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Sample records for constant-domain ch1 exon

  1. The first constant-domain (CH1) exon of human IGHG2 is polymorphic and in strong linkage disequilibrium with the CH2 exon polymorphism encoding the G2m(n+) allotype in Caucasians

    DEFF Research Database (Denmark)

    Hougs, L; Svejgaard, A; Barington, T

    2001-01-01

    Here we describe a hitherto unknown proline/threonine polymorphism at residue 72 of the human IgG2 CH1 domain (EU numbering 189) and show that it is linked to the known valine/methionine polymorphism at residue 52 of CH2 (EU numbering 282) defining the G2m(n+)/G2m(n-) allotypes. We sequenced...

  2. Constant domain-regulated antibody catalysis.

    Science.gov (United States)

    Sapparapu, Gopal; Planque, Stephanie; Mitsuda, Yukie; McLean, Gary; Nishiyama, Yasuhiro; Paul, Sudhir

    2012-10-19

    Some antibodies contain variable (V) domain catalytic sites. We report the superior amide and peptide bond-hydrolyzing activity of the same heavy and light chain V domains expressed in the IgM constant domain scaffold compared with the IgG scaffold. The superior catalytic activity of recombinant IgM was evident using two substrates, a small model peptide that is hydrolyzed without involvement of high affinity epitope binding, and HIV gp120, which is recognized specifically by noncovalent means prior to the hydrolytic reaction. The catalytic activity was inhibited by an electrophilic phosphonate diester, consistent with a nucleophilic catalytic mechanism. All 13 monoclonal IgMs tested displayed robust hydrolytic activities varying over a 91-fold range, consistent with expression of the catalytic functions at distinct levels by different V domains. The catalytic activity of polyclonal IgM was superior to polyclonal IgG from the same sera, indicating that on average IgMs express the catalytic function at levels greater than IgGs. The findings indicate a favorable effect of the remote IgM constant domain scaffold on the integrity of the V-domain catalytic site and provide a structural basis for conceiving antibody catalysis as a first line immune function expressed at high levels prior to development of mature IgG class antibodies.

  3. Full Genome Sequence of Giant Panda Rotavirus Strain CH-1

    Science.gov (United States)

    Guo, Ling; Yang, Shaolin; Wang, Chengdong; Chen, Shijie; Yang, Xiaonong; Hou, Rong; Quan, Zifang; Hao, Zhongxiang

    2013-01-01

    We report here the complete genomic sequence of the giant panda rotavirus strain CH-1. This work is the first to document the complete genomic sequence (segments 1 to 11) of the CH-1 strain, which offers an effective platform for providing authentic research experiences to novice scientists. PMID:23469354

  4. Dual Constant Domain-Fab: A novel strategy to improve half-life and potency of a Met therapeutic antibody.

    Science.gov (United States)

    Cignetto, Simona; Modica, Chiara; Chiriaco, Cristina; Fontani, Lara; Milla, Paola; Michieli, Paolo; Comoglio, Paolo M; Vigna, Elisa

    2016-06-01

    The kinase receptor encoded by the Met oncogene is a sensible target for cancer therapy. The chimeric monovalent Fab fragment of the DN30 monoclonal antibody (MvDN30) has an odd mechanism of action, based on cell surface removal of Met via activation of specific plasma membrane proteases. However, the short half-life of the Fab, due to its low molecular weight, is a severe limitation for the deployment in therapy. This issue was addressed by increasing the Fab molecular weight above the glomerular filtration threshold through the duplication of the constant domains, in tandem (DCD-1) or reciprocally swapped (DCD-2). The two newly engineered molecules showed biochemical properties comparable to the original MvDN30 in vitro, acting as full Met antagonists, impairing Met phosphorylation and activation of downstream signaling pathways. As a consequence, Met-mediated biological responses were inhibited, including anchorage-dependent and -independent cell growth. In vivo DCD-1 and DCD-2 showed a pharmacokinetic profile significantly improved over the original MvDN30, doubling the circulating half-life and reducing the clearance. In pre-clinical models of cancer, generated by injection of tumor cells or implant of patient-derived samples, systemic administration of the engineered molecules inhibited the growth of Met-addicted tumors.

  5. Data of evolutionary structure change: 1CH1A-5MBAA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1CH1A-5MBAA 1CH1 5MBA A A MVLSEGEWQLVLHVWAKVEADVAGHGQDILIRLFKSHPE...244 ALA CA 195 GLU CA 242 LEU CA 314 5MBA... A 5MBAA NNAANAGKMSA...2670898 2.5844500064849854 1 5MBA... A 5MBAA

  6. Data of evolutionary structure change: 1CH1A-3MBAA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1CH1A-3MBAA 1CH1 3MBA A A MVLSEGEWQLVLHVWAKVEADVAGHGQDILIRLFKSHPE...4 ALA CA 195 GLU CA 242 LEU CA 314 3MBA... A 3MBAA NNAANAGKMSAML...12298584 2.589318037033081 1 3MBA... A 3MBAA

  7. Evolutionary history of exon shuffling.

    Science.gov (United States)

    França, Gustavo S; Cancherini, Douglas V; de Souza, Sandro J

    2012-06-01

    Exon shuffling has been characterized as one of the major evolutionary forces shaping both the genome and the proteome of eukaryotes. This mechanism was particularly important in the creation of multidomain proteins during animal evolution, bringing a number of functional genetic novelties. Here, genome information from a variety of eukaryotic species was used to address several issues related to the evolutionary history of exon shuffling. By comparing all protein sequences within each species, we were able to characterize exon shuffling signatures throughout metazoans. Intron phase (the position of the intron regarding the codon) and exon symmetry (the pattern of flanking introns for a given exon or block of adjacent exons) were features used to evaluate exon shuffling. We confirmed previous observations that exon shuffling mediated by phase 1 introns (1-1 exon shuffling) is the predominant kind in multicellular animals. Evidence is provided that such pattern was achieved since the early steps of animal evolution, supported by a detectable presence of 1-1 shuffling units in Trichoplax adhaerens and a considerable prevalence of them in Nematostella vectensis. In contrast, Monosiga brevicollis, one of the closest relatives of metazoans, and Arabidopsis thaliana, showed no evidence of 1-1 exon or domain shuffling above what it would be expected by chance. Instead, exon shuffling events are less abundant and predominantly mediated by phase 0 introns (0-0 exon shuffling) in those non-metazoan species. Moreover, an intermediate pattern of 1-1 and 0-0 exon shuffling was observed for the placozoan T. adhaerens, a primitive animal. Finally, characterization of flanking intron phases around domain borders allowed us to identify a common set of symmetric 1-1 domains that have been shuffled throughout the metazoan lineage.

  8. EasyExonPrimer: automated primer design for exon sequences.

    Science.gov (United States)

    Wu, Xiaolin; Munroe, David J

    2006-01-01

    EasyExonPrimer is a web-based software that automates the design of PCR primers to amplify exon sequences from genomic DNA. EasyExonPrimer is written in Perl and uses Primer3 to design PCR primers based on the genome builds and annotation databases available at the University of California, Santa Cruz (UCSC) Genome Browser database (http://genome.ucsc.edu/). It masks repeats and known single nucleotide polymorphism (SNP) sites in the genome and designs standardised primers using optimised conditions. Users can input genes by RefSeq mRNA ID, gene name or keyword. The primer design is optimised for large-scale resequencing of exons. For exons larger than 1 kb, the user has the option of breaking the exon sequence down into overlapping smaller fragments. All primer pairs are then verified using the In-Silico PCR software to test for uniqueness in the genome. We have designed >1000 pairs of primers for 90 genes; 95% of the primer pairs successfully amplified exon sequences under standard PCR conditions without requiring further optimisation. EasyExonPrimer is available from http://129.43.22.27/~primer/. The source code is also available upon request. Xiaolin Wu (forestwu@mail.nih.gov).

  9. Isolation and characterization of promoter regions from Streptococcus gordonii CH1

    NARCIS (Netherlands)

    Vriesema, A.J.M.; Dankert, J.; Zaat, S.A.J.

    1999-01-01

    We aimed to identify transcription signal sequences from Streptococcus gordonii strain CH1 by random chromosomal cloning. Five genomic fragments from a Sau3A digest, which constitutively activated transcription of a promoterless spectinomycin resistance gene in this strain, were isolated and charact

  10. The rice field cyanobacteria Anabaena azotica and Anabaena sp. CH1 express vanadium-dependent nitrogenase

    NARCIS (Netherlands)

    Boison, G.; Steingen, C.; Stal, L.J.; Bothe, H.

    2006-01-01

    Anabaena azotica FACHB-118 and Anabaena sp. CH1, heterocystous cyanobacteria isolated from Chinese and Taiwanese rice fields, expressed vanadium-containing nitrogenase when under molybdenum deficiency. This is the second direct observation of an alternative nitrogenase in cyanobacteria. The vanadium

  11. Role of κ→λ light-chain constant-domain switch in the structure and functionality of A17 reactibody

    Energy Technology Data Exchange (ETDEWEB)

    Ponomarenko, Natalia [Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow 117871 (Russian Federation); Chatziefthimiou, Spyros D. [European Molecular Biology Laboratory, Hamburg Unit, c/o DESY, Notkestrasse 85, 22603 Hamburg (Germany); Kurkova, Inna; Mokrushina, Yuliana; Mokrushina, Yuliana; Stepanova, Anastasiya; Smirnov, Ivan; Avakyan, Marat; Bobik, Tatyana; Mamedov, Azad [Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow 117871 (Russian Federation); Mitkevich, Vladimir [Russian Academy of Sciences, Moscow 119991 (Russian Federation); Belogurov, Alexey Jr [Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow 117871 (Russian Federation); Institute of Gene Biology, Moscow 117334 (Russian Federation); Fedorova, Olga S. [Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Dubina, Michael [St Petersburg Academic University, St Petersburg 194021 (Russian Federation); Golovin, Andrey [Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Lamzin, Victor [European Molecular Biology Laboratory, Hamburg Unit, c/o DESY, Notkestrasse 85, 22603 Hamburg (Germany); Friboulet, Alain [Centre National de la Recherche Scientifique, 60205 Compiègne (France); Makarov, Alexander A. [Russian Academy of Sciences, Moscow 119991 (Russian Federation); Wilmanns, Matthias [European Molecular Biology Laboratory, Hamburg Unit, c/o DESY, Notkestrasse 85, 22603 Hamburg (Germany); Gabibov, Alexander, E-mail: gabibov@mx.ibch.ru [Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow 117871 (Russian Federation); Institute of Gene Biology, Moscow 117334 (Russian Federation); Lomonosov Moscow State University, Moscow 119991 (Russian Federation)

    2014-03-01

    Catalytic antibody variants with κ and λ light-chain constant domains show differences in their crystal structures which lead to subtle changes in catalytic efficiency and thermodynamic parameters as well as in their affinity for peptide substrates. The engineering of catalytic function in antibodies requires precise information on their structure. Here, results are presented that show how the antibody domain structure affects its functionality. The previously designed organophosphate-metabolizing reactibody A17 has been re-engineered by replacing its constant κ light chain by the λ chain (A17λ), and the X-ray structure of A17λ has been determined at 1.95 Å resolution. It was found that compared with A17κ the active centre of A17λ is displaced, stabilized and made more rigid owing to interdomain interactions involving the CDR loops from the V{sub L} and V{sub H} domains. These V{sub L}/V{sub H} domains also have lower mobility, as deduced from the atomic displacement parameters of the crystal structure. The antibody elbow angle is decreased to 126° compared with 138° in A17κ. These structural differences account for the subtle changes in catalytic efficiency and thermodynamic parameters determined with two organophosphate ligands, as well as in the affinity for peptide substrates selected from a combinatorial cyclic peptide library, between the A17κ and A17λ variants. The data presented will be of interest and relevance to researchers dealing with the design of antibodies with tailor-made functions.

  12. Proteins, exons and molecular evolution.

    Science.gov (United States)

    Holland, S K; Blake, C C

    1987-01-01

    The discovery of the eukaryotic gene structure has prompted research into the potential relationship between protein structure and function and the corresponding exon/intron patterns. The exon shuffling hypothesis put forward by Gilbert and Blake suggests the encodement of structural and functional protein elements by exons which can recombine to create novel proteins. This provides an explanation for the relatively rapid evolution of proteins from a few primordial molecules. As the number of gene and protein structures increases, evidence of exon shuffling is becoming more apparent and examples are presented both from modern multi-domain proteins and ancient proteins. Recent work into the chemical properties and catalytic functions of RNA have led to hypotheses based upon the early existence of RNA. These theories suggest that the split gene structure originated in the primordial soup as a result of random RNA synthesis. Stable regions of RNA, or exons, were utilised as primitive enzymes. In response to selective pressures for information storage, the activity was directly transferred from the RNA enzymes or ribozymes, to proteins. These short polypeptides fused together to create larger proteins with a wide range of functions. Recent research into RNA processing and exon size, discussed in this review, provides a clearer insight into the evolutionary development of the gene and protein structure.

  13. Utilization of the cyanobacteria Anabaena sp CH1 in biological carbon dioxide mitigation processes

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, C.L.; Lee, C.M.; Chen, P.C. [Hungkuang University, Taichung (Taiwan)

    2011-05-15

    Before switching totally to alternative fuel stage, CO{sub 2} mitigation process has considered a transitional strategy for combustion of fossil fuels inevitably. In comparison to other CO{sub 2} mitigation options, such as oceanic or geologic injection, the biological photosynthetic process would present a far superior and sustainable solution under both environmental and social considerations. The utilization of the cyanobacteria Anabaena sp. CH1 in carbon dioxide mitigation processes is analyzed in our research. It was found that an original developed photobioreactor with internal light source exhibits high light utilization. Anabaena sp. CH1 demonstrates excellent CO{sub 2} tolerance even at 15% CO{sub 2} level. This enables flue gas from power plant to be directly introduced to Anabaena sp. CH1 culture. Double light intensity and increased 47% CO{sub 2} bubble retention time could enhance CO{sub 2} removal efficiencies by 79% and 67%, respectively. A maximum CO{sub 2} fixation rate of 1.01 g CO{sub 2} L{sup -1} day{sup -1} was measured experimentally.

  14. Potentiated anti-microsporidial activity of Lactobacillus acidophilus CH1 bacteriocin using gold nanoparticles.

    Science.gov (United States)

    Mossallam, Shereen F; Amer, Eglal I; Diab, Radwa G

    2014-09-01

    Through increased awareness and improved diagnostics, microsporidiosis has now been identified in a broader range of human populations; however current therapies are inconsistently effective. Recently, probiotics were determined as means for the control of intestinal parasitic infections through their secretory products; bacteriocins. This is the first study on the effect of bacteriocin produced by Lactobacillus acidophilus CH1 bacteriocin, with or without gold nanoparticles (Au-NPs), against intestinal microsporidiosis in immunosuppressed mice. Fecal and intestinal spore loads, besides viability, extrusion and infectivity of spores from treated animals were assessed. Results showed that the anti-microsporidial effects of bacteriocin were significantly potent. This efficiency was further potentiated upon conjugating bacteriocins with Au-NPs, as it induced a strikingly sustained reduction in fecal spore shedding after cessation of therapy by 1 week (94.26%). Furthermore, reduction in intestinal spore load was highest in bacteriocin/Au-NPs-inoculated mice (89.7%) followed by bacteriocin-inoculated group (73.5%). Spores encountered from stool of bacteriocin/Au-NPs group showed 92.4% viability, versus 93.7% in bacteriocin group. Spore extrusion and infectivity were most inhibited by exposure to bacteriocin/Au-NPs. Safety of bacteriocin/Au-NPs was also verified. Thus, considering the results of the present work, L. acidophilus CH1-derived bacteriocin can present a powerful safe therapy against intestinal microsporidiosis.

  15. Hydrogen production by Anabaena sp. CH1 with 2-stage process

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, C.L.; Lee, C.M. [National Chung Hsing Univ., Taiwan (China). Dept. of Environmental Engineering; Chen, P.C. [Hungkuang Univ., Taiwan (China). Dept. of Biomedical Nutrition

    2009-07-01

    While hydrogen can be produced by cyanobacteria under anoxic conditions, chlorophylls can break down and provide the nitrogen needed for cell material synthesis. The breakdown of chlorophylls is unfavorable for the long-term production of hydrogen. This study provided details of a 2-stage operation designed to prevent chlorophyll breakdown. Anabaena sp. CH1 was used in both the hydrogen production and recovery stages. Nitrogenase activity, chlorophyll concentrations, and hydrogen production rates decreased to 54 per cent after argon gases were used for a 3-day period. Growth conditions than shifted to normal conditions after 3 to 5 days. Cells recovered their nitrogenase activities, biomass, and chlorophyll concentrations within 4 days. The recovery stage then shifted to the hydrogen production stage, where hydrogen production rates were as high as previous observed rates. It was concluded that the effects of nitrogen deprivation on photosynthetic mechanisms are reversible.

  16. Research on the reduction of high concentrations of Cr(Ⅵ) with Leucobacter spp. Ch1%Leucobacter spp.菌株Ch1还原高浓度Cr(Ⅵ)的研究

    Institute of Scientific and Technical Information of China (English)

    马泽民; 朱文杰; 柴立元

    2008-01-01

    利用一株新分离Cr(Ⅵ)还原菌Leucobacter spp. Ch1进行高浓度Cr(Ⅵ)还原的研究.发现生长于Luria Broth培养基中的Leucobacter spp. Ch1最大能还原1800mg/LCr(Ⅵ),而休眠Leucobacter spp. Ch1细胞悬液可以完全还原2100mg/L Cr(Ⅵ).扫描电镜观察到还原cr(Ⅵ)后的细菌末端黏附大团反应产物,电子顺磁共振分析确定产物的成分为Cr(Ⅲ).在分批加Cr(Ⅵ)还原实验中,休眠Leucobacter spp. Ch1细胞悬液在1060min内还原了2368mg/L Cr(Ⅵ),重新加入的乳酸钠可以再次启动Cr(Ⅵ)的生物还原.结果表明,乳酸钠的存在是Leucobacter spp. Ch1还原Cr(Ⅵ)的必要条件,推测该物质在反应中起电子供体的作用.

  17. The emergence of alternative 3' and 5' splice site exons from constitutive exons.

    Directory of Open Access Journals (Sweden)

    Eli Koren

    2007-05-01

    Full Text Available Alternative 3' and 5' splice site (ss events constitute a significant part of all alternative splicing events. These events were also found to be related to several aberrant splicing diseases. However, only few of the characteristics that distinguish these events from alternative cassette exons are known currently. In this study, we compared the characteristics of constitutive exons, alternative cassette exons, and alternative 3'ss and 5'ss exons. The results revealed that alternative 3'ss and 5'ss exons are an intermediate state between constitutive and alternative cassette exons, where the constitutive side resembles constitutive exons, and the alternative side resembles alternative cassette exons. The results also show that alternative 3'ss and 5'ss exons exhibit low levels of symmetry (frame-preserving, similar to constitutive exons, whereas the sequence between the two alternative splice sites shows high symmetry levels, similar to alternative cassette exons. In addition, flanking intronic conservation analysis revealed that exons whose alternative splice sites are at least nine nucleotides apart show a high conservation level, indicating intronic participation in the regulation of their splicing, whereas exons whose alternative splice sites are fewer than nine nucleotides apart show a low conservation level. Further examination of these exons, spanning seven vertebrate species, suggests an evolutionary model in which the alternative state is a derivative of an ancestral constitutive exon, where a mutation inside the exon or along the flanking intron resulted in the creation of a new splice site that competes with the original one, leading to alternative splice site selection. This model was validated experimentally on four exons, showing that they indeed originated from constitutive exons that acquired a new competing splice site during evolution.

  18. Predicting mutually exclusive spliced exons based on exon length, splice site and reading frame conservation, and exon sequence homology

    Directory of Open Access Journals (Sweden)

    Hammesfahr Björn

    2011-06-01

    Full Text Available Abstract Background Alternative splicing of pre-mature RNA is an important process eukaryotes utilize to increase their repertoire of different protein products. Several types of different alternative splice forms exist including exon skipping, differential splicing of exons at their 3'- or 5'-end, intron retention, and mutually exclusive splicing. The latter term is used for clusters of internal exons that are spliced in a mutually exclusive manner. Results We have implemented an extension to the WebScipio software to search for mutually exclusive exons. Here, the search is based on the precondition that mutually exclusive exons encode regions of the same structural part of the protein product. This precondition provides restrictions to the search for candidate exons concerning their length, splice site conservation and reading frame preservation, and overall homology. Mutually exclusive exons that are not homologous and not of about the same length will not be found. Using the new algorithm, mutually exclusive exons in several example genes, a dynein heavy chain, a muscle myosin heavy chain, and Dscam were correctly identified. In addition, the algorithm was applied to the whole Drosophila melanogaster X chromosome and the results were compared to the Flybase annotation and an ab initio prediction. Clusters of mutually exclusive exons might be subsequent to each other and might encode dozens of exons. Conclusions This is the first implementation of an automatic search for mutually exclusive exons in eukaryotes. Exons are predicted and reconstructed in the same run providing the complete gene structure for the protein query of interest. WebScipio offers high quality gene structure figures with the clusters of mutually exclusive exons colour-coded, and several analysis tools for further manual inspection. The genome scale analysis of all genes of the Drosophila melanogaster X chromosome showed that WebScipio is able to find all but two of the 28

  19. Identification of protein features encoded by alternative exons using Exon Ontology.

    Science.gov (United States)

    Tranchevent, Léon-Charles; Aubé, Fabien; Dulaurier, Louis; Benoit-Pilven, Clara; Rey, Amandine; Poret, Arnaud; Chautard, Emilie; Mortada, Hussein; Desmet, François-Olivier; Chakrama, Fatima Zahra; Moreno-Garcia, Maira Alejandra; Goillot, Evelyne; Janczarski, Stéphane; Mortreux, Franck; Bourgeois, Cyril F; Auboeuf, Didier

    2017-06-01

    Transcriptomic genome-wide analyses demonstrate massive variation of alternative splicing in many physiological and pathological situations. One major challenge is now to establish the biological contribution of alternative splicing variation in physiological- or pathological-associated cellular phenotypes. Toward this end, we developed a computational approach, named "Exon Ontology," based on terms corresponding to well-characterized protein features organized in an ontology tree. Exon Ontology is conceptually similar to Gene Ontology-based approaches but focuses on exon-encoded protein features instead of gene level functional annotations. Exon Ontology describes the protein features encoded by a selected list of exons and looks for potential Exon Ontology term enrichment. By applying this strategy to exons that are differentially spliced between epithelial and mesenchymal cells and after extensive experimental validation, we demonstrate that Exon Ontology provides support to discover specific protein features regulated by alternative splicing. We also show that Exon Ontology helps to unravel biological processes that depend on suites of coregulated alternative exons, as we uncovered a role of epithelial cell-enriched splicing factors in the AKT signaling pathway and of mesenchymal cell-enriched splicing factors in driving splicing events impacting on autophagy. Freely available on the web, Exon Ontology is the first computational resource that allows getting a quick insight into the protein features encoded by alternative exons and investigating whether coregulated exons contain the same biological information. © 2017 Tranchevent et al.; Published by Cold Spring Harbor Laboratory Press.

  20. Mutation of the CH1 Domain in the Histone Acetyltransferase CREBBP Results in Autism-Relevant Behaviors in Mice.

    Science.gov (United States)

    Zheng, Fei; Kasper, Lawryn H; Bedford, David C; Lerach, Stephanie; Teubner, Brett J W; Brindle, Paul K

    2016-01-01

    Autism spectrum disorders (ASDs) are a group of neurodevelopmental afflictions characterized by repetitive behaviors, deficits in social interaction, and impaired communication skills. For most ASD patients, the underlying causes are unknown. Genetic mutations have been identified in about 25 percent of ASD cases, including mutations in epigenetic regulators, suggesting that dysregulated chromatin or DNA function is a critical component of ASD. Mutations in the histone acetyltransferase CREB binding protein (CBP, CREBBP) cause Rubinstein-Taybi Syndrome (RTS), a developmental disorder that includes ASD-like symptoms. Recently, genomic studies involving large numbers of ASD patient families have theoretically modeled CBP and its paralog p300 (EP300) as critical hubs in ASD-associated protein and gene interaction networks, and have identified de novo missense mutations in highly conserved residues of the CBP acetyltransferase and CH1 domains. Here we provide animal model evidence that supports this notion that CBP and its CH1 domain are relevant to autism. We show that mice with a deletion mutation in the CBP CH1 (TAZ1) domain (CBPΔCH1CH1) have an RTS-like phenotype that includes ASD-relevant repetitive behaviors, hyperactivity, social interaction deficits, motor dysfunction, impaired recognition memory, and abnormal synaptic plasticity. Our results therefore indicate that loss of CBP CH1 domain function contributes to RTS, and possibly ASD, and that this domain plays an essential role in normal motor function, cognition and social behavior. Although the key physiological functions affected by ASD-associated mutation of epigenetic regulators have been enigmatic, our findings are consistent with theoretical models involving CBP and p300 in ASD, and with a causative role for recently described ASD-associated CBP mutations.

  1. Chordoma-derived cell line U-CH1-N recapitulates the biological properties of notochordal nucleus pulposus cells.

    Science.gov (United States)

    Fujita, Nobuyuki; Suzuki, Satoshi; Watanabe, Kota; Ishii, Ken; Watanabe, Ryuichi; Shimoda, Masayuki; Takubo, Keiyo; Tsuji, Takashi; Toyama, Yoshiaki; Miyamoto, Takeshi; Horiuchi, Keisuke; Nakamura, Masaya; Matsumoto, Morio

    2016-08-01

    Intervertebral disc degeneration proceeds with age and is one of the major causes of lumbar pain and degenerative lumbar spine diseases. However, studies in the field of intervertebral disc biology have been hampered by the lack of reliable cell lines that can be used for in vitro assays. In this study, we show that a chordoma-derived cell line U-CH1-N cells highly express the nucleus pulposus (NP) marker genes, including T (encodes T brachyury transcription factor), KRT19, and CD24. These observations were further confirmed by immunocytochemistry and flow cytometry. Reporter analyses showed that transcriptional activity of T was enhanced in U-CH1-N cells. Chondrogenic capacity of U-CH1-N cells was verified by evaluating the expression of extracellular matrix (ECM) genes and Alcian blue staining. Of note, we found that proliferation and synthesis of chondrogenic ECM proteins were largely dependent on T in U-CH1-N cells. In accordance, knockdown of the T transcripts suppressed the expression of PCNA, a gene essential for DNA replication, and SOX5 and SOX6, the master regulators of chondrogenesis. On the other hand, the CD24-silenced cells showed no reduction in the mRNA expression level of the chondrogenic ECM genes. These results suggest that U-CH1-N shares important biological properties with notochordal NP cells and that T plays crucial roles in maintaining the notochordal NP cell-like phenotype in this cell line. Taken together, our data indicate that U-CH1-N may serve as a useful tool in studying the biology of intervertebral disc. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 34:1341-1350, 2016.

  2. Exon circularization in mammalian nuclear extracts.

    Science.gov (United States)

    Pasman, Z; Been, M D; Garcia-Blanco, M A

    1996-06-01

    Correct ligation of exons in pre-mRNA splicing requires splice site juxtaposition (splice site pairing), usually involving a 5' splice site and a downstream 3' splice site. Splicing of a 5' splice site to an upstream 3' splice site, however, is predicted to result in a circular RNA. This mode of splice site pairing across the axon has been hypothesized to account for rare RNAs containing scrambled exons (Nigro JM et al., 1991, Celt 64:607-613; Cocquerelle C et al., 1992, EMBO J 11:1 095-1098). Additionally, this mode of splice site pairing has been postulated to explain the formation of SRY circular transcripts in mouse testis (Capel B et al., 1993, Celt 73:1019- 1030). Here we show that splice site pairing across the exon can result in exon circularization in vitro. These results indicate that spliceosome-mediated axon circularization indeed can account for the formation of scrambled exons and circular RNAs. Exon circularization efficiency decreased dramatically as the length of the exon was increased from 95 nt to 274 nt. Circularization of this longer exon was restored, however, when intronic complementary sequences were included in the RNA substrate. These complementary sequences could form a stem that served to bring the splice sites into proximity and thereby promote splice site pairing. Therefore, the splicing of this structured RNA recapitulated SRY-like exon circularization in vitro.

  3. ExonMiner: Web service for analysis of GeneChip Exon array data

    Directory of Open Access Journals (Sweden)

    Imoto Seiya

    2008-11-01

    Full Text Available Abstract Background Some splicing isoform-specific transcriptional regulations are related to disease. Therefore, detection of disease specific splice variations is the first step for finding disease specific transcriptional regulations. Affymetrix Human Exon 1.0 ST Array can measure exon-level expression profiles that are suitable to find differentially expressed exons in genome-wide scale. However, exon array produces massive datasets that are more than we can handle and analyze on personal computer. Results We have developed ExonMiner that is the first all-in-one web service for analysis of exon array data to detect transcripts that have significantly different splicing patterns in two cells, e.g. normal and cancer cells. ExonMiner can perform the following analyses: (1 data normalization, (2 statistical analysis based on two-way ANOVA, (3 finding transcripts with significantly different splice patterns, (4 efficient visualization based on heatmaps and barplots, and (5 meta-analysis to detect exon level biomarkers. We implemented ExonMiner on a supercomputer system in order to perform genome-wide analysis for more than 300,000 transcripts in exon array data, which has the potential to reveal the aberrant splice variations in cancer cells as exon level biomarkers. Conclusion ExonMiner is well suited for analysis of exon array data and does not require any installation of software except for internet browsers. What all users need to do is to access the ExonMiner URL http://ae.hgc.jp/exonminer. Users can analyze full dataset of exon array data within hours by high-level statistical analysis with sound theoretical basis that finds aberrant splice variants as biomarkers.

  4. ExonMiner: Web service for analysis of GeneChip Exon array data

    Science.gov (United States)

    Numata, Kazuyuki; Yoshida, Ryo; Nagasaki, Masao; Saito, Ayumu; Imoto, Seiya; Miyano, Satoru

    2008-01-01

    Background Some splicing isoform-specific transcriptional regulations are related to disease. Therefore, detection of disease specific splice variations is the first step for finding disease specific transcriptional regulations. Affymetrix Human Exon 1.0 ST Array can measure exon-level expression profiles that are suitable to find differentially expressed exons in genome-wide scale. However, exon array produces massive datasets that are more than we can handle and analyze on personal computer. Results We have developed ExonMiner that is the first all-in-one web service for analysis of exon array data to detect transcripts that have significantly different splicing patterns in two cells, e.g. normal and cancer cells. ExonMiner can perform the following analyses: (1) data normalization, (2) statistical analysis based on two-way ANOVA, (3) finding transcripts with significantly different splice patterns, (4) efficient visualization based on heatmaps and barplots, and (5) meta-analysis to detect exon level biomarkers. We implemented ExonMiner on a supercomputer system in order to perform genome-wide analysis for more than 300,000 transcripts in exon array data, which has the potential to reveal the aberrant splice variations in cancer cells as exon level biomarkers. Conclusion ExonMiner is well suited for analysis of exon array data and does not require any installation of software except for internet browsers. What all users need to do is to access the ExonMiner URL . Users can analyze full dataset of exon array data within hours by high-level statistical analysis with sound theoretical basis that finds aberrant splice variants as biomarkers. PMID:19036125

  5. Identification of the ferric iron utilization gene B739_1208 and its role in the virulence of R. anatipestifer CH-1.

    Science.gov (United States)

    Wang, MengYi; Zhang, PengYun; Zhu, DeKang; Wang, MingShu; Jia, RenYong; Chen, Shun; Sun, KunFeng; Yang, Qiao; Wu, Ying; Chen, XiaoYue; Biville, Francis; Cheng, AnChun; Liu, MaFeng

    2017-03-01

    Riemerella anatipestifer is an important bacterial pathogen in ducks and causes heavy economic losses in the duck industry. However, the pathogensis of this bacterium is poorly understood. In this study, a putative outer membrane hemin receptor gene B739_1208 in R. anatipestifer CH-1 was deleted to determine the relationship between iron uptake and virulence. The R. anatipestifer CH-1ΔB739_1208 mutants grew significantly more slowly than the wild-type bacteria in TSB liquid medium. Further characterization revealed that the R. anatipestifer CH-1ΔB739_1208 mutants were deficient in iron uptake. Animal experiments indicated that the median lethal dose of the wild-type RA-CH-1 in ducklings was 3.89×10(8), whereas the median lethal dose of the R. anatipestifer CH-1ΔB739_1208 mutant in ducklings was 5.68×10(9). The median lethal dose of the complementation strain in ducklings was 9.84×10(8). Additional analysis indicated that bacterial loads in the blood, liver, and brain tissues in the R. anatipestifer CH-1ΔB739_1208-infected ducklings were significantly decreased compared to those in the wild-type R. anatipestifer CH-1 infected ducklings. In a duck co-infection model with R. anatipestifer CH-1 and R. anatipestifer CH-1ΔB739_1208, the R. anatipestifer CH-1B739_1208 mutant was outcompeted by the wild-type R. anatipestifer CH-1 in the blood (PR. anatipestifer CH-1. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Remarkable selective constraints on exonic dinucleotide repeats.

    Science.gov (United States)

    Haasl, Ryan J; Payseur, Bret A

    2014-09-01

    Long dinucleotide repeats found in exons present a substantial mutational hazard: mutations at these loci occur often and generate frameshifts. Here, we provide clear and compelling evidence that exonic dinucleotides experience strong selective constraint. In humans, only 18 exonic dinucleotides have repeat lengths greater than six, which contrasts sharply with the genome-wide distribution of dinucleotides. We genotyped each of these dinucleotides in 200 humans from eight 1000 Genomes Project populations and found a near-absence of polymorphism. More remarkably, divergence data demonstrate that repeat lengths have been conserved across the primate phylogeny in spite of what is likely considerable mutational pressure. Coalescent simulations show that even a very low mutation rate at these loci fails to explain the anomalous patterns of polymorphism and divergence. Our data support two related selective constraints on the evolution of exonic dinucleotides: a short-term intolerance for any change to repeat length and a long-term prevention of increases to repeat length. In general, our results implicate purifying selection as the force that eliminates new, deleterious mutants at exonic dinucleotides. We briefly discuss the evolution of the longest exonic dinucleotide in the human genome--a 10 x CA repeat in fibroblast growth factor receptor-like 1 (FGFRL1)--that should possess a considerably greater mutation rate than any other exonic dinucleotide and therefore generate a large number of deleterious variants. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  7. How are exons encoding transmembrane sequences distributed in the exon-intron structure of genes?

    Science.gov (United States)

    Sawada, Ryusuke; Mitaku, Shigeki

    2011-01-01

    The exon-intron structure of eukaryotic genes raises a question about the distribution of transmembrane regions in membrane proteins. Were exons that encode transmembrane regions formed simply by inserting introns into preexisting genes or by some kind of exon shuffling? To answer this question, the exon-per-gene distribution was analyzed for all genes in 40 eukaryotic genomes with a particular focus on exons encoding transmembrane segments. In 21 higher multicellular eukaryotes, the percentage of multi-exon genes (those containing at least one intron) within all genes in a genome was high (>70%) and with a mean of 87%. When genes were grouped by the number of exons per gene in higher eukaryotes, good exponential distributions were obtained not only for all genes but also for the exons encoding transmembrane segments, leading to a constant ratio of membrane proteins independent of the exon-per-gene number. The positional distribution of transmembrane regions in single-pass membrane proteins showed that they are generally located in the amino or carboxyl terminal regions. This nonrandom distribution of transmembrane regions explains the constant ratio of membrane proteins to the exon-per-gene numbers because there are always two terminal (i.e., the amino and carboxyl) regions - independent of the length of sequences.

  8. Exon-centric regulation of pyruvate kinase M alternative splicing via mutually exclusive exons

    Institute of Scientific and Technical Information of China (English)

    Zhenxun Wang; Deblina Chatterjee; Hyun Yong Jeon; Martin Akerman; Matthew G. Vander Heiden; Lewis C. Cantley; Adrian R. Krainer

    2012-01-01

    Alternative splicing of the pyruvate kinase M gene (PK-M) can generate the M2 isoform and promote aerobic glycolysis and tumor growth.However,the cancer-specific alternative splicing regulation of PK-M is not completely understood.Here,we demonstrate that PK-M is regulated by reciprocal affects on the mutually exclusive exons 9 and 10,such that exon 9 is repressed and exon 10 is activated in cancer cells.Strikingly,exonic,rather than intronic,cis-elements are key determinants ef PK-M splicing isoform ratios.Using a systematic sub-exonic duplication approach,we identify a potent exonlc splicing enhancer in exon 10,which differs from its homologous counterpart in exon 9 by only two nucleotides.We identify SRSF3 as one of the cognate factors,and show that this serine/arginine-rich protein activates exon 10 and mediates changes in glucose metabolism.These findings provide mechanistic insights into the complex regulation of alternative splicing of a key regulator of the Warburg effect,and also have implications for other genes with a similar pattern of alternative splicing.

  9. Faster exon assembly by sparse spliced alignment

    CERN Document Server

    Tiskin, Alexander

    2007-01-01

    Assembling a gene from candidate exons is an important problem in computational biology. Among the most successful approaches to this problem is \\emph{spliced alignment}, proposed by Gelfand et al., which scores different candidate exon chains within a DNA sequence of length $m$ by comparing them to a known related gene sequence of length n, $m = \\Theta(n)$. Gelfand et al.\\ gave an algorithm for spliced alignment running in time O(n^3). Kent et al.\\ considered sparse spliced alignment, where the number of candidate exons is O(n), and proposed an algorithm for this problem running in time O(n^{2.5}). We improve on this result, by proposing an algorithm for sparse spliced alignment running in time O(n^{2.25}). Our approach is based on a new framework of \\emph{quasi-local string comparison}.

  10. Identifying the Genes Responsible for Iron-Limited Condition in Riemerella anatipestifer CH-1 through RNA-Seq-Based Analysis

    Directory of Open Access Journals (Sweden)

    MaFeng Liu

    2017-01-01

    Full Text Available One of the important elements for most bacterial growth is iron, the bioavailability of which is limited in hosts. Riemerella anatipestifer (R. anatipestifer, RA, an important duck pathogen, requires iron to live. However, the genes involved in iron metabolism and the mechanisms of iron transport are largely unknown. Here, we investigated the transcriptomic effects of iron limitation condition on R. anatipestifer CH-1 using the RNA-Seq and RNA-Seq-based analysis. Data analysis revealed genes encoding functions related to iron homeostasis, including a number of putative TonB-dependent receptor systems, a HmuY-like protein-dependent hemin (an iron-containing porphyrin uptake system, a Feo system, a gene cluster related to starch utilization, and genes encoding hypothetical proteins that were significantly upregulated in response to iron limitation. Compared to the number of upregulated genes, more genes were significantly downregulated in response to iron limitation. The downregulated genes mainly encoded a number of outer membrane receptors, DNA-binding proteins, phage-related proteins, and many hypothetical proteins. This information suggested that RNA-Seq-based analysis in iron-limited medium is an effective and fast method for identifying genes involved in iron uptake in R. anatipestifer CH-1.

  11. Effect of exonic splicing regulation on synonymous codon usage in alternatively spliced exons of Dscam

    Directory of Open Access Journals (Sweden)

    Takahashi Aya

    2009-08-01

    Full Text Available Abstract Background Synonymous codon usage is typically biased towards translationally superior codons in many organisms. In Drosophila, genomic data indicates that translationally optimal codons and splice optimal codons are mostly mutually exclusive, and adaptation to translational efficiency is reduced in the intron-exon boundary regions where potential exonic splicing enhancers (ESEs reside. In contrast to genomic scale analyses on large datasets, a refined study on a well-controlled set of samples can be effective in demonstrating the effects of particular splice-related factors. Down syndrome cell adhesion molecule (Dscam has the largest number of alternatively spliced exons (ASEs known to date, and the splicing frequency of each ASE is accessible from the relative abundance of the transcript. Thus, these ASEs comprise a unique model system for studying the effect of splicing regulation on synonymous codon usage. Results Codon Bias Indices (CBI in the 3' boundary regions were reduced compared to the rest of the exonic regions among 48 and 33 ASEs of exon 6 and 9 clusters, respectively. These regional differences in CBI were affected by splicing frequency and distance from adjacent exons. Synonymous divergence levels between the 3' boundary region and the remaining exonic region of exon 6 ASEs were similar. Additionally, another sensitive comparison of paralogous exonic regions in recently retrotransposed processed genes and their parental genes revealed that, in the former, the differences in CBI between what were formerly the central regions and the boundary regions gradually became smaller over time. Conclusion Analyses of the multiple ASEs of Dscam allowed direct tests of the effect of splice-related factors on synonymous codon usage and provided clear evidence that synonymous codon usage bias is restricted by exonic splicing signals near the intron-exon boundary. A similar synonymous divergence level between the different exonic

  12. Targeted exon skipping to correct exon duplications in the dystrophin gene

    National Research Council Canada - National Science Library

    Greer, Kane L; Lochmüller, Hanns; Flanigan, Kevin; Fletcher, Susan; Wilton, Steve D

    2014-01-01

    .... Differences in exon-skipping efficiencies in vitro were observed between oligomer analogues of the same sequence, with the phosphorodiamidate morpholino oligomer coupled to a cell-penetrating peptide...

  13. Modulating Calcium Signals to Boost AON Exon Skipping for DMD

    Science.gov (United States)

    2016-10-01

    RyR antags for RNASeQ (18 months; 70% complete) We are in the process of prioritizing based on initial findings. As of now CDMD1003 exon 45...sequence analysis Subtask 1 - Optimize alternate splicing assay using exon capture and RNASeq (12 months, 80% complete). Additionally, we have...begun optimizing the exon capture and performed preliminary RNASeq experiments as described using exon capture. Subtask 2 - High depth RNASeQ on

  14. Exon - ASTRA | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data ...ontents Exons in variants Data file File name: astra_exon.zip File URL: ftp://ftp.biosciencedbc.jp/archive/a... About This Database Database Description Download License Update History of This Database Site Policy | Contact Us Exon - ASTRA | LSDB Archive ...

  15. PGC-1α regulates the cell cycle through ATP and ROS in CH1 cells%题目:PGC-1α在CH1细胞中通过ATP和ROS调控细胞周期

    Institute of Scientific and Technical Information of China (English)

    Xu-feng FU; Kun YAO; Xing DU; Yan LI; Xiu-yu YANG; Min YU; Mei-zhang LI; Qing-hua CUI

    2016-01-01

    Peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) is a transcriptional co-activator involved in mitochondrial biogenesis, respiratory capacity, and oxidative phosphorylation (OXPHOS). PGC-1α plays an important role in celular metabolism and is associated with tumorigenesis, suggesting an involvement in cel cycle progression. However, the underlying mechanisms mediating its involvement in these processes remain unclear. To elucidate the signaling pathways involved in PGC-1α function, we established a cel line, CH1 PGC-1α, which stably overexpresses PGC-1α. Using this cel line, we found that over-expression of PGC-1α stimulated extra adenosine triphosphate (ATP) and reduced reactive oxygen species (ROS) production. These effects were accompanied by up-regulation of the cel cycle checkpoint regulators CyclinD1 and CyclinB1. We hypothesized that ATP and ROS function as celular signals to regulate cyclins and control cel cycle progression. Indeed, we found that reduction of ATP levels down-regulated CyclinD1 but not CyclinB1, whereas elevation of ROS levels down-regulated CyclinB1 but not CyclinD1. Furthermore, both low ATP levels and elevated ROS levels inhibited cel growth, but PGC-1α was maintained at a constant level. Together, these results demonstrate that PGC-1α regulates cel cycle progression through modulation of CyclinD1 and CyclinB1 by ATP and ROS. These findings suggest that PGC-1α potentialy coordinates energy metabolism together with the cel cycle.%目的:探讨在 CH1细胞中过氧化物酶体增殖物受体γ共激活因子1α(PGC-1α)调控细胞周期时三磷酸腺苷(ATP)和活性氧(ROS)的作用机制。创新点:构建了稳定表达PGC-1α的CH1细胞株,并系统地研究了 PGC-1α调控细胞周期是通过 ATP 和ROS调节CyclinD1和CyclinB1的行使功能。方法:以慢病毒质粒 pBABE为载体构建了 PGC-1α稳定表达的CH1 PGC-1α细胞株(PGC-1α),同时转染空质粒pBABE

  16. The "alternative" choice of constitutive exons throughout evolution.

    Directory of Open Access Journals (Sweden)

    Galit Lev-Maor

    2007-11-01

    Full Text Available Alternative cassette exons are known to originate from two processes-exonization of intronic sequences and exon shuffling. Herein, we suggest an additional mechanism by which constitutively spliced exons become alternative cassette exons during evolution. We compiled a dataset of orthologous exons from human and mouse that are constitutively spliced in one species but alternatively spliced in the other. Examination of these exons suggests that the common ancestors were constitutively spliced. We show that relaxation of the 5' splice site during evolution is one of the molecular mechanisms by which exons shift from constitutive to alternative splicing. This shift is associated with the fixation of exonic splicing regulatory sequences (ESRs that are essential for exon definition and control the inclusion level only after the transition to alternative splicing. The effect of each ESR on splicing and the combinatorial effects between two ESRs are conserved from fish to human. Our results uncover an evolutionary pathway that increases transcriptome diversity by shifting exons from constitutive to alternative splicing.

  17. Transposable elements in disease-associated cryptic exons.

    Science.gov (United States)

    Vorechovsky, Igor

    2010-02-01

    Transposable elements (TEs) make up a half of the human genome, but the extent of their contribution to cryptic exon activation that results in genetic disease is unknown. Here, a comprehensive survey of 78 mutation-induced cryptic exons previously identified in 51 disease genes revealed the presence of TEs in 40 cases (51%). Most TE-containing exons were derived from short interspersed nuclear elements (SINEs), with Alus and mammalian interspersed repeats (MIRs) covering >18 and >16% of the exonized sequences, respectively. The majority of SINE-derived cryptic exons had splice sites at the same positions of the Alu/MIR consensus as existing SINE exons and their inclusion in the mRNA was facilitated by phylogenetically conserved changes that improved both traditional and auxiliary splicing signals, thus marking intronic TEs amenable for pathogenic exonization. The overrepresentation of MIRs among TE exons is likely to result from their high average exon inclusion levels, which reflect their strong splice sites, a lack of splicing silencers and a high density of enhancers, particularly (G)AA(G) motifs. These elements were markedly depleted in antisense Alu exons, had the most prominent position on the exon-intron gradient scale and are proposed to promote exon definition through enhanced tertiary RNA interactions involving unpaired (di)adenosines. The identification of common mechanisms by which the most dynamic parts of the genome contribute both to new exon creation and genetic disease will facilitate detection of intronic mutations and the development of computational tools that predict TE hot-spots of cryptic exon activation.

  18. In vitro characterization of cells derived from chordoma cell line U-CH1 following treatment with X-rays, heavy ions and chemotherapeutic drugs

    Directory of Open Access Journals (Sweden)

    Uesaka Mitsuru

    2011-09-01

    Full Text Available Abstract Background Chordoma, a rare cancer, is usually treated with surgery and/or radiation. However, very limited characterizations of chordoma cells are available due to a minimal availability (only two lines validated by now and the extremely long doubling time. In order to overcome this situation, we successfully derived a cell line with a shorter doubling time from the first validated chordoma line U-CH1 and obtained invaluable cell biological data. Method After isolating a subpopulation of U-CH1 cells with a short doubling time (U-CH1-N, cell growth, cell cycle distribution, DNA content, chromosome number, p53 status, and cell survival were examined after exposure to X-rays, heavy ions, camptothecin, mitomycin C, cisplatin and bleocin. These data were compared with those of HeLa (cervical cancer and U87-MG (glioblastoma cells. Results The cell doubling times for HeLa, U87-MG and U-CH1-N were approximately 18 h, 24 h and 3 days respectively. Heavy ion irradiation resulted in more efficient cell killing than x-rays in all three cell lines. Relative biological effectiveness (RBE at 10% survival for U-CH1-N was about 2.45 for 70 keV/μm carbon and 3.86 for 200 keV/μm iron ions. Of the four chemicals, bleocin showed the most marked cytotoxic effect on U-CH1-N. Conclusion Our data provide the first comprehensive cellular characterization using cells of chordoma origin and furnish the biological basis for successful clinical results of chordoma treatment by heavy ions.

  19. Exonic splicing regulatory elements skew synonymous codon usage near intron-exon boundaries in mammals.

    NARCIS (Netherlands)

    Parmley, J.L.; Hurst, L.D.

    2007-01-01

    In mammals there is a bias in amino acid usage near splice sites that is explained, in large part, by the high density of exonic splicing enhancers (ESEs) in these regions. Is there a similar bias for the relative use of synonymous codons, and can any such bias be predicted by their abundance in ESE

  20. Species-Specific Exon Loss in Human Transcriptomes

    OpenAIRE

    Wang, Jinkai; Lu, Zhi-xiang; Tokheim, Collin J.; Miller, Sara E.; Xing, Yi

    2014-01-01

    Changes in exon–intron structures and splicing patterns represent an important mechanism for the evolution of gene functions and species-specific regulatory networks. Although exon creation is widespread during primate and human evolution and has been studied extensively, much less is known about the scope and potential impact of human-specific exon loss events. Historically, transcriptome data and exon annotations are significantly biased toward humans over nonhuman primates. This ascertainm...

  1. Exon Deletions of Parkin Gene in Patients with Parkinson Disease

    Institute of Scientific and Technical Information of China (English)

    王涛; 梁直厚; 孙圣刚; 曹学兵; 彭海; 刘红进; 童萼塘

    2004-01-01

    Summary: Mutations in the parkin gene have recently been identified in familial and isolated patients with early-onset Parkinson disease (PD) and that subregions between exon 2 and 4 of the parkin gene are hot spots of deletive mutations. To study the distribution of deletions in the parkin gene among variant subset patients with PD in China, and to explore the role of parkin gene in the pathogenesis of PD, 63 patients were divided into early onset and later onset groups. Exons 1-12 were amplified by PCR, templated by the genomic DNA of patients, and then the deletion distribution detected by agarose electrophoresis. Four patients were found to be carrier of exon deletions in 63 patients with PD. The location of the deletion was on exon 2 (1 case), exon 3 (2 cases) and exon 4 (1 case). All patients were belong to the group of early onset PD. The results showed that parkin gene deletion on exon 2, exon 3 and exon 4 found in Chinese population contributes partly to early onset PD.

  2. Characteristics of transposable element exonization within human and mouse.

    Directory of Open Access Journals (Sweden)

    Noa Sela

    Full Text Available Insertion of transposed elements within mammalian genes is thought to be an important contributor to mammalian evolution and speciation. Insertion of transposed elements into introns can lead to their activation as alternatively spliced cassette exons, an event called exonization. Elucidation of the evolutionary constraints that have shaped fixation of transposed elements within human and mouse protein coding genes and subsequent exonization is important for understanding of how the exonization process has affected transcriptome and proteome complexities. Here we show that exonization of transposed elements is biased towards the beginning of the coding sequence in both human and mouse genes. Analysis of single nucleotide polymorphisms (SNPs revealed that exonization of transposed elements can be population-specific, implying that exonizations may enhance divergence and lead to speciation. SNP density analysis revealed differences between Alu and other transposed elements. Finally, we identified cases of primate-specific Alu elements that depend on RNA editing for their exonization. These results shed light on TE fixation and the exonization process within human and mouse genes.

  3. Scanning for genes in large genomic regions: cosmid-based exon trapping of multiple exons in a single product.

    Science.gov (United States)

    Datson, N A; van de Vosse, E; Dauwerse, H G; Bout, M; van Ommen, G J; den Dunnen, J T

    1996-03-15

    To facilitate the scanning of large genomic regions for the presence of exonic gene segments we have constructed a cosmid-based exon trap vector. The vector serves a dual purpose since it is also suitable for contig construction and physical mapping. The exon trap cassette of vector sCOGH1 consists of the human growth hormone gene driven by the mouse mettallothionein-1 promoter. Inserts are cloned in the multicloning site located in intron 2 of the hGH gene. The efficiency of the system is demonstrated with cosmids containing multiple exons of the Duchenne Muscular Dystrophy gene. All exons present in the inserts were successfully retrieved and no cryptic products were detected. Up to seven exons were isolated simultaneously in a single spliced product. The system has been extended by a transcription-translation-test protocol to determine the presence of large open reading frames in the trapped products, using a combination of tailed PCR primers directing protein synthesis in three different reading frames, followed by in vitro transcription-translation. Having larger stretches of coding sequence in a single exon trap product rather than small single exons greatly facilitates further analysis of potential genes and offers new possibilities for direct mutation analysis of exon trap material.

  4. Exon exchange approach to repair Duchenne dystrophin transcripts.

    Directory of Open Access Journals (Sweden)

    Stéphanie Lorain

    Full Text Available BACKGROUND: Trans-splicing strategies for mRNA repair involve engineered transcripts designed to anneal target mRNAs in order to interfere with their natural splicing, giving rise to mRNA chimeras where endogenous mutated exons have been replaced by exogenous replacement sequences. A number of trans-splicing molecules have already been proposed for replacing either the 5' or the 3' part of transcripts to be repaired. Here, we show the feasibility of RNA surgery by using a double trans-splicing approach allowing the specific substitution of a given mutated exon. METHODOLOGY/PRINCIPAL FINDINGS: As a target we used a minigene encoding a fragment of the mdx dystrophin gene enclosing the mutated exon (exon 23. This minigene was cotransfected with a variety of exon exchange constructions, differing in their annealing domains. We obtained accurate and efficient replacement of exon 23 in the mRNA target. Adding up a downstream intronic splice enhancer DISE in the exon exchange molecule enhanced drastically its efficiency up to 25-45% of repair depending on the construction in use. CONCLUSIONS/SIGNIFICANCE: These results demonstrate the possibility to fix up mutated exons, refurbish deleted exons and introduce protein motifs, while keeping natural untranslated sequences, which are essential for mRNA stability and translation regulation. Conversely to the well-known exon skipping, exon exchange has the advantage to be compatible with almost any type of mutations and more generally to a wide range of genetic conditions. In particular, it allows addressing disorders caused by dominant mutations.

  5. Deletion of the Chd6 exon 12 affects motor coordination.

    Science.gov (United States)

    Lathrop, Melissa J; Chakrabarti, Lisa; Eng, Jeremiah; Rhodes, C Harker; Lutz, Thomas; Nieto, Amelia; Liggitt, H Denny; Warner, Sandra; Fields, Jennifer; Stöger, Reinhard; Fiering, Steven

    2010-04-01

    Members of the CHD protein family play key roles in gene regulation through ATP-dependent chromatin remodeling. This is facilitated by chromodomains that bind histone tails, and by the SWI2/SNF2-like ATPase/helicase domain that remodels chromatin by moving histones. Chd6 is ubiquitously expressed in both mouse and human, with the highest levels of expression in the brain. The Chd6 gene contains 37 exons, of which exons 12-19 encode the highly conserved ATPase domain. To determine the biological role of Chd6, we generated mouse lines with a deletion of exon 12. Chd6 without exon 12 is expressed at normal levels in mice, and Chd6 Exon 12 -/- mice are viable, fertile, and exhibit no obvious morphological or pathological phenotype. Chd6 Exon 12 -/- mice lack coordination as revealed by sensorimotor analysis. Further behavioral testing revealed that the coordination impairment was not due to muscle weakness or bradykinesia. Histological analysis of brain morphology revealed no differences between Chd6 Exon 12 -/- mice and wild-type (WT) controls. The location of CHD6 on human chromosome 20q12 is overlapped by the linkage map regions of several human ataxias, including autosomal recessive infantile cerebellar ataxia (SCAR6), a nonprogressive cerebrospinal ataxia. The genomic location, expression pattern, and ataxic phenotype of Chd6 Exon 12 -/- mice indicate that mutations within CHD6 may be responsible for one of these ataxias.

  6. Sequence Analysis of Hoxc8 Exon-1 and Exon-2 of Multi-Vertebrae Mongolia Sheep%多脊椎蒙古羊Hoxc8 exon-1和exon-2的序列分析

    Institute of Scientific and Technical Information of China (English)

    陈琦; 赵静; 张立岭; 马月辉

    2011-01-01

    参考牛的Hoxc8基因序列设计引物,扩增正常蒙古羊(胸椎数13)和多脊椎蒙古羊(胸椎数14)Hoxc8的exon-1和exon-2基因,对得到的序列进行生物信息学分析。结果表明,经序列比对二者的DNA序列,除两侧个别碱基有差异外,中间序列完全一致。蒙古羊Hoxc8的exon-1和exon-2序列分别与其他物种进行同源性比对,蒙古羊Hoxc8 exon-1与人、小鼠、大鼠、犬的同源性达到96%以上,与斑马鱼的同源性为75.8%;exon-2与大猩猩、犬、人、小鼠、大鼠的同源性达到91%以上,与斑马鱼的同源性%In our study,according to the Hoxc8 sequence of cow,the specific primers were designed,and the sequences of Hoxc8 exon-1(432 bp)and exon-2(273 bp)of normal and multi-thoracic vertebrae mongolia sheep were obtained(Genebank accession number: EU817489 and FJ905472).Alignment results of them indicated that the sequences were conformity except a little difference in two sides of sequences.Hoxc8 exon-1 and exon-2 were aligned with other species and the results showed that compared with other mammals(human,dog,mouse,rat and chimpanzee),the homology were above 96%(exon-1) and 91%(exon-2);compared with zebra fish,the homology were 75.8% and 74%.

  7. Deletion of Dystrophin In-Frame Exon 5 Leads to a Severe Phenotype: Guidance for Exon Skipping Strategies.

    Directory of Open Access Journals (Sweden)

    Zhi Yon Charles Toh

    Full Text Available Duchenne and Becker muscular dystrophy severity depends upon the nature and location of the DMD gene lesion and generally correlates with the dystrophin open reading frame. However, there are striking exceptions where an in-frame genomic deletion leads to severe pathology or protein-truncating mutations (nonsense or frame-shifting indels manifest as mild disease. Exceptions to the dystrophin reading frame rule are usually resolved after molecular diagnosis on muscle RNA. We report a moderate/severe Becker muscular dystrophy patient with an in-frame genomic deletion of DMD exon 5. This mutation has been reported by others as resulting in Duchenne or Intermediate muscular dystrophy, and the loss of this in-frame exon in one patient led to multiple splicing events, including omission of exon 6, that disrupts the open reading frame and is consistent with a severe phenotype. The patient described has a deletion of dystrophin exon 5 that does not compromise recognition of exon 6, and although the deletion does not disrupt the reading frame, his clinical presentation is more severe than would be expected for classical Becker muscular dystrophy. We suggest that the dystrophin isoform lacking the actin-binding sequence encoded by exon 5 is compromised, reflected by the phenotype resulting from induction of this dystrophin isoform in mouse muscle in vivo. Hence, exon skipping to address DMD-causing mutations within DMD exon 5 may not yield an isoform that confers marked clinical benefit. Additional studies will be required to determine whether multi-exon skipping strategies could yield more functional dystrophin isoforms, since some BMD patients with larger in-frame deletions in this region have been reported with mild phenotypes.

  8. Scanning for genes in large genomic regions: cosmid-based exon trapping of multiple exons in a single product.

    OpenAIRE

    Datson, N.A.; Vosse, E van de; Dauwerse, H.G.; Bout, M; van Ommen, G J; J T den Dunnen

    1996-01-01

    To facilitate the scanning of large genomic regions for the presence of exonic gene segments we have constructed a cosmid-based exon trap vector. The vector serves a dual purpose since it is also suitable for contig construction and physical mapping. The exon trap cassette of vector sCOGH1 consists of the human growth hormone gene driven by the mouse mettallothionein-1 promoter. Inserts are cloned in the multicloning site located in intron 2 of the hGH gene. The efficiency of the system is de...

  9. Differentiated evolutionary rates in alternative exons and the implications for splicing regulation

    Directory of Open Access Journals (Sweden)

    Eyras Eduardo

    2006-06-01

    Full Text Available Abstract Background Alternatively spliced exons play an important role in the diversification of gene function in most metazoans and are highly regulated by conserved motifs in exons and introns. Two contradicting properties have been associated to evolutionary conserved alternative exons: higher sequence conservation and higher rate of non-synonymous substitutions, relative to constitutive exons. In order to clarify this issue, we have performed an analysis of the evolution of alternative and constitutive exons, using a large set of protein coding exons conserved between human and mouse and taking into account the conservation of the transcript exonic structure. Further, we have also defined a measure of the variation of the arrangement of exonic splicing enhancers (ESE-conservation score to study the evolution of splicing regulatory sequences. We have used this measure to correlate the changes in the arrangement of ESEs with the divergence of exon and intron sequences. Results We find evidence for a relation between the lack of conservation of the exonic structure and the weakening of the sequence evolutionary constraints in alternative and constitutive exons. Exons in transcripts with non-conserved exonic structures have higher synonymous (dS and non-synonymous (dN substitution rates than exons in conserved structures. Moreover, alternative exons in transcripts with non-conserved exonic structure are the least constrained in sequence evolution, and at high EST-inclusion levels they are found to be very similar to constitutive exons, whereas alternative exons in transcripts with conserved exonic structure have a dS significantly lower than average at all EST-inclusion levels. We also find higher conservation in the arrangement of ESEs in constitutive exons compared to alternative ones. Additionally, the sequence conservation at flanking introns remains constant for constitutive exons at all ESE-conservation values, but increases for

  10. Origin of introns by 'intronization' of exonic sequences

    DEFF Research Database (Denmark)

    Irimia, Manuel; Rukov, Jakob Lewin; Penny, David;

    2008-01-01

    The mechanisms of spliceosomal intron creation have proved elusive. Here we describe a new mechanism: the recruitment of internal exonic sequences ('intronization') in Caenorhabditis species. The numbers of intronization events and introns gained by other mechanisms are similar, suggesting...

  11. Widespread evolutionary conservation of alternatively spliced exons in caenorhabditis

    DEFF Research Database (Denmark)

    Irimia, Manuel; Rukov, Jakob L; Penny, David

    2007-01-01

    Alternative splicing (AS) contributes to increased transcriptome and proteome diversity in various eukaryotic lineages. Previous studies showed low levels of conservation of alternatively spliced (cassette) exons within mammals and within dipterans. We report a strikingly different pattern...

  12. Exon silencing by UAGG motifs in response to neuronal excitation.

    Directory of Open Access Journals (Sweden)

    Ping An

    2007-02-01

    Full Text Available Alternative pre-mRNA splicing plays fundamental roles in neurons by generating functional diversity in proteins associated with the communication and connectivity of the synapse. The CI cassette of the NMDA R1 receptor is one of a variety of exons that show an increase in exon skipping in response to cell excitation, but the molecular nature of this splicing responsiveness is not yet understood. Here we investigate the molecular basis for the induced changes in splicing of the CI cassette exon in primary rat cortical cultures in response to KCl-induced depolarization using an expression assay with a tight neuron-specific readout. In this system, exon silencing in response to neuronal excitation was mediated by multiple UAGG-type silencing motifs, and transfer of the motifs to a constitutive exon conferred a similar responsiveness by gain of function. Biochemical analysis of protein binding to UAGG motifs in extracts prepared from treated and mock-treated cortical cultures showed an increase in nuclear hnRNP A1-RNA binding activity in parallel with excitation. Evidence for the role of the NMDA receptor and calcium signaling in the induced splicing response was shown by the use of specific antagonists, as well as cell-permeable inhibitors of signaling pathways. Finally, a wider role for exon-skipping responsiveness is shown to involve additional exons with UAGG-related silencing motifs, and transcripts involved in synaptic functions. These results suggest that, at the post-transcriptional level, excitable exons such as the CI cassette may be involved in strategies by which neurons mount adaptive responses to hyperstimulation.

  13. Tdp-43 cryptic exons are highly variable between cell types.

    Science.gov (United States)

    Jeong, Yun Ha; Ling, Jonathan P; Lin, Sophie Z; Donde, Aneesh N; Braunstein, Kerstin E; Majounie, Elisa; Traynor, Bryan J; LaClair, Katherine D; Lloyd, Thomas E; Wong, Philip C

    2017-02-02

    TDP-43 proteinopathy is a prominent pathological feature that occurs in a number of human diseases including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and inclusion body myositis (IBM). Our recent finding that TDP-43 represses nonconserved cryptic exons led us to ask whether cell type-specific cryptic exons could exist to impact unique molecular pathways in brain or muscle. In the present work, we investigated TDP-43's function in various mouse tissues to model disease pathogenesis. We generated mice to conditionally delete TDP-43 in excitatory neurons or skeletal myocytes and identified the cell type-specific cryptic exons associated with TDP-43 loss of function. Comparative analysis of nonconserved cryptic exons in various mouse cell types revealed that only some cryptic exons were common amongst stem cells, neurons, and myocytes; the majority of these nonconserved cryptic exons were cell type-specific. Our results suggest that in human disease, TDP-43 loss of function may impair cell type-specific pathways.

  14. The silent mutation nucleotide 744 G --> A, Lys172Lys, in exon 6 of BRCA2 results in exon skipping

    DEFF Research Database (Denmark)

    Hansen, Thomas V O; Steffensen, Ane Y; Jønson, Lars

    2009-01-01

    Germ-line mutations in BRCA2 predispose to breast and ovarian cancer. Mutations are widespread throughout the gene and include disease-causing mutations as frameshift, nonsense, splicing mutations and large genomic rearrangements. However a large number of mutations, including missense, silent...... and intron variants are of unknown significance. Here, we describe the functional characterization of a silent mutation (nucleotide 744 G --> A/c.516 G --> A, Lys172Lys) in exon 6 of BRCA2 in a Danish family with breast and ovarian cancer. Exon trapping analysis showed that the mutation results in skipping...... of exon 6 and/or both exon 5 and 6, which was verified by RT-PCR analysis on RNA isolated from whole blood of the affected patient. We therefore conclude that the BRCA2 silent mutation Lys172Lys is a disease-causing mutation....

  15. An RRM-ZnF RNA recognition module targets RBM10 to exonic sequences to promote exon exclusion.

    Science.gov (United States)

    Collins, Katherine M; Kainov, Yaroslav A; Christodolou, Evangelos; Ray, Debashish; Morris, Quaid; Hughes, Timothy; Taylor, Ian A; Makeyev, Eugene V; Ramos, Andres

    2017-04-04

    RBM10 is an RNA-binding protein that plays an essential role in development and is frequently mutated in the context of human disease. RBM10 recognizes a diverse set of RNA motifs in introns and exons and regulates alternative splicing. However, the molecular mechanisms underlying this seemingly relaxed sequence specificity are not understood and functional studies have focused on 3΄ intronic sites only. Here, we dissect the RNA code recognized by RBM10 and relate it to the splicing regulatory function of this protein. We show that a two-domain RRM1-ZnF unit recognizes a GGA-centered motif enriched in RBM10 exonic sites with high affinity and specificity and test that the interaction with these exonic sequences promotes exon skipping. Importantly, a second RRM domain (RRM2) of RBM10 recognizes a C-rich sequence, which explains its known interaction with the intronic 3΄ site of NUMB exon 9 contributing to regulation of the Notch pathway in cancer. Together, these findings explain RBM10's broad RNA specificity and suggest that RBM10 functions as a splicing regulator using two RNA-binding units with different specificities to promote exon skipping.

  16. Intron phase correlations and the evolution of the intron/exon structure of genes.

    Science.gov (United States)

    Long, M; Rosenberg, C; Gilbert, W

    1995-01-01

    Two issues in the evolution of the intron/exon structure of genes are the role of exon shuffling and the origin of introns. Using a large data base of eukaryotic intron-containing genes, we have found that there are correlations between intron phases leading to an excess of symmetric exons and symmetric exon sets. We interpret these excesses as manifestations of exon shuffling and make a conservative estimate that at least 19% of the exons in the data base were involved in exon shuffling, suggesting an important role for exon shuffling in evolution. Furthermore, these excesses of symmetric exons appear also in those regions of eukaryotic genes that are homologous to prokaryotic genes: the ancient conserved regions. This last fact cannot be explained in terms of the insertional theory of introns but rather supports the concept that some of the introns were ancient, the exon theory of genes. PMID:8618928

  17. First Exon Length Controls Active Chromatin Signatures and Transcription

    Directory of Open Access Journals (Sweden)

    Nicole I. Bieberstein

    2012-07-01

    Full Text Available Here, we explore the role of splicing in transcription, employing both genome-wide analysis of human ChIP-seq data and experimental manipulation of exon-intron organization in transgenic cell lines. We show that the activating histone modifications H3K4me3 and H3K9ac map specifically to first exon-intron boundaries. This is surprising, because these marks help recruit general transcription factors (GTFs to promoters. In genes with long first exons, promoter-proximal levels of H3K4me3 and H3K9ac are greatly reduced; consequently, GTFs and RNA polymerase II are low at transcription start sites (TSSs and exhibit a second, promoter-distal peak from which transcription also initiates. In contrast, short first exons lead to increased H3K4me3 and H3K9ac at promoters, higher expression levels, accuracy in TSS usage, and a lower frequency of antisense transcription. Therefore, first exon length is predictive for gene activity. Finally, splicing inhibition and intron deletion reduce H3K4me3 levels and transcriptional output. Thus, gene architecture and splicing determines transcription quantity and quality as well as chromatin signatures.

  18. Antisense-mediated exon skipping to reframe transcripts.

    Science.gov (United States)

    Turczynski, Sandrina; Titeux, Matthias; Pironon, Nathalie; Hovnanian, Alain

    2012-01-01

    Numerous genetic disorders are caused by loss-of-function mutations that disrupt the open reading frame of the gene either by nonsense or by frameshift (insertion, deletion, indel, or splicing) mutations. Most of the time, the result is the absence of functional protein synthesis due to mRNA degradation by nonsense-mediated mRNA decay, or rapid degradation of a truncated protein. Antisense-based splicing modulation is a powerful tool that has the potential to treat genetic disorders by restoring the open reading frame through selective removal of the mutated exon, or by restoring correct splicing.We have developed this approach for a severe genetic skin disorder, recessive dystrophic epidermolysis bullosa, caused by mutations in the COL7A1 gene encoding type VII collagen. This gene is particularly suited for exon-skipping approaches due to its unique genomic structure. It is composed of 118 exons, 83 of which are in frame. Moreover, these exons encode a single repetitive collagenous domain.Using this gene as an example, we describe general methods that demonstrate the feasibility and efficacy of the antisense-mediated exon-skipping strategy to reframe transcripts.

  19. Intron Retention and TE Exonization Events in ZRANB2

    Directory of Open Access Journals (Sweden)

    Sang-Je Park

    2012-01-01

    Full Text Available The Zinc finger, RAN-binding domain-containing protein 2 (ZRANB2, contains arginine/serine-rich (RS domains that mediate its function in the regulation of alternative splicing. The ZRANB2 gene contains 2 LINE elements (L3b, Plat_L3 between the 9th and 10th exons. We identified the exonization event of a LINE element (Plat_L3. Using genomic PCR, RT-PCR amplification, and sequencing of primate DNA and RNA samples, we analyzed the evolutionary features of ZRANB2 transcripts. The results indicated that 2 of the LINE elements were integrated in human and all of the tested primate samples (hominoids: 3 species; Old World monkey: 8 species; New World monkey: 6 species; prosimian: 1 species. Human, rhesus monkey, crab-eating monkey, African-green monkey, and marmoset harbor the exon derived from LINE element (Plat_L3. RT-PCR amplification revealed the long transcripts and their differential expression patterns. Intriguingly, these long transcripts were abundantly expressed in Old World monkey lineages (rhesus, crab-eating, and African-green monkeys and were expressed via intron retention (IR. Thus, the ZRANB2 gene produces 3 transcript variants in which the Cterminus varies by transposable elements (TEs exonization and IR mechanisms. Therefore, ZRANB2 is valuable for investigating the evolutionary mechanisms of TE exonization and IR during primate evolution.

  20. Recombinant Exon-Encoded Resilins for Elastomeric Biomaterials

    Science.gov (United States)

    Qin, Guokui; Rivkin, Amit; Lapidot, Shaul; Hu, Xiao; Arinus, Shira B.; Dgany, Or; Shoseyov, Oded; Kaplan, David L.

    2011-01-01

    Resilin is an elastomeric protein found in specialized regions of the cuticle of most insects, providing outstanding material properties including high resilience and fatigue lifetime for insect flight and jumping needs. Two exons (1 and 3) from the resilin gene in Drosophila melanogaster were cloned and the encoded proteins expressed as soluble products in Escherichia coli. A heat and salt precipitation method was used for efficient purification of the recombinant proteins. The proteins were solution cast from water and formed into rubber-like biomaterials via horseradish peroxidase-mediated cross-linking. Comparative studies of the two proteins expressed from the two different exons were investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Circular Dichrosim (CD) for structural features. Little structural organization was found, suggesting structural order was not induced by the enzyme-mediateed dityrosine cross-links. Atomic Force Microscopy (AFM) was used to study the elastomeric properties of the uncross-linked and cross-linked proteins. The protein from exon 1 exhibited 90% resilience in comparison to 63% for the protein from exon 3, and therefore may be the more critical domain for functional materials to mimic native resilin. Further, the cross-linking of the recombinant exon 1 via the citrate-modified photo-Fenton reaction was explored as an alternative dityrosine mediated polymerization method and resulted in both highly elastic and adhesive materials. The citrate-modified photo-Fenton system may be suitable for in-vivo applications of resilin biomaterials. PMID:21963157

  1. Large-scale remodeling of a repressed exon ribonucleoprotein to an exon definition complex active for splicing.

    Science.gov (United States)

    Wongpalee, Somsakul Pop; Vashisht, Ajay; Sharma, Shalini; Chui, Darryl; Wohlschlegel, James A; Black, Douglas L

    2016-11-24

    Polypyrimidine-tract binding protein PTBP1 can repress splicing during the exon definition phase of spliceosome assembly, but the assembly steps leading to an exon definition complex (EDC) and how PTBP1 might modulate them are not clear. We found that PTBP1 binding in the flanking introns allowed normal U2AF and U1 snRNP binding to the target exon splice sites but blocked U2 snRNP assembly in HeLa nuclear extract. Characterizing a purified PTBP1-repressed complex, as well as an active early complex and the final EDC by SILAC-MS, we identified extensive PTBP1-modulated changes in exon RNP composition. The active early complex formed in the absence of PTBP1 proceeded to assemble an EDC with the eviction of hnRNP proteins, the late recruitment of SR proteins, and binding of the U2 snRNP. These results demonstrate that during early stages of splicing, exon RNP complexes are highly dynamic with many proteins failing to bind during PTBP1 arrest.

  2. Automatic detection of exonic splicing enhancers (ESEs using SVMs

    Directory of Open Access Journals (Sweden)

    Suhai Sándor

    2008-09-01

    Full Text Available Abstract Background Exonic splicing enhancers (ESEs activate nearby splice sites and promote the inclusion (vs. exclusion of exons in which they reside, while being a binding site for SR proteins. To study the impact of ESEs on alternative splicing it would be useful to have a possibility to detect them in exons. Identifying SR protein-binding sites in human DNA sequences by machine learning techniques is a formidable task, since the exon sequences are also constrained by their functional role in coding for proteins. Results The choice of training examples needed for machine learning approaches is difficult since there are only few exact locations of human ESEs described in the literature which could be considered as positive examples. Additionally, it is unclear which sequences are suitable as negative examples. Therefore, we developed a motif-oriented data-extraction method that extracts exon sequences around experimentally or theoretically determined ESE patterns. Positive examples are restricted by heuristics based on known properties of ESEs, e.g. location in the vicinity of a splice site, whereas negative examples are taken in the same way from the middle of long exons. We show that a suitably chosen SVM using optimized sequence kernels (e.g., combined oligo kernel can extract meaningful properties from these training examples. Once the classifier is trained, every potential ESE sequence can be passed to the SVM for verification. Using SVMs with the combined oligo kernel yields a high accuracy of about 90 percent and well interpretable parameters. Conclusion The motif-oriented data-extraction method seems to produce consistent training and test data leading to good classification rates and thus allows verification of potential ESE motifs. The best results were obtained using an SVM with the combined oligo kernel, while oligo kernels with oligomers of a certain length could be used to extract relevant features.

  3. Antisense-induced exon skipping for duplications in Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    van Ommen Gert-Jan B

    2007-07-01

    Full Text Available Abstract Background Antisense-mediated exon skipping is currently one of the most promising therapeutic approaches for Duchenne muscular dystrophy (DMD. Using antisense oligonucleotides (AONs targeting specific exons the DMD reading frame is restored and partially functional dystrophins are produced. Following proof of concept in cultured muscle cells from patients with various deletions and point mutations, we now focus on single and multiple exon duplications. These mutations are in principle ideal targets for this approach since the specific skipping of duplicated exons would generate original, full-length transcripts. Methods Cultured muscle cells from DMD patients carrying duplications were transfected with AONs targeting the duplicated exons, and the dystrophin RNA and protein were analyzed. Results For two brothers with an exon 44 duplication, skipping was, even at suboptimal transfection conditions, so efficient that both exons 44 were skipped, thus generating, once more, an out-of-frame transcript. In such cases, one may resort to multi-exon skipping to restore the reading frame, as is shown here by inducing skipping of exon 43 and both exons 44. By contrast, in cells from a patient with an exon 45 duplication we were able to induce single exon 45 skipping, which allowed restoration of wild type dystrophin. The correction of a larger duplication (involving exons 52 to 62, by combinations of AONs targeting the outer exons, appeared problematic due to inefficient skipping and mistargeting of original instead of duplicated exons. Conclusion The correction of DMD duplications by exon skipping depends on the specific exons targeted. Its options vary from the ideal one, restoring for the first time the true, wild type dystrophin, to requiring more 'classical' skipping strategies, while the correction of multi-exon deletions may need the design of tailored approaches.

  4. Splicing of phenylalanine hydroxylase (PAH) exon 11 is vulnerable - Molecular pathology of mutations in PAH exon 11

    DEFF Research Database (Denmark)

    Heintz, Caroline; Dobrowolski, Steven F.; Andersen, Henriette Skovgaard

    2012-01-01

    as a vulnerable exon and used patient derived lymphoblast cell lines and PAH minigenes to study the molecular defect that impacted pre-mRNA processing. We showed that the c.1144T>C and c.1066-3C>T mutations cause exon 11 skipping, while the c.1139C>T mutation is neutral or slightly beneficial. The c.1144T......-phenotype correlations. Therefore, recognizing such mutations enhances our ability to predict the BH(4)-response. Copyright © 2012 Elsevier Inc. All rights reserved. PMID:22698810[PubMed - in process]...

  5. NextSearch: A Search Engine for Mass Spectrometry Data against a Compact Nucleotide Exon Graph.

    Science.gov (United States)

    Kim, Hyunwoo; Park, Heejin; Paek, Eunok

    2015-07-02

    Proteogenomics research has been using six-frame translation of the whole genome or amino acid exon graphs to overcome the limitations of reference protein sequence database; however, six-frame translation is not suitable for annotating genes that span over multiple exons, and amino acid exon graphs are not convenient to represent novel splice variants and exon skipping events between exons of incompatible reading frames. We propose a proteogenomic pipeline NextSearch (Nucleotide EXon-graph Transcriptome Search) that is based on a nucleotide exon graph. This pipeline consists of constructing a compact nucleotide exon graph that systematically incorporates novel splice variations and a search tool that identifies peptides by directly searching the nucleotide exon graph against tandem mass spectra. Because our exon graph stores nucleotide sequences, it can easily represent novel splice variations and exon skipping events between incompatible reading frame exons. Searching for peptide identification is performed against this nucleotide exon graph, without converting it into a protein sequence in FASTA format, achieving an order of magnitude reduction in the size of the sequence database storage. NextSearch outputs the proteome-genome/transcriptome mapping results in a general feature format (GFF) file, which can be visualized by public tools such as the UCSC Genome Browser.

