DOCSLIB.ORG

SHORT PAPER 1. INTRODUCTION the Specific Locus Test in Mice Can

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
SHORT PAPER 1. INTRODUCTION the Specific Locus Test in Mice Can Jpn. J. Genet. (1983) 58, pp. 263-267 SHORT PAPER Genetic analysis of mutants in mice induced by N-ethyl-N-nitrosourea BY Tetsuro MUROTAand Tohru SHIBUYA Laboratory of Genetics, Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257 (Received December 10, 1982) ABSTRACT Specific locus tests of the effects of N-ethyl-N-nitrosourea (ENU) on mouse spermatogonia using visible loci and hemoglobin beta-chain (Hbb) locus have been performed. Male wild-type (C3Hf/He) mice were injected intraperito- neally with ENU. Eight weeks after injection, the males were mated with tester strain females (PW) homozygous for six visible recessive genes. Ten visible and 2 hemoglobin mutants were obtained. The mutation frequency was 60.3 x 10-5/locus/generation. These mutations were all heritable, and nine out of ten mutations were viable under homozygous conditions. The results suggest that the mutations induced by ENU on spermatogonia of mice might have resulted from events at the genic rather than the chromosomal level. 1. INTRODUCTION The specific locus test in mice can be used to detect gene mutations caused by various mutagens. Analysis of germ cell mutations in mice can provide important information for estimation of the genetic risk of environmental mutagens to humans. Generally, the specific locus test in mice has been mainly applied for the detection of visible recessive mutations (Russell 1951). This test is advantageous in that (1) it can accurately determine the induced muta- tion frequency at a given locus in germ cells, (2) the differential stage sensi- tivity to chemical mutagens in in vivo germ cells can be determined and (3) the nature of the mutations induced can be characterized. Recently, the detection of mutations at enzyme and/or protein loci by means of electro- phoretic techniques has been developed. Most enzymes in mice are rather similar to those of humans, so that the induction of mutations at the enzyme level in mice could provide important information to estimate the genetic risk of environmental mutagens to humans. The nature of induced mutations at these loci was investigated in detail by biochemical and molecular methods. Russell et al. (1979) indicated that ENU has strong mutagenic activity for inducing visible recessive mutations in mouse spermatogonia. A study of 264 T. MUROTA and T. SHIBUYA mutagenicity at visible loci and hemoglobin beta-chain (Hbb) locus in sper- matogonia of mice after treatment with ENU was therefore carried out, and many mutants were obtained. Genetic analysis of these mutants should provide important information regarding the types of genetic damage induced by ENU. In this paper, the results of specific locus tests with ENU in mice and a genetic analysis of the mutants are reported. 2. MATERIALS AND METHODS Male 9-week-old C3Hf /He mice were given a single dose of N-ethyl-N- nitrosourea (ENU: Nakarai Chemical, Ltd., Japan) dissolved in 1/15M phosphate buffer adjusted to pH 6.0 at a concentration of 150 mg/kg. A volume of 0.5 ml per 25 g body weight was administered intraperitoneally. No treatment was given to control males. From 8 weeks after treatment, each male was mated with 12- to 16-week-old tester strain females (PW), homozygous for six visible recessive genes, a/a, b/b, cch/cch,d/d, se/se and p/p, as established by Tutikawa and Harada (1981). The pregnant females were separated and allowed to deliver offspring. The offspring were weaned at about 21 days of age and then scored for mutation at the six loci. The analysis of Hbb locus mutations was carried out by means of Titan III cellulose acetate (Helena Laboratories, U.S.A.) electrophoresis of fresh hemolysates and alkylated hemolysates treated with