Enamelin (Enam) is essential for amelogenesis: ENU-induced mouse mutants as models for different clinical subtypes of human amelogenesis imperfecta (AI).

Science.gov (United States)

Masuya, Hiroshi; Shimizu, Kunihiko; Sezutsu, Hideki; Sakuraba, Yoshiyuki; Nagano, Junko; Shimizu, Aya; Fujimoto, Naomi; Kawai, Akiko; Miura, Ikuo; Kaneda, Hideki; Kobayashi, Kimio; Ishijima, Junko; Maeda, Takahide; Gondo, Yoichi; Noda, Tetsuo; Wakana, Shigeharu; Shiroishi, Toshihiko

2005-03-01

Amelogenesis imperfecta (AI) is a group of commonly inherited defects of dental enamel formation, which exhibits marked genetic and clinical heterogeneity. The genetic basis of this heterogeneity is still poorly understood. Enamelin, the affected gene product in one form of AI (AIH2), is an extracellular matrix protein that is one of the components of enamel. We isolated three ENU-induced dominant mouse mutations, M100395, M100514 and M100521, which caused AI-like phenotypes in the incisors and molars of the affected individuals. Linkage analyses mapped each of the three mutations to a region of chromosome 5 that contained the genes encoding enamelin (Enam) and ameloblastin (Ambn). Sequence analysis revealed that each mutation was a single-base substitution in Enam. M100395 (Enam(Rgsc395)) and M100514 (Enam(Rgsc514)) were putative missense mutations that caused S to I and E to G substitutions at positions 55 and 57 of the translated protein, respectively. Enam(Rgsc395) and Enam(Rgsc514) heterozygotes showed severe breakage of the enamel surface, a phenotype that resembled local hypoplastic AI. The M100521 mutation (Enam(Rgsc521)) was a T to A substitution at the splicing donor site in intron 4. This mutation resulted in a frameshift that gave rise to a premature stop codon. The transcript of the Enam(Rgsc521) mutant allele was degraded, indicating that Enam(Rgsc521) is a loss-of-function mutation. Enam(Rgsc521) heterozygotes showed a hypomaturation-type AI phenotype in the incisors, possibly due to haploinsufficiency of Enam. Enam(Rgsc521) homozygotes showed complete loss of enamel on the incisors and the molars. Thus, we report here that the Enam gene is essential for amelogenesis, and that mice with different point mutations at Enam may provide good animal models to study the different clinical subtypes of AI.

The ENU-3 protein family members function in the Wnt pathway parallel to UNC-6/Netrin to promote motor neuron axon outgrowth in C. elegans.

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Florica, Roxana Oriana; Hipolito, Victoria; Bautista, Stephen; Anvari, Homa; Rapp, Chloe; El-Rass, Suzan; Asgharian, Alimohammad; Antonescu, Costin N; Killeen, Marie T

2017-10-01

The axons of the DA and DB classes of motor neurons fail to reach the dorsal cord in the absence of the guidance cue UNC-6/Netrin or its receptor UNC-5 in C. elegans. However, the axonal processes usually exit their cell bodies in the ventral cord in the absence of both molecules. Strains lacking functional versions of UNC-6 or UNC-5 have a low level of DA and DB motor neuron axon outgrowth defects. We found that mutations in the genes for all six of the ENU-3 proteins function to enhance the outgrowth defects of the DA and DB axons in strains lacking either UNC-6 or UNC-5. A mutation in the gene for the MIG-14/Wntless protein also enhances defects in a strain lacking either UNC-5 or UNC-6, suggesting that the ENU-3 and Wnt pathways function parallel to the Netrin pathway in directing motor neuron axon outgrowth. Our evidence suggests that the ENU-3 proteins are novel members of the Wnt pathway in nematodes. Five of the six members of the ENU-3 family are predicted to be single-pass trans-membrane proteins. The expression pattern of ENU-3.1 was consistent with plasma membrane localization. One family member, ENU-3.6, lacks the predicted signal peptide and the membrane-spanning domain. In HeLa cells ENU-3.6 had a cytoplasmic localization and caused actin dependent processes to appear. We conclude that the ENU-3 family proteins function in a pathway parallel to the UNC-6/Netrin pathway for motor neuron axon outgrowth, most likely in the Wnt pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

A novel ENU-mutation in ankyrin-1 disrupts malaria parasite maturation in red blood cells of mice.

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Andreas Greth

Full Text Available The blood stage of the plasmodium parasite life cycle is responsible for the clinical symptoms of malaria. Epidemiological studies have identified coincidental malarial endemicity and multiple red blood cell (RBC disorders. Many RBC disorders result from mutations in genes encoding cytoskeletal proteins and these are associated with increased protection against malarial infections. However the mechanisms underpinning these genetic, host responses remain obscure. We have performed an N-ethyl-N-nitrosourea (ENU mutagenesis screen and have identified a novel dominant (haploinsufficient mutation in the Ank-1 gene (Ank1(MRI23420 of mice displaying hereditary spherocytosis (HS. Female mice, heterozygous for the Ank-1 mutation showed increased survival to infection by Plasmodium chabaudi adami DS with a concomitant 30% decrease in parasitemia compared to wild-type, isogenic mice (wt. A comparative in vivo red cell invasion and parasite growth assay showed a RBC-autonomous effect characterised by decreased proportion of infected heterozygous RBCs. Within approximately 6-8 hours post-invasion, TUNEL staining of intraerythrocytic parasites, showed a significant increase in dead parasites in heterozygotes. This was especially notable at the ring and trophozoite stages in the blood of infected heterozygous mutant mice compared to wt (p<0.05. We conclude that increased malaria resistance due to ankyrin-1 deficiency is caused by the intraerythrocytic death of P. chabaudi parasites.

Spectra of molecular changes induced in DNA of Drosophila spermatozoa by 1-ethyl-1-nitrosourea and X-rays

International Nuclear Information System (INIS)

Batzer, M.A.; Fossett, N.G.; Lee, W.R.; Louisiana State Univ., Baton Rouge; Tedeschi, B.; Tucker, A.; Kilroy, G.; Arbour, P.

1988-01-01

Mutations induced in Drosophila spermatozoa at the alcohol dehydrogenase Adh locus by 1-ethyl-1-nitrosourea (ENU) were compared to X-ray-induced mutations using genetic tests for complementation, southern blotting, western blotting and northern blotting. 8 of 10 ENU-induced mutations complemented all known adjacent loci and were presumed to be intragenic. In contrast, 8 of 30 X-ray-induced mutations were intragenic. The interpretation of these results is that in spermatozoa X-rays induce primarily deletions that either produce deficiencies of the Adh locus or nonsense mutations within the locus, whereas ENU induces primarily missense mutations. This forward mutation assay based on loss of enzymatic activity efficiently recovered a broad spectrum of mutations ranging from missense to intragenic deletions and multi-locus deficiencies. Only 3 of these 40 mutations produced a polypeptide detectable as an electrophoretic variant. 37 refs.; 6 figs.; 2 tabs

A mouse model of hereditary coproporphyria identified in an ENU mutagenesis screen

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Ashlee J. Conway

2017-08-01

Full Text Available A genome-wide ethyl-N-nitrosourea (ENU mutagenesis screen in mice was performed to identify novel regulators of erythropoiesis. Here, we describe a mouse line, RBC16, which harbours a dominantly inherited mutation in the Cpox gene, responsible for production of the haem biosynthesis enzyme, coproporphyrinogen III oxidase (CPOX. A premature stop codon in place of a tryptophan at amino acid 373 results in reduced mRNA expression and diminished protein levels, yielding a microcytic red blood cell phenotype in heterozygous mice. Urinary and faecal porphyrins in female RBC16 heterozygotes were significantly elevated compared with that of wild-type littermates, particularly coproporphyrinogen III, whereas males were biochemically normal. Attempts to induce acute porphyric crises were made using fasting and phenobarbital treatment on females. While fasting had no biochemical effect on RBC16 mice, phenobarbital caused significant elevation of faecal coproporphyrinogen III in heterozygous mice. This is the first known investigation of a mutagenesis mouse model with genetic and biochemical parallels to hereditary coproporphyria.

ENU mutagenesis screening for dominant behavioral mutations based on normal control data obtained in home-cage activity, open-field, and passive avoidance tests.

Science.gov (United States)

Wada, Yumiko; Furuse, Tamio; Yamada, Ikuko; Masuya, Hiroshi; Kushida, Tomoko; Shibukawa, Yoko; Nakai, Yuji; Kobayashi, Kimio; Kaneda, Hideki; Gondo, Yoichi; Noda, Tetsuo; Shiroishi, Toshihiko; Wakana, Shigeharu

2010-01-01

To establish the cutoff values for screening ENU-induced behavioral mutations, normal variations in mouse behavioral data were examined in home-cage activity (HA), open-field (OF), and passive-avoidance (PA) tests. We defined the normal range as one that included more than 95% of the normal control values. The cutoffs were defined to identify outliers yielding values that deviated from the normal by less than 5% for C57BL/6J, DBA/2J, DBF(1), and N(2) (DXDB) progenies. Cutoff values for G1-phenodeviant (DBF(1)) identification were defined based on values over +/- 3.0 SD from the mean of DBF(1) for all parameters assessed in the HA and OF tests. For the PA test, the cutoff values were defined based on whether the mice met the learning criterion during the 2nd (at a shock intensity of 0.3 mA) or the 3rd (at a shock intensity of 0.15 mA) retention test. For several parameters, the lower outliers were undetectable as the calculated cutoffs were negative values. Based on the cutoff criteria, we identified 275 behavioral phenodeviants among 2,646 G1 progeny. Of these, 64 were crossed with wild-type DBA/2J individuals, and the phenotype transmission was examined in the G2 progeny using the cutoffs defined for N(2) mice. In the G2 mice, we identified 15 novel dominant mutants exhibiting behavioral abnormalities, including hyperactivity in the HA or OF tests, hypoactivity in the OF test, and PA deficits. Genetic and detailed behavioral analysis of these ENU-induced mutants will provide novel insights into the molecular mechanisms underlying behavior.

Nature of mutants induced by ionizing radiation in cultured hamster cells. II. Antigenic response and reverse mutation of HPRT-deficient mutants induced by. gamma. -rays or ethyl methanesulphonate

Energy Technology Data Exchange (ETDEWEB)

Brown, R; Stretch, A; Thacker, J

1986-04-01

A large series of independent mutants deficient in HPRT enzyme activity, isolated from V79-4 hamster cells, were assessed for properties which reflect the nature of the genetic changes induced. A total of 88 mutants were screened, 43 isolated from ..gamma..-ray-treated cultures and 45 induced by ethyl methanesulphonate (EMS). Firstly, each mutant was assayed for the presence of protein with the antigenic response of HPRT. In a competitive inhibition assay, 31% of EMS-induced mutants were CRM-positive compared to 7% of the ..gamma..-ray series. Secondly, each mutant was tested for ability to revert to HPRT proficiency. All except 2 of the EMS-induced mutants reverted with ethyl nitrosourea ENU, and many reverted spontaneously, under the given conditions. However reversion was not detected in about 80% of ..gamma..-ray-induced mutants, suggesting that the types of forward mutation caused by ionizing radiation differ qualitatively from those caused by EMS. (Auth.). 30 refs.; 6 figs.; 2 tabs.

Mouse ENU Mutagenesis to Understand Immunity to Infection: Methods, Selected Examples, and Perspectives

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Grégory Caignard

2014-09-01

Full Text Available Infectious diseases are responsible for over 25% of deaths globally, but many more individuals are exposed to deadly pathogens. The outcome of infection results from a set of diverse factors including pathogen virulence factors, the environment, and the genetic make-up of the host. The completion of the human reference genome sequence in 2004 along with technological advances have tremendously accelerated and renovated the tools to study the genetic etiology of infectious diseases in humans and its best characterized mammalian model, the mouse. Advancements in mouse genomic resources have accelerated genome-wide functional approaches, such as gene-driven and phenotype-driven mutagenesis, bringing to the fore the use of mouse models that reproduce accurately many aspects of the pathogenesis of human infectious diseases. Treatment with the mutagen N-ethyl-N-nitrosourea (ENU has become the most popular phenotype-driven approach. Our team and others have employed mouse ENU mutagenesis to identify host genes that directly impact susceptibility to pathogens of global significance. In this review, we first describe the strategies and tools used in mouse genetics to understand immunity to infection with special emphasis on chemical mutagenesis of the mouse germ-line together with current strategies to efficiently identify functional mutations using next generation sequencing. Then, we highlight illustrative examples of genes, proteins, and cellular signatures that have been revealed by ENU screens and have been shown to be involved in susceptibility or resistance to infectious diseases caused by parasites, bacteria, and viruses.

