophenylboronic acid (pAPBA) on the surfaces of polystyrene (PS) microbeads for proteins (papain and trypsin) in aqueous. Papain was chosen as a model to study the feasibility of the technique and trypsin as an extension. Obtained core-shell microbeads were characterized using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and BET methods. The results show that pAPBA formed nanofilms (60-100 nm in thickness) on the surfaces of PS microbeads. The specific surface area of the papain-imprinted beads was about 180 m{sup 2} g{sup -1} and its pore size was 31 nm. These imprinted microbeads exhibit high recognition specificity and fast mass transfer kinetics. The specificity of these imprinted beads mainly originates from the spatial effect of imprinted sites. Because the protein-imprinted sites were located at, or close to, the surface, the imprinted beads have good site accessibility toward the template molecules. The facility of the imprinting protocol and the high recognition properties of imprinted microbeads make the approach an attractive solution to problems in the field of biotechnology.

  12. MEMORY FOR THE SPATIAL POSITION OF AN IMPRINTING OBJECT IN JUNGLEFOWL CHICKS

    NARCIS (Netherlands)

    VANKAMPEN, HS; DEVOS, GJ

    1992-01-01

    The characteristics of memory for the position of an imprinting object were investigated in junglefowl chicks (Gallus gallus spadiceus). Subjects were exposed individually and continuously to an imprinting object located in one of the two back quadrants of their home cage ('training quadrant'). Posi

  13. Epigenetics: imprinting in plants and mammals--the same but different?

    Science.gov (United States)

    Scott, Rod J; Spielman, Melissa

    2004-03-09

    Plants and animals both exhibit parental imprinting, but do they control it the same way? Recent studies show that in Arabidopsis, as in mammals, imprinted alleles are subject to DNA methylation--but, surprisingly, the default state is silence rather than activity.

  14. Imprinting of Phenylalanine ethyl ester in cyclodextrin polymers in aqueous solution

    DEFF Research Database (Denmark)

    Detcheva, Anna Hr.; Yu, Donghong; Larsen, Kim Lambertsen

    During the last decades there has been a wide interest of developing molecularly imprinted polymers, which selectively can recognize small molecules. Cyclodextrins offer relatively strong binding site of a wide range of small molecules in water and molecular imprinted polymers of these have previ...

  15. Rapid Prototyping of Chemical Microsensors Based on Molecularly Imprinted Polymers Synthesized by Two-Photon Stereolithography.

    Science.gov (United States)

    Gomez, Laura Piedad Chia; Spangenberg, Arnaud; Ton, Xuan-Anh; Fuchs, Yannick; Bokeloh, Frank; Malval, Jean-Pierre; Tse Sum Bui, Bernadette; Thuau, Damien; Ayela, Cédric; Haupt, Karsten; Soppera, Olivier

    2016-07-01

    Two-photon stereolithography is used for rapid prototyping of submicrometre molecularly imprinted polymer-based 3D structures. The structures are evaluated as chemical sensing elements and their specific recognition properties for target molecules are confirmed. The 3D design capability is exploited and highlighted through the fabrication of an all-organic molecularly imprinted polymeric microelectromechanical sensor.

  16. Fibers coated with molecularly imprinted polymers for solid-phase microextraction

    NARCIS (Netherlands)

    Koster, E.H M; Crescenzi, C; den Hoedt, W; Ensing, K; de Jong, G.J.

    2001-01-01

    The simplicity and flexibility of solid-phase microextraction have been combined with the selectivity of molecularly imprinted polymers (MIPs), Silica fibers were coated reproducible with a 75-mum layer of methacrylate polymer either nonimprinted or imprinted with clenbuterol to compare their extrac

  17. Genomic Imprinting——The Story of the Other Half and the Conflicts of Silencing%基因组印记研究进展

    Institute of Scientific and Technical Information of China (English)