iodoacetate. Electrophoresis was performed according to the method described by Takahashi et al. (1978). The preparation of samples for electro- phoretic studies was described elsewhere (Murota et al., 1982). The genotypes of C3Hf /He and PW were Hbbd/Hbbd and Hbb'/Hbb', respectively. The allelism and viability tests on the visible mutants were performed according to the method described by Searle (1977). For the viability test of the mutant at the Hbb locus, they were backcrossed to the marker stock PW, and the result- ant backcross F1 offspring, classified as heterozygous mutants, were mated inter se. The homozygous viability of these mutations was judged on the basis of whether or not homozygous mutants were obtained by crossing of these heterozygous mutants inter se. 3. RESULTSAND DISCUSSION The results of specific locus tests with ENU are shown in Table 1. In the treated group, 2916 offspring were obtained, among which 2400 offspring were examined at the Hbb locus. Ten visible locus mutants and two Hbb locus mutants were obtained. The overall mutation frequency was calculated to be 60.3 X 10-5/locus/generation with 95% confidence intervals of 31.2 to 105.3 X 10-5. This value corresponds well with the results reported by Russell et al. (1982). In the control group, no mutation was detected among 1731 offspring. In Table 2, the results of allelism and viability tests on the detected mutants are listed. Specific locus tests in mice with ENU 265 Table 1. Mutation frequency at specific loci in the offspring of male mice treated withFlN-ethyl-N-nitrosourea *: The numbers in parentheses indicate the numbers of offsping at the Hbb locus . Table 2. Distribution among specific loci of mutations induced in spermatogonia in mice by N-ethyl-N-nitrosourea, and thier viability under homozygous conditions * N . T.: Not tested for v iability. The locus distribution of the mutants was as follows: b locus, 3; c locus, 2; d locus, 3; p locus, 2; and Hbb locus, 2. As shown in the Table, nine out of ten mutants were viable under homozygous conditions. Two female mutants died before the viability test could be performed, so that the viability could not be determined. Chemicals which are known to induce specific locus mutations on sper- matogonia in the mouse specific locus test include triethylenemelamine (Cattanach 1966), mitomycin C (Ehling 1974), procarbazine (Ehling and Neu- hauser 1979) and ENU (Russell et al. 1979) . The induced mutation frequency of ENU was higher than that of the other chemical mutagens. The frequencies of homozygous viable mutations induced by mitomycin C (Ehling 1980) and procarbazine (Ehling and Neuhauser 1979) were reported to be 75% and 76%, respectively. The origin of mutations induced by these chemicals might have been mainly base-pair changes. ENU induces a high frequency of homozygous viable mutations (90%) in accord with the above view. In radiation muta- genesis, however, the frequency of X-ray-induced viable mutants in spermato- gonia was only 23% (Russell and Russell 1959), suggesting that mutations induced by X-rays in spermatogonia might include some chromosomal abnor- malities. Similar events were also observed in experiments using gamma-rays and fission neutrons (Batchelor et al. 1966). The frequency of homozygous 266 T. MUROTA and T. SHIBUYA viable mutations was clearly different between chemically-induced and radia- tion-induced mutations in spermatogonia. In the post-spermatogonial stage, procarbazine (Ehling and Neuhauser 1979) and methyl methanesulf onate (Ehling 1978) are known to induce specific locus mutations. The viable muta- tions amounted to 33% (Ehling and Neuhauser 1979) and 12% (Ehling 1980), respectively. The frequency of specific locus mutations which were viable under homozygous conditions was clearly dependent on the germ cell stage tested, i.e., post-spermatogonia and spermatogonia. It is likely