Comprehensive behavioral analysis of ENU-induced Disc1-Q31L and -L100P mutant mice

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Shoji Hirotaka

2012-02-01

Full Text Available Abstract Background Disrupted-in-Schizophrenia 1 (DISC1 is considered to be a candidate susceptibility gene for psychiatric disorders, including schizophrenia, bipolar disorder, and major depression. A recent study reported that N-ethyl-N-nitrosourea (ENU-induced mutations in exon 2 of the mouse Disc1 gene, which resulted in the amino acid exchange of Q31L and L100P, caused an increase in depression-like behavior in 31 L mutant mice and schizophrenia-like behavior in 100P mutant mice; thus, these are potential animal models of psychiatric disorders. However, remaining heterozygous mutations that possibly occur in flanking genes other than Disc1 itself might induce behavioral abnormalities in the mutant mice. Here, to confirm the effects of Disc1-Q31L and Disc1-L100P mutations on behavioral phenotypes and to investigate the behaviors of the mutant mice in more detail, the mutant lines were backcrossed to C57BL/6JJcl through an additional two generations and the behaviors were analyzed using a comprehensive behavioral test battery. Results Contrary to expectations, 31 L mutant mice showed no significant behavioral differences when compared with wild-type control mice in any of the behavioral tests, including the Porsolt forced swim and tail suspension tests, commonly used tests for depression-like behavior. Also, 100P mutant mice exhibited no differences in almost all of the behavioral tests, including the prepulse inhibition test for measuring sensorimotor gating, which is known to be impaired in schizophrenia patients; however, 100P mutant mice showed higher locomotor activity compared with wild-type control mice in the light/dark transition test. Conclusions Although these results are partially consistent with the previous study in that there was hyperactivity in 100P mutant mice, the vast majority of the results are inconsistent with those of the previous study; this discrepancy may be explained by differences in the genetic background of the

Phenotype screening for genetically deermined age-onset disorders and increased longevity in ENU-mutagenized mice

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Johnson, Dabney K [ORNL; Rinchik, Eugene M [ORNL; Moustaid-Moussa, Naima [University of Tennessee, Knoxville (UTK); Miller, Darla R [ORNL; Williams, Robert [University of Tennessee Health Science Center, Memphis; Michaud III, Edward J [ORNL; Jablonski, Monica M. [University of Tennessee Health Science Center, Memphis; Elberger, Andrea [University of Tennessee Health Science Center, Memphis; Hamre, Kristin M. [University of Tennessee Health Science Center, Memphis; Smeyne, Richard [St. Jude Children' s Research Hospital; Chesler, Elissa J [ORNL; Goldowitz, Daniel [University of Tennessee Health Science Center, Memphis

2005-01-01

With the goal of discovering genes that contribute to late-onset neurological and ocular disorders and also genes that extend the healthy life span in mammals, we are phenotyping mice carrying new mutations induced by the chemical N-ethyl-N-nitrosourea (ENU). The phenotyping plan includes basic behavioral, neurohistological, and vision testing in sibling cohorts of mice aged to 18 months, and then evaluation for markers of growth trajectory and stress response in these same cohorts aged up to 28 months. Statistical outliers are identified by comparison to test results of similar aged cohorts, and potential mutants are recovered for re-aging to confirm heritability of the phenotype.

Novel allelic mutations in murine Serca2 induce differential development of squamous cell tumors

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Toki, Hideaki; Minowa, Osamu; Inoue, Maki; Motegi, Hiromi; Karashima, Yuko; Ikeda, Ami [Team for Advanced Development and Evaluation of Human Disease Models, Riken BioResource Center (BRC), Tsukuba, Ibaraki (Japan); Kaneda, Hideki [Technology and Development Team for Mouse Phenotype Analysis, Riken BRC, Tsukuba, Ibaraki (Japan); Sakuraba, Yoshiyuki [Mutagenesis and Genomics Team, Riken BRC, Tsukuba, Ibaraki (Japan); Saiki, Yuriko [Department of Molecular Pathology, Tohoku University Graduate School of Medicine, Sendai, Miyagi (Japan); Wakana, Shigeharu [Technology and Development Team for Mouse Phenotype Analysis, Riken BRC, Tsukuba, Ibaraki (Japan); Suzuki, Hiroshi [Department of Biochemistry, Asahikawa Medical University, Asahikawa, Hokkaido (Japan); Gondo, Yoichi [Mutagenesis and Genomics Team, Riken BRC, Tsukuba, Ibaraki (Japan); Shiroishi, Toshihiko [Mammalian Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka (Japan); Noda, Tetsuo, E-mail: tnoda@jfcr.or.jp [Team for Advanced Development and Evaluation of Human Disease Models, Riken BioResource Center (BRC), Tsukuba, Ibaraki (Japan); Department of Cell Biology, Cancer Institute, The Japanese Foundation for Cancer Research, Tokyo (Japan)

2016-08-05

Dominant mutations in the Serca2 gene, which encodes sarco(endo)plasmic reticulum calcium-ATPase, predispose mice to gastrointestinal epithelial carcinoma [1–4] and humans to Darier disease (DD) [14–17]. In this study, we generated mice harboring N-ethyl-N-nitrosourea (ENU)-induced allelic mutations in Serca2: three missense mutations and one nonsense mutation. Mice harboring these Serca2 mutations developed tumors that were categorized as either early onset squamous cell tumors (SCT), with development similar to null-type knockout mice [2,4] (aggressive form; M682, M814), or late onset tumors (mild form; M1049, M1162). Molecular analysis showed no aberration in Serca2 mRNA or protein expression levels in normal esophageal cells of any of the four mutant heterozygotes. There was no loss of heterozygosity at the Serca2 locus in the squamous cell carcinomas in any of the four lines. The effect of each mutation on Ca{sup 2+}-ATPase activity was predicted using atomic-structure models and accumulated mutated protein studies, suggesting that putative complete loss of Serca2 enzymatic activity may lead to early tumor onset, whereas mutations in which Serca2 retains residual enzymatic activity result in late onset. We propose that impaired Serca2 gene product activity has a long-term effect on squamous cell carcinogenesis from onset to the final carcinoma stage through an as-yet unrecognized but common regulatory pathway. -- Highlights: •Novel mutations in murine Serca2 caused early onset or late onset of tumorigenesis. •They also caused higher or lower incidence of Darier Disease phenotype. •3D structure model suggested the former mutations led to severer defect on ATPase. •Driver gene mutations via long-range effect on Ca2+ distributions are suggested.

Combined exposure to X-irradiation followed by N-ethyl-N-nitrosourea treatment alters the frequency and spectrum of Ikaros point mutations in murine T-cell lymphoma

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Kakinuma, Shizuko, E-mail: skakinum@nirs.go.jp [Radiobiology for Children' s Health Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Nishimura, Mayumi; Amasaki, Yoshiko; Takada, Mayumi; Yamauchi, Kazumi; Sudo, Satomi; Shang, Yi [Radiobiology for Children' s Health Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Doi, Kazutaka; Yoshinaga, Shinji [Regulatory Sciences Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shimada, Yoshiya [Radiobiology for Children' s Health Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

2012-09-01

Ionizing radiation is a well-known carcinogen, but its potency may be influenced by other environmental carcinogens, which is of practical importance in the assessment of risk. Data are scarce, however, on the combined effect of radiation with other environmental carcinogens and the underlying mechanisms involved. We studied the mode and mechanism of the carcinogenic effect of radiation in combination with N-ethyl-N-nitrosourea (ENU) using doses approximately equal to the corresponding thresholds. B6C3F1 mice exposed to fractionated X-irradiation (Kaplan's method) followed by ENU developed T-cell lymphomas in a dose-dependent manner. Radiation doses above an apparent threshold acted synergistically with ENU to promote lymphoma development, whereas radiation doses below that threshold antagonized lymphoma development. Ikaros, which regulates the commitment and differentiation of lymphoid lineage cells, is a critical tumor suppressor gene frequently altered in both human and mouse lymphomas and shows distinct mutation spectra between X-ray- and ENU-induced lymphomas. In the synergistically induced lymphomas, we observed a low frequency of LOH and an inordinate increase of Ikaros base substitutions characteristic of ENU-indcued point mutations, G:C to A:T at non-CpG, A:T to G:C, G:C to T:A and A:T to T:A. This suggests that radiation doses above an apparent threshold activate the ENU mutagenic pathway. This is the first report on the carcinogenic mechanism elicited by combined exposure to carcinogens below and above threshold doses based on the mutation spectrum of the causative gene. These findings constitute a basis for assessing human cancer risk following exposure to multiple carcinogens.

Chromoanasynthetic Genomic Rearrangement Identified in a N-Ethyl-N-Nitrosourea (ENU Mutagenesis Screen in Caenorhabditis elegans

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Omar A. Itani

2016-02-01

Full Text Available Chromoanasynthesis is a recently discovered phenomenon in humans with congenital diseases that is characterized by complex genomic rearrangements (CGRs resulting from aberrant repair of catastrophic chromosomal damage. How these CGRs are induced is not known. Here, we describe the structure and function of dpDp667, a causative CGR that emerged from a Caenorhabditis elegans dauer suppressor screen in which animals were treated with the point mutagen N-ethyl-N-nitrosourea (ENU. dpDp667 comprises nearly 3 Mb of sequence on the right arm of the X chromosome, contains three duplications and one triplication, and is devoid of deletions. Sequences from three out of the four breakpoint junctions in dpDp667 reveal microhomologies that are hallmarks of chromoanasynthetic CGRs. Our findings suggest that environmental insults and physiological processes that cause point mutations may give rise to chromoanasynthetic rearrangements associated with congenital disease. The relatively subtle phenotype of animals harboring dpDp667 suggests that the prevalence of CGRs in the genomes of mutant and/or phenotypically unremarkable animals may be grossly underestimated.

CD48-deficient T-lymphocytes from DMBA-treated rats have de novo mutations in the endogenous Pig-a gene.

Science.gov (United States)

Dobrovolsky, Vasily N; Revollo, Javier; Pearce, Mason G; Pacheco-Martinez, M Monserrat; Lin, Haixia

2015-10-01

A major question concerning the scientific and regulatory acceptance of the rodent red blood cell-based Pig-a gene mutation assay is the extent to which mutants identified by their phenotype in the assay are caused by mutations in the Pig-a gene. In this study, we identified T-lymphocytes deficient for the glycosylphosphatidylinositol-anchored surface marker, CD48, in control and 7,12-dimethylbenz[a]anthracene (DMBA)-treated rats using a flow cytometric assay and determined the spectra of mutations in the endogenous Pig-a gene in these cells. CD48-deficient T-cells were seeded by sorting at one cell per well into 96-well plates, expanded into clones, and exons of their genomic Pig-a were sequenced. The majority (78%) of CD48-deficient T-cell clones from DMBA-treated rats had mutations in the Pig-a gene. The spectrum of DMBA-induced Pig-a mutations was dominated by mutations at A:T, with the mutated A being on the nontranscribed strand and A → T transversion being the most frequent change. The spectrum of Pig-a mutations in DMBA-treated rats was different from the spectrum of Pig-a mutations in N-ethyl-N-nitrosourea (ENU)-treated rats, but similar to the spectrum of DMBA mutations for another endogenous X-linked gene, Hprt. Only 15% of CD48-deficient mutants from control animals contained Pig-a mutations; T-cell biology may be responsible for a relatively large fraction of false Pig-a mutant lymphocytes in control animals. Among the verified mutants from control rats, the most common were frameshifts and deletions. The differences in the spectra of spontaneous, DMBA-, and ENU-induced Pig-a mutations suggest that the flow cytometric Pig-a assay detects de novo mutation in the endogenous Pig-a gene. © 2015 Wiley Periodicals, Inc.

Workshop on ENU Mutagenesis: Planning for Saturation, July 25-28, 2002

Energy Technology Data Exchange (ETDEWEB)

Nadeau, Joseph H

2002-07-25

The goal of the conference is to enhance the development of improved technologies and new approaches to the identification of genes underlying chemically-induced mutant phenotypes. The conference brings together ENU mutagenesis experts from the United States and aborad for a small, intensive workshop to consider these issues.

Combined effects of ionizing radiation and N-ethyl-N-nitrosourea in murine T-cell lymphoma-genesis

International Nuclear Information System (INIS)

Shizuko, Kakinuma; Yoshiko, Amasaki; Kazumi, Yamauchi; Mayumi, Nishimura; Tatsuhiko, Imaoka; Yoshiya, Shimada

2006-01-01

We are living in the environment with numerous natural and man-made radiation and chemicals. Cancer development in human is considered as a result of interaction with these factors. But, the quantitative assessment and mechanistic understanding of combined effects of radiation and chemical carcinogens are still insufficient. The aim of this study is to elucidate the mode and mechanism of the combined effect of X-rays with N-ethyl-N-nitrosourea (ENU) on mouse T-cell leukemogenesis, especially at low or threshold dose range. We previously showed that the dose-response curve for X-ray- or ENU induced thymic lymphoma (TL) had threshold dose. X-ray-induced TL was characteristic for frequent inactivation of Ikaros caused by transcriptional silencing, unusual splicing, point mutation and small insertion, most of which were associated with loss of heterozygosity (LOH). In contrast, ENU-induced tumors had point mutations of Ikaros without LOH. In combination, X-irradiation followed by ENU exposure resulted in the synergistic effect at high dose, while the effect was antagonistic at low or threshold dose. When the order of exposure was reversed, i.e., ENU followed by X-rays, the mode of combined exposure was additive at any doses. Molecular analysis demonstrated that Ikaros mutation in TL after X-irradiation followed by ENLI at high doses was predominantly point mutation without LOH (ENU-type). But, after reverse treatment, mutation spectrum of Ikaros was similar to that observed in TL after X-ray exposure alone. It is concluded that the mode of combined effect is dependent upon the treatment order and the dose of carcinogens. (author)

Modifier action of the chlorophyllin of the mutagenesis induced by the ethyl-nitroso-urea (ENU) in germinal cells of Drosophila melanogaster

International Nuclear Information System (INIS)

Morales N, I.

2006-01-01

The cupro-sodium chlorophyllin (CCS) it is a soluble porphyrin in water that it includes in its it structures a copper atom instead of the magnesium that has the chlorophyll. Diverse experiments have demonstrated that it possesses a potent activity, reducing or inhibiting, the DNA damage caused by physical and chemical agents of direct action or insinuation. Most of the knowledge about their anti genotoxic activity has been obtained using somatic cells of different organisms, on the other hand it is known very little of their effect in germinal cells. At the moment in the Drosophila laboratory of the ININ it is investigating the protective action of the CCS in germinal cells, with these studies has been observed that its administration to females that were crossed with males irradiated with 20 Gy of gamma radiation, promotes the induction of lethal dominant in the embryonic and post-embryonic states causing a diminution in the viability egg-adult. With the test of lethal recessive bound to the sex one has evidence that it increases the basal frequency of lethal recessive and it doesn't reduce those induced by radiation. In contrast, with the present investigation when the CCS was administered to males that later on were treated with ethyl-nitroso-urea (ENU) caused a reduction of the lethal frequency in all the monitored cellular states, but only it was significant in the post-meiotic cells. On the contrary, when the CCS was administered to the female ones and then they crossed with males treaties with ENU, it was observed a tendency to increase the lethal ones in all the cellular types. With both protocols the CCS caused a diminution of the sterility. The fact that the CCS has antagonistic activities, it deserves special attention to investigate with different protocols and systems, the conditions in that this pigment can work as a true antimutagenic and/or anti carcinogenic before being able to him to propose as a chemopreventor. (Author)

ENU mutagenesis to generate genetically modified rat models.