  6. Polymorphism of exon 3 of the HLA-G gene

    DEFF Research Database (Denmark)

    Hviid, T V; Meldgaard, Michael; Sørensen, S

    1997-01-01

    populations have only revealed a limited polymorphism. We investigated the polymorphism of the exon 3 of HLA-G by means of Polymerase Chain Reaction (PCR)-Single Strand Conformation Polymorphism (SSCP)- and DNA sequencing analysis in a Danish population. We detected four single-base substitutions in exon 3...... rate of embryos. HLA-G seems to play an important role in the feto-maternal relationship. The polymorphism of the HLA-G locus is not fully clarified. One study has shown extensive nucleotide sequence variation in the exon 3 (alpha-2 domain) in healthy African Americans. A few studies in other...... compared to the sequence of HLA-6.0 (G*01011); one of these has not been reported before. We also found a deletion of the first base of codon 130 or the third of codon 129 in a heterozygous individual. This study, together with previous results, suggests that the polymorphism of exon 3 of the HLA-G gene...

  7. Antisense mediated exon skipping therapy for duchenne muscular dystrophy (DMD)

    DEFF Research Database (Denmark)

    Brolin, Camilla; Shiraishi, Takehiko

    2011-01-01

    Duchenne Muscular Dystrophy (DMD) is a lethal disease caused by mutations in the dystrophin gene (DMD) that result in the absence of essential muscle protein dystrophin. Among many different approaches for DMD treatment, exon skipping, mediated by antisense oligonucleotides, is one of the most pr...... oligonucleotides (2'-O-methyl phosphorothioate (2OME-PS), phosphorodiamidate morpholino oligomer (PMO)) and peptide nucleic acid (PNA)....

  8. Translational and Regulatory Challenges for Exon Skipping Therapies

    NARCIS (Netherlands)

    Aartsma-Rus, Annemieke; Ferlini, Alessandra; Goemans, Nathalie; Pasmooij, Anna M. G.; Wells, Dominic J.; Bushby, Katerine; Vroom, Elizabeth; Balabanov, Pavel

    2014-01-01

    Several translational challenges are currently impeding the therapeutic development of antisense-mediated exon skipping approaches for rare diseases. Some of these are inherent to developing therapies for rare diseases, such as small patient numbers and limited information on natural history and int

  9. Exon duplications in the ATP7A gene

    DEFF Research Database (Denmark)

    Mogensen, Mie; Skjørringe, Tina; Kodama, Hiroko

    2011-01-01

    BACKGROUND: Menkes disease (MD) is an X-linked, fatal neurodegenerative disorder of copper metabolism, caused by mutations in the ATP7A gene. Thirty-three Menkes patients in whom no mutation had been detected with standard diagnostic tools were screened for exon duplications in the ATP7A gene...

  10. Deep RNA sequencing reveals the smallest known mitochondrial micro exon in animals: The placozoan cox1 single base pair exon.

    Science.gov (United States)

    Osigus, Hans-Jürgen; Eitel, Michael; Schierwater, Bernd

    2017-01-01

    The phylum Placozoa holds a key position for our understanding of the evolution of mitochondrial genomes in Metazoa. Placozoans possess large mitochondrial genomes which harbor several remarkable characteristics such as a fragmented cox1 gene and trans-splicing cox1 introns. A previous study also suggested the existence of cox1 mRNA editing in Trichoplax adhaerens, yet the only formally described species in the phylum Placozoa. We have analyzed RNA-seq data of the undescribed sister species, Placozoa sp. H2 ("Panama" clone), with special focus on the mitochondrial mRNA. While we did not find support for a previously postulated cox1 mRNA editing mechanism, we surprisingly found two independent transcripts representing intermediate cox1 mRNA splicing stages. Both transcripts consist of partial cox1 exon as well as overlapping intron fragments. The data suggest that the cox1 gene harbors a single base pair (cytosine) micro exon. Furthermore, conserved group I intron structures flank this unique micro exon also in other placozoans. We discuss the evolutionary origin of this micro exon in the context of a self-splicing intron gain in the cox1 gene of the last common ancestor of extant placozoans.

  11. Becker muscular dystrophy patients with deletions around exon 51; a promising outlook for exon skipping therapy in Duchenne patients.

    NARCIS (Netherlands)

    Helderman-van den Enden, A.T.; Straathof, C.S.; Aartsma-Rus, A.; Dunnen, J.T. den; Verbist, B.M.; Bakker, E.; Verschuuren, J.J.; Ginjaar, H.B.

    2010-01-01

    Theoretically, 13% of patients with Duchenne muscular dystrophy may benefit from antisense-mediated skipping of exon 51 to restore the reading frame, which results in the production of a shortened dystrophin protein. We give a detailed description with longitudinal follow up of three patients with B

  12. Antisense oligonucleotide induced exon skipping and the dystrophin gene transcript: cocktails and chemistries

    Directory of Open Access Journals (Sweden)

    Fletcher Sue

    2007-07-01

    Full Text Available Abstract Background Antisense oligonucleotides (AOs can interfere with exon recognition and intron removal during pre-mRNA processing, and induce excision of a targeted exon from the mature gene transcript. AOs have been used in vitro and in vivo to redirect dystrophin pre-mRNA processing in human and animal cells. Targeted exon skipping of selected exons in the dystrophin gene transcript can remove nonsense or frame-shifting mutations that would otherwise have lead to Duchenne Muscular Dystrophy, the most common childhood form of muscle wasting. Results Although many dystrophin exons can be excised using a single AO, several exons require two motifs to be masked for efficient or specific exon skipping. Some AOs were inactive when applied individually, yet pronounced exon excision was induced in transfected cells when the AOs were used in select combinations, clearly indicating synergistic rather than cumulative effects on splicing. The necessity for AO cocktails to induce efficient exon removal was observed with 2 different chemistries, 2'-O-methyl modified bases on a phosphorothioate backbone and phosphorodiamidate morpholino oligomers. Similarly, other trends in exon skipping, as a consequence of 2'-O-methyl AO action, such as removal of additional flanking exons or variations in exon skipping efficiency with overlapping AOs, were also seen when the corresponding sequences were prepared as phosphorodiamidate morpholino oligomers. Conclusion The combination of 2 AOs, directed at appropriate motifs in target exons was found to induce very efficient targeted exon skipping during processing of the dystrophin pre-mRNA. This combinatorial effect is clearly synergistic and is not influenced by the chemistry of the AOs used to induce exon excision. A hierarchy in exon skipping efficiency, observed with overlapping AOs composed of 2'-O-methyl modified bases, was also observed when these same sequences were evaluated as phosphorodiamidate morpholino

  13. Effect of Vitamin-B1 and Vitamin-B12 on the Growth and Carotenoid Content of Haematococcus pluvialis CH-1

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    Li-Xin Li

    2015-03-01

    Full Text Available An economic microalgae Haematococcus pluvialis CH-1 was used as experimental material. An experiment of adding six grades of concentrations of Vitamin-B1 and Vitamin-B12 respectively was conducted. Cell density, carotenoid content was measured. The results showed that the growth of H. pluvialis was accelerated significantly by adding of Vitamin-B1 and Vitamin-B12 respectively. The optimal adding concentration of Vitamin-B1 and Vitamin-B12 respectively for H. pluvialis was 10000 and 50 &mug/L. Under the optimal concentration for H. pluvialis cells density, carotenoid content were enhanced with Vitamin-B1: 20.1 and 21.3%; Vitamin-B12 : 29.5 and 24.4% higher than the blank respectively. On the mass culture of motile cells of H. pluvialis, properly adding Vitamin-B1 and Vitamin-B12 respectively was effective for increase cells density and carotenoid content.

  14. Effect of Vitamin-B12 and Vitamin-H on the Growth and Astaxanthin Content of Haematococcus Pluvialis CH-1

    Directory of Open Access Journals (Sweden)

    Li-xin Li

    2013-09-01

    Full Text Available An economic microalgae Haematococcus Pluvialis CH-1 was used as experimental material. An experiment of adding six grades of concentrations of Vitamin-B12 and Vitamin-H respectively was conducted. Cell density, biomass and astaxanthin content were measured. The results showed that the growth of H. Pluvialis was accelerated significantly by adding of Vitamin-B12 and Vitamin-H, respectively. The optimal adding concentration of Vitamin-B12 and Vitamin-H respectively for H. Pluvialis and 500 &mug/L. Under the optimal concentration for H. Pluvialis, cells density, biomass and astaxanthin content were enhanced with Vitamin-B12: 29.5, 30.0 and 28.3%; Vitamin-H: 17.1, 29.2 and 22.6% higher than the blank, respectively. On the mass culture of motile cells of H. Pluvialis, properly adding Vitamin-B12 and Vitamin-H, respectively was effective for increase cells density, biomass and astaxanthin content.

  15. Multiplex amplification of large sets of human exons.

    Science.gov (United States)

    Porreca, Gregory J; Zhang, Kun; Li, Jin Billy; Xie, Bin; Austin, Derek; Vassallo, Sara L; LeProust, Emily M; Peck, Bill J; Emig, Christopher J; Dahl, Fredrik; Gao, Yuan; Church, George M; Shendure, Jay

    2007-11-01

    A new generation of technologies is poised to reduce DNA sequencing costs by several orders of magnitude. But our ability to fully leverage the power of these technologies is crippled by the absence of suitable 'front-end' methods for isolating complex subsets of a mammalian genome at a scale that matches the throughput at which these platforms will routinely operate. We show that targeting oligonucleotides released from programmable microarrays can be used to capture and amplify approximately 10,000 human exons in a single multiplex reaction. Additionally, we show integration of this protocol with ultra-high-throughput sequencing for targeted variation discovery. Although the multiplex capture reaction is highly specific, we found that nonuniform capture is a key issue that will need to be resolved by additional optimization. We anticipate that highly multiplexed methods for targeted amplification will enable the comprehensive resequencing of human exons at a fraction of the cost of whole-genome resequencing.

  16. Evaluating the protein coding potential of exonized transposable element sequences

    Directory of Open Access Journals (Sweden)

    Borodovsky Mark

    2007-11-01

    Full Text Available Abstract Background Transposable element (TE sequences, once thought to be merely selfish or parasitic members of the genomic community, have been shown to contribute a wide variety of functional sequences to their host genomes. Analysis of complete genome sequences have turned up numerous cases where TE sequences have been incorporated as exons into mRNAs, and it is widely assumed that such 'exonized' TEs encode protein sequences. However, the extent to which TE-derived sequences actually encode proteins is unknown and a matter of some controversy. We have tried to address this outstanding issue from two perspectives: i-by evaluating ascertainment biases related to the search methods used to uncover TE-derived protein coding sequences (CDS and ii-through a probabilistic codon-frequency based analysis of the protein coding potential of TE-derived exons. Results We compared the ability of three classes of sequence similarity search methods to detect TE-derived sequences among data sets of experimentally characterized proteins: 1-a profile-based hidden Markov model (HMM approach, 2-BLAST methods and 3-RepeatMasker. Profile based methods are more sensitive and more selective than the other methods evaluated. However, the application of profile-based search methods to the detection of TE-derived sequences among well-curated experimentally characterized protein data sets did not turn up many more cases than had been previously detected and nowhere near as many cases as recent genome-wide searches have. We observed that the different search methods used were complementary in the sense that they yielded largely non-overlapping sets of hits and differed in their ability to recover known cases of TE-derived CDS. The probabilistic analysis of TE-derived exon sequences indicates that these sequences have low protein coding potential on average. In particular, non-autonomous TEs that do not encode protein sequences, such as Alu elements, are frequently

  17. A simple physical model predicts small exon length variations.

    Directory of Open Access Journals (Sweden)

    2006-04-01

    Full Text Available One of the most common splice variations are small exon length variations caused by the use of alternative donor or acceptor splice sites that are in very close proximity on the pre-mRNA. Among these, three-nucleotide variations at so-called NAGNAG tandem acceptor sites have recently attracted considerable attention, and it has been suggested that these variations are regulated and serve to fine-tune protein forms by the addition or removal of a single amino acid. In this paper we first show that in-frame exon length variations are generally overrepresented and that this overrepresentation can be quantitatively explained by the effect of nonsense-mediated decay. Our analysis allows us to estimate that about 50% of frame-shifted coding transcripts are targeted by nonsense-mediated decay. Second, we show that a simple physical model that assumes that the splicing machinery stochastically binds to nearby splice sites in proportion to the affinities of the sites correctly predicts the relative abundances of different small length variations at both boundaries. Finally, using the same simple physical model, we show that for NAGNAG sites, the difference in affinities of the neighboring sites for the splicing machinery accurately predicts whether splicing will occur only at the first site, splicing will occur only at the second site, or three-nucleotide splice variants are likely to occur. Our analysis thus suggests that small exon length variations are the result of stochastic binding of the spliceosome at neighboring splice sites. Small exon length variations occur when there are nearby alternative splice sites that have similar affinity for the splicing machinery.

  18. Detection of an exon 53 polymorphism in the dystrophin gene.

    Science.gov (United States)

    Prior, T W; Papp, A C; Snyder, P J; Sedra, M S

    1993-10-01

    We utilized a heteroduplex method to screen for small mutations in Duchenne muscular dystrophy patients who did not have deletions or duplications. A dystrophin exon 53 heteroduplex band was identified in 14.4% of the affected patients. Direct sequencing of the amplified product from DNA producing the heteroduplex revealed the presence of a polymorphism in the coding region. The codon for asparagine was converted from AAT to AAC.

  19. An Exon-Capture System for the Entire Class Ophiuroidea.

    Science.gov (United States)

    Hugall, Andrew F; O'Hara, Timothy D; Hunjan, Sumitha; Nilsen, Roger; Moussalli, Adnan

    2016-01-01

    Exon-capture studies have typically been restricted to relatively shallow phylogenetic scales due primarily to hybridization constraints. Here, we present an exon-capture system for an entire class of marine invertebrates, the Ophiuroidea, built upon a phylogenetically diverse transcriptome foundation. The system captures approximately 90% of the 1,552 exon target, across all major lineages of the quarter-billion-year-old extant crown group. Key features of our system are 1) basing the target on an alignment of orthologous genes determined from 52 transcriptomes spanning the phylogenetic diversity and trimmed to remove anything difficult to capture, map, or align; 2) use of multiple artificial representatives based on ancestral state reconstructions rather than exemplars to improve capture and mapping of the target; 3) mapping reads to a multi-reference alignment; and 4) using patterns of site polymorphism to distinguish among paralogy, polyploidy, allelic differences, and sample contamination. The resulting data give a well-resolved tree (currently standing at 417 samples, 275,352 sites, 91% data-complete) that will transform our understanding of ophiuroid evolution and biogeography.

  20. Variants affecting exon skipping contribute to complex traits.

    Directory of Open Access Journals (Sweden)

    Younghee Lee

    Full Text Available DNA variants that affect alternative splicing and the relative quantities of different gene transcripts have been shown to be risk alleles for some Mendelian diseases. However, for complex traits characterized by a low odds ratio for any single contributing variant, very few studies have investigated the contribution of splicing variants. The overarching goal of this study is to discover and characterize the role that variants affecting alternative splicing may play in the genetic etiology of complex traits, which include a significant number of the common human diseases. Specifically, we hypothesize that single nucleotide polymorphisms (SNPs in splicing regulatory elements can be characterized in silico to identify variants affecting splicing, and that these variants may contribute to the etiology of complex diseases as well as the inter-individual variability in the ratios of alternative transcripts. We leverage high-throughput expression profiling to 1 experimentally validate our in silico predictions of skipped exons and 2 characterize the molecular role of intronic genetic variations in alternative splicing events in the context of complex human traits and diseases. We propose that intronic SNPs play a role as genetic regulators within splicing regulatory elements and show that their associated exon skipping events can affect protein domains and structure. We find that SNPs we would predict to affect exon skipping are enriched among the set of SNPs reported to be associated with complex human traits.

  1. Rodent-specific alternative exons are more frequent in rapidly evolving genes and in paralogs

    Directory of Open Access Journals (Sweden)

    Mironov Andrey A

    2009-06-01

    Full Text Available Abstract Background Alternative splicing is an important mechanism for generating functional and evolutionary diversity of proteins in eukaryotes. Here, we studied the frequency and functionality of recently gained, rodent-specific alternative exons. Results We projected the data about alternative splicing of mouse genes to the rat, human, and dog genomes, and identified exons conserved in the rat genome, but missing in more distant genomes. We estimated the frequency of rodent-specific exons while controlling for possible residual conservation of spurious exons. The frequency of rodent-specific exons is higher among predominantly skipped exons and exons disrupting the reading frame. Separation of all genes by the rate of sequence evolution and by gene families has demonstrated that rodent-specific cassette exons are more frequent in rapidly evolving genes and in rodent-specific paralogs. Conclusion Thus we demonstrated that recently gained exons tend to occur in fast-evolving genes, and their inclusion rate tends to be lower than that of older exons. This agrees with the theory that gain of alternative exons is one of the major mechanisms of gene evolution.

  2. Therapeutic effects of exon skipping and losartan on skeletal muscle of mdx mice.

    Science.gov (United States)

    Lee, Eun-Joo; Kim, Ah-Young; Lee, Eun-Mi; Lee, Myeong-Mi; Min, Chang-Woo; Kang, Kyung-Ku; Park, Jin-Kyu; Hwang, Meeyul; Kwon, Soon-Hak; Tremblay, Jacques P; Jeong, Kyu-Shik

    2014-08-01

    Various attempts have been made to find treatments for Duchenne muscular dystrophy (DMD) patients. Exon skipping is one of the promising technologies for DMD treatment by restoring dystropin protein, which is one of the muscle components. It is well known that losartan, an angiotensin II type1 receptor blocker, promotes muscle regeneration and differentiation by lowering the level of transforming growth factor-beta1 signaling. In this study, we illustrated the combined effects of exon skipping and losartan on skeletal muscle of mdx mice. We supplied mdx mice with losartan for 2 weeks before exon skipping treatment. The losartan with the exon skipping group showed less expression of myf5 than the losartan treated group. Also the losartan with exon skipping group recovered normal muscle architecture, in contrast to the losartan group which still showed many central nuclei. However, the exon skipping efficiency and the restoration of dystrophin protein were lower in the losartan with exon skipping group compared to the exon skipping group. We reveal that losartan promotes muscle regeneration and shortens the time taken to restore normal muscle structure when combined with exon skipping. However, combined treatment of exon skipping and losartan decreases the restoration of dystrophin protein meaning decrease of exon skipping efficiency.

  3. Comparison of multiple vertebrate genomes reveals the birth and evolution of human exons.

    Science.gov (United States)

    Zhang, Xiang H-F; Chasin, Lawrence A

    2006-09-05

    Orthologous gene structures in eight vertebrate species were compared on a genomic scale to detect the birth and maturation of new internal exons during the course of evolution. We found that 40% of new human exons are alternatively spliced, and most of these are cassette exons (exons that are either included or skipped in their entirety) with low inclusion rates. This proportion decreases steadily as older and older exons are examined, even as splicing efficiency increases. Remarkably, the great majority of new cassette exons are composed of highly repeated sequences, especially Alu. Many new cassette exons are 5' untranslated exons; the proportion that code for protein increases steadily with age. New protein-coding exons evolve at a high rate, as evidenced by the initially high substitution rates (K(s) and K(a)), as well as the SNP density compared with older exons. This dynamic picture suggests that de novo recruitment rather than shuffling is the major route by which exons are added to genes, and that species-specific repeats could play a significant role in recent evolution.

  4. Multi-exon Skipping Using Cocktail Antisense Oligonucleotides in the Canine X-linked Muscular Dystrophy.

    Science.gov (United States)

    Miskew Nichols, Bailey; Aoki, Yoshitsugu; Kuraoka, Mutsuki; Lee, Joshua J A; Takeda, Shin'ichi; Yokota, Toshifumi

    2016-05-24

    Duchenne muscular dystrophy (DMD) is one of the most common lethal genetic diseases worldwide, caused by mutations in the dystrophin (DMD) gene. Exon skipping employs short DNA/RNA-like molecules called antisense oligonucleotides (AONs) that restore the reading frame and produce shorter but functional proteins. However, exon skipping therapy faces two major hurdles: limited applicability (up to only 13% of patients can be treated with a single AON drug), and uncertain function of truncated proteins. These issues were addressed with a cocktail AON approach. While approximately 70% of DMD patients can be treated by single exon skipping (all exons combined), one could potentially treat more than 90% of DMD patients if multiple exon skipping using cocktail antisense drugs can be realized. The canine X-linked muscular dystrophy (CXMD) dog model, whose phenotype is more similar to human DMD patients, was used to test the systemic efficacy and safety of multi-exon skipping of exons 6 and 8. The CXMD dog model harbors a splice site mutation in intron 6, leading to a lack of exon 7 in dystrophin mRNA. To restore the reading frame in CXMD requires multi-exon skipping of exons 6 and 8; therefore, CXMD is a good middle-sized animal model for testing the efficacy and safety of multi-exon skipping. In the current study, a cocktail of antisense morpholinos targeting exon 6 and exon 8 was designed and it restored dystrophin expression in body-wide skeletal muscles. Methods for transfection/injection of cocktail oligos and evaluation of the efficacy and safety of multi-exon skipping in the CXMD dog model are presented.

  5. Increased frequency of co-existing JAK2 exon-12 or MPL exon-10 mutations in patients with low JAK2(V617F) allelic burden.

    Science.gov (United States)

    Nussenzveig, Roberto H; Pham, Ha T; Perkins, Sherrie L; Prchal, Josef T; Agarwal, Archana M; Salama, Mohamed E

    2016-01-01

    The frequency of co-existing JAK2(V617F)/MPL and JAK2(V617F)/JAK2 exon-12 mutations has not been previously investigated in MPNs. Poor survival was reported in primary myelofibrosis with low JAK2(V617F) allelic burden. However, mutational status of JAK2 exon-12 or MPL were not reported in these patients. This study developed a cost-effective multiplex high resolution melt assay that screens for mutations in JAK2 gene exons-12 and -14 ((V617F)) and MPL gene exon-10. Co-existing mutations with JAK2(V617F) were detected in 2.9% (6/208; two JAK2 exon-12 and four MPL exon-10) patient specimens with known JAK2(V617F) (allelic-burden range: 0.1-96.8%). Co-existing mutations were detected in specimens with < 12% JAK2(V617F) allelic burden. Current WHO guidelines do not recommend further testing once JAK2(V617F) mutation is detected in MPNs. The findings, however, indicate that quantification of JAK2(V617F) allele burden may be clinically relevant in MPNs and in those with low allelic burden additional testing for JAK2 exon-12 and MPL exon-10 mutation should be pursued.

  6. Functional analysis of a large set of BRCA2 exon 7 variants highlights the predictive value of hexamer scores in detecting alterations of exonic splicing regulatory elements.

    Science.gov (United States)

    Di Giacomo, Daniela; Gaildrat, Pascaline; Abuli, Anna; Abdat, Julie; Frébourg, Thierry; Tosi, Mario; Martins, Alexandra

    2013-11-01

    Exonic variants can alter pre-mRNA splicing either by changing splice sites or by modifying splicing regulatory elements. Often these effects are difficult to predict and are only detected by performing RNA analyses. Here, we analyzed, in a minigene assay, 26 variants identified in the exon 7 of BRCA2, a cancer predisposition gene. Our results revealed eight new exon skipping mutations in this exon: one directly altering the 5' splice site and seven affecting potential regulatory elements. This brings the number of splicing regulatory mutations detected in BRCA2 exon 7 to a total of 11, a remarkably high number considering the total number of variants reported in this exon (n = 36), all tested in our minigene assay. We then exploited this large set of splicing data to test the predictive value of splicing regulator hexamers' scores recently established by Ke et al. (). Comparisons of hexamer-based predictions with our experimental data revealed high sensitivity in detecting variants that increased exon skipping, an important feature for prescreening variants before RNA analysis. In conclusion, hexamer scores represent a promising tool for predicting the biological consequences of exonic variants and may have important applications for the interpretation of variants detected by high-throughput sequencing.

  7. A founder synonymous COL7A1 mutation in three Danish families with dominant dystrophic epidermolysis bullosa pruriginosa identifies exonic regulatory sequences required for exon 87 splicing

    DEFF Research Database (Denmark)

    Covaciu, C; Grosso, F; Pisaneschi, E

    2011-01-01

    a previously unrecognized translationally silent exonic COL7A1 mutation that results in skipping of exon 87 and is associated with DDEB-Pr phenotypes in several members of three apparently unrelated Danish families. A haplotype segregation study suggested a common ancestor in these kindred. Functional splicing...... shoulders. DEB-Pr is caused by either dominant (DDEB-Pr) or recessive mutations in the COL7A1 gene encoding type VII collagen (COLVII). The full spectrum of COL7A1 mutations in DEB-Pr remains elusive and the genotype-phenotype correlation is largely incomplete. Here, we report and functionally characterize...... analysis of the mutant exon by a COL7A1 minigene construct and computational prediction for splicing regulatory cis-sequences prove that the mutation alters the activity of an exonic splicing enhancer (ESE) critical for exon inclusion. These findings substantiate for the first time the involvement...

  8. Reversible optic neuropathy with OPA1 exon 5b mutation

    DEFF Research Database (Denmark)

    Cornille, K.; Milea, D.; Amati-Bonneau, P.

    2008-01-01

    A new c.740G>A (R247H) mutation in OPA1 alternate spliced exon 5b was found in a patient presenting with bilateral optic neuropathy followed by partial, spontaneous visual recovery. R247H fibroblasts from the patient and his unaffected father presented unusual highly tubular mitochondrial network......, significant increased susceptibility to apoptosis, oxidative phosphorylation uncoupling, and altered OPA1 protein profile, supporting the pathogenicity of this mutation. These results suggest that the clinical spectrum of the OPA1-associated optic neuropathies may be larger than previously described...

  9. Evidence for a novel exon in the coding region of the adenomatous polyposis coli (APC) gene

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Ling; St. Denis, K.A.; Bapat, B. [Univ. of Toronto (Canada)

    1995-08-10

    Germline mutations of the tumor suppressor gene APC cause familial adenomatous polyposis. Somatic APC alterations are involved in several sporadic neoplasma, including colorectal, duodenal, gastric, and esophageal carcinoma. The APC mRNA is encoded by 15 exons. Additional transcripts have been reported, due to alternative splicing of coding as well as noncoding regions. Two mRNA isoforms occur due to a deletion of exon 7 or a partial deletion of exon 9. We have identified a novel exon, flanked by APC exons 10 and 11, which is expressed as an alternatively transcribed product of the gene. Further, we have shown that the novel exon consists of a heptad repeat motif and is conserved across species. 18 refs., 2 figs.

  10. TALE-directed local modulation of H3K9 methylation shapes exon recognition.

    Science.gov (United States)

    Bieberstein, Nicole I; Kozáková, Eva; Huranová, Martina; Thakur, Prasoon K; Krchňáková, Zuzana; Krausová, Michaela; Carrillo Oesterreich, Fernando; Staněk, David

    2016-07-21

    In search for the function of local chromatin environment on pre-mRNA processing we established a new tool, which allows for the modification of chromatin using a targeted approach. Using Transcription Activator-Like Effector domains fused to histone modifying enzymes (TALE-HME), we show locally restricted alteration of histone methylation modulates the splicing of target exons. We provide evidence that a local increase in H3K9 di- and trimethylation promotes inclusion of the target alternative exon, while demethylation by JMJD2D leads to exon skipping. We further demonstrate that H3K9me3 is localized on internal exons genome-wide suggesting a general role in splicing. Consistently, targeting of the H3K9 demethylase to a weak constitutive exon reduced co-transcriptional splicing. Together our data show H3K9 methylation within the gene body is a factor influencing recognition of both constitutive and alternative exons.

  11. Polymorphisms of exon 5, exon 7 and intron 10 of MMP2 gene and their association with wool density in Rex rabbits

    Directory of Open Access Journals (Sweden)

    S.J. Chen

    2017-06-01

    Full Text Available Wool density is an important index that influences Rex rabbit fur quality. In our earlier studies, we found some important differentially expressed genes in different wool density of Rex rabbit by cDNA microarray. Based on the outcome, we conducted an association study to identify single nucleotide polymorphisms (SNPs of exon 1, 5, 7 and 10 of matrix metalloproteinase-2 (MMP2 gene and their ligands associated with wool density. The results showed that exon 1 and exon 10 of MMP2 gene did not occur mutation in 100 Rex rabbits, meanwhile 3 SNPs were identified in exon 5, exon 7 and intron 10 of MMP2 gene sequence respectively, the 3 mutation sites were as follows: MMP2-exon 5-26C/G, MMP2-exon 7-101C/T and MMP2-intron 10-6C/T. The 3 SNPs were all in Hardy-Weinberg equilibrium. Phenotypic correlation analysis results showed the 3 mutations lacked significant associations (P>0.05 with the wool density.

  12. Four parameters increase the sensitivity and specificity of the exon array analysis and disclose 25 novel aberrantly spliced exons in myotonic dystrophy.

    Science.gov (United States)

    Yamashita, Yoshihiro; Matsuura, Tohru; Shinmi, Jun; Amakusa, Yoshinobu; Masuda, Akio; Ito, Mikako; Kinoshita, Masanobu; Furuya, Hirokazu; Abe, Koji; Ibi, Tohru; Sahashi, Ko; Sahashi, Koo; Ohno, Kinji

    2012-06-01

    Myotonic dystrophy type 1 (DM1) is an RNA gain-of-function disorder in which abnormally expanded CTG repeats of DMPK sequestrate a splicing trans-factor MBNL1 and upregulate another splicing trans-factor CUGBP1. To identify a diverse array of aberrantly spliced genes, we performed the exon array analysis of DM1 muscles. We analyzed 72 exons by RT-PCR and found that 27 were aberrantly spliced, whereas 45 were not. Among these, 25 were novel and especially splicing aberrations of LDB3 exon 4 and TTN exon 45 were unique to DM1. Retrospective analysis revealed that four parameters efficiently detect aberrantly spliced exons: (i) the signal intensity is high; (ii) the ratio of probe sets with reliable signal intensities (that is, detection above background P-value=0.000) is high within a gene; (iii) the splice index (SI) is high; and (iv) SI is deviated from SIs of the other exons that can be estimated by calculating the deviation value (DV). Application of the four parameters gave rise to a sensitivity of 77.8% and a specificity of 95.6% in our data set. We propose that calculation of DV, which is unique to our analysis, is of particular importance in analyzing the exon array data.

  13. Biased exonization of transposed elements in duplicated genes: A lesson from the TIF-IA gene

    Directory of Open Access Journals (Sweden)

    Shomron Noam

    2007-11-01

    Full Text Available Abstract Background Gene duplication and exonization of intronic transposed elements are two mechanisms that enhance genomic diversity. We examined whether there is less selection against exonization of transposed elements in duplicated genes than in single-copy genes. Results Genome-wide analysis of exonization of transposed elements revealed a higher rate of exonization within duplicated genes relative to single-copy genes. The gene for TIF-IA, an RNA polymerase I transcription initiation factor, underwent a humanoid-specific triplication, all three copies of the gene are active transcriptionally, although only one copy retains the ability to generate the TIF-IA protein. Prior to TIF-IA triplication, an Alu element was inserted into the first intron. In one of the non-protein coding copies, this Alu is exonized. We identified a single point mutation leading to exonization in one of the gene duplicates. When this mutation was introduced into the TIF-IA coding copy, exonization was activated and the level of the protein-coding mRNA was reduced substantially. A very low level of exonization was detected in normal human cells. However, this exonization was abundant in most leukemia cell lines evaluated, although the genomic sequence is unchanged in these cancerous cells compared to normal cells. Conclusion The definition of the Alu element within the TIF-IA gene as an exon is restricted to certain types of cancers; the element is not exonized in normal human cells. These results further our understanding of the delicate interplay between gene duplication and alternative splicing and of the molecular evolutionary mechanisms leading to genetic innovations. This implies the existence of purifying selection against exonization in single copy genes, with duplicate genes free from such constrains.

  14. Lex-SVM: exploring the potential of exon expression profiling for disease classification.

    Science.gov (United States)

    Yuan, Xiongying; Zhao, Yi; Liu, Changning; Bu, Dongbo

    2011-04-01

    Exon expression profiling technologies, including exon arrays and RNA-Seq, measure the abundance of every exon in a gene. Compared with gene expression profiling technologies like 3' array, exon expression profiling technologies could detect alterations in both transcription and alternative splicing, therefore they are expected to be more sensitive in diagnosis. However, exon expression profiling also brings higher dimension, more redundancy, and significant correlation among features. Ignoring the correlation structure among exons of a gene, a popular classification method like L1-SVM selects exons individually from each gene and thus is vulnerable to noise. To overcome this limitation, we present in this paper a new variant of SVM named Lex-SVM to incorporate correlation structure among exons and known splicing patterns to promote classification performance. Specifically, we construct a new norm, ex-norm, including our prior knowledge on exon correlation structure to regularize the coefficients of a linear SVM. Lex-SVM can be solved efficiently using standard linear programming techniques. The advantage of Lex-SVM is that it can select features group-wisely, force features in a subgroup to take equal weihts and exclude the features that contradict the majority in the subgroup. Experimental results suggest that on exon expression profile, Lex-SVM is more accurate than existing methods. Lex-SVM also generates a more compact model and selects genes more consistently in cross-validation. Unlike L1-SVM selecting only one exon in a gene, Lex-SVM assigns equal weights to as many exons in a gene as possible, lending itself easier for further interpretation.

  15. Genomic V exons from whole genome shotgun data in reptiles.

    Science.gov (United States)

    Olivieri, D N; von Haeften, B; Sánchez-Espinel, C; Faro, J; Gambón-Deza, F

    2014-08-01

    Reptiles and mammals diverged over 300 million years ago, creating two parallel evolutionary lineages amongst terrestrial vertebrates. In reptiles, two main evolutionary lines emerged: one gave rise to Squamata, while the other gave rise to Testudines, Crocodylia, and Aves. In this study, we determined the genomic variable (V) exons from whole genome shotgun sequencing (WGS) data in reptiles corresponding to the three main immunoglobulin (IG) loci and the four main T cell receptor (TR) loci. We show that Squamata lack the TRG and TRD genes, and snakes lack the IGKV genes. In representative species of Testudines and Crocodylia, the seven major IG and TR loci are maintained. As in mammals, genes of the IG loci can be grouped into well-defined IMGT clans through a multi-species phylogenetic analysis. We show that the reptilian IGHV and IGLV genes are distributed amongst the established mammalian clans, while their IGKV genes are found within a single clan, nearly exclusive from the mammalian sequences. The reptilian and mammalian TRAV genes cluster into six common evolutionary clades (since IMGT clans have not been defined for TR). In contrast, the reptilian TRBV genes cluster into three clades, which have few mammalian members. In this locus, the V exon sequences from mammals appear to have undergone different evolutionary diversification processes that occurred outside these shared reptilian clans. These sequences can be obtained in a freely available public repository (http://vgenerepertoire.org).

  16. Single nucleotide polymorphism-based validation of exonic splicing enhancers.

    Directory of Open Access Journals (Sweden)

    William G Fairbrother

    2004-09-01

    Full Text Available Because deleterious alleles arising from mutation are filtered by natural selection, mutations that create such alleles will be underrepresented in the set of common genetic variation existing in a population at any given time. Here, we describe an approach based on this idea called VERIFY (variant elimination reinforces functionality, which can be used to assess the extent of natural selection acting on an oligonucleotide motif or set of motifs predicted to have biological activity. As an application of this approach, we analyzed a set of 238 hexanucleotides previously predicted to have exonic splicing enhancer (ESE activity in human exons using the relative enhancer and silencer classification by unanimous enrichment (RESCUE-ESE method. Aligning the single nucleotide polymorphisms (SNPs from the public human SNP database to the chimpanzee genome allowed inference of the direction of the mutations that created present-day SNPs. Analyzing the set of SNPs that overlap RESCUE-ESE hexamers, we conclude that nearly one-fifth of the mutations that disrupt predicted ESEs have been eliminated by natural selection (odds ratio = 0.82 +/- 0.05. This selection is strongest for the predicted ESEs that are located near splice sites. Our results demonstrate a novel approach for quantifying the extent of natural selection acting on candidate functional motifs and also suggest certain features of mutations/SNPs, such as proximity to the splice site and disruption or alteration of predicted ESEs, that should be useful in identifying variants that might cause a biological phenotype.

  17. Deletion of ameloblastin exon 6 is associated with amelogenesis imperfecta.

    Science.gov (United States)

    Poulter, James A; Murillo, Gina; Brookes, Steven J; Smith, Claire E L; Parry, David A; Silva, Sandra; Kirkham, Jennifer; Inglehearn, Chris F; Mighell, Alan J

    2014-10-15

    Amelogenesis imperfecta (AI) describes a heterogeneous group of inherited dental enamel defects reflecting failure of normal amelogenesis. Ameloblastin (AMBN) is the second most abundant enamel matrix protein expressed during amelogenesis. The pivotal role of AMBN in amelogenesis has been confirmed experimentally using mouse models. However, no AMBN mutations have been associated with human AI. Using autozygosity mapping and exome sequencing, we identified genomic deletion of AMBN exon 6 in a second cousin consanguineous family with three of the six children having hypoplastic AI. The genomic deletion corresponds to an in-frame deletion of 79 amino acids, shortening the protein from 447 to 368 residues. Exfoliated primary teeth (unmatched to genotype) were available from family members. The most severely affected had thin, aprismatic enamel (similar to that reported in mice homozygous for Ambn lacking exons 5 and 6). Other teeth exhibited thicker but largely aprismatic enamel. One tooth had apparently normal enamel. It has been suggested that AMBN may function in bone development. No clinically obvious bone or other co-segregating health problems were identified in the family investigated. This study confirms for the first time that AMBN mutations cause non-syndromic human AI and that mouse models with disrupted Ambn function are valid.

  18. Exon Shuffling and Origin of Scorpion Venom Biodiversity

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    Xueli Wang

    2016-12-01

    Full Text Available Scorpion venom is a complex combinatorial library of peptides and proteins with multiple biological functions. A combination of transcriptomic and proteomic techniques has revealed its enormous molecular diversity, as identified by the presence of a large number of ion channel-targeted neurotoxins with different folds, membrane-active antimicrobial peptides, proteases, and protease inhibitors. Although the biodiversity of scorpion venom has long been known, how it arises remains unsolved. In this work, we analyzed the exon-intron structures of an array of scorpion venom protein-encoding genes and unexpectedly found that nearly all of these genes possess a phase-1 intron (one intron located between the first and second nucleotides of a codon near the cleavage site of a signal sequence despite their mature peptides remarkably differ. This observation matches a theory of exon shuffling in the origin of new genes and suggests that recruitment of different folds into scorpion venom might be achieved via shuffling between body protein-coding genes and ancestral venom gland-specific genes that presumably contributed tissue-specific regulatory elements and secretory signal sequences.

  19. Evolutionary characteristics of exons expressed at different abundance levels in mammals

    Institute of Scientific and Technical Information of China (English)

    YU HaiJing; FANG Lin; LI Xin; ZHANG XiaoYan; YE Jia; LI Jie; HU WeiHong; ZHENG BingRong; XIAO ChunJie

    2009-01-01

    With comparative genomics approaches, we evaluated the evolutionary characteristics of conservation of exons which are expressed abundantly, moderately or lowly in mammals. Using non-coding regions and pseudogenes as controls, sequence identity, phastCons and Ka/Ks analyses were carried out and our results showed that as the exons of high abundance are highly conserved, the minor and low exons also showed conservative characteristics in evolution. Our findings suggested that the exons with less abundance which constitute a large proportion of distinct species in transcriptome of organisms are under functional constraint and might play certain roles in enriching biological complexity in the evolution of organisms.

  20. The effects of multiple features of alternatively spliced exons on the KA/KS ratio test

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    Chen Feng-Chi

    2006-05-01

    Full Text Available Abstract Background The evolution of alternatively spliced exons (ASEs is of primary interest because these exons are suggested to be a major source of functional diversity of proteins. Many exon features have been suggested to affect the evolution of ASEs. However, previous studies have relied on the KA/KS ratio test without taking into consideration information sufficiency (i.e., exon length > 75 bp, cross-species divergence > 5% of the studied exons, leading to potentially biased interpretations. Furthermore, which exon feature dominates the results of the KA/KS ratio test and whether multiple exon features have additive effects have remained unexplored. Results In this study, we collect two different datasets for analysis – the ASE dataset (which includes lineage-specific ASEs and conserved ASEs and the ACE dataset (which includes only conserved ASEs. We first show that information sufficiency can significantly affect the interpretation of relationship between exons features and the KA/KS ratio test results. After discarding exons with insufficient information, we use a Boolean method to analyze the relationship between test results and four exon features (namely length, protein domain overlapping, inclusion level, and exonic splicing enhancer (ESE frequency for the ASE dataset. We demonstrate that length and protein domain overlapping are dominant factors, and they have similar impacts on test results of ASEs. In addition, despite the weak impacts of inclusion level and ESE motif frequency when considered individually, combination of these two factors still have minor additive effects on test results. However, the ACE dataset shows a slightly different result in that inclusion level has a marginally significant effect on test results. Lineage-specific ASEs may have contributed to the difference. Overall, in both ASEs and ACEs, protein domain overlapping is the most dominant exon feature while ESE frequency is the weakest one in affecting

  1. Naturally occuring nucleosome positioning signals in human exons and introns

    DEFF Research Database (Denmark)

    Baldi, Pierre; Brunak, Søren; Chauvin, Yves;

    1996-01-01

    alignments of internal exon and intron sequences corresponds to a periodic "in phase" bending potential towards the major groove of the DNA. The nucleosome positioning data show that the consensus triplets (and their complements) have a preference for locations on a bent double helix where the major groove...... of roughly ten nucleotides. The periodic pattern is also present in intron sequences, although the strength per nucleotide is weaker. Using two independent profile methods based on triplet bendability parameters from DNase I experiments and nucleosome positioning data, we show that the pattern in multiple...... faces inward and is compressed. The in-phase triplets are located adjacent to GCC/GGC triplets known to have the strongest bias in their positioning on the nucleosome. Analysis of mRNA sequences encoding proteins with known tertiary structure exclude the possibility that the pattern is a consequence...

  2. Exonic variants associated with development of aspirin exacerbated respiratory diseases.

    Directory of Open Access Journals (Sweden)

    Seung-Woo Shin

    Full Text Available Aspirin-exacerbated respiratory disease (AERD is one phenotype of asthma, often occurring in the form of a severe and sudden attack. Due to the time-consuming nature and difficulty of oral aspirin challenge (OAC for AERD diagnosis, non-invasive biomarkers have been sought. The aim of this study was to identify AERD-associated exonic SNPs and examine the diagnostic potential of a combination of these candidate SNPs to predict AERD. DNA from 165 AERD patients, 397 subjects with aspirin-tolerant asthma (ATA, and 398 normal controls were subjected to an Exome BeadChip assay containing 240K SNPs. 1,023 models (210-1 were generated from combinations of the top 10 SNPs, selected by the p-values in association with AERD. The area under the curve (AUC of the receiver operating characteristic (ROC curves was calculated for each model. SNP Function Portal and PolyPhen-2 were used to validate the functional significance of candidate SNPs. An exonic SNP, exm537513 in HLA-DPB1, showed the lowest p-value (p = 3.40×10-8 in its association with AERD risk. From the top 10 SNPs, a combination model of 7 SNPs (exm537513, exm83523, exm1884673, exm538564, exm2264237, exm396794, and exm791954 showed the best AUC of 0.75 (asymptotic p-value of 7.94×10-21, with 34% sensitivity and 93% specificity to discriminate AERD from ATA. Amino acid changes due to exm83523 in CHIA were predicted to be "probably damaging" to the structure and function of the protein, with a high score of '1'. A combination model of seven SNPs may provide a useful, non-invasive genetic marker combination for predicting AERD.

  3. Novel exon of mammalian ADAR2 extends open reading frame.

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    Stefan Maas

    Full Text Available BACKGROUND: The post-transcriptional processing of pre-mRNAs by RNA editing contributes significantly to the complexity of the mammalian transcriptome. RNA editing by site-selective A-to-I modification also regulates protein function through recoding of genomically specified sequences. The adenosine deaminase ADAR2 is the main enzyme responsible for recoding editing and loss of ADAR2 function in mice leads to a phenotype of epilepsy and premature death. Although A-to-I RNA editing is known to be subject to developmental and cell-type specific regulation, there is little knowledge regarding the mechanisms that regulate RNA editing in vivo. Therefore, the characterization of ADAR expression and identification of alternative ADAR variants is an important prerequisite for understanding the mechanisms for regulation of RNA editing and the causes for deregulation in disease. METHODOLOGY/PRINCIPAL FINDINGS: Here we present evidence for a new ADAR2 splice variant that extends the open reading frame of ADAR2 by 49 amino acids through the utilization of an exon located 18 kilobases upstream of the previously annotated first coding exon and driven by a candidate alternative promoter. Interestingly, the 49 amino acid extension harbors a sequence motif that is closely related to the R-domain of ADAR3 where it has been shown to function as a basic, single-stranded RNA binding domain. Quantitative expression analysis shows that expression of the novel ADAR2 splice variant is tissue specific being highest in the cerebellum. CONCLUSIONS/SIGNIFICANCE: The strong sequence conservation of the ADAR2 R-domain between human, mouse and rat ADAR2 genes suggests a conserved function for this isoform of the RNA editing enzyme.

  4. The role of exon shuffling in shaping protein-protein interaction networks

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    França Gustavo S

    2010-12-01

    Full Text Available Abstract Background Physical protein-protein interaction (PPI is a critical phenomenon for the function of most proteins in living organisms and a significant fraction of PPIs are the result of domain-domain interactions. Exon shuffling, intron-mediated recombination of exons from existing genes, is known to have been a major mechanism of domain shuffling in metazoans. Thus, we hypothesized that exon shuffling could have a significant influence in shaping the topology of PPI networks. Results We tested our hypothesis by compiling exon shuffling and PPI data from six eukaryotic species: Homo sapiens, Mus musculus, Drosophila melanogaster, Caenorhabditis elegans, Cryptococcus neoformans and Arabidopsis thaliana. For all four metazoan species, genes enriched in exon shuffling events presented on average higher vertex degree (number of interacting partners in PPI networks. Furthermore, we verified that a set of protein domains that are simultaneously promiscuous (known to interact to multiple types of other domains, self-interacting (able to interact with another copy of themselves and abundant in the genomes presents a stronger signal for exon shuffling. Conclusions Exon shuffling appears to have been a recurrent mechanism for the emergence of new PPIs along metazoan evolution. In metazoan genomes, exon shuffling also promoted the expansion of some protein domains. We speculate that their promiscuous and self-interacting properties may have been decisive for that expansion.

  5. Unusual intron conservation near tissue-regulated exons found by splicing microarrays.

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    Charles W Sugnet

    2006-01-01

    Full Text Available Alternative splicing contributes to both gene regulation and protein diversity. To discover broad relationships between regulation of alternative splicing and sequence conservation, we applied a systems approach, using oligonucleotide microarrays designed to capture splicing information across the mouse genome. In a set of 22 adult tissues, we observe differential expression of RNA containing at least two alternative splice junctions for about 40% of the 6,216 alternative events we could detect. Statistical comparisons identify 171 cassette exons whose inclusion or skipping is different in brain relative to other tissues and another 28 exons whose splicing is different in muscle. A subset of these exons is associated with unusual blocks of intron sequence whose conservation in vertebrates rivals that of protein-coding exons. By focusing on sets of exons with similar regulatory patterns, we have identified new sequence motifs implicated in brain and muscle splicing regulation. Of note is a motif that is strikingly similar to the branchpoint consensus but is located downstream of the 5' splice site of exons included in muscle. Analysis of three paralogous membrane-associated guanylate kinase genes reveals that each contains a paralogous tissue-regulated exon with a similar tissue inclusion pattern. While the intron sequences flanking these exons remain highly conserved among mammalian orthologs, the paralogous flanking intron sequences have diverged considerably, suggesting unusually complex evolution of the regulation of alternative splicing in multigene families.

  6. JAK2 exon 12 mutations in patients with Philadelphia(Ph) chromosome-negative myeloproliferative neoplasms

    Institute of Scientific and Technical Information of China (English)

    王婕妤

    2012-01-01

    Objective To investigate JAK2 exon 12 mutations in patients with Philadelphia (Ph) chromosome-negative myeloproliferative neoplasms (MPN) and the clinical characteristics of patients with JAK2 exon 12 mutants. Methods Allele-specific PCR(AS-PCR) was applied to identify JAK2 V617F mutation.

  7. Fourier Power Spectrum Analysis of Exons for the Period-3 Behavior

    Institute of Scientific and Technical Information of China (English)

    Yuan Xin TIAN; Chao CHEN; Xiao Yong ZOU; Jian Ding QIU; Pei Xiang CAI; Jin Yuan MO

    2005-01-01

    The period-3 behaviors of 105 exons from 20 genes in human were studied by Fourier power spectrum. The results indicated that not all exons show the period-3 behavior. The exons were adjusted in order to make them accord with the order of the protein translated, and we found that the period-3 character is relation to the length of exons and the bases distribution in the three codon position. Furthermore, as long as the exons with period-3 behavior accord with the order of protein translated, they would exhibit the synonymous codons usage preference, and the codons with g/c at the third position are used in higher frequency. The results are significant to the gene prediction and the research on the introns.

  8. Exon 44 nonsense mutation in two-Duchenne muscular dystrophy brothers detected by heteroduplex analysis.

    Science.gov (United States)

    Prior, T W; Papp, A C; Snyder, P J; Burghes, A H; Sedra, M S; Western, L M; Bartolo, C; Mendell, J R

    1993-01-01

    Utilizing a heteroduplex method, we screened the dystrophin exon 43-45 region for point mutations, including small deletions and insertions. The method depends upon the formation of a heteroduplex between wild-type and mutant DNA PCR products. DNA specimens from one hundred and four DMD patients without detected deletions or duplications were multiplexed amplified for exons 43, 44, and 45. The PCR products were mixed with the PCR products from nonaffected controls, electrophoresed, and examined for the presence of altered mobility heteroduplex bands. An exon 44 nonsense mutation in two DMD brothers and a common intron 44 polymorphism were identified using this approach. Although the exon 44-45 region is a hotspot for deletion breakpoints, it does not appear to be prone to point mutations. The technique is extremely useful for screening several exons simultaneously and it allowed us to screen a large number of patients.

  9. CoNVaDING: Single Exon Variation Detection in Targeted NGS Data.

    Science.gov (United States)

    Johansson, Lennart F; van Dijk, Freerk; de Boer, Eddy N; van Dijk-Bos, Krista K; Jongbloed, Jan D H; van der Hout, Annemieke H; Westers, Helga; Sinke, Richard J; Swertz, Morris A; Sijmons, Rolf H; Sikkema-Raddatz, Birgit

    2016-05-01

    We have developed a tool for detecting single exon copy-number variations (CNVs) in targeted next-generation sequencing data: CoNVaDING (Copy Number Variation Detection In Next-generation sequencing Gene panels). CoNVaDING includes a stringent quality control (QC) metric, that excludes or flags low-quality exons. Since this QC shows exactly which exons can be reliably analyzed and which exons are in need of an alternative analysis method, CoNVaDING is not only useful for CNV detection in a research setting, but also in clinical diagnostics. During the validation phase, CoNVaDING detected all known CNVs in high-quality targets in 320 samples analyzed, giving 100% sensitivity and 99.998% specificity for 308,574 exons. CoNVaDING outperforms existing tools by exhibiting a higher sensitivity and specificity and by precisely identifying low-quality samples and regions.

  10. The proximal first exon architecture of the murine ghrelin gene is highly similar to its human orthologue

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    Seim Inge

    2009-05-01

    Full Text Available Abstract Background The murine ghrelin gene (Ghrl, originally sequenced from stomach tissue, contains five exons and a single transcription start site in a short, 19 bp first exon (exon 0. We recently isolated several novel first exons of the human ghrelin gene and found evidence of a complex transcriptional repertoire. In this report, we examined the 5' exons of the murine ghrelin orthologue in a range of tissues using 5' RACE. Findings 5' RACE revealed two transcription start sites (TSSs in exon 0 and four TSSs in intron 0, which correspond to 5' extensions of exon 1. Using quantitative, real-time RT-PCR (qRT-PCR, we demonstrated that extended exon 1 containing Ghrl transcripts are largely confined to the spleen, adrenal gland, stomach, and skin. Conclusion We demonstrate that multiple transcription start sites are present in exon 0 and an extended exon 1 of the murine ghrelin gene, similar to the proximal first exon organisation of its human orthologue. The identification of several transcription start sites in intron 0 of mouse ghrelin (resulting in an extension of exon 1 raises the possibility that developmental-, cell- and tissue-specific Ghrl mRNA species are created by employing alternative promoters and further studies of the murine ghrelin gene are warranted.

  11. Evolutionary constraint helps unmask a splicing regulatory region in BRCA1 exon 11.

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    Michela Raponi

    Full Text Available BACKGROUND: Alternative splicing across exon 11 produces several BRCA1 isoforms. Their proportion varies during the cell cycle, between tissues and in cancer suggesting functional importance of BRCA1 splicing regulation around this exon. Although the regulatory elements driving exon 11 splicing have never been identified, a selective constraint against synonymous substitutions (silent nucleotide variations that do not alter the amino acid residue sequence in a critical region of BRCA1 exon 11 has been reported to be associated with the necessity to maintain regulatory sequences. METHODOLOGY/PRINCIPAL FINDINGS: Here we have designed a specific minigene to investigate the possibility that this bias in synonymous codon usage reflects the need to preserve the BRCA1 alternative splicing program. We report that in-frame deletions and translationally silent nucleotide substitutions in the critical region affect splicing regulation of BRCA1 exon 11. CONCLUSIONS/SIGNIFICANCE: Using a hybrid minigene approach, we have experimentally validated the hypothesis that the need to maintain correct alternative splicing is a selective pressure against translationally silent sequence variations in the critical region of BRCA1 exon 11. Identification of the trans-acting factors involved in regulating exon 11 alternative splicing will be important in understanding BRCA1-associated tumorigenesis.

  12. Exon skipping and Duchenne muscular dystrophy: Hope, hype and how feasible?

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    Wilton Steve

    2008-01-01

    Full Text Available Duchenne muscular dystrophy (DMD, the most common and serious form of childhood muscle wasting is generally caused by protein-truncating mutations in the large DMD gene. Specific removal of an exon from a defective DMD gene transcript has the potential to allow synthesis of a semi-functional dystrophin, thereby reducing the severity and presumably progression of muscle wasting. The efficacy of this treatment will vary greatly between the different mutations that preclude the synthesis of a functional dystrophin. Restoration of the reading frame from a large multi-exon genomic deletion, typically greater than 36 exons, may lead to synthesis of a protein with only partial function and limited clinical benefit, whereas excising a nonsense mutation in a redundant exon should generate a near normal dystrophin. A clinical trial has recently confirmed proof-of-principle that exclusion of Exon 51 from human dystrophin mRNAs, carrying frame-shifting deletions adjacent to this exon, results in dystrophin expression. No major side-effects after local administration of the antisense oligomer were reported. Additional trials are underway, targeting the same exon but using an oligomer of different backbone chemistry. If functional dystrophin synthesis is demonstrated, and safety issues are addressed, subsequent trials will involve systemic delivery. Great challenges are ahead, some technical; establishing an effective delivery regimen, some ethical; choosing subsequent targets for therapy, and others of an administrative and regulatory nature.

  13. The evolutionary fate of alternatively spliced homologous exons after gene duplication.

    Science.gov (United States)

    Abascal, Federico; Tress, Michael L; Valencia, Alfonso

    2015-04-29

    Alternative splicing and gene duplication are the two main processes responsible for expanding protein functional diversity. Although gene duplication can generate new genes and alternative splicing can introduce variation through alternative gene products, the interplay between the two processes is complex and poorly understood. Here, we have carried out a study of the evolution of alternatively spliced exons after gene duplication to better understand the interaction between the two processes. We created a manually curated set of 97 human genes with mutually exclusively spliced homologous exons and analyzed the evolution of these exons across five distantly related vertebrates (lamprey, spotted gar, zebrafish, fugu, and coelacanth). Most of these exons had an ancient origin (more than 400 Ma). We found examples supporting two extreme evolutionary models for the behaviour of homologous axons after gene duplication. We observed 11 events in which gene duplication was accompanied by splice isoform separation, that is, each paralog specifically conserved just one distinct ancestral homologous exon. At other extreme, we identified genes in which the homologous exons were always conserved within paralogs, suggesting that the alternative splicing event cannot easily be separated from the function in these genes. That many homologous exons fall in between these two extremes highlights the diversity of biological systems and suggests that the subtle balance between alternative splicing and gene duplication is adjusted to the specific cellular context of each gene. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  14. Genome-wide survey of ds exonization to enrich transcriptomes and proteomes in plants.

    Science.gov (United States)

    Liu, Li-Yu Daisy; Charng, Yuh-Chyang

    2012-01-01

    Insertion of transposable elements (TEs) into introns can lead to their activation as alternatively spliced cassette exons, an event called exonization which can enrich the complexity of transcriptomes and proteomes. Previously, we performed the first experimental assessment of TE exonization by inserting a Ds element into each intron of the rice epsps gene. Exonization of Ds in plants was biased toward providing splice donor sites from the beginning of the inserted Ds sequence. Additionally, Ds inserted in the reverse direction resulted in a continuous splice donor consensus region by offering 4 donor sites in the same intron. The current study involved genome-wide computational analysis of Ds exonization events in the dicot Arabidopsis thaliana and the monocot Oryza sativa (rice). Up to 71% of the exonized transcripts were putative targets for the nonsense-mediated decay (NMD) pathway. The insertion patterns of Ds and the polymorphic splice donor sites increased the transcripts and subsequent protein isoforms. Protein isoforms contain protein sequence due to unspliced intron-TE region and/or a shift of the reading frame. The number of interior protein isoforms would be twice that of C-terminal isoforms, on average. TE exonization provides a promising way for functional expansion of the plant proteome.

  15. The first exon duplication mouse model of Duchenne muscular dystrophy: A tool for therapeutic development.

    Science.gov (United States)

    Vulin, Adeline; Wein, Nicolas; Simmons, Tabatha R; Rutherford, Andrea M; Findlay, Andrew R; Yurkoski, Jacqueline A; Kaminoh, Yuuki; Flanigan, Kevin M

    2015-11-01

    Exon duplication mutations account for up to 11% of all cases of Duchenne muscular dystrophy (DMD), and a duplication of exon 2 is the most common duplication in patients. For use as a platform for testing of duplication-specific therapies, we developed a mouse model that carries a Dmd exon 2 duplication. By using homologous recombination we duplicated exon 2 within intron 2 at a location consistent with a human duplication hotspot. mRNA analysis confirms the inclusion of a duplicated exon 2 in mouse muscle. Dystrophin expression is essentially absent by immunofluorescent and immunoblot analysis, although some muscle specimens show very low-level trace dystrophin expression. Phenotypically, the mouse shows similarities to mdx, the standard laboratory model of DMD. In skeletal muscle, areas of necrosis and phagocytosis are seen at 3 weeks, with central nucleation prominent by four weeks, recapitulating the "crisis" period in mdx. Marked diaphragm fibrosis is noted by 6 months, and remains unchanged at 12 months. Our results show that the Dup2 mouse is both pathologically (in degree and distribution) and physiologically similar to mdx. As it recapitulates the most common single exon duplication found in DMD patients, this new model will be a useful tool to assess the potential of duplicated exon skipping.

  16. Identification, characterization and expression of novel Sex Hormone Binding Globulin alternative first exons in the human prostate

    Directory of Open Access Journals (Sweden)

    de Torres Inés

    2009-06-01

    Full Text Available Abstract Background The human Sex Hormone Binding Globulin (SHBG gene, located at 17p13.1, comprises, at least, two different transcription units regulated by two different promoters. The first transcription unit begins with the exon 1 sequence and is responsible for the production of plasma SHBG by the hepatocytes, while the second begins with an alternative exon 1 sequence, which replaces the exon 1 present in liver transcripts. Alternative exon 1 transcription and translation has only been demonstrated in the testis of transgenic mice containing an 11-kb human SHBG transgene and in the human testis. Our goal has been to further characterize the 5' end of the SHBG gene and analyze the presence of the SHBG alternative transcripts in human prostate tissue and derived cell lines. Results Using a combination of in silico and in vitro studies, we have demonstrated that the SHBG gene, along with exon 1 and alternative exon 1 (renamed here exon 1A, contains four additional alternative first exons: the novel exons 1B, 1C, and 1E, and a previously identified exon 1N, which has been further characterized and renamed as exon 1D. We have shown that these four alternative first exons are all spliced to the same 3' splice site of SHBG exon 2, and that exon 1A and the novel exon 1B can be spliced to exon 1. We have also demonstrated the presence of SHBG transcripts beginning with exons 1B, 1C and 1D in prostate tissues and cell lines, as well as in several non-prostatic cell lines. Finally, the alignment of the SHBG mammalian sequences revealed that, while exons 1C, 1D and 1E are very well conserved phylogenetically through non-primate mammal species, exon 1B probably aroused in apes due to a single nucleotide change that generated a new 5' splice site in exon 1B. Conclusion The identification of multiple transcription start sites (TSS upstream of the annotated first exon of human SHBG, and the detection of the alternative transcripts in human prostate

  17. Functional analysis of splicing mutations in exon 7 of NF1 gene

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    Calvieri Stefano

    2007-02-01

    Full Text Available Abstract Background Neurofibromatosis type 1 is one of the most common autosomal dominant disorders, affecting about 1:3,500 individuals. NF1 exon 7 displays weakly defined exon-intron boundaries, and is particularly prone to missplicing. Methods In this study we investigated the expression of exon 7 transcripts using bioinformatic identification of splicing regulatory sequences, and functional minigene analysis of four sequence changes [c.910C>T (R304X, c.945G>A/c.946C>A (Q315Q/L316M, c.1005T>C (N335N] identified in exon 7 of three different NF1 patients. Results Our results detected the presence of three exonic splicing enhancers (ESEs and one putative exonic splicing silencer (ESS element. The wild type minigene assay resulted in three alternative isoforms, including a transcript lacking NF1 exon 7 (NF1ΔE7. Both the wild type and the mutated constructs shared NF1ΔE7 in addition to the complete messenger, but displayed a different ratio between the two transcripts. In the presence of R304X and Q315Q/L316M mutations, the relative proportion between the different isoforms is shifted toward the expression of NF1ΔE7, while in the presence of N335N variant, the NF1ΔE7 expression is abolished. Conclusion In conclusion, it appears mandatory to investigate the role of each nucleotide change within the NF1 coding sequence, since a significant proportion of NF1 exon 7 mutations affects pre-mRNA splicing, by disrupting exonic splicing motifs and modifying the delicate balance between aberrantly and correctly spliced transcripts.

  18. Tracking the evolution of alternatively spliced exons within the Dscam family

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    Vision Todd J

    2006-02-01

    Full Text Available Abstract Background The Dscam gene in the fruit fly, Drosophila melanogaster, contains twenty-four exons, four of which are composed of tandem arrays that each undergo mutually exclusive alternative splicing (4, 6, 9 and 17, potentially generating 38,016 protein isoforms. This degree of transcript diversity has not been found in mammalian homologs of Dscam. We examined the molecular evolution of exons within this gene family to locate the point of divergence for this alternative splicing pattern. Results Using the fruit fly Dscam exons 4, 6, 9 and 17 as seed sequences, we iteratively searched sixteen genomes for homologs, and then performed phylogenetic analyses of the resulting sequences to examine their evolutionary history. We found homologs in the nematode, arthropod and vertebrate genomes, including homologs in several vertebrates where Dscam had not been previously annotated. Among these, only the arthropods contain homologs arranged in tandem arrays indicative of mutually exclusive splicing. We found no homologs to these exons within the Arabidopsis, yeast, tunicate or sea urchin genomes but homologs to several constitutive exons from fly Dscam were present within tunicate and sea urchin. Comparing the rate of turnover within the tandem arrays of the insect taxa (fruit fly, mosquito and honeybee, we found the variants within exons 4 and 17 are well conserved in number and spatial arrangement despite 248–283 million years of divergence. In contrast, the variants within exons 6 and 9 have undergone considerable turnover since these taxa diverged, as indicated by deeply branching taxon-specific lineages. Conclusion Our results suggest that at least one Dscam exon array may be an ancient duplication that predates the divergence of deuterostomes from protostomes but that there is no evidence for the presence of arrays in the common ancestor of vertebrates. The different patterns of conservation and turnover among the Dscam exon arrays

  19. Changes in exon–intron structure during vertebrate evolution affect the splicing pattern of exons

    Science.gov (United States)

    Gelfman, Sahar; Burstein, David; Penn, Osnat; Savchenko, Anna; Amit, Maayan; Schwartz, Schraga; Pupko, Tal; Ast, Gil

    2012-01-01

    Exon–intron architecture is one of the major features directing the splicing machinery to the short exons that are located within long flanking introns. However, the evolutionary dynamics of exon–intron architecture and its impact on splicing is largely unknown. Using a comparative genomic approach, we analyzed 17 vertebrate genomes and reconstructed the ancestral motifs of both 3′ and 5′ splice sites, as also the ancestral length of exons and introns. Our analyses suggest that vertebrate introns increased in length from the shortest ancestral introns to the longest primate introns. An evolutionary analysis of splice sites revealed that weak splice sites act as a restrictive force keeping introns short. In contrast, strong splice sites allow recognition of exons flanked by long introns. Reconstruction of the ancestral state suggests these phenomena were not prevalent in the vertebrate ancestor, but appeared during vertebrate evolution. By calculating evolutionary rate shifts in exons, we identified cis-acting regulatory sequences that became fixed during the transition from early vertebrates to mammals. Experimental validations performed on a selection of these hexamers confirmed their regulatory function. We additionally revealed many features of exons that can discriminate alternative from constitutive exons. These features were integrated into a machine-learning approach to predict whether an exon is alternative. Our algorithm obtains very high predictive power (AUC of 0.91), and using these predictions we have identified and successfully validated novel alternatively spliced exons. Overall, we provide novel insights regarding the evolutionary constraints acting upon exons and their recognition by the splicing machinery. PMID:21974994

  20. Molecular analysis of contiguous exons of the phenylalanine hydroxylase gene: identification of a new PKU mutation.

    OpenAIRE

    Dianzani, I; Camaschella, C.; Saglio, G; Ferrero, G B; Ramus, S; Ponzone, A; Cotton, R G

    1993-01-01

    A modified application of the chemical cleavage of mismatch (CCM) method has been used to screen three contiguous exons (exons 9, 10, and 11) of the phenylalanine hydroxylase gene in 17 Italian PKU patients. A new nonsense heterozygous C-->G transversion within exon 11 (S359X) was identified in a single patient. Only one of the four mutations previously reported in this DNA region in Caucasians was found. This lesion, IVS X-546, was detected in five of the 34 PKU alleles examined. Our results...

  1. Gastrointestinal malignancies harbor actionable MET exon 14 deletions

    Science.gov (United States)

    Hong, Mineui; Kim, Sun Young; Jang, Jiryeon; Ahn, Soomin; Kang, So Young; Lee, Sujin; Kim, Seung Tae; Kim, Bogyou; Choi, Jaehyun; Kim, Kyung-Ah; Lee, Jiyun; Park, Charny; Park, Se Hoon; Park, Joon Oh; Lim, Ho Yeong; Kang, Won Ki; Park, Keunchil; Park, Young Suk; Kim, Kyoung-Mee

    2015-01-01

    Recently, MET exon 14 deletion (METex14del) has been postulated to be one potential mechanism for MET protein overexpression. We screened for the presence of METex14del transcript by multiplexed fusion transcript analysis using nCounter assay followed by confirmation with quantitative reverse transcription PCR with correlation to MET protein expression by immunohistochemistry (IHC) and MET amplification by fluorescence in situ hybridization (FISH). We extracted RNAs from 230 patients enrolled onto the prospective molecular profiling clinical trial (NEXT-1) (NCT02141152) between November 2013 and August 2014. Thirteen METex14del cases were identified including 3 gastric cancer, 4 colon cancer, 5 non-small cell lung cancer, and one adenocarcinoma of unknown primary. Of these 13 METex14del cases, 11 were MET IHC 3+ and 2 were 2+. Only one out of the 13 METex14del cases was MET amplified (MET/CEP ratio > 2.0). Growths of two (gastric, colon) METex14del+ patient tumor derived cell lines were profoundly inhibited by both MET tyrosine kinase inhibitors and a monoclonal antibody targeting MET. In conclusion, METex14del is a unique molecular aberration present in gastrointestinal (GI) malignancies corresponding with overexpression of MET protein but rarely with MET amplification. Substantial growth inhibition of METex14del+ patient tumor derived cell lines by several MET targeting drugs strongly suggests METex14del is a potential actionable driver mutation in GI malignancies. PMID:26375439

  2. Variants Within TSC2 Exons 25 and 31 Are Very Unlikely to Cause Clinically Diagnosable Tuberous Sclerosis.

    Science.gov (United States)

    Ekong, Rosemary; Nellist, Mark; Hoogeveen-Westerveld, Marianne; Wentink, Marjolein; Panzer, Jessica; Sparagana, Steven; Emmett, Warren; Dawson, Natalie L; Malinge, Marie Claire; Nabbout, Rima; Carbonara, Caterina; Barberis, Marco; Padovan, Sergio; Futema, Marta; Plagnol, Vincent; Humphries, Steve E; Migone, Nicola; Povey, Sue

    2016-04-01

    Inactivating mutations in TSC1 and TSC2 cause tuberous sclerosis complex (TSC). The 2012 international consensus meeting on TSC diagnosis and management agreed that the identification of a pathogenic TSC1 or TSC2 variant establishes a diagnosis of TSC, even in the absence of clinical signs. However, exons 25 and 31 of TSC2 are subject to alternative splicing. No variants causing clinically diagnosed TSC have been reported in these exons, raising the possibility that such variants would not cause TSC. We present truncating and in-frame variants in exons 25 and 31 in three individuals unlikely to fulfil TSC diagnostic criteria and examine the importance of these exons in TSC using different approaches. Amino acid conservation analysis suggests significantly less conservation in these exons compared with the majority of TSC2 exons, and TSC2 expression data demonstrates that the majority of TSC2 transcripts lack exons 25 and/or 31 in many human adult tissues. In vitro assay of both exons shows that neither exon is essential for TSC complex function. Our evidence suggests that variants in TSC2 exons 25 or 31 are very unlikely to cause classical TSC, although a role for these exons in tissue/stage specific development cannot be excluded.

  3. Analysis of KIT expression and KIT exon 11 mutations in canine oral malignant melanomas.

    Science.gov (United States)

    Murakami, A; Mori, T; Sakai, H; Murakami, M; Yanai, T; Hoshino, Y; Maruo, K

    2011-09-01

    KIT, a transmembrane receptor tyrosine kinase, is one of the specific targets for anti-cancer therapy. In humans, its expression and mutations have been identified in malignant melanomas and therapies using molecular-targeted agents have been promising in these tumours. As human malignant melanoma, canine malignant melanoma is a fatal disease with metastases and the poor response has been observed with all standard protocols. In our study, KIT expression and exon 11 mutations in dogs with histologically confirmed malignant oral melanomas were evaluated. Although 20 of 39 cases were positive for KIT protein, there was no significant difference between KIT expression and overall survival. Moreover, polymerase chain reaction amplification and sequencing of KIT exon 11 in 17 samples did not detect any mutations and proved disappointing. For several reasons, however, KIT expression and mutations of various exons including exon 11 should be investigated in more cases.

  4. Functional evaluation of targeted exon deletion reveals prospect for dystrophic epidermolysis bullosa therapy

    NARCIS (Netherlands)

    Bornert, Olivier; Kühl, Tobias; Bremer, Jeroen; Van Den Akker, Peter C; Pasmooij, Anna M G; Nyström, Alexander

    2016-01-01

    Genetically evoked deficiency of collagen VII causes dystrophic epidermolysis bullosa (DEB) - a debilitating disease characterized by chronic skin fragility and progressive fibrosis. Removal of exons carrying frame-disrupting mutations can reinstate protein expression in genetic diseases. The therap

  5. Decoding of exon splicing patterns in the human RUNX1-RUNX1T1 fusion gene.

    Science.gov (United States)

    Grinev, Vasily V; Migas, Alexandr A; Kirsanava, Aksana D; Mishkova, Olga A; Siomava, Natalia; Ramanouskaya, Tatiana V; Vaitsiankova, Alina V; Ilyushonak, Ilia M; Nazarov, Petr V; Vallar, Laurent; Aleinikova, Olga V

    2015-11-01

    The t(8;21) translocation is the most widespread genetic defect found in human acute myeloid leukemia. This translocation results in the RUNX1-RUNX1T1 fusion gene that produces a wide variety of alternative transcripts and influences the course of the disease. The rules of combinatorics and splicing of exons in the RUNX1-RUNX1T1 transcripts are not known. To address this issue, we developed an exon graph model of the fusion gene organization and evaluated its local exon combinatorics by the exon combinatorial index (ECI). Here we show that the local exon combinatorics of the RUNX1-RUNX1T1 gene follows a power-law behavior and (i) the vast majority of exons has a low ECI, (ii) only a small part is represented by "exons-hubs" of splicing with very high ECI values, and (iii) it is scale-free and very sensitive to targeted skipping of "exons-hubs". Stochasticity of the splicing machinery and preferred usage of exons in alternative splicing can explain such behavior of the system. Stochasticity may explain up to 12% of the ECI variance and results in a number of non-coding and unproductive transcripts that can be considered as a noise. Half-life of these transcripts is increased due to the deregulation of some key genes of the nonsense-mediated decay system in leukemia cells. On the other hand, preferred usage of exons may explain up to 75% of the ECI variability. Our analysis revealed a set of splicing-related cis-regulatory motifs that can explain "attractiveness" of exons in alternative splicing but only when they are considered together. Cis-regulatory motifs are guides for splicing trans-factors and we observed a leukemia-specific profile of expression of the splicing genes in t(8;21)-positive blasts. Altogether, our results show that alternative splicing of the RUNX1-RUNX1T1 transcripts follows strict rules and that the power-law component of the fusion gene organization confers a high flexibility to this process.

  6. Plant Proteins Are Smaller Because They Are Encoded by Fewer Exons than Animal Proteins

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    Obed Ramírez-Sánchez

    2016-12-01

    Full Text Available Protein size is an important biochemical feature since longer proteins can harbor more domains and therefore can display more biological functionalities than shorter proteins. We found remarkable differences in protein length, exon structure, and domain count among different phylogenetic lineages. While eukaryotic proteins have an average size of 472 amino acid residues (aa, average protein sizes in plant genomes are smaller than those of animals and fungi. Proteins unique to plants are ∼81 aa shorter than plant proteins conserved among other eukaryotic lineages. The smaller average size of plant proteins could neither be explained by endosymbiosis nor subcellular compartmentation nor exon size, but rather due to exon number. Metazoan proteins are encoded on average by ∼10 exons of small size [∼176 nucleotides (nt]. Streptophyta have on average only ∼5.7 exons of medium size (∼230 nt. Multicellular species code for large proteins by increasing the exon number, while most unicellular organisms employ rather larger exons (>400 nt. Among subcellular compartments, membrane proteins are the largest (∼520 aa, whereas the smallest proteins correspond to the gene ontology group of ribosome (∼240 aa. Plant genes are encoded by half the number of exons and also contain fewer domains than animal proteins on average. Interestingly, endosymbiotic proteins that migrated to the plant nucleus became larger than their cyanobacterial orthologs. We thus conclude that plants have proteins larger than bacteria but smaller than animals or fungi. Compared to the average of eukaryotic species, plants have ∼34% more but ∼20% smaller proteins. This suggests that photosynthetic organisms are unique and deserve therefore special attention with regard to the evolutionary forces acting on their genomes and proteomes.

  7. Intersubtype Genetic Variation of HIV-1 Tat Exon 1.

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    Roy, Chandra Nath; Khandaker, Irona; Oshitani, Hitoshi

    2015-06-01

    HIV-1 Tat is a regulatory protein that plays a pivotal role in viral transcription and replication. Our study aims to investigate the genetic variation of Tat exon 1 in all subtypes of HIV-1: A, B, C, D, F, G, H, J, and K. We performed phylogenetic, mutation, and selection pressure analyses on a total of 1,179 sequences of different subtypes of HIV-1 Tat obtained from the Los Alamos National Laboratory (LANL). The mean nucleotide divergences (%) among the analyzed sequences of subtypes A, B, C, D, F, G, H, J, and K were 88, 89, 90, 88, 86, 89, 88, 97, and 97, respectively. We revealed that subtype B evolved relatively faster than other subtypes. The second and fifth domains were found comparatively more variable among all subtypes. Site-by-site tests of positive selection revealed that several positions in all subtypes were under significant positive selection. Positively selected sites were found in the acidic domain at positions 3, 4, and 19, in the cysteine-rich domains at positions 24, 29, 32, and 36, in the core domain at position 40, and in the basic domain for the rest of the positions for all subtypes. Positions 58 and 68 in the basic domain were positively selected in subtypes A, B, C and B, C, F, respectively. We also observed high variability within positively selected sites in amino acid positions. Our study findings on HIV-1 Tat genetic variability may contribute to a better understanding of HIV-1 evolution as well as to the development of effective Tat-targeted therapeutics and vaccines.

  8. Molecular characterization of exon 3 of caprine myostatin gene in Marwari goat

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    Jai Prakash Khichar

    2016-06-01

    Full Text Available Aim: To estimate genetic variability in exon 3 of caprine myostatin gene in Marwari goats. Materials and Methods: A total of 120 blood samples from unrelated Marwari goats were randomly collected from different villages of Bikaner (Rajasthan, India. Genomic DNA was extracted from whole blood using blood DNA isolation kit (Himedia Ltd. as per manufacturer’s protocol. The quality of extracted genomic DNA was checked on 0.8% agarose gel. Specifically designed a primer set for caprine myostatin (MSTN gene (Genebank accession no. DQ167575 was used to amplify the exon 3 region of MSTN gene in Marwari goat. The genetic variability in exon 3 of MSTN gene in Marwari goat was assessed on 8% polyacrylamide gel electrophoresis to detect single strand conformation polymorphism (SSCP pattern. Results: The exon 3 of MSTN gene in Marwari goat showed two types of conformation patterns on 8% polyacrylamide gel. One of the patterns showed only two bands and was considered as genotype AA, whereas another pattern having an extra band was designated as genotype AB. The frequencies of AA and AB genotype for exon 3 region of MSTN gene were calculated as 0.90 and 0.10, respectively. Conclusion: Low level of polymorphism was observed at exon 3 region of MSTN gene in Marwari goat through SSCP analysis. This information could be utilized in future breeding plan to exploit the unique characteristics of Marwari goat of Rajasthan.

  9. Compensatory relationship between splice sites and exonic splicing signals depending on the length of vertebrate introns

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    Rogozin Igor B

    2006-12-01

    Full Text Available Abstract Background The signals that determine the specificity and efficiency of splicing are multiple and complex, and are not fully understood. Among other factors, the relative contributions of different mechanisms appear to depend on intron size inasmuch as long introns might hinder the activity of the spliceosome through interference with the proper positioning of the intron-exon junctions. Indeed, it has been shown that the information content of splice sites positively correlates with intron length in the nematode, Drosophila, and fungi. We explored the connections between the length of vertebrate introns, the strength of splice sites, exonic splicing signals, and evolution of flanking exons. Results A compensatory relationship is shown to exist between different types of signals, namely, the splice sites and the exonic splicing enhancers (ESEs. In the range of relatively short introns (approximately, Conclusion Several weak but statistically significant correlations were observed between vertebrate intron length, splice site strength, and potential exonic splicing signals. Taken together, these findings attest to a compensatory relationship between splice sites and exonic splicing signals, depending on intron length.