that qualitative differences of specific locus mutations induced by some chemicals in post- spermatogonia and spermatogonia may exist. In mice, three alleles, Hbb', Hbbd and Hbbp have been reported at the Hbb locus which may code the structure of hemoglobin beta-chain polypeptides. It is well known that the amino acid composition of the beta-chain is different for each allele (Gilman 1974). Both Hbb' and Hbbd are found in most inbred strains, but Hbbp is rare (Staats 1980). Two mutants at Hbb locus were obtained in this experiment. These mutations were heritable and viable under homozygous conditions. One of the mutants was observed as a change in the mobility of the bands on electrophoresis (Murota et al. 1982) . The mobility of the bands was similar to that of Pon which carrier Hbb alleles under homo- zygous conditions (Watanabe et al. 1976). In the second mutant, new bands were observed. This observation suggested that the mutation had not origi- nated from Hbb locus, but from Hba locus. The other electrophoresic technique described by Chernoff and Pettit (1964) would account for this events. This may represent a gene mutations like the mutations observed at specific loci. We are grateful to Dr. Akio Murakami, National Institute of Genetics, for a critical reading of the manuscript, and to Dr. Kiyoshi Tutikawa, National Institute of Genetics, for his valuable comments. We are also indebted to Drs. Koroku Hashimoto and Shigeo Iwahara of Hatano Research Institute for their constant encouragement during the present study. REFERENCES BATCHELOR,A. L., PHILLIPS, R. J. S. and SEARLE, A. G. (1966) A comparison of the mutagenic effectiveness of chronic neutron- and 7-irradiation of mouse spermatogonia. Mutation Res. 3, 218-229. CATTANACH,B. M. (1966) Chemically induced mutations in mice. Mutation Res. 3, 346-353. CHERNOFF, A. L. and PETTIT, N. M. (1964) The amino acid composition of hemoglobin. III. A qualitative method for identifying abnormalities of the polypeptide chains of hemoglobin. Blood 24, 740-756. EHLING, U. H. (1974) Differential spermatogenic response of mice to the induction of mutations by antineoplastic drug. Mutation Res. 26, 285-295. EHLING, U. H. (1978) Specific-locus mutations in mice.
Load more

Recommended publications
  • Detailed Review Paper on Retinoid Pathway Signalling
    1 1 Detailed Review Paper on Retinoid Pathway Signalling 2 December 2020 3 2 4 Foreword 5 1. Project 4.97 to develop a Detailed Review Paper (DRP) on the Retinoid System 6 was added to the Test Guidelines Programme work plan in 2015. The project was 7 originally proposed by Sweden and the European Commission later joined the project as 8 a co-lead. In 2019, the OECD Secretariat was added to coordinate input from expert 9 consultants. The initial objectives of the project were to: 10 draft a review of the biology of retinoid signalling pathway, 11 describe retinoid-mediated effects on various organ systems, 12 identify relevant retinoid in vitro and ex vivo assays that measure mechanistic 13 effects of chemicals for development, and 14 Identify in vivo endpoints that could be added to existing test guidelines to 15 identify chemical effects on retinoid pathway signalling. 16 2. This DRP is intended to expand the recommendations for the retinoid pathway 17 included in the OECD Detailed Review Paper on the State of the Science on Novel In 18 vitro and In vivo Screening and Testing Methods and Endpoints for Evaluating 19 Endocrine Disruptors (DRP No 178). The retinoid signalling pathway was one of seven 20 endocrine pathways considered to be susceptible to environmental endocrine disruption 21 and for which relevant endpoints could be measured in new or existing OECD Test 22 Guidelines for evaluating endocrine disruption. Due to the complexity of retinoid 23 signalling across multiple organ systems, this effort was foreseen as a multi-step process.