Science.gov (United States)

van Boxtel, Ruben; Gould, Michael N; Cuppen, Edwin; Smits, Bart M G

2010-01-01

The rat is one of the most preferred model organisms in biomedical research and has been extremely useful for linking physiology and pathology to the genome. However, approaches to genetically modify specific genes in the rat germ line remain relatively scarce. To date, the most efficient approach for generating genetically modified rats has been the target-selected N-ethyl-N-nitrosourea (ENU) mutagenesis-based technology. Here, we describe the detailed protocols for ENU mutagenesis and mutant retrieval in the rat model organism.

Modifier action of the chlorophyllin of the mutagenesis induced by the ethyl-nitroso-urea (ENU) in germinal cells of Drosophila melanogaster; Accion modificadora de la clorofilina de la mutagenesis inducida por la etil-nitroso-urea (ENU) en celulas germinales de Drosophila melanogaster

Energy Technology Data Exchange (ETDEWEB)

Morales N, I

2006-07-01

The cupro-sodium chlorophyllin (CCS) it is a soluble porphyrin in water that it includes in its it structures a copper atom instead of the magnesium that has the chlorophyll. Diverse experiments have demonstrated that it possesses a potent activity, reducing or inhibiting, the DNA damage caused by physical and chemical agents of direct action or insinuation. Most of the knowledge about their anti genotoxic activity has been obtained using somatic cells of different organisms, on the other hand it is known very little of their effect in germinal cells. At the moment in the Drosophila laboratory of the ININ it is investigating the protective action of the CCS in germinal cells, with these studies has been observed that its administration to females that were crossed with males irradiated with 20 Gy of gamma radiation, promotes the induction of lethal dominant in the embryonic and post-embryonic states causing a diminution in the viability egg-adult. With the test of lethal recessive bound to the sex one has evidence that it increases the basal frequency of lethal recessive and it doesn't reduce those induced by radiation. In contrast, with the present investigation when the CCS was administered to males that later on were treated with ethyl-nitroso-urea (ENU) caused a reduction of the lethal frequency in all the monitored cellular states, but only it was significant in the post-meiotic cells. On the contrary, when the CCS was administered to the female ones and then they crossed with males treaties with ENU, it was observed a tendency to increase the lethal ones in all the cellular types. With both protocols the CCS caused a diminution of the sterility. The fact that the CCS has antagonistic activities, it deserves special attention to investigate with different protocols and systems, the conditions in that this pigment can work as a true antimutagenic and/or anti carcinogenic before being able to him to propose as a chemopreventor. (Author)

Gamma-ray-induced dominant mutations that cause skeletal abnormalities in mice

International Nuclear Information System (INIS)

Selby, P.B.; Selby, P.R.

1977-01-01

Male mice were exposed to 100 R + 500 R γ-rays (60 R/min) with a 24-h fractionation interval. Skeletons of F 1 sons were examined for abnormalities, and, if any were found, the skeletons of their descendants were also examined. Of 2646 sons from treated spermatogonia, 37, or 1.4%, were diagnosed as carriers of autosomal dominant mutations affecting the skeleton, 31 by breeding tests, and six by other criteria for identifying mutations in F 1 's having no progeny. Many mutations caused a large number of anomalies in different regions of the skeleton. Most regions of the skeleton were affected by at least one mutation, and the mutations had incomplete penetrance for some or all of their effects. Three of the mutations affected skeletal size only. If certain assumptions are made, these skeletal data can be used to derive an estimate of induced genetic damage from dominant mutations affecting all parts of the body. When applied to man, the resultant risk estimate is not inconsistent with that made for dominant and irregularly inherited diseases by the BEIR Committee, by use of the doubling-dose method. Since most of the mutations can be characterized as models of irregularly inherited conditions in man, the data directly relate to the controversy over the relative importance of mutation pressure and balanced selection in maintaining man's large burden of irregularly inherited disease. Contrary to a recent hypothesis by H.B. Newcombe that man's large burden of irregularly inherited disease is maintained almost exclusively by balanced selection, these results suggest that at least an important fraction of the irregularly inherited conditions are maintained by mutation pressure. Therefore, this finding does not support the major changes in the estimate of genetic hazard to man that would be required on the basis of Newcombe's hypothesis

Investigating the effects of dietary folic acid on sperm count, DNA damage and mutation in Balb/c mice

International Nuclear Information System (INIS)

Swayne, Breanne G.; Kawata, Alice; Behan, Nathalie A.; Williams, Andrew; Wade, Mike G.; MacFarlane, Amanda J.; Yauk, Carole L.

2012-01-01

To date, fewer than 50 mutagens have been studied for their ability to cause heritable mutations. The majority of those studied are classical mutagens like radiation and anti-cancer drugs. Very little is known about the dietary variables influencing germline mutation rates. Folate is essential for DNA synthesis and methylation and can impact chromatin structure. We therefore determined the effects of folic acid-deficient (0 mg/kg), control (2 mg/kg) and supplemented (6 mg/kg) diets in early development and during lactation or post-weaning on mutation rates and chromatin quality in sperm of adult male Balb/c mice. The sperm chromatin structure assay and mutation frequencies at expanded simple tandem repeats (ESTRs) were used to evaluate germline DNA integrity. Treatment of a subset of mice fed the control diet with the mutagen ethylnitrosourea (ENU) at 8 weeks of age was included as a positive control. ENU treated mice exhibited decreased cauda sperm counts, increased DNA fragmentation and increased ESTR mutation frequencies relative to non-ENU treated mice fed the control diet. Male mice weaned to the folic acid deficient diet had decreased cauda sperm numbers, increased DNA fragmentation index, and increased ESTR mutation frequency. Folic acid deficiency in early development did not lead to changes in sperm counts or chromatin integrity in adult mice. Folic acid supplementation in early development or post-weaning did not affect germ cell measures. Therefore, adequate folic acid intake in adulthood is important for preventing chromatin damage and mutation in the male germline. Folic acid supplementation at the level achieved in this study does not improve nor is it detrimental to male germline chromatin integrity.

Investigating the effects of dietary folic acid on sperm count, DNA damage and mutation in Balb/c mice

Energy Technology Data Exchange (ETDEWEB)

Swayne, Breanne G.; Kawata, Alice [Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, K1A 0K9 (Canada); Behan, Nathalie A. [Nutrition Research Division, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, K1A 0K9 (Canada); Williams, Andrew; Wade, Mike G. [Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, K1A 0K9 (Canada); MacFarlane, Amanda J. [Nutrition Research Division, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, K1A 0K9 (Canada); Yauk, Carole L., E-mail: carole.yauk@hc-sc.ga.ca [Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, K1A 0K9 (Canada)

2012-09-01

To date, fewer than 50 mutagens have been studied for their ability to cause heritable mutations. The majority of those studied are classical mutagens like radiation and anti-cancer drugs. Very little is known about the dietary variables influencing germline mutation rates. Folate is essential for DNA synthesis and methylation and can impact chromatin structure. We therefore determined the effects of folic acid-deficient (0 mg/kg), control (2 mg/kg) and supplemented (6 mg/kg) diets in early development and during lactation or post-weaning on mutation rates and chromatin quality in sperm of adult male Balb/c mice. The sperm chromatin structure assay and mutation frequencies at expanded simple tandem repeats (ESTRs) were used to evaluate germline DNA integrity. Treatment of a subset of mice fed the control diet with the mutagen ethylnitrosourea (ENU) at 8 weeks of age was included as a positive control. ENU treated mice exhibited decreased cauda sperm counts, increased DNA fragmentation and increased ESTR mutation frequencies relative to non-ENU treated mice fed the control diet. Male mice weaned to the folic acid deficient diet had decreased cauda sperm numbers, increased DNA fragmentation index, and increased ESTR mutation frequency. Folic acid deficiency in early development did not lead to changes in sperm counts or chromatin integrity in adult mice. Folic acid supplementation in early development or post-weaning did not affect germ cell measures. Therefore, adequate folic acid intake in adulthood is important for preventing chromatin damage and mutation in the male germline. Folic acid supplementation at the level achieved in this study does not improve nor is it detrimental to male germline chromatin integrity.

Creation of miniature pig model of human Waardenburg syndrome type 2A by ENU mutagenesis.

Science.gov (United States)

Hai, Tang; Guo, Weiwei; Yao, Jing; Cao, Chunwei; Luo, Ailing; Qi, Meng; Wang, Xianlong; Wang, Xiao; Huang, Jiaojiao; Zhang, Ying; Zhang, Hongyong; Wang, Dayu; Shang, Haitao; Hong, Qianlong; Zhang, Rui; Jia, Qitao; Zheng, Qiantao; Qin, Guosong; Li, Yongshun; Zhang, Tao; Jin, Weiwu; Chen, Zheng-Yi; Wang, Hongmei; Zhou, Qi; Meng, Anming; Wei, Hong; Yang, Shiming; Zhao, Jianguo

2017-11-01

Human Waardenburg syndrome 2A (WS2A) is a dominant hearing loss (HL) syndrome caused by mutations in the microphthalmia-associated transcription factor (MITF) gene. In mouse models with MITF mutations, WS2A is transmitted in a recessive pattern, which limits the study of hearing loss (HL) pathology. In the current study, we performed ENU (ethylnitrosourea) mutagenesis that resulted in substituting a conserved lysine with a serine (p. L247S) in the DNA-binding domain of the MITF gene to generate a novel miniature pig model of WS2A. The heterozygous mutant pig (MITF +/L247S ) exhibits a dominant form of profound HL and hypopigmentation in skin, hair, and iris, accompanied by degeneration of stria vascularis (SV), fused hair cells, and the absence of endocochlear potential, which indicate the pathology of human WS2A. Besides hypopigmentation and bilateral HL, the homozygous mutant pig (MITF L247S/L247S ) and CRISPR/Cas9-mediated MITF bi-allelic knockout pigs both exhibited anophthalmia. Three WS2 patients carrying MITF mutations adjacent to the corresponding region were also identified. The pig models resemble the clinical symptom and molecular pathology of human WS2A patients perfectly, which will provide new clues for better understanding the etiology and development of novel treatment strategies for human HL.

Instability of expanded simple tandem repeats is induced in cell culture by a variety of agents: N-Nitroso-N-ethylurea, benzo(a)pyrene, etoposide and okadaic acid

Energy Technology Data Exchange (ETDEWEB)

Polyzos, Aris [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada); Parfett, Craig [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada); Healy, Caroline [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada); Douglas, George R. [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada); Yauk, Carole L. [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada)]. E-mail: Carole_Yauk@hc-sc.gc.ca

2006-06-25

Expanded simple tandem repeat (ESTR) sequences have proven useful biomarkers to detect genotoxicity in vivo. Their high sensitivity has been used to assess environmentally relevant doses of mutagens such as ionizing radiation, DNA alkylating agents and airborne particulate pollution, for germline mutations in mouse assays. The mutagenic response involves size alteration of these ESTR loci induced by agents causing a variety of cellular damage. The mechanistic aspects of this induced instability remain unclear and have not been studied in detail. Mechanistic knowledge is important to help understand the relevance of increased ESTR mutation frequencies. In this study, we applied a murine cell culture system to examine induced response to four agents exhibiting different modes of toxic action including: N-nitroso-N-ethylurea (ENU), benzo(a)pyrene (BaP), okadaic acid and etoposide at slightly sub-toxic levels. We used single-molecule-polymerase chain reaction (SM-PCR) to assess the relative mutant frequency after 4-week chemical treatments at the Ms6-hm ESTR sequence of cultured C3H/10T1/2 cells (a mouse embryonic cell line). Increased mutation was observed with both 0.64 mM ENU (1.95-fold increase, P < 0.0001), 1 {mu}M benzo(a)pyrene (1.87-fold increase, P = 0.0006) and 3 nM etoposide (1.89-fold increase, P = 0.0003). The putative ESTR mutagen okadaic acid (1.27-fold increase, P = 0.2289), administered at 0.5 nM, did not affect the C3H/10T1/2 Ms6-hm locus. Therefore, agents inducing small and bulky adducts, and indirectly causing strand breaks through inhibition of topoisomerase, caused similar induction of instability at an ESTR locus at matched toxicities. As size spectra for induced mutations were identical, the data indicate that although these chemicals exhibit distinct modes of action, a similar indirect process is influencing ESTR instability. In contrast, a potent tumour promoter that is a kinase inhibitor does not contribute to induced ESTR instability in

Instability of expanded simple tandem repeats is induced in cell culture by a variety of agents: N-Nitroso-N-ethylurea, benzo(a)pyrene, etoposide and okadaic acid

International Nuclear Information System (INIS)

Polyzos, Aris; Parfett, Craig; Healy, Caroline; Douglas, George R.; Yauk, Carole L.

2006-01-01

Expanded simple tandem repeat (ESTR) sequences have proven useful biomarkers to detect genotoxicity in vivo. Their high sensitivity has been used to assess environmentally relevant doses of mutagens such as ionizing radiation, DNA alkylating agents and airborne particulate pollution, for germline mutations in mouse assays. The mutagenic response involves size alteration of these ESTR loci induced by agents causing a variety of cellular damage. The mechanistic aspects of this induced instability remain unclear and have not been studied in detail. Mechanistic knowledge is important to help understand the relevance of increased ESTR mutation frequencies. In this study, we applied a murine cell culture system to examine induced response to four agents exhibiting different modes of toxic action including: N-nitroso-N-ethylurea (ENU), benzo(a)pyrene (BaP), okadaic acid and etoposide at slightly sub-toxic levels. We used single-molecule-polymerase chain reaction (SM-PCR) to assess the relative mutant frequency after 4-week chemical treatments at the Ms6-hm ESTR sequence of cultured C3H/10T1/2 cells (a mouse embryonic cell line). Increased mutation was observed with both 0.64 mM ENU (1.95-fold increase, P < 0.0001), 1 μM benzo(a)pyrene (1.87-fold increase, P = 0.0006) and 3 nM etoposide (1.89-fold increase, P = 0.0003). The putative ESTR mutagen okadaic acid (1.27-fold increase, P = 0.2289), administered at 0.5 nM, did not affect the C3H/10T1/2 Ms6-hm locus. Therefore, agents inducing small and bulky adducts, and indirectly causing strand breaks through inhibition of topoisomerase, caused similar induction of instability at an ESTR locus at matched toxicities. As size spectra for induced mutations were identical, the data indicate that although these chemicals exhibit distinct modes of action, a similar indirect process is influencing ESTR instability. In contrast, a potent tumour promoter that is a kinase inhibitor does not contribute to induced ESTR instability in cell

Effects of thermal and fast neutrons and of ENU on generations M3 and M4 of Lens culinaris (medicus)

International Nuclear Information System (INIS)

Uhlik, J.; Urban, J.