  10. Menzerath-Altmann law in mammalian exons reflects the dynamics of gene structure evolution.

    Science.gov (United States)

    Nikolaou, Christoforos

    2014-12-01

    Genomic sequences exhibit self-organization properties at various hierarchical levels. One such is the gene structure of higher eukaryotes with its complex exon/intron arrangement. Exon sizes and exon numbers in genes have been shown to conform to a law derived from statistical linguistics and formulated by Menzerath and Altmann, according to which the mean size of the constituents of an entity is inversely related to the number of these constituents. We herein perform a detailed analysis of this property in the complete exon set of the mouse genome in correlation to the sequence conservation of each exon and the transcriptional complexity of each gene locus. We show that extensive linear fits, representative of accordance to Menzerath-Altmann law are restricted to a particular subset of genes that are formed by exons under low or intermediate sequence constraints and have a small number of alternative transcripts. Based on this observation we propose a hypothesis for the law of Menzerath-Altmann in mammalian genes being predominantly due to genes that are more versatile in function and thus, more prone to undergo changes in their structure. To this end we demonstrate one test case where gene categories of different functionality also show differences in the extent of conformity to Menzerath-Altmann law. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Endogenous Multiple Exon Skipping and Back-Splicing at the DMD Mutation Hotspot

    Science.gov (United States)

    Suzuki, Hitoshi; Aoki, Yoshitsugu; Kameyama, Toshiki; Saito, Takashi; Masuda, Satoru; Tanihata, Jun; Nagata, Tetsuya; Mayeda, Akila; Takeda, Shin’ichi; Tsukahara, Toshifumi

    2016-01-01

    Duchenne muscular dystrophy (DMD) is a severe muscular disorder. It was reported that multiple exon skipping (MES), targeting exon 45–55 of the DMD gene, might improve patients’ symptoms because patients who have a genomic deletion of all these exons showed very mild symptoms. Thus, exon 45–55 skipping treatments for DMD have been proposed as a potential clinical cure. Herein, we detected the expression of endogenous exons 44–56 connected mRNA transcript of the DMD using total RNAs derived from human normal skeletal muscle by reverse transcription polymerase chain reaction (RT-PCR), and identified a total of eight types of MES products around the hotspot. Surprisingly, the 5′ splice sites of recently reported post-transcriptional introns (remaining introns after co-transcriptional splicing) act as splicing donor sites for MESs. We also tested exon combinations to generate DMD circular RNAs (circRNAs) and determined the preferential splice sites of back-splicing, which are involved not only in circRNA generation, but also in MESs. Our results fit the current circRNA-generation model, suggesting that upstream post-transcriptional introns trigger MES and generate circRNA because its existence is critical for the intra-intronic interaction or for extremely distal splicing. PMID:27754374

  12. Alternative splicing of anciently exonized 5S rRNA regulates plant transcription factor TFIIIA.

    Science.gov (United States)

    Fu, Yan; Bannach, Oliver; Chen, Hao; Teune, Jan-Hendrik; Schmitz, Axel; Steger, Gerhard; Xiong, Liming; Barbazuk, W Brad

    2009-05-01

    Identifying conserved alternative splicing (AS) events among evolutionarily distant species can prioritize AS events for functional characterization and help uncover relevant cis- and trans-regulatory factors. A genome-wide search for conserved cassette exon AS events in higher plants revealed the exonization of 5S ribosomal RNA (5S rRNA) within the gene of its own transcription regulator, TFIIIA (transcription factor for polymerase III A). The 5S rRNA-derived exon in TFIIIA gene exists in all representative land plant species but not in green algae and nonplant species, suggesting it is specific to land plants. TFIIIA is essential for RNA polymerase III-based transcription of 5S rRNA in eukaryotes. Integrating comparative genomics and molecular biology revealed that the conserved cassette exon derived from 5S rRNA is coupled with nonsense-mediated mRNA decay. Utilizing multiple independent Arabidopsis overexpressing TFIIIA transgenic lines under osmotic and salt stress, strong accordance between phenotypic and molecular evidence reveals the biological relevance of AS of the exonized 5S rRNA in quantitative autoregulation of TFIIIA homeostasis. Most significantly, this study provides the first evidence of ancient exaptation of 5S rRNA in plants, suggesting a novel gene regulation model mediated by the AS of an anciently exonized noncoding element.

  13. Crystal Structure of the CLOCK Transactivation Domain Exon19 in Complex with a Repressor

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    Hou, Zhiqiang; Su, Lijing; Pei, Jimin; Grishin, Nick V.; Zhang, Hong

    2017-08-01

    In the canonical clock model, CLOCK:BMAL1-mediated transcriptional activation is feedback regulated by its repressors CRY and PER and, in association with other coregulators, ultimately generates oscillatory gene expression patterns. How CLOCK:BMAL1 interacts with coregulator(s) is not well understood. Here we report the crystal structures of the mouse CLOCK transactivating domain Exon19 in complex with CIPC, a potent circadian repressor that functions independently of CRY and PER. The Exon19:CIPC complex adopts a three-helical coiled-coil bundle conformation containing two Exon19 helices and one CIPC. Unique to Exon19:CIPC, three highly conserved polar residues, Asn341 of CIPC and Gln544 of the two Exon19 helices, are located at the mid-section of the coiled-coil bundle interior and form hydrogen bonds with each other. Combining results from protein database search, sequence analysis, and mutagenesis studies, we discovered for the first time that CLOCK Exon19:CIPC interaction is a conserved transcription regulatory mechanism among mammals, fish, flies, and other invertebrates.

  14. NF1 single and multi-exons copy number variations in neurofibromatosis type 1.

    Science.gov (United States)

    Imbard, Apolline; Pasmant, Eric; Sabbagh, Audrey; Luscan, Armelle; Soares, Magali; Goussard, Philippe; Blanché, Hélène; Laurendeau, Ingrid; Ferkal, Salah; Vidaud, Michel; Pinson, Stéphane; Bellanne-Chantelot, Christine; Vidaud, Dominique; Wolkenstein, Pierre; Parfait, Béatrice

    2015-04-01

    Neurofibromatosis type 1 (NF1) is caused by dominant loss-of-function mutations of the tumor suppressor NF1 containing 57 constitutive coding exons. A huge number of different pathogenic NF1 alterations has been reported. The aim of the present study was to evaluate the usefulness of a multiplex ligation-dependent probe amplification (MLPA) approach in NF1 patients to detect single and multi-exon NF1 gene copy number variations. A genotype-phenotype correlation was then performed in NF1 patients carrying these types of genetic alterations. Among 565 NF1 index cases from the French NF1 cohort, single and multi-exon deletions/duplications screening identified NF1 partial deletions/duplications in 22 patients (~4%) using MLPA analysis. Eight single exon deletions, 11 multiple exons deletions, 1 complex rearrangement and 2 duplications were identified. All results were confirmed using a custom array-CGH. MLPA and custom array-CGH allowed the identification of rearrangements that were missed by cDNA/DNA sequencing or microsatellite analysis. We then performed a targeted next-generation sequencing of NF1 that allowed confirmation of all 22 rearrangements. No clear genotype-phenotype correlations were found for the most clinically significant disease features of NF1 in patients with single and multi-exons NF1 gene copy number changes.

  15. Systematic dissection of coding exons at single nucleotide resolution supports an additional role in cell-specific transcriptional regulation.

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    Ramon Y Birnbaum

    2014-10-01

    Full Text Available In addition to their protein coding function, exons can also serve as transcriptional enhancers. Mutations in these exonic-enhancers (eExons could alter both protein function and transcription. However, the functional consequence of eExon mutations is not well known. Here, using massively parallel reporter assays, we dissect the enhancer activity of three liver eExons (SORL1 exon 17, TRAF3IP2 exon 2, PPARG exon 6 at single nucleotide resolution in the mouse liver. We find that both synonymous and non-synonymous mutations have similar effects on enhancer activity and many of the deleterious mutation clusters overlap known liver-associated transcription factor binding sites. Carrying a similar massively parallel reporter assay in HeLa cells with these three eExons found differences in their mutation profiles compared to the liver, suggesting that enhancers could have distinct operating profiles in different tissues. Our results demonstrate that eExon mutations could lead to multiple phenotypes by disrupting both the protein sequence and enhancer activity and that enhancers can have distinct mutation profiles in different cell types.

  16. Development of Therapeutic Chimeric Uricase by Exon Replacement/Restoration and Site-Directed Mutagenesis

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    Guangrong Xie

    2016-05-01

    Full Text Available The activity of urate oxidase was lost during hominoid evolution, resulting in high susceptibility to hyperuricemia and gout in humans. In order to develop a more “human-like” uricase for therapeutic use, exon replacement/restoration and site-directed mutagenesis were performed to obtain porcine–human uricase with higher homology to deduced human uricase (dHU and increased uricolytic activity. In an exon replacement study, substitution of exon 6 in wild porcine uricase (wPU gene with corresponding exon in dhu totally abolished its activity. Substitutions of exon 5, 3, and 1–2 led to 85%, 60%, and 45% loss of activity, respectively. However, replacement of exon 4 and 7–8 did not significantly change the enzyme activity. When exon 5, 6, and 3 in dhu were replaced by their counterparts in wpu, the resulting chimera H1-2P3H4P5-6H7-8 was active, but only about 28% of wPU. Multiple sequence alignment and homology modeling predicted that mutations of E24D and E83G in H1-2P3H4P5-6H7-8 were favorable for further increase of its activity. After site-directed mutagenesis, H1-2P3H4P5-6H7-8 (E24D & E83G with increased homology (91.45% with dHU and higher activity and catalytic efficiency than the FDA-approved porcine–baboon chimera (PBC was obtained. It showed optimum activity at pH 8.5 and 35 °C and was stable in a pH range of 6.5–11.0 and temperature range of 20–40 °C.

  17. A Brassica exon array for whole-transcript gene expression profiling.

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    Christopher G Love

    Full Text Available Affymetrix GeneChip® arrays are used widely to study transcriptional changes in response to developmental and environmental stimuli. GeneChip® arrays comprise multiple 25-mer oligonucleotide probes per gene and retain certain advantages over direct sequencing. For plants, there are several public GeneChip® arrays whose probes are localised primarily in 3' exons. Plant whole-transcript (WT GeneChip® arrays are not yet publicly available, although WT resolution is needed to study complex crop genomes such as Brassica, which are typified by segmental duplications containing paralogous genes and/or allopolyploidy. Available sequence data were sampled from the Brassica A and C genomes, and 142,997 gene models identified. The assembled gene models were then used to establish a comprehensive public WT exon array for transcriptomics studies. The Affymetrix GeneChip® Brassica Exon 1.0 ST Array is a 5 µM feature size array, containing 2.4 million 25-base oligonucleotide probes representing 135,201 gene models, with 15 probes per gene distributed among exons. Discrimination of the gene models was based on an E-value cut-off of 1E(-5, with ≤98% sequence identity. The 135 k Brassica Exon Array was validated by quantifying transcriptome differences between leaf and root tissue from a reference Brassica rapa line (R-o-18, and categorisation by Gene Ontologies (GO based on gene orthology with Arabidopsis thaliana. Technical validation involved comparison of the exon array with a 60-mer array platform using the same starting RNA samples. The 135 k Brassica Exon Array is a robust platform. All data relating to the array design and probe identities are available in the public domain and are curated within the BrassEnsembl genome viewer at http://www.brassica.info/BrassEnsembl/index.html.

  18. Therapeutic NOTCH3 cysteine correction in CADASIL using exon skipping: in vitro proof of concept.

    Science.gov (United States)

    Rutten, Julie W; Dauwerse, Hans G; Peters, Dorien J M; Goldfarb, Andrew; Venselaar, Hanka; Haffner, Christof; van Ommen, Gert-Jan B; Aartsma-Rus, Annemieke M; Lesnik Oberstein, Saskia A J

    2016-04-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, or CADASIL, is a hereditary cerebral small vessel disease caused by characteristic cysteine altering missense mutations in the NOTCH3 gene. NOTCH3 mutations in CADASIL result in an uneven number of cysteine residues in one of the 34 epidermal growth factor like-repeat (EGFr) domains of the NOTCH3 protein. The consequence of an unpaired cysteine residue in an EGFr domain is an increased multimerization tendency of mutant NOTCH3, leading to toxic accumulation of the protein in the (cerebro)vasculature, and ultimately reduced cerebral blood flow, recurrent stroke and vascular dementia. There is no therapy to delay or alleviate symptoms in CADASIL. We hypothesized that exclusion of the mutant EGFr domain from NOTCH3 would abolish the detrimental effect of the unpaired cysteine and thus prevent toxic NOTCH3 accumulation and the negative cascade of events leading to CADASIL. To accomplish this NOTCH3 cysteine correction by EGFr domain exclusion, we used pre-mRNA antisense-mediated skipping of specific NOTCH3 exons. Selection of these exons was achieved using in silico studies and based on the criterion that skipping of a particular exon or exon pair would modulate the protein in such a way that the mutant EGFr domain is eliminated, without otherwise corrupting NOTCH3 structure and function. Remarkably, we found that this strategy closely mimics evolutionary events, where the elimination and fusion of NOTCH EGFr domains led to the generation of four functional NOTCH homologues. We modelled a selection of exon skip strategies using cDNA constructs and show that the skip proteins retain normal protein processing, can bind ligand and be activated by ligand. We then determined the technical feasibility of targeted NOTCH3 exon skipping, by designing antisense oligonucleotides targeting exons 2-3, 4-5 and 6, which together harbour the majority of distinct CADASIL-causing mutations

  19. Mutations of p53 gene exons 4-8 in human esophageal cancer

    Institute of Scientific and Technical Information of China (English)

    Li-Ya Li; Jin-Tian Tang; Li-Qun Jia; Pei-Wen Li

    2005-01-01

    AIM: To characterize the tumor suppressor gene p53 mutations in exon 4, esophageal cancer and adjacent noncancerous tissues.METHODS: We performed p53 (exons 4-8) gene mutation analysis on 24 surgically resected human esophageal cancer specimens by PCR, single-strand conformation polymorphism, and DNA sequencing. RESULTS: p53 gene mutations were detected in 9 of 22 (40.9%) esophageal cancer specimens and 10 of 17 (58.8%) adjacent non-cancerous tissues. Eight of sixteen (50.0%) point mutations detected were G-A transitions and 9 of 18 (50.0%) p53 gene mutations occurred in exon 4 in esophageal cancer specimens. Only 1 of 11 mutations detected was G-A transition and 4 of 11 (36.4%) p53 gene mutations occurred in exon 4 in adjacent non-cancerous tissues.CONCLUSION: Mutation of p53 gene in exon 4 may play an important role in development of esophageal cancer. The observation of p53 gene mutation in adjacent noncancerous tissues suggests that p53 gene mutation may be an early event in esophageal carcinogenesis. Some clinical factors, including age, sex, pre-operation therapy and location of tumors, do not influence p53 gene mutation rates.

  20. Molecular Diagnosis of Duchenne/Becker Muscular Dystrophy: Analysis of Exons Deletion and Carrier Detection

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    Mohammad Taghi Akbari

    2010-01-01

    Full Text Available Objective: Duchenne and Becker Muscular Dystrophy (DMD and BMD are X-linked conditionsresulting from a defect in the dystrophin gene located at Xp21.2. DMD is the mostfrequent neuromuscular disease in humans (1/3500 male newborns. In approximately65% of DMD and BMD patients, deletions in the dystrophin gene have been identified asthe molecular determinant. The frequency and distribution of dystrophin gene deletions inDMD/BMD patients from different populations are different.The aim of this study was to delineate various types of deleted exons and their frequencyin affected male patients and identification of carrier females by linkage analysis.Materials and Methods: In this study 100 unrelated patients with DMD/BMD were studiedfor intragenic deletions in 28 exons and the promoter region of the dystrophin geneusing multiplex PCR. We also performed linkage analysis within the dystrophin gene utilizing8 short tandem repeat markers.Results: Fifty-two (52% patients showed intragenic deletions. A total of 81% of the deletionswere located at the distal hot spot region (44-55 exons and 19% of the deletionswere located at the proximal region (exon 2-19. The most frequent deleted exons were47(16%, 48 and 46 (11%.Most of the STR markers showed heterozygosity in the families studied. The linkageanalysis was useful for detecting carrier status.Conclusion: The present study suggests that intragenic dystrophin gene deletions occurwith the same frequency in Iranian patients compared with other ethnic groups.

  1. Differential splicing of exon 5 of the Wilms tumour (WTI) gene.

    Science.gov (United States)

    Renshaw, J; King-Underwood, L; Pritchard-Jones, K

    1997-08-01

    The WTI gene encodes a developmentally regulated transcription factor whose function is altered by alternative splicing at two sites: the 17 amino acids of exon 5, whose functional effects are ill-defined, and the 3 amino acids (KTS) between exons 9 and 10, which determine sequence-specific DNA binding and nuclear localisation. Germline mutations, which prevent normal KTS splicing, can underlie the Denys-Drash syndrome, and disruptions of splicing of exon 5 may occur in Wilms tumours. We analysed by reverse transcriptase polymerase chain reaction (RT-PCR) amplification the relative ratios of the four splice variants of WTI mRNA in normal and tumour tissues and found tissue-specific, developmental stage-specific, and species-specific differences in the splicing of exon 5 but not of KTS. We found no evidence for disrupted splicing in acute leukaemias or gonadal tumours. The significance of these findings is discussed, and the possibility is raised that WTI may orchestrate the appropriate response to growth and differentiation factor signalling, mediated by alterations in the relative levels of exon 5 containing WTI isoforms.

  2. Huntingtin exon 1 fibrils feature an interdigitated β-hairpin-based polyglutamine core.

    Science.gov (United States)

    Hoop, Cody L; Lin, Hsiang-Kai; Kar, Karunakar; Magyarfalvi, Gábor; Lamley, Jonathan M; Boatz, Jennifer C; Mandal, Abhishek; Lewandowski, Józef R; Wetzel, Ronald; van der Wel, Patrick C A

    2016-02-09

    Polyglutamine expansion within the exon1 of huntingtin leads to protein misfolding, aggregation, and cytotoxicity in Huntington's disease. This incurable neurodegenerative disease is the most prevalent member of a family of CAG repeat expansion disorders. Although mature exon1 fibrils are viable candidates for the toxic species, their molecular structure and how they form have remained poorly understood. Using advanced magic angle spinning solid-state NMR, we directly probe the structure of the rigid core that is at the heart of huntingtin exon1 fibrils and other polyglutamine aggregates, via measurements of long-range intramolecular and intermolecular contacts, backbone and side-chain torsion angles, relaxation measurements, and calculations of chemical shifts. These experiments reveal the presence of β-hairpin-containing β-sheets that are connected through interdigitating extended side chains. Despite dramatic differences in aggregation behavior, huntingtin exon1 fibrils and other polyglutamine-based aggregates contain identical β-strand-based cores. Prior structural models, derived from X-ray fiber diffraction and computational analyses, are shown to be inconsistent with the solid-state NMR results. Internally, the polyglutamine amyloid fibrils are coassembled from differently structured monomers, which we describe as a type of "intrinsic" polymorphism. A stochastic polyglutamine-specific aggregation mechanism is introduced to explain this phenomenon. We show that the aggregation of mutant huntingtin exon1 proceeds via an intramolecular collapse of the expanded polyglutamine domain and discuss the implications of this observation for our understanding of its misfolding and aggregation mechanisms.

  3. Intrasplicing coordinates alternative first exons with alternative splicing in the protein 4.1R gene

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    Conboy, John G.; Parra, Marilyn K.; Tan, Jeff S.; Mohandas, Narla; Conboy, John G.

    2008-11-07

    In the protein 4.1R gene, alternative first exons splice differentially to alternative 3' splice sites far downstream in exon 2'/2 (E2'/2). We describe a novel intrasplicing mechanism by which exon 1A (E1A) splices exclusively to the distal E2'/2 acceptor via two nested splicing reactions regulated by novel properties of exon 1B (E1B). E1B behaves as an exon in the first step, using its consensus 5' donor to splice to the proximal E2'/2 acceptor. A long region of downstream intron is excised, juxtaposing E1B with E2'/2 to generate a new composite acceptor containing the E1B branchpoint/pyrimidine tract and E2 distal 3' AG-dinucleotide. Next, the upstream E1A splices over E1B to this distal acceptor, excising the remaining intron plus E1B and E2' to form mature E1A/E2 product. We mapped branch points for both intrasplicing reactions and demonstrated that mutation of the E1B 5' splice site or branchpoint abrogates intrasplicing. In the 4.1R gene, intrasplicing ultimately determines N-terminal protein structure and function. More generally, intrasplicing represents a new mechanism whereby alternative promoters can be coordinated with downstream alternative splicing.

  4. KIT exon 11 deletion-inversions represent complex mutations in gastrointestinal stromal tumors.

    Science.gov (United States)

    Lasota, Jerzy; Miettinen, Markku

    2007-05-01

    Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. KIT expression and mutational KIT activation have been documented in a majority of GISTs. Most mutations have been found in KIT juxtamembrane domain encoded by exon 11. Recently, we have identified three, complex KIT exon 11 mutations previously unreported in GISTs. These mutations consisted of several nucleotide deletions accompanied by insertions of inverted complementary DNA strand sequences. All three mutations were found in the 5' part of KIT exon 11. At the protein level, these mutations lead to the same end result: in-frame loss and insertion of a number of amino acids and could be considered examples of deletion-insertion. Although proper description of these mutations at the genomic level is a complex task and requires an individual approach, the uniform name deletion-inversion is suggested for this type of mutation, based on the present study. The frequency of deletion-inversions among KIT exon 11 mutant GISTs was estimated to be <0.5%, based on evaluation of 700 KIT exon 11 mutants. Molecular events leading to formation of deletion-inversions remain elusive and should be studied further.

  5. STUDY OF ECK GENE EXON-3 FROM HUMAN NORMAL TISSUE AND BREAST CANCER CELL LINE

    Institute of Scientific and Technical Information of China (English)

    李瑶琛; 孔令洪; 王一理; 司履生

    2003-01-01

    Objective To establish a method cloning the exon 3 of eck gene from normal tissue and ZR-75-1 cell line (a human breast cancer cell line)and study whether these genes exist mutant. Methods Designed a pair of specific primers and amplified the exon 3 of eck gene fragment from the extracted genomic DNA derived from normal epithelial cells from skin tissue and ZR-75-1 cell line respectively by PCR technique. Transformed the E.coil. JM109 with recombinant plamids constructed by inserting the amplified fragments into medium vector pUCm-T and sequenced these amplified fragments after primary screening of endonuclease restriction digestion and PCR amplification. Results ① Obtained the genomic DNA of human normal epithelial cells and ZR-75-1 cell line respectively. ② Obtained the amplified fragments of human exon 3 of eck gene through PCR technique. ③ Obtained the cloning vectors of exon 3 of eck gene of human normal epithelial cells and ZR-75-1 cell line respectively. ④ ZR-75-1 cell line exists mutation of nucleotides. Conclusion Successfully established the method of cloning the human exon 3 of eck gene and found some mutations in the detected samples. This study lays a foundation for further studying the function of eck gene in tumorgenesis.

  6. Implementation of exon arrays: alternative splicing during T-cell proliferation as determined by whole genome analysis

    Directory of Open Access Journals (Sweden)

    Whistler Toni

    2010-09-01

    Full Text Available Abstract Background The contribution of alternative splicing and isoform expression to cellular response is emerging as an area of considerable interest, and the newly developed exon arrays allow for systematic study of these processes. We use this pilot study to report on the feasibility of exon array implementation looking to replace the 3' in vitro transcription expression arrays in our laboratory. One of the most widely studied models of cellular response is T-cell activation from exogenous stimulation. Microarray studies have contributed to our understanding of key pathways activated during T-cell stimulation. We use this system to examine whole genome transcription and alternate exon usage events that are regulated during lymphocyte proliferation in an attempt to evaluate the exon arrays. Results Peripheral blood mononuclear cells form healthy donors were activated using phytohemagglutinin, IL2 and ionomycin and harvested at 5 points over a 7 day period. Flow cytometry measured cell cycle events and the Affymetrix exon array platform was used to identify the gene expression and alternate exon usage changes. Gene expression changes were noted in a total of 2105 transcripts, and alternate exon usage identified in 472 transcript clusters. There was an overlap of 263 transcripts which showed both differential expression and alternate exon usage over time. Gene ontology enrichment analysis showed a broader range of biological changes in biological processes for the differentially expressed genes, which include cell cycle, cell division, cell proliferation, chromosome segregation, cell death, component organization and biogenesis and metabolic process ontologies. The alternate exon usage ontological enrichments are in metabolism and component organization and biogenesis. We focus on alternate exon usage changes in the transcripts of the spliceosome complex. The real-time PCR validation rates were 86% for transcript expression and 71% for

  7. Evidence for association of multi-exon skipping events with tumors

    Institute of Scientific and Technical Information of China (English)

    Jianning BI; Tao PENG; Yanda LI

    2008-01-01

    Alternative splicing(AS)has been shown to be frequently present in human tumors.Specifically,it has been observed in some experimental studies that multi-exon skipping(MES)events often appear in tumorous tissues.Prompted by this observation,we conducted a genomewide analysis of MES events to investigate their association with tumors.The results show that MES events are more likely associated with tumors than single-exon skipping (SES) and the degree of association increases with the number of skipped exons.Furthermore,MES events are found to be less conserved than their SES counterparts,which provides additional evidence for our results because disease-associated AS events should be eliminated during evolution.Interestingly,these differences still existed even after comparison Of MES and SES events with similarlength skipped regions.These results demonstrate that MES events mav be associated with tumors and suggest that MES isoforms might be useful in cancer diagnosis.

  8. Molecular evolution of the leptin exon 3 in some species of the family Canidae

    Directory of Open Access Journals (Sweden)

    Switonski Marek

    2003-09-01

    Full Text Available Abstract The structure of the leptin gene seems to be well conserved. The polymorphism of this gene in four species belonging to the Canidae family (the dog (Canis familiaris – 16 different breeds, the Chinese racoon dog (Nyctereutes procyonoides procyonoides, the red fox (Vulpes vulpes and the arctic fox (Alopex lagopus were studied with the use of single strand conformation polymorphism (SSCP, restriction fragment length polymorphism (RFLP and DNA sequencing techniques. For exon 2, all species presented the same SSCP pattern, while in exon 3 some differences were found. DNA sequencing of exon 3 revealed the presence of six nucleotide substitutions, differentiating the studied species. Three of them cause amino acid substitutions as well. For all dog breeds studied, SSCP patterns were identical.

  9. AA Amyloidosis and Atypical Familial Mediterranean Fever with Exon 2 and 3 Mutations

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    Junko Yabuuchi

    2017-07-01

    Full Text Available A 54-year-old Japanese man presented with recurrent abdominal pain, fever lasting >5 days, and renal failure. AA amyloidosis was proven by renal and gastric biopsy. Symptoms subsided with the administration of colchicine, but a subsequent recurrence of symptoms did not respond to colchicine. Mediterranean fever gene (MEFV analysis showed that he was heterozygous for mutations in exon 2 (E148Q/R202Q and exon 3 (P369S/R408Q, although he had none of the exon 10 mutations known to be closely related to AA amyloidosis. He did not respond to infliximab, but tocilizumab therapy was successful. The present case is a rare report of AA amyloidosis associated with familial Mediterranean fever in Japan.

  10. Exon-primed intron-crossing (EPIC markers as a tool for ant phylogeography

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    Patrícia R. Ströher

    2013-12-01

    Full Text Available Exon-primed intron-crossing (EPIC markers as a tool for ant phylogeography. Due to their local abundance, diversity of adaptations and worldwide distribution, ants are a classic example of adaptive radiation. Despite this evolutionary and ecological importance, phylogeographical studies on ants have relied largely on mitochondrial markers. In this study we design and test exon-primed intron-crossing (EPIC markers, which can be widely used to uncover ant intraspecific variation. Candidate markers were obtained through screening the available ant genomes for unlinked conserved exonic regions interspersed with introns. A subset of 15 markers was tested in vitro and showed successful amplification in several phylogenetically distant ant species. These markers represent an important step forward in ant phylogeography and population genetics, allowing for more extensive characterization of variation in ant nuclear DNA without the need to develop species-specific markers.

  11. Exonal deletion of SLC24A4 causes hypomaturation amelogenesis imperfecta.

    Science.gov (United States)

    Seymen, F; Lee, K-E; Tran Le, C G; Yildirim, M; Gencay, K; Lee, Z H; Kim, J-W

    2014-04-01

    Amelogenesis imperfecta is a heterogeneous group of genetic conditions affecting enamel formation. Recently, mutations in solute carrier family 24 member 4 (SLC24A4) have been identified to cause autosomal recessive hypomaturation amelogenesis imperfecta. We recruited a consanguineous family with hypomaturation amelogenesis imperfecta with generalized brown discoloration. Sequencing of the candidate genes identified a 10-kb deletion, including exons 15, 16, and most of the last exon of the SLC24A4 gene. Interestingly, this deletion was caused by homologous recombination between two 354-bp-long homologous sequences located in intron 14 and the 3' UTR. This is the first report of exonal deletion in SLC24A4 providing confirmatory evidence that the function of SLC24A4 in calcium transport has a crucial role in the maturation stage of amelogenesis.

  12. Benign familial neonatal convulsions caused by mutation in KCNQ3, exon 6: a European case.

    Science.gov (United States)

    Fister, Petja; Soltirovska-Salamon, Aneta; Debeljak, Marusa; Paro-Panjan, Darja

    2013-05-01

    Benign familial neonatal convulsions (BFNC) is a rare, clinically and genetically heterogenous epileptic disorder. Two voltage gated potassium genes, KCNQ2 and KCNQ3, have been identified as genes responsible for BFNC1 and BFNC2 respectively. While as many as 73 mutations of KCNQ2 have been described up to date, only 4 mutations in KCNQ3, 3 of them appearing in exon 5, have been identified. Mutation in exon 6 was found for the first time in a Chinese family, and here we report the same missense mutation of KCNQ3 within exon 6 in a Caucasian family, whose history and clinical picture were in accordance with BFNC. Copyright © 2012 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  13. Abnormal Methylation Status of the GNAS Exon 1A Region in Pseudohypohyperparathyroidism Combined With Turner Syndrome.

    Science.gov (United States)

    Zhu, Jie; Wang, Dong; Ren, An; Xing, Yan; Zhang, Dongliang; Wei, Jun; Yu, Ning; Xing, Xuenong; Ye, Shandong

    2015-12-01

    Pseudohypohyperparathyroidism (PHHP) is a rare type of pseudohypoparathyroidism (PHP), which seems to have a normal skeletal response to parathyroid hormone but shows renal resistance. Almost all patients with PHHP have PHP Ib, a subtype of PHP that is usually caused by GNAS methylation defects, often in exon 1A. Some features of Albright hereditary osteodystrophy can occasionally be found in patients with PHHP, but these features are also common in Turner syndrome. The authors report on an extremely rare case of a patient with PHHP and Turner syndrome, a 47-year-old woman who sought medical attention for hypocalcemia and elevated parathyroid hormone. She had no family history of hypocalcemia and no STX16 gene deletions. She had a mosaic karyotype of 46, X, del(X)(p11.4)/45, XO. Pyrosequencing was performed to determine the GNAS exon 1A methylation. The degree of methylation found in exon 1A of the patient was lower than her unaffected relatives.

  14. Role of the intracellular receptor domain of gp130 (exon 17) in human inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    Christoph J. Auernhammer; Thomas Ochsenkühn; Kathrin Zitzmann; Fabian Schnitzler; Julia Seiderer; Peter Lohse; George Vlotides; Dieter Engelhardt; Michael Sackmann; Burkhard G(o)ke

    2005-01-01

    AIM: To study the role of the intracellular receptor domain of gp130 in human inflammatory bowel disease (IBD).METHODS: We amplified and sequenced the complete exon 17 of the human gp130 gene in 146 patients with IBD. According to clinical and histopathological signs,the 146 patients with IBD were classified as having Crohn's disease (n = 73) or ulcerative colitis (n = 63),or as indeterminate status (n = 10).RESULTS: No mutations in exon 17 of the gp130 gene could be detected in any of the 146 patients with IBD examined.CONCLUSION: There is no evidence that mutations in exon 17 of the gp130 gene are involved in the pathogenesis of human IBD.

  15. Computational analysis and prediction for exons of PAC579 genomic sequence

    Institute of Scientific and Technical Information of China (English)

    黄弋; 覃文新; 万大方; 赵新泰; 顾健人

    2001-01-01

    To isolate the novel genes related to human hepatocellular carcinoma (HCC), we sequenced P1-derived artificial chromosome PAC579 (D17S926 locus) mapped in the minimum LOH (loss of heterozygosity) deletion region of chromosome 17p13.3 in HCC, Four novel genes mapped in this genomic sequence area were isolated and cloned by wet-lab experiments, and the exons of these genes were located. 0-60 kb of this genomic sequence including the genes of interest was scanned with five different computational exon prediction programs as well as four splice site recognition programs. After analyzing and comparing the computationally predicted results with the wet-lab experiment results, some potential exons were predicted in the genomic sequence by using these programs.

  16. Histone modifications involved in cassette exon inclusions: a quantitative and interpretable analysis.

    Science.gov (United States)

    Liu, Hui; Jin, Ting; Guan, Jihong; Zhou, Shuigeng

    2014-12-19

    Chromatin structure and epigenetic modifications have been shown to involve in the co-transcriptional splicing of RNA precursors. In particular, some studies have suggested that some types of histone modifications (HMs) may participate in the alternative splicing and function as exon marks. However, most existing studies pay attention to the qualitative relationship between epigenetic modifications and exon inclusion. The quantitative analysis that reveals to what extent each type of epigenetic modification is responsible for exon inclusion is very helpful for us to understand the splicing process. In this paper, we focus on the quantitative analysis of HMs' influence on the inclusion of cassette exons (CEs) into mature RNAs. With the high-throughput ChIP-seq and RNA-seq data obtained from ENCODE website, we modeled the association of HMs with CE inclusions by logistic regression whose coefficients are meaningful and interpretable for us to reveal the effect of each type of HM. Three type of HMs, H3K36me3, H3K9me3 and H4K20me1, were found to play major role in CE inclusions. HMs' effect on CE inclusions is conservative across cell types, and does not depend on the expression levels of the genes hosting CEs. HMs located in the flanking regions of CEs were also taken into account in our analysis, and HMs within bounded flanking regions were shown to affect moderately CE inclusions. Moreover, we also found that HMs on CEs whose length is approximately close to nucleosomal-DNA length affect greatly on CE inclusion. We suggested that a few types of HMs correlate closely to alternative splicing and perhaps function jointly with splicing machinery to regulate the inclusion level of exons. Our findings are helpful to understand HMs' effect on exon definition, as well as the mechanism of co-transcriptional splicing.

  17. Multi-exon deletions of the FBN1 gene in Marfan syndrome

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    Schrijver Iris

    2001-10-01

    Full Text Available Abstract Background Mutations in the fibrillin -1 gene (FBN1 cause Marfan syndrome (MFS, an autosomal dominant multi-system connective tissue disorder. The 200 different mutations reported in the 235 kb, 65 exon-containing gene include only one family with a genomic multi-exon deletion. Methods We used long-range RT-PCR for mutation detection and long-range genomic PCR and DNA sequencing for identification of deletion breakpoints, allele-specific transcript analyses to determine stability of the mutant RNA, and pulse-chase studies to quantitate fibrillin synthesis and extracellular matrix deposition in cultured fibroblasts. Southern blots of genomic DNA were probed with three overlapping fragments covering the FBN1 coding exons Results Two novel multi-exon FBN1 deletions were discovered. Identical nucleotide pentamers were found at or near the intronic breakpoints. In a Case with classic MFS, an in-frame deletion of exons 42 and 43 removed the C-terminal 24 amino acids of the 5th LTBP (8-cysteine domain and the adjacent 25th calcium-binding EGF-like (6-cysteine domain. The mutant mRNA was stable, but fibrillin synthesis and matrix deposition were significantly reduced. A Case with severe childhood-onset MFS has a de novo deletion of exons 44–46 that removed three EGF-like domains. Fibrillin protein synthesis was normal, but matrix deposition was strikingly reduced. No genomic rearrangements were detected by Southern analysis of 18 unrelated MFS samples negative for FBN1 mutation screening. Conclusions Two novel deletion cases expand knowledge of mutational mechanisms and genotype/phenotype correlations of fibrillinopathies. Deletions or mutations affecting an LTBP domain may result in unstable mutant protein cleavage products that interfere with microfibril assembly.

  18. Characterization of major histocompatibility complex (MHC DRB exon 2 and DRA exon 3 fragments in a primary terrestrial rabies vector (Procyon lotor.

    Directory of Open Access Journals (Sweden)

    Sarrah Castillo

    Full Text Available The major histocompatibility complex (MHC presents a unique system to explore links between genetic diversity and pathogens, as diversity within MHC is maintained in part by pathogen driven selection. While the majority of wildlife MHC studies have investigated species that are of conservation concern, here we characterize MHC variation in a common and broadly distributed species, the North American raccoon (Procyon lotor. Raccoons host an array of broadly distributed wildlife diseases (e.g., canine distemper, parvovirus and raccoon rabies virus and present important human health risks as they persist in high densities and in close proximity to humans and livestock. To further explore how genetic variation influences the spread and maintenance of disease in raccoons we characterized a fragment of MHC class II DRA exon 3 (250 bp and DRB exon 2 (228 bp. MHC DRA was found to be functionally monomorphic in the 32 individuals screened; whereas DRB exon 2 revealed 66 unique alleles among the 246 individuals screened. Between two and four alleles were observed in each individual suggesting we were amplifying a duplicated DRB locus. Nucleotide differences between DRB alleles ranged from 1 to 36 bp (0.4-15.8% divergence and translated into 1 to 21 (1.3-27.6% divergence amino acid differences. We detected a significant excess of nonsynonymous substitutions at the peptide binding region (P = 0.005, indicating that DRB exon 2 in raccoons has been influenced by positive selection. These data will form the basis of continued analyses into the spatial and temporal relationship of the raccoon rabies virus and the immunogenetic response in its primary host.

  19. Identification of conserved splicing motifs in mutually exclusive exons of 15 insect species.

    Science.gov (United States)

    Buendia, Patricia; Tyree, John; Loredo, Robert; Hsu, Shu-Ning

    2012-04-12

    During alternative splicing, the inclusion of an exon in the final mRNA molecule is determined by nuclear proteins that bind cis-regulatory sequences in a target pre-mRNA molecule. A recent study suggested that the regulatory codes of individual RNA-binding proteins may be nearly immutable between very diverse species such as mammals and insects. The model system Drosophila melanogaster therefore presents an excellent opportunity for the study of alternative splicing due to the availability of quality EST annotations in FlyBase. In this paper, we describe an in silico analysis pipeline to extract putative exonic splicing regulatory sequences from a multiple alignment of 15 species of insects. Our method, ESTs-to-ESRs (E2E), uses graph analysis of EST splicing graphs to identify mutually exclusive (ME) exons and combines phylogenetic measures, a sliding window approach along the multiple alignment and the Welch's t statistic to extract conserved ESR motifs. The most frequent 100% conserved word of length 5 bp in different insect exons was "ATGGA". We identified 799 statistically significant "spike" hexamers, 218 motifs with either a left or right FDR corrected spike magnitude p-value < 0.05 and 83 with both left and right uncorrected p < 0.01. 11 genes were identified with highly significant motifs in one ME exon but not in the other, suggesting regulation of ME exon splicing through these highly conserved hexamers. The majority of these genes have been shown to have regulated spatiotemporal expression. 10 elements were found to match three mammalian splicing regulator databases. A putative ESR motif, GATGCAG, was identified in the ME-13b but not in the ME-13a of Drosophila N-Cadherin, a gene that has been shown to have a distinct spatiotemporal expression pattern of spliced isoforms in a recent study. Analysis of phylogenetic relationships and variability of sequence conservation as implemented in the E2E spikes method may lead to improved identification of ESRs

  20. MX1 exon 13 polymorphisms in broiler breeder chickens and associations with commercial traits.

    Science.gov (United States)

    Livant, E J; Avendano, S; McLeod, S; Ye, X; Lamont, S J; Dekkers, J C M; Ewald, S J

    2007-04-01

    The Mx1 gene in mice is induced by type I interferons and is the major determinant of resistance to influenza virus and related orthomyxoviruses. It has been previously shown that a SNP in exon 13 of the chicken MX1 gene determines differential antiviral activity of the protein. We evaluated this SNP and two additional SNPs in elite broiler lines by PCR amplification and sequence analysis. Associations between MX1 exon 13 SNPs and several traits of economic interest were evaluated. Significant associations were found between the SNP determining antiviral activity and mortality in one line and leg defects in another line.

  1. A modified group I intron can function as both a ribozyme and a 5' exon in a trans-exon ligation reaction.

    Science.gov (United States)

    Tasiouka, K I; Burke, J M

    1994-06-24

    Here, we show that a single RNA molecule derived from a group-I intron can provide the catalytic activity, the substrate recognition domain and the attacking nucleophile in a reaction that mimics the exon ligation step of splicing. To accomplish this reaction, we have linked a 5' exon sequence to the 3' end of an attenuated form of the self-splicing Tetrahymena rRNA intron. The ribozyme (I-E1) attacks an oligoribonucleotide analog of the 3' splice site (I'-E2) to generate a product containing ligated exons (I-E1-E2) and a small intron fragment (I'). Two modified introns were constructed and tested for activity. A construct designed to interact with the 3' splice site through intermolecular P9.0 and P10 helices was found to be inactive due to failure to form a stable ribozyme-substrate complex. A second modified intron and substrate combination was engineered, in which the complex was further stabilized by an intermolecular P9.2 helix. In this case, stable complexes and reaction products were identified. The reaction efficiency was low compared to splicing of the unmodified intron-containing precursor, and will be optimized in future experiments. Following optimization, we believe that this system may be exploited to examine the functional consequences of a wide variety of 3' splice-site modifications, and may provide the basis for development of highly selective trans-acting ribozymes.

  2. De novo exonic mutation in MYH7 gene leading to exon skipping in a patient with early onset muscular weakness and fiber-type disproportion.

    Science.gov (United States)

    Pajusalu, Sander; Talvik, Inga; Noormets, Klari; Talvik, Tiina; Põder, Haide; Joost, Kairit; Puusepp, Sanna; Piirsoo, Andres; Stenzel, Werner; Goebel, Hans H; Nikopensius, Tiit; Annilo, Tarmo; Nõukas, Margit; Metspalu, Andres; Õunap, Katrin; Reimand, Tiia

    2016-03-01

    Here we report on a case of MYH7-related myopathy in a boy with early onset of muscular weakness and delayed motor development in infancy. His most affected muscles were neck extensors showing a dropped head sign, proximal muscles of lower limbs with positive Gower's sign, and trunk muscles. Brain and spinal cord MRI scans, echocardiography, and laboratory analyses including creatine kinase and lactate did not reveal any abnormalities. Muscle histopathology showed fiber-type disproportion. Whole exome sequencing of the parents-offspring trio revealed a novel de novo c.5655G>A p.(Ala1885=) synonymous substitution of the last nucleotide in exon 38 of the MYH7 gene. Further RNA investigations proved the skipping of exon 38 (p.1854_1885del). This is a first report of an exon-skipping mutation in the MYH7 gene causing myopathy. This report broadens both the phenotypic and genotypic spectra of MYH7-related myopathies. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Antisense PMO found in dystrophic dog model was effective in cells from exon 7-deleted DMD patient.

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    Takashi Saito

    Full Text Available BACKGROUND: Antisense oligonucleotide-induced exon skipping is a promising approach for treatment of Duchenne muscular dystrophy (DMD. We have systemically administered an antisense phosphorodiamidate morpholino oligomer (PMO targeting dystrophin exons 6 and 8 to a dog with canine X-linked muscular dystrophy in Japan (CXMD(J lacking exon 7 and achieved recovery of dystrophin in skeletal muscle. To date, however, antisense chemical compounds used in DMD animal models have not been directly applied to a DMD patient having the same type of exon deletion. We recently identified a DMD patient with an exon 7 deletion and tried direct translation of the antisense PMO used in dog models to the DMD patient's cells. METHODOLOGY/PRINCIPAL FINDINGS: We converted fibroblasts of CXMD(J and the DMD patient to myotubes by FACS-aided MyoD transduction. Antisense PMOs targeting identical regions of dog and human dystrophin exons 6 and 8 were designed. These antisense PMOs were mixed and administered as a cocktail to either dog or human cells in vitro. In the CXMD(J and human DMD cells, we observed a similar efficacy of skipping of exons 6 and 8 and a similar extent of dystrophin protein recovery. The accompanying skipping of exon 9, which did not alter the reading frame, was different between cells of these two species. CONCLUSION/SIGNIFICANCE: Antisense PMOs, the effectiveness of which has been demonstrated in a dog model, achieved multi-exon skipping of dystrophin gene on the FACS-aided MyoD-transduced fibroblasts from an exon 7-deleted DMD patient, suggesting the feasibility of systemic multi-exon skipping in humans.

  4. Antisense PMO found in dystrophic dog model was effective in cells from exon 7-deleted DMD patient.

    Science.gov (United States)

    Saito, Takashi; Nakamura, Akinori; Aoki, Yoshitsugu; Yokota, Toshifumi; Okada, Takashi; Osawa, Makiko; Takeda, Shin'ichi

    2010-08-18

    Antisense oligonucleotide-induced exon skipping is a promising approach for treatment of Duchenne muscular dystrophy (DMD). We have systemically administered an antisense phosphorodiamidate morpholino oligomer (PMO) targeting dystrophin exons 6 and 8 to a dog with canine X-linked muscular dystrophy in Japan (CXMD(J)) lacking exon 7 and achieved recovery of dystrophin in skeletal muscle. To date, however, antisense chemical compounds used in DMD animal models have not been directly applied to a DMD patient having the same type of exon deletion. We recently identified a DMD patient with an exon 7 deletion and tried direct translation of the antisense PMO used in dog models to the DMD patient's cells. We converted fibroblasts of CXMD(J) and the DMD patient to myotubes by FACS-aided MyoD transduction. Antisense PMOs targeting identical regions of dog and human dystrophin exons 6 and 8 were designed. These antisense PMOs were mixed and administered as a cocktail to either dog or human cells in vitro. In the CXMD(J) and human DMD cells, we observed a similar efficacy of skipping of exons 6 and 8 and a similar extent of dystrophin protein recovery. The accompanying skipping of exon 9, which did not alter the reading frame, was different between cells of these two species. Antisense PMOs, the effectiveness of which has been demonstrated in a dog model, achieved multi-exon skipping of dystrophin gene on the FACS-aided MyoD-transduced fibroblasts from an exon 7-deleted DMD patient, suggesting the feasibility of systemic multi-exon skipping in humans.

  5. Exon definition complexes contain the tri-snRNP and can be directly converted into B-like precatalytic splicing complexes.

    OpenAIRE

    Schneider, M.; Will, C.; Anokhina, M.; Tazi, J; Urlaub, H; Lührmann, R

    2010-01-01

    The first step in splicing of pre-mRNAs with long introns is exon definition, where U1 and U2 snRNPs bind at opposite ends of an exon. After exon definition, these snRNPs must form a complex across the upstream intron to allow splicing catalysis. Exon definition and conversion of cross-exon to cross-intron spliceosomal complexes are poorly understood. Here we demonstrate that, in addition to U1 and U2 snRNPs, cross-exon complexes contain U4, U5, and U6 (which form the tri-snRNP). Tri-snRNP do...

  6. Cryptic exon incorporation occurs in Alzheimer's brain lacking TDP-43 inclusion but exhibiting nuclear clearance of TDP-43.

    Science.gov (United States)

    Sun, Mingkuan; Bell, William; LaClair, Katherine D; Ling, Jonathan P; Han, Heather; Kageyama, Yusuke; Pletnikova, Olga; Troncoso, Juan C; Wong, Philip C; Chen, Liam L

    2017-06-01

    Abnormal accumulation of TDP-43 into cytoplasmic or nuclear inclusions with accompanying nuclear clearance, a common pathology initially identified in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), has also been found in Alzheimer' disease (AD). TDP-43 serves as a splicing repressor of nonconserved cryptic exons and that such function is compromised in brains of ALS and FTD patients, suggesting that nuclear clearance of TDP-43 underlies its inability to repress cryptic exons. However, whether TDP-43 cytoplasmic aggregates are a prerequisite for the incorporation of cryptic exons is not known. Here, we assessed hippocampal tissues from 34 human postmortem brains including cases with confirmed diagnosis of AD neuropathologic changes along with age-matched controls. We found that cryptic exon incorporation occurred in all AD cases exhibiting TDP-43 pathology. Furthermore, incorporation of cryptic exons was observed in the hippocampus when TDP-43 inclusions was restricted only to the amygdala, the earliest stage of TDP-43 progression. Importantly, cryptic exon incorporation could be detected in AD brains lacking TDP-43 inclusion but exhibiting nuclear clearance of TDP-43. These data supports the notion that the functional consequence of nuclear depletion of TDP-43 as determined by cryptic exon incorporation likely occurs as an early event of TDP-43 proteinopathy and may have greater contribution to the pathogenesis of AD than currently appreciated. Early detection and effective repression of cryptic exons in AD patients may offer important diagnostic and therapeutic implications for this devastating illness of the elderly.

  7. Integrated exon level expression analysis of driver genes explain their role in colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Mohammad Azhar Aziz

    Full Text Available Integrated analysis of genomic and transcriptomic level changes holds promise for a better understanding of colorectal cancer (CRC biology. There is a pertinent need to explain the functional effect of genome level changes by integrating the information at the transcript level. Using high resolution cytogenetics array, we had earlier identified driver genes by 'Genomic Identification of Significant Targets In Cancer (GISTIC' analysis of paired tumour-normal samples from colorectal cancer patients. In this study, we analyze these driver genes at three levels using exon array data--gene, exon and network. Gene level analysis revealed a small subset to experience differential expression. These results were reinforced by carrying out separate differential expression analyses (SAM and LIMMA. ATP8B1 was found to be the novel gene associated with CRC that shows changes at cytogenetic, gene and exon levels. Splice index of 29 exons corresponding to 13 genes was found to be significantly altered in tumour samples. Driver genes were used to construct regulatory networks for tumour and normal groups. There were rearrangements in transcription factor genes suggesting the presence of regulatory switching. The regulatory pattern of AHR gene was found to have the most significant alteration. Our results integrate data with focus on driver genes resulting in highly enriched novel molecules that need further studies to establish their role in CRC.

  8. A novel first exon directs hormone-sensitive transcription of the pig prolactin receptor

    Science.gov (United States)

    Endocrine, paracrine, and autocrine prolactin (PRL) acts through its receptor (PRLR) to confer a wide range of biological functions, including its established role during lactation.We have identified a novel first exon of the porcine PRLR that gives rise to three different mRNA transcripts. Transcri...

  9. Antisense oligonucleotide-mediated exon skipping as a strategy to reduce proteolytic cleavage of ataxin-3.

    Science.gov (United States)

    Toonen, Lodewijk J A; Schmidt, Iris; Luijsterburg, Martijn S; van Attikum, Haico; van Roon-Mom, Willeke M C

    2016-10-12

    Spinocerebellar ataxia type-3 (SCA3) is a neurodegenerative disorder caused by a polyglutamine repeat expansion in the ataxin-3 protein. Cleavage of mutant ataxin-3 by proteolytic enzymes yields ataxin-3 fragments containing the polyglutamine stretch. These shorter ataxin-3 fragments are thought to be involved in SCA3 pathogenesis due to their increased cellular toxicity and their involvement in formation of the characteristic neuronal aggregates. As a strategy to prevent formation of toxic cleavage fragments, we investigated an antisense oligonucleotide-mediated modification of the ataxin-3 pre-mRNA through exon skipping of exon 8 and 9, resulting in the removal of a central 88 amino acid region of the ataxin-3 protein. This removed protein region contains several predicted cleavage sites and two ubiquitin-interacting motifs. In contrast to unmodified mutant ataxin-3, the internally truncated ataxin-3 protein did not give rise to potentially toxic cleavage fragments when incubated with caspases. In vitro experiments did not show cellular toxicity of the modified ataxin-3 protein. However, the modified protein was incapable of binding poly-ubiquitin chains, which may interfere with its normal deubiquitinating function. Low exon skipping efficiencies combined with reduction in important ataxin-3 protein functions suggest that skipping of exon 8 and 9 is not a viable therapeutic option for SCA3.

  10. Refinement of antisense oligonucleotide mediated exon skipping as therapy for Duchenne muscular dystrophy

    NARCIS (Netherlands)

    Heemskerk, Johannes Antonius

    2011-01-01

    In recent years, modulation of mRNA has emerged as a promising therapeutic tool. For instance, in the field of neuromuscular disorders therapeutic strategies are being developed for several diseases, including antisense oligonucleotide (AON) mediated exon skipping for Duchenne Muscular Dystrophy (DM

  11. Detection EGFR exon 19 status of lung cancer patients by DNA electrochemical biosensor.

    Science.gov (United States)

    Xu, Xiong-Wei; Weng, Xiu-Hua; Wang, Chang-Lian; Lin, Wei-Wei; Liu, Ai-Lin; Chen, Wei; Lin, Xin-Hua

    2016-06-15

    Epidermal growth factor receptor (EGFR) exon 19 mutation status is a very important prediction index for tyrosine kinase inhibitors (TKIs) therapy. In this paper, we constructed a superior selective sandwich-type electrochemical biosensor to detect in-frame deletions in exon 19 of EGFR in real samples of patients with non-small cell lung carcinoma. Based on the characteristics of different hybridization efficiency in different hybridization phase conditions, different region around EGFR exon 19 deletion hotspots was selected to design DNA probes to improve biosensor performance. The results confirm that alteration of deletion location in target deliberately according to different hybridization phase is able to improve selectivity of sandwich-type DNA biosensor. Satisfactory discrimination ability can be achieved when the deletions are located in the capture probe interaction region. In order to improve efficiency of ssDNA generation from dsDNA, we introduce Lambda exonuclease (λ-exo) to sandwich-type biosensor system. EGFR exon 19 statuses of clinical real samples from lung cancer patients can be discriminated successfully by the proposed method. Our research would make the electrochemical biosensor be an excellent candidate for EGFR detection for lung cancer patients.

  12. Refinement of antisense oligonucleotide mediated exon skipping as therapy for Duchenne muscular dystrophy

    NARCIS (Netherlands)

    Heemskerk, Johannes Antonius

    2011-01-01

    In recent years, modulation of mRNA has emerged as a promising therapeutic tool. For instance, in the field of neuromuscular disorders therapeutic strategies are being developed for several diseases, including antisense oligonucleotide (AON) mediated exon skipping for Duchenne Muscular Dystrophy (DM

  13. A systematic, large-scale resequencing screen of X-chromosome coding exons in mental retardation.

    NARCIS (Netherlands)

    Tarpey, P.S.; Smith, R.; Pleasance, E.; Whibley, A.; Edkins, S.; Hardy, C.; O'Meara, S.; Latimer, C.; Dicks, E.; Menzies, A.; Stephens, P.; Blow, M.; Greenman, C.; Xue, Y.; Tyler-Smith, C.; Thompson, D.; Gray, K.; Andrews, J.; Barthorpe, S.; Buck, G.; Cole, J.; Dunmore, R.; Jones, D.; Maddison, M.; Mironenko, T.; Turner, R.; Turrell, K.; Varian, J.; West, S.; Widaa, S.; Wray, P.; Teague, J.; Butler, A.; Jenkinson, A.; Jia, M.; Richardson, D.; Shepherd, R.; Wooster, R.; Tejada, M.I.; Martinez, F.; Carvill, G.; Goliath, R.; Brouwer, A.P.M. de; Bokhoven, H. van; Esch, H. van; Chelly, J.; Raynaud, M.; Ropers, H.H.; Abidi, F.E.; Srivastava, A.K.; Cox, J.; Luo, Y.; Mallya, U.; Moon, J.; Parnau, J.; Mohammed, S.; Tolmie, J.L.; Shoubridge, C.; Corbett, M.; Gardner, A.; Haan, E.; Rujirabanjerd, S.; Shaw, M.A.; Vandeleur, L.; Fullston, T.; Easton, D.F.; Boyle, J.; Partington, M.; Hackett, A.; Field, M.; Skinner, C.; Stevenson, R.E.; Bobrow, M.; Turner, G.; Schwartz, C.E.; Gecz, J.; Raymond, F.L.; Futreal, P.A.; Stratton, M.R.

    2009-01-01

    Large-scale systematic resequencing has been proposed as the key future strategy for the discovery of rare, disease-causing sequence variants across the spectrum of human complex disease. We have sequenced the coding exons of the X chromosome in 208 families with X-linked mental retardation (XLMR),

  14. Improvements to previous algorithms to predict gene structure and isoform concentrations using Affymetrix Exon arrays

    Directory of Open Access Journals (Sweden)

    Aramburu Ander

    2010-11-01

    Full Text Available Abstract Background Exon arrays provide a way to measure the expression of different isoforms of genes in an organism. Most of the procedures to deal with these arrays are focused on gene expression or on exon expression. Although the only biological analytes that can be properly assigned a concentration are transcripts, there are very few algorithms that focus on them. The reason is that previously developed summarization methods do not work well if applied to transcripts. In addition, gene structure prediction, i.e., the correspondence between probes and novel isoforms, is a field which is still unexplored. Results We have modified and adapted a previous algorithm to take advantage of the special characteristics of the Affymetrix exon arrays. The structure and concentration of transcripts -some of them possibly unknown- in microarray experiments were predicted using this algorithm. Simulations showed that the suggested modifications improved both specificity (SP and sensitivity (ST of the predictions. The algorithm was also applied to different real datasets showing its effectiveness and the concordance with PCR validated results. Conclusions The proposed algorithm shows a substantial improvement in the performance over the previous version. This improvement is mainly due to the exploitation of the redundancy of the Affymetrix exon arrays. An R-Package of SPACE with the updated algorithms have been developed and is freely available.

  15. Concurrent mutation in exons 1 and 2 of the K-ras oncogene in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Fiorella Guadagni

    2012-01-01

    Full Text Available The K-ras gene is frequently mutated in colorectal cancer and has been associated with tumor initiation and progression; approximately 90% of the activating mutations are found in codons 12 and 13 of exon 1 and just under 5% in codon 61 located in exon 2. These mutations determine single aminoacidic substitutions in the GTPase pocket leading to a block of the GTP hydrolytic activity of the K-ras p21 protein, and therefore to its constitutive activation. Point mutations in sites of the K-ras gene, other than codons 12, 13 and 61, and other types of genetic alterations, may occur in a minority of cases, such as in the less frequent cases of double mutations in the K-ras gene. However, all mutations in this gene, even those which occur in non-canonical sites or double mutations, are relevant oncogenic alterations in colorectal cancer and may underlie K-ras pathway hyperactivation. In the present study, we report the case of a patient with colorectal cancer presenting a concurrent point mutation in exons 1 and 2 of the K-ras gene, a GGT to TGT substitution (Glycine to Cysteine at codon 12, and a GAC to AAC substitution (Aspartic Acid to Asparagine at codon 57. In addition, we found in the same patient’s sample a silent polymorphism at codon 11 (Ala11Ala of exon 1. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 729–733

  16. Concurrent mutation in exons 1 and 2 of the K-ras oncogene in colorectal cancer.

    Science.gov (United States)

    Palmirotta, Raffaele; Savonarola, Annalisa; Ludovici, Giorgia; De Marchis, Maria Laura; Covello, Renato; Ettorre, Giuseppe Maria; Ialongo, Cristiano; Guadagni, Fiorella

    2011-01-01

    The K-ras gene is frequently mutated in colorectal cancer and has been associated with tumor initiation and progression; approximately 90% of the activating mutations are found in codons 12 and 13 of exon 1 and just under 5% in codon 61 located in exon 2. These mutations determine single aminoacidic substitutions in the GTPase pocket leading to a block of the GTP hydrolytic activity of the K-ras p21 protein, and therefore to its constitutive activation. Point mutations in sites of the K-ras gene, other than codons 12, 13 and 61, and other types of genetic alterations, may occur in a minority of cases, such as in the less frequent cases of double mutations in the K-ras gene. However, all mutations in this gene, even those which occur in non-canonical sites or double mutations, are relevant oncogenic alterations in colorectal cancer and may underlie K-ras pathway hyperactivation. In the present study, we report the case of a patient with colorectal cancer presenting a concurrent point mutation in exons 1 and 2 of the K-ras gene, a GGT to TGT substitution (Glycine to Cysteine) at codon 12, and a GAC to AAC substitution (Aspartic Acid to Asparagine) at codon 57. In addition, we found in the same patient's sample a silent polymorphism at codon 11 (Ala11Ala) of exon 1.

  17. Intron 1 and exon 1 alpha estrogen receptor gene polymorphisms in women with endometriosis.

    Science.gov (United States)

    Sato, Hélio; Nogueira-de-Souza, Naiara C; D'Amora, Paulo; Silva, Ismael D C G; Girão, Manoel J B C; Schor, Eduardo

    2008-12-01

    To evaluate the association of intron 1 and exon 1 polymorphisms in the estrogen receptor alpha gene (ER-alpha) with endometriosis in women. Association study. Endometriosis Unit, Federal University of São Paulo. The control group consisted of volunteers older than 45 years who had no evidence of endometriosis antecedents. Two groups with the disease were evaluated: the first group had stage I or II endometriosis and the second group stage III or IV. Polymerase chain reaction (PCR) followed by digestion with HaeIII and MspI endonucleases (RFLP) were applied to detect intron 1 and exon 1 polymorphisms, respectively, in a total of 125 controls and 105 affected women. Frequency and distribution of HaeIII and MspI polymorphisms in ER-alpha. No significant differences in the frequency of polymorphisms either in intron 1 or exon 1 of ER-alpha were found when endometriosis patients were compared with control subjects. Furthermore, the frequency of ER-alpha polymorphisms within the two different groups of patients with disease was statistically similar. The odds ratio between presence of intron 1 single-nucleotide polymorphisms (SNP) and endometriosis was 0.904, and the odds ratio between exon 1 SNP and endometriosis was 0.976. The evaluated polymorphisms were not associated with endometriosis.

  18. Defining the ends of Parkin exon 4 deletions in two different families with Parkinson's disease.

    Science.gov (United States)

    Clarimon, Jordi; Johnson, Janel; Dogu, Okan; Horta, Wagner; Khan, Naheed; Lees, Andrew J; Hardy, John; Singleton, Andrew

    2005-02-05

    Autosomal recessive juvenile parkinsonism (AR-JP, PARK2) is characterized by an early onset parkinsonism, often presenting with dystonia as an early feature. Mutations in Parkin are a relatively common cause of AR-JP and are estimated to be present in approximately 30% of familial young onset Parkinson disease (PD) [Abbas et al. (1999); Hum Mol Genet 8:567-574]. These mutations include exon rearrangements (deletions and duplications), point mutations, and small deletions. Similar genomic mutations have been described in unrelated patients, thereby indicating independent mutational events or ancient founder effects. We have identified homozygous deletion mutations of exon 4 in Parkin in two unrelated families, one from Brazil and the other from Turkey [Dogu et al. (2004); Mov Dis 9:812-816; Khan et al., Mov Dis, in press]. We have performed molecular analysis of the deletion breakpoints and this data indicates these mutations originated independently. We present here data demonstrating that the mutation responsible for disease in the Brazilian kindred consists of two separate deletions (1,069 and 1,750 bp) surrounding and including exon 4. The deletion removing parkin exon 4 identified in the Turkish family extended 156,203 bp. In addition to demonstrating that disease in these families is not caused by a single founder mutation, these data show that there is no common fragile site between these mutational events.

  19. MOLECULAR ANALYSIS OF RADIATION-INDUCED MUTATION IN EXON 7/8 OF RAT HPRT GENE

    Institute of Scientific and Technical Information of China (English)

    任晓庆; 黄定九; 黄钢; 王利民

    2003-01-01

    Objective To investigate the relationship between the radiation dose and the HPRT gene locus mutation in rat smooth muscle cells, and provide the molecular basis for prevention of restenosis after percutaneous transluminal coronary angioplasty (PTCA).MethodsThe smooth muscle cells cultured in vitro were irradiated by radionuclide 188Re in different doses. HPRT gene mutation colonies were selected and isolated by 6 thioguanine. Analysis of mutation in exon 7/8 of HPRT gene were accomplished by polymerase chain reaction and single strand conformation polymorphism.ResultsThe HPRT gene mutation frequency of rat smooth muscle cells that were irradiated by radionuclide 188Re ranged from 5.5×10-6 to 13×10-6. Of 91 HPRT gene mutation colonies, 13(14.3%) contained exon 7/8 deletion and 15(16.5%) had point mutation. The exon 7/8 mutation frequency was 30.8%. There were significant relationships between radiation dose and mutation frequency of HPRT gene and exon 7/8.ConclusionThe DNA damage and gene mutation induced by radiation has positive relationship with radiation dose, and is a basis of proliferation inhibition and apoptosis of smooth muscle cells.

  20. Comprehensive survey of SNPs in the Affymetrix exon array using the 1000 Genomes dataset.

    Directory of Open Access Journals (Sweden)

    Eric R Gamazon

    Full Text Available Microarray gene expression data has been used in genome-wide association studies to allow researchers to study gene regulation as well as other complex phenotypes including disease risks and drug response. To reach scientifically sound conclusions from these studies, however, it is necessary to get reliable summarization of gene expression intensities. Among various factors that could affect expression profiling using a microarray platform, single nucleotide polymorphisms (SNPs in target mRNA may lead to reduced signal intensity measurements and result in spurious results. The recently released 1000 Genomes Project dataset provides an opportunity to evaluate the distribution of both known and novel SNPs in the International HapMap Project lymphoblastoid cell lines (LCLs. We mapped the 1000 Genomes Project genotypic data to the Affymetrix GeneChip Human Exon 1.0ST array (exon array, which had been used in our previous studies and for which gene expression data had been made publicly available. We also evaluated the potential impact of these SNPs on the differentially spliced probesets we had identified previously. Though the 1000 Genomes Project data allowed a comprehensive survey of the SNPs in this particular array, the same approach can certainly be applied to other microarray platforms. Furthermore, we present a detailed catalogue of SNP-containing probesets (exon-level and transcript clusters (gene-level, which can be considered in evaluating findings using the exon array as well as benefit the design of follow-up experiments and data re-analysis.

  1. Dual exon skipping in myostatin and dystrophin for Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    van Ommen Gert Jan B

    2011-04-01

    Full Text Available Abstract Background Myostatin is a potent muscle growth inhibitor that belongs to the Transforming Growth Factor-β (TGF-β family. Mutations leading to non functional myostatin have been associated with hypermuscularity in several organisms. By contrast, Duchenne muscular dystrophy (DMD is characterized by a loss of muscle fibers and impaired regeneration. In this study, we aim to knockdown myostatin by means of exon skipping, a technique which has been successfully applied to reframe the genetic defect of dystrophin gene in DMD patients. Methods We targeted myostatin exon 2 using antisense oligonucleotides (AON in healthy and DMD-derived myotubes cultures. We assessed the exon skipping level, transcriptional expression of myostatin and its target genes, and combined myostatin and several dystrophin AONs. These AONs were also applied in the mdx mice models via intramuscular injections. Results Myostatin AON induced exon 2 skipping in cell cultures and to a lower extent in the mdx mice. It was accompanied by decrease in myostatin mRNA and enhanced MYOG and MYF5 expression. Furthermore, combination of myostatin and dystrophin AONs induced simultaneous skipping of both genes. Conclusions We conclude that two AONs can be used to target two different genes, MSTN and DMD, in a straightforward manner. Targeting multiple ligands of TGF-beta family will be more promising as adjuvant therapies for DMD.

  2. Epidermal growth factor receptor exon 20 p.S768I mutation in non-small cell lung carcinoma

    DEFF Research Database (Denmark)

    Improta, Giuseppina; Pettinato, Angela; Gieri, Stefania;

    2016-01-01

    mutations may be used to identify tumors sensitive to the effects of small-molecule EGFR-TKIs (gefitinib and erlotinib), and alternative, less frequently observed mutations, including the majority of mutations identified within exon 20, may be associated with a lack of response to TKIs. However, due...... to the comparative rarity of EGFR exon 20 mutations, clinical information concerning the association between EGFR exon 20 mutations and responsiveness to TKIs has been limited within the relevant literature, particularly for certain rare mutations, including p.S768I. The current study reports the case of a patient...... with NSCLC harboring a p.S768I mutation in the EGFR gene [a substitution at codon 768 of exon 20 (c.2303G>T, p.S768I)], as well as a mutation at codon 719, exon 18 (p.G719A). The relevant literature concerning this rare EGFR somatic mutation is also reviewed....

  3. Identification of a novel mutation in hereditary vitamin D resistant rickets causing exon skipping.

    Science.gov (United States)

    Hawa, N S; Cockerill, F J; Vadher, S; Hewison, M; Rut, A R; Pike, J W; O'Riordan, J L; Farrow, S M

    1996-07-01

    Hereditary vitamin D resistant rickets (HVDRR) is an autosomal recessive disorder resulting in target organ resistance to the actions of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). In many cases, this disorder has been shown to be due to mutations in the gene encoding vitamin D receptors (VDR). In a patient with characteristic features of this disorder, we investigated the functional defect and sequenced the coding region of the gene for mutations. Skin fibroblasts from patient and control were used to measure binding of 1,25(OH)2D3 and functional responses to the hormone. These cells were also used to prepare RNA from which cDNA was prepared and sequenced. Furthermore, genomic DNA was prepared from the fibroblasts and the intron/exon boundaries sequenced. A child with classic features of HVDRR with alopecia diagnosed as having rickets due to resistance to 1,25(OH)2D3. Nuclear association of 1,25(OH)2D3 was determined in patient and control cells and the functional response to 1,25(OH)2D3 was assessed by measurement of 25-hydroxyvitamin D-24-hydroxylase(24-hydroxylase) activity. VDR cDNA and genomic DNA prepared from patient and control cells were sequenced. Cells from the patient with HVDRR had undetectable amounts of VDR compared to control cells and did not show induction of 24-hydroxylase activity following treatment with 1,25(OH)2D3. Sequencing of the VDR coding region after RT-PCR of RNA revealed an absence of exon 4 in patient RNA which was not due to a deletion in genomic DNA but was caused by exon skipping during RNA processing. In addition, the deletion of exon 4 sequences from RNA leads to a frameshift in translation resulting in a premature stop codon. Amplification of genomic DNA around the intron/exon boundary of exon 4 revealed a point mutation in the 5' donor splice site of intron 4. In this study, we have identified a novel mutation in the gene for vitamin D receptors in a patient with the characteristic phenotype of hereditary vitamin D resistant

  4. Folding Landscape of Mutant Huntingtin Exon1: Diffusible Multimers, Oligomers and Fibrils, and No Detectable Monomer.

    Directory of Open Access Journals (Sweden)

    Bankanidhi Sahoo

    Full Text Available Expansion of the polyglutamine (polyQ track of the Huntingtin (HTT protein above 36 is associated with a sharply enhanced risk of Huntington's disease (HD. Although there is general agreement that HTT toxicity resides primarily in N-terminal fragments such as the HTT exon1 protein, there is no consensus on the nature of the physical states of HTT exon1 that are induced by polyQ expansion, nor on which of these states might be responsible for toxicity. One hypothesis is that polyQ expansion induces an alternative, toxic conformation in the HTT exon1 monomer. Alternative hypotheses posit that the toxic species is one of several possible aggregated states. Defining the nature of the toxic species is particularly challenging because of facile interconversion between physical states as well as challenges to identifying these states, especially in vivo. Here we describe the use of fluorescence correlation spectroscopy (FCS to characterize the detailed time and repeat length dependent self-association of HTT exon1-like fragments both with chemically synthesized peptides in vitro and with cell-produced proteins in extracts and in living cells. We find that, in vitro, mutant HTT exon1 peptides engage in polyQ repeat length dependent dimer and tetramer formation, followed by time dependent formation of diffusible spherical and fibrillar oligomers and finally by larger, sedimentable amyloid fibrils. For expanded polyQ HTT exon1 expressed in PC12 cells, monomers are absent, with tetramers being the smallest molecular form detected, followed in the incubation time course by small, diffusible aggregates at 6-9 hours and larger, sedimentable aggregates that begin to build up at 12 hrs. In these cell cultures, significant nuclear DNA damage appears by 6 hours, followed at later times by caspase 3 induction, mitochondrial dysfunction, and cell death. Our data thus defines limits on the sizes and concentrations of different physical states of HTT exon1 along the

  5. Gene correction of a duchenne muscular dystrophy mutation by meganuclease-enhanced exon knock-in.

    Science.gov (United States)

    Popplewell, Linda; Koo, Taeyoung; Leclerc, Xavier; Duclert, Aymeric; Mamchaoui, Kamel; Gouble, Agnés; Mouly, Vincent; Voit, Thomas; Pâques, Frédéric; Cédrone, Frédéric; Isman, Olga; Yáñez-Muñoz, Rafael J; Dickson, George

    2013-07-01

    Duchenne muscular dystrophy (DMD) is a severe inherited, muscle-wasting disorder caused by mutations in the DMD gene. Gene therapy development for DMD has concentrated on vector-based DMD minigene transfer, cell-based gene therapy using genetically modified adult muscle stem cells or healthy wild-type donor cells, and antisense oligonucleotide-induced exon-skipping therapy to restore the reading frame of the mutated DMD gene. This study is an investigation into DMD gene targeting-mediated correction of deletions in human patient myoblasts using a target-specific meganuclease (MN) and a homologous recombination repair matrix. The MN was designed to cleave within DMD intron 44, upstream of a deletion hotspot, and integration-competent lentiviral vectors expressing the nuclease (LVcMN) were generated. MN western blotting and deep gene sequencing for LVcMN-induced non-homologous end-joining InDels (microdeletions or microinsertions) confirmed efficient MN expression and activity in transduced DMD myoblasts. A homologous repair matrix carrying exons 45-52 (RM45-52) was designed and packaged into integration-deficient lentiviral vectors (IDLVs; LVdRM45-52). After cotransduction of DMD myoblasts harboring a deletion of exons 45 to 52 with LVcMN and LVdRM45-52 vectors, targeted knock-in of the RM45-52 region in the correct location in DMD intron 44, and expression of full-length, correctly spliced wild-type dystrophin mRNA containing exons 45-52 were observed. This work demonstrates that genome surgery on human DMD gene mutations can be achieved by MN-induced locus-specific genome cleavage and homologous recombination knock-in of deleted exons. The feasibility of human DMD gene repair in patient myoblasts has exciting therapeutic potential.

  6. Short Tandem Repeats in Human Exons: A Target for Disease Mutations

    Directory of Open Access Journals (Sweden)

    Villesen Palle

    2008-09-01

    Full Text Available Abstract Background In recent years it has been demonstrated that structural variations, such as indels (insertions and deletions, are common throughout the genome, but the implications of structural variations are still not clearly understood. Long tandem repeats (e.g. microsatellites or simple repeats are known to be hypermutable (indel-rich, but are rare in exons and only occasionally associated with diseases. Here we focus on short (imperfect tandem repeats (STRs which fall below the radar of conventional tandem repeat detection, and investigate whether STRs are targets for disease-related mutations in human exons. In particular, we test whether they share the hypermutability of the longer tandem repeats and whether disease-related genes have a higher STR content than non-disease-related genes. Results We show that validated human indels are extremely common in STR regions compared to non-STR regions. In contrast to longer tandem repeats, our definition of STRs found them to be present in exons of most known human genes (92%, 99% of all STR sequences in exons are shorter than 33 base pairs and 62% of all STR sequences are imperfect repeats. We also demonstrate that STRs are significantly overrepresented in disease-related genes in both human and mouse. These results are preserved when we limit the analysis to STRs outside known longer tandem repeats. Conclusion Based on our findings we conclude that STRs represent hypermutable regions in the human genome that are linked to human disease. In addition, STRs constitute an obvious target when screening for rare mutations, because of the relatively low amount of STRs in exons (1,973,844 bp and the limited length of STR regions.

  7. Huntingtin exon 1 fibrils feature an interdigitated β-hairpin–based polyglutamine core

    Science.gov (United States)

    Hoop, Cody L.; Lin, Hsiang-Kai; Kar, Karunakar; Magyarfalvi, Gábor; Lamley, Jonathan M.; Boatz, Jennifer C.; Mandal, Abhishek; Lewandowski, Józef R.; Wetzel, Ronald

    2016-01-01

    Polyglutamine expansion within the exon1 of huntingtin leads to protein misfolding, aggregation, and cytotoxicity in Huntington’s disease. This incurable neurodegenerative disease is the most prevalent member of a family of CAG repeat expansion disorders. Although mature exon1 fibrils are viable candidates for the toxic species, their molecular structure and how they form have remained poorly understood. Using advanced magic angle spinning solid-state NMR, we directly probe the structure of the rigid core that is at the heart of huntingtin exon1 fibrils and other polyglutamine aggregates, via measurements of long-range intramolecular and intermolecular contacts, backbone and side-chain torsion angles, relaxation measurements, and calculations of chemical shifts. These experiments reveal the presence of β-hairpin–containing β-sheets that are connected through interdigitating extended side chains. Despite dramatic differences in aggregation behavior, huntingtin exon1 fibrils and other polyglutamine-based aggregates contain identical β-strand–based cores. Prior structural models, derived from X-ray fiber diffraction and computational analyses, are shown to be inconsistent with the solid-state NMR results. Internally, the polyglutamine amyloid fibrils are coassembled from differently structured monomers, which we describe as a type of “intrinsic” polymorphism. A stochastic polyglutamine-specific aggregation mechanism is introduced to explain this phenomenon. We show that the aggregation of mutant huntingtin exon1 proceeds via an intramolecular collapse of the expanded polyglutamine domain and discuss the implications of this observation for our understanding of its misfolding and aggregation mechanisms. PMID:26831073

  8. Alternatively Spliced Homologous Exons Have Ancient Origins and Are Highly Expressed at the Protein Level

    Science.gov (United States)

    Abascal, Federico; Ezkurdia, Iakes; Rodriguez-Rivas, Juan; Rodriguez, Jose Manuel; del Pozo, Angela; Vázquez, Jesús; Valencia, Alfonso; Tress, Michael L.

    2015-01-01

    Alternative splicing of messenger RNA can generate a wide variety of mature RNA transcripts, and these transcripts may produce protein isoforms with diverse cellular functions. While there is much supporting evidence for the expression of alternative transcripts, the same is not true for the alternatively spliced protein products. Large-scale mass spectroscopy experiments have identified evidence of alternative splicing at the protein level, but with conflicting results. Here we carried out a rigorous analysis of the peptide evidence from eight large-scale proteomics experiments to assess the scale of alternative splicing that is detectable by high-resolution mass spectroscopy. We find fewer splice events than would be expected: we identified peptides for almost 64% of human protein coding genes, but detected just 282 splice events. This data suggests that most genes have a single dominant isoform at the protein level. Many of the alternative isoforms that we could identify were only subtly different from the main splice isoform. Very few of the splice events identified at the protein level disrupted functional domains, in stark contrast to the two thirds of splice events annotated in the human genome that would lead to the loss or damage of functional domains. The most striking result was that more than 20% of the splice isoforms we identified were generated by substituting one homologous exon for another. This is significantly more than would be expected from the frequency of these events in the genome. These homologous exon substitution events were remarkably conserved—all the homologous exons we identified evolved over 460 million years ago—and eight of the fourteen tissue-specific splice isoforms we identified were generated from homologous exons. The combination of proteomics evidence, ancient origin and tissue-specific splicing indicates that isoforms generated from homologous exons may have important cellular roles. PMID:26061177

  9. Alternatively Spliced Homologous Exons Have Ancient Origins and Are Highly Expressed at the Protein Level.

    Directory of Open Access Journals (Sweden)

    Federico Abascal

    2015-06-01

    Full Text Available Alternative splicing of messenger RNA can generate a wide variety of mature RNA transcripts, and these transcripts may produce protein isoforms with diverse cellular functions. While there is much supporting evidence for the expression of alternative transcripts, the same is not true for the alternatively spliced protein products. Large-scale mass spectroscopy experiments have identified evidence of alternative splicing at the protein level, but with conflicting results. Here we carried out a rigorous analysis of the peptide evidence from eight large-scale proteomics experiments to assess the scale of alternative splicing that is detectable by high-resolution mass spectroscopy. We find fewer splice events than would be expected: we identified peptides for almost 64% of human protein coding genes, but detected just 282 splice events. This data suggests that most genes have a single dominant isoform at the protein level. Many of the alternative isoforms that we could identify were only subtly different from the main splice isoform. Very few of the splice events identified at the protein level disrupted functional domains, in stark contrast to the two thirds of splice events annotated in the human genome that would lead to the loss or damage of functional domains. The most striking result was that more than 20% of the splice isoforms we identified were generated by substituting one homologous exon for another. This is significantly more than would be expected from the frequency of these events in the genome. These homologous exon substitution events were remarkably conserved--all the homologous exons we identified evolved over 460 million years ago--and eight of the fourteen tissue-specific splice isoforms we identified were generated from homologous exons. The combination of proteomics evidence, ancient origin and tissue-specific splicing indicates that isoforms generated from homologous exons may have important cellular roles.