    [Show full text]
  • Mice Exposed to N-Ethyl-N-Nitrosourea T
    Proc. Nati. Acad. Sci. USA Vol. 89, pp. 7866-7870, September 1992 Genetics Mutational spectrum at the Hprt locus in splenic T cells of B6C3F1 mice exposed to N-ethyl-N-nitrosourea T. R. SKOPEK*tt, V. E. WALKER*, J. E. COCHRANEt, T. R. CRAFTt, AND N. F. CARIELLO* *Department of Pathology and tDepartment of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 Communicated by Kenneth M. Brinkhous, May 26, 1992 ABSTRACT We have determined the mutational spectrum quences for analysis. DGGE is based on the fact that the of N-ethyl-N-nitrosourea (ENU) in exon 3 of the hypoxanthine electrophoretic mobility of a DNA molecule in a polyacryl- guanine) phosphoribosyltransferase gene (Hprt) in splenic T amide gel is considerably reduced as the molecule becomes cells following in vivo exposure ofmale B6C3F1 mice (5-7 weeks partially melted (denatured). Mismatched heteroduplexes old) to ENU. Hpir mutants were isolated by culturing splenic formed by annealing wild-type and mutant DNA sequences T cells in microtiter dishes containing medium supplemented are always less stable than the corresponding perfectly base- with interleukin 2, concanavalin A, and 6-thiouanine. DNA paired homoduplexes and consequently melt at a lower was extracted from 6-thoa ne-sistant colonies and ampli- concentration of denaturant. Therefore, any mutant/wild- fied by the polymerase chain reaction (PCR) using primers type heteroduplex will always travel a shorter distance rel- flanking Hprt exon 3. Identification of mutant sequences and ative to wild-type homoduplexes in a gel containing a dient purification of mutant DNA from contaminating wild-type Hprt ofdenaturant.
    [Show full text]
  • Molecular Analysis of Hprt Gene Mutations in Skin Fibroblasts of Rats Exposed in Vivo to N-Methyl-N-Nitrosourea Or N-Ethyl-N-Nitrosourea'
    ICANCER RESEARCH54, 2478-2485, May 1, 19941 Molecular Analysis of hprt Gene Mutations in Skin Fibroblasts of Rats Exposed in Vivo to N-Methyl-N-nitrosourea or N-Ethyl-N-nitrosourea' Jacob G. Jansen,2 George it Mohn, Harry Vrieling, Come M. M. van Teijlingen, Paul H. M. Lohman, and Albert A. van Zeeland MGC-Department ofRadiation Genetics and Chemical Mutagenesis, State University ofLeiden, Wassenaarseweg 72, 2333 AL Leiden (J. G. J., H. V., C. M. M. v. T., P. H. M. L, A. A. v. Z.J; Laboratory of Carcinogenesis and Mutagenesis, National Institute of Public Health and Environmental Protection, Bilthoven [C. R. M.]; and J. A. Cohen Institute, Interuniversity Research Institute for Radiopathology and Radiation Protection, Leiden (H. V., A. A. v. Z.J, the Netherlands ABSTRACT apart from 06-guanine alkylation, MNU methylates preferentially the N-7 position of guanine and at a lower frequency the N-3 The granuloma pouch assay in the rat is a model system in which position of adenine, while ENU alkylates mostly phosphodiesters; relative frequencies of genetic and (pro-) neoplastic changes induced in vivo by carcinogenic agents can be determined within the same target and at lower frequencies the @2position of thymine and the N-7 tissue. The target is granuloma pouch tissue and consists of a population position of guanine. Ethylation by ENU at the N-3 position of of (transient) proliferating fibroblasts which can be cultured in vitro.hprt adenine, the 0― position of thymine, and the @2position of gene mutations were studied in granuloma pouch tissue of rats treated cytosine occurs at much lower frequencies.