1976-01-01

Plants in which the selection of the most fertile plants had not been made in the preceding generations showed a significantly lower emergence rate in the M3 and M4 generation after an ethyl nitroso urea (ENU) application, in comparison with material treated with neutrons. In the evaluation of the plants obtained after an exposure to the most effective doses in the induction of chlorophyll mutants, significant differences of the average values in relation to the control were found in the M3 generation in the number of seeds per plant after the application of both neutron radiations and ENU. In addition, after the application of thermal neutrons and ENU a significant difference was found in the average values of plant weight. A difference in the overall range of variability in relation to the control was found in plant weight after the application of neutrons and ENU, and in seed weight after the application of ENU and fast neutrons. The differences between the treated plants and controls in the M4 generation plants with fusarium disease were insignificant. The evaluation of the progenies exposed to various doses of the highest mutation effectiveness showed in the M3 generation significant differences (in relation to the control) in the mean values of plant height, seed weight, plant weight, seed proportion in plants, in the bottom-pod insertion level, and in the number of pods set. Despite a considerable attack by fusarium disease, the greatest number of plants having more seeds than 50 was selected in the M4 generation of the material exposed to the dose of 8 fast neutrons (0.95% of plants) while in the control the proportion of highly fertile plants was only 0.05%. The widest range of overall variability in the characteristics under study was found after irradiation with thermal neutrons. From this viewpoint they can be recommended for wide practical utilization. (author)

Paradoxical effect of aspirin on the growth of C6 rat glioma and on time of development of ENU-induced tumors of the nervous system.

Science.gov (United States)

Arrieta, O; Guevara, P; Reyes, S; Palencia, G; Rivera, E; Sotelo, J

2001-11-01

Administration of acetylsalicylic acid (ASA), an inhibitor of the synthesis of prostaglandins and thrombzoxanes, decreases the incidence of colorectal cancer and other neoplasms and inhibits in vitro some tumor growth. We studied the effect of various doses of ASA on the growth of C6 glioma implanted in rats as well as the effect of chronic administration of ASA on time of development and incidence of tumors of the central nervous system (CNS) induced by prenatal exposure to ethylnitrosourea (ENU). In a controlled study, various doses of ASA, 12.5, 25, 50, 100, 200, 300, and 400 mg/kg per day, were administered to Wistar rats in whom a subcutaneous C6 glioma had been transplanted. Changes in tumor size, histologic characteristics, mitotic index, cell proliferation, and vascular density were studied. In a parallel experiment, we administered ASA (70 mg/kg per day) to rats who were prenatally exposed to ENU; treatment started on day 50 of age, and continued until the end of the experiment at day 400. The time of tumor development as well as incidence, localization, and histological diagnosis were compared with matched controls. A paradoxical effect of ASA administration was observed on the dynamics of cell proliferation of C6 glioma. When high ASA doses were administered (200 or 400 mg/kg per day), tumor volume, cell proliferation, vascular density, and mitotic index increased. In contrast, when low doses were administered (12.5 or 25 mg/kg per day) the tumor size diminished. In the second experiment, localization and incidence of CNS tumors induced by ENU were similar in animals treated with ASA and in controls; however, in rats treated with ASA the time of tumor development was shortened. The growth-promoting effects of high doses of ASA found in the present study in both transplanted and chemically-induced brain tumors, might be due to the blockage of autocrine inhibitory factors dependent on the cyclooxygenase pathway or by increased vascular permeability and

Enu mutagenesis identifies a novel platelet phenotype in a loss-of-function Jak2 allele.

Directory of Open Access Journals (Sweden)

Nicole M Anderson

Full Text Available Utilizing ENU mutagenesis, we identified a mutant mouse with elevated platelets. Genetic mapping localized the mutation to an interval on chromosome 19 that encodes the Jak2 tyrosine kinase. We identified a A3056T mutation resulting in a premature stop codon within exon 19 of Jak2 (Jak2(K915X, resulting in a protein truncation and functionally inactive enzyme. This novel platelet phenotype was also observed in mice bearing a hemizygous targeted disruption of the Jak2 locus (Jak2(+/-. Timed pregnancy experiments revealed that Jak2(K915X/K915X and Jak2(-/- displayed embryonic lethality; however, Jak2(K915X/K915X embryos were viable an additional two days compared to Jak2(-/- embryos. Our data suggest that perturbing JAK2 activation may have unexpected consequences in elevation of platelet number and correspondingly, important implications for treatment of hematological disorders with constitutive Jak2 activity.

Translational read-through of a nonsense mutation causing Bartter syndrome.

Science.gov (United States)

Cho, Hee Yeon; Lee, Beom Hee; Cheong, Hae Il

2013-06-01

Bartter syndrome (BS) is classified into 5 genotypes according to underlying mutant genes and BS III is caused by loss-of-function mutations in the CLCNKB gene encoding for basolateral ClC-Kb. BS III is the most common genotype in Korean patients with BS and W610X is the most common CLCNKB mutation in Korean BS III. In this study, we tested the hypothesis that the CLCNKB W610X mutation can be rescued in vitro using aminoglycoside antibiotics, which are known to induce translational read-through of a nonsense mutation. The CLCNKB cDNA was cloned into a eukaryotic expression vector and the W610X nonsense mutation was generated by site-directed mutagenesis. Cultured polarized MDCK cells were transfected with the vectors, and the read-through was induced using an aminoglycoside derivative, G418. Cellular expression of the target protein was monitored via immunohistochemistry. While cells transfected with the mutant CLCNKB failed to express ClC-Kb, G418 treatment of the cells induced the full-length protein expression, which was localized to the basolateral plasma membranes. It is demonstrated that the W610X mutation in CLCNKB can be a good candidate for trial of translational read-through induction as a therapeutic modality.

Inducible DNA-repair systems in yeast: competition for lesions.

Science.gov (United States)

Mitchel, R E; Morrison, D P

1987-03-01

DNA lesions may be recognized and repaired by more than one DNA-repair process. If two repair systems with different error frequencies have overlapping lesion specificity and one or both is inducible, the resulting variable competition for the lesions can change the biological consequences of these lesions. This concept was demonstrated by observing mutation in yeast cells (Saccharomyces cerevisiae) exposed to combinations of mutagens under conditions which influenced the induction of error-free recombinational repair or error-prone repair. Total mutation frequency was reduced in a manner proportional to the dose of 60Co-gamma- or 254 nm UV radiation delivered prior to or subsequent to an MNNG exposure. Suppression was greater per unit radiation dose in cells gamma-irradiated in O2 as compared to N2. A rad3 (excision-repair) mutant gave results similar to wild-type but mutation in a rad52 (rec-) mutant exposed to MNNG was not suppressed by radiation. Protein-synthesis inhibition with heat shock or cycloheximide indicated that it was the mutation due to MNNG and not that due to radiation which had changed. These results indicate that MNNG lesions are recognized by both the recombinational repair system and the inducible error-prone system, but that gamma-radiation induction of error-free recombinational repair resulted in increased competition for the lesions, thereby reducing mutation. Similarly, gamma-radiation exposure resulted in a radiation dose-dependent reduction in mutation due to MNU, EMS, ENU and 8-MOP + UVA, but no reduction in mutation due to MMS. These results suggest that the number of mutational MMS lesions recognizable by the recombinational repair system must be very small relative to those produced by the other agents. MNNG induction of the inducible error-prone systems however, did not alter mutation frequencies due to ENU or MMS exposure but, in contrast to radiation, increased the mutagenic effectiveness of EMS. These experiments demonstrate

Defective immuno- and thymoproteasome assembly causes severe immunodeficiency

DEFF Research Database (Denmark)

Treise, Irina; Huber, Eva M.; Klein-Rodewald, Tanja

2018-01-01

By N-ethyl-N-nitrosourea (ENU) mutagenesis, we generated the mutant mouse line TUB6 that is characterised by severe combined immunodeficiency (SCID) and systemic sterile autoinflammation in homozygotes, and a selective T cell defect in heterozygotes. The causative missense point mutation results...

Molecular analysis of mutant and wild type alcohol dehydrogenase alleles from Drosophila

International Nuclear Information System (INIS)

Batzer, M.A.

1988-01-01

Wild type alcohol dehydrogenase polypeptides (ADH) from Drosophila melanogaster transformants were examined using western blots and polyclonal antiserum specific for Drosophila melanogaster ADH. Mutants induced in Drosophila spermatozoa at the alcohol dehydrogenase (Adh) locus using X-rays, 1-ethyl-1-nitrosourea (ENU) or ethyl methanesulfonate (EMS) were characterized using genetic complementation tests, western blots, Southern blots, northern blots and enzymatic amplification of the Adh locus. Genetic complementation tests showed that 22/30 X-ray-induced mutants, and 3/13 ENU and EMS induced mutants were multi-locus deficiencies. Western blot analysis of the intragenic mutations showed that 4/7 X-ray-induced mutants produced detectable polypeptides, one of which was normal in molecular weight and charge. In contrast 8/10 intragenic ENU and EMS induced mutants produced normal polypeptides. Southern blot analysis showed that 5/7 intragenic X-ray induced mutants and all 10 of the intragenic ENU and EMS induced mutants were normal with respect to the alleles they were derived from

Radiation-induced mutations and plant breeding

International Nuclear Information System (INIS)

Naqvi, S.H.M.

1985-01-01

Ionizing radiation could cause genetic changes in an organism and could modify gene linkages. The induction of mutation through radiation is random and the probability of getting the desired genetic change is low but can be increased by manipulating different parameters such as dose rate, physical conditions under which the material has been irradiated, etc. Induced mutations have been used as a supplement to conventional plant breeding, particularly for creating genetic variability for specific characters such as improved plant structure, pest and disease resistance, and desired changes in maturity period; more than 200 varieties of crop plants have been developed by this technique. The Pakistan Atomic Energy Commission has used this technique fruitfully to evolve better germplasm in cotton, rice, chickpea, wheat and mungbean; some of the mutants have become popular commercial varieties. This paper describes some uses of radiation induced mutations and the results achieved in Pakistan so far

CSB-PGBD3 Mutations Cause Premature Ovarian Failure.

Directory of Open Access Journals (Sweden)

Yingying Qin

2015-07-01

Full Text Available Premature ovarian failure (POF is a rare, heterogeneous disorder characterized by cessation of menstruation occurring before the age of 40 years. Genetic etiology is responsible for perhaps 25% of cases, but most cases are sporadic and unexplained. In this study, through whole exome sequencing in a non-consanguineous family having four affected members with POF and Sanger sequencing in 432 sporadic cases, we identified three novel mutations in the fusion gene CSB-PGBD3. Subsequently functional studies suggest that mutated CSB-PGBD3 fusion protein was impaired in response to DNA damage, as indicated by delayed or absent recruitment to damaged sites. Our data provide the first evidence that mutations in the CSB-PGBD3 fusion protein can cause human disease, even in the presence of functional CSB, thus potentially explaining conservation of the fusion protein for 43 My since marmoset. The localization of the CSB-PGBD3 fusion protein to UVA-induced nuclear DNA repair foci further suggests that the CSB-PGBD3 fusion protein, like many other proteins that can cause POF, modulates or participates in DNA repair.

Use of γ-ray-induced mutations in the genome era in rice

International Nuclear Information System (INIS)

Kusaba, Makoto

2007-01-01

Ionizing radiation has been used for inducing mutations and improving crops since the discovery by STADLER (1928) that X-rays could induce mutations in barley. At the end of 2004, the whole genome sequence of rice was determined (INTERNATIONAL RICE GENOME SEQUENCING PROJECT, 2005). What can γ-ray-induced mutations contribute now that this has been achieved? One answer could be the elucidation of the functions of the numerous genes revealed by the complete sequence of the rice genome. This includes identification of mutants through reverse genetics and the isolation of genes containing mutations through forward genetics using molecular markers and sequence information. Another answer could be mutation breeding using reverse genetics. But first we must know what kind of DNA lesions are caused by γ-rays. In this article, I describe the production of DNA lesions, and then discuss how γ-ray-induced mutations can contribute to the elucidation of gene function and to mutation breeding. (author)

ENU-mutagenesis mice with a non-synonymous mutation in Grin1 exhibit abnormal anxiety-like behaviors, impaired fear memory, and decreased acoustic startle response

Science.gov (United States)

2013-01-01

Background The Grin1 (glutamate receptor, ionotropic, NMDA1) gene expresses a subunit of N-methyl-D-aspartate (NMDA) receptors that is considered to play an important role in excitatory neurotransmission, synaptic plasticity, and brain development. Grin1 is a candidate susceptibility gene for neuropsychiatric disorders, including schizophrenia, bipolar disorder, and attention deficit/hyperactivity disorder (ADHD). In our previous study, we examined an N-ethyl-N-nitrosourea (ENU)-generated mutant mouse strain (Grin1Rgsc174/Grin1+) that has a non-synonymous mutation in Grin1. These mutant mice showed hyperactivity, increased novelty-seeking to objects, and abnormal social interactions. Therefore, Grin1Rgsc174/Grin1+ mice may serve as a potential animal model of neuropsychiatric disorders. However, other behavioral characteristics related to these disorders, such as working memory function and sensorimotor gating, have not been fully explored in these mutant mice. In this study, to further investigate the behavioral phenotypes of Grin1Rgsc174/Grin1+ mice, we subjected them to a comprehensive battery of behavioral tests. Results There was no significant difference in nociception between Grin1Rgsc174/Grin1+ and wild-type mice. The mutants did not display any abnormalities in the Porsolt forced swim and tail suspension tests. We confirmed the previous observations that the locomotor activity of these mutant mice increased in the open field and home cage activity tests. They displayed abnormal anxiety-like behaviors in the light/dark transition and the elevated plus maze tests. Both contextual and cued fear memory were severely deficient in the fear conditioning test. The mutant mice exhibited slightly impaired working memory in the eight-arm radial maze test. The startle amplitude was markedly decreased in Grin1Rgsc174/Grin1+ mice, whereas no significant differences between genotypes were detected in the prepulse inhibition (PPI) test. The mutant mice showed no obvious

Noonan syndrome gain-of-function mutations in NRAS cause zebrafish gastrulation defects

Directory of Open Access Journals (Sweden)

Vincent Runtuwene

2011-05-01

Noonan syndrome is a relatively common developmental disorder that is characterized by reduced growth, wide-set eyes and congenital heart defects. Noonan syndrome is associated with dysregulation of the Ras–mitogen-activated-protein-kinase (MAPK signaling pathway. Recently, two mutations in NRAS were reported to be associated with Noonan syndrome, T50I and G60E. Here, we report a mutation in NRAS, resulting in an I24N amino acid substitution, that we identified in an individual bearing typical Noonan syndrome features. The I24N mutation activates N-Ras, resulting in enhanced downstream signaling. Expression of N-Ras-I24N, N-Ras-G60E or the strongly activating mutant N-Ras-G12V, which we included as a positive control, results in developmental defects in zebrafish embryos, demonstrating that these activating N-Ras mutants are sufficient to induce developmental disorders. The defects in zebrafish embryos are reminiscent of symptoms in individuals with Noonan syndrome and phenocopy the defects that other Noonan-syndrome-associated genes induce in zebrafish embryos. MEK inhibition completely rescued the activated N-Ras-induced phenotypes, demonstrating that these defects are mediated exclusively by Ras-MAPK signaling. In conclusion, mutations in NRAS from individuals with Noonan syndrome activated N-Ras signaling and induced developmental defects in zebrafish embryos, indicating that activating mutations in NRAS cause Noonan syndrome.