  10. TET2 exon 2 skipping is an independent favorable prognostic factor for cytogenetically normal acute myelogenous leukemia (AML): TET2 exon 2 skipping in AML.

    Science.gov (United States)

    Mohamed, Aminetou Mint; Balsat, Marie; Koering, Catherine; Maucort-Boulch, Delphine; Boissel, Nicolas; Payen-Gay, Lea; Cheok, Meyling; Mortada, Hussein; Auboeuf, Didier; Pinatel, Christiane; El-Hamri, Mohamed; Tigaud, Isabelle; Hayette, Sandrine; Dumontet, Charles; Cros, Emeline; Flandrin-Gresta, Pascale; Nibourel, Olivier; Preudhomme, Claude; Thomas, Xavier; Nicolini, Franck-Emmanuel; Solly, Françoise; Guyotat, Denis; Campos, Lydia; Michallet, Mauricette; Ceraulo, Antony; Mortreux, Franck; Wattel, Eric

    2017-01-16

    In AML, approximately one-third of expressed genes are abnormally spliced, including aberrant TET2 exon 2 expression. In a discovery cohort (n=99), TET2 exon 2 skipping (TET2E2S) was found positively associated with a significant reduction in the cumulative incidence of relapse (CIR). Age, cytogenetics, and TET2E2S were independent prognostic factors for disease-free survival (DFS), and favorable effects on outcomes predominated in cytogenetic normal (CN)-AML and younger patients. Using the same cutoff in a validation cohort of 86 CN-AML patients, TET2E2S(high) patients were found to be younger than TET2(low) patients without a difference in the rate of complete remission. However, TET2E2S(high) patients exhibited a significantly lower CIR (p<10(-4)). TET2E2S and FLT3-ITD, but not age or NPM1 mutation status were independent prognostic factors for DFS and event-free survival (EFS), while TET2E2S was the sole prognostic factor that we identified for overall survival (OS). In both the intermediate-1 and favorable ELN genetic categories, TET2E2S remained significantly associated with prolonged survival. There was no correlation between TET2E2S status and outcomes in 34 additional AML patients who were unfit for IC. Therefore our results suggest that assessments of TET2 exon 2 splicing status might improve risk stratification in CN-AML patients treated with IC.

  11. Risk Profiles and Penetrance Estimations in Multiple Endocrine Neoplasia Type 2A Caused by Germline RET Mutations Located in Exon 10

    NARCIS (Netherlands)

    Frank-Raue, Karin; Rybicki, Lisa A.; Erlic, Zoran; Schweizer, Heiko; Winter, Aurelia; Milos, Ioana; Toledo, Sergio P. A.; Toledo, Rodrigo A.; Tavares, Marcos R.; Alevizaki, Maria; Mian, Caterina; Siggelkow, Heide; Huefner, Michael; Wohllk, Nelson; Opocher, Giuseppe; Dvorakova, Sarka; Bendlova, Bela; Czetwertynska, Malgorzata; Skasko, Elzbieta; Barontini, Marta; Sanso, Gabriela; Vorlaender, Christian; Maia, Ana Luiza; Patocs, Attila; Links, Thera P.; de Groot, Jan Willem; Kerstens, Michiel N.; Valk, Gerlof D.; Miehle, Konstanze; Musholt, Thomas J.; Biarnes, Josefina; Damjanovic, Svetozar; Muresan, Mihaela; Wuester, Christian; Fassnacht, Martin; Peczkowska, Mariola; Fauth, Christine; Golcher, Henriette; Walter, Martin A.; Pichl, Josef; Raue, Friedhelm; Eng, Charis; Neumann, Hartmut P. H.

    2011-01-01

    Multiple endocrine neoplasia type 2 is characterized by germline mutations in RET. For exon 10, comprehensive molecular and corresponding phenotypic data are scarce. The International RET Exon 10 Consortium, comprising 27 centers from 15 countries, analyzed patients with RET exon 10 mutations for cl

  12. Delineation of the Marfan phenotype associated with mutations in exons 23-32 of the FBN1 gene

    Energy Technology Data Exchange (ETDEWEB)

    Putnam, E.A.; Cho, M.; Milewicz, D.M. [Univ. of Texas-Houston Medical School, Houston, TX (United States)] [and others

    1996-03-29

    Marfan syndrome is a dominantly inherited connective tissue disorder with a wide range of phenotypic severity. The condition is the result of mutations in FBN1, a large gene composed of 65 exons encoding the fibrillin-1 protein. While mutations causing classic manifestations of Marfan syndrome have been identified throughout the FBN1 gene, the six previously characterized mutations resulting in the severe, perinatal lethal form of Marfan syndrome have clustered in exons 24-32 of the gene. We screened 8 patients with either neonatal Marfan syndrome or severe cardiovascular complications of Marfan syndrome for mutations in this region of the gene. Using intron-based exon-specific primers, we amplified exons 23-32 from genomic DNAs, screened these fragments by single-stranded conformational polymorphism analysis, and sequenced indicated exons. This analysis documented mutations in exons 25-27 of the FBN1 mutations in 6 of these patients. These results, taken together with previously published FBN1 mutations in this region, further define the phenotype associated with mutations in exons 24-32 of the FBN1 gene, information important for the development of possible diagnostic tests and genetic counseling. 49 refs., 4 figs., 2 tabs.

  13. The role of germline promoters and I exons in cytokine-induced gene-specific class switch recombination.

    Science.gov (United States)

    Dunnick, Wesley A; Shi, Jian; Holden, Victoria; Fontaine, Clinton; Collins, John T

    2011-01-01

    Germline transcription precedes class switch recombination (CSR). The promoter regions and I exons of these germline transcripts include binding sites for activation- and cytokine-induced transcription factors, and the promoter regions/I exons are essential for CSR. Therefore, it is a strong hypothesis that the promoter/I exons regions are responsible for much of cytokine-regulated, gene-specific CSR. We tested this hypothesis by swapping the germline promoter and I exons for the murine γ1 and γ2a H chain genes in a transgene of the entire H chain C-region locus. We found that the promoter/I exon for γ1 germline transcripts can direct robust IL-4-induced recombination to the γ2a gene. In contrast, the promoter/I exon for the γ2a germline transcripts works poorly in the context of the γ1 H chain gene, resulting in expression of γ1 H chains that is type level. Nevertheless, the small amount of recombination to the chimeric γ1 gene is induced by IFN-γ. These results suggest that cytokine regulation of CSR, but not the magnitude of CSR, is regulated by the promoter/I exons.

  14. Translational regulation of human neuronal nitric-oxide synthase by an alternatively spliced 5'-untranslated region leader exon.

    Science.gov (United States)

    Newton, Derek C; Bevan, Sian C; Choi, Stephen; Robb, G Brett; Millar, Adam; Wang, Yang; Marsden, Philip A

    2003-01-03

    Expression of the neuronal nitric-oxide synthase (nNOS) mRNA is subject to complex cell-specific transcriptional regulation, which is mediated by alternative promoters. Unexpectedly, we identified a 89-nucleotide alternatively spliced exon located in the 5'-untranslated region between exon 1 variants and a common exon 2 that contains the translational initiation codon. Alternative splicing events that do not affect the open reading frame are distinctly uncommon in mammals; therefore, we assessed its functional relevance. Transient transfection of reporter RNAs performed in a variety of cell types revealed that this alternatively spliced exon acts as a potent translational repressor. Stably transfected cell lines confirmed that the alternatively spliced exon inhibited translation of the native nNOS open reading frame. Reverse transcription-PCR and RNase protection assays indicated that nNOS mRNAs containing this exon are common and expressed in both a promoter-specific and tissue-restricted fashion. Mutational analysis identified the functional cis-element within this novel exon, and a secondary structure prediction revealed that it forms a putative stem-loop. RNA electrophoretic mobility shift assay techniques revealed that a specific cytoplasmic RNA-binding complex interacts with this motif. Hence, a unique splicing event within a 5'-untranslated region is demonstrated to introduce a translational control element. This represents a newer model for the translational control of a mammalian mRNA.

  15. Effective exon skipping and dystrophin restoration by 2'-o-methoxyethyl antisense oligonucleotide in dystrophin-deficient mice.

    Directory of Open Access Journals (Sweden)

    Lu Yang

    Full Text Available Antisense oligonucleotide (AO-mediated exon-skipping therapy is one of the most promising therapeutic strategies for Duchenne Muscular Dystrophy (DMD and several AO chemistries have been rigorously investigated. In this report, we focused on the effect of 2'-O-methoxyethyl oligonucleotides (MOE on exon skipping in cultured mdx myoblasts and mice. Efficient dose-dependent skipping of targeted exon 23 was achieved in myoblasts with MOE AOs of different lengths and backbone chemistries. Furthermore, we established that 25-mer MOE phosphorothioate (PS AOs provided the greatest exon-skipping efficacy. When compared with 2'O methyl phosphorothioate (2'OmePS AOs, 25-mer MOE (PS AOs also showed higher exon-skipping activity in vitro and in mdx mice after intramuscular injections. Characterization of uptake in vitro corroborated with exon-skipping results, suggesting that increased uptake of 25-mer MOE PS AOs might partly contribute to the difference in exon-skipping activity observed in vitro and in mdx mice. Our findings demonstrate the substantial potential for MOE PS AOs as an alternative option for the treatment of DMD.

  16. 2′-O-Methyl RNA/Ethylene-Bridged Nucleic Acid Chimera Antisense Oligonucleotides to Induce Dystrophin Exon 45 Skipping

    Directory of Open Access Journals (Sweden)

    Tomoko Lee

    2017-02-01

    Full Text Available Duchenne muscular dystrophy (DMD is a fatal muscle-wasting disease characterized by dystrophin deficiency from mutations in the dystrophin gene. Antisense oligonucleotide (AO-mediated exon skipping targets restoration of the dystrophin reading frame to allow production of an internally deleted dystrophin protein with functional benefit for DMD patients who have out-of-frame deletions. After accelerated US approval of eteplirsen (Exondys 51, which targets dystrophin exon 51 for skipping, efforts are now focused on targeting other exons. For improved clinical benefits, this strategy requires more studies of the delivery method and modification of nucleic acids. We studied a nucleotide with a 2′-O,4′-C-ethylene-bridged nucleic acid (ENA, which shows high nuclease resistance and high affinity for complementary RNA strands. Here, we describe the process of developing a 2′-O-methyl RNA(2′-OMeRNA/ENA chimera AO to induce dystrophin exon 45 skipping. One 18-mer 2′-OMeRNA/ENA chimera (AO85 had the most potent activity for inducing exon 45 skipping in cultured myotubes. AO85 was administered to mdx mice without significant side effects. AO85 transfection into cultured myotubes from 13 DMD patients induced exon 45 skipping in all samples at different levels and dystrophin expression in 11 patients. These results suggest the possible efficacy of AO-mediated exon skipping changes in individual patients and highlight the 2′-OMeRNA/ENA chimera AO as a potential fundamental treatment for DMD.

  17. Identification of small molecule and genetic modulators of AON-induced dystrophin exon skipping by high-throughput screening.

    Directory of Open Access Journals (Sweden)

    Debra A O'Leary

    Full Text Available One therapeutic approach to Duchenne Muscular Dystrophy (DMD recently entering clinical trials aims to convert DMD phenotypes to that of a milder disease variant, Becker Muscular Dystrophy (BMD, by employing antisense oligonucleotides (AONs targeting splice sites, to induce exon skipping and restore partial dystrophin function. In order to search for small molecule and genetic modulators of AON-dependent and independent exon skipping, we screened approximately 10,000 known small molecule drugs, >17,000 cDNA clones, and >2,000 kinase- targeted siRNAs against a 5.6 kb luciferase minigene construct, encompassing exon 71 to exon 73 of human dystrophin. As a result, we identified several enhancers of exon skipping, acting on both the reporter construct as well as endogenous dystrophin in mdx cells. Multiple mechanisms of action were identified, including histone deacetylase inhibition, tubulin modulation and pre-mRNA processing. Among others, the nucleolar protein NOL8 and staufen RNA binding protein homolog 2 (Stau2 were found to induce endogenous exon skipping in mdx cells in an AON-dependent fashion. An unexpected but recurrent theme observed in our screening efforts was the apparent link between the inhibition of cell cycle progression and the induction of exon skipping.

  18. Molecular effects of autoimmune-risk promoter polymorphisms on expression, exon choice, and translational efficiency of interferon regulatory factor 5.

    Science.gov (United States)

    Clark, Daniel N; Lambert, Jared P; Till, Rodney E; Argueta, Lissenya B; Greenhalgh, Kathryn E; Henrie, Brandon; Bills, Trieste; Hawkley, Tyson F; Roznik, Marinya G; Sloan, Jason M; Mayhew, Vera; Woodland, Loc; Nelson, Eric P; Tsai, Meng-Hsuan; Poole, Brian D

    2014-05-01

    The rs2004640 single nucleotide polymorphism and the CGGGG copy-number variant (rs77571059) are promoter polymorphisms within interferon regulatory factor 5 (IRF5). They have been implicated as susceptibility factors for several autoimmune diseases. IRF5 uses alternative promoter splicing, where any of 4 first exons begin the mRNA. The CGGGG indel is in exon 1A's promoter; the rs2004640 allele creates a splicing recognition site, enabling usage of exon 1B. This study aimed at characterizing alterations in IRF5 mRNA due to these polymorphisms. Cells with risk polymorphisms exhibited ~2-fold higher levels of IRF5 mRNA and protein, but demonstrated no change in mRNA stability. Quantitative PCR demonstrated decreased usage of exons 1C and 1D in cell lines with the risk polymorphisms. RNA folding analysis revealed a hairpin in exon 1B; mutational analysis showed that the hairpin shape decreased translation 5-fold. Although translation of mRNA that uses exon 1B is low due to a hairpin, increased IRF5 mRNA levels in individuals with the rs2004640 risk allele lead to higher overall protein expression. In addition, several new splice variants of IRF5 were sequenced. IRF5's promoter polymorphisms alter first exon usage and increase transcription levels. High levels of IRF5 may bias the immune system toward autoimmunity.

  19. Alternative splicing and differential gene expression in colon cancer detected by a whole genome exon array

    Directory of Open Access Journals (Sweden)

    Sugnet Charles

    2006-12-01

    Full Text Available Abstract Background Alternative splicing is a mechanism for increasing protein diversity by excluding or including exons during post-transcriptional processing. Alternatively spliced proteins are particularly relevant in oncology since they may contribute to the etiology of cancer, provide selective drug targets, or serve as a marker set for cancer diagnosis. While conventional identification of splice variants generally targets individual genes, we present here a new exon-centric array (GeneChip Human Exon 1.0 ST that allows genome-wide identification of differential splice variation, and concurrently provides a flexible and inclusive analysis of gene expression. Results We analyzed 20 paired tumor-normal colon cancer samples using a microarray designed to detect over one million putative exons that can be virtually assembled into potential gene-level transcripts according to various levels of prior supporting evidence. Analysis of high confidence (empirically supported transcripts identified 160 differentially expressed genes, with 42 genes occupying a network impacting cell proliferation and another twenty nine genes with unknown functions. A more speculative analysis, including transcripts based solely on computational prediction, produced another 160 differentially expressed genes, three-fourths of which have no previous annotation. We also present a comparison of gene signal estimations from the Exon 1.0 ST and the U133 Plus 2.0 arrays. Novel splicing events were predicted by experimental algorithms that compare the relative contribution of each exon to the cognate transcript intensity in each tissue. The resulting candidate splice variants were validated with RT-PCR. We found nine genes that were differentially spliced between colon tumors and normal colon tissues, several of which have not been previously implicated in cancer. Top scoring candidates from our analysis were also found to substantially overlap with EST-based bioinformatic

  20. Deletion and Mutation of WWOX Exons 6-8 in Human Non-small Cell Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To examine the deletion and point mutation of WWOX (WW domain containing oxidoreductase) exons 6-8 in human non-small cell lung cancer and their possible relationship with pathological stages, tumor tissues and the corresponding normal tissues were obtained from 44 Chinese patients who had undergone surgery for non-small cell lung cancer. RNA was extracted from each sample and deletion and mutation of WWOX exons 6-8 were analyzed by RT-PCR and DNA sequencing. Our results showed that 28 of 44 (63.6 %) lung cancer samples showed loss of WWOX exons 6-8 transcript and the deletion was detected in only 3 of 44 (6.8 %) corresponding adjacent normal tissues (P<0.05). The transcript sequencing analyses of the 16 lung cancer samples without transcript loss of WWOX exons 6-8 revealed no difference from the sequence of GenBank. Moreover, the deletion of WWOX exons 6-8 was significantly higher in the smokers when compared with the non-smokers. It is also higher in the men and squamous carcinomas than in women and adenocarcinomas (P<0.05). The deletion, however, was not found to be associated with pathological stages of the tumors. Our study documented a high incidence of deletion of WWOX exons 6-8 in non-small cell lung cancer in Chinese patients and suggested that the frequent loss of WWOX exons 6-8 might play an important role in the tumorigenesis of non-small cell lung cancer in Chinese. WWOX exons 6-8 may serves as a candidate molecular target of smoking carcinogenesis, and point mutation is not a predominant way of alteration of WWOX exons 6-8.

  1. Functional Analysis of Mutations in Exon 9 of NF1 Reveals the Presence of Several Elements Regulating Splicing.

    Directory of Open Access Journals (Sweden)

    Elisabete Hernández-Imaz

    Full Text Available Neurofibromatosis type 1 (NF1 is one of the most common human hereditary disorders, predisposing individuals to the development of benign and malignant tumors in the nervous system, as well as other clinical manifestations. NF1 is caused by heterozygous mutations in the NF1 gene and around 25% of the pathogenic changes affect pre-mRNA splicing. Since the molecular mechanisms affected by these mutations are poorly understood, we have analyzed the splicing mutations identified in exon 9 of NF1, which is particularly prone to such changes, to better define the possible splicing regulatory elements. Using a minigene approach, we studied the effect of five splicing mutations in this exon described in patients. These highlighted three regulatory motifs within the exon. An in vivo splicing analysis of an extensive collection of changes generated in the minigene demonstrated that the CG motif at c.910-911 is critical for the recognition of exon 9. We also found that the GC motif at c.945-946 is involved in exon recognition through SRSF2 and that this motif is part of a Composite Exon Splicing Regulatory Element made up of physically overlapping enhancer and silencer elements. Finally, through an in vivo splicing analysis and in vitro binding assays, we demonstrated that the c.1007G>A mutation creates an Exonic Splicing Silencer element that binds the hnRNPA1 protein. The complexity of the splicing regulatory elements present in exon 9 is most likely responsible for the fact that mutations in this region represent 25% of all exonic changes that affect splicing in the NF1 gene.

  2. CD86嵌合抗体对系统性红斑狼疮患者自身反应性B细胞的作用及影响研究%Effects of an anti-CD86 chimeric antibody (ch1D1) on autoreactive B lymphocytes isolated from pa-tients with SLE

    Institute of Scientific and Technical Information of China (English)

    刘玉华; 陈兆军; 韩杰; 潘峰; 鄢巨振; 张腊红; 郑小银; 刘杨

    2016-01-01

    目的:探讨CD86嵌合抗体ch1D1对系统性红斑狼疮( systemic lupus erythematosus, SLE)患者自身反应性B细胞的作用及影响。方法利用流式细胞术分析SLE患者B细胞表面CD86的表达水平及ch1D1对SLE患者CD4+T细胞活化的影响;利用磁珠法分选出健康志愿者和SLE患者外周血单个核细胞( PBMC)中的B细胞、NK细胞以及CD4+T细胞用于后续实验;利用LDH释放法检测ch1D1介导对SLE患者B细胞的抗体依赖的细胞介导的细胞毒作用( antibody dependent cell medi-ated cytotoxicity,ADCC)及补体依赖的细胞介导的细胞毒作用( complement dependent cell mediated cy-totoxicity,CDC),利用ELISA法检测ch1D1对SLE患者B细胞分泌自身抗体的影响,利用3H掺入法分析ch1D1对SLE患者CD4+T细胞增殖的影响。结果 SLE患者B细胞上CD80(68.08±14.28 vs 46.10±12.14,n=24,P<0.0001)和CD86(44.72±14.90 vs 13.99±10.74,n=24,P<0.0001)的表达水平显著高于健康志愿者,提示B细胞异常活化;与对照组相比,ch1D1能更有效介导对SLE患者B细胞的ADCC和CDC作用(P=0.0172,P=0.0388);活化的T细胞显著增强SLE患者B细胞产生自身抗体,ch1D1显著抑制了SLE患者自身抗体的分泌(P=0.0019);SLE患者CD4+T细胞活化和增殖水平显著高于健康志愿者,而ch1D1显著抑制 SLE患者 CD4+T细胞的增殖和活化( P=0.0024,P=0.0495)。结论 CD86嵌合抗体能更有效地介导对SLE患者自身反应性B细胞的ADCC和CDC作用,抑制其自身抗体的分泌,抑制自身反应性CD4+T细胞的增殖和活化,有望成为治疗SLE的新型免疫制剂。%Objective To investigate the effects of ch1D1, an anti-CD86 chimeric antibody, on autoreactive B lymphocytes isolated from patients with systemic lupus erythematosus ( SLE) . Methods Flow cytometry analysis was performed to measure the expression of CD86 on the surface of B cells isolated from patients with SLE and to analyze the effects of ch1D1 on the activation of CD4+T cells

  3. BRCA1 Exon 11, a CERES (Composite Regulatory Element of Splicing Element Involved in Splice Regulation

    Directory of Open Access Journals (Sweden)

    Claudia Tammaro

    2014-07-01

    Full Text Available Unclassified variants (UV of BRCA1 can affect normal pre-mRNA splicing. Here, we investigate the UV c.693G>A, a “silent” change in BRCA1 exon 11, which we have found induces aberrant splicing in patient carriers and in vitro. Using a minigene assay, we show that the UV c.693G>A has a strong effect on the splicing isoform ratio of BRCA1. Systematic site-directed mutagenesis of the area surrounding the nucleotide position c.693G>A induced variable changes in the level of exon 11 inclusion/exclusion in the mRNA, pointing to the presence of a complex regulatory element with overlapping enhancer and silencer functions. Accordingly, protein binding analysis in the region detected several splicing regulatory factors involved, including SRSF1, SRSF6 and SRSF9, suggesting that this sequence represents a composite regulatory element of splicing (CERES.

  4. LACKING EXON5 OF VARIANT ESTROGEN RECEPTOR IN HUMAN BREAST CANCER

    Institute of Scientific and Technical Information of China (English)

    Zhang Lei; Gong Ping; Sun Sulian; Dong Zhiwei

    1998-01-01

    Methods: The target sequence of ER RNA covering exon4~6(1082~1520bp) was amplified in 7 clinical human breast cancer tissues by reverse transcription and polymerase chain reaction (RT-PCR) techniques.Results: PCR products were transferred to nitrocellulose membranes and hybridized using a [r-32P]-ATP labeled ER 29 oligonulceotide probe representing the antisense strand of the ER Cdna sequence 1271~1299. Specific bands were found at 438 and 300 base pairs in two tumors. The 300 base pair of PCR product was recovered from ER+/PR+ and ER+/PR- tumor, respectively.Conclusion: Dideoxy sequence analysis revealed that they contained the variant ER completely missing exon 5.

  5. Exons 16 and 17 of the amyloid precursor protein gene in familial inclusion body myopathy.

    Science.gov (United States)

    Sivakumar, K; Cervenáková, L; Dalakas, M C; Leon-Monzon, M; Isaacson, S H; Nagle, J W; Vasconcelos, O; Goldfarb, L G

    1995-08-01

    Accumulation of beta-amyloid protein (A beta) occurs in some muscle fibers of patients with inclusion body myopathy and resembles the type of amyloid deposits seen in the affected tissues of patients with Alzheimer's disease and cerebrovascular amyloidosis. Because mutations in exons 16 and 17 of the beta-amyloid precursor protein (beta APP) gene on chromosome 21 have been identified in patients with early-onset familial Alzheimer's disease and Dutch-type cerebrovascular amyloidosis, we searched for mutations of the same region in patients with familial inclusion body myopathy. Sequencing of both alleles in 8 patients from four unrelated families did not reveal any mutations in these exons. The amyloid deposition in familial forms of inclusion body myopathy may be either due to errors in other gene loci, or it is secondary reflecting altered beta APP metabolism or myocyte degeneration and cell membrane degradation.

  6. Alternative splicing in colon, bladder, and prostate cancer identified by exon-array analysis

    DEFF Research Database (Denmark)

    Thorsen, Kasper; Sørensen, Karina D.; Brems-Eskildsen, Anne Sofie;

    2008-01-01

    Alternative splicing enhances proteome diversity and modulates cancer-associated proteins. To identify tissue- and tumor-specific alternative splicing, we used the GeneChip Human Exon 1.0 ST Array to measure whole-genome exon expression in 102 normal and cancer tissue samples of different stages......, and 18 candidate tumor-specific splicing alterations in colon, bladder, and prostate, respectively, were selected for RT-PCR validation on an independent set of 81 normal and tumor tissue samples. In total, seven genes with tumor-specific splice variants were identified (ACTN1, CALD1, COL6A3, LRRFIP2...... from colon, urinary bladder, and prostate. We identified 2069 candidate alternative splicing events between normal tissue samples from colon, bladder, and prostate and selected 15 splicing events for RT-PCR validation, 10 of which were successfully validated by RT-PCR and sequencing. Furthermore 23, 19...

  7. Screening of BRCA1 sequence variants within exon 11 by heteroduplex analysis

    Directory of Open Access Journals (Sweden)

    Lucian Negura

    2013-03-01

    Full Text Available Germ-line mutations of either BRCA1 or BRCA2 represents the major hereditary risk to breast and ovariancancer. Screening for mutations in these genes is now standard practice in molecular diagnosis, opening the way tooncogenetic counselling and follow-up. Because mutations in both BRCA1 and BRCA2 are distributed throughout theloci, accepted clinical protocols involve screening their entire coding regions. Systematic Sanger sequencing is time andmoney consuming. Therefore, a lot of pre-screening techniques evolved over time in order to identify anomalousamplicons prior to sequencing. Because BRCA mutations are always heterozygous, heteroduplex analysis proved to be asuitable pre-screening step. We previously implemented mismatch specific endonuclease heteroduplex analysis forBRCA1 exon7. Here we show the utility of the same method for mutations and SNPs found in BRCA1 exon 11

  8. Transcriptional enhancers in protein-coding exons of vertebrate developmental genes.

    Directory of Open Access Journals (Sweden)

    Deborah I Ritter

    Full Text Available Many conserved noncoding sequences function as transcriptional enhancers that regulate gene expression. Here, we report that protein-coding DNA also frequently contains enhancers functioning at the transcriptional level. We tested the enhancer activity of 31 protein-coding exons, which we chose based on strong sequence conservation between zebrafish and human, and occurrence in developmental genes, using a Tol2 transposable GFP reporter assay in zebrafish. For each exon we measured GFP expression in hundreds of embryos in 10 anatomies via a novel system that implements the voice-recognition capabilities of a cellular phone. We find that 24/31 (77% exons drive GFP expression compared to a minimal promoter control, and 14/24 are anatomy-specific (expression in four anatomies or less. GFP expression driven by these coding enhancers frequently overlaps the anatomies where the host gene is expressed (60%, suggesting self-regulation. Highly conserved coding sequences and highly conserved noncoding sequences do not significantly differ in enhancer activity (coding: 24/31 vs. noncoding: 105/147 or tissue-specificity (coding: 14/24 vs. noncoding: 50/105. Furthermore, coding and noncoding enhancers display similar levels of the enhancer-related histone modification H3K4me1 (coding: 9/24 vs noncoding: 34/81. Meanwhile, coding enhancers are over three times as likely to contain an H3K4me1 mark as other exons of the host gene. Our work suggests that developmental transcriptional enhancers do not discriminate between coding and noncoding DNA and reveals widespread dual functions in protein-coding DNA.

  9. Selective Blockade of Periostin Exon 17 Preserves Cardiac Performance in Acute Myocardial Infarction.

    Science.gov (United States)

    Taniyama, Yoshiaki; Katsuragi, Naruto; Sanada, Fumihiro; Azuma, Junya; Iekushi, Kazuma; Koibuchi, Nobutaka; Okayama, Keita; Ikeda-Iwabu, Yuka; Muratsu, Jun; Otsu, Rei; Rakugi, Hiromi; Morishita, Ryuichi

    2016-02-01

    We previously reported that overexpression of full-length periostin, Pn-1, resulted in ventricular dilation with enhanced interstitial collagen deposition in a rat model. However, other reports have documented that the short-form splice variants Pn-2 (lacking exon 17) and Pn-4 (lacking exons 17 and 21) promoted cardiac repair by angiogenesis and prevented cardiac rupture after acute myocardial infarction. The apparently differing findings from those reports prompted us to use a neutralizing antibody to selectively inhibit Pn-1 by blockade of exon 17 in a rat acute myocardial infarction model. Administration of Pn neutralizing antibody resulted in a significant decrease in the infarcted and fibrotic areas of the myocardium, which prevented ventricular wall thinning and dilatation. The inhibition of fibrosis by Pn neutralizing antibody was associated with a significant decrease in gene expression of fibrotic markers, including collagen I, collagen III, and transforming growth factor-β1. Importantly, the number of α-smooth muscle actin-positive myofibroblasts was significantly reduced in the hearts of animals treated with Pn neutralizing antibody, whereas cardiomyocyte proliferation and angiogenesis were comparable in the IgG and neutralizing antibody groups. Moreover, the level of Pn-1 expression was significantly correlated with the severity of myocardial infarction. In addition, Pn-1, but not Pn-2 or Pn-4, inhibited fibroblast and myocyte attachment, which might account for the cell slippage observed during cardiac remodeling. Collectively, these results indicate that therapeutics that specifically inhibit Pn exon-17, via a neutralizing antibody or drug, without suppressing other periostin variants might offer a new class of medication for the treatment of acute myocardial infarction patients.

  10. MET exon 14 juxtamembrane splicing mutations: clinical and therapeutical perspectives for cancer therapy

    Science.gov (United States)

    Pilotto, Sara; Gkountakos, Anastasios; Carbognin, Luisa; Scarpa, Aldo; Tortora, Giampaolo

    2017-01-01

    The MET proto-oncogene plays crucial roles in cell growth and proliferation, survival and apoptosis, epithelial-mesenchymal transition (EMT) and invasion, potentially conditioning the development and progression of the carcinogenesis process. The MET-associated aberrant signaling could be triggered by a variety of mechanisms, such as mutations, gene amplification, increased gene copy number and Met/HGF protein expression. Among the various MET alterations, MET exon 14 splicing abnormalities, causing the loss of the Met juxtamembrane (JM) domain, recently emerged as a new potential oncogenic driver and have been identified and validated across different cancer and histology subtypes. Moreover, this aberration was found to be mutually exclusive with other recognized drivers, thus strongly nominating its potential oncogenic role. Recently, the clinical activity of anti-Met-targeted therapy was demonstrated particularly in patients harboring MET exon 14 skipping lung cancer, resulting in a renewed enthusiasm to further test MET precision therapy in prospective trials. In this review, the key preclinical and clinical data regarding MET exon 14 skipping splicing variants as an actionable genomic aberration in cancer are described, and the perspectives deriving from the validation of such alteration as a potential target, which may further allow driving the therapeutic approach in this molecularly selected patients’ subgroup, are explored. PMID:28164087

  11. Gene identification using exon amplification on human chromosome 18q21: implications for bipolar disorder.

    Science.gov (United States)

    Chen, H; Huo, Y; Patel, S; Zhu, X; Swift-Scanlan, T; Reeves, R H; DePaulo, R; Ross, C A; McInnis, M G

    2000-09-01

    We previously reported linkage between bipolar disorder and a region on human chromosome (HC) 18q21. To identify genes in this region, exon trapping was performed on cosmids isolated from an HC18-specific cosmid library (LL18NC02) using 47 sequence tagged site (STS) markers from 18q21 as hybridization probes. A total of 285 unique sequences (exons) were obtained from 850 sequenced clones. Homology searching of the databases using NCBI's BLAST algorithms revealed that 31 exons have identity to known genes and/or ESTs, seven are identical to regions of finished genomic sequences in the 18q21 region, 20 have significant similarity (>30% sequence identity) to genes from human and/or other species, 19 were repetitive sequences, and 208 sequences (72%) are novel. Seventy per cent of the trapped sequences were predicted to be derived from genes using library screening and RT-PCR analyses. This represents an initial stage in characterizing genes in a susceptibility region for further study in bipolar disorder or other diseases that map to this region.

  12. First Report of a Single Exon Deletion in TCOF1 Causing Treacher Collins Syndrome.

    Science.gov (United States)

    Beygo, J; Buiting, K; Seland, S; Lüdecke, H-J; Hehr, U; Lich, C; Prager, B; Lohmann, D R; Wieczorek, D

    2012-01-01

    Treacher Collins syndrome (TCS) is a rare craniofacial disorder characterized by facial anomalies and ear defects. TCS is caused by mutations in the TCOF1 gene and follows autosomal dominant inheritance. Recently, mutations in the POLR1D and POLR1C genes have also been identified to cause TCS. However, in a subset of patients no causative mutation could be found yet. Inter- and intrafamilial phenotypic variability is high as is the variety of mainly family-specific mutations identified throughout TCOF1. No obvious correlation between pheno- and genotype could be observed. The majority of described point mutations, small insertions and deletions comprising only a few nucleotides within TCOF1 lead to a premature termination codon. We investigated a cohort of 112 patients with a tentative clinical diagnosis of TCS by multiplex ligation-dependent probe amplification (MLPA) to search for larger deletions not detectable with other methods used. All patients were selected after negative screening for mutations in TCOF1, POLR1D and POLR1C. In 1 patient with an unequivocal clinical diagnosis of TCS, we identified a 3.367 kb deletion. This deletion abolishes exon 3 and is the first described single exon deletion within TCOF1. On RNA level we observed loss of this exon which supposedly leads to haploinsufficiency of TREACLE, the nucleolar phosphoprotein encoded by TCOF1.

  13. MET exon 14 juxtamembrane splicing mutations: clinical and therapeutical perspectives for cancer therapy.

    Science.gov (United States)

    Pilotto, Sara; Gkountakos, Anastasios; Carbognin, Luisa; Scarpa, Aldo; Tortora, Giampaolo; Bria, Emilio

    2017-01-01

    The MET proto-oncogene plays crucial roles in cell growth and proliferation, survival and apoptosis, epithelial-mesenchymal transition (EMT) and invasion, potentially conditioning the development and progression of the carcinogenesis process. The MET-associated aberrant signaling could be triggered by a variety of mechanisms, such as mutations, gene amplification, increased gene copy number and Met/HGF protein expression. Among the various MET alterations, MET exon 14 splicing abnormalities, causing the loss of the Met juxtamembrane (JM) domain, recently emerged as a new potential oncogenic driver and have been identified and validated across different cancer and histology subtypes. Moreover, this aberration was found to be mutually exclusive with other recognized drivers, thus strongly nominating its potential oncogenic role. Recently, the clinical activity of anti-Met-targeted therapy was demonstrated particularly in patients harboring MET exon 14 skipping lung cancer, resulting in a renewed enthusiasm to further test MET precision therapy in prospective trials. In this review, the key preclinical and clinical data regarding MET exon 14 skipping splicing variants as an actionable genomic aberration in cancer are described, and the perspectives deriving from the validation of such alteration as a potential target, which may further allow driving the therapeutic approach in this molecularly selected patients' subgroup, are explored.

  14. Vyhledávání exonů pomocí Fourierovy transformace

    OpenAIRE

    Rusina, Michal

    2013-01-01

    V této bakalářské práci jsou popsány metody predikce exonů. První část práce je zaměřena na rozdíl mezi prokaryotickými a eukaryotickými organismy, popis struktury DNA a vysvětlení pojmů exon a intron. Druhý úsek teoretické části obsahuje čtyři metody predikce exonů a to dynamické programování, neuronové sítě, skryté Markovovy modely a diskrétní Fourierovu transformaci. V praktické části byl vytvořen program Predikce_exonu, který vyhledává exony v nukleotidových sekvencích a pracuje na princi...

  15. Detection of c-kit gene mutations in Exon 11 of Leukemias

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    Syed Rizwan Hussain

    2012-03-01

    Full Text Available OBJECTIVE: To identify mutations in c-kit gene in exon 11 in Leukemia cases. METHODS: In order to determine the frequency of mutations of Exon 11 of c-kit gene in 50 Leukemia cases (31 samples Acute Myeloid Leukemia, 5 samples Acute Lymphoblastic Leukemia, 9 samples Chronic Myeloid Leukemia and 5 samples Chronic Lymphocytic Leukemia, we have done PCR-SSCP followed by direct DNA sequencing. RESULTS: Of 50 Leukemia cases, 28 were male and 22 were female with ages ranging from 2 to 65 years. The mean age of cases was 31.88 years. We have detected total twenty mutations in nineteen cases that include Lys550Asn, Tyr568Ser, Ile571Thr, Thr574Pro, Gln575His, Tyr578Pro, Asp579His, His580Gln, Arg586Thr, Asn587Asp and Arg588Met as well as novel point mutations at codons Ile563Lys, Val569Leu, Tyr570Ser, and Pro577Ser. Ile571Leu substitution is found in two independent cases whereas Trp582Ser substitution is found in three individual cases. CONCLUSION: These observations suggest that mutations in exon 11 of the c-kit gene might represent useful molecular genetic markers in Leukemia.

  16. Performance of genotype imputation for rare variants identified in exons and flanking regions of genes.

    Directory of Open Access Journals (Sweden)

    Li Li

    Full Text Available Genotype imputation has the potential to assess human genetic variation at a lower cost than assaying the variants using laboratory techniques. The performance of imputation for rare variants has not been comprehensively studied. We utilized 8865 human samples with high depth resequencing data for the exons and flanking regions of 202 genes and Genome-Wide Association Study (GWAS data to characterize the performance of genotype imputation for rare variants. We evaluated reference sets ranging from 100 to 3713 subjects for imputing into samples typed for the Affymetrix (500K and 6.0 and Illumina 550K GWAS panels. The proportion of variants that could be well imputed (true r(2>0.7 with a reference panel of 3713 individuals was: 31% (Illumina 550K or 25% (Affymetrix 500K with MAF (Minor Allele Frequency less than or equal 0.001, 48% or 35% with 0.0010.05. The performance for common SNPs (MAF>0.05 within exons and flanking regions is comparable to imputation of more uniformly distributed SNPs. The performance for rare SNPs (0.01exon resequencing into additional samples with GWAS data, but imputation of very rare variants (MAF< = 0.005 will require reference panels with thousands of subjects.

  17. Alternative Splicing of a Novel Inducible Exon Diversifies the CASK Guanylate Kinase Domain

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    Jill A. Dembowski

    2012-01-01

    Full Text Available Alternative pre-mRNA splicing has a major impact on cellular functions and development with the potential to fine-tune cellular localization, posttranslational modification, interaction properties, and expression levels of cognate proteins. The plasticity of regulation sets the stage for cells to adjust the relative levels of spliced mRNA isoforms in response to stress or stimulation. As part of an exon profiling analysis of mouse cortical neurons stimulated with high KCl to induce membrane depolarization, we detected a previously unrecognized exon (E24a of the CASK gene, which encodes for a conserved peptide insertion in the guanylate kinase interaction domain. Comparative sequence analysis shows that E24a appeared selectively in mammalian CASK genes as part of a >3,000 base pair intron insertion. We demonstrate that a combination of a naturally defective 5 splice site and negative regulation by several splicing factors, including SC35 (SRSF2 and ASF/SF2 (SRSF1, drives E24a skipping in most cell types. However, this negative regulation is countered with an observed increase in E24a inclusion after neuronal stimulation and NMDA receptor signaling. Taken together, E24a is typically a skipped exon, which awakens during neuronal stimulation with the potential to diversify the protein interaction properties of the CASK polypeptide.

  18. Suppression of 5' splice-sites through multiple exonic motifs by hnRNP L.

    Science.gov (United States)

    Loh, Tiing Jen; Choi, Namjeong; Moon, Heegyum; Jang, Ha Na; Liu, Yongchao; Zhou, Jianhua; Zheng, Xuexiu; Shen, Haihong

    2017-03-01

    Selection of 5' splice-sites (5'SS) in alternative splicing plays an important role in gene regulation. Although regulatory mechanisms of heterogeneous nuclear ribonucleoprotein L (hnRNP L), a well-known splicing regulatory protein, have been studied in a substantial level, its role in 5'SS selection is not thoroughly defined. By using a KLF6 pre-mRNA alternative splicing model, we demonstrate in this report that hnRNP L inhibits proximal 5'SS but promotes two consecutive distal 5'SS splicing, antagonizing SRSF1 roles in KLF6 pre-mRNA splicing. In addition, three consecutive CA-rich sequences in a CA cassette immediately upstream of the proximal 5'SS are all required for hnRNP L functions. Importantly, the CA-cassette locations on the proximal exon do not affect hnRNP L roles. We further show that the proximal 5'SS but not the two distal 5'SSs are essential for hnRNP L activities. Notably, in a Bcl-x pre-mRNA model that contains two alternative 5'SS but includes CA-rich elements at distal exon, we demonstrate that hnRNP L also suppresses nearby 5'SS activation. Taken together, we conclude that hnRNP L suppresses 5'SS selection through multiple exonic motifs.

  19. Mini-Exon Genotyping of Leishmania Species in Khuzestan Province, Southwest Iran

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    E Razmjou

    2010-02-01

    Full Text Available "nBackground: Leishmaniasis is a protozoan disease cause by Leishmania genus. Anthroponotic and zoono­tic cutaneous leishmaniasis are endemic in Iran. The aim of this study was to identify the causative agent of cutaneous leishmaniasis by mini-exon gene in five regions of Khuzestan Province, southwest of Iran."nMethods: From 2007 to 2008 in this cross-sectional study, cutaneous samples were collected from patients referred to Health Centers and Hospitals of the Khuzestan Province for cutaneous leishmaniasis diagnosis and cultured in Novy-MacNeal-Nicolle (NNN and RPMI 1640. The propagated promastigotes were harvested and Leishmania species of cutaneous leishmaniasis were identified by RFLP and DNA sequencing of the PCR generated fragments."nResults: L. major and L. tropica were the causative agents of cutaneous leishmaniasis by predomi­nantly of L. major species. The alignment of the mini-exon sequencing isolates with re­ported sequencing of L. major and L. tropica revealed 92%-99% identity."nConclusion: Our study showed that mini-exon PCR-RFLP was useful method to identify the causa­tive species of cutaneous leishmaniasis.

  20. Exon loss accounts for differential sorting of Na-K-Cl cotransporters in polarized epithelial cells.

    Science.gov (United States)

    Carmosino, Monica; Giménez, Ignacio; Caplan, Michael; Forbush, Biff

    2008-10-01

    The renal Na-K-Cl cotransporter (NKCC2) is selectively expressed in the apical membranes of cells of the mammalian kidney, where it is the target of the clinically important loop diuretics. In contrast, the "secretory" NKCC1 cotransporter is localized in the basolateral membranes of many epithelia. To identify the sorting signal(s) that direct trafficking of NKCCs, we generated chimeras between the two isoforms and expressed these constructs in polarized renal epithelial cell lines. This analysis revealed an amino acid stretch in NKCC2 containing apical sorting information. The NKCC1 C terminus contains a dileucine motif that constitutes the smallest essential component of its basolateral sorting signal. NKCC1 lacking this motif behaves as an apical protein. Examination of the NKCC gene structure reveals that this dileucine motif is encoded by an additional exon in NKCC1 absent in NKCC2. Phylogenetic analysis of this exon suggests that the evolutionary loss of this exon from the gene encoding the basolateral NKCC1 constitutes a novel mechanism that accounts for the apical sorting of the protein encoded by the NKCC2 gene.

  1. Detection of clinically relevant exonic copy-number changes by array CGH.

    Science.gov (United States)

    Boone, Philip M; Bacino, Carlos A; Shaw, Chad A; Eng, Patricia A; Hixson, Patricia M; Pursley, Amber N; Kang, Sung-Hae L; Yang, Yaping; Wiszniewska, Joanna; Nowakowska, Beata A; del Gaudio, Daniela; Xia, Zhilian; Simpson-Patel, Gayle; Immken, LaDonna L; Gibson, James B; Tsai, Anne C-H; Bowers, Jennifer A; Reimschisel, Tyler E; Schaaf, Christian P; Potocki, Lorraine; Scaglia, Fernando; Gambin, Tomasz; Sykulski, Maciej; Bartnik, Magdalena; Derwinska, Katarzyna; Wisniowiecka-Kowalnik, Barbara; Lalani, Seema R; Probst, Frank J; Bi, Weimin; Beaudet, Arthur L; Patel, Ankita; Lupski, James R; Cheung, Sau Wai; Stankiewicz, Pawel

    2010-12-01

    Array comparative genomic hybridization (aCGH) is a powerful tool for the molecular elucidation and diagnosis of disorders resulting from genomic copy-number variation (CNV). However, intragenic deletions or duplications--those including genomic intervals of a size smaller than a gene--have remained beyond the detection limit of most clinical aCGH analyses. Increasing array probe number improves genomic resolution, although higher cost may limit implementation, and enhanced detection of benign CNV can confound clinical interpretation. We designed an array with exonic coverage of selected disease and candidate genes and used it clinically to identify losses or gains throughout the genome involving at least one exon and as small as several hundred base pairs in size. In some patients, the detected copy-number change occurs within a gene known to be causative of the observed clinical phenotype, demonstrating the ability of this array to detect clinically relevant CNVs with subkilobase resolution. In summary, we demonstrate the utility of a custom-designed, exon-targeted oligonucleotide array to detect intragenic copy-number changes in patients with various clinical phenotypes.

  2. Chemical and mechanistic toxicology evaluation of exon skipping phosphorodiamidate morpholino oligomers in mdx mice.

    Science.gov (United States)

    Sazani, Peter; Ness, Kirk P Van; Weller, Doreen L; Poage, Duane; Nelson, Keith; Shrewsbury, And Stephen B

    2011-05-01

    AVI-4658 is a phosphorodiamidate morpholino oligomer (PMO) designed to induce skipping of dystrophin exon 51 and restore its expression in patients with Duchenne muscular dystrophy (DMD). Preclinically, restoration of dystrophin in the dystrophic mdx mouse model requires skipping of exon 23, achieved with the mouse-specific PMO, AVI-4225. Herein, we report the potential toxicological consequences of exon skipping and dystrophin restoration in mdx mice using AVI-4225. We also evaluated the toxicological effects of AVI-4658 in both mdx and wild-type mice. In both studies, animals were dosed once weekly for 12 weeks up to the maximum feasible dose of 960 mg/kg per injection. Both AVI-4658 and AVI-4225 were well-tolerated at all doses. Findings in AVI-4225-treated animals were generally limited to mild renal tubular basophilia/vacuolation, without any significant changes in renal function and with evidence of reversing. No toxicity associated with the mechanism of action of AVI-4225 in a dystrophic animal was observed.

  3. Characterization of Exon 2 and Intron 2 of Leptin Gene in Native Anatolian Goat Breeds

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    Özge BAKIRCIOĞLU

    2016-07-01

    Full Text Available Studies performed on farm animals like cattle and pig have shown that there has been a relationship between leptin gene (LEP and carcass meat quality, milk production and content, and economic parameters such as reproduction and food consumption. There has been scarce research conducted related to leptin gene of sheep and especially goat. The aim of the study is to reveal the genetic structures of goats living in Turkey through nucleotide sequence analysis in targeted zones of LEP gene Exon 2 and Intron 2 of Anatolian Black, Kilis and Angora goat breeds which are commonly fed in Anatolia. According to the sequence analysis results of each three breeds, Anatolian Black goat breed have the highest haplotype number with nucleotide and haplotype diversity both in exon 2 and intron 2. There was only one haplotype found in both exon 2 and intron 2 in Angora goat breed. There was no nucleotide diversity found in individuals belonging to Angora goat breed. Taking the regions analyzed for LEP gene into consideration, it is seen that Anatolian Black goat breed has the highest genetic diversity among other goat breeds fed in Anatolia. Future studies upon the LEP gene in goats should take into account of increasing the sample size and of base in order to obtain more useful information for better understanding the gene structure.

  4. Fine Structure Constant, Domain Walls, and Generalized Uncertainty Principle in the Universe

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    Luigi Tedesco

    2011-01-01

    Full Text Available We study the corrections to the fine structure constant from the generalized uncertainty principle in the spacetime of a domain wall. We also calculate the corrections to the standard formula to the energy of the electron in the hydrogen atom to the ground state, in the case of spacetime of a domain wall and generalized uncertainty principle. The results generalize the cases known in literature.

  5. Exon organization of the mouse entactin gene corresponds to the structural domains of the polypeptide and has regional homology to the low-density lipoprotein receptor gene

    DEFF Research Database (Denmark)

    Durkin, M E; Wewer, U M; Chung, A E

    1995-01-01

    Entactin is a widespread basement membrane protein of 150 kDa that binds to type IV collagen and laminin. The complete exon-intron structure of the mouse entactin gene has been determined from lambda genomic DNA clones. The gene spans at least 65 kb and contains 20 exons. The exon organization...... of the mouse entactin gene closely corresponds to the organization of the polypeptide into distinct structural and functional domains. The two amino-terminal globular domains are encoded by three exons each. Single exons encode the two protease-sensitive, O-glycosylated linking regions. The six EGF......-like repeats and the single thyroglobulin-type repeat are each encoded by separate exons. The carboxyl-terminal half of entactin displays sequence homology to the growth factor-like region of the low-density lipoprotein receptor, and in both genes this region is encoded by eight exons. The positions of four...

  6. Acetylcholinesterase (AChE) gene modification in transgenic animals: functional consequences of selected exon and regulatory region deletion.

    Science.gov (United States)

    Camp, Shelley; Zhang, Limin; Marquez, Michael; de la Torre, Brian; Long, Jeffery M; Bucht, Goran; Taylor, Palmer

    2005-12-15

    AChE is an alternatively spliced gene. Exons 2, 3 and 4 are invariantly spliced, and this sequence is responsible for catalytic function. The 3' alternatively spliced exons, 5 and 6, are responsible for AChE disposition in tissue [J. Massoulie, The origin of the molecular diversity and functional anchoring of cholinesterases. Neurosignals 11 (3) (2002) 130-143; Y. Li, S. Camp, P. Taylor, Tissue-specific expression and alternative mRNA processing of the mammalian acetylcholinesterase gene. J. Biol. Chem. 268 (8) (1993) 5790-5797]. The splice to exon 5 produces the GPI anchored form of AChE found in the hematopoietic system, whereas the splice to exon 6 produces a sequence that binds to the structural subunits PRiMA and ColQ, producing AChE expression in brain and muscle. A third alternative RNA species is present that is not spliced at the 3' end; the intron 3' of exon 4 is used as coding sequence and produces the read-through, unanchored form of AChE. In order to further understand the role of alternative splicing in the expression of the AChE gene, we have used homologous recombination in stem cells to produce gene specific deletions in mice. Alternatively and together exon 5 and exon 6 were deleted. A cassette containing the neomycin gene flanked by loxP sites was used to replace the exon(s) of interest. Tissue analysis of mice with exon 5 deleted and the neomycin cassette retained showed very low levels of AChE expression, far less than would have been anticipated. Only the read-through species of the enzyme was produced; clearly the inclusion of the selection cassette disrupted splicing of exon 4 to exon 6. The selection cassette was then deleted in exon 5, exon 6 and exons 5 + 6 deleted mice by breeding to Ella-cre transgenic mice. AChE expression in serum, brain and muscle has been analyzed. Another AChE gene targeted mouse strain involving a region in the first intron, found to be critical for AChE expression in muscle cells [S. Camp, L. Zhang, M. Marquez, B

  7. Exon Deletion Pattern in Duchene Muscular Dystrophy in North West of Iran

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    Mohammad BARZEGAR

    2015-01-01

    Full Text Available How to Cite This Article: Barzegar M, Habibi P, Bonyady M, Topchizadeh V, Shiva Sh. Exon Deletion Pattern in Duchene Muscular Dystrophy in North West of Iran. Iran J Child Neurol. 2015 Winter; 9(1: 42-48.AbstractObjectiveDuchene and Becker Muscular Dystrophy (DMD/ BMD are x-linked disorders that both are the result of heterogeneous mutations in the dystrophin gene. The frequency and distribution of dystrophin gene deletions in DMD/ BMD patients show different patterns among different populations. This study investigates the deletion rate, type, and distribution of this gene in the Azeri Turk population of North West Iran.Materials &MethodsIn this study, 110 patients with DMD/ BMD were studied for intragenic deletions in 24 exons and promoter regions of dystrophin genes by using multiplex PCR.ResultsDeletions were detected in 63 (57.3% patients, and around 83% localized in the mid-distal hotspot of the gene (on exons 44–52, 21 cases (33.3 % with singleexon deletions, and 42 cases (66.6% with multi-exonic deletions. The most frequent deleted exons were exon 50 (15 % and exon 49 (14%. No deletion was detected in exon 3.ConclusionThis study suggests that the frequency and pattern of dystrophin gene deletions in DMD/ BMD in the Azeri Turk population of North West Iran occur in the same pattern when compared with other ethnic groups.ReferencesEmery AE. Clinical and molecular studies in Duchenne muscular dystrophy. Prog Clin Biol Res 1989; 306:15-28.Moser H. Duchenne muscular dystrophy: pathogenic aspects and genetic prevention. Hum Genet 1984; 66(1:17-40.Emery AE. Population Frequencies of inherited neuromuscular diseases: a world survey Neuromuscul Disord 1991; I (I:19-29.Bushby KM, Thmabyayah M, Gardner M D. Prevalence and incidence of Becker muscular dystrophy. Lancet 1991; 337(8748:1022-1024.Koenig M, Hoffman EP, Bertelosn CJ, Monaco AP, Feener C, Kunkel LM. Complete cloning of the Duchenne muscular dystrophy (DMD DNA and

  8. Deleting exon 55 from the nebulin gene induces severe muscle weakness in a mouse model for nemaline myopathy

    OpenAIRE

    Ottenheijm, Coen A. C.; Buck, Danielle; de Winter, Josine M; Ferrara, Claudia; Piroddi, Nicoletta; Tesi, Chiara; Jasper, Jeffrey R.; Malik, Fady I.; Meng, Hui; Stienen, Ger J. M.; Beggs, Alan H.; Labeit, Siegfried; Poggesi, Corrado; Lawlor, Michael W.; Granzier, Henk

    2013-01-01

    Nebulin—a giant sarcomeric protein—plays a pivotal role in skeletal muscle contractility by specifying thin filament length and function. Although mutations in the gene encoding nebulin (NEB) are a frequent cause of nemaline myopathy, the most common non-dystrophic congenital myopathy, the mechanisms by which mutations in NEB cause muscle weakness remain largely unknown. To better understand these mechanisms, we have generated a mouse model in which Neb exon 55 is deleted (NebΔExon55) to repl...

  9. Novel Exons and Splice Variants in the Human Antibody Heavy Chain Identified by Single Cell and Single Molecule Sequencing

    Science.gov (United States)

    Vollmers, Christopher; Penland, Lolita; Kanbar, Jad N.; Quake, Stephen R.

    2015-01-01

    Antibody heavy chains contain a variable and a constant region. The constant region of the antibody heavy chain is encoded by multiple groups of exons which define the isotype and therefore many functional characteristics of the antibody. We performed both single B cell RNAseq and long read single molecule sequencing of antibody heavy chain transcripts and were able to identify novel exons for IGHA1 and IGHA2 as well as novel isoforms for IGHM antibody heavy chain. PMID:25611855

  10. Novel exons and splice variants in the human antibody heavy chain identified by single cell and single molecule sequencing.

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    Christopher Vollmers

    Full Text Available Antibody heavy chains contain a variable and a constant region. The constant region of the antibody heavy chain is encoded by multiple groups of exons which define the isotype and therefore many functional characteristics of the antibody. We performed both single B cell RNAseq and long read single molecule sequencing of antibody heavy chain transcripts and were able to identify novel exons for IGHA1 and IGHA2 as well as novel isoforms for IGHM antibody heavy chain.

  11. Polymorphisms of the ICAM-1 exon 6 (E469K) are associated with differentiation of colorectal cancer

    OpenAIRE

    Wen Jin-Kun; Han Yi; Liu Yue-Ping; Miao Sui-Bing; Liu Ya-bin; Liu Bin; Li Bing-hui; Wang Qing-lei; Han Mei

    2009-01-01

    Abstract Background Genetic factors are thought to play a role in development for colorectal carcinogenesis. ICAM-1 is a polymorphic gene, thus, the present study investigated the relationship between the polymorphisms of ICAM-1 and the susceptibility and phenotypical characteristics of colorectal cancer (CRC). Methods The polymorphisms at ICAM-1 exon 4 (G241R) and exon 6 (E469K) were detected by PCR with sequence-specific primers. The relationship between specific genotypes of ICAM-1 and dif...

  12. Wild-type mouse models to screen antisense oligonucleotides for exon-skipping efficacy in Duchenne muscular dystrophy.

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    Limin Cao

    Full Text Available A readily available animal model is essential for rapidly identifying effective treatments for Duchenne muscular dystrophy (DMD, a devastating neuromuscular disorder caused by the lack of dystrophin protein, which results from frame-disrupting mutations in the DMD gene. Currently, the mdx mouse is the most commonly used model for antisense oligonucleotide (AO-mediated exon skipping pre-clinical studies, with a mild phenotype. However, the accessibility of mdx mouse colonies particularly in developing countries can constrain research. Therefore in this study we explore the feasibility of using wild-type mice as models to establish exon-skipping efficiency of various DMD AO chemistries and their conjugates. Four different strains of wild-type mice and six different AO chemistries were investigated intramuscularly and the results indicated that the same exon-skipping efficiency was achieved for all tested AOs as that from mdx mice. Notably, levels of exon-skipping obtained in C57BL6 and C3H and mdx mice were most closely matched, followed by ICR and BALB/C mice. Systemic validation revealed that wild-type mice are less responsive to AO-mediated exon skipping than mdx mice. Our study provides evidence for the first time that wild-type mice can be appropriate models for assessing DMD AO exon-skipping efficiency with similar sensitivity to that of mdx mice and this finding can further accelerate the development of effective DMD AOs.

  13. A novel break point of the BMPR2 gene exonic deletion in a patient with pulmonary arterial hypertension.

    Science.gov (United States)

    Aimi, Yuki; Hirayama, Tomomi; Kataoka, Masaharu; Momose, Yuichi; Nishimaki, Saiko; Matsushita, Kenichi; Yoshino, Hideaki; Satoh, Toru; Gamou, Shinobu

    2013-12-01

    The presence of genetic rearrangements of bone morphogenetic protein type 2 receptor (BMPR2) was identified in pulmonary arterial hypertension (PAH) patients as the deletion or duplication of one or more exons of the gene. We recently investigated the deletion break points in exonic deletions of BMPR2 in two Japanese familial cases with PAH, and found that these were Alu-mediated via either non-allelic homologous recombination or non-homologous recombination. We herein report the third case of exonic deletion, which was in a 25-year-old female PAH patient with a deletion of BMPR2 exon 3. The break point in this case was not located in an Alu sequence. The 5'- and 3'-break point maps between the inverted Alu sequences in intron 2 and in exon 3, respectively, resulted in a 759-bp deletion. This novel exonic deletion in this PAH case may be a unique and non-recurrent rearrangement, and appears to be of a different size from that in other patients.

  14. Identification and evolutionary analysis of novel exons and alternative splicing events using cross-species EST-to-genome comparisons in human, mouse and rat

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    Ho Jar-Yi

    2006-03-01

    Full Text Available Abstract Background Alternative splicing (AS is important for evolution and major biological functions in complex organisms. However, the extent of AS in mammals other than human and mouse is largely unknown, making it difficult to study AS evolution in mammals and its biomedical implications. Results Here we describe a cross-species EST-to-genome comparison algorithm (ENACE that can identify novel exons for EST-scanty species and distinguish conserved and lineage-specific exons. The identified exons represent not only novel exons but also evolutionarily meaningful AS events that are not previously annotated. A genome-wide AS analysis in human, mouse and rat using ENACE reveals a total of 758 novel cassette-on exons and 167 novel retained introns that have no EST evidence from the same species. RT-PCR-sequencing experiments validated ~50 ~80% of the tested exons, indicating high presence of exons predicted by ENACE. ENACE is particularly powerful when applied to closely related species. In addition, our analysis shows that the ENACE-identified AS exons tend not to pass the nonsynonymous-to-synonymous substitution ratio test and not to contain protein domain, implying that such exons may be under positive selection or relaxed negative selection. These AS exons may contribute to considerable inter-species functional divergence. Our analysis further indicates that a large number of exons may have been gained or lost during mammalian evolution. Moreover, a functional analysis shows that inter-species divergence of AS events may be substantial in protein carriers and receptor proteins in mammals. These exons may be of interest to studies of AS evolution. The ENACE programs and sequences of the ENACE-identified AS events are available for download. Conclusion ENACE can identify potential novel cassette exons and retained introns between closely related species using a comparative approach. It can also provide information regarding lineage- or species

  15. Exon sequence requirements for excision in vivo of the bacterial group II intron RmInt1

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    Toro Nicolás

    2011-05-01

    Full Text Available Abstract Background Group II intron splicing proceeds through two sequential transesterification reactions in which the 5' and 3'-exons are joined together and the lariat intron is released. The intron-encoded protein (IEP assists the splicing of the intron in vivo and remains bound to the excised intron lariat RNA in a ribonucleoprotein particle (RNP that promotes intron mobility. Exon recognition occurs through base-pairing interactions between two guide sequences on the ribozyme domain dI known as EBS1 and EBS2 and two stretches of sequence known as IBS1 and IBS2 on the 5' exon, whereas the 3' exon is recognized through interaction with the sequence immediately upstream from EBS1 [(δ-δ' interaction (subgroup IIA] or with a nucleotide [(EBS3-IBS3 interaction (subgroup IIB and IIC] located in the coordination-loop of dI. The δ nucleotide is involved in base pairing with another intron residue (δ' in subgroup IIB introns and this interaction facilitates base pairing between the 5' exon and the intron. Results In this study, we investigated nucleotide requirements in the distal 5'- and 3' exon regions, EBS-IBS interactions and δ-δ' pairing for excision of the group IIB intron RmInt1 in vivo. We found that the EBS1-IBS1 interaction was required and sufficient for RmInt1 excision. In addition, we provide evidence for the occurrence of canonical δ-δ' pairing and its importance for the intron excision in vivo. Conclusions The excision in vivo of the RmInt1 intron is a favored process, with very few constraints for sequence recognition in both the 5' and 3'-exons. Our results contribute to understand how group II introns spread in nature, and might facilitate the use of RmInt1 in gene targeting.

  16. Deleting exon 55 from the nebulin gene induces severe muscle weakness in a mouse model for nemaline myopathy.

    Science.gov (United States)

    Ottenheijm, Coen A C; Buck, Danielle; de Winter, Josine M; Ferrara, Claudia; Piroddi, Nicoletta; Tesi, Chiara; Jasper, Jeffrey R; Malik, Fady I; Meng, Hui; Stienen, Ger J M; Beggs, Alan H; Labeit, Siegfried; Poggesi, Corrado; Lawlor, Michael W; Granzier, Henk

    2013-06-01

    Nebulin--a giant sarcomeric protein--plays a pivotal role in skeletal muscle contractility by specifying thin filament length and function. Although mutations in the gene encoding nebulin (NEB) are a frequent cause of nemaline myopathy, the most common non-dystrophic congenital myopathy, the mechanisms by which mutations in NEB cause muscle weakness remain largely unknown. To better understand these mechanisms, we have generated a mouse model in which Neb exon 55 is deleted (Neb(ΔExon55)) to replicate a founder mutation seen frequently in patients with nemaline myopathy with Ashkenazi Jewish heritage. Neb(ΔExon55) mice are born close to Mendelian ratios, but show growth retardation after birth. Electron microscopy studies show nemaline bodies--a hallmark feature of nemaline myopathy--in muscle fibres from Neb(ΔExon55) mice. Western blotting studies with nebulin-specific antibodies reveal reduced nebulin levels in muscle from Neb(ΔExon55) mice, and immunofluorescence confocal microscopy studies with tropomodulin antibodies and phalloidin reveal that thin filament length is significantly reduced. In line with reduced thin filament length, the maximal force generating capacity of permeabilized muscle fibres and single myofibrils is reduced in Neb(ΔExon55) mice with a more pronounced reduction at longer sarcomere lengths. Finally, in Neb(ΔExon55) mice the regulation of contraction is impaired, as evidenced by marked changes in crossbridge cycling kinetics and by a reduction of the calcium sensitivity of force generation. A novel drug that facilitates calcium binding to the thin filament significantly augmented the calcium sensitivity of submaximal force to levels that exceed those observed in untreated control muscle. In conclusion, we have characterized the first nebulin-based nemaline myopathy model, which recapitulates important features of the phenotype observed in patients harbouring this particular mutation, and which has severe muscle weakness caused by

  17. Accelerated exchange of exon segments in Viperid three-finger toxin genes (Sistrurus catenatus edwardsii; Desert Massasauga

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    Mackessy Stephen P

    2008-07-01

    Full Text Available Abstract Background Snake venoms consist primarily of proteins and peptides showing a myriad of potent biological activities which have been shaped by both adaptive and neutral selective forces. Venom proteins are encoded by multigene families that have evolved through a process of gene duplication followed by accelerated evolution in the protein coding region. Results Here we report five gene structures of three-finger toxins from a viperid snake, Sistrurus catenatus edwardsii. These toxin genes are structured similarly to elapid and hydrophiid three-finger toxin genes, with two introns and three exons. Both introns and exons show distinct patterns of segmentation, and the insertion/deletion of segments may define their evolutionary history. The segments in introns, when present, are highly similar to their corresponding segments in other members of the gene family. In contrast, some segments in the exons show high similarity, while others are often distinctly different among corresponding regions of the isoforms. Conclusion Ordered, conserved exon structure strongly suggests that segments in corresponding regions in exons have been exchanged with distinctly different ones during the evolution of these genes. Such a "switching" of segments in exons may result in drastically altering the molecular surface topology and charge, and hence the molecular targets of these three-finger toxins. Thus the phenomenon of accelerated segment switch in exons to alter targeting (ASSET may play an important role in the evolution of three-finger toxins, resulting in a family of toxins with a highly conserved structural fold but widely varying biological activities.

  18. Context Dependent Effects of Chimeric Peptide Morpholino Conjugates Contribute to Dystrophin Exon-skipping Efficiency

    Directory of Open Access Journals (Sweden)

    HaiFang Yin

    2013-01-01

    Full Text Available We have recently reported that cell-penetrating peptides (CPPs and novel chimeric peptides containing CPP (referred as B peptide and muscle-targeting peptide (referred as MSP motifs significantly improve the systemic exon-skipping activity of morpholino phosphorodiamidate oligomers (PMOs in dystrophin-deficient mdx mice. In the present study, the general mechanistic significance of the chimeric peptide configuration on the activity and tissue uptake of peptide conjugated PMOs in vivo was investigated. Four additional chimeric peptide-PMO conjugates including newly identified peptide 9 (B-9-PMO and 9-B-PMO and control peptide 3 (B-3-PMO and 3-B-PMO were tested in mdx mice. Immunohistochemical staining, RT-PCR and western blot results indicated that B-9-PMO induced significantly higher level of exon skipping and dystrophin restoration than its counterpart (9-B-PMO, further corroborating the notion that the activity of chimeric peptide-PMO conjugates is dependent on relative position of the tissue-targeting peptide motif within the chimeric peptide with respect to PMOs. Subsequent mechanistic studies showed that enhanced cellular uptake of B-MSP-PMO into muscle cells leads to increased exon-skipping activity in comparison with MSP-B-PMO. Surprisingly, further evidence showed that the uptake of chimeric peptide-PMO conjugates of both orientations (B-MSP-PMO and MSP-B-PMO was ATP- and temperature-dependent and also partially mediated by heparan sulfate proteoglycans (HSPG, indicating that endocytosis is likely the main uptake pathway for both chimeric peptide-PMO conjugates. Collectively, our data demonstrate that peptide orientation in chimeric peptides is an important parameter that determines cellular uptake and activity when conjugated directly to oligonucleotides. These observations provide insight into the design of improved cell targeting compounds for future therapeutics studies.

  19. Context Dependent Effects of Chimeric Peptide Morpholino Conjugates Contribute to Dystrophin Exon-skipping Efficiency.

    Science.gov (United States)

    Yin, Haifang; Boisguerin, Prisca; Moulton, Hong M; Betts, Corinne; Seow, Yiqi; Boutilier, Jordan; Wang, Qingsong; Walsh, Anthony; Lebleu, Bernard; Wood, Matthew Ja

    2013-09-24

    We have recently reported that cell-penetrating peptides (CPPs) and novel chimeric peptides containing CPP (referred as B peptide) and muscle-targeting peptide (referred as MSP) motifs significantly improve the systemic exon-skipping activity of morpholino phosphorodiamidate oligomers (PMOs) in dystrophin-deficient mdx mice. In the present study, the general mechanistic significance of the chimeric peptide configuration on the activity and tissue uptake of peptide conjugated PMOs in vivo was investigated. Four additional chimeric peptide-PMO conjugates including newly identified peptide 9 (B-9-PMO and 9-B-PMO) and control peptide 3 (B-3-PMO and 3-B-PMO) were tested in mdx mice. Immunohistochemical staining, RT-PCR and western blot results indicated that B-9-PMO induced significantly higher level of exon skipping and dystrophin restoration than its counterpart (9-B-PMO), further corroborating the notion that the activity of chimeric peptide-PMO conjugates is dependent on relative position of the tissue-targeting peptide motif within the chimeric peptide with respect to PMOs. Subsequent mechanistic studies showed that enhanced cellular uptake of B-MSP-PMO into muscle cells leads to increased exon-skipping activity in comparison with MSP-B-PMO. Surprisingly, further evidence showed that the uptake of chimeric peptide-PMO conjugates of both orientations (B-MSP-PMO and MSP-B-PMO) was ATP- and temperature-dependent and also partially mediated by heparan sulfate proteoglycans (HSPG), indicating that endocytosis is likely the main uptake pathway for both chimeric peptide-PMO conjugates. Collectively, our data demonstrate that peptide orientation in chimeric peptides is an important parameter that determines cellular uptake and activity when conjugated directly to oligonucleotides. These observations provide insight into the design of improved cell targeting compounds for future therapeutics studies.Molecular Therapy-Nucleic Acids (2013) 2, e124; doi:10.1038/mtna.2013

  20. Normal phenotype in conditional androgen receptor (AR) exon 3-floxed neomycin-negative male mice.

    Science.gov (United States)

    Rana, Kesha; Clarke, Michele V; Zajac, Jeffrey D; Davey, Rachel A; MacLean, Helen E

    2014-01-01

    Androgens (testosterone and dihydrotestosterone) acting via the androgen receptor (AR) are required for male sexual differentiation, and also regulate the development of many other tissues including muscle, fat and bone. We previously generated an AR(lox) mouse line with exon 3 of the AR gene targeted by loxP sites. The deletion of exon 3 is in-frame, so only the DNA binding-dependent actions of the AR are deleted, but non-DNA binding-dependent actions are retained. This line also contained an antibiotic resistance selection cassette, neomycin (neo) in intron 3, which was also flanked by loxP sites. Hemizygous AR(lox) male mice demonstrated a phenotype of hyperandrogenization, with increased mass of androgen-dependent tissues. We hypothesized that this hyperandrogenization was likely to be due to the presence of the neo cassette. In this study, we have generated an AR(lox) neo-negative mouse line, using the EIIa-cre deleter mouse line to remove the neo cassette. Hemizygous AR(lox) neo-negative male mice have a normal phenotype, with normal body mass and normal mass of androgen-dependent tissues including the testis, seminal vesicles, kidney, spleen, heart and retroperitoneal fat. This neo-negative exon 3-targeted mouse line is the only floxed AR mouse line available to study the DNA binding-dependent actions of the AR in a tissue-specific manner, and is suitable for investigation in all tissues. This study demonstrates the importance of removing the selection cassette, which can potentially alter the phenotype of floxed mouse lines even in the absence of detectable effects on target gene expression.

  1. Mutation Scanning in Wheat by Exon Capture and Next-Generation Sequencing.

    Directory of Open Access Journals (Sweden)

    Robert King

    Full Text Available Targeted Induced Local Lesions in Genomes (TILLING is a reverse genetics approach to identify novel sequence variation in genomes, with the aims of investigating gene function and/or developing useful alleles for breeding. Despite recent advances in wheat genomics, most current TILLING methods are low to medium in throughput, being based on PCR amplification of the target genes. We performed a pilot-scale evaluation of TILLING in wheat by next-generation sequencing through exon capture. An oligonucleotide-based enrichment array covering ~2 Mbp of wheat coding sequence was used to carry out exon capture and sequencing on three mutagenised lines of wheat containing previously-identified mutations in the TaGA20ox1 homoeologous genes. After testing different mapping algorithms and settings, candidate SNPs were identified by mapping to the IWGSC wheat Chromosome Survey Sequences. Where sequence data for all three homoeologues were found in the reference, mutant calls were unambiguous; however, where the reference lacked one or two of the homoeologues, captured reads from these genes were mis-mapped to other homoeologues, resulting either in dilution of the variant allele frequency or assignment of mutations to the wrong homoeologue. Competitive PCR assays were used to validate the putative SNPs and estimate cut-off levels for SNP filtering. At least 464 high-confidence SNPs were detected across the three mutagenized lines, including the three known alleles in TaGA20ox1, indicating a mutation rate of ~35 SNPs per Mb, similar to that estimated by PCR-based TILLING. This demonstrates the feasibility of using exon capture for genome re-sequencing as a method of mutation detection in polyploid wheat, but accurate mutation calling will require an improved genomic reference with more comprehensive coverage of homoeologues.

  2. Sequences and polymorphisms of exons 3 and 4 in porcine UCP2 gene

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Uncoupling proteins are mitochondrial membrane transporters, which regulate metabolic pathways of energy balance, and are associated with biological traits of animal body weight, resting metabolic rates and energy conversion. In this study, a region of the exons 3 and 4 of pig UCP2 gene was cloned and analyzed, and a new single nucleotide polymorphic site was detected by PCR-SSCP in five pig breeds. This newfound polymorphism results from a T to G substitution at the position of nucleotide 272, which is located in intron3.

  3. A Multi-Agent System for Exon Prediction in Human Sequences.

    Science.gov (United States)

    Vignal; Lisacek

    1997-01-01

    Given the problem of identifying exons in new genomic DNA, the sketch of a resolution process was drawn using sequence data and models of site/signal recognition. A multi-agent architecture is used to validate these models and test hypotheses on the chronology of events involved in gene splicing. Information is channelled through a hierarchy of agents. Each type of agent is the result of a successful step in the resolution process. The system does not rely on the compositional bias of coding sequences which is a key feature of current computer methods.

  4. Becker muscular dystrophy with widespread muscle hypertrophy and a non-sense mutation of exon 2

    DEFF Research Database (Denmark)

    Witting, Nanna; Duno, M; Vissing, J

    2013-01-01

    Becker muscular dystrophy features progressive proximal weakness, wasting and often focal hypertrophy. We present a patient with pain and cramps from adolescence. Widespread muscle hypertrophy, preserved muscle strength and a 10-20-fold raised CPK were noted. Muscle biopsy was dystrophic......, and Western blot showed a 95% reduction of dystrophin levels. Genetic analyses revealed a non-sense mutation in exon 2 of the dystrophin gene. This mutation is predicted to result in a Duchenne phenotype, but resulted in a mild Becker muscular dystrophy with widespread muscle hypertrophy. We suggest...

  5. Wilson's disease caused by alternative splicing and Alu exonization due to a homozygous 3039-bp deletion spanning from intron 1 to exon 2 of the ATP7B gene.

    Science.gov (United States)

    Mameli, Eva; Lepori, Maria Barbara; Chiappe, Francesca; Ranucci, Giusy; Di Dato, Fabiola; Iorio, Raffaele; Loudianos, Georgios

    2015-09-15

    We describe a case of Wilson's disease (WD) diagnosed at 5 years after routine biochemical test showed increased aminotransferases. Mutation analysis of the ATP7B gene revealed a 3039-bp deletion in the homozygous state spanning from the terminal part of intron 1 to nt position 368 of exon 2. This deletion results in the activation of 3 cryptic splice sites: an AG acceptor splice site in nt positions 578-579 producing a different breakpoint and removing the first 577 nts of exon 2, an acceptor and a donor splice site in nt positions 20363-4 and 20456-7, respectively, in intron 1, resulting in the activation of a 94-bp cryptic Alu exon being incorporated into the mature transcript. The resulting alternative transcript contains a TAG stop codon in the first amino acid position of the cryptic exon, likely producing a truncated, non-functional protein. This study shows that intron exonization can also occur in humans through naturally occurring gross deletions. The results suggest that the combination of DNA and RNA analyses can be used for molecular characterization of gross ATP7B deletions, thus improving genetic counseling and diagnosis of WD. Moreover these studies help to better establish new molecular mechanisms producing Wilson's disease.

  6. Characterization of CaV1.2 exon 33 heterozygous knockout mice and negative correlation between Rbfox1 and CaV1.2 exon 33 expressions in human heart failure.

    Science.gov (United States)

    Wang, Juejin; Li, Guang; Yu, Dejie; Wong, Yuk Peng; Yong, Tan Fong; Liang, Mui Cheng; Liao, Ping; Foo, Roger; Hoppe, Uta C; Soong, Tuck Wah

    2017-09-26

    Recently, we reported that homozygous deletion of alternative exon 33 of CaV1.2 calcium channel in the mouse resulted in ventricular arrhythmias arising from increased CaV1.2Δ33 ICaL current density in the cardiomyocytes. We wondered whether heterozygous deletion of exon 33 might produce cardiac phenotype in a dose-dependent manner, and whether the expression levels of RNA splicing factors known to regulate alternative splicing of exon 33 might change in human heart failure. Unexpectedly, we found that exon 33(+/-) cardiomyocytes showed similar CaV1.2 channel properties as wild-type cardiomyocyte, even though CaV1.2Δ33 channels exhibit a gain-in-function. In human hearts, we found that the mRNA level of splicing factor Rbfox1, but not Rbfox2, was downregulated in dilated cardiomyopathy, and CACNA1C mRNA level was dramatically decreased in the both of dilated and ischemic cardiomyopathy. These data imply Rbfox1 may be involved in the development of cardiomyopathies via regulating the alternative splicing of CaV1.2 exon 33. (149 words).