    [Show full text]
  • Sequencing Chemically Induced Mutations in the Mutamouse Lacz
    bioRxiv preprint doi: https://doi.org/10.1101/858159; this version posted November 29, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 SEQUENCING CHEMICALLY INDUCED MUTATIONS IN THE MUTAMOUSE LACZ 2 REPORTER GENE IDENTIFIES HUMAN CANCER MUTATIONAL SIGNATURES 3 4 Marc A. Beal1,4*, Matt J. Meier2*, Danielle LeBlanc1, Clotilde Maurice1, Jason O’Brien3, Carole L. 5 Yauk1, Francesco Marchetti1,5 6 7 *These authors contributed equally to this work. 8 1Environmental Health Science and Research Bureau, Healthy Environments and Consumer 9 Safety Branch, Health Canada, Ottawa, Ontario, K1A 0K9, Canada. 10 2Science and Technology Branch, Environment and Climate Change Canada, Ottawa, Ontario, 11 K1A 0H3, Canada. 12 3National Wildlife Research Centre, Environment and Climate Change Canada, Ottawa, Ontario, 13 K1A 0H3, Canada. 14 4Present address: Existing Substances Risk Assessment Bureau, Health Canada, Ottawa, 15 Ontario, Canada 16 5Corresponding author: [email protected] 17 18 Other email addresses: [email protected], [email protected], 19 [email protected], [email protected], [email protected], 20 [email protected] 21 22 Running title: Induced lacZ mutations and human cancer signatures 1 bioRxiv preprint doi: https://doi.org/10.1101/858159; this version posted November 29, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
    [Show full text]
  • N-Nitroso-N-Ethylurea
    Right to Know Hazardous Substance Fact Sheet Common Name: N-NITROSO-N-ETHYLUREA Synonyms: ENU; N-Ethyl-N-Nitrosourea CAS Number: 759-73-9 Chemical Name: Urea, N-Ethyl-N-Nitroso- RTK Substance Number: 1410 Date: April 2002 Revision: October 2009 DOT Number: UN 3077 Description and Use EMERGENCY RESPONDERS >>>> SEE LAST PAGE N-Nitroso-N-Ethylurea is a light yellow powder or yellow-pink Hazard Summary crystal. It is used in tumor research and to make other Hazard Rating NJDOH NFPA chemicals. HEALTH 3 - FLAMMABILITY 1 - REACTIVITY 1 - CARCINOGEN TERATOGEN POISONOUS GASES ARE PRODUCED IN FIRE Reasons for Citation Hazard Rating Key: 0=minimal; 1=slight; 2=moderate; 3=serious; f N-Nitroso-N-Ethylurea is on the Right to Know Hazardous 4=severe Substance List because it is cited by DOT, NTP, DEP, IARC and EPA. f N-Nitroso-N-Ethylurea can affect you when inhaled. f This chemical is on the Special Health Hazard Substance f N-Nitroso-N-Ethylurea is a CARCINOGEN and MUTAGEN, List. and may be a TERATOGEN. HANDLE WITH EXTREME CAUTION. f Contact can irritate the skin and eyes. f Inhaling N-Nitroso-N-Ethylurea can irritate the nose and throat. f Exposure can cause headache, dizziness, and lightheadedness. SEE GLOSSARY ON PAGE 5. f N-Nitroso-N-Ethylurea may affect the liver and kidneys. FIRST AID Eye Contact Workplace Exposure Limits f Immediately flush with large amounts of water for at least 15 No occupational exposure limits have been established for minutes, lifting upper and lower lids. Remove contact N-Nitroso-N-Ethylurea.
    [Show full text]
  • N-Ethyl-N-Nitrosourea Induced Leukaemia in a Mouse Model Through Upregulation of Vascular Endothelial Growth Factor and Evading Apoptosis
    cancers Article N-Ethyl-n-Nitrosourea Induced Leukaemia in a Mouse Model through Upregulation of Vascular Endothelial Growth Factor and Evading Apoptosis Abdullahi Aliyu 1,2,* , Mohd Rosly Shaari 3, Nurul Syahirah Ahmad Sayuti 1, Mohd Farhan Hanif Reduan 1, Shanmugavelu Sithambaram 3, Mustapha Mohamed Noordin 1, Khozirah Shaari 4 and Hazilawati Hamzah 1,* 1 Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia UPM, Serdang 43400, Selangor, Malaysia; [email protected] (N.S.A.S.); [email protected] (M.F.H.R.); [email protected] (M.M.N.) 2 Department of Veterinary Pathology, Faculty of Veterinary Medicine, City Campus Complex, Usmanu Danfodiyo University, 840212 Sokoto, Sokoto State, Nigeria 3 Animal Science Research Centre, Malaysian Agricultural Research and Development Institute Headquarter, Serdang 43400, Selangor, Malaysia; [email protected] (M.R.S.); [email protected] (S.S.) 4 Department of Chemistry, Faculty of Science, Universiti Putra Malaysia UPM, Serdang 43400, Selangor, Malaysia; [email protected] * Correspondence: [email protected] (A.A.); [email protected] (H.H.) Received: 17 December 2019; Accepted: 4 February 2020; Published: 13 March 2020 Abstract: Chemical carcinogens are commonly used to investigate the biology and prognoses of various cancers. This study investigated the mechanism of leukaemogenic effects of n-ethyl- n-nitrosourea (ENU) in a mouse model. A total of 14 3-week-old male Institute of Cancer Research (ICR)-mice were used for the study. The mice were divided into groups A and B with seven mice each. Group A served as the control while group B received intraperitoneal (IP) injections of 80 mg/kg ENU twice with a one-week interval and were monitored monthly for 3 months for the development of leukaemia via blood smear examination.