Noonan syndrome gain-of-function mutations in NRAS cause zebrafish gastrulation defects

Science.gov (United States)

Runtuwene, Vincent; van Eekelen, Mark; Overvoorde, John; Rehmann, Holger; Yntema, Helger G.; Nillesen, Willy M.; van Haeringen, Arie; van der Burgt, Ineke; Burgering, Boudewijn; den Hertog, Jeroen

2011-01-01

SUMMARY Noonan syndrome is a relatively common developmental disorder that is characterized by reduced growth, wide-set eyes and congenital heart defects. Noonan syndrome is associated with dysregulation of the Ras–mitogen-activated-protein-kinase (MAPK) signaling pathway. Recently, two mutations in NRAS were reported to be associated with Noonan syndrome, T50I and G60E. Here, we report a mutation in NRAS, resulting in an I24N amino acid substitution, that we identified in an individual bearing typical Noonan syndrome features. The I24N mutation activates N-Ras, resulting in enhanced downstream signaling. Expression of N-Ras-I24N, N-Ras-G60E or the strongly activating mutant N-Ras-G12V, which we included as a positive control, results in developmental defects in zebrafish embryos, demonstrating that these activating N-Ras mutants are sufficient to induce developmental disorders. The defects in zebrafish embryos are reminiscent of symptoms in individuals with Noonan syndrome and phenocopy the defects that other Noonan-syndrome-associated genes induce in zebrafish embryos. MEK inhibition completely rescued the activated N-Ras-induced phenotypes, demonstrating that these defects are mediated exclusively by Ras-MAPK signaling. In conclusion, mutations in NRAS from individuals with Noonan syndrome activated N-Ras signaling and induced developmental defects in zebrafish embryos, indicating that activating mutations in NRAS cause Noonan syndrome. PMID:21263000

Recurrent LDL-receptor mutation causes familial ...

African Journals Online (AJOL)

1995-05-05

May 5, 1995 ... 3. eaudet . New. Recurrent LDL-receptor mutation causes familial hypercholesterolaemia in ... amplification refractory mutation system (ARMS)" and single- strand conformation .... Location. Afrikaner. Mixed race. ApaLl.

Molecular mechanisms of induced-mutations

International Nuclear Information System (INIS)

Kato, Takeshi

1985-01-01

The outcome of recent studies on mechanisms of induced-mutations is outlined with particular emphasis on the dependence of recA gene function in Escherichia coli. Genes involved in spontaneous mutation and x-ray- and chemical-induced mutation and genes involved in adaptive response are presented. As for SOS mutagenesis, SOS-induced regulation mechanisms and mutagenic routes are described. Furthermore, specificity of mutagens themselves are discussed in relation to mechanisms of base substitution, frameshift, and deletion mutagenesis. (Namekawa, K.)

Mutations induced by ultraviolet light

International Nuclear Information System (INIS)

Pfeifer, Gerd P.; You, Young-Hyun; Besaratinia, Ahmad

2005-01-01

The different ultraviolet (UV) wavelength components, UVA (320-400 nm), UVB (280-320 nm), and UVC (200-280 nm), have distinct mutagenic properties. A hallmark of UVC and UVB mutagenesis is the high frequency of transition mutations at dipyrimidine sequences containing cytosine. In human skin cancers, about 35% of all mutations in the p53 gene are transitions at dipyrimidines within the sequence 5'-TCG and 5'-CCG, and these are localized at several mutational hotspots. Since 5'-CG sequences are methylated along the p53 coding sequence in human cells, these mutations may be derived from sunlight-induced pyrimidine dimers forming at sequences that contain 5-methylcytosine. Cyclobutane pyrimidine dimers (CPDs) form preferentially at dipyrimidines containing 5-methylcytosine when cells are irradiated with UVB or sunlight. In order to define the contribution of 5-methylcytosine to sunlight-induced mutations, the lacI and cII transgenes in mouse fibroblasts were used as mutational targets. After 254 nm UVC irradiation, only 6-9% of the base substitutions were at dipyrimidines containing 5-methylcytosine. However, 24-32% of the solar light-induced mutations were at dipyrimidines that contain 5-methylcytosine and most of these mutations were transitions. Thus, CPDs forming preferentially at dipyrimidines with 5-methylcytosine are responsible for a considerable fraction of the mutations induced by sunlight in mammalian cells. Using mouse cell lines harboring photoproduct-specific photolyases and mutational reporter genes, we showed that CPDs (rather than 6-4 photoproducts or other lesions) are responsible for the great majority of UVB-induced mutations. An important component of UVB mutagenesis is the deamination of cytosine and 5-methylcytosine within CPDs. The mutational specificity of long-wave UVA (340-400 nm) is distinct from that of the shorter wavelength UV and is characterized mainly by G to T transversions presumably arising through mechanisms involving oxidized DNA

Mutations in KEOPS-complex genes cause nephrotic syndrome with primary microcephaly.

Science.gov (United States)

Braun, Daniela A; Rao, Jia; Mollet, Geraldine; Schapiro, David; Daugeron, Marie-Claire; Tan, Weizhen; Gribouval, Olivier; Boyer, Olivia; Revy, Patrick; Jobst-Schwan, Tilman; Schmidt, Johanna Magdalena; Lawson, Jennifer A; Schanze, Denny; Ashraf, Shazia; Ullmann, Jeremy F P; Hoogstraten, Charlotte A; Boddaert, Nathalie; Collinet, Bruno; Martin, Gaëlle; Liger, Dominique; Lovric, Svjetlana; Furlano, Monica; Guerrera, I Chiara; Sanchez-Ferras, Oraly; Hu, Jennifer F; Boschat, Anne-Claire; Sanquer, Sylvia; Menten, Björn; Vergult, Sarah; De Rocker, Nina; Airik, Merlin; Hermle, Tobias; Shril, Shirlee; Widmeier, Eugen; Gee, Heon Yung; Choi, Won-Il; Sadowski, Carolin E; Pabst, Werner L; Warejko, Jillian K; Daga, Ankana; Basta, Tamara; Matejas, Verena; Scharmann, Karin; Kienast, Sandra D; Behnam, Babak; Beeson, Brendan; Begtrup, Amber; Bruce, Malcolm; Ch'ng, Gaik-Siew; Lin, Shuan-Pei; Chang, Jui-Hsing; Chen, Chao-Huei; Cho, Megan T; Gaffney, Patrick M; Gipson, Patrick E; Hsu, Chyong-Hsin; Kari, Jameela A; Ke, Yu-Yuan; Kiraly-Borri, Cathy; Lai, Wai-Ming; Lemyre, Emmanuelle; Littlejohn, Rebecca Okashah; Masri, Amira; Moghtaderi, Mastaneh; Nakamura, Kazuyuki; Ozaltin, Fatih; Praet, Marleen; Prasad, Chitra; Prytula, Agnieszka; Roeder, Elizabeth R; Rump, Patrick; Schnur, Rhonda E; Shiihara, Takashi; Sinha, Manish D; Soliman, Neveen A; Soulami, Kenza; Sweetser, David A; Tsai, Wen-Hui; Tsai, Jeng-Daw; Topaloglu, Rezan; Vester, Udo; Viskochil, David H; Vatanavicharn, Nithiwat; Waxler, Jessica L; Wierenga, Klaas J; Wolf, Matthias T F; Wong, Sik-Nin; Leidel, Sebastian A; Truglio, Gessica; Dedon, Peter C; Poduri, Annapurna; Mane, Shrikant; Lifton, Richard P; Bouchard, Maxime; Kannu, Peter; Chitayat, David; Magen, Daniella; Callewaert, Bert; van Tilbeurgh, Herman; Zenker, Martin; Antignac, Corinne; Hildebrandt, Friedhelm

2017-10-01

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.

Mutations in SYNGAP1 Cause Intellectual Disability, Autism, and a Specific Form of Epilepsy by Inducing Haploinsufficiency

DEFF Research Database (Denmark)

Berryer, Martin H; Hamdan, Fadi F; Klitten, Laura L

2013-01-01

De novo mutations in SYNGAP1, which codes for a RAS/RAP GTP-activating protein, cause nonsyndromic intellectual disability (NSID). All disease-causing point mutations identified until now in SYNGAP1 are truncating, raising the possibility of an association between this type of mutations and NSID...... also showed ataxia, autism, and a specific form of generalized epilepsy that can be refractory to treatment. All of these mutations occurred de novo, except c.283dupC, which was inherited from a father who is a mosaic. Biolistic transfection of wild-type SYNGAP1 in pyramidal cells from cortical...

High-resolution melting curve analysis for rapid detection of mutations in a Medaka TILLING library

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Deguchi Tomonori

2010-09-01

Full Text Available Abstract Background During the last two decades, DNA sequencing has led to the identification of numerous genes in key species; however, in most cases, their functions are still unknown. In this situation, reverse genetics is the most suitable method to assign function to a gene. TILLING (Targeting Induced Local Lesions IN Genomes is a reverse-genetic strategy that combines random chemical mutagenesis with high-throughput discovery of the induced mutations in target genes. The method has been applied to a variety of plant and animal species. Screening of the induced mutations is the most important step in TILLING. Currently, direct sequencing or nuclease-mediated screening of heteroduplexes is widely used for detection of mutations in TILLING. Both methods are useful, but the costs are substantial and turnaround times are relatively long. Thus, there is a need for an alternative method that is of higher throughput and more cost effective. Results In this study, we developed a high resolution melting (HRM assay and evaluated its effectiveness for screening ENU-induced mutations in a medaka TILLING library. We had previously screened mutations in the p53 gene by direct sequencing. Therefore, we first tested the efficiency of the HRM assay by screening mutations in p53, which indicated that the HRM assay is as useful as direct sequencing. Next, we screened mutations in the atr and atm genes with the HRM assay. Nonsense mutations were identified in each gene, and the phenotypes of these nonsense mutants confirmed their loss-of-function nature. Conclusions These results demonstrate that the HRM assay is useful for screening mutations in TILLING. Furthermore, the phenotype of the obtained mutants indicates that medaka is an excellent animal model for investigating genome stability and gene function, especially when combined with TILLING.

Mutations induced in plant breeding

International Nuclear Information System (INIS)

Barriga B, P.

1984-01-01

The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented. (Author)

Mutations induced in plant breeding

Energy Technology Data Exchange (ETDEWEB)

Barriga B, P. (Universidad Austral de Chile, Valdivia. Inst. de Produccion y Sanidad Vegetal)

1984-10-01

The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented.

Gene repair of an Usher syndrome causing mutation by zinc-finger nuclease mediated homologous recombination.

Science.gov (United States)

Overlack, Nora; Goldmann, Tobias; Wolfrum, Uwe; Nagel-Wolfrum, Kerstin

2012-06-26

Human Usher syndrome (USH) is the most frequent cause of inherited deaf-blindness. It is clinically and genetically heterogeneous, assigned to three clinical types of which the most severe type is USH1. No effective treatment for the ophthalmic component of USH exists. Gene augmentation is an attractive strategy for hereditary retinal diseases. However, several USH genes, like USH1C, are expressed in various isoforms, hampering gene augmentation. As an alternative treatment strategy, we applied the zinc-finger nuclease (ZFN) technology for targeted gene repair of an USH1C, causing mutation by homologous recombination. We designed ZFNs customized for the p.R31X nonsense mutation in Ush1c. We evaluated ZFNs for DNA cleavage capability and analyzed ZFNs biocompatibilities by XTT assays. We demonstrated ZFNs mediated gene repair on genomic level by digestion assays and DNA sequencing, and on protein level by indirect immunofluorescence and Western blot analyses. The specifically designed ZFNs did not show cytotoxic effects in a p.R31X cell line. We demonstrated that ZFN induced cleavage of their target sequence. We showed that simultaneous application of ZFN and rescue DNA induced gene repair of the disease-causing mutation on the genomic level, resulting in recovery of protein expression. In our present study, we analyzed for the first time ZFN-activated gene repair of an USH gene. The data highlight the ability of ZFNs to induce targeted homologous recombination and mediate gene repair in USH. We provide further evidence that the ZFN technology holds great potential to recover disease-causing mutations in inherited retinal disorders.

The rad2 mutation affects the molecular nature of UV and acridine-mustard-induced mutations in the ADE2 gene of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Ivanov, E.L.; Kovaltzova, S.V.; Kassinova, G.V.; Gracheva, L.M.; Korolev, V.G.; Zakharov, I.A.

1986-01-01

The authors have studied the molecular nature of ade2 mutations induced by UV light and bifunctional acridine-mustard (BAM) in wild-type (RAD) and in excision-deficient (rad2) strains of the yeast, Saccharomyces cerevisiae. In the RAD strain, UV causes 45% GC → AT transitions among all mutations; in the rad2 strain this value is 77%. BAM was shown to be highly specific for frameshift mutagenesis: 60% frameshifts in the RAD strain, and as many as 84% frameshifts in the rad2 strain were induced. Therefore, the rad2 mutation affects the specificity of UV- and BAM-induced mutagenesis in yeast. Experimental data agree with the view that the majority of mutations in the RAD strain are induced by a prereplicative mechanism, whereas mutations in the rad2 strain are predominantly postreplicative events. (Auth.)