  7. Clinical Characteristics and Outcomes of Lung Cancer Patients 
with EGFR Mutations in Exons 19 and 21

    Directory of Open Access Journals (Sweden)

    Renwang LIU

    2014-11-01

    Full Text Available Background and objective Studies on the epidermal growth factor receptor (EGFR signaling pathways and the therapeutic effects of EGFR-tyrosine kinase inhibitors (EGFR-TKIs have recently proven that targeted therapy has a major role in the treatment of lung cancer. However, the therapeutic effects of EGFR-TKIs on lung cancers with different EGFR mutation subtypes remain unclear. And if there is a significant difference in the effects of EGFR-TKIs, the mechanisms for the difference remain unclear. The aim of this study was to investigate the clinical importance of EGFR mutations in exons 19 and 21 of lung cancer patients and to compare the outcomes of these patients. Methods The study recruited 113 patients who had non-small cell lung cancer (NSCLC with EGFR mutations. EGFR mutations were detected for 47 patients using Real-time PCR or DNA sequencinag. The mutations of the remaining patients were determined using xTag-EGFR liquid chip technology. All stages I-III patients underwent radical resection followed by 4 cycles of postoperative chemotherapy. Patients with pleural metastases underwent pleural biopsy, pleurodesis, and chemotherapy only. Patients with distant metastases underwent biopsy and chemotherapy only. Collected clinical data were analyzed using SPSS 19.0 software. Results EGFR exon mutations 19 and 21 were found in 56 and 57 patients, respectively. The mean age of patients with exon 19 mutations was lower than the age of the patients with exon 21 mutations (57.02±11.31 years vs 62.25±7.76 years, respectively; P0.05 between the patients with exon 19 and 21 mutations; and survival analysis of 91 (80.5% patients with complete clinical data found no differences in overall survival. Stratification analysis found out that patients with exon 19 mutations had longer overall survival associated with age>61 years, male gender, ever smoking, and stage IV disease; although the differences were not significant. Conclusion Compared to the lung

  8. The multifunctional peptidylglycine alpha-amidating monooxygenase gene: exon/intron organization of catalytic, processing, and routing domains.

    Science.gov (United States)

    Ouafik, L H; Stoffers, D A; Campbell, T A; Johnson, R C; Bloomquist, B T; Mains, R E; Eipper, B A

    1992-10-01

    Peptidylglycine alpha-amidating monooxygenase (PAM; EC 1.14.17.3) is a multifunctional protein containing two enzymes that act sequentially to catalyze the alpha-amidation of neuroendocrine peptides. Peptidylglycine alpha-hydroxylating monooxygenase (PHM) catalyzes the first step of the reaction and is dependent on copper, ascorbate, and molecular oxygen. Peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL) catalyzes the second step of the reaction. Previous studies demonstrated that alternative splicing results in the production of bifunctional PAM proteins that are integral membrane or soluble proteins as well as soluble monofunctional PHM proteins. Rat PAM is encoded by a complex single copy gene that consists of 27 exons and encompasses more than 160 kilobases (kb) of genomic DNA. The 12 exons comprising PHM are distributed over at least 76 kb genomic DNA and range in size from 49-185 base pairs; four of the introns within the PHM domain are over 10 kb in length. Alternative splicing in the PHM region can result in a truncated, inactive PHM protein (rPAM-5), or a soluble, monofunctional PHM protein (rPAM-4) instead of a bifunctional protein. The eight exons comprising PAL are distributed over at least 19 kb genomic DNA. The exons encoding PAL range in size from 54-209 base pairs and have not been found to undergo alternative splicing. The PHM and PAL domains are separated by a single alternatively spliced exon surrounded by lengthy introns; inclusion of this exon results in the production of a form of PAM (rPAM-1) in which endoproteolytic cleavage at a paired basic site can separate the two catalytic domains. The exon following the PAL domain encodes the trans-membrane domain of PAM; alternative splicing at this site produces integral membrane or soluble PAM proteins. The COOH-terminal domain of PAM is comprised of a short exon subject to alternative splicing and a long exon encoding the final 68 amino acids present in all bifunctional PAM proteins along

  9. Imatinib dose escalation versus sunitinib as a second line treatment in KIT exon 11 mutated GIST: a retrospective analysis.

    Science.gov (United States)

    Vincenzi, Bruno; Nannini, Margherita; Fumagalli, Elena; Bronte, Giuseppe; Frezza, Anna Maria; De Lisi, Delia; Spalato Ceruso, Mariella; Santini, Daniele; Badalamenti, Giuseppe; Pantaleo, Maria Abbondanza; Russo, Antonio; Dei Tos, Angelo Paolo; Casali, Paolo; Tonini, Giuseppe

    2016-10-25

    We retrospectively reviewed data from 123 patients (KIT exon 11 mutated) who received sunitinib or dose-escalated imatinib as second line.All patients progressed on imatinib (400 mg/die) and received a second line treatment with imatinib (800 mg/die) or sunitinib (50 mg/die 4 weeks on/2 off or 37.5 mg/day). Deletion versus other KIT 11 mutation was recorded, correlated with clinical benefits.64% received imatinib, 36% sunitinib. KIT exon 11 mutation was available in 94 patients. With a median follow-up of 61 months, median time to progression (TTP) in patients receiving sunitinib and imatinib was 10 (95% CI 9.7-10.9) and 5 months (95% CI 3.6-6.7) respectively (P = 0.012). No difference was found in overall survival (OS) (P = 0.883). In imatinib arm, KIT exon 11 deletions was associated with a shorter TTP (7 vs 17 months; P = 0.02), with a trend in OS (54 vs 71 months P = 0.063). No difference was found in patients treated with sunitinib (P = 0.370).A second line with sunitinib was associated with an improved TTP in KIT exon 11 mutated patients progressing on imatinib 400 mg/die. Deletions in exon 11 seemed to be correlated with worse outcome in patients receiving imatinib-based second line.

  10. Dietary Methionine Affect Meat Qulity and Myostatin Gene Exon 1 Region Methylation in Skeletal Muscle Tissues of Broilers

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-qing; ZONG Kai; ZHANG Li-li; CAO Shu-qing

    2010-01-01

    Dietary amino acids imbalance will result in stunted broiler performance and deteriorated meat quality,which are involved in various biochemical cycles in vivo.In this study,the effects of dietary methionine on meat quality and methylation of myostatin exon 1 were investigated.Drip loss of the broilers fed with diet of high methionine levels(0.2%)increased from(6.3±0.1)%(control group)to(10.1±1.0)%,and the muscle shearing force increased from(22.8±1.9)N(control group)to(26.3±2.3)N.Moreover,many CpG sites were found at the myostatin exon 1 region(nucleotides 2360-2540 bp).To further understand the regulation of broiler myostatin expression,the methylation status of broiler myostatin exon 1 and its mRNA expression were analyzed.At the myostatin exon 1 region where CG enriches(nucleotides 2360-2540 bp),the percentages of methylation were 46 and 84% in low Met and high Met content groups after 55-d feeding,respectively.In skeletal muscle tissues,the exon 1 hypermethylation status of myostatin gene was found to be negatively correlated with the gene expression.These results suggested that methylation of this gene is a dynamic process,which plays a dominant role in regulating gene expression for development of individuals.

  11. GAA Deficiency in Pompe Disease Is Alleviated by Exon Inclusion in iPSC-Derived Skeletal Muscle Cells

    Directory of Open Access Journals (Sweden)

    Erik van der Wal

    2017-06-01

    Full Text Available Pompe disease is a metabolic myopathy caused by deficiency of the acid α-glucosidase (GAA enzyme and results in progressive wasting of skeletal muscle cells. The c.-32-13T>G (IVS1 GAA variant promotes exon 2 skipping during pre-mRNA splicing and is the most common variant for the childhood/adult disease form. We previously identified antisense oligonucleotides (AONs that promoted GAA exon 2 inclusion in patient-derived fibroblasts. It was unknown how these AONs would affect GAA splicing in skeletal muscle cells. To test this, we expanded induced pluripotent stem cell (iPSC-derived myogenic progenitors and differentiated these to multinucleated myotubes. AONs restored splicing in myotubes to a similar extent as in fibroblasts, suggesting that they act by modulating the action of shared splicing regulators. AONs targeted the putative polypyrimidine tract of a cryptic splice acceptor site that was part of a pseudo exon in GAA intron 1. Blocking of the cryptic splice donor of the pseudo exon with AONs likewise promoted GAA exon 2 inclusion. The simultaneous blocking of the cryptic acceptor and cryptic donor sites restored the majority of canonical splicing and alleviated GAA enzyme deficiency. These results highlight the relevance of cryptic splicing in human disease and its potential as therapeutic target for splicing modulation using AONs.

  12. DETECTION OF POINT MUTATIONS IN EXON 2 OF THE G6PD GENE IN CHINESE G6PD VARIANTS

    Institute of Scientific and Technical Information of China (English)

    许卫明; 王菁; 华小云; 杜传书

    1994-01-01

    In the past few years,a total of 6 different mutations of the G6PD gene have been reported in china.One of these,the C6 mutation(A95→G),accounted for about 15.4% of the Chinese G6PD variants.In ordet to develop a strategy for rapid detection of mutation-containing exons of the G6PD gene,we applied the single-strand confor-mation polymorphism(SSCP)technique to the detection of mutations in exon 2 of this gene.We observed four pa-tients with abnormal migration patterns of the exon 2 band among 20 cases of G6PD variants.Direct PCR se-quencing confirmed a Tto C substitution in exon 2 that has previously been reported.This procedure is therefore of particular importance for the rapid detection of mutation-containing exons in the G6PD gene.

  13. Identification of the uncommon allele HLA-A*7403 in a Caucasian renal transplant cadaveric donor: extension of the exon 4 sequence.

    Science.gov (United States)

    Canossi, A; Del Beato, T; Piazza, A; Liberatore, G; Ozzella, G; Tessitore, A; Adorno, D

    2007-06-01

    This report describes the unknown exon 4 sequence of the rare A*7403 allele, identified in a Caucasian renal transplant cadaveric donor from Italy. This sequence is identical to that of the only known A*7401 exon 4, and this result allowed us to confirm the hypothesis of the generation of A*7403 allele from the ancestor A*7402 by point mutation in exon 2.

  14. Alternative splicing of exon 17 and a missense mutation in exon 20 of the insulin receptor gene in two brothers with a novel syndrome of insulin resistance (congenital fiber-type disproportion myopathy)

    DEFF Research Database (Denmark)

    Vorwerk, P; Christoffersen, C T; Müller, J

    1999-01-01

    domain. In the correct spliced variant, the point mutation is silent and results in a normally translated IR. The paternal allele carries a missense mutation in the tyrosine kinase domain. All three cDNA variants were present in the lymphocytes of the patients. Purified IR from 293 cells overexpressing...... to be compound heterozygotes for mutations in the IR gene. The maternal allele was alternatively spliced in exon 17 due to a point mutation in the -1 donor splice site of the exon. The abnormal skipping of exon 17 shifts the amino acid reading frame and leads to a truncated IR, missing the entire tyrosine kinase...... either of the two mutated receptors lacked basal or stimulated IR beta-subunit autophosphorylation. A third brother who inherited both normal alleles has an normal muscle phenotype and insulin sensitivity, suggesting a direct linkage of these IR mutations with the CFTDM phenotype....

  15. Natural osmolytes remodel the aggregation pathway of mutant huntingtin exon 1.

    Science.gov (United States)

    Borwankar, Tejas; Röthlein, Christoph; Zhang, Gong; Techen, Anne; Dosche, Carsten; Ignatova, Zoya

    2011-03-29

    In response to stress small organic compounds termed osmolytes are ubiquitously accumulated in all cell types to regulate the intracellular solvent quality and to counteract the deleterious effect on the stability and function of cellular proteins. Given the evidence that destabilization of the native state of a protein either by mutation or by environmental changes triggers the aggregation in the neurodegenerative pathologies, the modulation of the intracellular solute composition with osmolytes is an attractive strategy to stabilize an aggregating protein. Here we report the effect of three natural osmolytes on the in vivo and in vitro aggregation landscape of huntingtin exon 1 implicated in the Huntington's disease. Trimethylamine N-oxide (TMAO) and proline redirect amyloid fibrillogenesis of the pathological huntingtin exon 1 to nonamyloidogenic amorphous assemblies via two dissimilar molecular mechanisms. TMAO causes a rapid formation of bulky amorphous aggregates with minimally exposed surface area, whereas proline solubilizes the monomer and suppresses the accumulation of early transient aggregates. Conversely, glycine-betaine enhances fibrillization in a fashion reminiscent of the genesis of functional amyloids. Strikingly, none of the natural osmolytes can completely abrogate the aggregate formation; however, they redirect the amyloidogenesis into alternative, nontoxic aggregate species. Our study reveals new insights into the complex interactions of osmoprotectants with polyQ aggregates.

  16. An Inframe Trinucleotide Deletion in MTRR Exon 1 is Associated with the Risk of Spina Bifida.

    Science.gov (United States)

    Zhang, Jun; Dai, Xiao-Lu; Liu, Gui-Cen; Wang, Juan; Ren, Xue-Yi; Jin, Mu-Hua; Mi, Nan-Nan; Wang, Shu-Qin

    2017-07-15

    Maternal genetic variants of enzymes in folate-homocysteine metabolic network are significantly correlative with the risk of spina bifida. To survey the genetic causality, the genotypes of three women having spina bifida fetuses from two unrelated Chinese families were screened in candidate alleles. Polymerase chain reaction, capillary electrophoresis and Sanger sequencing were employed to recognize the allelic variation. A trinucleotide deletion (c.4_6delAGG) was identified in the first exon of MTRR. All the three women showed the novel clinical variation including one heterozygous and two homozygous. The siblings who had healthy babies from the same families did not harbor the variation. In the unaffected control individuals, the variant was also not observed. Eukaryotic expression and bioinformatics techniques were utilized to explore the molecular pathogenesis of the potential genetic risk of developing spina bifida. Exceptionally, the functional examination revealed that the Arg2del variant kept subcellular localization unaltered with catalytic activity intact, but failed to efficiently activate MTR compared with the wild type. Genetic disorder of folate and homocysteine metabolism during pregnancy is believed to be associated with folate-sensitive neural tube defects. The report highlights that the inframe deletion in MTRR exon 1 could be a high risk factor susceptibility to spina bifida.

  17. Selection preserves Ubiquitin Specific Protease 4 alternative exon skipping in therian mammals.

    Science.gov (United States)

    Vlasschaert, Caitlyn; Xia, Xuhua; Gray, Douglas A

    2016-02-02

    Ubiquitin specific protease 4 (USP4) is a highly networked deubiquitinating enzyme with reported roles in cancer, innate immunity and RNA splicing. In mammals it has two dominant isoforms arising from inclusion or skipping of exon 7 (E7). We evaluated two plausible mechanisms for the generation of these isoforms: (A) E7 skipping due to a long upstream intron and (B) E7 skipping due to inefficient 5' splice sites (5'SS) and/or branchpoint sites (BPS). We then assessed whether E7 alternative splicing is maintained by selective pressure or arose from genetic drift. Both transcript variants were generated from a USP4-E7 minigene construct with short flanking introns, an observation consistent with the second mechanism whereby differential splice signal strengths are the basis of E7 skipping. Optimization of the downstream 5'SS eliminated E7 skipping. Experimental validation of the correlation between 5'SS identity and exon skipping in vertebrates pinpointed the +6 site as the key splicing determinant. Therian mammals invariably display a 5'SS configuration favouring alternative splicing and the resulting isoforms have distinct subcellular localizations. We conclude that alternative splicing of mammalian USP4 is under selective maintenance and that long and short USP4 isoforms may target substrates in various cellular compartments.

  18. Polymorphysims of Gene in the Exons Were Associated with the Reproductive Endocrine of Japanese Flounder (

    Directory of Open Access Journals (Sweden)

    R. Q. Ma

    2012-06-01

    Full Text Available The cytochrome P450c17-I (CYP17-I is one of the enzymes critical to gonadal development and the synthesis of androgens. Two single nucleotide polymorphisms (SNPs were detected within the coding region of the CYP17-I gene in a population of 75 male Japanese flounder (Paralichthys olivaceus. They were SNP1 (c.C445T located in exon2 and SNP2 (c.T980C (p.Phe307Leu located in exon5. Four physiological indices, which were serum testosterone (T, serum 17β-estradiol (E2, Hepatosomatic index (HSI, and Gonadosomatic index (GSI, were studied to examine the effect of the two SNPs on the reproductive endocrines of Japanese flounder. Multiple comparisons revealed that CT genotype of SNP1 had a much lower T level than CC genotype (p<0.05 and the GSI of individuals with CC genotype of SNP2 was higher than those with TT genotype (p<0.05. Four diplotypes were constructed based on the two SNPs and the diplotype D3 had a significantly lower T level and GSI. In conclusion, the two SNPs were significantly associated with reproductive traits of Japanese flounder.

  19. Detection of c-kit gene mutations in Exon 11 of Leukemias

    Directory of Open Access Journals (Sweden)

    Syed Rizwan Hussain

    2012-03-01

    Full Text Available METHODS: In order to determine the frequency of mutations of Exon 11 of c-kit gene in 50 Leukemia cases (31 samples Acute Myeloid Leukemia, 5 samples Acute Lymphoblastic Leukemia, 9 samples Chronic Myeloid Leukemia and 5 samples Chronic Lymphocytic Leukemia, we have done PCR-SSCP followed by direct DNA sequencing. RESULTS: Of 50 Leukemia cases, 28 were male and 22 were female with ages ranging from 2 to 65 years. The mean age of cases was 31.88 years. We have detected total twenty mutations in nineteen cases that include Lys550Asn, Tyr568Ser, Ile571Thr, Thr574Pro, Gln575His, Tyr578Pro, Asp579His, His580Gln, Arg586Thr, Asn587Asp and Arg588Met as well as novel point mutations at codons Ile563Lys, Val569Leu, Tyr570Ser, and Pro577Ser. Ile571Leu substitution is found in two independent cases whereas Trp582Ser substitution is found in three individual cases. CONCLUSION: These observations suggest that mutations in exon 11 of the c-kit gene might represent useful molecular genetic markers in Leukemia.

  20. Highly Sensitive and Reliable Detection of EGFR Exon 19 Deletions by Droplet Digital Polymerase Chain Reaction.

    Science.gov (United States)

    Oskina, Natalya; Oscorbin, Igor; Khrapov, Evgeniy; Boyarskikh, Ulyana; Subbotin, Dmitriy; Demidova, Irina; Imyanitov, Evgeny; Filipenko, Maxim

    2017-06-06

    Analysis of EGFR mutations is becoming a routine clinical practice but the optimal EGFR mutation testing method is still to be determined. We determined the nucleotide sequence of deletions located in exon 19 of the EGFR gene in lung tumor samples of patients residing in different regions of Russia (153 tumor DNA specimens), using Sanger sequencing. We developed a droplet digital polymerase chain reaction assay capable of detecting all common EGFR deletions in exon 19. We also compared the therascreen amplification refractory mutation system assay with a droplet digital polymerase chain reaction assay for the detection of all the deletions in our study. The droplet digital polymerase chain reaction assay demonstrated 100% sensitivity against polymerase chain reaction fragment length analysis and detected all possible types of deletions revealed in our study (22 types). At the same time, the therascreen EGFR RGQ PCR Kit was not able to detect deletions c.2252-2276>A and c.2253-2276 and showed low performance for another long deletion. Thus, we can conclude that the extraordinary length of deletions and their atypical locations (shift at the 3'-region compared to known deletions) could be problematic for the therascreen EGFR RGQ PCR Kit and should be taken into account during targeted mutation test development. However, droplet digital polymerase chain reaction is a promising and reliable assay that can be used as a diagnostic tool to genotype formalin-fixed paraffin-embedded cancer samples for EGFR or another clinically relevant somatic mutation.

  1. SinEx DB: a database for single exon coding sequences in mammalian genomes.

    Science.gov (United States)

    Jorquera, Roddy; Ortiz, Rodrigo; Ossandon, F; Cárdenas, Juan Pablo; Sepúlveda, Rene; González, Carolina; Holmes, David S

    2016-01-01

    Eukaryotic genes are typically interrupted by intragenic, noncoding sequences termed introns. However, some genes lack introns in their coding sequence (CDS) and are generally known as 'single exon genes' (SEGs). In this work, a SEG is defined as a nuclear, protein-coding gene that lacks introns in its CDS. Whereas, many public databases of Eukaryotic multi-exon genes are available, there are only two specialized databases for SEGs. The present work addresses the need for a more extensive and diverse database by creating SinEx DB, a publicly available, searchable database of predicted SEGs from 10 completely sequenced mammalian genomes including human. SinEx DB houses the DNA and protein sequence information of these SEGs and includes their functional predictions (KOG) and the relative distribution of these functions within species. The information is stored in a relational database built with My SQL Server 5.1.33 and the complete dataset of SEG sequences and their functional predictions are available for downloading. SinEx DB can be interrogated by: (i) a browsable phylogenetic schema, (ii) carrying out BLAST searches to the in-house SinEx DB of SEGs and (iii) via an advanced search mode in which the database can be searched by key words and any combination of searches by species and predicted functions. SinEx DB provides a rich source of information for advancing our understanding of the evolution and function of SEGs.Database URL: www.sinex.cl.

  2. Biased exon/intron distribution of cryptic and de novo 3' splice sites.

    Science.gov (United States)

    Královicová, Jana; Christensen, Mikkel B; Vorechovský, Igor

    2005-01-01

    We compiled sequences of previously published aberrant 3' splice sites (3'ss) that were generated by mutations in human disease genes. Cryptic 3'ss, defined here as those resulting from a mutation of the 3'YAG consensus, were more frequent in exons than in introns. They clustered in approximately 20 nt region adjacent to authentic 3'ss, suggesting that their under-representation in introns is due to a depletion of AG dinucleotides in the polypyrimidine tract (PPT). In contrast, most aberrant 3'ss that were induced by mutations outside the 3'YAG consensus (designated 'de novo') were in introns. The activation of intronic de novo 3'ss was largely due to AG-creating mutations in the PPT. In contrast, exonic de novo 3'ss were more often induced by mutations improving the PPT, branchpoint sequence (BPS) or distant auxiliary signals, rather than by direct AG creation. The Shapiro-Senapathy matrix scores had a good prognostic value for cryptic, but not de novo 3'ss. Finally, AG-creating mutations in the PPT that produced aberrant 3'ss upstream of the predicted BPS in vivo shared a similar 'BPS-new AG' distance. Reduction of this distance and/or the strength of the new AG PPT in splicing reporter pre-mRNAs improved utilization of authentic 3'ss, suggesting that AG-creating mutations that are located closer to the BPS and are preceded by weaker PPT may result in less severe splicing defects.

  3. Growth hormone receptor exon 3 isoforms and their implication in growth disorders and treatment.

    Science.gov (United States)

    Jorge, Alexander A L; Arnhold, Ivo J P

    2009-04-01

    Human recombinant growth hormone (hGH) has been used to treat short stature in several different conditions, but considerable inter-individual variation in short- and long-term growth response exists. Pharmacogenomics can provide important insights into hGH therapy. The GH receptor (GHR) is the first key molecule mediating GH action. In the past 3 years, a common GHR polymorphism reflecting the presence (GHRfl) or absence (GHRd3) of exon 3 has been under intensive investigation regarding its influence on the response to hGH therapy. Studies that evaluated response to GH treatment determined by these two GHR isoforms in children with GH deficiency, girls with Turner syndrome, children born small for gestational age and patients with acromegaly showed that patients carrying the GHRd3 allele demonstrated a greater GH sensitivity than patients homozygous for the GHRfl allele. Other studies presented contradictory data, however, which may be caused by confounding factors such as small sample sizes and differences in experimental design. This GHR exon 3 genotype is the first identified genetic factor found to modulate the individual response to GH therapy. This article reviews the historical aspects and pharmacogenetic studies published to date in relation to this GHR polymorphism. The analyses of present and future validation studies may define the use of this and other polymorphisms in clinical practice, moving from pharmacogenetics to routine application and allowing individualization of hGH doses to optimize final outcome.

  4. Characterization of a silencer element in the first exon of the human osteocalcin gene.

    Science.gov (United States)

    Li, Y P; Chen, W; Stashenko, P

    1995-01-01

    Osteocalcin, the major non-collagenous protein in bone, is transcribed in osteoblasts at the onset of extracellular matrix mineralization. In this study it was demonstrated that sequences located in the first exon of the human osteocalcin gene possess a differentiation-related osteocalcin silencer element (OSE). Osteocalcin was rendered transcribable in UMR-106 cells and proliferating normal osteoblasts after deletion of the -3 to +51 region. Site-specific mutagenesis of this region revealed that a 7 bp sequence (TGGCCCT) (+29 to +35) is critical for silencing function. Mobility shift assays demonstrated that a nuclear factor bound to the OSE. The OSE binding protein was present in proliferating normal pre-osteoblasts and in UMR-106 and ROS 17/2.8 osteosarcoma cells, but was absent from post-proliferative normal osteoblasts. The binding protein was inhibited by fragments containing the +29/+35 sequence, but not by other promoter fragments or by the consensus oligomers of unrelated nuclear factors AP-1 and Sp1. DNase 1 footprinting demonstrated that the OSE binding-protein protected the +17 to +36 portion of the first exon, consistent with the results of mapping studies and competitive mobility shift assays. It is hypothesized that this silencer is activated by complexing of the OSE binding protein to the OSE during the osteoblast proliferation stage and that the OSE binding protein is down-regulated at the onset of extracellular matrix mineralization. Images PMID:8559666

  5. Assembly of splicing complexes on exon 11 of the human insulin receptor gene does not correlate with splicing efficiency in-vitro

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    Caples Matt

    2004-07-01

    Full Text Available Abstract Background Incorporation of exon 11 of the insulin receptor gene is both developmentally and hormonally-regulated. Previously, we have shown the presence of enhancer and silencer elements that modulate the incorporation of the small 36-nucleotide exon. In this study, we investigated the role of inherent splice site strength in the alternative splicing decision and whether recognition of the splice sites is the major determinant of exon incorporation. Results We found that mutation of the flanking sub-optimal splice sites to consensus sequences caused the exon to be constitutively spliced in-vivo. These findings are consistent with the exon-definition model for splicing. In-vitro splicing of RNA templates containing exon 11 and portions of the upstream intron recapitulated the regulation seen in-vivo. Unexpectedly, we found that the splice sites are occupied and spliceosomal complex A was assembled on all templates in-vitro irrespective of splicing efficiency. Conclusion These findings demonstrate that the exon-definition model explains alternative splicing of exon 11 in the IR gene in-vivo but not in-vitro. The in-vitro results suggest that the regulation occurs at a later step in spliceosome assembly on this exon.

  6. Exon definition complexes contain the tri-snRNP and can be directly converted into B-like precatalytic splicing complexes.

    Science.gov (United States)

    Schneider, Marc; Will, Cindy L; Anokhina, Maria; Tazi, Jamal; Urlaub, Henning; Lührmann, Reinhard

    2010-04-23

    The first step in splicing of pre-mRNAs with long introns is exon definition, where U1 and U2 snRNPs bind at opposite ends of an exon. After exon definition, these snRNPs must form a complex across the upstream intron to allow splicing catalysis. Exon definition and conversion of cross-exon to cross-intron spliceosomal complexes are poorly understood. Here we demonstrate that, in addition to U1 and U2 snRNPs, cross-exon complexes contain U4, U5, and U6 (which form the tri-snRNP). Tri-snRNP docking involves the formation of U2/U6 helix II. This interaction is stabilized by a 5' splice site (SS)-containing oligonucleotide, which can bind the tri-snRNP and convert the cross-exon complex into a cross-intron, B-like complex. Our data suggest that the switch from cross-exon to cross-intron complexes can occur directly when an exon-bound tri-snRNP interacts with an upstream 5'SS, without prior formation of a cross-intron A complex, revealing an alternative spliceosome assembly pathway.

  7. Point mutation in exon 4 of presenilin-1 gene and early-onset familial Alzheimer disease

    Institute of Scientific and Technical Information of China (English)

    Yu Liao; Fan Zhao

    2006-01-01

    BACKGROUND:A total of 50 missense mutations of presenilin-1 (PS-1) have been found thus far in early-onset familial Alzheimer disease(EOFAD),PS-1 gene might be a causative gene for Chinese EOFAD.OBJECTIVE:To investigate mutation of PS-1 gene in the blood of Chinese patients with familial Alzheimer disease(FAD).DESIGN:A design with randomized control and repeated sequencing.SETTlNG:Department of Neurology,the Second People's Hospital of Wuxi.PARTICIPANTS:The experiment was carried out in Huaihua Hospital Affiliated to Nanhua University in September 1993.Eight FAD patients were graded as FAD group.There were 6 males and 2 females with the mean age of(36±16)years.The control group was composed of 42 persons,including 8 hospitalized SAD patients diagnosed according to the criteria of Practical Neuralgia and conformed to the revised fourth edition of the Diagnostic and Statistical Manual of Mental Disorders(DCM-Ⅳ-TR),11 dementia patients caused by multipie cerebral infarction,13 normal persons in the FAD family mentioned above family,and 10 normal healthy adults provided by the health examination section of our hospital.METHODS:GeneAmp PCR System 2400 (Applied Biosystems,USA),DNA-Sequencer Model 310(Perkin Elmer,USA),Taq DNA Polymerase(Fermentas,Canada).All reagents used for DNA extraction were prepared with analytical reagents manufactured in China.The samples were stratified carefully,collected the leukocytic cream from the interface,added STMT to each sample and vortexed to suspend evenly.Then the samples were centrifugated.The nuclear pellet was resuspended in digestion solution with proteinase K and incubated under appropriate condition.Genomic DNA was extract with phenol/chloroform,precipitated with dehvdraled ethanol,and washed with 70%sterilized ethanol.Finally,genomic DNA was dissolved in ultra pure water and stored for Iater use.The sequences were 5'-ACT AAC AAT GGA TGA CCT GGT GAA ATC-3'and 3'-ACG GTC TGA CCT AAG TGA ATA GTA GAG-5' to flank the exon 2 of

  8. Random Splicing of Several Exons Caused by a Single Base Change in the Target Exon of CRISPR/Cas9 Mediated Gene Knockout

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    Marcel Kapahnke

    2016-12-01

    Full Text Available The clustered regularly interspaced short palindromic repeats (CRISPR-associated sequence 9 (CRISPR/Cas9 system is widely used for genome editing purposes as it facilitates an efficient knockout of a specific gene in, e.g. cultured cells. Targeted double-strand breaks are introduced to the target sequence of the guide RNAs, which activates the cellular DNA repair mechanism for non-homologous-end-joining, resulting in unprecise repair and introduction of small deletions or insertions. Due to this, sequence alterations in the coding region of the target gene frequently cause frame-shift mutations, facilitating degradation of the mRNA. We here show that such CRISPR/Cas9-mediated alterations in the target exon may also result in altered splicing of the respective pre-mRNA, most likely due to mutations of splice-regulatory sequences. Using the human FLOT-1 gene as an example, we demonstrate that such altered splicing products also give rise to aberrant protein products. These may potentially function as dominant-negative proteins and thus interfere with the interpretation of the data generated with these cell lines. Since most researchers only control the consequences of CRISPR knockout at genomic and protein level, our data should encourage to also check the alterations at the mRNA level.

  9. Single exon mutation in arylsulfatase A gene has two effects: loss of enzyme activity and aberrant splicing.

    Science.gov (United States)

    Hasegawa, Y; Kawame, H; Ida, H; Ohashi, T; Eto, Y

    1994-04-01

    The arylsulfatase A gene of a Japanese patient who has the juvenile form of metachromatic leukodystrophy, and who has been previously reported as a heterozygote of the 1070A mutation, was investigated. Nucleotide sequence analysis revealed the presence of a previously unreported C-to-T substitution (designated 2330T), 22 nucleotides downstream from the exon 8 splice acceptor site. Although the 2330T mutation itself results in a single amino acid substitution of Thr409 by Ile, the analysis of the patient's cDNA fragments amplified by the reverse transcription-polymerase chain reaction revealed that transcripts of the 2330T allele were spliced both normally and aberrantly. The aberrant splicing produced a 27-nucleotide deletion from the usual exon 8 splice acceptor site. These results indicate that the new mutation is a rare case of an exon mutation affecting splice site selection. The mechanism of this aberrant pre-mRNA splicing is discussed.

  10. Common N-acetylgalactosamine-6-sulfate sulfatase (GALNS exon mutations in Brazilian patients with mucopolysaccharidosis IVA (MPS IVA

    Directory of Open Access Journals (Sweden)

    Tatiana Dieter

    2007-01-01

    Full Text Available Morquio A Syndrome (mucopolysaccharidosis IVA - MPS IVA, OMIM# 253000 is an autosomal recessive inborn error of metabolism caused by the deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS. We investigated five unrelated Brazilian MPS IVA families for mutations in exons 4, 5, 9 and 10 of the GALNS gene. Six out of the 10 mutant alleles were identified. Taken together with a previous study, which included six unrelated families, common mutations among Brazilian patients were p.N164T, p.G116S and p.G301C. Among one hundred control subjects three novel silent mutations were found (p.A107A; GCC -> GCT, p.Y108Y; TAC -> TAT, p.P357P; CCG -> CCA. Screening starting with exons 4, 5, 9, 10 and 11 may be a good strategy for genotyping of Brazilian patients since these exons include 73% of all mutations identified in the current and previous studies.

  11. Novel Cationic Carotenoid Lipids as Delivery Vectors of Antisense Oligonucleotides for Exon Skipping in Duchenne Muscular Dystrophy

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    Vassilia Partali

    2012-01-01

    Full Text Available Duchenne Muscular Dystrophy (DMD is a common, inherited, incurable, fatal muscle wasting disease caused by deletions that disrupt the reading frame of the DMD gene such that no functional dystrophin protein is produced. Antisense oligonucleotide (AO-directed exon skipping restores the reading frame of the DMD gene, and truncated, yet functional dystrophin protein is expressed. The aim of this study was to assess the efficiency of two novel rigid, cationic carotenoid lipids, C30-20 and C20-20, in the delivery of a phosphorodiamidate morpholino (PMO AO, specifically designed for the targeted skipping of exon 45 of DMD mRNA in normal human skeletal muscle primary cells (hSkMCs. The cationic carotenoid lipid/PMO-AO lipoplexes yielded significant exon 45 skipping relative to a known commercial lipid, 1,2-dimyristoyl-sn-glycero-3-ethylphosphocholine (EPC.

  12. AON-mediated Exon Skipping Restores Ciliation in Fibroblasts Harboring the Common Leber Congenital Amaurosis CEP290 Mutation

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    Xavier Gerard

    2012-01-01

    Full Text Available Leber congenital amaurosis (LCA is a severe hereditary retinal dystrophy responsible for congenital or early-onset blindness. The most common disease-causing mutation (>10% is located deep in intron 26 of the CEP290 gene (c.2991+1655A>G. It creates a strong splice donor site that leads to insertion of a cryptic exon encoding a premature stop codon. In the present study, we show that the use of antisense oligonucleotides (AONs allow an efficient skipping of the mutant cryptic exon and the restoration of ciliation in fibroblasts of affected patients. These data support the feasibility of an AON-mediated exon skipping strategy to correct the aberrant splicing.

  13. Comparison of Affymetrix Gene Array with the Exon Array shows potential application for detection of transcript isoform variation

    Directory of Open Access Journals (Sweden)

    Coulombe-Huntington Jasmin

    2009-11-01

    Full Text Available Abstract Background The emergence of isoform-sensitive microarrays has helped fuel in-depth studies of the human transcriptome. The Affymetrix GeneChip Human Exon 1.0 ST Array (Exon Array has been previously shown to be effective in profiling gene expression at the isoform level. More recently, the Affymetrix GeneChip Human Gene 1.0 ST Array (Gene Array has been released for measuring gene expression and interestingly contains a large subset of probes from the Exon Array. Here, we explore the potential of using Gene Array probes to assess expression variation at the sub-transcript level. Utilizing datasets of the high quality Microarray Quality Control (MAQC RNA samples previously assayed on the Exon Array and Gene Array, we compare the expression measurements of the two platforms to determine the performance of the Gene Array in detecting isoform variations. Results Overall, we show that the Gene Array is comparable to the Exon Array in making gene expression calls. Moreover, to examine expression of different isoforms, we modify the Gene Array probe set definition file to enable summarization of probe intensity values at the exon level and show that the expression profiles between the two platforms are also highly correlated. Next, expression calls of previously known differentially spliced genes were compared and also show concordant results. Splicing index analysis, representing estimates of exon inclusion levels, shows a lower but good correlation between platforms. As the Gene Array contains a significant subset of probes from the Exon Array, we note that, in comparison, the Gene Array overlaps with fewer but still a high proportion of splicing events annotated in the Known Alt Events UCSC track, with abundant coverage of cassette exons. We discuss the ability of the Gene Array to detect alternative splicing and isoform variation and address its limitations. Conclusion The Gene Array is an effective expression profiling tool at gene and

  14. Exonic Splicing Mutations Are More Prevalent than Currently Estimated and Can Be Predicted by Using In Silico Tools.

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    Omar Soukarieh

    2016-01-01

    Full Text Available The identification of a causal mutation is essential for molecular diagnosis and clinical management of many genetic disorders. However, even if next-generation exome sequencing has greatly improved the detection of nucleotide changes, the biological interpretation of most exonic variants remains challenging. Moreover, particular attention is typically given to protein-coding changes often neglecting the potential impact of exonic variants on RNA splicing. Here, we used the exon 10 of MLH1, a gene implicated in hereditary cancer, as a model system to assess the prevalence of RNA splicing mutations among all single-nucleotide variants identified in a given exon. We performed comprehensive minigene assays and analyzed patient's RNA when available. Our study revealed a staggering number of splicing mutations in MLH1 exon 10 (77% of the 22 analyzed variants, including mutations directly affecting splice sites and, particularly, mutations altering potential splicing regulatory elements (ESRs. We then used this thoroughly characterized dataset, together with experimental data derived from previous studies on BRCA1, BRCA2, CFTR and NF1, to evaluate the predictive power of 3 in silico approaches recently described as promising tools for pinpointing ESR-mutations. Our results indicate that ΔtESRseq and ΔHZEI-based approaches not only discriminate which variants affect splicing, but also predict the direction and severity of the induced splicing defects. In contrast, the ΔΨ-based approach did not show a compelling predictive power. Our data indicates that exonic splicing mutations are more prevalent than currently appreciated and that they can now be predicted by using bioinformatics methods. These findings have implications for all genetically-caused diseases.

  15. De novo exon 1 missense mutations of SKI and Shprintzen-Goldberg syndrome: two new cases and a clinical review.

    Science.gov (United States)

    Au, P Y Billie; Racher, Hilary E; Graham, John M; Kramer, Nancy; Lowry, R Brian; Parboosingh, Jillian S; Innes, A Micheil

    2014-03-01

    Shprintzen-Goldberg syndrome (OMIM #182212) is a connective tissue disorder characterized by craniosynostosis, distinctive craniofacial features, skeletal abnormalities, marfanoid body habitus, aortic dilatation, and intellectual disability. Mutations in exon 1 of SKI have recently been identified as being responsible for approximately 90% of reported individuals diagnosed clinically with Shprintzen-Goldberg syndrome. SKI is a known regulator of TGFβ signaling. Therefore, like Marfan syndrome and Loeys-Dietz syndrome, Shprintzen-Goldberg syndrome is likely caused by deregulated TGFβ signals, explaining the considerable phenotypic overlap between these three disorders. We describe two additional patients with exon 1 SKI mutations and review the clinical features and literature of Shprintzen-Goldberg syndrome.

  16. Screening the dystrophin gene suggests a high rate of polymorphism in general but no exonic deletions in schizophrenics

    Energy Technology Data Exchange (ETDEWEB)

    Lindor, N.M.; Sobell, J.L.; Thibodeau, S.N. [Mayo Clinic/Foundation, Rochester, MN (United States)] [and others

    1994-03-15

    The dystrophin gene, located at chromosome Xp21, was evaluated as a candidate gene in chronic schizophrenia in response to the report of a large family in which schizophrenia cosegregated with Becker muscular dystrophy. Genomic DNA from 94 men with chronic schizophrenia was evaluated by Southern blot analysis using cDNA probes that span exons 1-59. No exonic deletions were identified. An unexpectedly high rate of polymorphism was calculated in this study and two novel polymorphisms were found, demonstrating the usefulness of the candidate gene approach even when results of the original study are negative. 41 refs., 1 fig., 4 tabs.

  17. Revised genomic structure of the human ghrelin gene and identification of novel exons, alternative splice variants and natural antisense transcripts

    Directory of Open Access Journals (Sweden)

    Herington Adrian C

    2007-08-01

    Full Text Available Abstract Background Ghrelin is a multifunctional peptide hormone expressed in a range of normal tissues and pathologies. It has been reported that the human ghrelin gene consists of five exons which span 5 kb of genomic DNA on chromosome 3 and includes a 20 bp non-coding first exon (20 bp exon 0. The availability of bioinformatic tools enabling comparative analysis and the finalisation of the human genome prompted us to re-examine the genomic structure of the ghrelin locus. Results We have demonstrated the presence of an additional novel exon (exon -1 and 5' extensions to exon 0 and 1 using comparative in silico analysis and have demonstrated their existence experimentally using RT-PCR and 5' RACE. A revised exon-intron structure demonstrates that the human ghrelin gene spans 7.2 kb and consists of six rather than five exons. Several ghrelin gene-derived splice forms were detected in a range of human tissues and cell lines. We have demonstrated ghrelin gene-derived mRNA transcripts that do not code for ghrelin, but instead may encode the C-terminal region of full-length preproghrelin (C-ghrelin, which contains the coding region for obestatin and a transcript encoding obestatin-only. Splice variants that differed in their 5' untranslated regions were also found, suggesting a role of these regions in the post-transcriptional regulation of preproghrelin translation. Finally, several natural antisense transcripts, termed ghrelinOS (ghrelin opposite strand transcripts, were demonstrated via orientation-specific RT-PCR, 5' RACE and in silico analysis of ESTs and cloned amplicons. Conclusion The sense and antisense alternative transcripts demonstrated in this study may function as non-coding regulatory RNA, or code for novel protein isoforms. This is the first demonstration of putative obestatin and C-ghrelin specific transcripts and these findings suggest that these ghrelin gene-derived peptides may also be produced independently of preproghrelin

  18. Identification of evolutionarily conserved exons as regulated targets for the splicing activator tra2β in development.

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    Sushma Grellscheid

    2011-12-01

    Full Text Available Alternative splicing amplifies the information content of the genome, creating multiple mRNA isoforms from single genes. The evolutionarily conserved splicing activator Tra2β (Sfrs10 is essential for mouse embryogenesis and implicated in spermatogenesis. Here we find that Tra2β is up-regulated as the mitotic stem cell containing population of male germ cells differentiate into meiotic and post-meiotic cells. Using CLIP coupled to deep sequencing, we found that Tra2β binds a high frequency of exons and identified specific G/A rich motifs as frequent targets. Significantly, for the first time we have analysed the splicing effect of Sfrs10 depletion in vivo by generating a conditional neuronal-specific Sfrs10 knock-out mouse (Sfrs10(fl/fl; Nestin-Cre(tg/+. This mouse has defects in brain development and allowed correlation of genuine physiologically Tra2β regulated exons. These belonged to a novel class which were longer than average size and importantly needed multiple cooperative Tra2β binding sites for efficient splicing activation, thus explaining the observed splicing defects in the knockout mice. Regulated exons included a cassette exon which produces a meiotic isoform of the Nasp histone chaperone that helps monitor DNA double-strand breaks. We also found a previously uncharacterised poison exon identifying a new pathway of feedback control between vertebrate Tra2 proteins. Both Nasp-T and the Tra2a poison exon are evolutionarily conserved, suggesting they might control fundamental developmental processes. Tra2β protein isoforms lacking the RRM were able to activate specific target exons indicating an additional functional role as a splicing co-activator. Significantly the N-terminal RS1 domain conserved between flies and humans was essential for the splicing activator function of Tra2β. Versions of Tra2β lacking this N-terminal RS1 domain potently repressed the same target exons activated by full-length Tra2β protein.

  19. Deletion of twenty seven nucleotides within exon 11 of the band 3 gene identified in ovalocytosis in Lombok Island, Indonesia.

    Science.gov (United States)

    Alimsardjono, H; Mukono, I S; Dachlan, Y P; Matsuo, M

    1997-03-01

    This study reports the molecular characterization of ovalocytosis in Lombok Island, Indonesia. The analysis of genomic DNA by polymerase chain reaction shows that all 21 ovalocytotic individuals have two amplified products of different size from a region encompassing exon 11 of the band 3 gene. The sequence of the larger product matched perfectly with that of normal individuals. In the sequence of the smaller product, 27 nucleotides within exon 11 were deleted. The heterozygous presence of the deletion identified in other parts of Southeast Asia was confirmed in patients with ovalocytosis in an isolated island of eastern Indonesia.

  20. Two genetic determinants acquired late in Mus evolution regulate the inclusion of exon 5, which alters mouse APOBEC3 translation efficiency.

    Directory of Open Access Journals (Sweden)

    Jun Li

    2012-01-01

    Full Text Available Mouse apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like editing complex 3 (mA3, an intracellular antiviral factor, has 2 allelic variations that are linked with different susceptibilities to beta- and gammaretrovirus infections among various mouse strains. In virus-resistant C57BL/6 (B6 mice, mA3 transcripts are more abundant than those in susceptible BALB/c mice both in the spleen and bone marrow. These strains of mice also express mA3 transcripts with different splicing patterns: B6 mice preferentially express exon 5-deficient (Δ5 mA3 mRNA, while BALB/c mice produce exon 5-containing full-length mA3 mRNA as the major transcript. Although the protein product of the Δ5 mRNA exerts stronger antiretroviral activities than the full-length protein, how exon 5 affects mA3 antiviral activity, as well as the genetic mechanisms regulating exon 5 inclusion into the mA3 transcripts, remains largely uncharacterized. Here we show that mA3 exon 5 is indeed a functional element that influences protein synthesis at a post-transcriptional level. We further employed in vitro splicing assays using genomic DNA clones to identify two critical polymorphisms affecting the inclusion of exon 5 into mA3 transcripts: the number of TCCT repeats upstream of exon 5 and the single nucleotide polymorphism within exon 5 located 12 bases upstream of the exon 5/intron 5 boundary. Distribution of the above polymorphisms among different Mus species indicates that the inclusion of exon 5 into mA3 mRNA is a relatively recent event in the evolution of mice. The widespread geographic distribution of this exon 5-including genetic variant suggests that in some Mus populations the cost of maintaining an effective but mutagenic enzyme may outweigh its antiviral function.

  1. Digital Droplet PCR for the Absolute Quantification of Exon Skipping Induced by Antisense Oligonucleotides in (Pre-)Clinical Development for Duchenne Muscular Dystrophy

    Science.gov (United States)

    Verheul, Ruurd C.; van Deutekom, Judith C. T.; Datson, Nicole A.

    2016-01-01

    Antisense oligonucleotides (AONs) in clinical development for Duchenne muscular dystrophy (DMD) aim to induce skipping of a specific exon of the dystrophin transcript during pre-mRNA splicing. This results in restoration of the open reading frame and consequently synthesis of a dystrophin protein with a shorter yet functional central rod domain. To monitor the molecular therapeutic effect of exon skip-inducing AONs in clinical studies, accurate quantification of pre- and post-treatment exon skip levels is required. With the recent introduction of 3rd generation digital droplet PCR (ddPCR), a state-of-the-art technology became available which allows absolute quantification of transcript copy numbers with and without specific exon skip with high precision, sensitivity and reproducibility. Using Taqman assays with probes targeting specific exon-exon junctions, we here demonstrate that ddPCR reproducibly quantified cDNA fragments with and without exon 51 of the DMD gene over a 4-log dynamic range. In a comparison of conventional nested PCR, qPCR and ddPCR using cDNA constructs with and without exon 51 mixed in different molar ratios using, ddPCR quantification came closest to the expected outcome over the full range of ratios (0–100%), while qPCR and in particular nested PCR overestimated the relative percentage of the construct lacking exon 51. Highest accuracy was similarly obtained with ddPCR in DMD patient-derived muscle cells treated with an AON inducing exon 51 skipping. We therefore recommend implementation of ddPCR for quantification of exon skip efficiencies of AONs in (pre)clinical development for DMD. PMID:27612288

  2. Two genetic determinants acquired late in Mus evolution regulate the inclusion of exon 5, which alters mouse APOBEC3 translation efficiency.

    Directory of Open Access Journals (Sweden)

    Jun Li

    2012-01-01

    Full Text Available Mouse apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like editing complex 3 (mA3, an intracellular antiviral factor, has 2 allelic variations that are linked with different susceptibilities to beta- and gammaretrovirus infections among various mouse strains. In virus-resistant C57BL/6 (B6 mice, mA3 transcripts are more abundant than those in susceptible BALB/c mice both in the spleen and bone marrow. These strains of mice also express mA3 transcripts with different splicing patterns: B6 mice preferentially express exon 5-deficient (Δ5 mA3 mRNA, while BALB/c mice produce exon 5-containing full-length mA3 mRNA as the major transcript. Although the protein product of the Δ5 mRNA exerts stronger antiretroviral activities than the full-length protein, how exon 5 affects mA3 antiviral activity, as well as the genetic mechanisms regulating exon 5 inclusion into the mA3 transcripts, remains largely uncharacterized. Here we show that mA3 exon 5 is indeed a functional element that influences protein synthesis at a post-transcriptional level. We further employed in vitro splicing assays using genomic DNA clones to identify two critical polymorphisms affecting the inclusion of exon 5 into mA3 transcripts: the number of TCCT repeats upstream of exon 5 and the single nucleotide polymorphism within exon 5 located 12 bases upstream of the exon 5/intron 5 boundary. Distribution of the above polymorphisms among different Mus species indicates that the inclusion of exon 5 into mA3 mRNA is a relatively recent event in the evolution of mice. The widespread geographic distribution of this exon 5-including genetic variant suggests that in some Mus populations the cost of maintaining an effective but mutagenic enzyme may outweigh its antiviral function.

  3. Polymorphism and haplotype analyses of swine leukocyte antigen DQA exons 2, 3, 4, and their associations with piglet diarrhea in Chinese native pig.

    Science.gov (United States)

    Huang, X Y; Yang, Q L; Yuan, J H; Gun, S B

    2015-09-08

    In this study, 290 Chinese native Yantai black pig piglets were investigated to identify gene polymorphisms, for haplotype reconstruction, and to determine the association between piglet diarrhea and swine leukocyte antigen (SLA) class II DQA exons 2, 3, and 4 by polymerase chain reaction-single stranded conformational polymorphism and cloning sequencing. The results showed that the 5, 8, and 7 genotypes were identified from SLA-DQA exon 2, 3, and 4, respectively, based on the single-stranded conformational polymorphism banding patterns and found a novel allele D in exon 2 and 2 novel mutational sites of allele C (c.4828T>C) and allele F (c.4617T>C) in exon 3. Polymorphism information content testing showed that exon 2 was moderately polymorphic and that exons-3 and -4 loci were highly polymorphic. The piglet diarrhea scores for genotypes AB (1.40 ± 0.14) and AC (1.54 ± 0.17) in exon 2, AA (1.22 ± 0.32), BC (1.72 ± 0.13), DD (1.67 ± 0.35), and CF (1.22 ± 0.45) in exon 3, and AD (2.35 ± 0.25) in exon 4 were significantly higher than those for the other genotypes (P ≤ 0.05) in DQA exons. There were 14 reconstructed haplotypes in the 3 exons from 290 individuals and Hap12 may be the diarrhea-resistant gene. Haplotype distribution was extremely uneven, and the SLA-DQA gene showed genetic linkage. In this study, we identified molecular genetic markers and provided a theoretical foundation for future pig anti-disease resistance breeding.

  4. Identification of POMC exonic variants associated with substance dependence and body mass index.

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    Fan Wang

    Full Text Available BACKGROUND: Risk of substance dependence (SD and obesity has been linked to the function of melanocortin peptides encoded by the proopiomelanocortin gene (POMC. METHODS AND RESULTS: POMC exons were Sanger sequenced in 280 African Americans (AAs and 308 European Americans (EAs. Among them, 311 (167 AAs and 114 EAs were affected with substance (alcohol, cocaine, opioid and/or marijuana dependence and 277 (113 AAs and164 EAs were screened controls. We identified 23 variants, including two common polymorphisms (rs10654394 and rs1042571 and 21 rare variants; 12 of which were novel. We used logistic regression to analyze the association between the two common variants and SD or body mass index (BMI, with sex, age, and ancestry proportion as covariates. The common variant rs1042571 in the 3'UTR was significantly associated with BMI in EAs (Overweight: P(adj = 0.005; Obese: P(adj = 0.018; Overweight+Obese: P(adj = 0.002 but not in AAs. The common variant, rs10654394, was not associated with BMI and neither common variant was associated with SD in either population. To evaluate the association between the rare variants and SD or BMI, we collapsed rare variants and tested their prevalence using Fisher's exact test. In AAs, rare variants were nominally associated with SD overall and with specific SD traits (SD: P(FET,1df = 0.026; alcohol dependence: P(FET,1df = 0.027; cocaine dependence: P(FET,1df = 0.007; marijuana dependence: P(FET,1df = 0.050 (the P-value from cocaine dependence analysis survived Bonferroni correction. There was no such effect in EAs. Although the frequency of the rare variants did not differ significantly between the normal-weight group and the overweight or obese group in either population, certain rare exonic variants occurred only in overweight or obese subjects without SD. CONCLUSION: These findings suggest that POMC exonic variants may influence risk for both SD and elevated BMI, in a population-specific manner. However, common

  5. Identifying alternative hyper-splicing signatures in MG-thymoma by exon arrays.

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    Lilach Soreq

    Full Text Available BACKGROUND: The vast majority of human genes (>70% are alternatively spliced. Although alternative pre-mRNA processing is modified in multiple tumors, alternative hyper-splicing signatures specific to particular tumor types are still lacking. Here, we report the use of Affymetrix Human Exon Arrays to spot hyper-splicing events characteristic of myasthenia gravis (MG-thymoma, thymic tumors which develop in patients with MG and discriminate them from colon cancer changes. METHODOLOGY/PRINCIPAL FINDINGS: We combined GO term to parent threshold-based and threshold-independent ad-hoc functional statistics with in-depth analysis of key modified transcripts to highlight various exon-specific changes. These denote alternative splicing in MG-thymoma tumors compared to healthy human thymus and to in-house and Affymetrix datasets from colon cancer and healthy tissues. By using both global and specific, term-to-parent Gene Ontology (GO statistical comparisons, our functional integrative ad-hoc method allowed the detection of disease-relevant splicing events. CONCLUSIONS/SIGNIFICANCE: Hyper-spliced transcripts spanned several categories, including the tumorogenic ERBB4 tyrosine kinase receptor and the connective tissue growth factor CTGF, as well as the immune function-related histocompatibility gene HLA-DRB1 and interleukin (IL19, two muscle-specific collagens and one myosin heavy chain gene; intriguingly, a putative new exon was discovered in the MG-involved acetylcholinesterase ACHE gene. Corresponding changes in spliceosome composition were indicated by co-decreases in the splicing factors ASF/SF(2 and SC35. Parallel tumor-associated changes occurred in colon cancer as well, but the majority of the apparent hyper-splicing events were particular to MG-thymoma and could be validated by Fluorescent In-Situ Hybridization (FISH, Reverse Transcription-Polymerase Chain Reaction (RT-PCR and mass spectrometry (MS followed by peptide sequencing. Our findings

  6. Chimeric snRNA molecules carrying antisense sequences against the splice junctions of exon 51 of the dystrophin pre-mRNA induce exon skipping and restoration of a dystrophin synthesis in Δ48-50 DMD cells

    Science.gov (United States)

    De Angelis, Fernanda Gabriella; Sthandier, Olga; Berarducci, Barbara; Toso, Silvia; Galluzzi, Giuliana; Ricci, Enzo; Cossu, Giulio; Bozzoni, Irene

    2002-01-01

    Deletions and point mutations in the dystrophin gene cause either the severe progressive myopathy Duchenne muscular dystrophy (DMD) or the milder Becker muscular dystrophy, depending on whether the translational reading frame is lost or maintained. Because internal in-frame deletions in the protein produce only mild myopathic symptoms, it should be possible, by preventing the inclusion of specific mutated exon(s) in the mature dystrophin mRNA, to restore a partially corrected phenotype. Such control has been previously accomplished by the use of synthetic oligonucleotides; nevertheless, a significant drawback to this approach is caused by the fact that oligonucleotides would require periodic administrations. To circumvent this problem, we have produced several constructs able to express in vivo, in a stable fashion, large amounts of chimeric RNAs containing antisense sequences. In this paper we show that antisense molecules against exon 51 splice junctions are able to direct skipping of this exon in the human DMD deletion 48–50 and to rescue dystrophin synthesis. We also show that the highest skipping activity was found when antisense constructs against the 5′ and 3′ splice sites are coexpressed in the same cell. PMID:12077324

  7. Mapping Human Pluripotent-to-Cardiomyocyte Differentiation: Methylomes, Transcriptomes, and Exon DNA Methylation “Memories”

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    Joshua D. Tompkins

    2016-02-01

    Full Text Available The directed differentiation of human cardiomyocytes (CMs from pluripotent cells provides an invaluable model for understanding mechanisms of cell fate determination and offers considerable promise in cardiac regenerative medicine. Here, we utilize a human embryonic stem cell suspension bank, produced according to a good manufacturing practice, to generate CMs using a fully defined and small molecule-based differentiation strategy. Primitive and cardiac mesoderm purification was used to remove non-committing and multi-lineage populations and this significantly aided the identification of key transcription factors, lncRNAs, and essential signaling pathways that define cardiomyogenesis. Global methylation profiles reflect CM development and we report on CM exon DNA methylation “memories” persisting beyond transcription repression and marking the expression history of numerous developmentally regulated genes, especially transcription factors.

  8. Tandem duplication of DMD exon 18 associated with epilepsy, macroglossia, and endocrinologic abnormalities.

    Science.gov (United States)

    Weiss, Claudia; Jakubiczka, Sibylle; Huebner, Angela; Klopocki, Eva; Kress, Wolfram; Voit, Thomas; Hübner, Christoph; Schuelke, Markus

    2007-03-01

    We describe a patient with Duchenne muscular dystrophy (DMD) who additionally suffered from intractable seizures, severe mental retardation, and a marked macroglossia. He also had endocrinologic abnormalities consisting of growth hormone deficiency, delayed puberty, and adrenal hypoplasia. We detected a duplication of DMD exon 18 and flanking introns that caused a frame-shift and was not removed by corrective splicing. A coincident mutation in the FKRP gene was excluded by direct sequencing. Complex DNA rearrangements, deletions, and duplications >100 kb were excluded through microarray-comparative genomic hybridization (CGH), although we were not able to exclude a second coincident mutation with certainty. In conclusion, we present a case of DMD that conflicts with current understanding of genotype-phenotype relations and discuss putative pathogenetic mechanisms for this uncommon phenotype.

  9. Exonic deletion of OPHN1 resulting in seizures, intellectual disability, and brain malformations

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    Larson A

    2014-07-01

    Full Text Available Austin Larson,1 Jamie LeRoux,2 Ellen Roy Elias11Department of Pediatrics, University of Colorado Denver Anschutz Medical Campus, Aurora, CO, USA; 2Colorado Genetics Laboratory, Denver, CO, USAAbstract: We report the case of a 9-year-old boy with autism, intellectual disability, and complex partial seizures as well as cerebellar vermian hypoplasia, caudate nucleus hypoplasia, and ventriculomegaly. He was found to have a deletion within the oligophrenin 1 gene (OPHN1, affecting exons 2–5. OPHN1 mutations result in a rare but well-characterized syndrome of neuroanatomical anomalies, epilepsy, and intellectual disability. This is a novel mutation in OPHN1 that adds to the spectrum of pathogenic variants of the gene. Additionally, the case illustrates the significant benefit that patients and families can derive from a definitive genetic diagnosis, even in the absence of direct therapeutic interventions.Keywords: X-linked intellectual disability, autism, cerebellar hypoplasia, chromosomal microarray, oligophrenin 1

  10. The exon junction complex as a node of post-transcriptional networks.

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    Le Hir, Hervé; Saulière, Jérôme; Wang, Zhen

    2016-01-01

    The exon junction complex (EJC) is deposited onto mRNAs following splicing and adopts a unique structure, which can both stably bind to mRNAs and function as an anchor for diverse processing factors. Recent findings revealed that in addition to its established roles in nonsense-mediated mRNA decay, the EJC is involved in mRNA splicing, transport and translation. While structural studies have shed light on EJC assembly, transcriptome-wide analyses revealed differential EJC loading at spliced junctions. Thus, the EJC functions as a node of post-transcriptional gene expression networks, the importance of which is being revealed by the discovery of increasing numbers of EJC-related disorders.

  11. Becker muscular dystrophy with widespread muscle hypertrophy and a non-sense mutation of exon 2.

    Science.gov (United States)

    Witting, N; Duno, M; Vissing, J

    2013-01-01

    Becker muscular dystrophy features progressive proximal weakness, wasting and often focal hypertrophy. We present a patient with pain and cramps from adolescence. Widespread muscle hypertrophy, preserved muscle strength and a 10-20-fold raised CPK were noted. Muscle biopsy was dystrophic, and Western blot showed a 95% reduction of dystrophin levels. Genetic analyses revealed a non-sense mutation in exon 2 of the dystrophin gene. This mutation is predicted to result in a Duchenne phenotype, but resulted in a mild Becker muscular dystrophy with widespread muscle hypertrophy. We suggest that this unusual phenotype is caused by translation re-initiation downstream from the mutation site. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. WNT10A exonic variant increases the risk of keratoconus by decreasing corneal thickness.

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    Cuellar-Partida, Gabriel; Springelkamp, Henriët; Lucas, Sionne E M; Yazar, Seyhan; Hewitt, Alex W; Iglesias, Adriana I; Montgomery, Grant W; Martin, Nicholas G; Pennell, Craig E; van Leeuwen, Elisabeth M; Verhoeven, Virginie J M; Hofman, Albert; Uitterlinden, André G; Ramdas, Wishal D; Wolfs, Roger C W; Vingerling, Johannes R; Brown, Matthew A; Mills, Richard A; Craig, Jamie E; Klaver, Caroline C W; van Duijn, Cornelia M; Burdon, Kathryn P; MacGregor, Stuart; Mackey, David A

    2015-09-01

    Keratoconus is a degenerative eye condition which results from thinning of the cornea and causes vision distortion. Treatments such as ultraviolet (UV) cross-linking have proved effective for management of keratoconus when performed in early stages of the disease. The central corneal thickness (CCT) is a highly heritable endophenotype of keratoconus, and it is estimated that up to 95% of its phenotypic variance is due to genetics. Genome-wide association efforts of CCT have identified common variants (i.e. minor allele frequency (MAF) >5%). However, these studies typically ignore the large set of exonic variants whose MAF is usually low. In this study, we performed a CCT exome-wide association analysis in a sample of 1029 individuals from a population-based study in Western Australia. We identified a genome-wide significant exonic variant rs121908120 (P = 6.63 × 10(-10)) in WNT10A. This gene is 437 kb from a gene previously associated with CCT (USP37). We showed in a conditional analysis that the WNT10A variant completely accounts for the signal previously seen at USP37. We replicated our finding in independent samples from the Brisbane Adolescent Twin Study, Twin Eye Study in Tasmania and the Rotterdam Study. Further, we genotyped rs121908120 in 621 keratoconus cases and compared the frequency to a sample of 1680 unscreened controls from the Queensland Twin Registry. We found that rs121908120 increases the risk of keratoconus two times (odds ratio 2.03, P = 5.41 × 10(-5)). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Analysis of MEFV exon methylation and expression patterns in familial Mediterranean fever

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    Ozdogan Huri

    2011-08-01

    Full Text Available Abstract Background MEFV mutations and decreased expression level of the gene are related to FMF pathology. DNA methylation at CpG islands is a well-known mechanism for transcriptional silencing. MEFV has a CpG island, spanning a part of the first intron and the whole of the second exon of the gene covering 998 bp region. Here, we tested the hypothesis that the MEFV transcript level in FMF patients correlates with its methylation level, and methylation, by allowing transcription silencing, has a role in FMF ethiopathogenesis. Methods The study group was composed of pediatric FMF patients (N = 51 and age-gender matched healthy controls (N = 21. The relative expression level of MEFV was assessed via quantitative real-time PCR (qRT-PCR and bisulfite sequencing (BS was performed to analyse the methylation level quantitatively. Results MEFV expression in FMF patients were decreased compared to healthy controls (P = 0.031. Methylation level of exon 2 of MEFV was found to be slightly higher in FMF patients compared to healthy controls (76% versus 74% (P = 0.049. The expression level of the MEFV was negatively correlated with the methylation level of the CpG island in both FMF and healthy controls groups (cor = -0.29, P = 0.041 but more so in the FMF only group (cor = -0.36, P = 0.035. Conclusions In this study, the relation between reduced MEFV expression level and FMF was confirmed. Observed slight increase in methylation in FMF patients, and correlation of methylation with expression might be indicative of its role in FMF, however a larger dataset is needed to confirm our preliminary findings.

  14. Complete exon sequencing of all known Usher syndrome genes greatly improves molecular diagnosis

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    Lacombe Didier

    2011-05-01

    Full Text Available Abstract Background Usher syndrome (USH combines sensorineural deafness with blindness. It is inherited in an autosomal recessive mode. Early diagnosis is critical for adapted educational and patient management choices, and for genetic counseling. To date, nine causative genes have been identified for the three clinical subtypes (USH1, USH2 and USH3. Current diagnostic strategies make use of a genotyping microarray that is based on the previously reported mutations. The purpose of this study was to design a more accurate molecular diagnosis tool. Methods We sequenced the 366 coding exons and flanking regions of the nine known USH genes, in 54 USH patients (27 USH1, 21 USH2 and 6 USH3. Results Biallelic mutations were detected in 39 patients (72% and monoallelic mutations in an additional 10 patients (18.5%. In addition to biallelic mutations in one of the USH genes, presumably pathogenic mutations in another USH gene were detected in seven patients (13%, and another patient carried monoallelic mutations in three different USH genes. Notably, none of the USH3 patients carried detectable mutations in the only known USH3 gene, whereas they all carried mutations in USH2 genes. Most importantly, the currently used microarray would have detected only 30 of the 81 different mutations that we found, of which 39 (48% were novel. Conclusions Based on these results, complete exon sequencing of the currently known USH genes stands as a definite improvement for molecular diagnosis of this disease, which is of utmost importance in the perspective of gene therapy.

  15. The differential roles of Slit2-exon 15 splicing variants in angiogenesis and HUVEC permeability.

    Science.gov (United States)

    Yang, Yun-Chiu; Chen, Pei-Ni; Wang, Siou-Yu; Liao, Chen-Yi; Lin, Yu-Ying; Sun, Shih-Rhong; Chiu, Chun-Ling; Hsieh, Yih-Shou; Shieh, Jia-Ching; Chang, Jinghua Tsai

    2015-07-01

    Slit2, a secreted glycoprotein, is down-regulated in many cancers. Slit2/Robo signaling pathway plays an important, but controversial, role in angiogenesis. We identified splicing variants of Slit2 at exon 15, Slit2-WT and Slit2-ΔE15, with differential effects on proliferation and invasive capability of lung cancer cells. The aim of this study was to elucidate the differential roles of these exon 15 splicing variants in angiogenesis. Our results revealed that both Slit2-WT and Slit2-ΔE15 inhibit motility of human umbilical vein endothelial cells (HUVECs). The conditioned medium (CM) collected from CL1-5/VC or CL1-5/Slit2-WT lung adenocarcinoma cells blocked HUVEC tube formation and angiogenesis on chorioallantoic membrane (CAM) assay when compared with untreated HUVECs and CAM, respectively. However, CM of CL1-5/Slit2-ΔE15 restored the quality of tubes and the size of vessels. Although both Slit2-WT and Slit2-ΔE15 inhibited permeability induced by CM of cancer cells, Slit2-ΔE15 exhibited stronger effect. These results suggested that Slit2-ΔE15 plays important roles in normalization of blood vessels by enhancing tube quality and tightening endothelial cells, while Slit2-WT only enhances tightening of endothelial cells. It appears that Robo4 is responsible for Slit2 isoform-mediated inhibition of permeability, while neither Robo1 nor Robo4 is required for Slit2-ΔE15-enhanced tube quality. The results of this study suggest that Slit2-ΔE15 splicing form is a promising molecule for normalizing blood vessels around a tumor, which, in turn, may increase efficacy of chemotherapy and radiotherapy.

  16. Genetic variation in exon 5 of troponin - I gene in hypertrophic cardiomyopathy cases

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    Annapurna S

    2007-01-01

    Full Text Available Background: Cardiomyopathies are a heterogeneous group of heart muscle disorders and are classified as 1 Hypertrophic Cardiomyopathy (HCM 2 Dilated cardiomyopathy (DCM 3 Restrictive cardiomyopathy (RCM and 4 Arrhythmogenic right ventricular dysplasia (ARVD as per WHO classification, of which HCM and DCM are common. HCM is a complex but relatively common form of inherited heart muscle disease with prevalence of 1 in 500 individuals and is commonly associated with sarcomeric gene mutations. Cardiac muscle troponin I (TNNI-3 is one such sarcomeric protein and is a subunit of the thin filament-associated troponin-tropomyosin complex involved in calcium regulation of skeletal and cardiac muscle contraction. Mutations in this gene were found to be associated with a history of sudden cardiac death in HCM patients. Aim: Therefore the present study aims to identify for mutations associated with troponin I gene in a set of HCM patients from Indian population. Materials and Methods: Mutational analyses of 92 HCM cases were carried out following PCR based SSCP analysis. Results: The study revealed band pattern variation in 3 cases from a group of 92 HCM patients. This band pattern variation, on sequencing revealed base changes, one at nt 2560 with G>T transversion in exon-5 region with a wobble and others at nt 2479 and nt 2478 with G>C and C>G transversions in the intronic region upstream of the exon 5 on sequencing. Further analysis showed that one of the probands showed apical form of hypertrophy, two others showing asymmetric septal hypertrophy. Two of these probands showed family history of the condition. Conclusions: Hence, the study supports earlier reports of involvement of TNNI-3 in the causation of apical and asymmetrical forms of hypertrophy.

  17. An exonic insertion within Tex14 gene causes spermatogenic arrest in pigs

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    Sironen Anu

    2011-12-01

    Full Text Available Abstract Background Male infertility is an increasing problem in all domestic species including man. Localization and identification of genes involved in defects causing male infertility provide valuable information of specific events in sperm development. Sperm development is a complex process, where diploid spermatogonia develop into haploid, highly specialized spermatozoa. Correct expression and function of various genes and their protein products are required for production of fertile sperm. We have identified an infertility defect in Finnish Yorkshire boars caused by spermatogenic arrest. The aim of this study was to locate the disease associated region using genome wide screen with the PorcineSNP60 Beadchip and identify the causal mutation by candidate gene approach. Results In the Finnish Yorkshire pig population the spermatogenic arrest (SA defect appears to be of genetic origin and causes severe degeneration of germ cells and total absence of spermatozoa. Genome wide scan with the PorcineSNP60 Beadchip localized the SA defect to porcine chromosome 12 in a 2 Mbp region. Sequencing of a candidate gene Tex14 revealed a 51 bp insertion within exon 27, which caused differential splicing of the exon and created a premature translation stop codon. The expression of Tex14 was markedly down regulated in the testis of a SA affected boar compared to control boars and no protein product was identified by Western blotting. The SA insertion sequence was also found within intron 27 in all analyzed animals, thus the insertion appears to be a possible duplication event. Conclusion In this study we report the identification of a causal mutation for infertility caused by spermatogenic arrest at an early meiotic phase. Our results highlight the role of TEX14 specifically in spermatogenesis and the importance of specific genomic remodeling events as causes for inherited defects.

  18. Evidence for widespread exonic small RNAs in the glaucophyte alga Cyanophora paradoxa.

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    Jeferson Gross

    Full Text Available RNAi (RNA interference relies on the production of small RNAs (sRNAs from double-stranded RNA and comprises a major pathway in eukaryotes to restrict the propagation of selfish genetic elements. Amplification of the initial RNAi signal by generation of multiple secondary sRNAs from a targeted mRNA is catalyzed by RNA-dependent RNA polymerases (RdRPs. This phenomenon is known as transitivity and is particularly important in plants to limit the spread of viruses. Here we describe, using a genome-wide approach, the distribution of sRNAs in the glaucophyte alga Cyanophora paradoxa. C. paradoxa is a member of the supergroup Plantae (also known as Archaeplastida that includes red algae, green algae, and plants. The ancient (>1 billion years ago split of glaucophytes within Plantae suggests that C. paradoxa may be a useful model to learn about the early evolution of RNAi in the supergroup that ultimately gave rise to plants. Using next-generation sequencing and bioinformatic analyses we find that sRNAs in C. paradoxa are preferentially associated with mRNAs, including a large number of transcripts that encode proteins arising from different functional categories. This pattern of exonic sRNAs appears to be a general trend that affects a large fraction of mRNAs in the cell. In several cases we observe that sRNAs have a bias for a specific strand of the mRNA, including many instances of antisense predominance. The genome of C. paradoxa encodes four sequences that are homologous to RdRPs in Arabidopsis thaliana. We discuss the possibility that exonic sRNAs in the glaucophyte may be secondarily derived from mRNAs by the action of RdRPs. If this hypothesis is confirmed, then transitivity may have had an ancient origin in Plantae.

  19. Missense Mutations in Exons 18–24 of EGFR in Hepatocellular Carcinoma Tissues

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    Ravat Panvichian

    2015-01-01

    Full Text Available Epidermal growth factor receptor (EGFR, a transmembrane tyrosine kinase receptor, plays important roles in various cancers. In nonsmall cell lung cancer (NSCLC, EGFR mutations cluster around the ATP-binding pocket (exons 18–21 and some of these mutations activate the kinase and induce an increased sensitivity to EGFR-tyrosine kinase inhibitors. Nevertheless, data of EGFR mutations in HCC are limited. In this study, we investigated EGFR expression by immunohistochemistry and EGFR mutations (exons 18–24 by PCR cloning and sequencing. EGFR overexpression in HCC and matched nontumor tissues were detected in 13/40 (32.5% and 10/35 (28.6%, respectively. Moreover, missense and silent mutations were detected in 13/33 (39.4% and 11/33 (33.3% of HCC tissues, respectively. The thirteen different missense mutations were p.L730P, p.V742I, p.K757E, p.I780T, p.N808S, p.R831C, p.V851A, p.V897A, p.S912P, p.P937L, p.T940A, p.M947V, and p.M947T. We also found already known SNP, p.Q787Q (CAG>CAA, in 13/33 (39.4% of HCC tissues. However, no significant association was detected between EGFR mutations and EGFR overexpression, tissue, age, sex, tumor size, AFP, HBsAg, TP53, and Ki-67. Further investigation is warranted to validate the frequency and activity of these missense mutations, as well as their roles in HCC tumorigenesis and in EGFR-targeted therapy.

  20. Finding exonic islands in a sea of non-coding sequence: splicing related constraints on protein composition and evolution are common in intron-rich genomes.

    NARCIS (Netherlands)

    Warnecke, T.; Parmley, J.L.; Hurst, L.D.

    2008-01-01

    BACKGROUND: In mammals, splice-regulatory domains impose marked trends on the relative abundance of certain amino acids near exon-intron boundaries. Is this a mammalian particularity or symptomatic of exonic splicing regulation across taxa? Are such trends more common in species that a priori have a

  1. Evolution of alternative splicing regulation: changes in predicted exonic splicing regulators are not associated with changes in alternative splicing levels in primates

    DEFF Research Database (Denmark)

    Irimia, Manuel; Rukov, Jakob Lewin; Roy, Scott William

    2009-01-01

    and changes in alternative splicing levels. This observation holds across different ESR exon positions, exon lengths, and 5' splice site strengths. We suggest that this lack of association is mainly due to the great importance of context for ESR functionality: many ESR-like motifs in primates may have little...

  2. NUCLEOTIDE-SEQUENCE OF THE LAST EXON OF THE GENE FOR HUMAN CYTOCHROME-C-OXIDASE SUBUNIT-VIB AND ITS FLANKING REGIONS

    NARCIS (Netherlands)

    TAANMAN, JW; SCHRAGE, C; BOKMA, E; REUVEKAMP, P; AGSTERIBBE, E; DEVRIES, H

    1991-01-01

    A human genomic clone encompassing the last exon of the gene for cytochrome c oxidase subunit VIb and a human genomic clone containing the most distal end of this gene were characterized. The last exon of the gene codes for the 17 C-terminal amino acid residues of the subunit and the 3' noncoding re

  3. The Ds1 Transposon Provides Messages That Yield Unique Profiles of Protein Isoforms and Acts Synergistically With Ds to Enrich Proteome Complexity via Exonization.

    Science.gov (United States)

    Charng, Yuh-Chyang; Hsu, Lung-Hsin; Liu, Li-Yu Daisy

    2017-01-01

    In exonization events, Ds1 may provide donor and/or acceptor sites for splicing after inserting into genes and be incorporated into new transcripts with new exon(s). In this study, the protein variants of Ds1 exonization yielding additional functional profile(s) were studied. Unlike Ds exonization, which creates new profiles mostly by incorporating flanking intron sequences with the Ds message, Ds1 exonization additionally creates new profiles through the presence or absence of Ds1 messages. The number of unique functional profiles harboring Ds1 messages is 1.3-fold more than that of functional profiles without Ds1 messages. The highly similar 11 protein isoforms at a single insertion site also contribute to proteome complexity enrichment by exclusively creating new profiles. Particularly, Ds1 exonization produces 459 unique profiles, of which 129 cannot be built by Ds. We thus conclude that Ds and Ds1 are independent but synergistic in their capacity to enrich proteome complexity through exonization.

  4. KIT exon 11 codon 557/558 deletion/insertion mutations define a subset of gastrointestinal stromal tumors with malignant potential

    Institute of Scientific and Technical Information of China (English)

    Katerina Kontogianni-Katsarou; Euthimios Dimitriadis; Constantina Lariou; Evi Kairi-Vassilatou; Nikolaos Pandis; Agatha Kondi-Paphiti

    2008-01-01

    AIM: To study the association of the frequency and pattern of KIT and PDGFRA mutations and dinicopathological factors in a group of patients with gastrointestinal stromal tumors (GIST).METHODS: Thirty patients with GIST were examined. Exons 9, 11,13, and 17 of the KIT and exons 12 and 18 of the PDGFRA gene were analyzed for the presence of mutations by PCR amplification and direct sequencing.RESULTS: KIT or PDGFRA mutations were detected in 21 of the 30 patients (70%). Sixteen patients had mutations within KIT exon 11, three within KIT exon 9, and two within PDGFRA exon 18. GISTs with KIT exon 9 mutations were predominantly located in the small intestine, showed a spindle cell phenotype, and were assessed as potentially malignant. GISTs with KIT exon 11 mutations were located in the stomach and intestine, showed mainly a spindle cell phenotype, and were scored as potentially malignant (P < 0.05). Tumors with KIT exon 11 codon 557/558 deletion/insertion mutations were found to be associated with a potentially malignant clinical behaviour (P < 0.003). GISTs with PDGFRA mutations located in stomach showed a mixed cell phenotype and were classified as of very low or low moderate malignant potential.CONCLUSION: Determination of KIT and PDGFRA mutations should be additional parameters for the better prediction of GISTs clinical behaviour. Tumors with deletion/insertion mutations affecting codons 557/558 of the KIT gene seem to represent a distinct subset of malignant GISTs.

  5. Single nucleotide polymorphism mining and nucleotide sequence analysis of Mx1 gene in exonic regions of Japanese quail

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    Diwesh Kumar Niraj

    2015-12-01

    Full Text Available Aim: An attempt has been made to study the Myxovirus resistant (Mx1 gene polymorphism in Japanese quail. Materials and Methods: In the present, investigation four fragments viz. Fragment I of 185 bp (Exon 3 region, Fragment II of 148 bp (Exon 5 region, Fragment III of 161 bp (Exon 7 region, and Fragment IV of 176 bp (Exon 13 region of Mx1 gene were amplified and screened for polymorphism by polymerase chain reaction-single-strand conformation polymorphism technique in 170 Japanese quail birds. Results: Out of the four fragments, one fragment (Fragment II was found to be polymorphic. Remaining three fragments (Fragment I, III, and IV were found to be monomorphic which was confirmed by custom sequencing. Overall nucleotide sequence analysis of Mx1 gene of Japanese quail showed 100% homology with common quail and more than 80% homology with reported sequence of chicken breeds. Conclusion: The Mx1 gene is mostly conserved in Japanese quail. There is an urgent need of comprehensive analysis of other regions of Mx1 gene along with its possible association with the traits of economic importance in Japanese quail.