    Anjana Munshi; Shanti Duvvuri

    2007-01-01

    基因组印记是由于父源或母源的等位基因受到"标记"而发生的不符合孟德尔遗传定律的特殊遗传现象.父源或母源的等位基因通过某种特异的基因修饰机制,如DNA甲基化,非编码RNA的调节作用和组蛋白修饰等,抑制另一拷贝的表达.哺乳动物中的基因印记影响着其生长发育,正常印记模式的改变在临床上会引起许多疾病.文章总结了自印记现象被发现后二十几年来的研究进展,包括印记的发生机制、发生途径、进化方式和起源理论.目前对基因印记的了解还不完全,后基因组技术的发展也许能够促进对其分子机制的进一步揭示.%Genomic imprinting is an epigenetic mechanism that produces functional differences between the paternal and maternal genomes and plays an essential role in mammalian development and growth. There are a number of genes in our genomes that are subject to genomic imprinting where one parent's copy of the gene is expressed while the other is silent. Silencing of one allele predetermines that any function ascribed to that gene are now dependant on the single active copy. Possession of only a single active allele can lead to deleterious health consequences in humans. If imprinted genes are crucial in mammalian development, one would also expect mutations in these genes to cause diseases. Since imprinting is an epigenetic mechanism, mistakes in maintaining epigenetic mark also cause imprinting disorders. Here we in this review focus on the current understanding of this unique genetic mechanism more than two decades after the first description of the imprinting phenomenon was given by McGrath and Solter. Although the possible molecular mechanisms by which imprinting is imposed and maintained are being identified, we have a long way to go in understanding the molecular mechanisms that regulate the expression of these oddly behaving genes, the function of imprinting and the evolution. Post genomic

  18. ZFP57 maintains the parent-of-origin-specific expression of the imprinted genes and differentially affects non-imprinted targets in mouse embryonic stem cells

    DEFF Research Database (Denmark)

    Riso, Vincenzo; Cammisa, Marco; Kukreja, Harpreet

    2016-01-01

    ZFP57 is necessary for maintaining repressive epigenetic modifications at Imprinting control regions (ICRs). In mouse embryonic stem cells (ESCs), ZFP57 binds ICRs (ICRBS) and many other loci (non-ICRBS). To address the role of ZFP57 on all its target sites, we performed high-throughput and multi......-locus analyses of inbred and hybrid mouse ESC lines carrying different gene knockouts. By using an allele-specific RNA-seq approach, we demonstrate that ZFP57 loss results in derepression of the imprinted allele of multiple genes in the imprinted clusters. We also find marked epigenetic differences between ICRBS...... the imprinted expression over long distances. At non-ICRBS, ZFP57 inactivation results in acquisition of epigenetic features that are characteristic of poised enhancers, suggesting that another function of ZFP57 in early embryogenesis is to repress cis-acting regulatory elements whose activity is not yet...

  19. Effectively designed molecularly imprinted polymers for selective extraction of glabridin from Glycyrrhiza glabra L. residues by screening the library of non-imprinted polymers.

    Science.gov (United States)

    Chen, Lingxiao; Ji, Wenhua; Duan, Wenjuan; Wang, Xiao; Gao, Qianshan; Geng, Yanling; Huang, Luqi

    2014-08-15

    Molecularly imprinted polymers (MIPs) with high selectivity and affinity to glabridin were designed based on the screening results of the library of non-imprinted polymers (NIPs). The NIP library contained 48 polymers that were polymerized with the combinations of different functional monomers, cross-linkers, and porogenic solvents. The distribution coefficient (k) values were used to estimate the affinity of NIPs to glabridin. The corresponding MIPs of the best three NIPs were prepared. After evaluating the imprinting effects and selectivity of the three MIPs, the performance of the best MIP as solid phase extraction sorbent was investigated. Glabridin with percent recovery of 83 was obtained from the extract of Glycyrrhiza glabra L. (G. glabra L.) residues by molecularly imprinted solid phase extraction (MISPE). Thus, this material can be successfully used for the extraction and purification of glabridin from G. glabra L. residues.

  20. Genome Defense Mechanisms in Neurospora and Associated Specialized Proteins

    Directory of Open Access Journals (Sweden)

    Ranjan Tamuli

    2010-06-01

    Full Text Available Neurospora crassa, the filamentous fungus possesses widest array of genome defense mechanisms known to any eukaryotic organism, including a process called repeat-induced point mutation (RIP. RIP is a genome defense mechanism that hypermutates repetitive DNA sequences; analogous to genomic imprinting in mammals. As an impact of RIP, Neurospora possesses many fewer genes in multigene families than expected. A DNA methyltransferase homologue, RID was shown to be essential for RIP. Recently, a variant catalytic subunit of translesion DNA polymerase zeta (Pol zeta has been found to be essential for dominant RIP suppressor phenotype. Meiotic silencing and quelling are two other genome defense mechanisms in Neurospora, and proteins required for these two processes have been identified through genetic screens.