Cauli: a mouse strain with an Ift140 mutation that results in a skeletal ciliopathy modelling Jeune syndrome.

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Kerry A Miller

2013-08-01

Full Text Available Cilia are architecturally complex organelles that protrude from the cell membrane and have signalling, sensory and motility functions that are central to normal tissue development and homeostasis. There are two broad categories of cilia; motile and non-motile, or primary, cilia. The central role of primary cilia in health and disease has become prominent in the past decade with the recognition of a number of human syndromes that result from defects in the formation or function of primary cilia. This rapidly growing class of conditions, now known as ciliopathies, impact the development of a diverse range of tissues including the neural axis, craniofacial structures, skeleton, kidneys, eyes and lungs. The broad impact of cilia dysfunction on development reflects the pivotal position of the primary cilia within a signalling nexus involving a growing number of growth factor systems including Hedgehog, Pdgf, Fgf, Hippo, Notch and both canonical Wnt and planar cell polarity. We have identified a novel ENU mutant allele of Ift140, which causes a mid-gestation embryonic lethal phenotype in homozygous mutant mice. Mutant embryos exhibit a range of phenotypes including exencephaly and spina bifida, craniofacial dysmorphism, digit anomalies, cardiac anomalies and somite patterning defects. A number of these phenotypes can be attributed to alterations in Hedgehog signalling, although additional signalling systems are also likely to be involved. We also report the identification of a homozygous recessive mutation in IFT140 in a Jeune syndrome patient. This ENU-induced Jeune syndrome model will be useful in delineating the origins of dysmorphology in human ciliopathies.

Physiological Expression of AMPKγ2RG Mutation Causes Wolff-Parkinson-White Syndrome and Induces Kidney Injury in Mice.

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Yang, Xiaodong; Mudgett, John; Bou-About, Ghina; Champy, Marie-France; Jacobs, Hugues; Monassier, Laurent; Pavlovic, Guillaume; Sorg, Tania; Herault, Yann; Petit-Demoulière, Benoit; Lu, Ku; Feng, Wen; Wang, Hongwu; Ma, Li-Jun; Askew, Roger; Erion, Mark D; Kelley, David E; Myers, Robert W; Li, Cai; Guan, Hong-Ping

2016-11-04

Mutations of the AMP-activated kinase gamma 2 subunit (AMPKγ2), N488I (AMPKγ2 NI ) and R531G (AMPKγ2 RG ), are associated with Wolff-Parkinson-White (WPW) syndrome, a cardiac disorder characterized by ventricular pre-excitation in humans. Cardiac-specific transgenic overexpression of human AMPKγ2 NI or AMPKγ2 RG leads to constitutive AMPK activation and the WPW phenotype in mice. However, overexpression of these mutant proteins also caused profound, non-physiological increase in cardiac glycogen, which might abnormally alter the true phenotype. To investigate whether physiological levels of AMPKγ2 NI or AMPKγ2 RG mutation cause WPW syndrome and metabolic changes in other organs, we generated two knock-in mouse lines on the C57BL/6N background harboring mutations of human AMPKγ2 NI and AMPKγ2 RG , respectively. Similar to the reported phenotypes of mice overexpressing AMPKγ2 NI or AMPKγ2 RG in the heart, both lines developed WPW syndrome and cardiac hypertrophy; however, these effects were independent of cardiac glycogen accumulation. Compared with AMPKγ2 WT mice, AMPKγ2 NI and AMPKγ2 RG mice exhibited reduced body weight, fat mass, and liver steatosis when fed with a high fat diet (HFD). Surprisingly, AMPKγ2 RG but not AMPKγ2 NI mice fed with an HFD exhibited severe kidney injury characterized by glycogen accumulation, inflammation, apoptosis, cyst formation, and impaired renal function. These results demonstrate that expression of AMPKγ2 NI and AMPKγ2 RG mutations at physiological levels can induce beneficial metabolic effects but that this is accompanied by WPW syndrome. Our data also reveal an unexpected effect of AMPKγ2 RG in the kidney, linking lifelong constitutive activation of AMPK to a potential risk for kidney dysfunction in the context of an HFD. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Physiological Expression of AMPKγ2RG Mutation Causes Wolff-Parkinson-White Syndrome and Induces Kidney Injury in Mice*

Science.gov (United States)

Yang, Xiaodong; Mudgett, John; Bou-About, Ghina; Champy, Marie-France; Jacobs, Hugues; Monassier, Laurent; Pavlovic, Guillaume; Sorg, Tania; Herault, Yann; Petit-Demoulière, Benoit; Lu, Ku; Feng, Wen; Wang, Hongwu; Ma, Li-Jun; Askew, Roger; Erion, Mark D.; Kelley, David E.; Myers, Robert W.; Li, Cai

2016-01-01

Mutations of the AMP-activated kinase gamma 2 subunit (AMPKγ2), N488I (AMPKγ2NI) and R531G (AMPKγ2RG), are associated with Wolff-Parkinson-White (WPW) syndrome, a cardiac disorder characterized by ventricular pre-excitation in humans. Cardiac-specific transgenic overexpression of human AMPKγ2NI or AMPKγ2RG leads to constitutive AMPK activation and the WPW phenotype in mice. However, overexpression of these mutant proteins also caused profound, non-physiological increase in cardiac glycogen, which might abnormally alter the true phenotype. To investigate whether physiological levels of AMPKγ2NI or AMPKγ2RG mutation cause WPW syndrome and metabolic changes in other organs, we generated two knock-in mouse lines on the C57BL/6N background harboring mutations of human AMPKγ2NI and AMPKγ2RG, respectively. Similar to the reported phenotypes of mice overexpressing AMPKγ2NI or AMPKγ2RG in the heart, both lines developed WPW syndrome and cardiac hypertrophy; however, these effects were independent of cardiac glycogen accumulation. Compared with AMPKγ2WT mice, AMPKγ2NI and AMPKγ2RG mice exhibited reduced body weight, fat mass, and liver steatosis when fed with a high fat diet (HFD). Surprisingly, AMPKγ2RG but not AMPKγ2NI mice fed with an HFD exhibited severe kidney injury characterized by glycogen accumulation, inflammation, apoptosis, cyst formation, and impaired renal function. These results demonstrate that expression of AMPKγ2NI and AMPKγ2RG mutations at physiological levels can induce beneficial metabolic effects but that this is accompanied by WPW syndrome. Our data also reveal an unexpected effect of AMPKγ2RG in the kidney, linking lifelong constitutive activation of AMPK to a potential risk for kidney dysfunction in the context of an HFD. PMID:27621313

Molecular analysis of radiation-induced albino (c)-locus mutations that cause death at preimplantation stages of development

International Nuclear Information System (INIS)

Rinchik, E.M.; Toenjes, R.R.; Paul, D.; Potter, M.D.

1993-01-01

Deletion mutations at the albino (c) locus have been useful for continuing the development of fine-structure physical and functional maps of the Fes-Hbb region of mouse chromosome 7. This report describes the molecular analysis of a number of radiation-induced c deletions that, when homozygous, cause death of the embryo during preimplantation stages. The distal extent of these deletions defines a locus, pid, (preimplantation development) genetically associated with this phenotype. The proximal breakpoints of eight of these deletions were mapped with respect to the Tyr (tyrosinase; albino) gene as well as to anonymous loci within the Fah-Tyr region that are defined by the Pmv-31 viral integration site and by chromosome-microdissection clones. Rearrangements corresponding to the proximal breakpoints of two of these deletions were detected by Southern blot analysis, and a size-altered restriction fragment carrying the breakpoint of one of them was cloned. A probe derived from this deletion fusion fragment defines a locus, D7Rn6, which maps within (or distal to) the pid region, and which discriminates among the distal extents of deletions eliciting the pid phenotype. Extension of physical maps from D7Rn6 should provide access both to the pid region and to loci mapping distal to pid that are defined by N-ethyl-N-nitrosourea-induced lethal mutations. 36 refs., 10 figs

Molecular mechanisms of mutagenesis determined by the recombinant DNA technology

International Nuclear Information System (INIS)

Lee, W.R.

1985-01-01

A study of the alteration of the DNA in the mutant gene can determine mechanisms of mutation by distinguishing between mutations induced by transition, transversion, frameshifts of a single base and deletions involving many base pairs. The association of a specific pattern of response with a mutagen will permit detecting mutants induced by the mutagen with a reduced background by removing mutations induced by other mechanisms from the pool of potential mutants. From analyses of studies that have been conducted, it is quite apparent that there are substantial differences among mutagens in their modes of action. Of 31 x-ray induced mutants, 20 were large deletions while only 3 showed normal Southern blots. Only one mutant produced a sub-unit polypeptide of normal molecular weight and charge in the in vivo test whereas in vitro synthesis produced a second one. In contrast, nine of thirteen EMS induced mutants produced cross-reacting proteins with sub-unit polypeptide molecular weights equivalent to wild type. Two of three ENU induced mutants recently analyzed in our laboratory produced protein with sub-unit polypeptide molecular weight and electrical charge similar to the wild type stock in which the mutants were induced. One ENU induced mutation is a large deletion. 21 refs., 1 fig

Mutations in Mll2, an H3K4 Methyltransferase, Result in Insulin Resistance and Impaired Glucose Tolerance in Mice

Science.gov (United States)

Schröter, David; Matthews, Helen C.; Bogani, Debora; Moir, Lee; Long, Anna; Church, Christopher; Hugill, Alison; Anstee, Quentin M.; Goldin, Rob; Thursz, Mark; Hollfelder, Florian; Cox, Roger D.

2013-01-01

We employed a random mutagenesis approach to identify novel monogenic determinants of type 2 diabetes. Here we show that haplo-insufficiency of the histone methyltransferase myeloid-lineage leukemia (Mll2/Wbp7) gene causes type 2 diabetes in the mouse. We have shown that mice heterozygous for two separate mutations in the SET domain of Mll2 or heterozygous Mll2 knockout mice were hyperglycaemic, hyperinsulinaemic and developed non-alcoholic fatty liver disease. Consistent with previous Mll2 knockout studies, mice homozygous for either ENU mutation (or compound heterozygotes) died during embryonic development at 9.5–14.5 days post coitum. Heterozygous deletion of Mll2 induced in the adult mouse results in a normal phenotype suggesting that changes in chromatin methylation during development result in the adult phenotype. Mll2 has been shown to regulate a small subset of genes, a number of which Neurod1, Enpp1, Slc27a2, and Plcxd1 are downregulated in adult mutant mice. Our results demonstrate that histone H3K4 methyltransferase Mll2 is a component of the genetic regulation necessary for glucose homeostasis, resulting in a specific disease pattern linking chromatin modification with causes and progression of type 2 diabetes, providing a basis for its further understanding at the molecular level. PMID:23826075

Mutations in Mll2, an H3K4 methyltransferase, result in insulin resistance and impaired glucose tolerance in mice.

Directory of Open Access Journals (Sweden)

Michelle Goldsworthy

Full Text Available We employed a random mutagenesis approach to identify novel monogenic determinants of type 2 diabetes. Here we show that haplo-insufficiency of the histone methyltransferase myeloid-lineage leukemia (Mll2/Wbp7 gene causes type 2 diabetes in the mouse. We have shown that mice heterozygous for two separate mutations in the SET domain of Mll2 or heterozygous Mll2 knockout mice were hyperglycaemic, hyperinsulinaemic and developed non-alcoholic fatty liver disease. Consistent with previous Mll2 knockout studies, mice homozygous for either ENU mutation (or compound heterozygotes died during embryonic development at 9.5-14.5 days post coitum. Heterozygous deletion of Mll2 induced in the adult mouse results in a normal phenotype suggesting that changes in chromatin methylation during development result in the adult phenotype. Mll2 has been shown to regulate a small subset of genes, a number of which Neurod1, Enpp1, Slc27a2, and Plcxd1 are downregulated in adult mutant mice. Our results demonstrate that histone H3K4 methyltransferase Mll2 is a component of the genetic regulation necessary for glucose homeostasis, resulting in a specific disease pattern linking chromatin modification with causes and progression of type 2 diabetes, providing a basis for its further understanding at the molecular level.

Ultraviolet-induced mutations in Cockayne syndrome cells are primarily caused by cyclobutane dimer photoproducts while repair of other photoproducts is normal

International Nuclear Information System (INIS)

Parris, C.N.; Kraemer, K.H.

1993-01-01

The authors compared the contribution to mutagenesis on Cockayne syndrome (CS) cells of the major class of UV photoproducts, the cyclobutane pyrimidine dimer, to that of other DNA photoproducts by using the mutagenesis shuttle vector pZ189. Lymphoblastoid cell lines from the DNA repair-deficient disorders CS and xeroderma pigmentosum (XP) and a normal line were transfected with UV-treated pZ189. Cyclobutane dimers were selectively removed before transfection by photoreactivation (PR), leaving nondimer photoproducts intact. After UV exposure and replication in CS and XP cells, plasmid survival was abnormally elevated. After PR, plasmid survival increased and mutation frequency in CS cells decreased to normal levels but remained abnormal in XP cells. Sequence analysis of >200 mutant plasmids showed that with CS cells a major mutational hot spot was caused by unrepaired cyclobutane dimers. These data indicate that with both CS and XP cyclobutane dimers are major photoproducts generating reduced plasmid survival and increased mutation frequency. However, unlike XP, CS cells are proficient in repair of nondimer photoproducts. Since XP but not CS patients have a high frequency of UV-induced skin cancers, the data suggest that prevention of UV-induced skin cancers is associated with proficient repair of nondimer photoproducts. 38 refs., 3 figs., 2 tabs

PPIB mutations cause severe osteogenesis imperfecta.