  6. A Targeted Oligonucleotide Enhancer of SMN2 Exon 7 Splicing Forms Competing Quadruplex and Protein Complexes in Functional Conditions

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    Lindsay D. Smith

    2014-10-01

    Full Text Available The use of oligonucleotides to activate the splicing of selected exons is limited by a poor understanding of the mechanisms affected. A targeted bifunctional oligonucleotide enhancer of splicing (TOES anneals to SMN2 exon 7 and carries an exonic splicing enhancer (ESE sequence. We show that it stimulates splicing specifically of intron 6 in the presence of repressing sequences in intron 7. Complementarity to the 5′ end of exon 7 increases U2AF65 binding, but the ESE sequence is required for efficient recruitment of U2 snRNP. The ESE forms at least three coexisting discrete states: a quadruplex, a complex containing only hnRNP F/H, and a complex enriched in the activator SRSF1. Neither hnRNP H nor quadruplex formation contributes to ESE activity. The results suggest that splicing limited by weak signals can be rescued by rapid exchange of TOES oligonucleotides in various complexes and raise the possibility that SR proteins associate transiently with ESEs.

  7. A conserved alternative splicing event in plants reveals an ancient exonization of 5S rRNA that regulates TFIIIA.

    Science.gov (United States)

    Barbazuk, W Brad

    2010-01-01

    Uncovering conserved alternative splicing (AS) events can identify AS events that perform important functions. This is especially useful for identifying premature stop codon containing (PTC) AS isoforms that may regulate protein expression by being targets for nonsense mediated decay. This report discusses the identification of a PTC containing splice isoform of the TFIIIA gene that is highly conserved in land plants. TFIIIA is essential for RNA Polymerase III-based transcription of 5S rRNA in eukaryotes. Two independent groups have determined that the PTC containing alternative exon is ultraconserved and is coupled with nonsense-mediated mRNA decay. The alternative exon appears to have been derived by the exonization of 5S ribosomal RNA (5S rRNA) within the gene of its own transcription regulator, TFIIIA. This provides the first evidence of ancient exaptation of 5S rRNA in plants, suggesting a novel gene regulation model mediated by the AS of an anciently exonized non-coding element.

  8. Rescue of cardiomyopathy through U7snRNA-mediated exon skipping in Mybpc3-targeted knock-in mice.

    Science.gov (United States)

    Gedicke-Hornung, Christina; Behrens-Gawlik, Verena; Reischmann, Silke; Geertz, Birgit; Stimpel, Doreen; Weinberger, Florian; Schlossarek, Saskia; Précigout, Guillaume; Braren, Ingke; Eschenhagen, Thomas; Mearini, Giulia; Lorain, Stéphanie; Voit, Thomas; Dreyfus, Patrick A; Garcia, Luis; Carrier, Lucie

    2013-07-01

    Exon skipping mediated by antisense oligoribonucleotides (AON) is a promising therapeutic approach for genetic disorders, but has not yet been evaluated for cardiac diseases. We investigated the feasibility and efficacy of viral-mediated AON transfer in a Mybpc3-targeted knock-in (KI) mouse model of hypertrophic cardiomyopathy (HCM). KI mice carry a homozygous G>A transition in exon 6, which results in three different aberrant mRNAs. We identified an alternative variant (Var-4) deleted of exons 5-6 in wild-type and KI mice. To enhance its expression and suppress aberrant mRNAs we designed AON-5 and AON-6 that mask splicing enhancer motifs in exons 5 and 6. AONs were inserted into modified U7 small nuclear RNA and packaged in adeno-associated virus (AAV-U7-AON-5+6). Transduction of cardiac myocytes or systemic administration of AAV-U7-AON-5+6 increased Var-4 mRNA/protein levels and reduced aberrant mRNAs. Injection of newborn KI mice abolished cardiac dysfunction and prevented left ventricular hypertrophy. Although the therapeutic effect was transient and therefore requires optimization to be maintained over an extended period, this proof-of-concept study paves the way towards a causal therapy of HCM.

  9. Structure of the exon junction core complex with a trapped DEAD-box ATPase bound to RNA

    DEFF Research Database (Denmark)

    Andersen, Christian Brix Folsted; Ballut, Lionel; Johansen, Jesper Sanderhoff;

    2006-01-01

    In higher eukaryotes, a multiprotein exon junction complex is deposited on spliced messenger RNAs. The complex is organized around a stable core, which serves as a binding platform for numerous factors that influence messenger RNA function. Here, we present the crystal structure of a tetrameric e...

  10. Identification and differentiation of Candida parapsilosis complex species by use of exon-primed intron-crossing PCR.

    Science.gov (United States)

    Feng, Xiaobo; Wu, Zengbin; Ling, Bo; Pan, Shuming; Liao, Wanqing; Pan, Weihua; Yao, Zhirong

    2014-05-01

    The Candida parapsilosis complex is composed of Candida parapsilosis sensu stricto, Candida orthopsilosis, Candida metapsilosis, and the closely related species Lodderomyces elongisporus. An exon-primed intron-crossing PCR assay was developed here to distinguish the members of the species complex on the basis of the distinct sizes of amplicons, and Candida orthopsilosis and Candida metapsilosis were further discriminated by restriction enzyme analysis.

  11. A highly sensitive quantitative real-time PCR assay for determination of mutant JAK2 exon 12 allele burden.

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    Lasse Kjær

    Full Text Available Mutations in the Janus kinase 2 (JAK2 gene have become an important identifier for the Philadelphia-chromosome negative chronic myeloproliferative neoplasms. In contrast to the JAK2V617F mutation, the large number of JAK2 exon 12 mutations has challenged the development of quantitative assays. We present a highly sensitive real-time quantitative PCR assay for determination of the mutant allele burden of JAK2 exon 12 mutations. In combination with high resolution melting analysis and sequencing the assay identified six patients carrying previously described JAK2 exon 12 mutations and one novel mutation. Two patients were homozygous with a high mutant allele burden, whereas one of the heterozygous patients had a very low mutant allele burden. The allele burden in the peripheral blood resembled that of the bone marrow, except for the patient with low allele burden. Myeloid and lymphoid cell populations were isolated by cell sorting and quantitative PCR revealed similar mutant allele burdens in CD16+ granulocytes and peripheral blood. The mutations were also detected in B-lymphocytes in half of the patients at a low allele burden. In conclusion, our highly sensitive assay provides an important tool for quantitative monitoring of the mutant allele burden and accordingly also for determining the impact of treatment with interferon-α-2, shown to induce molecular remission in JAK2V617F-positive patients, which may be a future treatment option for JAK2 exon 12-positive patients as well.

  12. Activation and repression functions of an SR splicing regulator depend on exonic versus intronic-binding position.

    Science.gov (United States)

    Shen, Manli; Mattox, William

    2012-01-01

    SR proteins and related factors play widespread roles in alternative pre-mRNA splicing and are known to promote splice site recognition through their Arg-Ser-rich effector domains. However, binding of SR regulators to some targets results in repression of splice sites through a distinct mechanism. Here, we investigate how activated and repressed targets of the Drosophila SR regulator Transformer2 elicit its differing effects on splicing. We find that, like activation, repression affects early steps in the recognition of splice sites and spliceosome assembly. Repositioning of regulatory elements reveals that Tra2 complexes that normally repress splicing from intronic positions activate splicing when located in an exon. Protein tethering experiments demonstrate that this position dependence is an intrinsic property of Tra2 and further show that repression and activation are mediated by separate effector domains of this protein. When other Drosophila SR factors (SF2 and Rbp1) that activate splicing from exonic positions were tethered intronically they failed to either activate or repress splicing. Interestingly, both activities of Tra2 favor the exonic identity of the RNA sequences that encompass its binding sites. This suggests a model in which these two opposite functions act in concert to define both the position and extent of alternatively spliced exons.

  13. Disease-causing mutations in exon 11 of the medium-chain acyl-CoA dehydrogenase gene

    DEFF Research Database (Denmark)

    Andresen, B S; Jensen, T G; Bross, P

    1994-01-01

    spot. Here we describe the results from sequence analysis of exon 11 and part of the flanking introns from 36 compound heterozygous patients with MCAD deficiency. We have identified four previously unknown disease-causing mutations (M301T, S311R, R324X, and E359X) and two silent mutations in exon 11......Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the most commonly recognized defect of the mitochondrial beta-oxidation in humans. It is a potentially fatal, autosomal recessive inherited defect. Most patients with MCAD deficiency are homozygous for a single disease-causing mutation (G985......), causing a change from lysine to glutamate at position 304 (K304E) in the mature MCAD. Only seven non-G985 mutations, all of which are rare, have been reported. Because the G985 mutation and three of the non-G985 mutations are located in exon 11, it has been suggested that this exon may be a mutational hot...

  14. Alternative exon-encoding regions of Locusta migratoria muscle myosin modulate the pH dependence of ATPase activity.

    Science.gov (United States)

    Li, J; Lu, Z; He, J; Chen, Q; Wang, X; Kang, L; Li, X-D

    2016-12-01

    Whereas the vertebrate muscle myosin heavy chains (MHCs) are encoded by a family of Mhc genes, most insects examined to date contain a single Mhc gene and produce all of the different MHC isoforms by alternative RNA splicing. Here, we found that the migratory locust, Locusta migratoria, has one Mhc gene, which contains 41 exons, including five alternative exclusive exons and one differently included penultimate exon, and potentially encodes 360 MHC isoforms. From the adult L. migratoria, we identified 14 MHC isoforms (including two identical isoforms): four from flight muscle (the thorax dorsal longitudinal muscle), three from jump muscle (the hind leg extensor tibiae muscle) and seven from the abdominal intersegmental muscle. We purified myosins from flight muscle and jump muscle and characterized their motor activities. At neutral pH, the flight and the jump muscle myosins displayed similar levels of in vitro actin-gliding activity, whereas the former had a slightly higher actin-activated ATPase activity than the latter. Interestingly, the pH dependences of the actin-activated ATPase activity of these two myosins are different. Because the dominant MHC isoforms in these two muscles are identical except for the two alternative exon-encoding regions, we propose that these two alternative regions modulate the pH dependence of L. migratoria muscle myosin.

  15. Positive Darwinian selection in Vipera palaestinae phospholipase A2 genes is unexpectedly limited to the third exon.

    Science.gov (United States)

    Kordis, D; Bdolah, A; Gubensek, F

    1998-10-20

    The venom of Vipera palaestinae contains a two-component toxin, consisting of an acidic phospholipase A2 (PLA2) and a basic protein. Here we report the cloning and sequence analysis of the complete V. palaestinae PLA2 genes. Since in all Viperidae PLA2 multigene families the 5' and 3' flanking regions are highly conserved, we designed oligonucleotide primers that allow amplification of the whole PLA2 multigene family in a single step. The structural organization of both genes is the same as in the Vipera ammodytes PLA2 multigene family, there being five exons separated by four introns. Comparison of V. palaestinae PLA2 genes with other Viperidae PLA2 genes has shown that the structural organization of the genes and the nucleotide sequence of all introns and flanking regions are highly conserved, whereas the third exon clearly shows a higher number of amino acid replacements, an indication of positive Darwinian selection. The positive Darwinian selection is surprisingly limited to the third exon, in contrast to other Viperidae PLA2 genes, where it is present in all mature protein coding exons. Copyright 1998 Academic Press.

  16. Lack of association of DRD4 exon 3 VNTR genotype with reactivity to dynamic smoking cues in movies

    NARCIS (Netherlands)

    Lochbühler, K.C.; Verhagen, M.; Munafo, M.R.; Engels, R.C.M.E.

    2013-01-01

    Background: The objective of the present study was first to examine whether dynamic smoking cues in movies trigger craving, and second to explore whether the DRD4 48 bp variable number of tandem repeat (VNTR) exon 3 genotype modifies this relationship. Using an experimental design, daily adult smoke

  17. Evolution of alternative splicing regulation: changes in predicted exonic splicing regulators are not associated with changes in alternative splicing levels in primates

    DEFF Research Database (Denmark)

    Irimia, Manuel; Rukov, Jakob Lewin; Roy, Scott William

    2009-01-01

    Alternative splicing is tightly regulated in a spatio-temporal and quantitative manner. This regulation is achieved by a complex interplay between spliceosomal (trans) factors that bind to different sequence (cis) elements. cis-elements reside in both introns and exons and may either enhance...... of interspecific differences in these elements on the evolution of alternative splicing levels has not yet been investigated at genomic level. Here we study the effect of interspecific differences in predicted exonic splicing regulators (ESRs) on exon inclusion levels in human and chimpanzee. For this purpose, we...... and changes in alternative splicing levels. This observation holds across different ESR exon positions, exon lengths, and 5' splice site strengths. We suggest that this lack of association is mainly due to the great importance of context for ESR functionality: many ESR-like motifs in primates may have little...

  18. Haplotype determination of the upstream regulatory region and the second exon of the BoLA-DRB3 gene in Holstein cattle.

    Science.gov (United States)

    Goszczynski, D E; Ripoli, M V; Takeshima, S-N; Baltian, L; Aida, Y; Giovambattista, G

    2014-03-01

    Polymorphisms of the BoLA-DRB3 gene are located primarily in the second exon [antigen binding site (ABS)] and, to a lesser extent, in the upstream regulatory region (URR). It can be hypothesised that exon 2 and the URR are under different types of natural selection. The aim of this work was to determine the URR-exon 2 haplotypes; 34 Holstein samples were genotyped by direct sequencing. A total of 7 URR alleles and 23 exon 2 alleles were detected, and 3 of the URR alleles were novel. Our results may suggest that no relationship exists between the URR and exon 2 of the BoLA-DRB3 gene (linkage disequilibrium P value > 0.05), most likely due to recombination over time. Our results also suggest that both regions of class II genes may be included in the development of new genotyping methods based on next-generation DNA sequencing technologies.

  19. A nonsense mutation in the 4-hydroxyphenylpyruvic acid dioxygenase gene (Hpd) causes skipping of the constitutive exon and hypertyrosinemia in mouse strain III

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Fumio; Awata, Hisataka; Matsuda, Ichiro [Kumamoto Univ. (Japan)

    1995-01-01

    4-Hydroxyphenylpyruvic acid dioxygenase (HPD; EC 1.13.11.27) is an important enzyme in tyrosine catabolism in most organisms. Decreased activity of 4-hydroxyphenylpyruvic acid dioxygenase in the liver of mouse strain III is associated with tyrosinemia. We report a nucleotide substitution that generates a termination codon in exon 7 of the 4-hydroxyphenylpyruvic acid dioxygenase gene in III mice. This mutation is associated with partial exon skipping, and most of the mRNA lacks sequences corresponding to exon 7. The partial exon skipping apparently is the result of a nonsense mutation in the exon. Mouse strain III is a model for human tyrosinemia type 3 (McKusick 276710), and this train together with recently established models for tyrosinemia type 1 will facilitate studies of hereditary tyrosinemias.

  20. A nonsense mutation in the 4-hydroxyphenylpyruvic acid dioxygenase gene (Hpd) causes skipping of the constitutive exon and hypertyrosinemia in mouse strain III.

    Science.gov (United States)

    Endo, F; Awata, H; Katoh, H; Matsuda, I

    1995-01-01

    4-Hydroxyphenylpyruvic acid dioxygenase (HPD; EC 1.13.11.27) is an important enzyme in tyrosine catabolism in most organisms. Decreased activity of 4-hydroxyphenylpyruvic acid dioxygenase in the liver of mouse strain III is associated with tyrosinemia. We report a nucleotide substitution that generates a termination codon in exon 7 of the 4-hydroxyphenylpyruvic acid dioxygenase gene in III mice. This mutation is associated with partial exon skipping, and most of the mRNA lacks sequences corresponding to exon 7. The partial exon skipping apparently is the result of a nonsense mutation in the exon. Mouse strain III is a model for human tyrosinemia type 3 (McKusick 276710), and this strain together with recently established models for tyrosinemia type 1 will facilitate studies of hereditary tyrosinemias.

  1. Altered splicing of the BIN1 muscle-specific exon in humans and dogs with highly progressive centronuclear myopathy.

    Directory of Open Access Journals (Sweden)

    Johann Böhm

    2013-06-01

    Full Text Available Amphiphysin 2, encoded by BIN1, is a key factor for membrane sensing and remodelling in different cell types. Homozygous BIN1 mutations in ubiquitously expressed exons are associated with autosomal recessive centronuclear myopathy (CNM, a mildly progressive muscle disorder typically showing abnormal nuclear centralization on biopsies. In addition, misregulation of BIN1 splicing partially accounts for the muscle defects in myotonic dystrophy (DM. However, the muscle-specific function of amphiphysin 2 and its pathogenicity in both muscle disorders are not well understood. In this study we identified and characterized the first mutation affecting the splicing of the muscle-specific BIN1 exon 11 in a consanguineous family with rapidly progressive and ultimately fatal centronuclear myopathy. In parallel, we discovered a mutation in the same BIN1 exon 11 acceptor splice site as the genetic cause of the canine Inherited Myopathy of Great Danes (IMGD. Analysis of RNA from patient muscle demonstrated complete skipping of exon 11 and BIN1 constructs without exon 11 were unable to promote membrane tubulation in differentiated myotubes. Comparative immunofluorescence and ultrastructural analyses of patient and canine biopsies revealed common structural defects, emphasizing the importance of amphiphysin 2 in membrane remodelling and maintenance of the skeletal muscle triad. Our data demonstrate that the alteration of the muscle-specific function of amphiphysin 2 is a common pathomechanism for centronuclear myopathy, myotonic dystrophy, and IMGD. The IMGD dog is the first faithful model for human BIN1-related CNM and represents a mammalian model available for preclinical trials of potential therapies.

  2. Intronic L1 retrotransposons and nested genes cause transcriptional interference by inducing intron retention, exonization and cryptic polyadenylation.

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    Kristel Kaer

    Full Text Available BACKGROUND: Transcriptional interference has been recently recognized as an unexpectedly complex and mostly negative regulation of genes. Despite a relatively few studies that emerged in recent years, it has been demonstrated that a readthrough transcription derived from one gene can influence the transcription of another overlapping or nested gene. However, the molecular effects resulting from this interaction are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using in silico chromosome walking, we searched for prematurely terminated transcripts bearing signatures of intron retention or exonization of intronic sequence at their 3' ends upstream to human L1 retrotransposons, protein-coding and noncoding nested genes. We demonstrate that transcriptional interference induced by intronic L1s (or other repeated DNAs and nested genes could be characterized by intron retention, forced exonization and cryptic polyadenylation. These molecular effects were revealed from the analysis of endogenous transcripts derived from different cell lines and tissues and confirmed by the expression of three minigenes in cell culture. While intron retention and exonization were comparably observed in introns upstream to L1s, forced exonization was preferentially detected in nested genes. Transcriptional interference induced by L1 or nested genes was dependent on the presence or absence of cryptic splice sites, affected the inclusion or exclusion of the upstream exon and the use of cryptic polyadenylation signals. CONCLUSIONS/SIGNIFICANCE: Our results suggest that transcriptional interference induced by intronic L1s and nested genes could influence the transcription of the large number of genes in normal as well as in tumor tissues. Therefore, this type of interference could have a major impact on the regulation of the host gene expression.

  3. The pivotal roles of TIA proteins in 5' splice-site selection of alu exons and across evolution.

    Directory of Open Access Journals (Sweden)

    Nurit Gal-Mark

    2009-11-01

    Full Text Available More than 5% of alternatively spliced internal exons in the human genome are derived from Alu elements in a process termed exonization. Alus are comprised of two homologous arms separated by an internal polypyrimidine tract (PPT. In most exonizations, splice sites are selected from within the same arm. We hypothesized that the internal PPT may prevent selection of a splice site further downstream. Here, we demonstrate that this PPT enhanced the selection of an upstream 5' splice site (5'ss, even in the presence of a stronger 5'ss downstream. Deletion of this PPT shifted selection to the stronger downstream 5'ss. This enhancing effect depended on the strength of the downstream 5'ss, on the efficiency of base-pairing to U1 snRNA, and on the length of the PPT. This effect of the PPT was mediated by the binding of TIA proteins and was dependent on the distance between the PPT and the upstream 5'ss. A wide-scale evolutionary analysis of introns across 22 eukaryotes revealed an enrichment in PPTs within approximately 20 nt downstream of the 5'ss. For most metazoans, the strength of the 5'ss inversely correlated with the presence of a downstream PPT, indicative of the functional role of the PPT. Finally, we found that the proteins that mediate this effect, TIA and U1C, and in particular their functional domains, are highly conserved across evolution. Overall, these findings expand our understanding of the role of TIA1/TIAR proteins in enhancing recognition of exons, in general, and Alu exons, in particular.

  4. The pivotal roles of TIA proteins in 5' splice-site selection of alu exons and across evolution.

    Directory of Open Access Journals (Sweden)

    Nurit Gal-Mark

    2009-11-01

    Full Text Available More than 5% of alternatively spliced internal exons in the human genome are derived from Alu elements in a process termed exonization. Alus are comprised of two homologous arms separated by an internal polypyrimidine tract (PPT. In most exonizations, splice sites are selected from within the same arm. We hypothesized that the internal PPT may prevent selection of a splice site further downstream. Here, we demonstrate that this PPT enhanced the selection of an upstream 5' splice site (5'ss, even in the presence of a stronger 5'ss downstream. Deletion of this PPT shifted selection to the stronger downstream 5'ss. This enhancing effect depended on the strength of the downstream 5'ss, on the efficiency of base-pairing to U1 snRNA, and on the length of the PPT. This effect of the PPT was mediated by the binding of TIA proteins and was dependent on the distance between the PPT and the upstream 5'ss. A wide-scale evolutionary analysis of introns across 22 eukaryotes revealed an enrichment in PPTs within approximately 20 nt downstream of the 5'ss. For most metazoans, the strength of the 5'ss inversely correlated with the presence of a downstream PPT, indicative of the functional role of the PPT. Finally, we found that the proteins that mediate this effect, TIA and U1C, and in particular their functional domains, are highly conserved across evolution. Overall, these findings expand our understanding of the role of TIA1/TIAR proteins in enhancing recognition of exons, in general, and Alu exons, in particular.

  5. A DNMT3B alternatively spliced exon and encoded peptide are novel biomarkers of human pluripotent stem cells.

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    Sailesh Gopalakrishna-Pillai

    Full Text Available A major obstacle in human stem cell research is the limited number of reagents capable of distinguishing pluripotent stem cells from partially differentiated or incompletely reprogrammed derivatives. Although human embryonic stem cells (hESCs and induced pluripotent stem cells (iPSCs express numerous alternatively spliced transcripts, little attention has been directed at developing splice variant-encoded protein isoforms as reagents for stem cell research. In this study, several genes encoding proteins involved in important signaling pathways were screened to detect alternatively spliced transcripts that exhibited differential expression in pluripotent stem cells (PSCs relative to spontaneously differentiated cells (SDCs. Transcripts containing the alternatively spliced exon 10 of the de novo DNA methyltransferase gene, DNMT3B, were identified that are expressed in PSCs. To demonstrate the utility and superiority of splice variant specific reagents for stem cell research, a peptide encoded by DNMT3B exon 10 was used to generate an antibody, SG1. The SG1 antibody detects a single DNMT3B protein isoform that is expressed only in PSCs but not in SDCs. The SG1 antibody is also demonstrably superior to other antibodies at distinguishing PSCs from SDCs in mixed cultures containing both pluripotent stem cells and partially differentiated derivatives. The tightly controlled down regulation of DNMT3B exon 10 containing transcripts (and exon 10 encoded peptide upon spontaneous differentiation of PSCs suggests that this DNMT3B splice isoform is characteristic of the pluripotent state. Alternatively spliced exons, and the proteins they encode, represent a vast untapped reservoir of novel biomarkers that can be used to develop superior reagents for stem cell research and to gain further insight into mechanisms controlling stem cell pluripotency.

  6. Deletion of exon 8 from the EXT1 gene causes multiple osteochondromas (MO) in a family with three affected members.

    Science.gov (United States)

    Zhuang, Lei; Gerber, Simon D; Kuchen, Stefan; Villiger, Peter M; Trueb, Beat

    2016-01-01

    Multiple osteochondromas (also called hereditary multiple exostoses) is an autosomal dominant disorder characterized by multiple cartilaginous tumors, which are caused by mutations in the genes for exostosin-1 (EXT1) and exostosin-2 (EXT2). The goal of this study was to elucidate the genetic alterations in a family with three affected members. Isolation of RNA from the patients' blood followed by reverse transcription and PCR amplification of selected fragments showed that the three patients lack a specific region of 90 bp from their EXT1 mRNA. This region corresponds to the sequence of exon 8 from the EXT1 gene. No splice site mutation was found around exon 8. However, long-range PCR amplification of the region from intron 7 to intron 8 indicated that the three patients contain a deletion of 4318 bp, which includes exon 8 and part of the flanking introns. There is evidence that the deletion was caused by non-homologous end joining because the breakpoints are not located within a repetitive element, but contain multiple copies of the deletion hotspot sequence TGRRKM. Exon 8 encodes part of the active site of the EXT1 enzyme, including the DXD signature of all UDP-sugar glycosyltransferases. It is conceivable that the mutant protein exerts a dominant negative effect on the activity of the EXT glycosyltransferase since it might interact with normal copies of the enzyme to form an inactive hetero-oligomeric complex. We suggest that sequencing of RNA might be superior to exome sequencing to detect short deletions of a single exon.

  7. The SNPs Analysis of the Exons of Three Genes of MyoD Gene Family in Seven Swine Breeds (Line)

    Institute of Scientific and Technical Information of China (English)

    LI Jing-fen; LIU Di; YU Hao

    2005-01-01

    The study objects includes seven swine breeds: Minzhu, Sanjiangbaizhu, Yorkshire, Landrace, Junmuyihao, Duroc and Double muscle Yorkshire. According to the sequences of MyoG, MyoD and Myf5 of swine in GenBank, seventeen pairs of primers for MyoG, MyoD and Myf5 were designed. PCR-SSCP technology was applied to detect SNPs of the exons of the three genes. The results showed that no polymorphism was in MyoG and MyoD, and some SNPs were in three exons of Myf5. There was one mutant site in the first exon of Myf5 (G → C), three mutant sites in the second exon of Myf5 (C → A, A → G and G → A); in the third exon of Myf5, there was one base A deficiency at 3 387 bp, three bases T deficiency at 3 417 bp, one mutant site at 3 443 bp (T → C).This study obtained a tendency conclusion that gene frequency of allele M of Myf5 on the one hand is positively correlated with lean meat percentage, on the other hand is correlated with the orientation of selective breeding; it also deduced that allele F is possibly correlated with high lean meat percentage. Through statistical analysis, allele A, B, C of Myf5 have no obvious correlation with lean meat percentage of different swine breeds, In addition, the high polymorphism of Myf5 showed that seven swine breeds are rich in genetic variation, and have high selective competency.

  8. Evolution of the histones: free play with exon shuffling Evolucion de las histonas: Juego libre con reordenamiento de exones al azar

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    G. CECILIA TORO

    2001-03-01

    Full Text Available In higher eukaryotes, the nuclear DNA is organized for transcription, replication and mitosis in competent chromatin and chromosomes. The basic unit of chromatin is the nucleosome. This entity is formed by 168 base pairs of DNA wound around an octamer of histones, this octamer of histones consist of two copies of H2A, H2B, H3 and H4. The DNA is sealed in its input and output point by a histone linker: histone H1. Histones were supposed to be very conserved proteins. However, during the past few years it was found that these proteins present a high degree of divergency in several lower eukaryotes. In Trypanosoma, it was found that histones H3 and H4, which are at the center of the nucleosomal organization, showed more than 30 % of divergency, while histone H1 corresponded to only one of the three peptide domains present in higher eukaryotes. These features of Trypanosoma histones may explain, at least in part, the unability of chromatin to condense into chromosomes during the cell division in these parasites. Evolution of histones was usually considered as peculiar, with several proposals which are difficult to reconcile with experimental data. In the present work, it is proposed that histones followed the same evolutionary route as many other proteins. Considering that exons code for structural and functional domains in proteins and that, at the origin of eukaryotes, the histones, as other proteins, could be formed by "units" (mecano theory, it was expected that these units or domains eventually would be found in living organisms exhibiting primitive features. Furthermore, those units could work independently. Our results on the structure of Trypanosoma cruzi histone genes and proteins as well as the analysis of other histones from different species fit with this proposalEn los eucariontes superiores, el DNA nuclear se organiza en cromatina competente y en cromosomas para la transcripción, replicación y mitosis. La unidad básica de la

  9. Mutations in exon 6 and 7 of the phenylalanine hydroxylase(PAH) gene in chinese patients with phenylketonuria%苯丙酮尿症患儿苯丙氨酸羟化酶exon6基因、exon7基因突变的研究

    Institute of Scientific and Technical Information of China (English)

    周永安; 郁梁; 李素云; 张改秀; 张全斌; 刘建平; 杨建萍; 王钰; 马云霞; 张晓刚

    2011-01-01

    目的 探讨山西省苯丙酮尿症(PKU)患儿的苯丙氨酸羟化酶(PAH)exon6 基因、exon7 基因的突变特征.方法 通过测序及序列比对的方法对56 例PKU 患儿和112 例健康儿童的336 个PAH exon6 基因、exon7 基因进行序列分析,以确定其突变位点、性质和频率.结果 通过序列分析,发现在PKU 患儿和健康儿童中均高频率的出现Q232Q(CAA→CAG)、V245V(GTG→GTA)两种同义突变,其中cDNA 696 位点的频率高达96.2%,cDNA 735 位点的频率高达76.1%.健康儿童的其他序列与Genbank 完全相同.而PKU 患儿的基因序列中还发现了9 种共计37 个突变基因,占全部PAH 突变基因的33.04%.exon 6 仅发现一种突变基因Y204C,突变频率达9.8%;exon 7 中R243Q 的突变率最高,占10.7%,其次为Ivs7 +2 T >A,占5.4%,其余的G247V、R252Q、L255S、R261Q、T278I 和E280K 分别占0.9%、0.9%、0.9%、0.9%、2.7%和0.9%.9 种突变都在之前文献中有过报道,其中有7 种错义突变和2 种剪接位点突变.结论 明确了PAH exon6 基因、exon7 基因的突变种类和分布等特征,表明exon6 基因、exon7 基因中Y204C 和R243Q属于山西人群中PAH 基因突变的热点.%Objective To study mutation in exon 6 and 7 of the gene for the phenylalanine hydroxylase ( PAH) . Methods The mutations in exon 6 and 7 and flanking sequence of PAH gene were detected by DNA sequencing , involved in 56 patients with phenylketonura and112 healthy kids. Results Two synonymous mutations-Q232Q ( CAA→CAG) and V245V ( GTG→GTA) were also detected ,which the frequency of cDNA 696 mutation G type and cDNA735-A point mutation was respectively up tO 96. 2% and 76. 1%,we concluded that the 696 735 wild-type site may be G,A in Shanxi Ptovince. Besides , thirty-seven different mutations account for 33. 04% of mutant alleles,Y204C was found in exon6 ; In exon 7,R243Q was the highest incidence ,accounting for 10. 7%,followed by Ivs7 + 2 T> A,5. 4% ,G247V , R252Q , L255S

  10. Association of LRRK2 exonic variants with susceptibility to Parkinson's disease: a case-control study.

    Science.gov (United States)

    Ross, Owen A; Soto-Ortolaza, Alexandra I; Heckman, Michael G; Aasly, Jan O; Abahuni, Nadine; Annesi, Grazia; Bacon, Justin A; Bardien, Soraya; Bozi, Maria; Brice, Alexis; Brighina, Laura; Van Broeckhoven, Christine; Carr, Jonathan; Chartier-Harlin, Marie-Christine; Dardiotis, Efthimios; Dickson, Dennis W; Diehl, Nancy N; Elbaz, Alexis; Ferrarese, Carlo; Ferraris, Alessandro; Fiske, Brian; Gibson, J Mark; Gibson, Rachel; Hadjigeorgiou, Georgios M; Hattori, Nobutaka; Ioannidis, John P A; Jasinska-Myga, Barbara; Jeon, Beom S; Kim, Yun Joong; Klein, Christine; Kruger, Rejko; Kyratzi, Elli; Lesage, Suzanne; Lin, Chin-Hsien; Lynch, Timothy; Maraganore, Demetrius M; Mellick, George D; Mutez, Eugénie; Nilsson, Christer; Opala, Grzegorz; Park, Sung Sup; Puschmann, Andreas; Quattrone, Aldo; Sharma, Manu; Silburn, Peter A; Sohn, Young Ho; Stefanis, Leonidas; Tadic, Vera; Theuns, Jessie; Tomiyama, Hiroyuki; Uitti, Ryan J; Valente, Enza Maria; van de Loo, Simone; Vassilatis, Demetrios K; Vilariño-Güell, Carles; White, Linda R; Wirdefeldt, Karin; Wszolek, Zbigniew K; Wu, Ruey-Meei; Farrer, Matthew J

    2011-10-01

    Background The leucine-rich repeat kinase 2 gene (LRRK2) harbours highly penetrant mutations that are linked to familial parkinsonism. However, the extent of its polymorphic variability in relation to risk of Parkinson's disease (PD) has not been assessed systematically. We therefore assessed the frequency of LRRK2 exonic variants in individuals with and without PD, to investigate the role of the variants in PD susceptibility. LRRK2 was genotyped in patients with PD and controls from three series (white, Asian, and Arab-Berber) from sites participating in the Genetic Epidemiology of Parkinson's Disease Consortium. Genotyping was done for exonic variants of LRRK2 that were identified through searches of literature and the personal communications of consortium members. Associations with PD were assessed by use of logistic regression models. For variants that had a minor allele frequency of 0·5% or greater, single variant associations were assessed, whereas for rarer variants information was collapsed across variants. 121 exonic LRRK2 variants were assessed in 15 540 individuals: 6995 white patients with PD and 5595 controls, 1376 Asian patients and 962 controls, and 240 Arab-Berber patients and 372 controls. After exclusion of carriers of known pathogenic mutations, new independent risk associations were identified for polymorphic variants in white individuals (M1646T, odds ratio 1·43, 95% CI 1·15-1·78; p=0·0012) and Asian individuals (A419V, 2·27, 1·35-3·83; p=0·0011). A protective haplotype (N551K-R1398H-K1423K) was noted at a frequency greater than 5% in the white and Asian series, with a similar finding in the Arab-Berber series (combined odds ratio 0·82, 0·72-0·94; p=0·0043). Of the two previously reported Asian risk variants, G2385R was associated with disease (1·73, 1·20-2·49; p=0·0026), but no association was noted for R1628P (0·62, 0·36-1·07; p=0·087). In the Arab-Berber series, Y2189C showed potential evidence of risk association with

  11. Structure of the human zinc finger protein HIVEP3: molecular cloning, expression, exon-intron structure, and comparison with paralogous genes HIVEP1 and HIVEP2.

    Science.gov (United States)

    Hicar, M D; Liu, Y; Allen, C E; Wu, L C

    2001-01-01

    Here we report the cloning and characterization of HIVEP3, the newest member in the human immunodeficiency virus type 1 enhancer-binding protein family that encodes large zinc finger proteins and regulates transcription via the kappaB enhancer motif. The largest open reading frame of HIVEP3 contains 2406 aa. and is approximately 80% identical to the mouse counterpart. The HIVEP3 gene is located in the chromosomal region 1p34 and is at least 300 kb with 10 exons. RNA studies show that multiple HIVEP3 transcripts are differentially expressed and regulated. Additionally, transcription termination occurs in the ultimate exon, exon 10, or in exon 6. Therefore, HIVEP3 may produce protein isoforms that contain or exclude the carboxyl DNA binding domain and the leucine zipper by alternative RNA splicing and differential polyadenylation. Sequence homologous to HIVEP3 exon 6 is not found in mouse nor are the paralogous genes HIVEP1 and HIVEP2. Zoo-blot analysis suggests that sequences homologous to the human exon 6 are present only in primates and cow. Therefore, a foreign DNA harboring a termination exon likely was inserted into the HIVEP3 locus relatively recently in evolution, resulting in the acquisition of novel gene regulatory mechanisms as well as the generation of structural and functional diversity. Copyright 2001 Academic Press.

  12. Muscleblind-like 1 activates insulin receptor exon 11 inclusion by enhancing U2AF65 binding and splicing of the upstream intron.

    Science.gov (United States)

    Echeverria, Gloria V; Cooper, Thomas A

    2014-02-01

    Alternative splicing regulates developmentally and tissue-specific gene expression programs, disruption of which have been implicated in numerous diseases. Muscleblind-like 1 (MBNL1) regulates splicing transitions, which are disrupted on loss of MBNL1 function in myotonic dystrophy type 1 (DM1). One such event is MBNL1-mediated activation of insulin receptor exon 11 inclusion, which requires an intronic enhancer element downstream of exon 11. The mechanism of MBNL1-mediated activation of exon inclusion is unknown. We developed an in vitro splicing assay, which robustly recapitulates MBNL1-mediated splicing activation of insulin receptor exon 11 and found that MBNL1 activates removal of the intron upstream of exon 11 upon binding its functional response element in the downstream intron. MBNL1 enhances early spliceosome assembly as evidenced by enhanced complex A formation and binding of U2 small nuclear ribonucleoprotein auxiliary factor 65 kDa subunit (U2AF65) on the upstream intron. We demonstrated that neither the 5' splice site nor exon 11 sequences are required for MBNL1-activated U2AF65 binding. Interestingly, the 5' splice site is required for MBNL1-mediated activation of upstream intron removal, although MBNL1 has no effect on U1 snRNA recruitment. These results suggest that MBNL1 directly activates binding of U2AF65 to enhance upstream intron removal to ultimately activate alternative exon inclusion.

  13. Mechanistic Evaluation for Mixed-field Agglutination in the K562 Cell Study Model with Exon 3 Deletion of A1 Gene.

    Science.gov (United States)

    Chen, Ding-Ping; Tseng, Ching-Ping; Lin, Chi-Jui; Wang, Wei-Ting; Sun, Chien-Feng

    2015-01-01

    In the case of blood type B3 with typical mixed-field agglutination of RBCs in the presence of anti-B or anti-AB antibody, a number of genetic alternations have been reported. It is well known that the IVS3+5G→A mutation in the B gene destroys the consensus of the splice donor site leading to exon 3 skipping during mRNA splicing. The lack of exon 3 likely causes a short stem region, producing an unstable B3 protein, and is concomitant with a decrease in B3 protein expression. Whether the phenomenon also appears in the type A blood group is of question. In this study, we evaluate whether exon 3 deletion in the blood type A gene also results in mixed-field phenotype. Site-directed mutagenesis was used to generate cDNA encoding A1 gene with exon 3 deletion. The cDNA was stably expressed in K562 cells. The expression of A antigen was compared with expression in parental K562 cells that did not express A antigen and in the stable K562 cell line expressing A(1) cDNA by flow cytometry analyses. The expression of A antigen in A1 stable cells and parental K562 cells was set as 100% and 0%, respectively. The mean relative percentage of A antigen expression for the cells of A1 with exon 3 deletion was 59.9% of A1 stable cells. Consistent with the observations of B3, which is B gene with exon 3 deletion, mixed field agglutination was observed for the cells expressing A1 with exon 3 deletion. Exon 3 deletion results in mixed field phenotype in both type A and B RBCs. However, the degree of antigen expression change for exon 3 deletion in A gene was less severe when compared with the deletion occurred in B gene.

  14. A case of Becker muscular dystrophy resulting from the skipping of four contiguous exons (71-74) of the dystrophin gene during mRNA maturation.

    Science.gov (United States)

    Patria, S Y; Alimsardjono, H; Nishio, H; Takeshima, Y; Nakamura, H; Matsuo, M

    1996-07-01

    The mutations in one-third of both Duchenne and Becker muscular dystrophy patients remain unknown because they do not involve gross rearrangements of the dystrophin gene. Here we report the first example of multiple exon skipping during the splicing of dystrophin mRNA precursor encoded by an apparently normal dystrophin gene. A 9-year-old Japanese boy exhibiting excessive fatigue and high serum creatine kinase activity was examined for dystrophinopathy. An immunohistochemical study of muscle tissue biopsy disclosed faint and discontinuous staining of the N-terminal and rod domains of dystrophin but no staining at all of the C-terminal domain of dystrophin. The dystrophin transcript from muscle tissue was analyzed by the reverse transcriptase polymerase chain reaction. An amplified product encompassing exons 67-79 of dystrophin cDNA was found to be smaller than that of the wild-type product. Sequence analysis of this fragment showed that the 3' end of exon 70 was directly connected to the 5' end of exon 75 and, thus, that exons 71-74 were completely absent. As a result, a truncated dystrophin protein lacking 110 amino acids from the C-terminal domain should result from translation of this truncated mRNA, and the patient was diagnosed as having Becker muscular dystrophy at the molecular level. Genomic DNA was analyzed to identify the cause of the disappearance of these exons. Every exon-encompassing region could be amplified from genomic DNA, indicating that the dystrophin gene is intact. Furthermore, sequencing of these amplified products did not disclose any particular nucleotide change that could be responsible for the multiple exon skipping observed. Considering that exons 71-74 are spliced out alternatively in some tissue-specific isoforms, to suppose that the alternative splicing machinery is present in the muscle tissue of the index case and that it is activated by an undetermined mechanism is reasonable. These results illustrate a novel genetic anomaly that

  15. The point mutation of p53 gene exon7 in hepatocellular carcinoma from Anhui Province, a non HCC prevalent area in China

    Institute of Scientific and Technical Information of China (English)

    Hu Liu; Yuan Wang; Qing Zhou; Shu-Yu Gui; Xu Li

    2002-01-01

    AIM: In hepatocellular carcinoma (HCC) prevalent areas ofChina, the point mutation of p53 exon7 is highly correlatedwith Hepatitis B virus(HBV) infection and aflatoxin B intake.While in non-HCC-prevalent areas of China, these factorsare not so important in the etiology of HCC. Therefore, thepoint mutation of p.53 exon7 may also be different than thatin HCC-prevalent areas of China. The aim of this study is toinvestigate the status and carcinogenic role of the pointmutation of p53 gene exon7 in hepatocellular carcinoma fromAnhui Province, a non-HCC-prevalent area in China.METHODS: PCR,PCR-SSCP and PCR-RFLP were applied toanalyze the homozygous deletion and point mutation of p53exon7 in HCC samples from Anhui, which were confirmedby DNA sequencing and Genbank comparison.RESULTS: In the 38 samples of hepatocellular carcinoma, nohomozygous deletion of p53 exon7 was detected and pointmutations of p53 exon7 were found in 4 cases, which werefound to be heterozygous mutation of codon 249 With amutation rate of 10.53 %(4/38). The third base mutstion(G→T) of p53 codon 249 was found by DNA sequencing andGenbank comparison.CONCLUSION: The incidence of point mutation of p53 codon249 is lower in hepatocellular carcinoma and theheterozygous mutation of p53 exon7 found in these patientsonly indicate that they have genetic susceptibility to HCC.p53 codon 249 is a hotspot of p53 exon7 point mutation,suggesting that the point mutation of p53 exon 7 may notplay a major role in the carcinogenesis of HCC in AnhuiProvince, a non-HCC-prsvalent area in China.

  16. Identification of true EST alignments and exon regions of gene sequences

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yanhong; JING Hui; LI Yanen; LIU Huailan

    2004-01-01

    Expressed sequence tags (ESTs), which have piled up considerably so far, provide a valuable resource for finding new genes, disease-relevant genes, and for recognizing alternative splicing variants, SNP sites, etc. The prerequisite for carrying out these researches is to correctly ascertain the gene-sequence-related ESTs. Based on analysis of the alignment results between some known gene sequences and ESTs in public database, several measures including Identity Check, Gap Check, Inclusion Check and Length Check have been introduced to judge whether an EST alignment is related to a gene sequence or not. A computational program EDSAc1.0 has been developed to identify true EST alignments and exon regions of query gene sequences. When tested with human gene sequences in the standard dataset HMR195 and evaluated with the standard measures of gene prediction performance, EDSAc1.0 can identify protein- coding regions with specificity of 0.997 and sensitivity of 0.88 at the nucleotide level, which outperform that of the counterpart TAP. A web server of EDSAc1.0 is available at http://infosci.hust.edu.cn.

  17. Effect of BRCA2 sequence variants predicted to disrupt exonic splice enhancers on BRCA2 transcripts

    Directory of Open Access Journals (Sweden)

    Brewster Brooke L

    2010-05-01

    Full Text Available Abstract Background Genetic screening of breast cancer patients and their families have identified a number of variants of unknown clinical significance in the breast cancer susceptibility genes, BRCA1 and BRCA2. Evaluation of such unclassified variants may be assisted by web-based bioinformatic prediction tools, although accurate prediction of aberrant splicing by unclassified variants affecting exonic splice enhancers (ESEs remains a challenge. Methods This study used a combination of RT-PCR analysis and splicing reporter minigene assays to assess five unclassified variants in the BRCA2 gene that we had previously predicted to disrupt an ESE using bioinformatic approaches. Results Analysis of BRCA2 c.8308 G > A (p.Ala2770Thr by mRNA analysis, and BRCA2 c.8962A > G (p.Ser2988Gly, BRCA2 c.8972G > A (p.Arg2991His, BRCA2 c.9172A > G (p.Ser3058Gly, and BRCA2 c.9213G > T (p.Glu3071Asp by a minigene assay, revealed no evidence for aberrant splicing. Conclusions These results illustrate the need for improved methods for predicting functional ESEs and the potential consequences of sequence variants contained therein.

  18. POF and HP1 bind expressed exons, suggesting a balancing mechanism for gene regulation.

    Science.gov (United States)

    Johansson, Anna-Mia; Stenberg, Per; Pettersson, Fredrik; Larsson, Jan

    2007-11-01

    Two specific chromosome-targeting and gene regulatory systems are present in Drosophila melanogaster. The male X chromosome is targeted by the male-specific lethal complex believed to mediate the 2-fold up-regulation of the X-linked genes, and the highly heterochromatic fourth chromosome is specifically targeted by the Painting of Fourth (POF) protein, which, together with heterochromatin protein 1 (HP1), modulates the expression level of genes on the fourth chromosome. Here we use chromatin immunoprecipitation and tiling microarray analysis to map POF and HP1 on the fourth chromosome in S2 cells and salivary glands at high resolution. The enrichment profiles were complemented by transcript profiles to examine the link between binding and transcripts. The results show that POF specifically binds to genes, with a strong preference for exons, and the HP1 binding profile is a mirror image of POF, although HP1 displays an additional "peak" in the promoter regions of bound genes. HP1 binding within genes is much higher than the basal HP1 enrichment on Chromosome 4. Our results suggest a balancing mechanism for the regulation of the fourth chromosome where POF and HP1 competitively bind at increasing levels with increased transcriptional activity. In addition, our results contradict transposable elements as a major nucleation site for HP1 on the fourth chromosome.

  19. POF and HP1 bind expressed exons, suggesting a balancing mechanism for gene regulation.

    Directory of Open Access Journals (Sweden)

    Anna-Mia Johansson

    2007-11-01

    Full Text Available Two specific chromosome-targeting and gene regulatory systems are present in Drosophila melanogaster. The male X chromosome is targeted by the male-specific lethal complex believed to mediate the 2-fold up-regulation of the X-linked genes, and the highly heterochromatic fourth chromosome is specifically targeted by the Painting of Fourth (POF protein, which, together with heterochromatin protein 1 (HP1, modulates the expression level of genes on the fourth chromosome. Here we use chromatin immunoprecipitation and tiling microarray analysis to map POF and HP1 on the fourth chromosome in S2 cells and salivary glands at high resolution. The enrichment profiles were complemented by transcript profiles to examine the link between binding and transcripts. The results show that POF specifically binds to genes, with a strong preference for exons, and the HP1 binding profile is a mirror image of POF, although HP1 displays an additional "peak" in the promoter regions of bound genes. HP1 binding within genes is much higher than the basal HP1 enrichment on Chromosome 4. Our results suggest a balancing mechanism for the regulation of the fourth chromosome where POF and HP1 competitively bind at increasing levels with increased transcriptional activity. In addition, our results contradict transposable elements as a major nucleation site for HP1 on the fourth chromosome.

  20. Multiple non-coding exons and alternative splicing in the mouse Mas protooncogene.

    Science.gov (United States)

    Alenina, Natalia; Böhme, Ilka; Bader, Michael; Walther, Thomas

    2015-09-01

    The Mas protooncogene encodes a G protein-coupled receptor with the common seven transmembrane domains, expressed mainly in the testis and brain. We provided evidence that Mas is a functional angiotensin-(1-7) receptor and can interact with the angiotensin II type 1 (AT1) receptor. The gene is transcriptionally regulated during development in the brain and testis, but its structure was unresolved. In this study we used 5'- and 3'-RACE, RT-PCR, and RNase-protection assays to elucidate the complete Mas gene structure and organization. We identified 12 exons in the mouse Mas gene with 11 in the 5' untranslated mRNA, which can be alternatively spliced. We also showed that Mas transcription can start from 4 tissue-specific promoters, whereby testis-specific Mas mRNA is transcribed from two upstream promoters, and the expression of Mas in the brain starts from two downstream promoters. Alternative splicing and multiple promoter usage result in at least 12 Mas transcripts in which different 5' untranslated regions are fused to a common coding sequence. Moreover, termination of Mas mRNA is regulated by two different polyadenylation signals. The gene spans approximately 27 kb, and the longest detected mRNA contains 2,451 bp. Thus, our results characterize the Mas protooncogene as the gene with the most complex gene structure of all described members of the gene family coding for G protein-coupled receptors. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Tandem duplication of KIT exon 11 influences the proteome of canine mast cell tumours.

    Science.gov (United States)

    Schlieben, P; Meyer, A; Weise, C; Bondzio, A; Gruber, A D; Klopfleisch, R

    2013-05-01

    Mutations with permanent activation of the stem cell factor receptor KIT have been identified as one potential cause for canine cutaneous mast cell tumours (MCTs). The exact changes in global gene expression patterns associated with permanent activation of KIT in these tumours are unknown. The present study compares, by the use of two dimensional difference gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, the proteomes of canine MCTs, with and without KIT exon 11 tandem duplication. Fifteen differentially expressed proteins were identified in mutated MCTs. These are mainly involved in cytoskeleton structure and cell motility (ACTR2, ACTB and CAPPA1), cell signalling (ARHGDIA) and lipid metabolism (ALOX15 and ACSBG4), or are serum proteins. The results therefore support the notion that KIT mutation is associated with changes in the proteome of affected cells with a major effect on the composition of the cytoskeletal proteome and cell motility proteins. No overlaps were identified when the results were compared with a recent study on the proteomic differences between low- and high-grade tumours, suggesting that KIT-mutated tumours may be regarded as a separate entity of high-grade tumours with potential relevance to therapeutic strategies.

  2. Sequence polymorphism of PrP exon 3 gene in Istrian and crossbred sheep

    Directory of Open Access Journals (Sweden)

    Ino Curik

    2010-01-01

    Full Text Available Polymorphisms in sheep PrP (prion protein gene are known for scrapie susceptibility. We sequenced part of PrP exon 3 gene in 92 autochthonous Istrian (IS and 38 crossbred sheep (CBS. ARQ, ARR and AHQ alleles were predominant with frequency of 0.674 (0.526, 0.228 (0.132 and 0.082 (0.263 in IS (CBS, respectively, while VRQ (0.011 in IS and ARH (0.005 in IS and 0.079 in CBS alleles were rare. We also found non-synonymous mutations at codons 112 (M→T, 127 (G→S and 143 (H→R, and synonymous mutations at codons 231 (R and 237 (L. Additional mutations were associated only with AHQ, ARH and ARQ alleles. The polymorphism of PrP gene in IS was not critical with respect to scrapie susceptibility and with some efforts number of “favourable” genotypes can be increased.

  3. Deletion of amelotin exons 3–6 is associated with amelogenesis imperfecta

    Science.gov (United States)

    Smith, Claire E.L.; Murillo, Gina; Brookes, Steven J.; Poulter, James A.; Silva, Sandra; Kirkham, Jennifer; Inglehearn, Chris F.; Mighell, Alan J.

    2016-01-01

    Amelogenesis imperfecta (AI) is a heterogeneous group of genetic conditions that result in defective dental enamel formation. Amelotin (AMTN) is a secreted protein thought to act as a promoter of matrix mineralization in the final stage of enamel development, and is strongly expressed, almost exclusively, in maturation stage ameloblasts. Amtn overexpression and Amtn knockout mouse models have defective enamel with no other associated phenotypes, highlighting AMTN as an excellent candidate gene for human AI. However, no AMTN mutations have yet been associated with human AI. Using whole exome sequencing, we identified an 8,678 bp heterozygous genomic deletion encompassing exons 3-6 of AMTN in a Costa Rican family segregating dominant hypomineralised AI. The deletion corresponds to an in-frame deletion of 92 amino acids, shortening the protein from 209 to 117 residues. Exfoliated primary teeth from an affected family member had enamel that was of a lower mineral density compared to control enamel and exhibited structural defects at least some of which appeared to be associated with organic material as evidenced using elemental analysis. This study demonstrates for the first time that AMTN mutations cause non-syndromic human AI and explores the human phenotype, comparing it with that of mice with disrupted Amtn function. PMID:27412008

  4. Exon sequencing of PAX3 and T (brachyury) in cases with spina bifida.

    Science.gov (United States)

    Agopian, A J; Bhalla, Angela D; Boerwinkle, Eric; Finnell, Richard H; Grove, Megan L; Hixson, James E; Shimmin, Lawrence C; Sewda, Anshuman; Stuart, Colin; Zhong, Yu; Zhu, Huiping; Mitchell, Laura E

    2013-09-01

    Based on studies in animals and humans, PAX3 and T (brachyury) are candidate genes for spina bifida. However, neither gene has been definitively identified as a risk factor for this condition. Sanger sequencing was used to identify variants in all PAX3 and T exons and promoter regions in 114 spina bifida cases. For known variants, allele frequencies in cases were compared with those from public databases using unadjusted odds ratios. Novel variants were genotyped in parents and assessed for predicted functional impact. We identified common variants in PAX3 (n = 2) and T (n = 3) for which the allele frequencies in cases were significantly different from those reported in at least one public database. We also identified novel variants in both PAX3 (n = 11) and T (n = 1) in spina bifida cases. Several of the novel PAX3 variants are predicted to be highly conserved and/or impact gene function or expression. These studies provide some evidence that common variants of PAX3 and T are associated with spina bifida. Rare and novel variants in these genes were also identified in affected individuals. However, additional studies will be required to determine whether these variants influence the risk of spina bifida. Copyright © 2013 Wiley Periodicals, Inc.

  5. The relationship between gene isoform multiplicity, number of exons and protein divergence.

    Directory of Open Access Journals (Sweden)

    Jordi Morata

    Full Text Available At present we know that phenotypic differences between organisms arise from a variety of sources, like protein sequence divergence, regulatory sequence divergence, alternative splicing, etc. However, we do not have yet a complete view of how these sources are related. Here we address this problem, studying the relationship between protein divergence and the ability of genes to express multiple isoforms. We used three genome-wide datasets of human-mouse orthologs to study the relationship between isoform multiplicity co-occurrence between orthologs (the fact that two orthologs have more than one isoform and protein divergence. In all cases our results showed that there was a monotonic dependence between these two properties. We could explain this relationship in terms of a more fundamental one, between exon number of the largest isoform and protein divergence. We found that this last relationship was present, although with variations, in other species (chimpanzee, cow, rat, chicken, zebrafish and fruit fly. In summary, we have identified a relationship between protein divergence and isoform multiplicity co-occurrence and explained its origin in terms of a simple gene-level property. Finally, we discuss the biological implications of these findings for our understanding of inter-species phenotypic differences.

  6. Computational analysis and prediction for exons of PAC579 genomic sequence

    Institute of Scientific and Technical Information of China (English)

    HUANG; Yi(

    2001-01-01

    [1]Milanesi. L.. Kolchanov, N., Rogozin, I. et al.. Sequence functional inference, in Guide to Human Genome Computing (ed.Bishop. M. J.). Cambridge: Academic Press, 1994, 249-312.[2]Solovyev. V. V., Salamov, A. A., Lawrence, C. B., Predicting internal exons by oligonucleotide composition and discriminant analysis of spliceable open reading frames, Nucleic Acids Res., 1994.22(24): 5156-5163.[3]Borodovsky, M., McIninch, J., GeneMark: parallel gene recognition for both DNA stands, Comp, Chem,, 1993, 17:123-133.[4]Guigo. R.. Knudsen, S, Drake, N. et al., Prediction of gene structure, J. Mol. Biol., 1992, 226(1): 141-157.[5]Kulp, D., Haussler, D., Reese, M. G. et al., A generalized Hidden Markov Model for the recognition of human genes in DNA. ISMB-96. St. Louise: AAAI/MIT Press, 1996.[6]Snyder. E. E.. Stormo, G. D., Identification of protein coding regions in genomic DNA, J. Mol. Biol., 1995, 248(1): 1-18.[7]Xu. Y., Einstein, J. R., Mural, R. J. et al., An improved system for exon recognition and gene modeling in human DNA sequences, in Proc. Int. Conf. lntell. Syst. Mol. Biol., Menlo Park, CA: AAAI Press, 1994, 2: 376-384.[8]Burset. M., Guigo, R., Evaluation of gene structure prediction programs, Genomics, 1996, 34(3): 353-367.[9]Burge. C.. Karlin, S., Prediction of complete gene structures in human genomic DNA, J. Mol. Biol., 1997, 268(l): 78-94.[10]Zhang. M. Q., Identification of protein coding regions in the human genome by quadratic discriminant analysis, Proc. Natl.Acad. Sci. USA, 1997,94(2): 565-568.[11]Mount. S. M., A catalogue of splice junction sequences, Nucleic Acids Res., 1982, 10(2): 459-472.[12]Qin Wenxin. Gu Jianren, Loss of heterozygosity on chromosome 17p13.3 in human malignant tumors, Chinese Bulletin of Life Sciences (in Chinese), 1999, 11(2): 75-77.[13]Li, D., Cao, Y., He, L. et al., Aberrations of p53 gene in human hepatocellular carcinoma from China, Carcinogenesis,1993. 14(2): 169-173.[14

  7. Three types of polymorphisms in exon 14 in porcine Mx1 gene.

    Science.gov (United States)

    Morozumi, T; Sumantri, C; Nakajima, E; Kobayashi, E; Asano, A; Oishi, T; Mitsuhashi, T; Watanabe, T; Hamasima, N

    2001-08-01

    Much is known about the antiviral activity of Mx proteins in species such as mouse and human. In the mouse, loss of resistability to influenza virus has been shown to be due to specific polymorphisms in the Mx gene. This gene is therefore an interesting candidate gene for disease resistance in farm animals. The porcine Mx1 gene has already been identified and characterized based on its homology with mouse Mx1; however, until now no evidence of polymorphisms in the porcine gene has been reported. In this study, we have found two new polymorphisms in exon 14 of porcine Mx1 by DNA sequencing and confirmed their presence in different breeds, using polymerase chain reaction (PCR)-restriction fragment length polymorphisms (RFLP) with NarI and NaeI restriction enzymes. On the basis of the deduced amino acid sequence, one allele contains a deletion that may result in a frameshift to yield several amino acid substitutions and extension of the carboxyl terminal region of Mx1 protein. The deletion allele, Mx1c, was found to be segregating in Landrace, Berkshire, Duroc, Hampshire, and Yucatan miniature pig. A second point mutation, Mx1b, was detected in Meishan and two Vietnamese native pig breeds. All other breeds tested were fixed for the Mx1a allele that is identical to the sequence reported previously. It will be interesting to determine if the Mx1c deletion is associated with variation in resistance to the myxovirus family in the pig.

  8. DEDB: a database of Drosophila melanogaster exons in splicing graph form

    Directory of Open Access Journals (Sweden)

    Tan Tin

    2004-12-01

    Full Text Available Abstract Background A wealth of quality genomic and mRNA/EST sequences in recent years has provided the data required for large-scale genome-wide analysis of alternative splicing. We have capitalized on this by constructing a database that contains alternative splicing information organized as splicing graphs, where all transcripts arising from a single gene are collected, organized and classified. The splicing graph then serves as the basis for the classification of the various types of alternative splicing events. Description DEDB http://proline.bic.nus.edu.sg/dedb/index.html is a database of Drosophila melanogaster exons obtained from FlyBase arranged in a splicing graph form that permits the creation of simple rules allowing for the classification of alternative splicing events. Pfam domains were also mapped onto the protein sequences allowing users to access the impact of alternative splicing events on domain organization. Conclusions DEDB's catalogue of splicing graphs facilitates genome-wide classification of alternative splicing events for genome analysis. The splicing graph viewer brings together genome, transcript, protein and domain information to facilitate biologists in understanding the implications of alternative splicing.

  9. Aminoacylase I deficiency due to ACY1 mRNA exon skipping.

    Science.gov (United States)

    Ferri, L; Funghini, S; Fioravanti, A; Biondi, E G; la Marca, G; Guerrini, R; Donati, M A; Morrone, A

    2014-10-01

    Aminoacylase 1 (ACY1) deficiency is a rare inborn error of metabolism of which less than 20 observations have been described. Patients exhibit urinary excretion of specific N-acetyl amino acids and manifest a heterogeneous clinical spectrum including intellectual disability, motor delay, seizures, moderate to severe mental retardation, absent speech, growth delay, muscular hypotonia and autistic features. Here, we report the case of ACY1 enzyme deficiency in a 6-year-old girl presenting severe intellectual disability, motor retardation, absence of spontaneous locomotor activity and severe speech delay. Urinary excretion of N-acetylated amino acids was present. Mutational analysis of ACY1 gene identified the new homozygous c.1001_1001+5del6 mutation, which alters the mRNA transcription leading to exon 13 skipping and inclusion of a premature stop codon (p.Lys308Glufs*7). A quantitative fluorescent multiplex-polymerase chain reaction (QFM-PCR) assay has been set up and confirmed homozygosity of the mutation in the patient's DNA. Biochemical analysis showed absence of ACY1 enzyme activity in the patient's fibroblasts. The structure of the mutated protein has been defined by homology modeling (HM). Our data endorse the hypothesis of a link between this inborn error of metabolism and the neurological manifestations observed in patients with ACY1 deficiency. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. ADHD candidate gene (DRD4 exon III affects inhibitory control in a healthy sample

    Directory of Open Access Journals (Sweden)

    Marco-Pallarés Josep

    2009-12-01

    Full Text Available Background Dopamine is believed to be a key neurotransmitter in the development of attention-deficit/hyperactivity disorder (ADHD. Several recent studies point to an association of the dopamine D4 receptor (DRD4 gene and this condition. More specifically, the 7 repeat variant of a variable number of tandem repeats (VNTR polymorphism in exon III of this gene is suggested to bear a higher risk for ADHD. In the present study, we investigated the role of this polymorphism in the modulation of neurophysiological correlates of response inhibition (Go/Nogo task in a healthy, high-functioning sample. Results Homozygous 7 repeat carriers showed a tendency for more accurate behavior in the Go/Nogo task compared to homozygous 4 repeat carriers. Moreover, 7 repeat carriers presented an increased nogo-related theta band response together with a reduced go-related beta decrease. Conclusions These data point to improved cognitive functions and prefrontal control in the 7 repeat carriers, probably due to the D4 receptor's modulatory role in prefrontal areas. The results are discussed with respect to previous behavioral data on this polymorphism and animal studies on the impact of the D4 receptor on cognitive functions.

  11. A genome-wide analysis of putative functional and exonic variation associated with extremely high intelligence.

    Science.gov (United States)

    Spain, S L; Pedroso, I; Kadeva, N; Miller, M B; Iacono, W G; McGue, M; Stergiakouli, E; Smith, G D; Putallaz, M; Lubinski, D; Meaburn, E L; Plomin, R; Simpson, M A

    2016-08-01

    Although individual differences in intelligence (general cognitive ability) are highly heritable, molecular genetic analyses to date have had limited success in identifying specific loci responsible for its heritability. This study is the first to investigate exome variation in individuals of extremely high intelligence. Under the quantitative genetic model, sampling from the high extreme of the distribution should provide increased power to detect associations. We therefore performed a case-control association analysis with 1409 individuals drawn from the top 0.0003 (IQ >170) of the population distribution of intelligence and 3253 unselected population-based controls. Our analysis focused on putative functional exonic variants assayed on the Illumina HumanExome BeadChip. We did not observe any individual protein-altering variants that are reproducibly associated with extremely high intelligence and within the entire distribution of intelligence. Moreover, no significant associations were found for multiple rare alleles within individual genes. However, analyses using genome-wide similarity between unrelated individuals (genome-wide complex trait analysis) indicate that the genotyped functional protein-altering variation yields a heritability estimate of 17.4% (s.e. 1.7%) based on a liability model. In addition, investigation of nominally significant associations revealed fewer rare alleles associated with extremely high intelligence than would be expected under the null hypothesis. This observation is consistent with the hypothesis that rare functional alleles are more frequently detrimental than beneficial to intelligence.

  12. Polymorphism in exon2 of BMP15 gene in Iranian sangsari sheep

    Directory of Open Access Journals (Sweden)

    zana pirkhezranian

    2015-04-01

    Full Text Available Fertility rate is an economically important trait in sheep, which is influenced by genetic and environment. So far, three genes have been identified that affects this trait, one of them would be the BMP family, the most famous one is BMP15. Different mutations in the BMP15 gene, increases reproductive performance and growth rate in sheep. The aim of this study was to investigate the genetic and phylogenetic of BMP15 gene sequence in Iranian Sangsari sheep. For this purpose, the blood samples from 20 animal of Damghan station were collected. After DNA extracting, a segment of 222 bp of exon 2 of BMP15 gene was amplified using polymerase chain reaction. Then, all of the PCR products were sequenced. The results showed existence of four haplotypes and three significant mutations of the gene that which one of them was seen for first. In order to determine the genetic distance of Sansari sheep with other animals especially sheep breeds about 103 sequences were taken from Genebank, Then, phylogenetic trees were drawn. Genetic distances and nucleotide differences were calculated. The results showed that goat, cattle and buffalo have minimum genetic distance and monkey, human and mouse have maximum distance with Sangsari sheep and native Hindi and Kashmiri sheep have not any differences with Iranian Sangsari sheep.

  13. Corelation Between Single Nucleotide Polymorphisms in Mu Opioid Receptor Exon 2 and Stereotypic Behaviour in Sows

    Institute of Scientific and Technical Information of China (English)

    LI Jianhong; BAO Jun; CUI Weiguo

    2008-01-01

    Three breeds of sows were observed to investigate the relationship between Single Nucleotide Polymorphisms (SNPs) in Mu Opioid Receptor (MOR) and stereotypic behaviour, such as, sham-chewing, bar biting and standing still in order to better understand the mechanism of stereotypic development of the animals in restrained conditions. MOR exon 2 partial sequences were amplified to analyze single nucleotide polymorphisms by PCR-SSCE One SNP, a silence mutant was found. A significant difference (P<0.01) was found in the frequency of genotypes in these 3 breeds where only the BB genotype, which was identical to that published in GenBank, was found in the Duroc breed, while no AA genotype was found in Landrace, 3 genotypes AA, BB and AB were found in Yorkshire. The result also indicated that the individuals with AA and AB genotypes tended to be more active in sham-chewing than those with the BB genotype (P<0.05). The overall results of this study suggested that sham-chewing of sows may be subjected to both genetic control and environmental conditions, but activity level was more likely to be affected by their environment. We can putatively draw the conclusion that MOR gene has effect on the sham-chewing behavioral traits of sow.

  14. 内蒙古地区3个马品种ELA-DRA* exon2的PCR-SSCP分析%Analyzed ELA-DRA* exon2 of Three Horse Breeds from Inner Mongolia by PCR-SSCP

    Institute of Scientific and Technical Information of China (English)

    孟青龙; 李金莲; 石有斐; 孙玉江; 芒来

    2006-01-01

    为了检测内蒙古地区3个马品种ELA-DRA*exon2的多态性,通过PCR-SSCP技术内蒙古地区3个马品种(三河马、锡尼河马和巴尔虎马)各50匹的ELA-DRA*exon2进行检测,用12%非变性聚丙烯酰胺凝胶电泳将已变性的PCR扩增产物分离,并用银染法显色.结果表明,150匹马中共出现6种基因型:3种纯合子分别记为AA,BB和CC型,均为3条带;3种杂合子分别记为AB,BC和AC型,均为4条带.其中A等位基因频率最高,B次之,而C只在三河马中出现.因此说三河马ELA-DRA *exon2的多态性比锡尼河马和巴尔虎马丰富.

  15. Sequence Variation at exon2 of MHC DRB3 Locus in Bovinae%牛亚科MHC DRB3基因exon2的序列变异分析

    Institute of Scientific and Technical Information of China (English)

    李齐发; 李艳华; 赵兴波; 李学斌; 潘增祥; 谢庄; 李宁

    2005-01-01

    根据牛(Bos taurus)主要组织相容复合体(MHC)DRB3基因的已知序列设计引物,对中国牦牛(B.grunniens)的DRB3基因exon2进行扩增和克隆测序,并根据DRB3基因exon2序列对牛亚科的遗传多样性和分子系统发育进行了分析.结果在234的片段中发现有115个多态位点,多态位点百分率为49.15%.由标准遗传距离和净遗传距离构建的牛亚科系统发育树,可将牛亚科分为5个属,支持将牦牛作为牛亚科中一个独立的属的观点.多态性较丰富的DRB3基因exon2适于属间系统发育分析.

  16. Alternative splicing of exon 17 and a missense mutation in exon 20 of the insulin receptor gene in two brothers with a novel syndrome of insulin resistance (congenital fiber-type disproportion myopathy).

    Science.gov (United States)

    Vorwerk, P; Christoffersen, C T; Müller, J; Vestergaard, H; Pedersen, O; De Meyts, P

    1999-01-01

    The insulin receptor (IR) in two brothers with a rare syndrome of congenital muscle fiber type disproportion myopathy (CFTDM) associated with diabetes and severe insulin resistance was studied. By direct sequencing of Epstein-Barr virus-transformed lymphocytes both patients were found to be compound heterozygotes for mutations in the IR gene. The maternal allele was alternatively spliced in exon 17 due to a point mutation in the -1 donor splice site of the exon. The abnormal skipping of exon 17 shifts the amino acid reading frame and leads to a truncated IR, missing the entire tyrosine kinase domain. In the correct spliced variant, the point mutation is silent and results in a normally translated IR. The paternal allele carries a missense mutation in the tyrosine kinase domain. All three cDNA variants were present in the lymphocytes of the patients. Purified IR from 293 cells overexpressing either of the two mutated receptors lacked basal or stimulated IR beta-subunit autophosphorylation. A third brother who inherited both normal alleles has an normal muscle phenotype and insulin sensitivity, suggesting a direct linkage of these IR mutations with the CFTDM phenotype.

  17. Tuftsin binds neuropilin-1 through a sequence similar to that encoded by exon 8 of vascular endothelial growth factor.

    Science.gov (United States)

    von Wronski, Mathew A; Raju, Natarajan; Pillai, Radhakrishna; Bogdan, Nancy J; Marinelli, Edmund R; Nanjappan, Palaniappa; Ramalingam, Kondareddiar; Arunachalam, Thangavel; Eaton, Steve; Linder, Karen E; Yan, Feng; Pochon, Sibylle; Tweedle, Michael F; Nunn, Adrian D

    2006-03-03

    Tuftsin, Thr-Lys-Pro-Arg (TKPR), is an immunostimulatory peptide with reported nervous system effects as well. We unexpectedly found that tuftsin and a higher affinity antagonist, TKPPR, bind selectively to neuropilin-1 and block vascular endothelial growth factor (VEGF) binding to that receptor. Dimeric and tetrameric forms of TKPPR had greatly increased affinity for neuropilin-1 based on competition binding experiments. On endothelial cells tetrameric TKPPR inhibited the VEGF(165)-induced autophosphorylation of vascular endothelial growth factor receptor-2 (VEGFR-2) even though it did not directly inhibit VEGF binding to VEGFR-2. Homology between exon 8 of VEGF and TKPPR suggests that the sequence coded for by exon 8 may stabilize VEGF binding to neuropilin-1 to facilitate signaling through VEGFR-2. Given the overlap between processes involving neuropilin-1 and tuftsin, we propose that at least some of the previously reported effects of tuftsin are mediated through neuropilin-1.

  18. A V530I Mutation in c-KIT Exon 10 Is Associated to Imatinib Response in Extraabdominal Aggressive Fibromatosis

    Directory of Open Access Journals (Sweden)

    Jean-Emmanuel Kurtz

    2010-01-01

    Full Text Available Aggressive fibromatosis (AF or desmoid tumor is a rare condition, characterized by deep tissue invasion by a monoclonal fibroblastic neoplasm, developed from musculoaponeurotic structures. Surgery is the treatment of choice, but negative margins can hardly been achieved in large tumors, and can lead to major functional disability. AF medical therapy includes nonsteroids anti-inflammatory drugs, tamoxifen, with inconsistent results. Several reports of imatinib efficacy in AF appear in the literature. Here, we describe for the first time a V530I KIT exon 10 mutant that was associated to a dramatic imatinib response in an extraabdominal aggressive fibromatosis. The previously discovered V530I substitution was characterized in the core binding factor AML, but had never been reported in any other condition, so far. In this paper, we discuss the KIT exon 10 mutations or polymorphisms that have been described in a variety of KIT-related conditions, including acute myelogenous leukemia, mastocytosis, and aggressive fibromatosis.

  19. Familial occurrence of typical and severe lethal congenital contractural arachnodactyly caused by missplicing of exon 34 of fibrillin-2

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Mei; Godfrey, M. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Clericuzio, C.L. [Univ. of New Mexico, Albuquerque, NM (United States)

    1996-11-01

    Genetic linkage studies have linked congenital contractual arachnodactyly (CCA), a usually mild heritable connective-tissue disorder, to FBN2, the fibrillin gene on chromosome 5. Recently, FBN2 mutations in two patients with CCA have been described. Here we report an A{r_arrow}T transversion at the -2 position of the consensus acceptor splice site, resulting in the missplicing of exon 34, a calcium-binding epidermal growth factor-like repeat in fibrillin-2 in a mother and daughter with CCA. Significantly, the mother exhibited a classic CCA phenotype with arachnodactyly, joint contractures, and abnormal pinnae, whereas her daughter exhibited a markedly more severe CCA phenotype, which included cardiovascular and gastrointestinal anomalies that led to death in infancy. Analysis of cloned fibroblasts showed that the mother is a somatic mosaic for the exon 34 missplicing mutation, whereas all the daughter`s cells harbored the mutation. 48 refs., 6 figs., 2 tabs.

  20. A highly sensitive quantitative real-time pcr assay for determination of mutant jak2 exon 12 allele burden

    DEFF Research Database (Denmark)

    Kjær, L.; Riley, C.H.; Westman, M.

    2012-01-01

    present a highly sensitive real-time quantitative PCR assay for determination of the mutant allele burden of JAK2 exon 12 mutations. In combination with high resolution melting analysis and sequencing the assay identified six patients carrying previously described JAK2 exon 12 mutations and one novel...... mutation. Two patients were homozygous with a high mutant allele burden, whereas one of the heterozygous patients had a very low mutant allele burden. The allele burden in the peripheral blood resembled that of the bone marrow, except for the patient with low allele burden. Myeloid and lymphoid cell...... populations were isolated by cell sorting and quantitative PCR revealed similar mutant allele burdens in CD16+ granulocytes and peripheral blood. The mutations were also detected in B-lymphocytes in half of the patients at a low allele burden. In conclusion, our highly sensitive assay provides an important...

  1. Identification of two point mutations and a one base deletion in exon 19 of the dystrophin gene by heteroduplex formation.

    Science.gov (United States)

    Prior, T W; Papp, A C; Snyder, P J; Burghes, A H; Sedra, M S; Western, L M; Bartello, C; Mendell, J R

    1993-03-01

    Two thirds of the Duchenne muscular dystrophy population have either gene deletions or duplications. The nondeletion/duplication cases are most likely the result of point mutations or small deletions and duplications that cannot be easily identified by current strategies. The major obstacle in identifying small mutations is due to the large size of the dystrophin gene. We selectively screened 5 DMD exons containing CpG dinucleotides in 110 DMD patients without detectable deletions or duplications. Nonsenses mutations are frequently due to a C- to -T transition within a CG dinucleotide pair. To screen for the nonsense mutations, we used the heteroduplex method. Utilizing this approach, we identified 2 different nonsense mutations and a single base deletion all occurring in exon 19. This is the first report of a clustering of small mutations in the dystrophin gene.

  2. TCOF1 mutation database: novel mutation in the alternatively spliced exon 6A and update in mutation nomenclature.

    Science.gov (United States)

    Splendore, Alessandra; Fanganiello, Roberto D; Masotti, Cibele; Morganti, Lucas S C; Passos-Bueno, M Rita

    2005-05-01

    Recently, a novel exon was described in TCOF1 that, although alternatively spliced, is included in the major protein isoform. In addition, most published mutations in this gene do not conform to current mutation nomenclature guidelines. Given these observations, we developed an online database of TCOF1 mutations in which all the reported mutations are renamed according to standard recommendations and in reference to the genomic and novel cDNA reference sequences (www.genoma.ib.usp.br/TCOF1_database). We also report in this work: 1) results of the first screening for large deletions in TCOF1 by Southern blot in patients without mutation detected by direct sequencing; 2) the identification of the first pathogenic mutation in the newly described exon 6A; and 3) statistical analysis of pathogenic mutations and polymorphism distribution throughout the gene.

  3. Targeted exon sequencing successfully discovers rare causative genes and clarifies the molecular epidemiology of Japanese deafness patients.

    Science.gov (United States)

    Miyagawa, Maiko; Naito, Takehiko; Nishio, Shin-ya; Kamatani, Naoyuki; Usami, Shin-ichi

    2013-01-01

    Target exon resequencing using Massively Parallel DNA Sequencing (MPS) is a new powerful strategy to discover causative genes in rare Mendelian disorders such as deafness. We attempted to identify genomic variations responsible for deafness by massive sequencing of the exons of 112 target candidate genes. By the analysis of 216randomly selected Japanese deafness patients (120 early-onset and 96 late-detected), who had already been evaluated for common genes/mutations by Invader assay and of which 48 had already been diagnosed, we efficiently identified causative mutations and/or mutation candidates in 57 genes. Approximately 86.6% (187/216) of the patients had at least one mutation. Of the 187 patients, in 69 the etiology of the hearing loss was completely explained. To determine which genes have the greatest impact on deafness etiology, the number of mutations was counted, showing that those in GJB2 were exceptionally higher, followed by mutations in SLC26A4, USH2A, GPR98, MYO15A, COL4A5 and CDH23. The present data suggested that targeted exon sequencing of selected genes using the MPS technology followed by the appropriate filtering algorithm will be able to identify rare responsible genes including new candidate genes for individual patients with deafness, and improve molecular diagnosis. In addition, using a large number of patients, the present study clarified the molecular epidemiology of deafness in Japanese. GJB2 is the most prevalent causative gene, and the major (commonly found) gene mutations cause 30-40% of deafness while the remainder of hearing loss is the result of various rare genes/mutations that have been difficult to diagnose by the conventional one-by-one approach. In conclusion, target exon resequencing using MPS technology is a suitable method to discover common and rare causative genes for a highly heterogeneous monogenic disease like hearing loss.