  1. Progress in research on imprinted gene associated with male infertility%男性不育相关印记基因研究进展

    Institute of Scientific and Technical Information of China (English)

    王文静; 王瑞雪; 刘睿智

    2015-01-01

    The connection between male infertility and abnormal methylation of imprinted genes has attracted much attention.Some imprinted genes, e.g., H19, MEG3, MEST and SNRPN, are known to be related with male infertility.Abnormal imprinted information may influence sperm concentration, motility and morphology, but the mechanism is still unclear.Sperm genomic imprinting reconstruction and erase respectively occur at the time of spermatogenesis and before embryo transfer.Many studies have shown that the probability of imprinting disorder syndrome of offspring born through assisted reproductive technology(ART) was significantly higher, leading to the worry about the safety of ART and speculation that the operation and in vitro environment may affect sperm imprinted information, which in turn may lead to imprinting diseases in the offspring.However, above connection still lacks convincing evidence.This paper has conducted a literature review of recent literature and explored the impact of abnormal methylation of imprinted genes on male fertility and the offspring.%随着对男性不育病因机制的深入研究,男性不育与印记基因异常甲基化的联系引起了广泛关注.H19、MEG3、MEST、SNRPN基因是与男性不育相关的印记基因,异常的印记信息可能会对精液质量(如精子浓度、活力和形态)产生影响,但其机制目前尚不清楚.精子基因印记重建和擦除分别出现在精子发生过程和胚胎移植前,加之越来越多研究显示通过辅助生殖技术出生子代患印记紊乱综合征的几率明显高于自然生育的子代,引发了人们对于辅助生殖技术安全性的担忧,并推测该技术操作过程及体外环境可能会对精子印记信息产生影响,继而导致子代患印记疾病,但这种推测尚缺乏有力的证据.本文系统地阐述了印记基因异常对男性生育能力的影响以及其对子代可能衍生的影响,为男性不育病因的表观遗传学机制研究提供帮助.

  2. Enhanced surface patterning of chalcogenide glass via imprinting process using a buffer layer

    Science.gov (United States)

    Jin, Byeong Kyou; Choi, Duk-Yong; Chung, Woon Jin; Choi, Yong Gyu

    2017-09-01

    In an effort to enhance transcriptability of quasi-three-dimensional patterns present in silicon stamp onto the surface of 'bulk' chalcogenide glass, a buffer layer was introduced during the replication process via imprinting. Dissimilar patterns with diverse depths along the surface normal direction were imprinted with or without the buffer layer, and the resulting patterns on the glass surface were compared with regard to the transcription quality in both the lateral and vertical directions. After assessing the processing conditions appropriate for imprinting bulk As2S3 glass especially in terms of temperature and duration, candidate materials suitable for the buffer layer were screened: Commercially available polydimethylsiloxane was then chosen, and impact of this buffer layer was elucidated. The imprinted patterns turned out to become more uniform over large surface areas when the buffer layer was inserted. This finding confirmed that the use of buffer layer conspicuously enhanced the transcriptability of imprinting process for bulk chalcogenide glass.

  3. Molecular receptors in metal oxide sol-gel materials prepared via molecular imprinting

    Science.gov (United States)

    Sasaki, Darryl Y.; Brinker, C. Jeffrey; Ashley, Carol S.; Daitch, Charles E.; Shea, Kenneth J.; Rush, Daniel J.

    2000-01-01

    A method is provided for molecularly imprinting the surface of a sol-gel material, by forming a solution comprised of a sol-gel material, a solvent, an imprinting molecule, and a functionalizing siloxane monomer of the form Si(OR).sub.3-n X.sub.n, wherein n is an integer between zero and three and X is a functional group capable of reacting with the imprinting molecule, evaporating the solvent, and removing the imprinting molecule to form the molecularly imprinted metal oxide sol-gel material. The use of metal oxide sol-gels allows the material porosity, pore size, density, surface area, hardness, electrostatic charge, polarity, optical density, and surface hydrophobicity to be tailored and be employed as sensors and in catalytic and separations operations.