Science.gov (United States)

van Dijk, Fleur S; Nesbitt, Isabel M; Zwikstra, Eline H; Nikkels, Peter G J; Piersma, Sander R; Fratantoni, Silvina A; Jimenez, Connie R; Huizer, Margriet; Morsman, Alice C; Cobben, Jan M; van Roij, Mirjam H H; Elting, Mariet W; Verbeke, Jonathan I M L; Wijnaendts, Liliane C D; Shaw, Nick J; Högler, Wolfgang; McKeown, Carole; Sistermans, Erik A; Dalton, Ann; Meijers-Heijboer, Hanne; Pals, Gerard

2009-10-01

Deficiency of cartilage-associated protein (CRTAP) or prolyl 3-hydroxylase 1(P3H1) has been reported in autosomal-recessive lethal or severe osteogenesis imperfecta (OI). CRTAP, P3H1, and cyclophilin B (CyPB) form an intracellular collagen-modifying complex that 3-hydroxylates proline at position 986 (P986) in the alpha1 chains of collagen type I. This 3-prolyl hydroxylation is decreased in patients with CRTAP and P3H1 deficiency. It was suspected that mutations in the PPIB gene encoding CyPB would also cause OI with decreased collagen 3-prolyl hydroxylation. To our knowledge we present the first two families with recessive OI caused by PPIB gene mutations. The clinical phenotype is compatible with OI Sillence type II-B/III as seen with COL1A1/2, CRTAP, and LEPRE1 mutations. The percentage of 3-hydroxylated P986 residues in patients with PPIB mutations is decreased in comparison to normal, but it is higher than in patients with CRTAP and LEPRE1 mutations. This result and the fact that CyPB is demonstrable independent of CRTAP and P3H1, along with reported decreased 3-prolyl hydroxylation due to deficiency of CRTAP lacking the catalytic hydroxylation domain and the known function of CyPB as a cis-trans isomerase, suggest that recessive OI is caused by a dysfunctional P3H1/CRTAP/CyPB complex rather than by the lack of 3-prolyl hydroxylation of a single proline residue in the alpha1 chains of collagen type I.

Mutations in the NHEJ component XRCC4 cause primordial dwarfism.

Science.gov (United States)

Murray, Jennie E; van der Burg, Mirjam; IJspeert, Hanna; Carroll, Paula; Wu, Qian; Ochi, Takashi; Leitch, Andrea; Miller, Edward S; Kysela, Boris; Jawad, Alireza; Bottani, Armand; Brancati, Francesco; Cappa, Marco; Cormier-Daire, Valerie; Deshpande, Charu; Faqeih, Eissa A; Graham, Gail E; Ranza, Emmanuelle; Blundell, Tom L; Jackson, Andrew P; Stewart, Grant S; Bicknell, Louise S

2015-03-05

Non-homologous end joining (NHEJ) is a key cellular process ensuring genome integrity. Mutations in several components of the NHEJ pathway have been identified, often associated with severe combined immunodeficiency (SCID), consistent with the requirement for NHEJ during V(D)J recombination to ensure diversity of the adaptive immune system. In contrast, we have recently found that biallelic mutations in LIG4 are a common cause of microcephalic primordial dwarfism (MPD), a phenotype characterized by prenatal-onset extreme global growth failure. Here we provide definitive molecular genetic evidence supported by biochemical, cellular, and immunological data for mutations in XRCC4, encoding the obligate binding partner of LIG4, causing MPD. We report the identification of biallelic mutations in XRCC4 in five families. Biochemical and cellular studies demonstrate that these alterations substantially decrease XRCC4 protein levels leading to reduced cellular ligase IV activity. Consequently, NHEJ-dependent repair of ionizing-radiation-induced DNA double-strand breaks is compromised in XRCC4 cells. Similarly, immunoglobulin junctional diversification is impaired in cells. However, immunoglobulin levels are normal, and individuals lack overt signs of immunodeficiency. Additionally, in contrast to individuals with LIG4 mutations, pancytopenia leading to bone marrow failure has not been observed. Hence, alterations that alter different NHEJ proteins give rise to a phenotypic spectrum, from SCID to extreme growth failure, with deficiencies in certain key components of this repair pathway predominantly exhibiting growth deficits, reflecting differential developmental requirements for NHEJ proteins to support growth and immune maturation. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Common Variable Immunodeficiency Caused by FANC Mutations.

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Sekinaka, Yujin; Mitsuiki, Noriko; Imai, Kohsuke; Yabe, Miharu; Yabe, Hiromasa; Mitsui-Sekinaka, Kanako; Honma, Kenichi; Takagi, Masatoshi; Arai, Ayako; Yoshida, Kenichi; Okuno, Yusuke; Shiraishi, Yuichi; Chiba, Kenichi; Tanaka, Hiroko; Miyano, Satoru; Muramatsu, Hideki; Kojima, Seiji; Hira, Asuka; Takata, Minoru; Ohara, Osamu; Ogawa, Seishi; Morio, Tomohiro; Nonoyama, Shigeaki

2017-07-01

Common variable immunodeficiency (CVID) is the most common adult-onset primary antibody deficiency disease due to various causative genes. Several genes, which are known to be the cause of different diseases, have recently been reported as the cause of CVID in patients by performing whole exome sequencing (WES) analysis. Here, we found FANC gene mutations as a cause of adult-onset CVID in two patients. B cells were absent and CD4 + T cells were skewed toward CD45RO + memory T cells. T-cell receptor excision circles (TRECs) and signal joint kappa-deleting recombination excision circles (sjKRECs) were undetectable in both patients. Both patients had no anemia, neutropenia, or thrombocytopenia. Using WES, we identified compound heterozygous mutations of FANCE in one patient and homozygous mutation of FANCA in another patient. The impaired function of FANC protein complex was confirmed by a monoubiquitination assay and by chromosome fragility test. We then performed several immunological evaluations including quantitative lymphocyte analysis and TRECs/sjKRECs analysis for 32 individuals with Fanconi anemia (FA). In total, 22 FA patients (68.8%) were found to have immunological abnormalities, suggesting that such immunological findings may be common in FA patients. These data indicate that FANC mutations are involved in impaired lymphogenesis probably by the accumulation of DNA replication stress, leading to CVID. It is important to diagnose FA because it drastically changes clinical management. We propose that FANC mutations can cause isolated immunodeficiency in addition to bone marrow failure and malignancy.

A novel AMELX mutation causes hypoplastic amelogenesis imperfecta.

Science.gov (United States)

Kim, Young-Jae; Kim, Youn Jung; Kang, Jenny; Shin, Teo Jeon; Hyun, Hong-Keun; Lee, Sang-Hoon; Lee, Zang Hee; Kim, Jung-Wook

2017-04-01

Amelogenesis imperfecta (AI) is a hereditary genetic defect affecting tooth enamel. AI is heterogeneous in clinical phenotype as well as in genetic etiology. To date, more than 10 genes have been associated with the etiology of AI. Amelogenin is the most abundant enamel matrix protein, most of which is encoded by the amelogenin gene in the X-chromosome (AMELX). More than 16 alternative splicing transcripts have been identified in the murine Amelx gene. The purpose of this study was to identify the genetic cause of an AI family. We recruited a family with hypoplastic AI and performed mutational analysis on the candidate gene based on the clinical phenotype. Mutational analysis revealed a missense mutation in exon 6 (NM_182680.1; c.242C > T), which changes a sequence in a highly conserved amino acid (NP_872621.1; p.Pro81Leu). Furthermore, a splicing assay using a minigene displayed that the mutation changed the mRNA splicing repertory. In this study, we identified a novel AMELX missense mutation causing hypoplastic AI, and this mutation also resulted in altered mRNA splicing. These results will not only expand the mutation spectrum causing AI but also broaden our understanding of the biological mechanism of enamel formation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genomic mutation study for long-term cells induced by carbon ions

International Nuclear Information System (INIS)

Wang, X.; Furusawa, Y.; Suzuki, M.; Hirayama, R.; Matsumoto, Y.; Qin, Y.

2007-01-01

samples at the HPRT locus was detected to measure 6-thioguanine-resistant colonies. Results: The survival fraction of the cells irradiated by carbon ions was lower than sparsely ionizing (low LET) radiation, and it was also lower in high dose rate (∼1.5Gy/min) than in low dose rate (∼0.008Gy/min) irradiated at the same dose. Furthermore, high dose (D10 dose) induced high mutation fraction. Low dose and low dose rate had the low mutation fractions and different dose rate induced different mutation fraction even at the same dose. Mutation fraction had lower value before 6 days, and the higher level between 12 to 24 days after irradiated, then value went down. Conclusion: The results suggest that high LET radiation may cause higher mutation induction dependent with irradiated dose. Different dose rate also may induce different mutation affection. The heavy ion radiation may cause the long-term genomic mutation and instability of cells. HPRT mutant detection system can be application evaluating the carcinogenic effects of space environmental radiation and heavy ion radiation therapy.

Sun exposure causes somatic second-hit mutations and angiofibroma development in tuberous sclerosis complex

Science.gov (United States)

Tyburczy, Magdalena E.; Wang, Ji-an; Li, Shaowei; Thangapazham, Rajesh; Chekaluk, Yvonne; Moss, Joel; Kwiatkowski, David J.; Darling, Thomas N.

2014-01-01

Tuberous sclerosis complex (TSC) is characterized by the formation of tumors in multiple organs and is caused by germline mutation in one of two tumor suppressor genes, TSC1 and TSC2. As for other tumor suppressor gene syndromes, the mechanism of somatic second-hit events in TSC tumors is unknown. We grew fibroblast-like cells from 29 TSC skin tumors from 22 TSC subjects and identified germline and second-hit mutations in TSC1/TSC2 using next-generation sequencing. Eighteen of 22 (82%) subjects had a mutation identified, and 8 of the 18 (44%) subjects were mosaic with mutant allele frequencies of 0 to 19% in normal tissue DNA. Multiple tumors were available from four patients, and in each case, second-hit mutations in TSC2 were distinct indicating they arose independently. Most remarkably, 7 (50%) of the 14 somatic point mutations were CC>TT ultraviolet ‘signature’ mutations, never seen as a TSC germline mutation. These occurred exclusively in facial angiofibroma tumors from sun-exposed sites. These results implicate UV-induced DNA damage as a cause of second-hit mutations and development of TSC facial angiofibromas and suggest that measures to limit UV exposure in TSC children and adults should reduce the frequency and severity of these lesions. PMID:24271014

CtIP Mutations Cause Seckel and Jawad Syndromes.

Directory of Open Access Journals (Sweden)

Per Qvist

2011-10-01

Full Text Available Seckel syndrome is a recessively inherited dwarfism disorder characterized by microcephaly and a unique head profile. Genetically, it constitutes a heterogeneous condition, with several loci mapped (SCKL1-5 but only three disease genes identified: the ATR, CENPJ, and CEP152 genes that control cellular responses to DNA damage. We previously mapped a Seckel syndrome locus to chromosome 18p11.31-q11.2 (SCKL2. Here, we report two mutations in the CtIP (RBBP8 gene within this locus that result in expression of C-terminally truncated forms of CtIP. We propose that these mutations are the molecular cause of the disease observed in the previously described SCKL2 family and in an additional unrelated family diagnosed with a similar form of congenital microcephaly termed Jawad syndrome. While an exonic frameshift mutation was found in the Jawad family, the SCKL2 family carries a splicing mutation that yields a dominant-negative form of CtIP. Further characterization of cell lines derived from the SCKL2 family revealed defective DNA damage induced formation of single-stranded DNA, a critical co-factor for ATR activation. Accordingly, SCKL2 cells present a lowered apoptopic threshold and hypersensitivity to DNA damage. Notably, over-expression of a comparable truncated CtIP variant in non-Seckel cells recapitulates SCKL2 cellular phenotypes in a dose-dependent manner. This work thus identifies CtIP as a disease gene for Seckel and Jawad syndromes and defines a new type of genetic disease mechanism in which a dominant negative mutation yields a recessively inherited disorder.

DNA methylation in the pathophysiology of hyperphenylalaninemia in the PAH(enu2) mouse model of phenylketonuria.

Science.gov (United States)

Dobrowolski, S F; Lyons-Weiler, J; Spridik, K; Vockley, J; Skvorak, K; Biery, A

2016-09-01

Phenylalanine hydroxylase deficient phenylketonuria (PKU) is the paradigm for a treatable inborn error of metabolism where maintaining plasma phenylalanine (Phe) in the therapeutic range relates to improved clinical outcomes. While Phe is the presumed intoxicating analyte causal in neurologic damage, the mechanism(s) of Phe toxicity has remained elusive. Altered DNA methylation is a recognized response associated with exposure to numerous small molecule toxic agents. Paralleling this effect, we hypothesized that chronic Phe over-exposure in the brain would lead to aberrant DNA methylation with secondary influence upon gene regulation that would ultimately contribute to PKU neuropathology. The PAH(enu2) mouse models human PKU with intrinsic hyperphenylalaninemia, abnormal response to Phe challenge, and neurologic deficit. To examine this hypothesis, we assessed DNA methylation patterns in brain tissues using methylated DNA immunoprecipitation and paired end sequencing in adult PAH(enu2) animals maintained under either continuous dietary Phe restriction or chronic hyperphenylalaninemia. Heterozygous PAH(enu2/WT) litter mates served as controls for normal Phe exposure. Extensive repatterning of DNA methylation was observed in brain tissue of hyperphenylalaninemic animals while Phe restricted animals displayed an attenuated pattern of aberrant DNA methylation. Affected gene coding regions displayed aberrant hypermethylation and hypomethylation. Gene body methylation of noncoding RNA genes was observed and among these microRNA genes were prominent. Of particular note, observed only in hyperphenylalaninemic animals, was hypomethylation of miRNA genes within the imprinted Dlk1-Dio3 locus on chromosome 12. Aberrant methylation of microRNA genes influenced their expression which has secondary effects upon the expression of targeted protein coding genes. Differential hypermethylation of gene promoters was exclusive to hyperphenylalaninemic PAH(enu2) animals. Genes with

Measurement of the Absolute Branching Fraction for Lambda(+)(c) -> Lambda e(+)nu(e)

NARCIS (Netherlands)

Ablikim, M.; Achasov, M.N.; Ai, X.C.; Albayrak, O.; Albrecht, M.; Ambrose, D.J.; Amorose, A.; Haddadi, Z.; Kalantar-Nayestanaki, Nasser; Kavatsyuk, M.; Messchendorp, J.G; Tiemens, M.