    [Show full text]
  • Retention of Induced Mutations in a Drosophila Reverse-Genetic Resource
    Genetics: Published Articles Ahead of Print, published on September 9, 2008 as 10.1534/genetics.108.092437 Retention of induced mutations in a Drosophila reverse-genetic resource Jennifer L. Cooper*+, Elizabeth A. Greene*, Bradley J. Till*‡, Christine A. Codomo*, Barbara T. Wakimoto§ and Steven Henikoff*+ *Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA +Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA 98107, USA §Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA ‡Present address: FAO/IAEA Agricultural and Biotechnology Laboratory A-2444 Seibersdorf, Austria Running head: Retention of induced mutations Key words: mutagenesis, TILLING, balancer chromosomes, mutational spectrum, ethyl methanesulfonate Corresponding author: Steven Henikoff, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109-1024; Phone: (206) 667-4515; FAX (206) 667-5889; Email: [email protected] 2 ABSTRACT TILLING (Targeting Induced Local Lesions IN Genomes) is a reverse-genetic method to identify point mutations in chemically mutagenized populations. For functional genomics, it is ideal to have a stable collection of heavily mutagenized lines that can be screened over an extended period of time. However, long-term storage is impractical for Drosophila, so mutant strains must be maintained by continual propagation of live cultures. Here we evaluate a strategy in which ethylmethane sulfonate (EMS) mutagenized chromosomes were maintained as heterozygotes with balancer chromosomes for over 100 generations before screening. The strategy yielded a spectrum of point mutations similar to those found in previous studies of EMS-induced mutations, as well as 2.4% indels (insertions and deletions). Our analysis of 1887 point mutations in 148 targets showed evidence for selection against deleterious lesions and differential retention of lesions among targets based on their position relative to balancer breakpoints, leading to a broad distribution of mutational densities.