  4. Dietary selenomethionine increases exon-specific DNA methylation of the p53 gene in rat liver and colon mucosa.

    Science.gov (United States)

    Zeng, Huawei; Yan, Lin; Cheng, Wen-Hsing; Uthus, Eric O

    2011-08-01

    The regulation of site-specific DNA methylation of tumor suppressor genes has been considered as a leading mechanism by which certain nutrients exert their anticancer property. This study was to investigate whether selenium (Se) affects the methylation of globe genomic DNA and the exon-specific p53 gene. Three groups of rats (n = 6-7/group) were fed the AIN-93G basal diet supplemented with 0 [Se deficient (D)], 0.15 [Se adequate (A)], or 4 mg [Se supranutritional (S)] (Se as l-selenomethionine)/kg diet for 104 d, respectively. Rats fed the A or S diet had greater plasma and liver glutathione peroxidase activity, liver thioredoxin reductase activity, and plasma homocysteine concentration than those fed the D diet. However, compared with the A diet, rats fed the S diet did not further increase these Se-dependent enzyme activities or homocysteine concentration. In contrast, Se concentrations in kidney, liver, gastrocnemius muscle, and plasma were increased in a Se-dose-dependent manner. Interestingly, rats fed the S diet had significantly less global liver genomic DNA methylation than those fed the D diet. However, the S diet significantly increased the methylation of the p53 gene (exons 5-8) but not the β-actin gene (exons 2-3) DNA in liver and colon mucosa compared with those fed the D diet. Taken together, long-term Se consumption not only affects selenoprotein enzyme activities, homocysteine, tissue Se concentrations, and global genomic DNA methylation but also increases exon-specific DNA methylation of the p53 gene in a Se-dose-dependent manner in rat liver and colon mucosa.

  5. A novel mutation of WT1 exon 9 in a patient with Denys-Drash syndrome and pyloric stenosis.

    Science.gov (United States)

    Hu, Min; Craig, Jonathon; Howard, Neville; Kan, Alex; Chaitow, Jeffrey; Little, Dianne; Alexander, Stephen I

    2004-10-01

    We report a novel mutation in WT1 exon 9 (1214 A>G) resulting in an amino acid change from H to R at codon 405 in a 46 XY female patient who had congenital hypertrophic pyloric stenosis, pseudohermaphroditism masculinus, renal failure, and Wilms tumor, and died at the age of 22 months. The patient demonstrated the difficulty in diagnosing a patient with intersex before conclusive genetic characterization.

  6. Severe congenital lipodystrophy and a progeroid appearance: Mutation in the penultimate exon of FBN1 causing a recognizable phenotype.

    Science.gov (United States)

    Takenouchi, Toshiki; Hida, Mariko; Sakamoto, Yoshiaki; Torii, Chiharu; Kosaki, Rika; Takahashi, Takao; Kosaki, Kenjiro

    2013-12-01

    Recently, three marfanoid patients with congenital lipodystrophy and a neonatal progeroid appearance were reported. Although their phenotype was distinct from that of classic Marfan syndrome, they all had a truncating mutation in the penultimate exon, i.e., exon 64, of FBN1, the causative gene for Marfan syndrome. These patients might represent a new entity, but the exact phenotypic and genotypic spectrum remains unknown. Here, we report on a girl born prematurely who exhibited severe congenital lipodystrophy and a neonatal progeroid appearance. The patient exhibited a characteristic growth pattern consisting of an accelerated growth in height with a discrepant poor weight gain. She had a characteristic facial appearance with craniosynostosis. A mutation analysis identified c.8175_8182del8bp, p.Arg2726Glufs*9 in exon 64 of the FBN1 gene. A review of similar, recently reported patients revealed that the cardinal features of these patients include (1) congenital lipodystrophy, (2) premature birth with an accelerated linear growth disproportionate to the weight gain, and (3) a progeroid appearance with distinct facial features. Lines of molecular evidence suggested that this new progeroid syndrome represents a neomorphic phenotype caused by truncated transcripts with an extremely charged protein motif that escapes from nonsense-mediated mRNA decay, altering FBN1-TGF beta signaling, rather than representing the severe end of the hypomorphic phenotype of the FBN1-TGF beta disorder spectrum. We propose that this marfanoid entity comprised of congenital lipodystrophy, a neonatal progeroid appearance, and a peculiar growth profile and caused by rare mutations in the penultimate exon of FBN1, be newly referred to as marfanoid-progeroid syndrome.

  7. Biochemical identification of new proteins involved in splicing repression at the Drosophila P-element exonic splicing silencer

    Science.gov (United States)

    Horan, Lucas; Yasuhara, Jiro C.; Kohlstaedt, Lori A.; Rio, Donald C.

    2015-01-01

    Splicing of the Drosophila P-element third intron (IVS3) is repressed in somatic tissues due to the function of an exonic splicing silencer (ESS) complex present on the 5′ exon RNA. To comprehensively characterize the mechanisms of this alternative splicing regulation, we used biochemical fractionation and affinity purification to isolate the silencer complex assembled in vitro and identify the constituent proteins by mass spectrometry. Functional assays using splicing reporter minigenes identified the proteins hrp36 and hrp38 and the cytoplasmic poly(A)-binding protein PABPC1 as novel functional components of the splicing silencer. hrp48, PSI, and PABPC1 have high-affinity RNA-binding sites on the P-element IVS3 5′ exon, whereas hrp36 and hrp38 proteins bind with low affinity to the P-element silencer RNA. RNA pull-down and immobilized protein assays showed that hrp48 protein binding to the silencer RNA can recruit hrp36 and hrp38. These studies identified additional components that function at the P-element ESS and indicated that proteins with low-affinity RNA-binding sites can be recruited in a functional manner through interactions with a protein bound to RNA at a high-affinity binding site. These studies have implications for the role of heterogeneous nuclear ribonucleoproteins (hnRNPs) in the control of alternative splicing at cis-acting regulatory sites. PMID:26545814

  8. Long-term Exon Skipping Studies With 2′-O-Methyl Phosphorothioate Antisense Oligonucleotides in Dystrophic Mouse Models

    Directory of Open Access Journals (Sweden)

    Christa L Tanganyika-de Winter

    2012-01-01

    Full Text Available Antisense-mediated exon skipping for Duchenne muscular dystrophy (DMD is currently tested in phase 3 clinical trials. The aim of this approach is to modulate splicing by skipping a specific exon to reframe disrupted dystrophin transcripts, allowing the synthesis of a partly functional dystrophin protein. Studies in animal models allow detailed analysis of the pharmacokinetic and pharmacodynamic profile of antisense oligonucleotides (AONs. Here, we tested the safety and efficacy of subcutaneously administered 2′-O-methyl phosphorothioate AON at 200 mg/kg/week for up to 6 months in mouse models with varying levels of disease severity: mdx mice (mild phenotype and mdx mice with one utrophin allele (mdx/utrn+/−; more severe phenotype. Long-term treatment was well tolerated and exon skipping and dystrophin restoration confirmed for all animals. Notably, in the more severely affected mdx/utrn+/− mice the therapeutic effect was larger: creatine kinase (CK levels were more decreased and rotarod running time was more increased. This suggests that the mdx/utrn+/− model may be a more suitable model to test potential therapies than the regular mdx mouse. Our results also indicate that long-term subcutaneous treatment in dystrophic mouse models with these AONs is safe and beneficial.

  9. Polymorphism analysis of IGFBP-5 gene exon 1 in Tibet Mini-pig and Junmu No. 1 White pig.

    Science.gov (United States)

    Chen, A; Hao, L L; Fang, X B; Lu, K; Liu, S C; Zhang, Y L

    2014-03-12

    The genetic resources and the mechanism of miniaturization in the Tibet Mini-pig have not been comprehensively studied. Polymorphisms in genes related to the insulin-like growth factor (IGF) axis have been investigated for years, but few on the polymorphism of IGF-binding protein-5 (IGFBP-5) in the Tibetan pig. In this study, allele-specific polymerase chain reaction (AS-PCR) was used to analyze polymorphisms in exon 1 of the IGFBP-5 gene in two pig breeds, Tibet Mini-pigs and Junmu No. 1 White pigs. A BLAST analysis of the expressed sequence tags in the porcine IGFBP-5 gene revealed that exon 1 of this gene has two single nucleotide polymorphisms (SNPs), G188T and G503A. The AS-PCR results demonstrated that in both pig breeds examined, the TT, GT, and GG genotypes existed at the G188T locus, with GT as the most common genotype. At the G503A locus, GG, GA, and AA genotypes existed in Junmu No. 1 White pigs, with the GA genotype as the most frequently occurring. By contrast, at this locus, only the GA and AA genotypes were observed in the Tibetan pigs, and AA was more common than GA. There was a significant difference (P Tibet Mini-pigs than in Junmu No. 1 White pigs. The present study revealed SNPs in exon 1 of IGFBP-5 gene in the Tibet Mini-pig, possibly providing more understanding of the mechanism of miniaturization.

  10. Exons I and VII of the gene (Ker10) encoding human keratin 10 undergo structural rearrangements within repeats.

    Science.gov (United States)

    Tkachenko, A V; Buchman, V L; Bliskovsky, V V; Shvets YuP; Kisselev, L L

    1992-07-15

    A genomic fragment containing the K51 gene previously isolated from a rat genomic library by hybridization with the v-mos probe in nonstringent conditions [Chumakov et al., Dokl. Akad. Nauk SSSR 290 (1986) 1252-1254], resembles a human keratin type-I-encoding gene [Shvets et al., Mol. Biol. 24 (1990) 663-677]. This genomic clone, K51, has been used as a probe to search for related human genes. A recombinant clone, HK51, with a 1.5-kb insert, was isolated from a human embryonic skin cDNA library, and its nucleotide (nt) sequence was determined. Analysis has shown that the cloned cDNA encodes human keratin 10 (Ker10). All presently known nt sequences of the human Ker10-encoding gene (Ker10) are not identical. Differences are concentrated in the 5'-end of the first exon and in the middle of the seventh exon within repeats. In spite of structural rearrangements in two of eight exons, the reading frame and position of the stop codon are preserved. The genetic rearrangements cause changes in hydrophobicity profiles of the N and C termini of Ker10. It was also noticed that insertion of one nt leads to the formation of an unusual 3'-end of the transcript.

  11. Cellular trafficking determines the exon skipping activity of Pip6a-PMO in mdx skeletal and cardiac muscle cells.

    Science.gov (United States)

    Lehto, Taavi; Castillo Alvarez, Alejandra; Gauck, Sarah; Gait, Michael J; Coursindel, Thibault; Wood, Matthew J A; Lebleu, Bernard; Boisguerin, Prisca

    2014-03-01

    Cell-penetrating peptide-mediated delivery of phosphorodiamidate morpholino oligomers (PMOs) has shown great promise for exon-skipping therapy of Duchenne Muscular Dystrophy (DMD). Pip6a-PMO, a recently developed conjugate, is particularly efficient in a murine DMD model, although mechanisms responsible for its increased biological activity have not been studied. Here, we evaluate the cellular trafficking and the biological activity of Pip6a-PMO in skeletal muscle cells and primary cardiomyocytes. Our results indicate that Pip6a-PMO is taken up in the skeletal muscle cells by an energy- and caveolae-mediated endocytosis. Interestingly, its cellular distribution is different in undifferentiated and differentiated skeletal muscle cells (vesicular versus nuclear). Likewise, Pip6a-PMO mainly accumulates in cytoplasmic vesicles in primary cardiomyocytes, in which clathrin-mediated endocytosis seems to be the pre-dominant uptake pathway. These differences in cellular trafficking correspond well with the exon-skipping data, with higher activity in myotubes than in myoblasts or cardiomyocytes. These differences in cellular trafficking thus provide a possible mechanistic explanation for the variations in exon-skipping activity and restoration of dystrophin protein in heart muscle compared with skeletal muscle tissues in DMD models. Overall, Pip6a-PMO appears as the most efficient conjugate to date (low nanomolar EC50), even if limitations remain from endosomal escape.

  12. Polyquaternium-mediated delivery of morpholino oligonucleotides for exon-skipping in vitro and in mdx mice.

    Science.gov (United States)

    Wang, Mingxing; Wu, Bo; Shah, Sapana N; Lu, Peijuan; Lu, Qilong

    2017-11-01

    Antisense oligonucleotide therapy for Duchenne muscular dystrophy has shown great potential in preclinical and clinical trials, but its therapeutic applications are still limited due to inefficient delivery. In this study, we investigated a few polyquaterniums (PQs) with different size and composition for their potential to improve delivery performance of an antisense phosphorodiamidate morpholino oligomer (PMO) both in vitro and in vivo. The results showed that Luviquat(TM) series, especially PQ-1 and PQ-3, promoted the exon-skipping efficiency comparable to Endoporter-mediated PMO delivery in vitro. Significant enhancement in skipping dystrophin exon 23 has also been achieved with PQ-3 up to seven-fold when compared to PMO alone in mdx mice. Cytotoxicity of the PQs was lower than Endoporter and PEI 25 K in vitro and muscle damage not clearly detected in vivo under the tested concentrations. These results together demonstrate that the optimization of PQ in molecular size, composition and distribution of positive charges is the key factor to achieve enhanced PMO exon-skipping efficiency. The higher efficiency and lower toxicity endow polyquaternium series as AO delivery enhancing agents for treating muscular dystrophy and other diseases.

  13. Somatic mosaicism detected by exon-targeted, high-resolution aCGH in 10,362 consecutive cases.

    Science.gov (United States)

    Pham, Justin; Shaw, Chad; Pursley, Amber; Hixson, Patricia; Sampath, Srirangan; Roney, Erin; Gambin, Tomasz; Kang, Sung-Hae L; Bi, Weimin; Lalani, Seema; Bacino, Carlos; Lupski, James R; Stankiewicz, Pawel; Patel, Ankita; Cheung, Sau-Wai

    2014-08-01

    Somatic chromosomal mosaicism arising from post-zygotic errors is known to cause several well-defined genetic syndromes as well as contribute to phenotypic variation in diseases. However, somatic mosaicism is often under-diagnosed due to challenges in detection. We evaluated 10,362 patients with a custom-designed, exon-targeted whole-genome oligonucleotide array and detected somatic mosaicism in a total of 57 cases (0.55%). The mosaicism was characterized and confirmed by fluorescence in situ hybridization (FISH) and/or chromosome analysis. Different categories of abnormal cell lines were detected: (1) aneuploidy, including sex chromosome abnormalities and isochromosomes (22 cases), (2) ring or marker chromosomes (12 cases), (3) single deletion/duplication copy number variations (CNVs) (11 cases), (4) multiple deletion/duplication CNVs (5 cases), (5) exonic CNVs (4 cases), and (6) unbalanced translocations (3 cases). Levels of mosaicism calculated based on the array data were in good concordance with those observed by FISH (10-93%). Of the 14 cases evaluated concurrently by chromosome analysis, mosaicism was detected solely by the array in 4 cases (29%). In summary, our exon-targeted array further expands the diagnostic capability of high-resolution array comparative genomic hybridization in detecting mosaicism for cytogenetic abnormalities as well as small CNVs in disease-causing genes.

  14. Peptide conjugation of 2'-O-methyl phosphorothioate antisense oligonucleotides enhances cardiac uptake and exon skipping in mdx mice.

    Science.gov (United States)

    Jirka, Silvana M G; Heemskerk, Hans; Tanganyika-de Winter, Christa L; Muilwijk, Daan; Pang, Kar Him; de Visser, Peter C; Janson, Anneke; Karnaoukh, Tatyana G; Vermue, Rick; 't Hoen, Peter A C; van Deutekom, Judith C T; Aguilera, Begoña; Aartsma-Rus, Annemieke

    2014-02-01

    Antisense oligonucleotide (AON)-mediated exon skipping is a promising therapeutic approach for Duchenne muscular dystrophy that is currently being tested in various clinical trials. This approach is based on restoring the open reading frame of dystrophin transcripts resulting in shorter but partially functional dystrophin proteins as found in patients with Becker muscular dystrophy. After systemic administration, a large proportion of AONs ends up in the liver and kidneys. Therefore, enhancing AON uptake by skeletal and cardiac muscle would improve the AONs' therapeutic effect. For phosphorodiamidate morpholino oligomer, AONs use nonspecific positively charged cell penetrating peptides to enhance efficacy. However, this is challenging for negatively charged 2'-O-methyl phosphorothioate oligomer. Therefore, we screened a 7-mer phage display peptide library to identify muscle and heart homing peptides in vivo in the mdx mouse model and found a promising candidate peptide capable of binding muscle cells in vitro and in vivo. Upon systemic administration in dystrophic mdx mice, conjugation of a 2'-O-methyl phosphorothioate AON to this peptide indeed improved uptake in skeletal and cardiac muscle, and resulted in higher exon skipping levels with a significant difference in heart and diaphragm. Based on these results, peptide conjugation represents an interesting strategy to enhance the therapeutic effect of exon skipping with 2'-O-methyl phosphorothioate AONs for Duchenne muscular dystrophy.

  15. Cell line OCI/AML3 bears exon-12 NPM gene mutation-A and cytoplasmic expression of nucleophosmin.

    Science.gov (United States)

    Quentmeier, H; Martelli, M P; Dirks, W G; Bolli, N; Liso, A; Macleod, R A F; Nicoletti, I; Mannucci, R; Pucciarini, A; Bigerna, B; Martelli, M F; Mecucci, C; Drexler, H G; Falini, B

    2005-10-01

    We recently identified a new acute myeloid leukemia (AML) subtype characterized by mutations at exon-12 of the nucleophosmin (NPM) gene and aberrant cytoplasmic expression of NPM protein (NPMc+). NPMc+ AML accounts for about 35% of adult AML and it is associated with normal karyotype, wide morphological spectrum, CD34-negativity, high frequency of FLT3-ITD mutations and good response to induction therapy. In an attempt to identify a human cell line to serve as a model for the in vitro study of NPMc+ AML, we screened 79 myeloid cell lines for mutations at exon-12 of NPM. One of these cell lines, OCI/AML3, showed a TCTG duplication at exon-12 of NPM. This mutation corresponds to the type A, the NPM mutation most frequently observed in primary NPMc+ AML. OCI/AML3 cells also displayed typical phenotypic features of NPMc+ AML, that is, expression of macrophage markers and lack of CD34, and the immunocytochemical hallmark of this leukemia subtype, that is, the aberrant cytoplasmic expression of NPM. The OCI/AML3 cell line easily engrafts in NOD/SCID mice and maintains in the animals the typical features of NPMc+ AML, such as the NPM cytoplasmic expression. For all these reasons, the OCI/AML3 cell line represents a remarkable tool for biomolecular studies of NPMc+ AML.

  16. Predominant RET Germline Mutations in Exons 10, 11, and 16 in Iranian Patients with Hereditary Medullary Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Mehdi Hedayati

    2011-01-01

    Full Text Available Medullary thyroid carcinoma occurs in both sporadic (75% and hereditary (25% forms. The missense mutations of RET proto-oncogene in MTC development have been well demonstrated. To investigate the spectrum of predominant RET germline mutations in exons 10, 11, and 16 in hereditary MTC in Iranian population, 217 participants were included. Genomic DNAs were extracted from the leukocytes using the standard Salting Out/Proteinase K method. Mutation detection was performed through PCR-RFLP and DNA sequencing. In 217 participants, 43 missense mutations were identified in exons 10 (6%, 11 (13%, and 16 (0.9%. Moreover, a novel germline mutation was detected in exon 11 (S686N. Also four different polymorphisms were found in intron 16 in eight patients. The obtained data showed the frequency profile of RET mutations in Iranian individuals with MTC (19.8%. The most frequent mutation in our population was C634G whereas in most population it was C634R. Altogether, these results underline the importance of the genetic background of family members of any patient with MTC.

  17. Novel P2 promoter-derived HNF4{alpha} isoforms with different N-terminus generated by alternate exon insertion

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jianmin, E-mail: jmhuang@partners.org [Pediatric Endocrine Unit, MassGeneral Hospital for Children and Harvard Medical School, Boston, Massachusetts, 02114-2696 (United States); Levitsky, Lynne L. [Pediatric Endocrine Unit, MassGeneral Hospital for Children and Harvard Medical School, Boston, Massachusetts, 02114-2696 (United States); Rhoads, David B., E-mail: rhoads@helix.mgh.harvard.edu [Pediatric Endocrine Unit, MassGeneral Hospital for Children and Harvard Medical School, Boston, Massachusetts, 02114-2696 (United States)

    2009-04-15

    Hepatocyte nuclear factor 4{alpha} (HNF4{alpha}) is a critical transcription factor for pancreas and liver development and functions in islet {beta} cells to maintain glucose homeostasis. Mutations in the human HNF4A gene lead to maturity onset diabetes of the young (MODY1) and polymorphisms are associated with increased risk for type 2 diabetes mellitus (T2DM). Expression of six HNF4{alpha} variants, three each from two developmentally regulated promoters, has been firmly established. We have now detected a new set of HNF4{alpha} variants designated HNF4{alpha}10-12 expressed from distal promoter P2. These variants, generated by inclusion of previously undetected exon 1E (human = 222 nt, rodent = 136 nt) following exon 1D have an altered N-terminus but identical remaining reading frame. HNF4{alpha}10-{alpha}12 are expressed in pancreatic islets (and liver) and exhibit transactivation potentials similar to the corresponding {alpha}7-{alpha}9 isoforms. DNA-binding analyses implied much higher protein levels of HNF4{alpha}10-{alpha}12 in liver than expected from the RT-PCR data. Our results provide evidence for a more complex expression pattern of HNF4{alpha} than previously appreciated. We recommend inclusion of exon 1E and nearby DNA sequences in screening for HNF4{alpha} mutations and polymorphisms in genetic analyses of MODY1 and T2DM.

  18. De novo disruption of promoter and exon 1 of STAR gene reveals essential role for gonadal development

    Directory of Open Access Journals (Sweden)

    Anil Piya

    2017-03-01

    Full Text Available Cholesterol transport into the mitochondria is required for synthesis of the first steroid, pregnenolone. Cholesterol is transported by the steroidogenic acute regulatory protein (STAR, which acts at the outer mitochondrial membrane prior to its import. Mutations in the STAR protein result in lipoid congenital adrenal hyperplasia (CAH. Although the STAR protein consists of seven exons, biochemical analysis in nonsteroidogenic COS-1 cells showed that the first two were not essential for pregnenolone synthesis. Here, we present a patient with ambiguous genitalia, salt-lossing crisis within two weeks after birth and low cortisol levels. Sequence analysis of the STAR, including the exon–intron boundaries, showed the complete deletion of exon 1 as well as more than 50 nucleotides upstream of STAR promoter. Mitochondrial protein import with the translated protein through synthesis cassette of the mutant STAR lacking exon 1 showed protein translation, but it is less likely to have synthesized without a promoter in our patient. Thus, a full-length STAR gene is necessary for physiological mitochondrial cholesterol transport in vivo.

  19. A new chromosome x exon-specific microarray platform for screening of patients with X-linked disorders.

    Science.gov (United States)

    Bashiardes, Stavros; Kousoulidou, Ludmila; van Bokhoven, Hans; Ropers, Hans-Hilger; Chelly, Jamel; Moraine, Claude; de Brouwer, Arjan P M; Van Esch, Hilde; Froyen, Guy; Patsalis, Philippos C

    2009-11-01

    Recent studies and advances in high-density oligonucleotide arrays have shown that microdeletions and microduplications occur at a high frequency in the human genome, causing various genetic conditions including mental retardation. Thus far little is known about the pathways leading to this disease, and implementation of microarrays is hampered by their increasing cost and complexity, underlining the need for new diagnostic tools. The aim of this study was to introduce a new targeted platform called "chromosome X exon-specific array" and to apply this new platform to screening of 20 families (including one blind positive control) with suspected X-linked mental retardation, to identify new causative X-linked mental retardation genes. The new microarray contains of 21,939 oligonucleotides covering 92.9% of all exons of all genes on chromosome X. Patient screening resulted in successful identification of the blind positive control included in the sample of 20 families, and one of the remaining 19 families was found to carry a 1.78-kilobase deletion involving all exons of pseudogene BRAF2. The BRAF2 deletion segregated in the family and was not found in 200 normal male samples, and no copy number variations are reported in this region. Further studies and focused investigation of X-linked disorders have the potential to reveal the molecular basis of human genetic pathological conditions that are caused by copy-number changes in chromosome X genes.

  20. Polymorphisms of Exon 17 of Insulin-Receptor Gene in Pathogenesis of Human Disorders With Insulin Resistance

    Institute of Scientific and Technical Information of China (English)

    LU WANG; JIE MI; XIAO-YUAN ZHAO; JIAN-XIN WU; HONG CHENG; ZHI-KUN ZHANG; XIU-YUAN DING; DONG-QING HOU; HUILI

    2004-01-01

    To investigate the relationship between polymorphisms of insulin-receptor (INSR) gene and insulin resistance in a population-based study in China. Methods Polymerase Chain Reaction (PCR) was used to the amplify Exon 17 of INSR gene and all amplified products were analyzed by direct sequencing. Results Six single-nucleotide polymorphisms (SNPs) were found at the following loci: T to TC at the locus of 10699 (Tyr984), G to GC at the locus of 10731 (Glu994), Deletion G at the locus of 10798 (Asp1017), C to T/TC at the locus of 10923 (His1058), C to CA at the locus of 10954 (Leu1069), and T to TA at the locus of 10961 (Phe1071), which might not change the amino acid sequence. The data were in agreement with the test of Hardy-Weinberg balance (P>0.05). Among the 345 cases, all clinical indices were higher in males than in females except for HDL cholesterol (P0.05). After sex stratification in analysis,all allele frequencies on the six loci of SNPs of Exon 17 had different distributions between the insulin resistant group and the control group, but P>0.05. Conclusion SNPs of Exon 17 of INSR gene are unlikely to play a direct role in the pathogenesis of human disorders with insulin resistance.

  1. Somatic mosaicism detected by exon-targeted, high-resolution aCGH in 10 362 consecutive cases

    Science.gov (United States)

    Pham, Justin; Shaw, Chad; Pursley, Amber; Hixson, Patricia; Sampath, Srirangan; Roney, Erin; Gambin, Tomasz; Kang, Sung-Hae L; Bi, Weimin; Lalani, Seema; Bacino, Carlos; Lupski, James R; Stankiewicz, Pawel; Patel, Ankita; Cheung, Sau-Wai

    2014-01-01

    Somatic chromosomal mosaicism arising from post-zygotic errors is known to cause several well-defined genetic syndromes as well as contribute to phenotypic variation in diseases. However, somatic mosaicism is often under-diagnosed due to challenges in detection. We evaluated 10 362 patients with a custom-designed, exon-targeted whole-genome oligonucleotide array and detected somatic mosaicism in a total of 57 cases (0.55%). The mosaicism was characterized and confirmed by fluorescence in situ hybridization (FISH) and/or chromosome analysis. Different categories of abnormal cell lines were detected: (1) aneuploidy, including sex chromosome abnormalities and isochromosomes (22 cases), (2) ring or marker chromosomes (12 cases), (3) single deletion/duplication copy number variations (CNVs) (11 cases), (4) multiple deletion/duplication CNVs (5 cases), (5) exonic CNVs (4 cases), and (6) unbalanced translocations (3 cases). Levels of mosaicism calculated based on the array data were in good concordance with those observed by FISH (10–93%). Of the 14 cases evaluated concurrently by chromosome analysis, mosaicism was detected solely by the array in 4 cases (29%). In summary, our exon-targeted array further expands the diagnostic capability of high-resolution array comparative genomic hybridization in detecting mosaicism for cytogenetic abnormalities as well as small CNVs in disease-causing genes. PMID:24398791

  2. Analysis of the functional consequences of targeted exon deletion in COL7A1 reveals prospects for dystrophic epidermolysis bullosa therapy

    NARCIS (Netherlands)

    Bornert, Olivier; Kuhl, Tobias; Bremer, Jeroen; van den Akker, Peter C.; Pasmooij, Anna M. G.; Nystrom, Alexander

    2016-01-01

    Genetically evoked deficiency of collagen VII causes dystrophic epidermolysis bullosa (DEB)-a debilitating disease characterized by chronic skin fragility and progressive fibrosis. Removal of exons carrying frame-disrupting mutations can reinstate protein expression in genetic diseases. The therapeu

  3. Occipital horn syndrome and classical Menkes syndrome caused by deep intronic mutations, leading to the activation of ATP7A pseudo-exon

    DEFF Research Database (Denmark)

    Yasmeen, Saiqa; Lund, Katrine; De Paepe, Anne

    2014-01-01

    Menkes disease is an X-linked disorder of copper metabolism caused by mutations in the ATP7A gene. Whereas most of the patients exhibit a severe classical form, about 9% of the patients exhibit a milder form of Menkes disease. The mildest form is called occipital horn syndrome (OHS). Mutations...... patients: two patients with OHS and one patient with classical Menkes disease. The pseudo-exons were inserted between exons 10 and 11, between exons 16 and 17 and between exons 14 and 15 in the three patients, as a result of deep intronic mutations. This is the first time the activation of pseudo...... mechanism, which has hitherto been overlooked.European Journal of Human Genetics advance online publication, 4 September 2013; doi:10.1038/ejhg.2013.191....

  4. Missense mutations in FBN1 exons 41 and 42 cause Weill-Marchesani syndrome with thoracic aortic disease and Marfan syndrome.

    Science.gov (United States)

    Cecchi, Alana; Ogawa, Naomi; Martinez, Hugo R; Carlson, Alicia; Fan, Yuxin; Penny, Daniel J; Guo, Dong-chuan; Eisenberg, Steven; Safi, Hazim; Estrera, Anthony; Lewis, Richard A; Meyers, Deborah; Milewicz, Dianna M

    2013-09-01

    Mutations in FBN1 cause a range of overlapping but distinct conditions including Marfan syndrome (MFS), Weill-Marchesani syndrome (WMS), familial thoracic aortic aneurysms/dissections (FTAAD), acromicric dysplasia (AD), and geleophysic dysplasia (GD). Two forms of acromelic dysplasia, AD and GD, characterized by short stature, brachydactyly, reduced joint mobility, and characteristic facies, result from heterozygous missense mutations occurring in exons 41 and 42 of FBN1; missense mutations in these exons have not been reported to cause MFS or other syndromes. Here we report on probands with MFS and WMS who have heterozygous FBN1 missense mutations in exons 41 and 42, respectively. The proband with WMS has ectopia lentis, short stature, thickened pinnae, tight skin, striae atrophicae, reduced extension of the elbows, contractures of the fingers and toes, and brachydactyly and has a missense mutation in exon 42 of FBN1 (c.5242T>C; p.C1748R). He also experienced a previously unreported complication of WMS, an acute thoracic aortic dissection. The second proband displays classic characteristics of MFS, including ectopia lentis, skeletal features, and aortic root dilatation, and has a missense mutation in exon 41 of FBN1 (c.5084G>A; p.C1695Y). These phenotypes provide evidence that missense mutations in exons 41 and 42 of FBN1 lead to MFS and WMS in addition to AD and GD and also suggest that all individuals with pathogenic FBN1 mutations in these exons should be assessed for thoracic aortic disease and ectopia lentis. Further studies are necessary to elucidate the factors responsible for the different phenotypes associated with missense mutations in these exons of FBN1.

  5. The relationship between MHC-DRB1 gene second exon polymorphism and hydatidosis resistance of Chinese merino (Sinkiang Junken type), Kazakh and Duolang sheep

    OpenAIRE

    Li R.Y.; Hui W.Q.; Jia B; Shi G.Q.; Zhao Z.S.; Shen H.; Peng Q; Lv L.M.; Zhou Q.W.; Li H.T.

    2011-01-01

    The present study aimed at detecting the association of ovine major histocompatibility complex class II (Ovar II) DRB1 gene second exon and susceptibility or resistance to hydatidosis in three sheep breeds of Sinkiang. The MHC-DRB1 second exon was amplified by polymerase chain reaction (PCR) from DNA samples of healthy sheep and sheep with hydatidosis. PCR products were characterized by the restriction fragment length polymorphism (RFLP) technique. Five restriction enzymes, MvaI, HaeIII, SacI...

  6. Evolution of hydra, a recently evolved testis-expressed gene with nine alternative first exons in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Shou-Tao Chen

    2007-07-01

    Full Text Available We describe here the Drosophila gene hydra that appears to have originated de novo in the melanogaster subgroup and subsequently evolved in both structure and expression level in Drosophila melanogaster and its sibling species. D. melanogaster hydra encodes a predicted protein of approximately 300 amino acids with no apparent similarity to any previously known proteins. The syntenic region flanking hydra on both sides is found in both D. ananassae and D. pseudoobscura, but hydra is found only in melanogaster subgroup species, suggesting that it originated less than approximately 13 million y ago. Exon 1 of hydra has undergone recurrent duplications, leading to the formation of nine tandem alternative exon 1s in D. melanogaster. Seven of these alternative exons are flanked on their 3' side by the transposon DINE-1 (Drosophila interspersed element-1. We demonstrate that at least four of the nine duplicated exon 1s can function as alternative transcription start sites. The entire hydra locus has also duplicated in D. simulans and D. sechellia. D. melanogaster hydra is expressed most intensely in the proximal testis, suggesting a role in late-stage spermatogenesis. The coding region of hydra has a relatively high Ka/Ks ratio between species, but the ratio is less than 1 in all comparisons, suggesting that hydra is subject to functional constraint. Analysis of sequence polymorphism and divergence of hydra shows that it has evolved under positive selection in the lineage leading to D. melanogaster. The dramatic structural changes surrounding the first exons do not affect the tissue specificity of gene expression: hydra is expressed predominantly in the testes in D. melanogaster, D. simulans, and D. yakuba. However, we have found that expression level changed dramatically (approximately >20-fold between D. melanogaster and D. simulans. While hydra initially evolved in the absence of nearby transposable element insertions, we suggest that the subsequent

  7. Hereditary vitamin D resistant rickets due to deletion of exon 3 of the vitamin D receptor

    Energy Technology Data Exchange (ETDEWEB)

    Rut, A.R.; O`Riordan, J.L.H.; Hughes, M.R. [Baylor College of Medicine, Houston, TX (United States)

    1994-09-01

    Hereditary vitamin D resistant rickets is an autosomal recessive disorder characterized by severe rickets, hypolcalcaemia, secondary hyperparathyroidism and occasionally, the absence of body hair. The pathological process involves resistance of target tissues to the actions of calcitriol [1,25(OH{sub 2}D{sub 3})], the hormonal form of vitamin D. Calcitriol mediates its actions through a nuclear receptor (VDR) which has been cloned and shown to be a member of the superfamily of steriod/thyroid/retinoic acid receptors. Skin fibroblasts were obtained from a Greek child with characteristic features of the condition. Total RNA was extracted from rapidly dividing cells and reverse transcribed. The coding region was amplified by PCR with primers 31a in the 5{prime} untranslated region and 31b in the 3{prime} untranslated region of the VDR cDNA sequence. The 5{prime} and 3{prime} halves of VDR were further amplified using primers tagged with M13 forward and reverse primer sequences. The whole process was carried out in duplicate starting with RNA. Sequence data was obtained using Taq dye primer cycle sequencing (ABI). Agarose gel electrophoresis revealed that the 5{prime} product was approximately 100 bp shorter than control. This was confirmed by sequencing which demonstrated a 131 bp deletion of the C-terminal part of the DNA binding domain (bases 147-277). Bases 147-277 are coded for by exon 3 and this deletion is bounded by the splice junctions. This is the first report of a deletion in VDR in any patient with vitamin D-resistant rickets. Such a deletion not only removes the second zinc finger but also results in a frameshift that corrupts the remainder of the receptor. Such a deletion may have arisen as a result of a microdeletion of genomic DNA or, more likely, as a result of defective splicing.

  8. Rare exonic minisatellite alleles in MUC2 influence susceptibility to gastric carcinoma.

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    Yun Hee Jeong

    Full Text Available BACKGROUND: Mucins are the major components of mucus and their genes share a common, centrally-located region of sequence that encodes tandem repeats. Mucins are well known genes with respect to their specific expression levels; however, their genomic levels are unclear because of complex genomic properties. In this study, we identified eight novel minisatellites from the entire MUC2 region and investigated how allelic variation in these minisatellites may affect susceptibility to gastrointestinal cancer. METHODOLOGY/PRINCIPLE FINDINGS: We analyzed genomic DNA from the blood of normal healthy individuals and multi-generational family groups. Six of the eight minisatellites exhibited polymorphism and were transmitted meiotically in seven families, following Mendelian inheritance. Furthermore, a case-control study was performed that compared genomic DNA from 457 cancer-free controls with DNA from individuals with gastric (455, colon (192 and rectal (271 cancers. A statistically significant association was identified between rare exonic MUC2-MS6 alleles and the occurrence of gastric cancer: odds ratio (OR, 2.56; 95% confidence interval (CI, 1.31-5.04; and p = 0.0047. We focused on an association between rare alleles and gastric cancer. Rare alleles were divided into short (40, 43 and 44 and long (47, 50 and 54, according to their TR (tandem repeats lengths. Interestingly, short rare alleles were associated with gastric cancer (OR = 5.6, 95% CI: 1.93-16.42; p = 0.00036. Moreover, hypervariable MUC2 minisatellites were analyzed in matched blood and cancer tissue from 28 patients with gastric cancer and in 4 cases of MUC2-MS2, minisatellites were found to have undergone rearrangement. CONCLUSIONS/SIGNIFICANCE: Our observations suggest that the short rare MUC2-MS6 alleles could function as identifiers for risk of gastric cancer. Additionally, we suggest that minisatellite instability might be associated with MUC2 function in cancer cells.

  9. A TALEN-Exon Skipping Design for a Bethlem Myopathy Model in Zebrafish.

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    Zlatko Radev

    Full Text Available Presently, human collagen VI-related diseases such as Ullrich congenital muscular dystrophy (UCMD and Bethlem myopathy (BM remain incurable, emphasizing the need to unravel their etiology and improve their treatments. In UCMD, symptom onset occurs early, and both diseases aggravate with ageing. In zebrafish fry, morpholinos reproduced early UCMD and BM symptoms but did not allow to study the late phenotype. Here, we produced the first zebrafish line with the human mutation frequently found in collagen VI-related disorders such as UCMD and BM. We used a transcription activator-like effector nuclease (TALEN to design the col6a1ama605003-line with a mutation within an essential splice donor site, in intron 14 of the col6a1 gene, which provoke an in-frame skipping of exon 14 in the processed mRNA. This mutation at a splice donor site is the first example of a template-independent modification of splicing induced in zebrafish using a targetable nuclease. This technique is readily expandable to other organisms and can be instrumental in other disease studies. Histological and ultrastructural analyzes of homozygous and heterozygous mutant fry and 3 months post-fertilization (mpf fish revealed co-dominantly inherited abnormal myofibers with disorganized myofibrils, enlarged sarcoplasmic reticulum, altered mitochondria and misaligned sarcomeres. Locomotion analyzes showed hypoxia-response behavior in 9 mpf col6a1 mutant unseen in 3 mpf fish. These symptoms worsened with ageing as described in patients with collagen VI deficiency. Thus, the col6a1ama605003-line is the first adult zebrafish model of collagen VI-related diseases; it will be instrumental both for basic research and drug discovery assays focusing on this type of disorders.

  10. High resolution profiling of human exon methylation by liquid hybridization capture-based bisulfite sequencing

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    Wang Junwen

    2011-12-01

    Full Text Available Abstract Background DNA methylation plays important roles in gene regulation during both normal developmental and disease states. In the past decade, a number of methods have been developed and applied to characterize the genome-wide distribution of DNA methylation. Most of these methods endeavored to screen whole genome and turned to be enormously costly and time consuming for studies of the complex mammalian genome. Thus, they are not practical for researchers to study multiple clinical samples in biomarker research. Results Here, we display a novel strategy that relies on the selective capture of target regions by liquid hybridization followed by bisulfite conversion and deep sequencing, which is referred to as liquid hybridization capture-based bisulfite sequencing (LHC-BS. To estimate this method, we utilized about 2 μg of native genomic DNA from YanHuang (YH whole blood samples and a mature dendritic cell (mDC line, respectively, to evaluate their methylation statuses of target regions of exome. The results indicated that the LHC-BS system was able to cover more than 97% of the exome regions and detect their methylation statuses with acceptable allele dropouts. Most of the regions that couldn't provide accurate methylation information were distributed in chromosomes 6 and Y because of multiple mapping to those regions. The accuracy of this strategy was evaluated by pair-wise comparisons using the results from whole genome bisulfite sequencing and validated by bisulfite specific PCR sequencing. Conclusions In the present study, we employed a liquid hybridisation capture system to enrich for exon regions and then combined with bisulfite sequencing to examine the methylation statuses for the first time. This technique is highly sensitive and flexible and can be applied to identify differentially methylated regions (DMRs at specific genomic locations of interest, such as regulatory elements or promoters.

  11. Exon expression in lymphoblastoid cell lines from subjects with schizophrenia before and after glucose deprivation

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    Martin Maureen V

    2009-09-01

    Full Text Available Abstract Background The purpose of this study was to examine the effects of glucose reduction stress on lymphoblastic cell line (LCL gene expression in subjects with schizophrenia compared to non-psychotic relatives. Methods LCLs were grown under two glucose conditions to measure the effects of glucose reduction stress on exon expression in subjects with schizophrenia compared to unaffected family member controls. A second aim of this project was to identify cis-regulated transcripts associated with diagnosis. Results There were a total of 122 transcripts with significant diagnosis by probeset interaction effects and 328 transcripts with glucose deprivation by probeset interaction probeset effects after corrections for multiple comparisons. There were 8 transcripts with expression significantly affected by the interaction between diagnosis and glucose deprivation and probeset after correction for multiple comparisons. The overall validation rate by qPCR of 13 diagnosis effect genes identified through microarray was 62%, and all genes tested by qPCR showed concordant up- or down-regulation by qPCR and microarray. We assessed brain gene expression of five genes found to be altered by diagnosis and glucose deprivation in LCLs and found a significant decrease in expression of one gene, glutaminase, in the dorsolateral prefrontal cortex (DLPFC. One SNP with previously identified regulation by a 3' UTR SNP was found to influence IRF5 expression in both brain and lymphocytes. The relationship between the 3' UTR rs10954213 genotype and IRF5 expression was significant in LCLs (p = 0.0001, DLPFC (p = 0.007, and anterior cingulate cortex (p = 0.002. Conclusion Experimental manipulation of cells lines from subjects with schizophrenia may be a useful approach to explore stress related gene expression alterations in schizophrenia and to identify SNP variants associated with gene expression.

  12. Missense mutation in exon 2 of SLC36A1 responsible for champagne dilution in horses.

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    Deborah Cook

    2008-09-01

    Full Text Available Champagne coat color in horses is controlled by a single, autosomal-dominant gene (CH. The phenotype produced by this gene is valued by many horse breeders, but can be difficult to distinguish from the effect produced by the Cream coat color dilution gene (CR. Three sires and their families segregating for CH were tested by genome scanning with microsatellite markers. The CH gene was mapped within a 6 cM region on horse chromosome 14 (LOD = 11.74 for theta = 0.00. Four candidate genes were identified within the region, namely SPARC [Secreted protein, acidic, cysteine-rich (osteonectin], SLC36A1 (Solute Carrier 36 family A1, SLC36A2 (Solute Carrier 36 family A2, and SLC36A3 (Solute Carrier 36 family A3. SLC36A3 was not expressed in skin tissue and therefore not considered further. The other three genes were sequenced in homozygotes for CH and homozygotes for the absence of the dilution allele (ch. SLC36A1 had a nucleotide substitution in exon 2 for horses with the champagne phenotype, which resulted in a transition from a threonine amino acid to an arginine amino acid (T63R. The association of the single nucleotide polymorphism (SNP with the champagne dilution phenotype was complete, as determined by the presence of the nucleotide variant among all 85 horses with the champagne dilution phenotype and its absence among all 97 horses without the champagne phenotype. This is the first description of a phenotype associated with the SLC36A1 gene.

  13. Upstream ORF affects MYCN translation depending on exon 1b alternative splicing

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    Tutrone Giovani

    2009-12-01

    Full Text Available Abstract Background The MYCN gene is transcribed into two major mRNAs: one full-length (MYCN and one exon 1b-spliced (MYCNΔ1b mRNA. But nothing is known about their respective ability to translate the MYCN protein. Methods Plasmids were prepared to enable translation from the upstream (uORF and major ORF of the two MYCN transcripts. Translation was studied after transfection in neuroblastoma SH-EP cell line. Impact of the upstream AUG on translation was evaluated after directed mutagenesis. Functional study with the two MYCN mRNAs was conducted by a cell viability assay. Existence of a new protein encoded by the MYCNΔ1b uORF was explored by designing a rabbit polyclonal antibody against a specific epitope of this protein. Results Both are translated, but higher levels of protein were seen with MYCNΔ1b mRNA. An upstream ORF was shown to have positive cis-regulatory activity on translation from MYCN but not from MYCNΔ1b mRNA. In transfected SH-EP neuroblastoma cells, high MYCN dosage obtained with MYCNΔ1b mRNA translation induces an antiapoptotic effect after serum deprivation that was not observed with low MYCN expression obtained with MYCN mRNA. Here, we showed that MYCNOT: MYCN Overlap Transcript, a new protein of unknown function is translated from the upstream AUG of MYCNΔ1b mRNA. Conclusions Existence of upstream ORF in MYCN transcripts leads to a new level of MYCN regulation. The resulting MYCN dosage has a weak but significant anti-apoptotic activity after intrinsic apoptosis induction.

  14. Synthesis of a Morpholino Nucleic Acid (MNA-Uridine Phosphoramidite, and Exon Skipping Using MNA/2′-O-Methyl Mixmer Antisense Oligonucleotide

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    Suxiang Chen

    2016-11-01

    Full Text Available In this study, we synthesised a morpholino nucleoside-uridine (MNA-U phosphoramidite and evaluated the potential of a MNA-modified antisense oligonucleotide (AO sequences to induce exon 23 skipping in mdx mouse myotubes in vitro towards extending the applicability of morpholino chemistry with other nucleotide monomers. We designed, synthesised, and compared exon skipping efficiencies of 20 mer MNA-modified 2′-O-methyl RNA mixmer AO on a phosphorothioate backbone (MNA/2′-OMePS to the corresponding fully modified 2′-O-methyl RNA AO (2′-OMePS as a control. Our results showed that the MNA/2′-OMePS efficiently induced exon 23 skipping. As expected, the 2′-OMePS AO control yielded efficient exon 23 skipping. Under the applied conditions, both the AOs showed minor products corresponding to exon 22/23 dual exon skipping in low yield. As these are very preliminary data, more detailed studies are necessary; however, based on the preliminary results, MNA nucleotides might be useful in constructing antisense oligonucleotides.

  15. No role for estrogen receptor 1 gene intron 1 Pvu II and exon 4 C325G polymorphisms in migraine susceptibility

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    Quinlan Sharon

    2006-02-01

    Full Text Available Abstract Background We have previously reported an association between the estrogen receptor 1 (ESR1 gene exon 8 G594A polymorphism and migraine susceptibility in two independent Australian cohorts. In this paper we report results of analysis of two further single nucleotide polymorphisms (SNPs in the ESR1 gene in the same study group, the T/C Pvu II SNP in intron 1 and the C325G SNP in exon 4, as well as results of linkage disequilibrium (LD analysis on these markers. Methods We investigated these variants by case-control association analysis in a cohort of 240 migraineurs and 240 matched controls. The SNPs were genotyped using specific restriction enzyme assays. Results were analysed using contingency table methods incorporating the chi-squared statistic. LD results are presented as D' statistics with associated P values. Results We found no evidence for association of the Pvu II T/C polymorphism and the C325G polymorphism and migraine susceptibility and no evidence for LD between these two SNPs and the previously implicated exon 8 G594A marker. Conclusion We have found no role for the polymorphisms in intron 1 and exon 4 with migraine susceptibility. To further investigate our previously implicated exon 8 marker, we suggest the need for studies with a high density of polymorphisms be undertaken, with particular focus on markers in LD with the exon 8 marker.

  16. Global analysis of physical and functional RNA targets of hnRNP L reveals distinct sequence and epigenetic features of repressed and enhanced exons.

    Science.gov (United States)

    Cole, Brian S; Tapescu, Iulia; Allon, Samuel J; Mallory, Michael J; Qiu, Jinsong; Lake, Robert J; Fan, Hua-Ying; Fu, Xiang-Dong; Lynch, Kristen W

    2015-12-01

    HnRNP L is a ubiquitous splicing-regulatory protein that is critical for the development and function of mammalian T cells. Previous work has identified a few targets of hnRNP L-dependent alternative splicing in T cells and has described transcriptome-wide association of hnRNP L with RNA. However, a comprehensive analysis of the impact of hnRNP L on mRNA expression remains lacking. Here we use next-generation sequencing to identify transcriptome changes upon depletion of hnRNP L in a model T-cell line. We demonstrate that hnRNP L primarily regulates cassette-type alternative splicing, with minimal impact of hnRNP L depletion on transcript abundance, intron retention, or other modes of alternative splicing. Strikingly, we find that binding of hnRNP L within or flanking an exon largely correlates with exon repression by hnRNP L. In contrast, exons that are enhanced by hnRNP L generally lack proximal hnRNP L binding. Notably, these hnRNP L-enhanced exons share sequence and context features that correlate with poor nucleosome positioning, suggesting that hnRNP may enhance inclusion of a subset of exons via a cotranscriptional or epigenetic mechanism. Our data demonstrate that hnRNP L controls inclusion of a broad spectrum of alternative cassette exons in T cells and suggest both direct RNA regulation as well as indirect mechanisms sensitive to the epigenetic landscape.

  17. Mutation in the U2 snRNA influences exon interactions of U5 snRNA loop 1 during pre-mRNA splicing.

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    McGrail, Joanne C; Tatum, Elaine M; O'Keefe, Raymond T

    2006-08-23

    The U2 and U6 snRNAs contribute to the catalysis of intron removal while U5 snRNA loop 1 holds the exons for ligation during pre-mRNA splicing. It is unclear how different exons are positioned precisely with U5 loop 1. Here, we investigate the role of U2 and U6 in positioning the exons with U5 loop 1. Reconstitution in vitro of spliceosomes with mutations in U2 allows U5-pre-mRNA interactions before the first step of splicing. However, insertion in U2 helix Ia disrupts U5-exon interactions with the intron lariat-3' exon splicing intermediate. Conversely, U6 helix Ia insertions prevent U5-pre-mRNA interactions before the first step of splicing. In vivo, synthetic lethal interactions have been identified between U2 insertion and U5 loop 1 insertion mutants. Additionally, analysis of U2 insertion mutants in vivo reveals that they influence the efficiency, but not the accuracy of splicing. Our data suggest that U2 aligns the exons with U5 loop 1 for ligation during the second step of pre-mRNA splicing.

  18. CELF family RNA-binding protein UNC-75 regulates two sets of mutually exclusive exons of the unc-32 gene in neuron-specific manners in Caenorhabditis elegans.

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    Hidehito Kuroyanagi

    Full Text Available An enormous number of alternative pre-mRNA splicing patterns in multicellular organisms are coordinately defined by a limited number of regulatory proteins and cis elements. Mutually exclusive alternative splicing should be strictly regulated and is a challenging model for elucidating regulation mechanisms. Here we provide models of the regulation of two sets of mutually exclusive exons, 4a-4c and 7a-7b, of the Caenorhabditis elegans uncoordinated (unc-32 gene, encoding the a subunit of V0 complex of vacuolar-type H(+-ATPases. We visualize selection patterns of exon 4 and exon 7 in vivo by utilizing a trio and a pair of symmetric fluorescence splicing reporter minigenes, respectively, to demonstrate that they are regulated in tissue-specific manners. Genetic analyses reveal that RBFOX family RNA-binding proteins ASD-1 and FOX-1 and a UGCAUG stretch in intron 7b are involved in the neuron-specific selection of exon 7a. Through further forward genetic screening, we identify UNC-75, a neuron-specific CELF family RNA-binding protein of unknown function, as an essential regulator for the exon 7a selection. Electrophoretic mobility shift assays specify a short fragment in intron 7a as the recognition site for UNC-75 and demonstrate that UNC-75 specifically binds via its three RNA recognition motifs to the element including a UUGUUGUGUUGU stretch. The UUGUUGUGUUGU stretch in the reporter minigenes is actually required for the selection of exon 7a in the nervous system. We compare the amounts of partially spliced RNAs in the wild-type and unc-75 mutant backgrounds and raise a model for the mutually exclusive selection of unc-32 exon 7 by the RBFOX family and UNC-75. The neuron-specific selection of unc-32 exon 4b is also regulated by UNC-75 and the unc-75 mutation suppresses the Unc phenotype of the exon-4b-specific allele of unc-32 mutants. Taken together, UNC-75 is the neuron-specific splicing factor and regulates both sets of the mutually exclusive

  19. Single base mutation in the pro. alpha. 2(I) collagen gene that causes efficient splicing of RNA from exon 27 to exon 29 and synthesis of a shortened but in-frame pro. alpha. 2(I) chain

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    Tromp, G.; Prockop, D.J. (Thomas Jefferson Univ., Philadelphia, PA (USA))

    1988-07-01

    Previous observations demonstrated that a lethal variant of osteogenesis imperfecta had two altered alleles for pro{alpha}2(I) chains of type I procollagen. One mutation produced a nonfunctioning allele in that there was synthesis of mRNA but no detectable synthesis of pro{alpha}2(I) chains from the allele. The mutation in the other allele caused synthesis of shortened pro{alpha}2(I) chains that lacked most or all of the 18 amino acids encoded by exon 28. Subclones of the pro{alpha}2(I) gene were prepared from the proband's DNA and the DNA sequence was determined for a 582-base-pair (bp) region that extended from the last 30 bp of intervening sequence 26 to the first 26 bp of intervening sequence 29. Data from six independent subclones demonstrated that all had the same sequence as a previously isolated normal clone for the pro{alpha}2(I) gene except that four subclones had a single base mutation at the 3{prime} end of intervening sequence 27. The mutation was a substitution of guanine for adenine that changed the universal consensus sequence for the 3{prime} splicing site of RNA from -AG- to -GG-. S1 nuclease experiments demonstrated that about half the pro{alpha}2(I) mRNA in the proband's fibroblasts was abnormally spliced and that the major species of abnormal pro{alpha}2(I) mRNA was completely spliced from the last codon of exon 27 to the first codon of exon 29. The mutation is apparently unique among RNA splicing mutations of mammalian systems in producing a shortened polypeptide chain that is in-frame in terms of coding sequences, that is used in the subunit assembly of a protein, and that contributes to a lethal phenotype.

  20. Flow cytometric sorting coupled with exon capture sequencing identifies somatic mutations in archival lymphoma tissues.

    Science.gov (United States)

    Jiang, Nenggang; Chen, Christopher; Gong, Qiang; Shields, Kristen; Li, Yuping; Chen, YuanYuan; Song, Joo; McKeithan, Timothy W; Chan, Wing C

    2017-08-07

    The enormous number of archived formalin-fixed paraffin-embedded (FFPE) tissues available are a valuable resource of material for research. However, the use of such tissues poses many challenges, among which is the difficulty of isolating different cell populations within the tissue. In this study, we used tissue from two types of non-Hodgkin lymphoma as a model to demonstrate a method we have established and optimized to separate FFPE samples into distinct tumor and nonmalignant populations. Using FFPE reactive tonsil sections, various approaches for antigen retrieval and labeling, and the effectiveness of flow cytometric sorting were tested. We found that, among the 11 cell surface or intracellular antigen markers investigated, CD3ɛ, CD79A, LAT, PD-1, and PAX5 could be successfully labeled after antigen retrieval in Tris-EDTA buffer (pH 8.0) at 65 °C for 60 min, and 1.8-2.7 μg DNA per million cells could be extracted after sorting with DNA quality similar to that of tissue without staining or sorting. To test whether we could perform next-generation sequencing using a custom capture platform on sorted cells, we used three lymphoma cases with FFPE tissues which had been stored for 1 to 4 years. We demonstrated that the DNA from sorted cells was adequate for exon capture sequencing. By comparing the sequencing results between neoplastic and normal populations, somatic mutations could be clearly identified in the tumor population with variant frequencies as low as 11.7%.The corresponding normal fraction clearly helps in the analysis of somatic mutations and the exclusion of artifacts. This study provides an approach using flow cytometric sorting to separate different cellular populations in paraffin-embedded tissues and to unambiguously distinguish somatic mutations from germline variants or artifacts. This approach is also useful in enriching the tumor component in samples with heterogeneous components and low tumor content.Laboratory Investigation advance

  1. Sequence Comparison of MHC Class Ⅱβ (Exon 2) and Phylogenetic Relationship Between Poultry and Mammalian

    Institute of Scientific and Technical Information of China (English)

    XU Ri-fu; LI Kui; CHEN Guo-hong; QIANG Ba-yang-zong; MO De-lin; LI Chang-chun; FAN Bin; LIU Bang

    2005-01-01

    A fragment spanning over exon 2 and intron 2 of major histocompatibility complex B-LB Ⅱ genes was amplified using PCR,cloned and sequenced in 13 individuals from eight Chinese indigenous chicken breeds and one introduced breed. Another 41 sequences of MHC class Ⅱβ from ten vertebrate species were cited from the NCBI GenBank. Thirteen new B-LB Ⅱ alleles were found in the chicken breeds sampled. Alignment of the exon 2 sequences revealed 91.1-97.8% similarity to each other within the chickens sampled, and the chickens shared 84.1-87.0% homology to Phasianus colchicus, 78.5-81.5% similarity to Coturnixjaponica. The sequences in poultry showed 62.6-68.1% identity to HLA-DRBl, 50-61.5% similarity to DQB (HLA-, SLA- and H2-BB), 53.7-60% to HLA-DPB and 53.3-57.8% similarity to HLA-DOB. The frequency of nonsynonymous substitutions of nucleotide was higher than that of synonymous substitutions, and the frequencies of nonsynonymous and synonymous substitutions in poultry B-LB Ⅱ genes were lower than those observed in mammalian DRB1 and DQB1 genes. The deduced amino acid sequences of MHC class Ⅱβ1 domain exhibited extreme difference in conversed region and variable region patterns among the various species, but the two conserved cysteines forming disulfide-bond were shown consistent in poultry with that in mammalian species; and the carbohydrate attachment site was found more conserved in chicken, Homo sapiens, Bos taurus, Ovis aries and Capra hircus than in Sus scrofa and rodent animals. Compared with exon 2 of DQB1 genes of Homo sapiens, ruminant species and Sus scrofa, the differentia that the deletion of six nucleotides at position195 to 200 of exon 2 of DQB1 genes, and insertion of three nucleotides at position 247 to 249 of the exon 2 existed in rodent species were found, which led to the absence of three AA residues at position 65, 66,and 67 within β1 domain of DQB1 chain, and the insertion of one AA residue at position 85. The difference of the deletion

  2. Two novel exonic point mutations in HEXA identified in a juvenile Tay-Sachs patient: role of alternative splicing and nonsense-mediated mRNA decay.

    Science.gov (United States)

    Levit, A; Nutman, D; Osher, E; Kamhi, E; Navon, R

    2010-06-01

    We have identified three mutations in the beta-hexoseaminidase A (HEXA) gene in a juvenile Tay-Sachs disease (TSD) patient, which exhibited a reduced level of HEXA mRNA. Two mutations are novel, c.814G>A (p.Gly272Arg) and c.1305C>T (p.=), located in exon 8 and in exon 11, respectively. The third mutation, c.1195A>G (p.Asn399Asp) in exon 11, has been previously characterized as a common polymorphism in African-Americans. Hex A activity measured in TSD Glial cells, transfected with HEXA cDNA constructs bearing these mutations, was unaltered from the activity level measured in normal HEXA cDNA. Analysis of RT-PCR products revealed three aberrant transcripts in the patient, one where exon 8 was absent, one where exon 11 was absent and a third lacking both exons 10 and 11. All three novel transcripts contain frameshifts resulting in premature termination codons (PTCs). Transfection of mini-gene constructs carrying the c.814G>A and c.1305C>T mutations proved that the two mutations result in exon skipping. mRNAs that harbor a PTC are detected and degraded by the nonsense-mediated mRNA decay (NMD) pathway to prevent synthesis of abnormal proteins. However, although NMD is functional in the patient's fibroblasts, aberrant transcripts are still present. We suggest that the level of correctly spliced transcripts as well as the efficiency in which NMD degrade the PTC-containing transcripts, apparently plays an important role in the phenotype severity of the unique patient and thus should be considered as a potential target for drug therapy.

  3. A duchenne muscular dystrophy gene hot spot mutation in dystrophin-deficient cavalier king charles spaniels is amenable to exon 51 skipping.

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    Gemma L Walmsley

    Full Text Available BACKGROUND: Duchenne muscular dystrophy (DMD, which afflicts 1 in 3500 boys, is one of the most common genetic disorders of children. This fatal degenerative condition is caused by an absence or deficiency of dystrophin in striated muscle. Most affected patients have inherited or spontaneous deletions in the dystrophin gene that disrupt the reading frame resulting in unstable truncated products. For these patients, restoration of the reading frame via antisense oligonucleotide-mediated exon skipping is a promising therapeutic approach. The major DMD deletion "hot spot" is found between exons 45 and 53, and skipping exon 51 in particular is predicted to ameliorate the dystrophic phenotype in the greatest number of patients. Currently the mdx mouse is the most widely used animal model of DMD, although its mild phenotype limits its suitability in clinical trials. The Golden Retriever muscular dystrophy (GRMD model has a severe phenotype, but due to its large size, is expensive to use. Both these models have mutations in regions of the dystrophin gene distant from the commonly mutated DMD "hot spot". METHODOLOGY/PRINCIPAL FINDINGS: Here we describe the severe phenotype, histopathological findings, and molecular analysis of Cavalier King Charles Spaniels with dystrophin-deficient muscular dystrophy (CKCS-MD. The dogs harbour a missense mutation in the 5' donor splice site of exon 50 that results in deletion of exon 50 in mRNA transcripts and a predicted premature truncation of the translated protein. Antisense oligonucleotide-mediated skipping of exon 51 in cultured myoblasts from an affected dog restored the reading frame and protein expression. CONCLUSIONS/SIGNIFICANCE: Given the small size of the breed, the amiable temperament and the nature of the mutation, we propose that CKCS-MD is a valuable new model for clinical trials of antisense oligonucleotide-induced exon skipping and other therapeutic approaches for DMD.

  4. Pseudohypoparathyroidism type Ib is not caused by mutations in the coding exons of the human parathyroid hormone (PTH)/PTH-related peptide receptor gene

    Energy Technology Data Exchange (ETDEWEB)

    Schipani, E.; Bergwitz, C.; Iida-Klein, A. [Massachusetts General Hospital, Boston, MA (United States)] [and others

    1995-05-01

    Pseudohypoparathyroidism type Ib (PHP-Ib) is thought to be from caused by a PTH/PTH-related peptide (PTHrP) receptor defect. To search for receptor mutations in genomic DNA from 17 PHP-Ib patients, three recently isolated human genomic DNA clones were further characterized by restriction enzyme mapping and nucleotide sequencing across intron/exon borders. Regions including all 14 coding exons and their splice junctions were amplified by polymerase chain reaction, and the products were analyzed by either temperature gradient gel electrophoresis or direct nucleotide sequencing. Silent polymorphisms were identified in exons G (1 of 17), M4 (1 of 17), and M7 (15 of 17). Two base changes were found in introns, 1 at the splice-donor site of the intron between exons E2 and E3 (1 of 17) and the other between exons G and M1 (2 of 17). Total ribonucleic acid from COS-7 cells expressing minigenes with or without the base change between exons E2 and E3 showed no difference by either Northern blot analysis or reverse transcriptase-polymerase chain reaction. Radioligand binding was indistinguishable for both transiently expressed constructs. A missense mutation (E546 to K546) in the receptor`s cytoplamic tail (3 of 17) was also found in 1 of 60 healthy individuals, and PTH/PTHrP receptors with this mutation were functionally indistinguishable from wild-type receptors. PHP-Ib thus appears to be rarely, if ever, caused by mutations in the coding exons of the PTH/PTHrP receptor gene. 58 refs., 4 figs., 4 tabs.

  5. Identification of a novel first exon in the human dystrophin gene and of a new promoter located more than 500 kb upstream of the nearest known promoter

    Energy Technology Data Exchange (ETDEWEB)

    Yanagawa, H.; Nishio, H.; Takeshima, Y. [Kobe Univ. School of Medicine (Japan)] [and others

    1994-09-01

    The dystrophin gene, which is muted in patients with Duchenne and Becker muscular dystrophies, is the largest known human gene. Five alternative promoters have been characterized until now. Here we show that a novel dystrophin isoform with a different first exon can be produced through transcription initiation at a previously-unidentified alternative promoter. The case study presented is that of patient with Duchenne muscular dystrophy who had a deletion extending from 5{prime} end of the dystrophin gene to exon 2, including all promoters previously mapped in the 5{prime} part of the gene. Transcripts from lymphoblastoid cells were found to contain sequences corresponding to exon 3, indicating the presence of new promoter upstream of this exon. The nucleotide sequence of amplified cDNA corresponding to the 5{prime} end of the new transcript indicated that the 5{prime} end of exon 3 was extended by 9 codons, only the last (most 3{prime}) of which codes for methionine. The genomic nucleotide sequence upstream from the new exon, as determined using inverse polymerase chain reaction, revealed the presence of sequences similar to a TATA box, an octamer motif and an MEF-2 element. The identified promoter/exon did not map to intron 2, as might have been expected, but to a position more than 500 kb upstream of the most 5{prime} of the previously-identified promoters, thereby adding 500 kb to the dystrophin gene. The sequence of part of the new promoter region is very similar to that of certain medium reiteration frequency repetitive sequences. These findings may help us understand the molecular evolution of the dystrophin gene.

  6. Transactive response DNA-binding protein 43 (TDP-43) regulates alternative splicing of tau exon 10: Implications for the pathogenesis of tauopathies.

    Science.gov (United States)

    Gu, Jianlan; Chen, Feng; Iqbal, Khalid; Gong, Cheng-Xin; Wang, Xinglong; Liu, Fei

    2017-06-23

    Hyperphosphorylation and aggregation of the neuronal protein tau are responsible for neurodegenerative diseases called tauopathies. Dysregulation of the alternative splicing of tau exon 10 results in alterations of the ratio of two tau isoforms, 3R-tau and 4R-tau, which have been seen in several tauopathies. Transactive response DNA-binding protein of 43 kDa (TDP-43) is involved in the regulation of RNA processing, including splicing. Cytoplasmic aggregation of TDP-43 has been observed in the brains of individuals with chronic traumatic encephalopathy or Alzheimer's disease, diseases in which neurofibrillary tangles of hyperphosphorylated tau are hallmarks. Here, we investigated the role of TDP-43 in tau exon 10 splicing. We found that TDP-43 promoted tau exon 10 inclusion, which increased production of the 4R-tau isoform. Moreover, TDP-43 could bind to intron 9 of tau pre-mRNA. Deletion of the TDP-43 N or C terminus promoted its cytoplasmic aggregation and abolished or diminished TDP-43-promoted tau exon 10 inclusion. Several TDP-43 mutations associated with amyotrophic lateral sclerosis or frontotemporal lobar degeneration with ubiquitin inclusions promoted tau exon 10 inclusion more effectively than wild-type TDP-43 but did not affect TDP-43 cytoplasmic aggregation in cultured cells. The ratio of 3R-tau/4R-tau was decreased in transgenic mouse brains expressing human TDP-43 and increased in the brains expressing the disease-causing mutation TDP-43(M337V), in which cytoplasmic TDP-43 was increased. These findings suggest that TDP-43 promotes tau exon 10 inclusion and 4R-tau expression and that disease-related changes of TDP-43, truncations and mutations, affect its function in tau exon 10 splicing, possibly because of TDP-43 mislocalization to the cytoplasm. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Technology to accelerate pangenomic scanning for unknown point mutations in exonic sequences: cycling temperature capillary electrophoresis (CTCE

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    Bjørheim Jens

    2007-08-01

    Full Text Available Abstract Background Rapid means to discover and enumerate unknown mutations in the exons of human genes on a pangenomic scale are needed to discover the genes carrying inherited risk for common diseases or the genes in which somatic mutations are required for clonal diseases such as atherosclerosis and cancers. The method of constant denaturing capillary electrophoresis (CDCE permitted sensitive detection and enumeration of unknown point mutations but labor-intensive optimization procedures for each exonic sequence made it impractical for application at a pangenomic scale. Results A variant denaturing capillary electrophoresis protocol, cycling temperature capillary electrophoresis (CTCE, has eliminated the need for the laboratory optimization of separation conditions for each target sequence. Here are reported the separation of wild type mutant homoduplexes from wild type/mutant heteroduplexes for 27 randomly chosen target sequences without any laboratory optimization steps. Calculation of the equilibrium melting map of each target sequence attached to a high melting domain (clamp was sufficient to design the analyte sequence and predict the expected degree of resolution. Conclusion CTCE provides practical means for economical pangenomic detection and enumeration of point mutations in large-scale human case/control cohort studies. We estimate that the combined reagent, instrumentation and labor costs for scanning the ~250,000 exons and splice sites of the ~25,000 human protein-coding genes using automated CTCE instruments in 100 case cohorts of 10,000 individuals each are now less than U.S. $500 million, less than U.S. $500 per person.

  8. Mutations in exons of the CYP17-II gene affect sex steroid concentration in male Japanese flounder ( Paralichthys olivaceus)

    Science.gov (United States)

    Ma, Ruiqin; He, Feng; Wen, Haishen; Li, Jifang; Shi, Bao; Shi, Dan; Liu, Miao; Mu, Weijie; Zhang, Yuanqing; Hu, Jian; Han, Weiguo; Zhang, Jianan; Wang, Qingqing; Yuan, Yuren; Liu, Qun

    2012-03-01

    As a specific gene of fish, cytochrome P450c17-II ( CYP17-II) gene plays a key role in the growth, development an reproduction level of fish. In this study, the single-stranded conformational polymorphism (SSCP) technique was used to characterize polymorphisms within the coding region of CYP17-II gene in a population of 75 male Japanese flounder ( Paralichthys olivaceus). Three single nucleotide polymorphisms (SNPs) were identified in CYP17-II gene of Japanese flounder. They were c.G594A (p.G188R), c.G939A and c.G1502A (p.G490D). SNP1 (c.G594A), located in exon 4 of CYP17-II gene, was significantly associated with gonadosomatic index (GSI). Individuals with genotype GG of SNP1 had significantly lower GSI ( P < 0.05) than those with genotype AA or AG. SNP2 (c.G939A) located at the CpG island of CYP17-II gene. The mutation changed the methylation of exon 6. Individuals with genotype AA of SNP2 had significantly lower serum testosterone (T) level and hepatosomatic index (HSI) compared to those with genotype GG. The results suggested that SNP2 could influence the reproductive endocrine of male Japanese flounder. However, the SNP3 (c.G1502A) located in exon 9 did not affect the four measured reproductive traits. This study showed that CYP17-II gene could be a potentially useful candidate gene for the research of genetic breeding and physiological aspects of Japanese flounder.

  9. Dynamics of co-transcriptional pre-mRNA folding influences the induction of dystrophin exon skipping by antisense oligonucleotides.

    Directory of Open Access Journals (Sweden)

    Keng Boon Wee

    Full Text Available Antisense oligonucleotides (AONs mediated exon skipping offers potential therapy for Duchenne muscular dystrophy. However, the identification of effective AON target sites remains unsatisfactory for lack of a precise method to predict their binding accessibility. This study demonstrates the importance of co-transcriptional pre-mRNA folding in determining the accessibility of AON target sites for AON induction of selective exon skipping in DMD. Because transcription and splicing occur in tandem, AONs must bind to their target sites before splicing factors. Furthermore, co-transcriptional pre-mRNA folding forms transient secondary structures, which redistributes accessible binding sites. In our analysis, to approximate transcription elongation, a "window of analysis" that included the entire targeted exon was shifted one nucleotide at a time along the pre-mRNA. Possible co-transcriptional secondary structures were predicted using the sequence in each step of transcriptional analysis. A nucleotide was considered "engaged" if it formed a complementary base pairing in all predicted secondary structures of a particular step. Correlation of frequency and localisation of engaged nucleotides in AON target sites accounted for the performance (efficacy and efficiency of 94% of 176 previously reported AONs. Four novel insights are inferred: (1 the lowest frequencies of engaged nucleotides are associated with the most efficient AONs; (2 engaged nucleotides at 3' or 5' ends of the target site attenuate AON performance more than at other sites; (3 the performance of longer AONs is less attenuated by engaged nucleotides at 3' or 5' ends of the target site compared to shorter AONs; (4 engaged nucleotides at 3' end of a short target site attenuates AON efficiency more than at 5' end.

  10. Mutation analysis of methylmalonyl CoA mutase gene exon 2 in Egyptian families: Identification of 25 novel allelic variants.

    Science.gov (United States)

    Ghoraba, Dina A; Mohammed, Magdy M; Zaki, Osama K

    2015-02-01

    Methylmalonic aciduria (MMA) is an autosomal recessive disorder of methylmalonate and cobalamin (cbl; vitamin B12) metabolism. It is an inborn error of organic acid metabolism which commonly results from a defect in the gene encoding the methylmalonyl-CoA mutase (MCM) apoenzyme. Here we report the results of mutation study of exon 2 of the methylmalonyl CoA mutase (MUT) gene, coding MCM residues from 1 to 128, in ten unrelated Egyptian families affected with methylmalonic aciduria. Patients were presented with a wide-anion gap metabolic acidosis. The diagnosis has established by the measurement of C3 (propionylcarnitine) and C3:C2 (propionylcarnitine/acetylcarnitine) in blood by using liquid chromatography-tandem mass spectrometry (LC/MS-MS) and was confirmed by the detection of an abnormally elevated level of methylmalonic acid in urine by using gas chromatography-mass spectrometry (GC/MS) and isocratic cation exchange high-performance liquid-chromatography (HPLC). Direct sequencing of gDNA of the MUT gene exon 2 has revealed a total of 26 allelic variants: ten of which were intronic, eight were located upstream to the exon 2 coding region, four were novel modifications predicted to affect the splicing region, three were novel mutations within the coding region: c.15G > A (p.K5K), c.165C > A (p.N55K) and c.7del (p.R3EfsX14), as well as the previously reported mutation c.323G > A (p.R108H).

  11. Novel exons in the tbx5 gene locus generate protein isoforms with distinct expression domains and function.

    Science.gov (United States)

    Yamak, Abir; Georges, Romain O; Sheikh-Hassani, Massomeh; Morin, Martin; Komati, Hiba; Nemer, Mona

    2015-03-13

    TBX5 is the gene mutated in Holt-Oram syndrome, an autosomal dominant disorder with complex heart and limb deformities. Its protein product is a member of the T-box family of transcription factors and an evolutionarily conserved dosage-sensitive regulator of heart and limb development. Understanding TBX5 regulation is therefore of paramount importance. Here we uncover the existence of novel exons and provide evidence that TBX5 activity may be extensively regulated through alternative splicing to produce protein isoforms with differing N- and C-terminal domains. These isoforms are also present in human heart, indicative of an evolutionarily conserved regulatory mechanism. The newly identified isoforms have different transcriptional properties and can antagonize TBX5a target gene activation. Droplet Digital PCR as well as immunohistochemistry with isoform-specific antibodies reveal differential as well as overlapping expression domains. In particular, we find that the predominant isoform in skeletal myoblasts is Tbx5c, and we show that it is dramatically up-regulated in differentiating myotubes and is essential for myotube formation. Mechanistically, TBX5c antagonizes TBX5a activation of pro-proliferative signals such as IGF-1, FGF-10, and BMP4. The results provide new insight into Tbx5 regulation and function that will further our understanding of its role in health and disease. The finding of new exons in the Tbx5 locus may also be relevant to mutational screening especially in the 30% of Holt-Oram syndrome patients with no mutations in the known TBX5a exons.

  12. Mutations in Exons of the CYP17- Ⅱ Gene Affect Sex Steroid Concentration in Male Japanese Flounder (Paralichthys olivaceus)

    Institute of Scientific and Technical Information of China (English)

    MA Ruiqin; HU Jian; HAN Weiguo; ZHANG Jianan; WANG Qingqing; YUAN Yuren; LIU Qun; HE Feng; WEN Haishen; LI Jifang; SHI Bao; SHI Dan; LIU Miao; MU Weijie; ZHANG Yuanqing

    2012-01-01

    As a specific gene of fish,cytochrome P450c 17-Ⅱ (CYP17-Ⅱ) gene plays a key role in the growth,development and reproduction level of fish.In this study,the single-stranded conformational polymorphism (SSCP) technique was used to characterize polymorphisms within the coding region of CYP17- Ⅱ gene in a population of 75 male Japanese flounder (Paralichthys olivaceus).Three single nucleotide polymorphisms (SNPs) were identified in CYP17-Ⅱ gene of Japanese flounder.They were c.G594A (p.G188R),c.G939A and c.G1502A (p.G490D).SNP1 (c.G594A),located in exon 4 of CYP17-Ⅱ gene,was significantly associated with gonadosomatic index (GSI).Individuals with genotype GG of SNP1 had significantly lower GSI (P<0.05) than those with genotype AA or AG.SNP2 (c.G939A) located at the CpG island of CYP17-Ⅱ gene.The mutation changed the methylation of exon 6.Individuals with genotype AA of SNP2 had significantly lower serum testosterone (T) level and hepatosomatic index (HSI) compared to those with genotype GG.The results suggested that SNP2 could influence the reproductive endocrine of male Japanese flounder.However,the SNP3 (c.G 1502A) located in exon 9 did not affect the four measured reproductive traits.This study showed that CYP17-Ⅱgene could be a potentially useful candidate gene for the research of genetic breeding and physiological aspects of Japanese flounder.

  13. Mutation analysis of methylmalonyl CoA mutase gene exon 2 in Egyptian families: Identification of 25 novel allelic variants

    Directory of Open Access Journals (Sweden)

    Dina A. Ghoraba

    2015-02-01

    Full Text Available Methylmalonic aciduria (MMA is an autosomal recessive disorder of methylmalonate and cobalamin (cbl; vitamin B12 metabolism. It is an inborn error of organic acid metabolism which commonly results from a defect in the gene encoding the methylmalonyl-CoA mutase (MCM apoenzyme. Here we report the results of mutation study of exon 2 of the methylmalonyl CoA mutase (MUT gene, coding MCM residues from 1 to 128, in ten unrelated Egyptian families affected with methylmalonic aciduria. Patients were presented with a wide-anion gap metabolic acidosis. The diagnosis has established by the measurement of C3 (propionylcarnitine and C3:C2 (propionylcarnitine/acetylcarnitine in blood by using liquid chromatography–tandem mass spectrometry (LC/MS–MS and was confirmed by the detection of an abnormally elevated level of methylmalonic acid in urine by using gas chromatography–mass spectrometry (GC/MS and isocratic cation exchange high-performance liquid-chromatography (HPLC. Direct sequencing of gDNA of the MUT gene exon 2 has revealed a total of 26 allelic variants: ten of which were intronic, eight were located upstream to the exon 2 coding region, four were novel modifications predicted to affect the splicing region, three were novel mutations within the coding region: c.15G>A (p.K5K, c.165C>A (p.N55K and c.7del (p.R3EfsX14, as well as the previously reported mutation c.323G>A (p.R108H.

  14. Correlation of exon 3 β-catenin mutations with glutamine synthetase staining patterns in hepatocellular adenoma and hepatocellular carcinoma.