  4. GABA{sub A} receptor beta 3 subunit gene is possibly paternally imprinted in humans

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-02-15

    As the gene for GABA{sub A} receptor beta 3 subunit (GABRB3) is encompassed by a small molecular deletion in chromosome 15q11-q13, which is the critical region for Angelman syndrome(AS), the GABRB3 gene could be a candidate gene for AS. The abnormal phenotype of AS is manifested only when the deletion is inherited from the mother, not from the father. Therefore, a candidate gene for AS should be paternally imprinted. Although it was reported that the GABRB3 gene was expressed equally from either the maternal or paternal chromosome in mouse brain (i.e., not imprinted), it is well known that imprinting shows tissue specificity, and it remains to be determined if all genes imprinted in the mouse are also imprinted in humans. 4 refs., 1 fig.

  5. Synthesis and Characterization of Molecular Imprinting Polymer Microspheres of Piperine: Extraction of Piperine from Spiked Urine

    Science.gov (United States)

    Roland, Rachel Marcella

    2016-01-01

    Molecularly imprinted polymer (MIP) microspheres for Piperine were synthesized by precipitation polymerization with a noncovalent approach. In this research Piperine was used as a template, acrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, and 2,2′-azobisisobutyronitrile (AIBN) as an initiator and acetonitrile as a solvent. The imprinted and nonimprinted polymer particles were characterized by using Fourier transform infrared spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). The synthesized polymer particles were further evaluated for their rebinding efficiency by batch binding assay. The highly selected imprinted polymer for Piperine was MIP 3 with a composition (molar ratio) of 0.5 : 3 : 8, template : monomer : cross-linker, respectively. The MIP 3 exhibits highest binding capacity (84.94%) as compared to other imprinted and nonimprinted polymers. The extraction efficiency of highly selected imprinted polymer of Piperine from spiked urine was above 80%. PMID:28018704

  6. Advances in Surface Molecular Imprinting%表面分子印迹研究进展

    Institute of Scientific and Technical Information of China (English)

    仰云峰; 车爱馥; 吴健; 徐志康

    2007-01-01

      为了拓展分子印迹聚合物(Molecularly Imprinted Polymers, MIP)的应用领域,表面分子印迹作为一种新的方法,受到了极大的关注。本文首先分析了MIP传统制备方法存在的问题;然后依据印迹位点所处位置的不同,分类综述了表面分子印迹的各种方法。%  To extend molecularly imprinted polymer(MIP) to new application areas, surface molecular imprinting as a novel approach has received significant attention. Problems existing in the conventional method of synthesis of MIP are firstly estimated in this review. A variety of different strategies for surface imprinting are discussed according to imprinted sites locating at different regions.

  7. Protein imprinted polymer using acryloyl-β-cyclodextrin and acrylamide as monomers

    Science.gov (United States)

    Zhang, Wei; Qin, Lei; Chen, Run-Run; He, Xi-Wen; Li, Wen-You; Zhang, Yu-Kui

    2010-02-01

    A novel protein imprinted polymer was prepared using acryloyl-β-cyclodextrin (β-CD) and acrylamide as monomers on the surface of silica gel. The bovine hemoglobin was used as template and β-CD was allowed to self-assemble with the template protein through hydrogen bonding and hydrophobic interaction. Polymerization was carried out in the presence of acrylamide as an assistant monomer, which resulted in a novel protein imprinted polymer. After removing the template, imprinted cavities with the shape and spatial distribution of functional groups were formed. Bovine serum albumin (BSA) cytochrome c (Cyt) and lysozyme (Lyz) were employed as non-template proteins to test the imprinting effect and the specific binding of bovine hemoglobin to the polymer. The results of the adsorption experiments indicated that such protein imprinted polymer, which was synthesized with β-CD and acrylamide as monomers, could selectively recognize the template protein.

  8. Magnetic molecularly imprinted polydopamine nanolayer on multiwalled carbon nanotubes surface for protein capture.

    Science.gov (United States)

    Yin, Yuli; Yan, Liang; Zhang, Zhaohui; Wang, Jing

    2015-11-01

    A novel, facile and low cost process for imprinting protein on the surface of magnetic multiwalled carbon nanotubes (MMWNTs) was developed using human serum albumin (HSA) as the template and dopamine as the functional monomer. The magnetic imprinted polymers were characterized with transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier-transform infrared spectrometry (FT-IR), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA) in detail. The maximum adsorption capacity of the magnetic imprinted polymers toward HSA was 66.23 mg g(-1) and it took 20 min to achieve the adsorption equilibrium. The magnetic imprinted polymers exhibited the specific selective adsorption toward HSA. Coupled with high performance liquid chromatography (HPLC) analysis, the magnetic imprinted polymers were used to solid-phase extract and detect HSA in urine samples successfully with the recoveries of 91.95-97.8%.