    [Show full text]
  • 1,3-Butadiene: Cancer, Mutations, and Adducts Part I: Carcinogenicity of 1,2,3,4-Diepoxybutane 955 Massachusetts Avenue Number 92 Cambridge MA 02139 USA Rogene F
    RESEARCH REPORT 1,3-Butadiene: Cancer, Mutations, and Adducts Part I: Carcinogenicity of 1,2,3,4-Diepoxybutane 955 Massachusetts Avenue Number 92 Cambridge MA 02139 USA Rogene F. Henderson et al March 2000 +1-617-876-6700 Part II: Roles of Two Metabolites of 1,3-Butadiene www.healtheffects.org in Mediating Its in Vivo Genotoxicity RESEARCH Leslie Recio et al REPORT Part III: In Vivo Mutation of the Endogenous hprt Genes of Mice and Rats by 1,3-Butadiene Number 92 March 2000 and Its Metabolites Vernon E. Walker and Quanxin Meng Part IV: Molecular Dosimetry of 1,3-Butadiene Ian A. Blair et al Part V: Hemoglobin Adducts as Biomarkers of 1,3-Butadiene Exposure and Metabolism James A. Swenberg et al Includes Commentaries by the Institute’s Health Review Committee BOARD OF DIRECTORS Archibald Cox Chair Alice Huang Carl M Loeb University Professor (Emeritus), Harvard Law School Senior Councilor for External Relations, California Institute of Technology Donald Kennedy Vice Chair Susan B King The Health Effects Institute, established HEALTH Editor-in-Chief, Science; President (Emeritus) and Bing Professor of Fellow, Sanford Institute of Public Policy, Duke University EFFECTS in 1980, is an independent and unbiased Biological Sciences, Stanford University Richard B Stewart INSTITUTE source of information on the health Douglas Costle Professor, New York University School of Law effects of motor vehicle emissions. HEI Chairman of the Board and Distinguished Senior Fellow, Institute Robert M White for Sustainable Communities President (Emeritus),
    [Show full text]
  • TASOR Is a Pseudo-PARP That Directs HUSH Complex Assembly and Epigenetic Transposon Control
    bioRxiv preprint doi: https://doi.org/10.1101/2020.03.09.974832; this version posted March 11, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. TASOR is a pseudo-PARP that directs HUSH complex assembly and epigenetic transposon control Christopher H. Douse1,‡, Iva A. Tchasovnikarova2,‡, Richard T. Timms2,‡, Anna V. Protasio2, Marta Seczynska2, Daniil M. Prigozhin1, Anna Albecka1,2, Jane Wagstaff3, James C. Williamson2, Stefan M.V. Freund3, Paul J. Lehner2*, Yorgo Modis1,2* 1 Molecular Immunity Unit, Department of Medicine, University of Cambridge, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK 2 Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Department of Medicine, University of Cambridge, Cambridge CB2 0AW, UK 3 Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK Current addresses: Department of Experimental Medical Science, Lund University, Sölvegatan 19, Lund, Sweden (C.H.D.); The Gurdon Institute, Tennis Court Road, Cambridge, UK (I.A.T.); Department of Pathology, Tennis Court Road, Cambridge, UK (A.V.P.); Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA (D.M.P.) ‡These authors contributed equally *co-corresponding authors Keywords: Transcriptional repression; epigenetic silencing; antiretroviral response; genome stability; histone H3 lysine 9 methylation (H3K9me3); transposable element (TE); long interspersed nuclear element-1 (LINE-1); poly-ADP ribose polymerase (PARP); RNA-binding protein; RNA-induced transcriptional silencing; CUT&RUN; CUT&Tag; genome profiling 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.03.09.974832; this version posted March 11, 2020.
    [Show full text]
  • Relevance of N-Nitroso Compounds to Human Cancer: Exposures and Mechanisms