    Science.gov (United States)

    Hale, Gillian; Liu, Xinxin; Hu, Junjie; Xu, Zhong; Che, Li; Solomon, David; Tsokos, Christos; Shafizadeh, Nafis; Chen, Xin; Gill, Ryan; Kakar, Sanjay

    2016-11-01

    The current clinical practice is based on the assumption of strong correlation between diffuse glutamine synthetase expression and β-catenin activation in hepatocellular adenoma and hepatocellular carcinoma. This high correlation is based on limited data and may represent an oversimplification as glutamine synthetase staining patterns show wide variability in clinical practice. Standardized criteria for interpreting diverse glutamine synthetase patterns, and the association between each pattern and β-catenin mutations is not clearly established. This study examines the correlation between glutamine synthetase staining patterns and β-catenin mutations in 15 typical hepatocellular adenomas, 5 atypical hepatocellular neoplasms and 60 hepatocellular carcinomas. Glutamine synthetase staining was classified into one of the three patterns: (a) diffuse homogeneous: moderate-to-strong cytoplasmic staining in >90% of lesional cells, without a map-like pattern, (b) diffuse heterogeneous: moderate-to-strong staining in 50-90% of lesional cells, without a map-like pattern, and (c) patchy: moderate-to-strong staining in glutamine synthetase staining (homogeneous or heterogeneous), an exon 3 β-catenin mutation was detected in 33% (2/6) of typical hepatocellular adenoma, 75% (3/4) of atypical hepatocellular neoplasm and 17% (8/47) of hepatocellular carcinomas. An exon 3 mutation was also observed in 15% (2/13) of hepatocellular carcinomas with patchy glutamine synthetase staining. The results show a modest correlation between diffuse glutamine synthetase immunostaining and exon 3 β-catenin mutations in hepatocellular adenoma and hepatocellular carcinoma with discrepancy rates >50% in both hepatocellular adenoma and hepatocellular carcinoma. The interpretation of β-catenin activation based on glutamine synthetase staining should be performed with caution, and the undetermined significance of various glutamine synthetase patterns should be highlighted in pathology reports.

  15. Full-exon pyrosequencing screening of BRCA germline mutations in Mexican women with inherited breast and ovarian cancer.

    Directory of Open Access Journals (Sweden)

    Felipe Vaca-Paniagua

    Full Text Available Hereditary breast cancer comprises 10% of all breast cancers. The most prevalent genes causing this pathology are BRCA1 and BRCA2 (breast cancer early onset 1 and 2, which also predispose to other cancers. Despite the outstanding relevance of genetic screening of BRCA deleterious variants in patients with a history of familial cancer, this practice is not common in Latin American public institutions. In this work we assessed mutations in the entire exonic and splice-site regions of BRCA in 39 patients with breast and ovarian cancer and with familial history of breast cancer or with clinical features suggestive for BRCA mutations by massive parallel pyrosequencing. First we evaluated the method with controls and found 41-485 reads per sequence in BRCA pathogenic mutations. Negative controls did not show deleterious variants, confirming the suitability of the approach. In patients diagnosed with cancer we found 4 novel deleterious mutations (c.2805_2808delAGAT and c.3124_3133delAGCAATATTA in BRCA1; c.2639_2640delTG and c.5114_5117delTAAA in BRCA2. The prevalence of BRCA mutations in these patients was 10.2%. Moreover, we discovered 16 variants with unknown clinical significance (11 in exons and 5 in introns; 4 were predicted as possibly pathogenic by in silico analyses, and 3 have not been described previously. This study illustrates how massive pyrosequencing technology can be applied to screen for BRCA mutations in the whole exonic and splice regions in patients with suspected BRCA-related cancers. This is the first effort to analyse the mutational status of BRCA genes on a Mexican-mestizo population by means of pyrosequencing.

  16. Three indel variants in chicken LPIN1 exon 6/flanking region are associated with performance and carcass traits.

    Science.gov (United States)

    Wang, R; Wang, T; Lu, W; Zhang, W; Chen, W; Kang, X; Huang, Y

    2015-01-01

    LPIN1 is a Mg(2+)-dependent phosphatidic acid phosphatase. Variation in chicken LPIN1 exon 6 and its flanking regions were identified and three indel variants in 6 breeds and their associations with performance traits were studied. Seven variants were detected from 6 breeds, which contained a synonymous tri-allelic variant (c.924A/T/C) and three indels. The exon 6 variants detected from chicken breeds were conserved among bird species. The indel variation frequency presented clear differences among breeds. Two coding indels (c.1014-1018del3 and c.1125-1138del12) were multiples of three nucleotides and maintained the open reading frames of LPIN1 proteins. However, they were predicted to result in the clear change of the RNA secondary structure of chicken LPIN1 exon 6 and LPIN1 protein conformation. The association analysis showed that c.871-15-22del6 variation had a significant effect on body weight at hatch (BW0) and 2 weeks (BW2); c. 1014-1018del3 variation had a significant effect on BW4, BW6, caecum length and gizzard weight (GW) traits; c.1125-1138del12 variation had a significant effect on BW12, shank length at 4 weeks (SL4), carcass weight, lactate dehydrogenase traits (LDH), glucose (GLU) and albumin (ALB) traits. The genotype combination for c.1014-1018del3 and c.1125-1138del12 also presented significant effects on SL4, SL8, GW, leg muscle weight, ALB, GLU and LDH. The study demonstrated that chicken LPIN1 has an important effect on body, carcass and organ weight, serum LDH, GLU and ALB level.

  17. Mutation analysis in exons 22 and 24 of SCN4A gene in Iranian patients with non-dystrophic myotonia

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Heidari

    2015-10-01

    Full Text Available Background: Non-dystrophic myotonias are a heterogeneous set of skeletal, muscular channelopathies, which have been associated with point mutations within sodium channel α-subunit (SCN4A gene. Because exons 22 and 24 of SCN4A gene are recognized as hot spots for this disease, the purpose of the study is to identify mutation in exons 22 and 24 of SCN4A gene in Iranian non-dystrophic myotonias patients.Methods: In this study, 28 Iranian patients with non-dystrophic myotonia analyzed for the mutation scanning in exons 22 and 24 of SCN4A gene by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP and sequencing.Results: We found 29073G>C substitution in SCN4A gene in one case and 31506A>G substitution in seven cases. The 29073G>C substitution causes a missense mutation G1306A, located in the conserved cytoplasmic loop connecting repeat III and IV of the SCN4A channel but, 31506A>G substitution do not alter amino acid in SCN4A protein.Conclusion: G1306A residue is located in functionally important protein region. In “hinged-lid model” for Na+ channel inactivation in which glycines1306 act as the hinge of the lid occluding the channel pore. Mutation in this region slowed fast inactivation. Therefore, it might be a pathogenic mutation. The causal relationship of this mutation with the disease is an object for further discussion.

  18. IMGT unique numbering for immunoglobulin and T cell receptor constant domains and Ig superfamily C-like domains

    DEFF Research Database (Denmark)

    Lefranc, Marie-Paule; Pommié, Christelle; Kaas, Quentin

    2005-01-01

    IMGT, the international ImMunoGeneTics information system (http://imgt.cines.fr) provides a common access to expertly annotated data on the genome, proteome, genetics and structure of immunoglobulins (IG), T cell receptors (TR), major histocompatibility complex (MHC), and related proteins...

  19. Comparative sequence analysis in the exon 5 of growth hormone gene in the various livestock species of India.

    Science.gov (United States)

    Singh, Lakshya Veer; Sharma, Anurodh; Kumari, Namita; Kaur, Navneet; Jayakumar, S; Dixit, S P; Gupta, Neelam; Gupta, S C

    2014-01-01

    The aim of the study was to identify genetic polymorphism in growth hormone (GH) gene locus of six different livestock species using PCR-Direct DNA sequencing method. In exon 5 of GH gene, 10 SNPs variants were identified in all livestock species studied, namely Bubalus bubalis, Bos indicus, Bos frontalis, Bos grunniens, Ovis aries, and Capra hircus. Four SNPs were observed in Bubalus bubalis, two SNPs in Bos indicus, one SNP in Ovis aries, and three SNPs in Capra hircus. No changes were observed in Bos grunniens and Bos frontalis when compared with the template sequence and the SNPs observed in the present investigation may be useful in the marker assisted selection.

  20. NMDA-mediated and Self-induced Bdnf Exon IV Transcriptions are Differentially Regulated in Cultured Cortical Neurons

    OpenAIRE

    Zheng, Fei; Wang, Hongbing

    2009-01-01

    Activity-dependent transcriptional up-regulation of bdnf (brain-derived neurotrophic factor) is involved in regulating many aspects of neuronal functions. The NMDA (N-methyl-D-aspartic acid)-mediated and BDNF-mediated exon IV transcription may represent mechanistically different responses, and relevant to activity-dependent changes in neurons. We found that the activities of ERK (extracellular signal-regulated kinase), CaM KII/IV (calmodulin-dependent protein kinase II and IV), PI3K (phosphoi...

  1. 不同品种马ELA-DQA* exon2的多态性分析%Analyzed of ELA-DQA* exon2 Polymorphism of Different Horse Breed

    Institute of Scientific and Technical Information of China (English)

    芒来; 李金莲; 孙玉江; 石有斐; 孟青龙

    2006-01-01

    通过PCR-SSCP技术检测了7个品种300匹马ELA-DQA*exon2的多态性.用12%非变性聚丙烯酰胺凝胶电泳将已变性的PCR扩增产物分离,银染法显色.结果300匹马中共出现27种基因型:10种纯合子和17种杂合子;7个品种马的He和PIC值均表现为高度多态;等位基因序列分析得到10个等位基因间的Kimura双参数遗传距离为0.015~0.147,符合(dN>dS)的正选择检验.因此表明马的ELA-DQA*exon2多态性丰富.

  2. 牦牛和普通牛 DRB1* Intron 1-exon 2序列变异分析%Sequence Variation at BoLA-DRB1 * Intron 1-exon 2 in Yak and Cattle

    Institute of Scientific and Technical Information of China (English)

    田知利; 陈杰; 胡江; 罗玉柱; 刘秀; 李少斌; 郭淑珍; 牟永娟

    2016-01-01

    To accumulate more molecular genetics materials for revealing stress resistance and disease resist-ance breeding by testing the sequence variation at DRB1 gene and analyzing genetic parameters in detecting re-gionin in yak and cattle.Gannan yak,Qinghai yak,Tianzhu white yak,Datong yak and Cattle were used in this stud-y.The polymorphism of intron 1 and exon 2 in BoLA-DRB1 gene were analyzed using PCR-single-strand conforma-tional polymorphism.The results showed that 4 SNPs and 1 insertion /deletion mutation were detected in intron 1 , and 17 SNPs were detected in exon 2,and they were highly polymorphism;Between these two regions,twenty-one haplotypes and the linkage disequilibrium phenomenon were found,and haplptypes A-A 1 ,A-B 1 ,B-A 1 and B-B 1 were most common in yak and cattle.The cluster analysis of DRB1 gene exon 2 showed that yak and other 6 species,cat-tle and goat were the highest on homology and the phylogenetic distance consistent with their genetic relationship. DRB1 gene intron 1 and exon 2 have high of sequence polymorphism,it might be used as genetic marker in yak and cattle.%为揭示牦牛抗逆性及抗病育种积累更多的分子遗传学资料,通过检测 DRB1基因在牦牛和普通牛群体中的变异,分析该基因检测区域遗传参数。以甘南牦牛、青海牦牛、天祝白牦牛、大通牦牛和普通牛为研究对象。应用PCR-SSCP 方法检测 BoLA-DRB1基因第1内含子及第2外显子部分序列多态性。DRB1基因第1内含子区检测到4处 SNPs 及1处插入/缺失突变,第2外显子区检测到17处 SNPs,两区域均表现为高度多态;单倍型连锁分析发现21种 intron 1-exon 2单倍型组型且存在单倍型连锁不平衡现象,A-A 1、A-B 1、B-A 1和 B-B 1单倍型在牦牛和普通牛中频率较高;聚类分析表明,牦牛 DRB1基因第2外显子区碱基序列与普通牛及山羊的同源性最高,系统进化情况与它们亲缘关系远近一致。牦牛和普通牛 Bo

  3. Mutations in the unc-52 gene responsible for body wall muscle defects in adult Caenorhabditis elegans are located in alternatively spliced exons

    Energy Technology Data Exchange (ETDEWEB)

    Rogalski, T.M.; Gilchrist, E.J.; Mullen, G.P. [Univ. of British, Columbia, Vancouver (Canada)] [and others

    1995-01-01

    The unc-52 gene in Caenorhabditis elegans produces several large proteins that function in the basement membrane underlying muscle cells. Mutations in this gene result in defects in myofilament assembly and in the attachment of the myofilament lattice to the muscle cell membrane. The st549 and ut111 alleles of unc-52 produce a lethal (Pat) terminal phenotype whereas the e444, e669, e998, e1012 and e1421 mutations result in viable, paralyzed animals. We have identified the sequence alterations responsible for these mutant phenotypes. The st549 allele has a premature stop codon in exon 7 that should result in the complete elimination of unc-52 gene function, and the ut111 allele has a Tc1 transposon inserted into the second exon of the gene. The five remaining mutations are clustered in a small interval containing three adjacent, alternatively spliced exons (16, 17 and 18). These mutations affect some, but not all of the unc-52-encoded proteins. Thirteen intragenic revertants of the e669, e998, e1012 and e1421 alleles have also been sequenced. The majority of these carry the original mutation plus a G to A transition in the conserved splice acceptor site of the affected exon. This result suggests that reversion of the mutant phenotype in these strains may be the result of exon-skipping. 38 refs., 6 figs., 2 tabs.

  4. Identification of polymorphism in exons 7 and 12 of lactoferrin gene and its association with incidence of clinical mastitis in Murrah buffalo.

    Science.gov (United States)

    Dinesh, Krishanender; Verma, Archana; Das Gupta, Ishwar; Thakur, Yash Pal; Verma, Nishant; Arya, Ashwani

    2015-04-01

    Lactoferrin gene is one of the important candidate genes for mastitis resistance. The gene is located on chromosome BTA 22 and consists of 17 exons spanning over 34.5 kb of genomic DNA. The present study was undertaken with the objectives to identify allelic variants in exons 7 and 12 of lactoferrin gene and to analyze association between its genetic variants and incidence of clinical mastitis in Murrah buffalo. The amplification of exons 7 and 12 of lactoferrin gene yielded amplicons of 232- and 461-bp sizes. PCR-restriction fragment length polymorphism (RFLP) analysis of 232-bp amplicon using BccI restriction enzyme revealed three genotypes (AA, AB, and BB) with frequencies of 0.62, 0.22, and 0.16, respectively. The frequencies of two alleles, A and B, were estimated as 0.73 and 0.27. Hpy188I-RFLP for 461-bp amplicon revealed polymorphism with three genotypes, CC, CD, and DD, with respective frequencies of 0.06, 0.39, and 0.56, whereas frequencies for C and D alleles were 0.25 and 0.75. The chi-square (χ(2)) analysis revealed a significant association between incidence of clinical mastitis and genetic variants of exon 7, and animals of AA genotype of exon 7 were found to be least susceptible to mastitis. The findings indicate potential scope for incorporation of lactoferrin gene in selection and breeding of Murrah buffaloes for improved genetic resistance to mastitis.

  5. Silent exonic mutations in the low-density lipoprotein receptor gene that cause familial hypercholesterolemia by affecting mRNA splicing.

    Science.gov (United States)

    Defesche, J C; Schuurman, E J M; Klaaijsen, L N; Khoo, K L; Wiegman, A; Stalenhoef, A F H

    2008-06-01

    In a large group of patients with the clinical phenotype of familial hypercholesterolemia, such as elevated low-density lipoprotein (LDL) cholesterol and premature atherosclerosis, but without functional mutations in the genes coding for the LDL receptor and apolipoprotein B, we examined the effect of 128 seemingly neutral exonic and intronic DNA variants, discovered by routine sequencing of these genes. Two variants, G186G and R385R, were found to be associated with altered splicing. The nucleotide change leading to G186G resulted in the generation of new 3'-splice donor site in exon 4 and R385R was associated with a new 5'-splice acceptor site in exon 9 of the LDL receptor gene. Splicing of these alternate splice sites leads to an in-frame 75-base pair deletion in a stable mRNA of exon 4 in case of G186G and R385R resulted in a 31-base pair frame-shift deletion in exon 9 and non-sense-mediated mRNA decay.

  6. Complete androgen insensitivity syndrome is frequently due to premature stop codons in exon 1 of the androgen receptor gene: an international collaborative report of 13 new mutations.

    Science.gov (United States)

    Philibert, Pascal; Audran, Françoise; Pienkowski, Catherine; Morange, Isabelle; Kohler, Birgit; Flori, Elisabeth; Heinrich, Claudine; Dacou-Voutetakis, Catherine; Joseph, Marie-Geneviève; Guedj, Anne-Marie; Journel, Hubert; Hecart-Bruna, Annie-Claude; Khotchali, Ines; Ten, Svetlana; Bouchard, Philippe; Paris, Françoise; Sultan, Charles

    2010-07-01

    To confirm the clinical diagnosis of complete androgen insensitivity syndrome (CAIS) by molecular genetic analysis and to determine the prevalence of exon 1 mutations in the androgen receptor (AR) transactivation defects of a large series of CAIS patients. International retrospective study. University Hospital of Montpellier, Department of Hormonology. 105 patients with normal female external genitalia, bilateral intra-abdominal or inguinal testis, normal breast development, absent or sparse pubic hair, normal or high endogenous testosterone production, hypoplastic or absent wolffian structures, and 46,XY karyotype. Sequencing of the AR gene. Prevalence of AR exon 1 mutations. Over a 10-year period (1997 to 2007), we identified 78 AR gene mutations in 105 patients with CAIS; 21 of them were located in exon 1, and 13 of these were new mutations. We report 13 new mutations in the AR gene. All but one were stop codons, and the last was a splicing abnormality. The finding that 27% of the mutations in our cohort were localized in exon 1 versus 15% in previous works justifies the sequencing of this exon in patients with CAIS. Copyright 2010. Published by Elsevier Inc.

  7. A novel point mutation within the EDA gene causes an exon dropping in mature RNA in Holstein Friesian cattle breed affected by X-linked anhidrotic ectodermal dysplasia

    Directory of Open Access Journals (Sweden)

    Pariset Lorraine

    2011-07-01

    Full Text Available Abstract Background X-linked anhidrotic ectodermal dysplasia is a disorder characterized by abnormal development of tissues and organs of ectodermal origin caused by mutations in the EDA gene. The bovine EDA gene encodes the ectodysplasin A, a membrane protein expressed in keratinocytes, hair follicles and sweat glands, which is involved in the interactions between cell and cell and/or cell and matrix. Four mutations causing ectodermal dysplasia in cattle have been described so far. Results We identified a new single nucleotide polymorphism (SNP at the 9th base of exon 8 in the EDA gene in two calves of Holstein Friesian cattle breed affected by ectodermal dysplasia. This SNP is located in the exonic splicing enhancer (ESEs recognized by SRp40 protein. As a consequence, the spliceosome machinery is no longer able to recognize the sequence as exonic and causes exon skipping. The mutation determines the deletion of the entire exon (131 bp in the RNA processing, causing a severe alteration of the protein structure and thus the disease. Conclusion We identified a mutation, never described before, that changes the regulation of alternative splicing in the EDA gene and causes ectodermal dysplasia in cattle. The analysis of the SNP allows the identification of carriers that can transmit the disease to the offspring. This mutation can thus be exploited for a rational and efficient selection of unequivocally healthy cows for breeding.

  8. Identification of Exonic Nucleotide Variants of the Gene Associated with Carcass Traits and Fatty Acid Composition in Korean Cattle

    Directory of Open Access Journals (Sweden)

    Dong-yep Oh

    2014-10-01

    Full Text Available The thyroid hormone responsive protein (THRSP gene is a functional gene that can be used to indicate the fatty acid compositions. This study investigates the relationships of exonic single nucleotide polymorphisms (SNPs in the THRSP gene and fatty acid composition of muscle fat and marbling score in the 612 Korean cattle. The relationships between fatty acid composition and eight SNPs in the THRSP gene (g.78 G>A, g.173 C>T, g.184 C>T, g.190 C>A, g.194 C>T, g.277 C>G, g.283 T>G and g.290 T>G were investigated, and according to the results, two SNPs (g.78 G>A and g.184 C>T in exon 1 were associated with fatty acid composition. The GG and CC genotypes of g.78 G>A and g.184 C>T had higher unsaturated fatty acid (UFA and monounsaturated fatty acid (MUFA content (pA and g.184 C>T had significantly relationships with UFAs and MUFAs. Two SNPs in the THRSP gene affected fatty acid composition, suggesting that GG and CC genotypes and the ht1*ht1 group (Val/Ala haplotype can be markers to genetically improve the quality and flavor of beef.

  9. Association of G>A transition in exon-1 of alpha crystallin gene in age-related cataracts

    Directory of Open Access Journals (Sweden)

    S G Bhagyalaxmi

    2010-01-01

    Full Text Available Aim : To identify the presence of a known or novel mutation/SNP in Exon-1 (ex-1 of alpha crystallin (CRYAA gene in different types of age-related cataract (ARC patients. Materials and Methods : Single strand Conformation Polymorphism (SSCP analysis was carried for the detection of single nucleotide polymorphism (SNP in ex-1 of alpha crystallin (CRYAA gene which was confirmed by sequencing. Results : The SSCP analysis of ex-1 of CRYAA gene revealed mobility shift in patients and controls, which was due to G>A transition at 6 th position in exon-1 of CRYAA gene. All the three genotypes, GG, AA and GA, were detected in patients and controls indicating that G>A substitution is polymorphic. The analysis showed significant risk for heterozygotes (GA as compared to pooled frequencies of homozygotes (GG+AA, which was 1.81 times for all the types of cataracts in general and 2.5 times for Nuclear Cataract and twice for Cortical Cataract. Conclusion : The GA heterozygotes were at higher risk for developing NC and CC types of cataracts, where as the GG homozygotes for MT and AA homozygotes for PSC types were at risk. To our knowledge, an association of G>A transition found in ex-1 of CRYAA gene with ARC, with differential risk of genotypes for individual type of cataracts has not been reported previously.

  10. Cloning and expression of acetylcholinesterase from Electrophorus. Splicing pattern of the 3' exons in vivo and in transfected mammalian cells.

    Science.gov (United States)

    Simon, S; Massoulié, J

    1997-12-26

    We cloned and expressed a cDNA encoding acetylcholinesterase (AChE) of type T from Electrophorus electricus organs. When expressed in COS, HEK, and Chinese hamster ovary cells, the AChET subunits generated dimers and tetramers. The cells produced more activity at 27 than at 37 degrees C. The kinetic parameters of a recombinant enzyme, produced in the yeast Pichia pastoris, were close to those of the natural AChE. Analysis of genomic clones showed that the coding sequence is interrupted by an intron that does not exist in Torpedo and differs in its location from that observed in the mouse. This intron is preceded by a sequence encoding a non-conserved 29-amino acid peptide, which does not exist in Torpedo or mammalian AChEs. According to a three-dimensional model, this non-conserved peptide is located at the surface of the protein, opposite from the entry of the catalytic gorge; its deletion did not modify the catalytic parameters. Sequence analyses and expression of various constructs showed that the gene does not contain any H exon. We also found that splicing of transcripts in mammalian cells reveals cryptic donor sites in exons and acceptor sites in introns, which do not appear to be used in vivo.

  11. Single Nucleotide Polymorphisms (SNPs in Exon 6 of Lecithin Cholesterol Acyltransferase (LCAT Gene in Indonesian Local Sheep

    Directory of Open Access Journals (Sweden)

    Hidayati

    2014-08-01

    Full Text Available Lecithin cholesterol acyltransferase (LCAT is a soluble enzyme that converts cholesterol and lecithin to cholesteryl esters and lysolecithins on the surface of high density lipoprotein and plays an important role in lipoprotein metabolism. The research was aimed to explore single nucleotide polymorphisms of LCAT gene in Indonesian local sheep. A total of 118 genomic DNA of Indonesian local sheep were used in this research, consisted of Sumatera Thin Tail (43 heads, Garut (19 heads, Javanese Thin Tail (17 heads, Javanese Fat Tail (6 heads, Rote Island (7 heads, Kissar (7 heads, Sumbawa (10 heads, and Lembah Palu (9 heads. Polymerase chain reaction was used to amplify genomic DNA for exon 6 (250 bp and direct sequencing method was used to identify polymorphism sequences. The sequences were analyzed with BioEdit and MEGA 5.2 software. The BLAST sequence was obtained from Gene Bank GQ 150556.1. The results showed three novel SNPs, i.e. c.742C>T, c.770 T>A and c.882C>T. Substitution of cytosine to thymine c.742 is a synonymous mutation; thymine to adenine c.770 and cytosine to thymine c.882 are non-synonymous mutations. Polymorphisms of LCAT gene exon 6 was found in Sumatera Thin Tail, Javanese Thin Tail, Javanese Fat Tail, Garut, Lembah Palu, and Rote Island.

  12. Methyl-Cytosine-Driven Structural Changes Enhance Adduction Kinetics of an Exon 7 fragment of the p53 Gene

    Science.gov (United States)

    Malla, Spundana; Kadimisetty, Karteek; Fu, You-Jun; Choudhary, Dharamainder; Schenkman, John B.; Rusling, James F.

    2017-01-01

    Methylation of cytosine (C) at C-phosphate-guanine (CpG) sites enhances reactivity of DNA towards electrophiles. Mutations at CpG sites on the p53 tumor suppressor gene that can result from these adductions are in turn correlated with specific cancers. Here we describe the first restriction-enzyme-assisted LC-MS/MS sequencing study of the influence of methyl cytosines (MeC) on kinetics of p53 gene adduction by model metabolite benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), using methodology applicable to correlate gene damage sites for drug and pollutant metabolites with mutation sites. This method allows direct kinetic measurements by LC-MS/MS sequencing for oligonucleotides longer than 20 base pairs (bp). We used MeC and non-MeC (C) versions of a 32 bp exon 7 fragment of the p53 gene. Methylation of 19 cytosines increased the rate constant 3-fold for adduction on G at the major reactive CpG in codon 248 vs. the non-MeC fragment. Rate constants for non-CpG codons 244 and 243 were not influenced significantly by MeC. Conformational and hydrophobicity changes in the MeC-p53 exon 7 fragment revealed by CD spectra and molecular modeling increase the BPDE binding constant to G in codon 248 consistent with a pathway in which preceding reactant binding greatly facilitates the rate of covalent SN2 coupling.

  13. Methyl-Cytosine-Driven Structural Changes Enhance Adduction Kinetics of an Exon 7 fragment of the p53 Gene

    Science.gov (United States)

    Malla, Spundana; Kadimisetty, Karteek; Fu, You-Jun; Choudhary, Dharamainder; Schenkman, John B.; Rusling, James F.

    2017-01-01

    Methylation of cytosine (C) at C-phosphate-guanine (CpG) sites enhances reactivity of DNA towards electrophiles. Mutations at CpG sites on the p53 tumor suppressor gene that can result from these adductions are in turn correlated with specific cancers. Here we describe the first restriction-enzyme-assisted LC-MS/MS sequencing study of the influence of methyl cytosines (MeC) on kinetics of p53 gene adduction by model metabolite benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), using methodology applicable to correlate gene damage sites for drug and pollutant metabolites with mutation sites. This method allows direct kinetic measurements by LC-MS/MS sequencing for oligonucleotides longer than 20 base pairs (bp). We used MeC and non-MeC (C) versions of a 32 bp exon 7 fragment of the p53 gene. Methylation of 19 cytosines increased the rate constant 3-fold for adduction on G at the major reactive CpG in codon 248 vs. the non-MeC fragment. Rate constants for non-CpG codons 244 and 243 were not influenced significantly by MeC. Conformational and hydrophobicity changes in the MeC-p53 exon 7 fragment revealed by CD spectra and molecular modeling increase the BPDE binding constant to G in codon 248 consistent with a pathway in which preceding reactant binding greatly facilitates the rate of covalent SN2 coupling. PMID:28102315

  14. Cationic polyelectrolyte-mediated delivery of antisense morpholino oligonucleotides for exon-skipping in vitro and in mdx mice.

    Science.gov (United States)

    Wang, Mingxing; Wu, Bo; Tucker, Jason D; Lu, Peijuan; Lu, Qilong

    2015-01-01

    In this study, we investigated a series of cationic polyelectrolytes (PEs) with different size and composition for their potential to improve delivery of an antisense phosphorodiamidate morpholino oligomer (PMO) both in vitro and in vivo. The results showed that the poly(diallyldimethylammonium chloride) (PDDAC) polymer series, especially PE-3 and PE-4, improves the delivery efficiency of PMO, comparable with Endoporter-mediated PMO delivery in vitro. The enhanced PMO delivery and targeting to dystrophin exon 23 was further observed in mdx mice, up to fourfold with the PE-4, compared with PMO alone. The cytotoxicity of the PEs was lower than that of Endoporter and polyethylenimine 25,000 Da in vitro, and was not clearly detected in muscle in vivo under the tested concentrations. Together, these results demonstrate that optimization of PE molecular size, composition, and distribution of cationic charge are key factors to achieve enhanced PMO exon-skipping efficiency. The increased efficiency and lower toxicity show this PDDAC series to be capable gene/antisense oligonucleotide delivery-enhancing agents for treating muscular dystrophy and other diseases.

  15. Molecular evolution of the exon 2 of CHS genes and the possibility of its application to plant phylogenetic analysis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The exon 2 of chalcone synthase (CHS) gene is relatively conserved during evolution.In this study,three exon 2 fragments from two species in gymnosperm (Cycas panzhihuaensis,Ginkgo biloba) and seven from four species in angiosperm (Magnolia denudata,Salix babylonica,Nymphaea tetragona,Camellia japonica) have been amplified by PCR from genomic DNA and sequenced.Together with other 73 sequences of CHS collected from EMBL database and literature,these sequences,which embrace 19 families of gymnosperm and angiosperm,have been analyzed for their phylogenetic relations by parsimony method.The result indicated that sequences from the same systematic family usually grouped together except those from Theaceae,Magnoliaceae and Nymphaeaceae.The relative rate test revealed the rate heterogeneity of CHS genes among the families.For the nucleotide substitution the sequences from Asteraceae and Solanaceae evolve faster than those from the other families analyzed while the sequences from Poaceae,Asteraceae and Solanaceae evolve faster for the nonsynonymous substitution.These results suggest that the duplication and extinction events of CHS genes are different among systematic families,therefore it seems impractical to look for orthologous sequences from CHS genes to study plant phylogeny at the family level and/or above.However,it is possible to do so below the family level.

  16. Becker Muscular Dystrophy (BMD) caused by duplication of exons 3-6 of the dystrophin gene presenting as dilated cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, A.C.; Allingham-Hawkins, D.J.; Becker, L. [Univ. of Toronto, Ontario (Canada)] [and others

    1994-09-01

    X-linked dilated cardiomyopathy (XLCM) is a progressive myocardial disease presenting with congestive heart failure in teenage males without clinical signs of skeletal myopathy. Tight linkage of XLCM to the DMD locus has been demonstrated; it has been suggested that, at least in some families, XLCM is a {open_quotes}dystrophinopathy.{close_quotes} We report a 14-year-old boy who presented with acute heart failure due to dilated cardiomyopathy. He had no history of muscle weakness, but physical examination revealed pseudohypertrophy of the calf muscles. He subsequently received a heart transplantation. Family history was negative. Serum CK level at the time of diagnosis was 10,416. Myocardial biopsy showed no evidence of carditis. Dystrophin staining of cardiac and skeletal muscle with anti-sera to COOH and NH{sub 2}termini showed a patchy distribution of positivity suggestive of Becker muscular dystrophy. Analysis of 18 of the 79 dystrophin exons detected a duplication that included exons 3-6. The proband`s mother has an elevated serum CK and was confirmed to be a carrier of the same duplication. A mutation in the muscle promotor region of the dystrophin gene has been implicated in the etiology of SLCM. However, Towbin et al. (1991) argued that other 5{prime} mutations in the dystrophin gene could cause selective cardiomyopathy. The findings in our patient support the latter hypothesis. This suggests that there are multiple regions in the dystrophin gene which, when disrupted, can cause isolated dilated cardiomyopathy.

  17. Association of Single Nucleotide Polymorphisms in Exon 3 of Porcine LMCD1 Gene with Meat Quality and Carcass Traits

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; DENG Chang-yan; XIONG Yuan-zhu; ZUO Bo; LI Feng-e; LEI Ming-gang; ZHENG Rong; LI Jia-lian; JIANG Si-wen

    2008-01-01

    LIM domain proteins are found to be important regulators in cell growth,cell fate determination,cell differentiation,and remodelling of the cell cytoskeleton by their interaction with some structural proteins,kinases,transcriptional regulators,etc.The presence of LIM domains in LMCDI gene implies it may be involved in skeletal muscle protein-protein interactions.This study was to investigate polymorphisms of LIM and cysteine-rich domain 1(LMCD1)gene and its effect on meat quality and carcass traits in pig.The polymorphism(G294A)in exon 3 region of porcine LMCD1 gene,which is synonymous mutation,was genotyped in the population of 178 F2 pigs of a Large White×Meishan resource family.Statistical results indicated the distribution of allele G(with a A→G mutation)and A(without mutation).Analysis of variante showed that the polymorphism of LMCD1 gene was associated with variation in several carcass traits of interest for pig breeding.Some carcass traits and meat quality traits are close to significance by association.An analysis of more animals is necessary to analyze the polymorphisms in exon 3 of porcine LMCD1 gene if it was selected as a marker for the pig carcass traits.

  18. Polymorphisms in exons 1B and 1C of the type I interleukin-1 receptor gene in patients with endometriosis.

    Science.gov (United States)

    D'Amora, Paulo; Sato, Hélio; Girão, Manoel J B C; Silva, Ismael D C G; Schor, Eduardo

    2006-09-01

    To study possible correlation between the prevalence of polymorphisms in the type I interleukin-1 receptor gene and pelvic endometriosis. Genotypes of 223 women were analyzed: 109 women with surgically and histologically confirmed endometriosis and 114 healthy women. Distributions of two single-base polymorphisms of the human interleukin-1 receptor type I (IL-1RI) gene were evaluated: PstI, due to a C-->T transition in exon 1B and BsrBI a C-->A transition at position 52 in exon 1C. Polymorphisms were detected by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism analysis (RFLP) resolved on 3% agarose gels stained with ethidium bromide. Genotypes for PstI polymorphisms did not differ significantly among control and endometriosis (P = 0.058). However, in relation to BsrBI polymorphism, protective risk was observed for the development of endometriosis [OR 0.39-IC 95% (0.2-0.9)]. BsrBI heterozygote genotype (C/A) showed protective effect against endometriosis development.

  19. Association between the Growth Hormone Receptor Exon 3 Polymorphism and Metabolic Factors in Korean Patients with Acromegaly

    Directory of Open Access Journals (Sweden)

    Hye Yoon Park

    2015-09-01

    Full Text Available BackgroundThis study investigated the association between the frequency of growth hormone receptor (GHR exon 3 polymorphism (exon 3 deletion; d3-GHR and metabolic factors in patients with acromegaly in Korea.MethodsDNA was extracted from the peripheral blood of 30 unrelated patients with acromegaly. GHR genotypes were evaluated by polymerase chain reaction and correlated with demographic data and laboratory parameters.ResultsNo patient had the d3/d3 genotype, while four (13.3% had the d3/fl genotype, and 26 (86.7% had the fl/fl genotype. Body mass index (BMI in patients with the d3/fl genotype was significantly higher than in those with the fl/fl genotype (P=0.001. Age, gender, blood pressure, insulin-like growth factor-1, growth hormone, fasting plasma glucose, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol levels showed no significant differences between the two genotypes.ConclusionThe d3-GHR polymorphism may be associated with high BMI but not with other demographic characteristics or laboratory parameters.

  20. Detection of mutations within exons 4 to 8 of the p53 tumor suppressor gene in canine mammary glands

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    D.M.B. Souza

    2012-04-01

    Full Text Available Fifteen female canines with mammary tumors and 6 normal females were used to study mutations in exons 4 to 8 of the p53 gene. DNA samples from the tumors, respective adjacent normal mammary tissue and mammary glands from healthy animals were sequenced and analyzed for the presence of mutations. Mutations were found in 71.8% of the samples and the most frequent were missense mutations. The most attacked exons in the mammary tumor were 5, 7 and 8, with 23.4, 31.6 and 23.4% mutations, respectively. Canine mammary tumors are related to mutations in gene p53 and mutations mostly occur in the region of the protein that is linked to the DNA in the cell nucleus, which can change the functionality of the cell and propitiate tumor growth. Despite being macroscopically normal, the mammary tissue adjacent to the tumors has mutations that can lead to recurrence if not removed together with the tumor.

  1. An Enhancer Near ISL1 and an Ultraconserved Exon of PCBP2 areDerived from a Retroposon

    Energy Technology Data Exchange (ETDEWEB)

    Bejerano, Gill; Lowe, Craig; Ahituv, Nadav; King, Bryan; Siepel,Adam; Salama, Sofie; Rubin, Edward M.; Kent, W. James; Haussler, David

    2005-11-27

    Hundreds of highly conserved distal cis-regulatory elementshave been characterized to date in vertebrate genomes1. Many thousandsmore are predicted based on comparative genomics2,3. Yet, in starkcontrast to the genes they regulate, virtually none of these regions canbe traced using sequence similarity in invertebrates, leaving theirevolutionary origin obscure. Here we show that a class of conserved,primarily non-coding regions in tetrapods originated from a novel shortinterspersed repetitive element (SINE) retroposon family that was activein Sarcopterygii (lobe-finned fishes and terrestrial vertebrates) in theSilurian at least 410 Mya4, and, remarkably, appears to be recentlyactive in the "living fossil" Indonesian coelacanth, Latimeriamenadoensis. We show that one copy is a distal enhancer, located 500kbfrom the neuro-developmental gene ISL1. Several others represent new,possibly regulatory, alternatively spliced exons in the middle ofpre-existing Sarcopterygian genes. One of these is the>200bpultraconserved region5, 100 percent identical in mammals, and 80 percentidentical to the coelacanth SINE, that contains a 31aa alternativelyspliced exon of the mRNA processing gene PCBP26. These add to a growinglist of examples7 in which relics of transposable elements have acquireda function that serves their host, a process termed "exaptation"8, andprovide an origin for at least some of the highly-conservedvertebrate-specific genomic sequences recently discovered usingcomparative genomics.

  2. Identification of coding exon 3 duplication in the BMPR1A gene in a patient with juvenile polyposis syndrome.

    Science.gov (United States)

    Yamaguchi, Junya; Nagayama, Satoshi; Chino, Akiko; Sakata, Ai; Yamamoto, Noriko; Sato, Yuri; Ashihara, Yuumi; Kita, Mizuho; Nomura, Sachio; Ishikawa, Yuichi; Igarashi, Masahiro; Ueno, Masashi; Arai, Masami

    2014-10-01

    Juvenile polyposis syndrome is an autosomal dominant inherited disorder characterized by multiple juvenile polyps arising in the gastrointestinal tract and an increased risk of gastrointestinal cancers, specifically colon cancer. BMPR1A and SMAD4 germline mutations have been found in patients with juvenile polyposis syndrome. We identified a BMPR1A mutation, which involves a duplication of coding exon 3 (c.230+452_333+441dup1995), on multiple ligation dependent probe amplification in a patient with juvenile polyposis syndrome. The mutation causes a frameshift, producing a truncated protein (p.D112NfsX2). Therefore, the mutation is believed to be pathogenic. We also identified a duplication breakpoint in which Alu sequences are located. These results suggest that the duplication event resulted from recombination between Alu sequences. To our knowledge, partial duplication in the BMPR1A gene has not been reported previously. This is the first case report to document coding exon 3 duplication in the BMPR1A gene in a patient with juvenile polyposis syndrome.

  3. Dopamine D4 receptor exon III polymorphism, adverse life events and personality traits in a nonclinical German adult sample.

    Science.gov (United States)

    Reiner, Iris; Spangler, Gottfried

    2011-01-01

    Personality and temperament embrace a wide area of both psychological and behavioral processes which are also based on disposition. A functional polymorphism in exon III of the dopamine D4 receptor gene (DRD4) has been a highly suspect genetic marker for personality in spite of ambiguous results. The present study aimed to further elucidate the relationship between DRD4, negative life events and personality in a representative nonclinical sample. Hundred sixty-seven Germans completed the NEO Five-Factor Inventory, the Tridimensional Personality Questionnaire and the California Adult Q-Sort. A factor analysis revealed 3 factors: emotional stability, social orientation and impulsivity. DNA from buccal cells was genotyped for the DRD4 variable-number tandem-repeat exon III polymorphism with respect to presence versus absence of the DRD4 7-repeat allele. Adverse life events were assessed by means of the Adverse Life Events Scale. Men carrying the DRD4 7-repeat allele were more impulsive than those without. Male 7-repeat carriers were more emotionally instable than others, but only when they experienced a large amount of negative life events. No genotype-personality relationships were found for women. The results indicate gender-specific influences of the DRD4 gene on human behavior and invite researchers to further investigate gene-environment correlations on personality traits.

  4. Shank3-mutant mice lacking exon 9 show altered excitation/inhibition balance, enhanced rearing, and spatial memory deficit

    Directory of Open Access Journals (Sweden)

    Jiseok eLee

    2015-03-01

    Full Text Available Shank3 is a postsynaptic scaffolding protein implicated in synapse development and autism spectrum disorders. The Shank3 gene is known to produce diverse splice variants whose functions have not been fully explored. In the present study, we generated mice lacking Shank3 exon 9 (Shank3∆9 mice, and thus missing 5 out of 10 known Shank3 splice variants containing the N-terminal ankyrin repeat region, including the longest splice variant, Shank3a. Our X-gal staining results revealed that Shank3 proteins encoded by exon 9-containing splice variants are abundant in upper cortical layers, striatum, hippocampus, and thalamus, but not in the olfactory bulb or cerebellum, despite the significant Shank3 mRNA levels in these regions. The hippocampal CA1 region of Shank3∆9 mice exhibited reduced excitatory transmission at Schaffer collateral synapses and increased frequency of spontaneous inhibitory synaptic events in pyramidal neurons. In contrast, prelimbic layer 2/3 pyramidal neurons in the medial prefrontal cortex displayed decreased frequency of spontaneous inhibitory synaptic events, indicating alterations in the ratio of excitation/inhibition (E/I ratio in the Shank3∆9 brain. These mice displayed a mild increase in rearing in a novel environment and mildly impaired spatial memory, but showed normal social interaction and repetitive behavior. These results suggest that ankyrin repeat-containing Shank3 splice variants are important for E/I balance, rearing behavior, and spatial memory.

  5. Use of intron-exonic marker in assessment of genetic diversity of two subspecies of Thymus daenensis

    Directory of Open Access Journals (Sweden)

    Ahmad Ismaili

    2013-11-01

    Full Text Available Study of genetic diversity in medicinal plant is very important for improvement and evolutionary variations. In this study, assessment of genetic diversity in two subspecies of Thymus daenensis was evaluated, using intron-exonic markers. Thirty primers produced 633 polymorphic bands (98% polymorphism. The highest polymorphic information content (PIC included ISJ5 and ISJ9 primers and the lowest PIC also included IT15-32 primer. The highest marker index (MI produced by IT10-6 primer. Results of Analysis of Molecular Variance (AMOVA showed that intra-sub specific variation was more than inter-sub specific variation. Dendrogram obtained from Cluster analysis, using NTSYS-pc software and UPGMA method based on Dice's similarity matrix, divided accessions into 4 groups. The maximum range of genetic similarity was observed between two accessions of sub-species daenensis. Two accessions of Fars and Semnan formed a separate group. Results showed that clustering based on molecular data and principal coordinate analysis had a medium alignment. Grouping based on cluster analysis also could separate two subspecies of Thymus daenensis. Results obtained from this study showed that intron-exonic markers had an effective potential in assessment of genetic relationships between the two sub-species of daenensis.

  6. Splicing defects caused by exonic mutations in PKD1 as a new mechanism of pathogenesis in autosomal dominant polycystic kidney disease.

    Science.gov (United States)

    Claverie-Martin, Felix; Gonzalez-Paredes, Francisco J; Ramos-Trujillo, Elena

    2015-01-01

    The correct splicing of precursor-mRNA depends on the actual splice sites plus exonic and intronic regulatory elements recognized by the splicing machinery. Surprisingly, an increasing number of examples reveal that exonic mutations disrupt the binding of splicing factors to these sequences or generate new splice sites or regulatory elements, causing disease. This contradicts the general assumption that missense mutations disrupt protein function and that synonymous mutations are merely polymorphisms. Autosomal dominant polycystic kidney disease (ADPKD) is a common inherited disorder caused mainly by mutations in the PKD1 gene. Recently, we analyzed a substantial number of PKD1 missense or synonymous mutations to further characterize their consequences on pre-mRNA splicing. Our results showed that one missense and 2 synonymous mutations induce significant defects in pre-mRNA splicing. Thus, it appears that aberrant splicing as a result of exonic mutations is a previously unrecognized cause of ADPKD.

  7. High expression level of Tra2-β1 is responsible for increased SMN2 exon 7 inclusion in the testis of SMA mice.

    Science.gov (United States)

    Chen, Yu-Chia; Chang, Jan-Gowth; Jong, Yuh-Jyh; Liu, Ting-Yuan; Yuo, Chung-Yee

    2015-01-01

    Spinal muscular atrophy (SMA) is an inherited neuromuscular disease caused by deletion or mutation of SMN1 gene. All SMA patients carry a nearly identical SMN2 gene, which produces low level of SMN protein due to mRNA exon 7 exclusion. Previously, we found that the testis of SMA mice (smn-/- SMN2) expresses high level of SMN2 full-length mRNA, indicating a testis-specific mechanism for SMN2 exon 7 inclusion. To elucidate the underlying mechanism, we established primary cultures of testis cells from SMA mice and analyzed them for SMN2 exon 7 splicing. We found that primary testis cells after a 2-hour culture still expressed high level of SMN2 full-length mRNA, but the level decreased after longer cultures. We then compared the protein levels of relevant splicing factors, and found that the level of Tra2-β1 also decreased during testis cell culture, correlated with SMN2 full-length mRNA downregulation. In addition, the testis of SMA mice expressed the highest level of Tra2-β1 among the many tissues examined. Furthermore, overexpression of Tra2-β1, but not ASF/SF2, increased SMN2 minigene exon 7 inclusion in primary testis cells and spinal cord neurons, whereas knockdown of Tra2-β1 decreased SMN2 exon 7 inclusion in primary testis cells of SMA mice. Therefore, our results indicate that high expression level of Tra2-β1 is responsible for increased SMN2 exon 7 inclusion in the testis of SMA mice. This study also suggests that the expression level of Tra2-β1 may be a modifying factor of SMA disease and a potential target for SMA treatment.

  8. Common exon 3 polymorphism of the GH receptor (GHR) gene and effect of GH therapy on growth in Korean children with idiopathic short stature (ISS).

    Science.gov (United States)

    Ko, Jung Min; Park, Jung Young; Yoo, Han-Wook

    2009-01-01

    A human GH receptor (GHR) gene exon 3 polymorphism (d3-GHR) has been reported to be associated with responsiveness to GH therapy. We assessed the frequencies of this polymorphism in Korean control and idiopathic short stature (ISS) populations, and analysed short-term growth response to GH therapy according to GHR-exon 3 genotypes in Korean children with ISS. This was a retrospective study in 158 ISS children. Auxological and endocrine parameters were measured, and the GHR-exon 3 genotype was analysed. Allelic frequencies of GHR-exon 3 genotype were compared between the ISS group and a control group. GH had been administered for 62 patients, 52 of whom remained prepubertal after the first follow-up year. Changes in height velocity (HV) and IGF-1 and IGFBP-3 concentrations following GH therapy were compared in patients with these genotypes. There was no difference in GHR-exon 3 genotype frequency between ISS and control groups of Koreans. However, the fl/fl genotype was more frequent in Koreans than in Caucasians. ISS children with d3-GHR showed a significantly higher increment in HV (P = 0.002) and a marginally significant increment in IGF-1 concentration (P = 0.064) at the first year of GH therapy. fl-GHR was more frequently detected in a Korean population than in Caucasians. The growth promotion efficacy of GH therapy differed significantly between ISS patients with and without the d3-GHR allele. These findings indicate that the GHR-exon 3 polymorphism can affect the growth promoting efficacy of short-term GH therapy in Korean children with ISS.

  9. Potent inhibition of angiotensin AT1 receptor signaling by RGS8: importance of the C-terminal third exon part of its RGS domain.

    Science.gov (United States)

    Song, Dan; Nishiyama, Mariko; Kimura, Sadao

    2016-10-01

    R4/B subfamily RGS (regulator of G protein signaling) proteins play roles in regulation of many GPCR-mediated responses. Multiple RGS proteins are usually expressed in a cell, and it is difficult to point out which RGS protein species are functionally important in the cell. To evaluate intrinsic potency of these RGS proteins, we compared inhibitory effects of RGS1, RGS2, RGS3, RGS4, RGS5, RGS8 and RGS16 on AT1 receptor signaling. Intracellular Ca(2+) responses to angiotensin II were markedly attenuated by transiently expressed RGS2, RGS3 and RGS8, compared to weak inhibition by RGS1, RGS4, RGS5 and RGS16. N-terminally deleted RGS2 (RGS2 domain) lost this potent inhibitory effect, whereas RGS domains of RGS3 and RGS8 showed strong inhibition similar to those of the full-length proteins. To investigate key determinants that specify the differences in potency, we constructed chimeric domains by replacing one or two of three exon parts of RGS8 domain with the corresponding part of RGS5. The chimeric RGS8 domains containing the first or the second exon part of RGS5 showed strong inhibitory effects similar to that of wild type RGS8, but the chimeric domain with the third exon part of RGS5 lost its activity. On the contrary, replacement of the third exon part of RGS5 with the corresponding residues of RGS8 increased the inhibitory effect. The role of the third exon part of RGS8 domain was further confirmed with the chimeric RGS8/RGS4 domains. These results indicate the potent inhibitory activity of RGS8 among R4/B subfamily proteins and importance of the third exon.

  10. Genetic and functional analysis of human P2X5 reveals a distinct pattern of exon 10 polymorphism with predominant expression of the nonfunctional receptor isoform.

    Science.gov (United States)

    Kotnis, Smita; Bingham, Brendan; Vasilyev, Dmitry V; Miller, Scott W; Bai, Yuchen; Yeola, Sarita; Chanda, Pranab K; Bowlby, Mark R; Kaftan, Edward J; Samad, Tarek A; Whiteside, Garth T

    2010-06-01

    P2X5 is a member of the P2X family of ATP-gated nonselective cation channels, which exist as trimeric assemblies. P2X5 is believed to trimerize with another member of this family, P2X1. We investigated the single-nucleotide polymorphism (SNP) at the 3' splice site of exon 10 of the human P2X5 gene. As reported previously, presence of a T at the SNP location results in inclusion of exon 10 in the mature transcript, whereas exon 10 is excluded when a G is present at this location. Our genotyping of human DNA samples reveals predominance of the G-bearing allele, which was exclusively present in DNA samples from white American, Middle Eastern, and Chinese donors. Samples from African American donors were polymorphic, with the G allele more frequent. Reverse transcription-polymerase chain reaction analysis of lymphocytes demonstrated a 100% positive correlation between genotype and P2X5 transcript. Immunostaining of P2X1/P2X5 stably coexpressing cell lines showed full-length P2X5 to be expressed at the cell surface and the exon 10-deleted isoform to be cytoplasmic. Fluorometric imaging-based pharmacological characterization indicated a ligand-dependent increase in intracellular calcium in 1321N1 astrocytoma cells transiently expressing full-length P2X5 but not the exon 10-deleted isoform. Likewise, electrophysiological analysis showed robust ATP-evoked currents when full-length but not the exon 10-deleted isoform of P2X5 was expressed. Taken together, our findings indicate that most humans express only a nonfunctional isoform of P2X5, which is in stark contrast to what is seen in other vertebrate species in which P2X5 has been studied, from which only the full-length isoform is known.

  11. IUGR increases chromatin-remodeling factor Brg1 expression and binding to GR exon 1.7 promoter in newborn male rat hippocampus.

    Science.gov (United States)

    Ke, Xingrao; McKnight, Robert A; Gracey Maniar, Lia E; Sun, Ying; Callaway, Christopher W; Majnik, Amber; Lane, Robert H; Cohen, Susan S

    2015-07-15

    Intrauterine growth restriction (IUGR) increases the risk for neurodevelopment delay and neuroendocrine reprogramming in both humans and rats. Neuroendocrine reprogramming involves the glucocorticoid receptor (GR) gene that is epigenetically regulated in the hippocampus. Using a well-characterized rodent model, we have previously shown that IUGR increases GR exon 1.7 mRNA variant and total GR expressions in male rat pup hippocampus. Epigenetic regulation of GR transcription may involve chromatin remodeling of the GR gene. A key chromatin remodeler is Brahma-related gene-1(Brg1), a member of the ATP-dependent SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling complex. Brg1 regulates gene expression by affecting nucleosome repositioning and recruiting transcriptional components to target promoters. We hypothesized that IUGR would increase hippocampal Brg1 expression and binding to GR exon 1.7 promoter, as well as alter nucleosome positioning over GR promoters in newborn male pups. Further, we hypothesized that IUGR would lead to accumulation of specificity protein 1 (Sp1) and RNA pol II at GR exon 1.7 promoter. Indeed, we found that IUGR increased Brg1 expression and binding to GR exon 1.7 promoter. We also found that increased Brg1 binding to GR exon 1.7 promoter was associated with accumulation of Sp1 and RNA pol II carboxy terminal domain pSer-5 (a marker of active transcription). Furthermore, the transcription start site of GR exon 1.7 was located within a nucleosome-depleted region. We speculate that changes in hippocampal Brg1 expression mediate GR expression and subsequently trigger neuroendocrine reprogramming in male IUGR rats. Copyright © 2015 the American Physiological Society.

  12. Evolution of alternative splicing regulation: changes in predicted exonic splicing regulators are not associated with changes in alternative splicing levels in primates.

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    Manuel Irimia

    Full Text Available Alternative splicing is tightly regulated in a spatio-temporal and quantitative manner. This regulation is achieved by a complex interplay between spliceosomal (trans factors that bind to different sequence (cis elements. cis-elements reside in both introns and exons and may either enhance or silence splicing. Differential combinations of cis-elements allows for a huge diversity of overall splicing signals, together comprising a complex 'splicing code'. Many cis-elements have been identified, and their effects on exon inclusion levels demonstrated in reporter systems. However, the impact of interspecific differences in these elements on the evolution of alternative splicing levels has not yet been investigated at genomic level. Here we study the effect of interspecific differences in predicted exonic splicing regulators (ESRs on exon inclusion levels in human and chimpanzee. For this purpose, we compiled and studied comprehensive datasets of predicted ESRs, identified by several computational and experimental approaches, as well as microarray data for changes in alternative splicing levels between human and chimpanzee. Surprisingly, we found no association between changes in predicted ESRs and changes in alternative splicing levels. This observation holds across different ESR exon positions, exon lengths, and 5' splice site strengths. We suggest that this lack of association is mainly due to the great importance of context for ESR functionality: many ESR-like motifs in primates may have little or no effect on splicing, and thus interspecific changes at short-time scales may primarily occur in these effectively neutral ESRs. These results underscore the difficulties of using current computational ESR prediction algorithms to identify truly functionally important motifs, and provide a cautionary tale for studies of the effect of SNPs on splicing in human disease.

  13. Common exonic missense variants in the C2 domain of the human KIBRA protein modify lipid binding and cognitive performance.

    Science.gov (United States)

    Duning, K; Wennmann, D O; Bokemeyer, A; Reissner, C; Wersching, H; Thomas, C; Buschert, J; Guske, K; Franzke, V; Flöel, A; Lohmann, H; Knecht, S; Brand, S-M; Pöter, M; Rescher, U; Missler, M; Seelheim, P; Pröpper, C; Boeckers, T M; Makuch, L; Huganir, R; Weide, T; Brand, E; Pavenstädt, H; Kremerskothen, J

    2013-06-18

    The human KIBRA gene has been linked to human cognition through a lead intronic single-nucleotide polymorphism (SNP; rs17070145) that is associated with episodic memory performance and the risk to develop Alzheimer's disease. However, it remains unknown how this relates to the function of the KIBRA protein. Here, we identified two common missense SNPs (rs3822660G/T [M734I], rs3822659T/G [S735A]) in exon 15 of the human KIBRA gene to affect cognitive performance, and to be in almost complete linkage disequilibrium with rs17070145. The identified SNPs encode variants of the KIBRA C2 domain with distinct Ca(2+) dependent binding preferences for monophosphorylated phosphatidylinositols likely due to differences in the dynamics and folding of the lipid-binding pocket. Our results further implicate the KIBRA protein in higher brain function and provide direction to the cellular pathways involved.

  14. Common exonic missense variants in the C2 domain of the human KIBRA protein modify lipid binding and cognitive performance

    Science.gov (United States)

    Duning, K; Wennmann, D O; Bokemeyer, A; Reissner, C; Wersching, H; Thomas, C; Buschert, J; Guske, K; Franzke, V; Flöel, A; Lohmann, H; Knecht, S; Brand, S-M; Pöter, M; Rescher, U; Missler, M; Seelheim, P; Pröpper, C; Boeckers, T M; Makuch, L; Huganir, R; Weide, T; Brand, E; Pavenstädt, H; Kremerskothen, J

    2013-01-01

    The human KIBRA gene has been linked to human cognition through a lead intronic single-nucleotide polymorphism (SNP; rs17070145) that is associated with episodic memory performance and the risk to develop Alzheimer's disease. However, it remains unknown how this relates to the function of the KIBRA protein. Here, we identified two common missense SNPs (rs3822660G/T [M734I], rs3822659T/G [S735A]) in exon 15 of the human KIBRA gene to affect cognitive performance, and to be in almost complete linkage disequilibrium with rs17070145. The identified SNPs encode variants of the KIBRA C2 domain with distinct Ca2+ dependent binding preferences for monophosphorylated phosphatidylinositols likely due to differences in the dynamics and folding of the lipid-binding pocket. Our results further implicate the KIBRA protein in higher brain function and provide direction to the cellular pathways involved. PMID:23778582

  15. Novel deletion encompassing exons 5-12 of the UBE3A gene in a girl with Angelman syndrome.

    Science.gov (United States)

    Beleza-Meireles, Ana; Cerqueira, Rita; Sousa, Sérgio B; Palmeiro, Aida; Ramos, Lina

    2011-01-01

    Angelman syndrome (AS) is characterised by severe developmental delay, severe speech impairment, gait ataxia and/or limb tremor and a unique behavioural phenotype. The diagnosis of AS is based on a combination of clinical features and molecular genetic testing. Currently, molecular genetic testing (methylation analysis and UBE3A sequence analysis) identifies anomalies in about 90% of individuals. The aetiology of the remaining 10% is still unknown. We report a novel deletion encompassing the exons 5-12 of the UBE3A gene in a girl with AS, identified by MLPA (Multiplex Ligation-dependent Probe Amplification), which was not detected by the conventional diagnostic protocol. We propose that copy number analysis of the UBE3A gene should be considered in individuals whose clinical examination is strongly suggestive of AS, after more common mechanisms have been excluded. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  16. Molecular genetic analysis of cereal β-amylase genes using exon-primed intron-crossing (EPIC PCR

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    Stratula Olga

    2014-01-01

    Full Text Available The proteins encoded by cereal β-amylase genes Bamy1 and Bamy2 genes play an important role in seedling germination and in the brewing process. Here, we use exon-primed intron-crossing (EPIC to analyse Bamy1 and Bamy2 genetic diversity among 38 accessions belonging to six Poaceae tribes. DNA sequence alignment of multiple Poaceae species β-amylase sequences allowed design of EPIC primers that simultaneously amplify Bamy1 and Bamy2 in all the cereal species investigated. The genetic variation observed in the samples investigated is analysed and discussed, and illustrates the effectiveness of this approach for intra- and interspecific analysis in plant species.

  17. Deletion of exon 26 of the dystrophin gene is associated with a mild Becker muscular dystrophy phenotype

    DEFF Research Database (Denmark)

    Witting, Nanna; Duno, Morten; Vissing, John

    2011-01-01

    calf hypertrophy was noted. Creatine kinase was normal or raised maximally to 500 U/l. The muscle biopsy was myopathic with increased fiber size variation and many internal nuclei, but no dystrophy. No comorbidity was found. In both cases, western blot showed a reduced dystrophin band. Genetic...... associated with an exon 26 deletion. The proband, a 23-year-old man, had slightly delayed motor milestones, walking 1 1/2 years old. He had no complaints of muscle weakness, but had muscle pain. Clinical examination revealed no muscle wasting or loss of power, but his CK was 1500-7000 U/l. Muscle biopsy...... showed dystrophic changes. He had comorbidity with dystonia, slight mental retardation, low stature and neuropathy. The brother of the proband's mother came to medical attention when he was 43 years old. He complained about muscle pain. On examination, a MRC grade 4+ hip extention palsy and a discrete...

  18. Conservation of the Exon-Intron Structure of Long Intergenic Non-Coding RNA Genes in Eutherian Mammals

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    Diana Chernikova

    2016-07-01

    Full Text Available The abundance of mammalian long intergenic non-coding RNA (lincRNA genes is high, yet their functions remain largely unknown. One possible way to study this important question is to use large-scale comparisons of various characteristics of lincRNA with those of protein-coding genes for which a large body of functional information is available. A prominent feature of mammalian protein-coding genes is the high evolutionary conservation of the exon-intron structure. Comparative analysis of putative intron positions in lincRNA genes from various mammalian genomes suggests that some lincRNA introns have been conserved for over 100 million years, thus the primary and/or secondary structure of these molecules is likely to be functionally important.

  19. Deletion of exon 26 of the dystrophin gene is associated with a mild Becker muscular dystrophy phenotype

    DEFF Research Database (Denmark)

    Witting, Nanna; Duno, Morten; Vissing, John

    2011-01-01

    calf hypertrophy was noted. Creatine kinase was normal or raised maximally to 500 U/l. The muscle biopsy was myopathic with increased fiber size variation and many internal nuclei, but no dystrophy. No comorbidity was found. In both cases, western blot showed a reduced dystrophin band. Genetic...... associated with an exon 26 deletion. The proband, a 23-year-old man, had slightly delayed motor milestones, walking 1 1/2 years old. He had no complaints of muscle weakness, but had muscle pain. Clinical examination revealed no muscle wasting or loss of power, but his CK was 1500-7000 U/l. Muscle biopsy...... showed dystrophic changes. He had comorbidity with dystonia, slight mental retardation, low stature and neuropathy. The brother of the proband's mother came to medical attention when he was 43 years old. He complained about muscle pain. On examination, a MRC grade 4+ hip extention palsy and a discrete...

  20. Combined detection of gene mutation with PCR-SSCP and PCR sequencing on exon 7 of neurofibromatosis 2 gene in patients with sporadic Schwannoma%联合应用PCR-SSCP和PCR产物测序检测神经鞘瘤患者NF2基因Exon7突变及其意义

    Institute of Scientific and Technical Information of China (English)

    薛跃华; 林亦海; 李招云; 张黎明; 应炎斌

    2011-01-01

    目的 研究散发神经鞘瘤患者中Ⅱ型多发神经纤维瘤病基因(neurofibromatosis2,NF2)外显子7(Exon7)的突变及意义.方法 采用聚合酶链反应单链构象多态性技术和DNA测序技术检测25例神经鞘瘤中NF2基因Exon7突变.结果 25例神经鞘瘤患者中共发现3例NF2基因Exon7突变,均发生于脊神经鞘瘤,其中剪切受体位点突变1例、移码突变2例.结论 NF2基因Exon7突变可能是脊神经鞘瘤发生的关键因素.%Objective To detect gene mutation on exon 7 of neurofbromatos is 2 (NF2) in patients with sporadic Schwannoma.Methods Gene mutations on exon 7 of NF 2 gene in 25 cases of Schwannoma were detected by PCR- SSCP and DNA sequence.Results Three mutations were found in 25 cases of Schwannoma, including one splice donor mutation and two frameshift mutations in spinal tumors.Conclusion Mutations on exon7 of NF2 gene might be one of the critical factors in tumorogenesis of spinal Schwannoma.

  1. Clinical implications of cytosine deletion of exon 5 of P53 gene in non small cell lung cancer patients

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    Rashid Mir

    2016-01-01

    Full Text Available Aim: Lung cancer is considered to be the most common cancer in the world. In humans, about 50% or more cancers have a mutated tumor suppressor p53 gene thereby resulting in accumulation of p53 protein and losing its function to activate the target genes that regulate the cell cycle and apoptosis. Extensive research conducted in murine cancer models with activated p53, loss of p53, or p53 missense mutations have facilitated researchers to understand the role of this key protein. Our study was aimed to evaluate the frequency of cytosine deletion in nonsmall cell lung cancer (NSCLC patients. Methods: One hundred NSCLC patients were genotyped for P53 (exon5, codon168 cytosine deletion leading to loss of its function and activate the target genes by allele-specific polymerase chain reaction. The P53 cytosine deletion was correlated with all the clinicopathological parameters of the patients. Results and Analysis: 59% cases were carrying P53 cytosine deletion. Similarly, the significantly higher incidence of cytosine deletion was reported in current smokers (75% in comparison to exsmoker and nonsmoker. Significantly higher frequency of cytosine deletion was reported in adenocarcinoma (68.08% than squamous cell carcinoma (52.83%. Also, a significant difference was reported between p53 cytosine deletion and metastasis (64.28%. Further, the majority of the cases assessed for response carrying P53 cytosine deletion were found to show faster disease progression. Conclusion: The data suggests that there is a significant association of the P53 exon 5 deletion of cytosine in codon 168 with metastasis and staging of the disease.

  2. Exon-level transcriptome profiling in murine breast cancer reveals splicing changes specific to tumors with different metastatic abilities.

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    Amandine Bemmo

    Full Text Available BACKGROUND: Breast cancer is the second most frequent type of cancer affecting women. We are increasingly aware that changes in mRNA splicing are associated with various characteristics of cancer. The most deadly aspect of cancer is metastasis, the process by which cancer spreads from the primary tumor to distant organs. However, little is known specifically about the involvement of alternative splicing in the formation of macroscopic metastases. Our study investigates transcript isoform changes that characterize tumors of different abilities to form growing metastases. METHODS AND FINDINGS: To identify alternative splicing events (ASEs that are associated with the fully metastatic phenotype in breast cancer, we used Affymetrix Exon Microarrays to profile mRNA isoform variations genome-wide in weakly metastatic (168FARN and 4T07 and highly metastatic (4T1 mammary carcinomas. Statistical analysis identified significant expression changes in 7606 out of 155,994 (4% exons and in 1725 out of 189,460 (1% intronic regions, which affect 2623 out of 16,654 (16% genes. These changes correspond to putative alternative isoforms-several of which are novel-that are differentially expressed between tumors of varying metastatic phenotypes. Gene pathway analysis showed that 1224 of genes expressing alternative isoforms were involved in cell growth, cell interactions, cell proliferation, cell migration and cell death and have been previously linked to cancers and genetic disorders. We chose ten predicted splice variants for RT-PCR validation, eight of which were successfully confirmed (MED24, MFI2, SRRT, CD44, CLK1 and HNRNPH1. These include three novel intron retentions in CD44, a gene in which isoform variations have been previously associated with the metastasis of several cancers. CONCLUSION: Our findings reveal that various genes are differently spliced and/or expressed in association with the metastatic phenotype of tumor cells. Identification of

  3. Role of accelerated segment switch in exons to alter targeting (ASSET in the molecular evolution of snake venom proteins

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    Kini R Manjunatha

    2009-06-01

    Full Text Available Abstract Background Snake venom toxins evolve more rapidly than other proteins through accelerated changes in the protein coding regions. Previously we have shown that accelerated segment switch in exons to alter targeting (ASSET might play an important role in its functional evolution of viperid three-finger toxins. In this phenomenon, short sequences in exons are radically changed to unrelated sequences and hence affect the folding and functional properties of the toxins. Results Here we analyzed other snake venom protein families to elucidate the role of ASSET in their functional evolution. ASSET appears to be involved in the functional evolution of three-finger toxins to a greater extent than in several other venom protein families. ASSET leads to replacement of some of the critical amino acid residues that affect the biological function in three-finger toxins as well as change the conformation of the loop that is involved in binding to specific target sites. Conclusion ASSET could lead to novel functions in snake venom proteins. Among snake venom serine proteases, ASSET contributes to changes in three surface segments. One of these segments near the substrate binding region is known to affect substrate specificity, and its exchange may have significant implications for differences in isoform catalytic activity on specific target protein substrates. ASSET therefore plays an important role in functional diversification of snake venom proteins, in addition to accelerated point mutations in the protein coding regions. Accelerated point mutations lead to fine-tuning of target specificity, whereas ASSET leads to large-scale replacement of multiple functionally important residues, resulting in change or gain of functions.

  4. 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.

  5. Mutation analysis of exon1 of bone morphogenetic protein-15 gene in Iranian patients with polycystic ovarian syndrome

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    Anahita Mehdizadeh

    2016-08-01

    Full Text Available Background: With the prevalence of 6-10%, polycystic ovarian syndrome (PCOS is considered the most common endocrinological disorder affecting women in their reproductive age. It has been suggested that genetic factors participate in the development of PCOS. Follicular development has been considered as one of the impaired processes in PCOS. Bone morphogenetic protein-15 (BMP-15 gene is a candidate gene in follicular development and its variants may play role in pathogenesis of PCOS. Objective: To investigate whether BMP-15 gene mutations are present in Iranian women with PCOS. Materials and Methods: In this cross-sectional study 5 ml venous blood samples was taken from 70 PCOS women referring to Afzalipour Hospital, Kerman University of Medical Sciences, Kerman, Iran, between January to December 2014. Genomic DNA was extracted from the blood sample by salting out method. Then a set of PCR reactions for exon1 of BMP-15 gene was performed using specific primers followed by genotyping with direct sequencing. Results: Two different polymorphisms were found in the gene under study. In total 20 patients (28.6% were heterozygote (C/G, and 2 patients (2.86% were homozygous (G/G for c.-9C>G in 5´UTR promoter region of BMP-15 gene (rs3810682. In addition, in the coding region of exon1, three patients (4.3% were heterozygote (G/A for c.A308G (rs41308602. Two PCOS patients (2.86% appeared to have both c.-9C>G (C/G and c.A308G (G/A variants simultaneously. Conclusion: Our research detected two polymorphisms of BMP-15 gene among PCOS patients, indicating that even though it cannot be concluded that variants of BMP-15 gene are the principal cause of polycystic ovarian syndrome; they could be involved in pathogenic process in development of PCOS.

  6. DVL3 Alleles Resulting in a −1 Frameshift of the Last Exon Mediate Autosomal-Dominant Robinow Syndrome

    Science.gov (United States)

    White, Janson J.; Mazzeu, Juliana F.; Hoischen, Alexander; Bayram, Yavuz; Withers, Marjorie; Gezdirici, Alper; Kimonis, Virginia; Steehouwer, Marloes; Jhangiani, Shalini N.; Muzny, Donna M.; Gibbs, Richard A.; van Bon, Bregje W.M.; Sutton, V. Reid; Lupski, James R.; Brunner, Han G.; Carvalho, Claudia M.B.

    2016-01-01

    Robinow syndrome is a rare congenital disorder characterized by mesomelic limb shortening, genital hypoplasia, and distinctive facial features. Recent reports have identified, in individuals with dominant Robinow syndrome, a specific type of variant characterized by being uniformly located in the penultimate exon of DVL1 and resulting in a −1 frameshift allele with a premature termination codon that escapes nonsense-mediated decay. Here, we studied a cohort of individuals who had been clinically diagnosed with Robinow syndrome but who had not received a molecular diagnosis from variant studies of DVL1, WNT5A, and ROR2. Because of the uniform location of frameshift variants in DVL1-mediated Robinow syndrome and the functional redundancy of DVL1, DVL2, and DVL3, we elected to pursue direct Sanger sequencing of the penultimate exon of DVL1 and its paralogs DVL2 and DVL3 to search for potential disease-associated variants. Remarkably, targeted sequencing identified five unrelated individuals harboring heterozygous, de novo frameshift variants in DVL3, including two splice acceptor mutations and three 1 bp deletions. Similar to the variants observed in DVL1-mediated Robinow syndrome, all variants in DVL3 result in a −1 frameshift, indicating that these highly specific alterations might be a common cause of dominant Robinow syndrome. Here, we review the current knowledge of these peculiar variant alleles in DVL1- and DVL3-mediated Robinow syndrome and further elucidate the phenotypic features present in subjects with DVL1 and DVL3 frameshift mutations. PMID:26924530

  7. Altered Striatal Synaptic Function and Abnormal Behaviour in Shank3 Exon4-9 Deletion Mouse Model of Autism.

    Science.gov (United States)

    Jaramillo, Thomas C; Speed, Haley E; Xuan, Zhong; Reimers, Jeremy M; Liu, Shunan; Powell, Craig M

    2016-03-01

    Shank3 is a multi-domain, synaptic scaffolding protein that organizes proteins in the postsynaptic density of excitatory synapses. Clinical studies suggest that ∼ 0.5% of autism spectrum disorder (ASD) cases may involve SHANK3 mutation/deletion. Patients with SHANK3 mutations exhibit deficits in cognition along with delayed/impaired speech/language and repetitive and obsessive/compulsive-like (OCD-like) behaviors. To examine how mutation/deletion of SHANK3 might alter brain function leading to ASD, we have independently created mice with deletion of Shank3 exons 4-9, a region implicated in ASD patients. We find that homozygous deletion of exons 4-9 (Shank3(e4-9) KO) results in loss of the two highest molecular weight isoforms of Shank3 and a significant reduction in other isoforms. Behaviorally, both Shank3(e4-9) heterozygous (HET) and Shank3(e4-9) KO mice display increased repetitive grooming, deficits in novel and spatial object recognition learning and memory, and abnormal ultrasonic vocalizations. Shank3(e4-9) KO mice also display abnormal social interaction when paired with one another. Analysis of synaptosome fractions from striata of Shank3(e4-9) KO mice reveals decreased Homer1b/c, GluA2, and GluA3 expression. Both Shank3(e4-9) HET and KO demonstrated a significant reduction in NMDA/AMPA ratio at excitatory synapses onto striatal medium spiny neurons. Furthermore, Shank3(e4-9) KO mice displayed reduced hippocampal LTP despite normal baseline synaptic transmission. Collectively these behavioral, biochemical and physiological changes suggest Shank3 isoforms have region-specific roles in regulation of AMPAR subunit localization and NMDAR function in the Shank3(e4-9) mutant mouse model of autism.

  8. Mutation analysis of exon1 of bone morphogenetic protein-15 gene in Iranian patients with polycystic ovarian syndrome

    Science.gov (United States)

    Mehdizadeh, Anahita; Sheikhha, Mohammad Hasan; Kalantar, Seyed Mehdi; Aali, Bibi Shahnaz; Ghanei, Azam

    2016-01-01

    Background: With the prevalence of 6-10%, polycystic ovarian syndrome (PCOS) is considered the most common endocrinological disorder affecting women in their reproductive age. It has been suggested that genetic factors participate in the development of PCOS. Follicular development has been considered as one of the impaired processes in PCOS. Bone morphogenetic protein-15 (BMP-15) gene is a candidate gene in follicular development and its variants may play role in pathogenesis of PCOS. Objective: To investigate whether BMP-15 gene mutations are present in Iranian women with PCOS. Materials and Methods: In this cross-sectional study 5 ml venous blood samples was taken from 70 PCOS women referring to Afzalipour Hospital, Kerman University of Medical Sciences, Kerman, Iran, between January to December 2014. Genomic DNA was extracted from the blood sample by salting out method. Then a set of PCR reactions for exon1 of BMP-15 gene was performed using specific primers followed by genotyping with direct sequencing. Results: Two different polymorphisms were found in the gene under study. In total 20 patients (28.6%) were heterozygote (C/G), and 2 patients (2.86%) were homozygous (G/G) for c.-9C>G in 5´UTR promoter region of BMP-15 gene (rs3810682). In addition, in the coding region of exon1, three patients (4.3%) were heterozygote (G/A) for c.A308G (rs41308602). Two PCOS patients (2.86%) appeared to have both c.-9C>G (C/G) and c.A308G (G/A) variants simultaneously. Conclusion: Our research detected two polymorphisms of BMP-15 gene among PCOS patients, indicating that even though it cannot be concluded that variants of BMP-15 gene are the principal cause of polycystic ovarian syndrome; they could be involved in pathogenic process in development of PCOS. PMID:27679828

  9. Growth hormone receptor exon 3 isoforms may have no importance in the clinical setting of multiethnic Brazilian acromegaly patients.

    Science.gov (United States)

    de Oliveira Machado, Evelyn; Lima, Carlos Henrique Azeredo; Ogino, Liana Lumi; Kasuki, Leandro; Gadelha, Mônica R

    2016-08-01

    Acromegaly is associated with significant morbidity and increased mortality, but has a variable severity phenotype. The presence of the exon 3-deleted isoform of the growth hormone receptor (d3-GHR) may influence the disease phenotype and treatment outcomes, including the frequency of biochemical discordance after medical treatment. The objective of this study was to analyze the influence of the d3-GHR isoform on clinical and biochemical characteristics and in the treatment outcomes of Brazilian multiethnic acromegaly patients. We retrospectively analyzed our acromegaly outpatient clinic databank and collected demographic, clinical, biochemical and treatment outcome data from those patients who agreed to participate in the study. A blood sample was collected from all patients, the DNA was extracted and the GHR isoforms were evaluated by PCR, with the full length (fl)-GHR represented by a 935-bp fragment and the d3-GHR represented by a 532-bp fragment. A total of 121 patients were included. Fifty-six patients (46.3 %) were full-length homozygous (fl/fl), 48 (39.7 %) were heterozygous (fl/d3) and 17 (14.0 %) were d3-GHR homozygous (d3/d3). There was no difference between patients homozygous for the fl isoform and those harboring at least one d3-GHR allele in the demographic, clinical and biochemical data or in the treatment outcomes, including somatostatin receptor ligands (SRL) monotherapy, combination therapy with SRL and cabergoline and pegvisomant treatment. There was also no difference between the groups for the frequency of GH and IGF-I discordance after medical treatment. GHR exon 3 genotyping appears to have no clinical significance, at least in Brazilian acromegaly patients.

  10. Expression and new exon mutations of the human Beta defensins and their association on colon cancer development.

    Directory of Open Access Journals (Sweden)

    Abdelhabib Semlali

    Full Text Available The development of cancer involves genetic predisposition and a variety of environmental exposures. Genome-wide linkage analyses provide evidence for the significant linkage of many diseases to susceptibility loci on chromosome 8p23, the location of the human defensin gene cluster. Human β-defensins (hBDs are important molecules of innate immunity. This study was designed to analyze the expression and genetic variations in hBDs (hBD-1, hBD-2, hBD-3 and hBD-4 and their putative association with colon cancer. hBD gene expression and relative protein expression were evaluated by Real-Time polymerase chain reaction (qPCR and immunohistochemistry, respectively, from 40 normal patients and 40 age-matched patients with colon cancer in Saudi Arabia. In addition, hBD polymorphisms were genotyped by exon sequencing and by promoter methylation. hBD-1, hBD-2, hBD-3 and hBD-4 basal messenger RNA expression was significantly lower in tumor tissues compared with normal tissues. Several insertion mutations were detected in different exons of the analyzed hBDs. However, no methylation in any hBDs promoters was detected because of the limited number of CpG islands in these regions. We demonstrated for the first time a link between hBD expression and colon cancer. This suggests that there is a significant link between innate immunity deregulation through disruption of cationic peptides (hBDs and the potential development of colon cancer.

  11. X-linked familial exudative vitreoretinopathy caused by an arginine to leucine substitution in exon 3 of the Norrie gene

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K.; Perry, Y.M.; Ferrell, R.E. [Univ. of Pittsburg, PA (United States)] [and others

    1994-09-01

    Familial exudative vitreoretinopathy (FEVR) is a disorder characterized by abnormal vascularization of the peripheral retina affecting both the retina and the vitreous body. This is a bilateral disorder and leads to a clinical phenotype resembling retinopathy of prematurity, but affected individuals experience a normal gestational period, and they do not have a history of oxygen therapy. Manifestations of the disorder may include retinal folds, retinal traction, sub- or intraretinal exudates, and in sev