  9. Imprinted Polymeric Film-Based Sensor for the Detection of Dopamine Using Cyclic Voltammetry

    Institute of Scientific and Technical Information of China (English)

    郭洪声; 何锡文; 李一峻

    2003-01-01

    The imprinted polymeric film was synthesized on the glass-carbon electrodes dlrectly. The response to the template molecule-dopamine and other molecules with similar structure was measured by cyclic voltammetry. The response of dopamine on imprinted electrode was much higher than that of other molecules,because of the existing of micro-cavities in polymeric rdm fitting with the size and shape of dopamine in the imprinted polymer.Experimental results showed that dopamlne can be enriched by the imprinted film, therefore increasing the sensitivity of the sensor. The imprinted film could also efface the interference of ascorbic acid, indicating that dopamine can be determined with a large excess of ascorbic acid.

  10. Imprinting Analysis of the Porcine MEST Gene in 75 and 90 Day Placentas and Prenatal Tissues

    Institute of Scientific and Technical Information of China (English)

    Chenchang XU; Lijie SU; Quanyong ZHOU; Changchun LI; Shuhong ZHAO

    2007-01-01

    Imprinted genes play important roles in mammalian growth, development and behavior. Mouse mesoderm-specific transcript (MEST) has been identified as an imprinted gene and mapped to an imprinted region of mouse chromosome 6 (MMU6). It plays essential roles in embryonic and placental growth, and it is required for maternal behavior in adult female mouse. Here, we isolated the porcine MEST gene and detected a single nucleotide polymorphism in the 3'-untranslated region. The RsaI polymorphism was used to investigate the allele frequencies in different pig breeds and the imprinting status in prenatal porcine tissues.Allele frequencies were significantly different between the native Chinese and Landrace breeds, except that most of the native Yushan pigs (21/26) are heterozygous at this locus. The results indicate that MEST was imprinted in placentas on days 75 and 90 of gestation as well as in the 75 d fetal heart, muscle, kidney, lung and liver.

  11. [Application of molecularly imprinted technology for separation of PGG from Guizhi Fuling capsule].

    Science.gov (United States)

    Song, Ya-ling; Wang, Xue-jing; Ni, Fu-yong; Gu, Rui; Zhao, Yi-wu; Huang, Wen-zhe; Wang, Zhen-zhong; Xu, Xiao-jie; Xiao, Wei

    2015-03-01

    1,2,3,4,6-penta-O-galloyl-D-glucose (PGG) is one of the main active compounds of Guizhi Fuling capsule. Molecularly imprinted polymers (MIP) have high affinity toward template molecules synthesized by molecularly imprinted technology for its specific combined sites, which can overcome the shortcoming of traditional separation methods, such as complex operation, low efficiency, using large quantity of solvent and environmental pollution. In this paper, surface molecularly imprinted polymer (SMIP) was prepared by surface imprinting with PGG as the template molecule. Its adsorption capacity was measured by the scatchard equation. The separation of PGG from Guizhi Fuling capsule at preparatived scale was achieved with molecularly imprinted polymer as stationary phase and the purity was 90.2% by HPLC. This method can be used to prepare PGG from Guizhi Fuling capsule with large capacity and is easy to operate. It provides a new method for efficient separation and purification for other natural products.

  12. Molecularly Imprinted Polymers: Thermodynamic and Kinetic Considerations on the Specific Sorption and Molecular Recognition

    Directory of Open Access Journals (Sweden)

    Kejun Tong

    2008-04-01

    Full Text Available This article presents a work aiming at thermodynamically and kinetically interpreting the specific sorption and recognition by a molecularly imprinted polymer. Using Boc-L-Phe-OH as a template, the imprinted material was prepared. The result indicates that the prepared polymer can well discriminate the imprint species from its analogue (Boc-D-Phe-OH, so as to adsorb more for the former but less for the latter. Kinetic analysis indicates that this specific sorption, in nature, can be a result of a preferential promotion. The imprint within the polymer causes a larger adsorption rate for the template than for the analogue. Thermodynamic study also implies that the molecular induction from the specific imprint to the template is larger than to the analogue, which thus makes the polymer capable of preferentially alluring the template to bind.