    WORLD HEALTH ORGANIZATION ' Ю INTERNATIONAL AGENCY FOR RESEARCH ON CANCER RELEVANCE OF N-NITROSO COMPOUNDS TO HUMAN CANCER: EXPOSURES AND MECHANISMS Proceedings of the IXth International Symposium on N-Nitroso Compounds, held in Baden, Austria, 1-5 SeptemЬеr 1986 Co-sponsored by: National Cancer Institute (USA) Dr M. Okada Giapan) and associated Japanese industrial sponsors Thermedics Inc. (USA) Ciba-Geigy (Switzerland) Imperial Chemical Industries (UK) EDITORS H. BARTSCH, T.K. 0 NЕILL & R. SCHULTE-HERMANN JAR SCIENTIFIC PUBLICATIONS NO. 84 INTERNATIONAL AGENCY FOR RESEARCH ON CANCER LYON 1987 CONTENTS Foreword.................................................................. 1 Introduction................................................................ 3 Overview................................................................... 5 Keynote address P.N. Magee ............................................................. 11 1. MOLECULAR AND BIOCHEMICAL MECHANISMS Biochemical events in nitrosamine-induced hepatocarcinogenesis: relevance of animal data to human carcinogenesis R.Schulte-Hermann .....................................................17 Biochemical and molecular effects of N-nitroso compounds in human cultured cells: an overview C.C. Harris .............................................................20 Activation of the human c-Ha-ras-1 proto-oncogene by in-vitro reaction with N-nitroso- methyl(acetoxymethyl)amine S. Hirani-Hojatti, J.R. Milligan & M.C. Archer ..............................26 Specificity of OЬ-alkylguanine-DNA
    [Show full text]
  • Mutational Analysis of N-Ethyl-N-Nitrosourea (ENU) In
    bioRxiv preprint doi: https://doi.org/10.1101/486266; this version posted December 3, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. 1 Mutational analysis of N-ethyl-N-nitrosourea (ENU) in 2 the fission yeast Schizosaccharomyces pombe. 3 Rafael Hoyos-Manchado1, Juan Jiménez1* and Víctor A. Tallada1* 4 1Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/Consejo 5 Superior de Investigaciones Científicas, Carretera de Utrera Km1, 41013 Seville, Spain. 6 *Corresponding authors 7 E-mail: [email protected] 8 9 10 11 12 13 14 15 16 17 1 bioRxiv preprint doi: https://doi.org/10.1101/486266; this version posted December 3, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. 18 Abstract 19 Forward genetics has boosted our knowledge on genic function in a multitude of 20 biological models and it has significantly contributed to the understanding of genetic 21 bases of development, ageing and human diseases. With the advent of the next 22 generation sequencing and use of powerful bioinformatic tools, this traditional genetic 23 strategy has acquired a new impulse. At present, whole genome sequencing assisted by 24 in silico analysis allows the rapid and efficient identification of gene variants that are 25 responsible for a particular phenotype.
    [Show full text]
  • Ems) and N-Nitrose-N´-Ethyl Urea (Enu
    ORIGINAL PAPER EFFECT OF ETHYL METHANESULFONATE (EMS) AND N-NITROSE-N´-ETHYL UREA (ENU) ON CALLUS GROWTH OF COMMON BEAN ВЛИЯНИЕ НА ЕТИЛМЕТАН СУЛФОНАТА (EMС) И N-НИТРОЗО-N´-ETИЛ КАРБАМИДА (НEК) ВЪРХУ РАСТЕЖА НА КАЛУС ОТ ФАСУЛ Diana Lilova SVETLEVA1, Paola CRINÓ2 1Department of Genetics and Plant Breeding, Agricultural University, 4000 Plovdiv, Bulgaria 2ENEA C.R. Casaccia,UTS Biotecnologie, Protezione della Salute e degli Ecosistemi, 00060 Rome, Italy Manuscript received: October 14, 2005; Reviewed: February 16, 2005; Accepted for publication: March 12, 2005 ABSTRACT Infl uence of ethyl methanesulfonate (EMS) and N-nitrose-N´-ethyl urea (ENU) mutagenic treatments was investigated on three time sub-cultured calli obtained from leaf petiole explants of 7-day old sterile plants. Calibrated sterile seeds of the common bean Bulgarian variety Plovdiv 11M were pre-cultivated on MS basal medium supplemented with 1 µmM BAP. Then, both mutagens EMS and ENU were applied for different times such as 15, 30, 60 and 90 min on the explants at the concentrations of: 2.5 . 10-2 M and 6.2 . 10-3 M, respectively. Times of the mutagenic treatments infl uenced callus growth, calli from 30-min treatment with both mutagens showing the highest weights. In both cases, the 90-min mutagen application caused a too relevant effect either on callus browning or growth inhibition. In general, ENU showed a stronger effect than EMS. The effect of subcultures on callus growth was higher than mutagenic treatments. Interactions between these factors checked by by correlation ratio (η%) were quite low. KEY WORDS: Ethyl methanesulfonate (EMS), in vitro cultivation, mutagens, N-nitrose-N´-ethyl urea (ENU), Phaseolus vulgaris L.
    [Show full text]