  13. Expression,Imprinting,and Evolution of Rice Homologs of the Polycomb Group Genes

    Institute of Scientific and Technical Information of China (English)

    Ming Luo; Damien Platten; Abed Chaudhury; W.J.Peacock; Elizabeth S.Dennis

    2009-01-01

    Polycomb group proteins (PcG) play important roles in epigenetic regulation of gene expression.Some core PcG proteins,such as Enhancer of Zeste (E(z)),Suppressor of Zeste (12) (Su(z)12),and Extra Sex Combs (ESC),are conserved in plants.The rice genome contains two E(z)-like genes,OsiEZ1 and OsCLF,two homologs of Su(z)12,OsEMF2a and OsEMF2b,and two ESC-like genes,OsFIE1 and OsFIE2.OsFIE1 is expressed only in endosperm;the maternal copy is expressed while the paternal copy is not active.Other rice PcG genes are expressed in a wide range of tissues and are not imprinted in the endosperm.The two E(z)-like genes appear to have duplicated before the separation of the dicots and monocots;the two homologs of Su(z)12 possibly duplicated during the evolution of the Gramineae and the two ESC-like genes are likely to have duplicated in the ancestor of the grasses.No homologs of the Arabidopsis seed-expressed PeG genes MEA and FIS2 were identified in the rice genome.We have isolated T-DNA insertion lines in the rice homologs of three PcG genes.There is no autonomous endosperm development in these T-DNA insertion lines.One line with a T-DNA insertion in OsEMF2b displays pleiotropic phenotypes including altered flowering time and abnormal flower organs,suggesting important roles in rice development for this gene.

  14. Chiral imprinting of diblock copolymer single-chain particles.

    Science.gov (United States)

    Njikang, Gabriel; Liu, Guojun; Hong, Liangzhi

    2011-06-07

    This Article reports the molecular imprinting of polymer single-chain particles that have a radius ∼3.7 nm. For this, the template L-phenylalanine anilide or L-ΦAA and a diblock copolymer PtBA-b-P(CEMA-r-CA) were used. Here, PtBA denotes poly(tert-butyl acrylate), and P(CEMA-r-CA) denotes a random block consisting of cinnamoyloxyethyl methacrylate (CEMA) and carboxyl-bearing (CA) units. In CHCl(3)/cyclohexane (CHX) with 64 vol % of CHX or at f(CHX) = 64%, a block-selective solvent for PtBA, PtBA-b-P(CEMA-r-CA) formed spherical micelles. The core consisted of the insoluble P(CEMA-r-CA) block and L-ΦAA, which complexed with the CA groups. Pumping slowly this micellar solution into stirred CHCl(3)/(CHX) at f(CHX) = 64% triggered micelle dissociation into single-chain micelles, which comprised presumably a solubilized PtBA tail and a collapsed P(CEMA-r-CA)/L-ΦAA head. Because the solvent reservoir was under constant UV irradiation, the photo-cross-linkable units in the P(CEMA-r-CA) head cross-linked, and the single-chain micelles were converted into cross-linked single-chain micelles or tadpoles. Synchronizing the micelle addition and photoreaction rates allowed the preparation, from this protocol, of essentially pure tadpoles at high final polymer concentrations. Imprinted tadpoles were procured after L-ΦAA was extracted from the tadpole heads. Under optimized conditions, the produced imprinted tadpoles had exceptionally high binding capacity and high selectivity for L-ΦAA. In addition, the rates of L-ΦAA release from and rebinding by the particles were high.

  15. DNA methylation imprinting errors in spermatogenic cells from maturation arrest azoospermic patients.

    Science.gov (United States)

    Marques, P I; Fernandes, S; Carvalho, F; Barros, A; Sousa, M; Marques, C J

    2017-03-10

    Imprinting errors have been described in spermatozoa from infertile patients with oligozoospermia and azoospermia. However, little is known about methylation of imprinted genes in other spermatogenic cells from azoospermic patients. Therefore, we aimed to evaluate the methylation status of single CpGs located in the differentially methylated regions (DMRs) of two imprinted genes, one paternally (H19) and one maternally (MEST) methylated, in primary spermatocytes of azoospermic patients presenting complete (MAc, n = 7) and incomplete (MAi, n = 8) maturation arrest, as well as in other spermatogenic cells from MAi patients that presented focus of complete spermatogenesis in some seminiferous tubules. We observed H19 imprinting errors in primary spermatocytes from one MAi patient and MEST imprinting errors in one MAi and two MAc patients. Additionally, H19 imprinting errors were observed in elongated spermatids/spermatozoa from one MAi patient. Nevertheless, no statistical differences were found for H19 and MEST global methylation levels (percentage of methylated and unmethylated CpGs, respectively) between patients with complete and incomplete MA and also between MA groups and a control group. These results provide further evidence that imprinting errors occur in spermatogenic cells from patients presenting impaired spermatogenesis, as we and others have previously described in ejaculated and testicular spermatozoa. As paternal imprinting errors can be transmitted to the embryo by the sperm cell, they can provide a possible explanation for poor embryo development and/or low pregnancy rates as correct expression of imprinted genes is crucial for embryo and placental development and function. Therefore, in cases with male factor infertility where unsuccessful in vitro fertilization (IVF) treatments are recurrent, analysis of imprinting marks in spermatozoa might be a useful diagnostic tool.

  16. Ultrafast imprinting of topologically protected magnetic textures via pulsed electrons

    Science.gov (United States)

    Schäffer, A. F.; Dürr, H. A.; Berakdar, J.

    2017-07-01

    Short electron pulses are demonstrated to trigger and control magnetic excitations, even at low electron current densities. We show that the tangential magnetic field surrounding a picosecond electron pulse can imprint topologically protected magnetic textures such as skyrmions in a sample with a residual Dzyaloshinskii-Moriya spin-orbital coupling. Characteristics of the created excitations such as the topological charge can be steered via the duration and the strength of the electron pulses. The study points to a possible way for a spatiotemporally controlled generation of skyrmionic excitations.

  17. Molecularly Imprinted Polymer Coated on Stainless Steel Fiber

    Institute of Scientific and Technical Information of China (English)

    Hu XiaoGang; Dai GuiMei; Huang JiaJing

    2009-01-01

    @@ With characteristics of specific selectivity,good chemical stability and easy preparation,molecularly imprinted polymer (MIP) has been used as the recognition materials m various fields ~([1,2]).Recently,the application of MIP in the sample pre-treatment techniques such as SPME was attractive ~([3,4]).For analysis of complicated samples,the interference matrix would be reduced obviously with the MIP-coated SPME fiber~([5-7]).Because MIPs were coated on the surface of silica fiber through chemical bonding,those fibers could be used for over 80 times without obvious losing of surface quality and extraction performance of MIP coatings.

  18. Molecularly imprinted polymers for on-line extraction techniques.

    Science.gov (United States)

    Moein, Mohammad M; Abdel-Rehim, Mohamed

    2015-01-01

    Recent years have seen an increasing interest in the use of molecularly imprinted polymers (MIPs) as a sorbent for different extraction methods and this is due to its high selectivity. The MIP is designed to show specificity for the analyte of interest. Moreover, MIPs show physical robustness, resistance to high temperatures and pressures, and stability in the presence of acids, bases and a wide range of organic solvents. In the present article, various novel sample preparation techniques which MIPs applied as sorbent and on-line connected with analytical instruments were highlighted and discussed. The future aspects of MIPs as well were described.

  19. Molecular imprinted magnetic nanoparticles for controlled delivery of mitomycin C.

    Science.gov (United States)

    Türkmen, Deniz; Bereli, Nilay; Çorman, M Emin; Shaikh, Huma; Akgöl, Sinan; Denizli, Adil

    2014-10-01

    Controlled drug delivery system is a technique which has considerable recent potential in the fields of pharmacy and medicine. Mitomycin C is commonly used drug in the treatment of superficial bladder and breast cancers. In the present study, mitomycin C-imprinted magnetic poly(hydroxyethyl methacrylate)-based nanoparticles (MIMNs) were prepared using surfactant free emulsion polymerization for controlled delivery of mitomycin C. The MIMNs were characterized by fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, electron spin resonance, and elemental analysis. The average particle diameter of MIMNs was about 200 nm.

  20. A nano-scale alignment method for imprint lithography

    Institute of Scientific and Technical Information of China (English)

    WANG Li; LU Bing-heng; DING Yu-cheng; QIU Zhi-hui; LIU Hong-zhong

    2006-01-01

    A novel nano-scale alignment technique based generated by two pairs of quadruple gratings on mold and wafer are optically projected onto two photo-detector arrays,alignment errors in the x and y directions.The experiment sensitive to relative displacement of the mold and wafer,and the alignment accuracy obtained in the x and y directions and in θare ±20 nm,±25 nm and ±1 μrad (3σ),respectively.They can meet the requirements of alignment accuracy for submicron imprint lithography.