2015-01-01

We report the first measurement of the absolute branching fraction for Lambda(+)(c) -> Lambda e(+)nu(e). This measurement is based on 567 pb(-1) of e(+)e(-) annihilation data produced at root s = 4.599 GeV, which is just above the Lambda(+)(c)Lambda(-)(c) threshold. The data were collected with the

Inflammation, gene mutation and photoimmunosuppression in response to UVR-induced oxidative damage contributes to photocarcinogenesis

Energy Technology Data Exchange (ETDEWEB)

Halliday, Gary M. [Dermatology Research Laboratories, Division of Medicine, Melanoma and Skin Cancer Research Institute, Royal Prince Alfred Hospital at the University of Sydney, Sydney, NSW (Australia)]. E-mail: garyh@med.usyd.edu.au

2005-04-01

Ultraviolet (UV) radiation causes inflammation, gene mutation and immunosuppression in the skin. These biological changes are responsible for photocarcinogenesis. UV radiation in sunlight is divided into two wavebands, UVB and UVA, both of which contribute to these biological changes, and therefore probably to skin cancer in humans and animal models. Oxidative damage caused by UV contributes to inflammation, gene mutation and immunosuppression. This article reviews evidence for the hypothesis that UV oxidative damage to these processes contributes to photocarcinogenesis. UVA makes a larger impact on oxidative stress in the skin than UVB by inducing reactive oxygen and nitrogen species which damage DNA, protein and lipids and which also lead to NAD+ depletion, and therefore energy loss from the cell. Lipid peroxidation induces prostaglandin production that in association with UV-induced nitric oxide production causes inflammation. Inflammation drives benign human solar keratosis (SK) to undergo malignant conversion into squamous cell carcinoma (SCC) probably because the inflammatory cells produce reactive oxygen species, thus increasing oxidative damage to DNA and the immune system. Reactive oxygen or nitrogen appears to cause the increase in mutational burden as SK progress into SCC in humans. UVA is particularly important in causing immunosuppression in both humans and mice, and UV lipid peroxidation induced prostaglandin production and UV activation of nitric oxide synthase is important mediators of this event. Other immunosuppressive events are likely to be initiated by UV oxidative stress. Antioxidants have also been shown to reduce photocarcinogenesis. While most of this evidence comes from studies in mice, there is supporting evidence in humans that UV-induced oxidative damage contributes to inflammation, gene mutation and immunosuppression. Available evidence implicates oxidative damage as an important contributor to sunlight-induced carcinogenesis in humans.

Inflammation, gene mutation and photoimmunosuppression in response to UVR-induced oxidative damage contributes to photocarcinogenesis

International Nuclear Information System (INIS)

Halliday, Gary M.

2005-01-01

Ultraviolet (UV) radiation causes inflammation, gene mutation and immunosuppression in the skin. These biological changes are responsible for photocarcinogenesis. UV radiation in sunlight is divided into two wavebands, UVB and UVA, both of which contribute to these biological changes, and therefore probably to skin cancer in humans and animal models. Oxidative damage caused by UV contributes to inflammation, gene mutation and immunosuppression. This article reviews evidence for the hypothesis that UV oxidative damage to these processes contributes to photocarcinogenesis. UVA makes a larger impact on oxidative stress in the skin than UVB by inducing reactive oxygen and nitrogen species which damage DNA, protein and lipids and which also lead to NAD+ depletion, and therefore energy loss from the cell. Lipid peroxidation induces prostaglandin production that in association with UV-induced nitric oxide production causes inflammation. Inflammation drives benign human solar keratosis (SK) to undergo malignant conversion into squamous cell carcinoma (SCC) probably because the inflammatory cells produce reactive oxygen species, thus increasing oxidative damage to DNA and the immune system. Reactive oxygen or nitrogen appears to cause the increase in mutational burden as SK progress into SCC in humans. UVA is particularly important in causing immunosuppression in both humans and mice, and UV lipid peroxidation induced prostaglandin production and UV activation of nitric oxide synthase is important mediators of this event. Other immunosuppressive events are likely to be initiated by UV oxidative stress. Antioxidants have also been shown to reduce photocarcinogenesis. While most of this evidence comes from studies in mice, there is supporting evidence in humans that UV-induced oxidative damage contributes to inflammation, gene mutation and immunosuppression. Available evidence implicates oxidative damage as an important contributor to sunlight-induced carcinogenesis in humans

Radiation-induced dominant skeletal mutations in mice

International Nuclear Information System (INIS)

Selby, P.B.

1979-01-01

Skeletons were chosen for the attempt to determine the overall damage by radiation to one body system largely bacause they can be prepared readily for detailed study. Dominant mutations were of special interest because they are the type of mutations that would account for almost all damage induced in the early generations. The male offsprings derived from spermatogonial irradiation were used in the mutation-rate experiment, and the mutation frequency of 1.4% per gamete was found. The general dominant skeletal mutations are 1) the fusions of bones or other changes in individual bones, 2) the gross changes in bone shapes, usually caused by incomplete or too extensive bone growth, or 3) the shifts in the relative positions of bones. The recessive lethality in the period between implantation and birth can be recognized by the expected high death rate of implants in approximately 1/4 of the crosses that are between heterozygotes for a given mutation. The recessive lethal mutations may account for an important fraction of human genetic disorders owing to their dominant deleterious effects which represent only a small fraction, but because of their easy detection, they have been studied more than other dominants. At least 45, or 27%, of 164 dominant visibles in mice, ignoring those concerned with enzyme polymorphisms and immunological traits, appear to be recessive lethals. (Yamashita, S.)

Induced mutations in sesame breeding

International Nuclear Information System (INIS)

Ashri, A.

2001-01-01

The scope of induced mutations in sesame (Sesamum indicum L.) breeding is reviewed. So far in Egypt, India, Iraq, Rep. of Korea, and Sri Lanka, 14 officially released varieties have been developed through induced mutations: 12 directly and 2 through cross breeding (one using the 'dt45' induced mutant from Israel). For another variety released in China there are no details. The induced mutations approach was adopted primarily in order to obtain genetic variability that was not available in the germplasm collection. The mutagens commonly applied have been gamma rays, EMS and sodium azide. Sesame seeds can withstand high mutagen doses, and there are genotypic differences in sensitivity between varieties. The mutants induced in the above named countries and others include better yield, improved seed retention, determinate habit, modified plant architecture and size, more uniform and shorter maturation period, earliness, resistance to diseases, genic male sterility, seed coat color, higher oil content and modified fatty acids composition. Some of the induced mutants have already given rise to improved varieties, the breeding value of other mutants is now being assessed and still others can serve as useful markers in genetic studies and breeding programmes. (author)

Induced pluripotent stem cells (iPSCs) derived from a patient with frontotemporal dementia caused by a R406W mutation in microtubule-associated protein tau (MAPT)

DEFF Research Database (Denmark)

Rasmussen, Mikkel A.; Hjermind, Lena E.; Hasholt, Lis F.

2016-01-01

Skin fibroblasts were obtained from a 59-year-old woman diagnosed with frontotemporal dementia. The disease is caused by a R406W mutation in microtubule-associated protein tau (MAPT). Induced pluripotent stem cells (iPSCs) were established by electroporation with episomal plasmids containing hOCT4...

Induced mutation of Dendrobium orchid

International Nuclear Information System (INIS)

Sakinah Ariffin; Mohd Nazir Basiran

2000-01-01

Dendrobiiim orchids serve as the main orchid cut flower export of Malaysia. The wide range of colour and forms presently available in the market are obtained through hybridisation. Induced mutation breeding program was initiated on a commercial variety Dendrobium 'Sonia Kai' to explore the possibilities of obtaining new colour and forms. Matured seeds from self pollination were cultured and irradiated at 35 Gy at the protocorm-like bodies (PLBS) stage. Selection of induced mutations was done after the first flowering of the plants regenerated from the irradiated protocorms. Results showed changes in flower colour, shape and size. Most of these chances are expressed in different combinations in the petals, sepals and lip of the flowers. Thus, resulting. in a very wide spectrum of mutations. Some of these chances are not stable. To date, mutants that showed stable characteristics changes are grouped into 11 categories based on flower colour and form. These results show that the combination of its vitro technique and induced mutation can be applied in orchid breeding to produce new interesting and attractive variety for the market

The relationship between reaction kinetics and mutagenic action of monofunctional alkylating agents in higher eukaryotic systems. IV. The effects of the excision-defective mei-9L1 and mus(2)201D1 mutants on alkylation-induced genetic damage in Drosophila.

Science.gov (United States)

Vogel, E W; Dusenbery, R L; Smith, P D

1985-04-01

Repair-defective mutants of Drosophila melanogaster which identify two major DNA excision repair loci have been examined for their effects on alkylation-induced mutagenesis using the sex-linked recessive lethal assay as a measure of genotoxic endpoint. The alkylating agents (AAs) chosen for comparative analysis were selected on the basis of their reaction kinetics with DNA and included MMS, EMS, MNU, DMN, ENU, DEN and ENNG. Repair-proficient males were treated with the AAs and mated with either excision-defective mei-9L1 or mus(2)201D1 females or appropriate excision-proficient control females. The results of the present work suggest that a qualitative and quantitative relationship exists between the nature and the extent of chemical modification of DNA and the induction of of genetic alterations. The presence of either excision-defective mutant can enhance the frequency of mutation (hypermutability) and this hypermutability can be correlated with the Swain-Scott constant S of specific AAs such that as the SN1 character of the DNA alkylation reaction increases, the difference in response between repair-deficient and repair-proficient females decreases. The order of hypermutability of AAs with mei-9L1 relative to mei-9+ is MMS greater than MNU greater than DMN = EMS greater than iPMS = ENU = DEN = ENNG. When the percentage of lethal mutations induced in mei-9L1 females are plotted against those determined for control females, straight lines of different slopes are obtained. These mei-9L1/mei-9+ indices are: MMS = 7.6, MNU = 5.4, DMN = 2.4, EMS = 2.4 and iPMS = ENU = DEN = ENNG = 1. An identical order of hypermutability with similar indices is obtained for the mus(2)201 mutants: MMS(7.3) greater than MNU (5.4) greater than EMS(2.0) greater than ENU(1.1). Thus, absence of excision repair function has a significant effect on mutation production by AAs efficient in alkylating N-atoms in DNA but no measurable influence on mutation production by AAs most efficient in

Mutagenic effect of radionuclides incorporated into DNA of Drosophila melanogaster. Progress report, December 15, 1982-July 15, 1983

International Nuclear Information System (INIS)

Lee, W.R.

1983-01-01

The molecular changes in DNA of mutations induced at the well-defined locus alcohol dehydrogenase (Adh) in Drosophila melanogaster were compared between null mutants induced by x-rays, the alkylating agent N-ethyl-N-nitrosourea (ENU) and decay of tritium incorporated into specific sites of DNA

Heterozygous ABCC8 mutations are a cause of MODY.

Science.gov (United States)

Bowman, P; Flanagan, S E; Edghill, E L; Damhuis, A; Shepherd, M H; Paisey, R; Hattersley, A T; Ellard, S

2012-01-01

The ABCC8 gene encodes the sulfonylurea receptor 1 (SUR1) subunit of the pancreatic beta cell ATP-sensitive potassium (K(ATP)) channel. Inactivating mutations cause congenital hyperinsulinism (CHI) and activating mutations cause transient neonatal diabetes (TNDM) or permanent neonatal diabetes (PNDM) that can usually be treated with sulfonylureas. Sulfonylurea sensitivity is also a feature of HNF1A and HNF4A MODY, but patients referred for genetic testing with clinical features of these types of diabetes do not always have mutations in the HNF1A/4A genes. Our aim was to establish whether mutations in the ABCC8 gene cause MODY that is responsive to sulfonylurea therapy. We sequenced the ABCC8 gene in 85 patients with a BMI MODY criteria, with two diagnosed after 25 years and one patient, who had no family history of diabetes, as a result of a proven de novo mutation. ABCC8 mutations can cause MODY in patients whose clinical features are similar to those with HNF1A/4A MODY. Therefore, sequencing of ABCC8 in addition to the known MODY genes should be considered if such features are present, to facilitate optimal clinical management of these patients.

Indian hedgehog mutations causing brachydactyly type A1 impair Hedgehog signal transduction at multiple levels

Science.gov (United States)

Ma, Gang; Yu, Jiang; Xiao, Yue; Chan, Danny; Gao, Bo; Hu, Jianxin; He, Yongxing; Guo, Shengzhen; Zhou, Jian; Zhang, Lingling; Gao, Linghan; Zhang, Wenjuan; Kang, Yan; Cheah, Kathryn SE; Feng, Guoyin; Guo, Xizhi; Wang, Yujiong; Zhou, Cong-zhao; He, Lin

2011-01-01

Brachydactyly type A1 (BDA1), the first recorded Mendelian autosomal dominant disorder in humans, is characterized by a shortening or absence of the middle phalanges. Heterozygous missense mutations in the Indian Hedgehog (IHH) gene have been identified as a cause of BDA1; however, the biochemical consequences of these mutations are unclear. In this paper, we analyzed three BDA1 mutations (E95K, D100E, and E131K) in the N-terminal fragment of Indian Hedgehog (IhhN). Structural analysis showed that the E95K mutation changes a negatively charged area to a positively charged area in a calcium-binding groove, and that the D100E mutation changes the local tertiary structure. Furthermore, we showed that the E95K and D100E mutations led to a temperature-sensitive and calcium-dependent instability of IhhN, which might contribute to an enhanced intracellular degradation of the mutant proteins via the lysosome. Notably, all three mutations affected Hh binding to the receptor Patched1 (PTC1), reducing its capacity to induce cellular differentiation. We propose that these are common features of the mutations that cause BDA1, affecting the Hh tertiary structure, intracellular fate, binding to the receptor/partners, and binding to extracellular components. The combination of these features alters signaling capacity and range, but the impact is likely to be variable and mutation-dependent. The potential variation in the signaling range is characterized by an enhanced interaction with heparan sulfate for IHH with the E95K mutation, but not the E131K mutation. Taken together, our results suggest that these IHH mutations affect Hh signaling at multiple levels, causing abnormal bone development and abnormal digit formation. PMID:21537345

Hypomorphic mutation in mouse Nppc gene causes retarded bone growth due to impaired endochondral ossification

International Nuclear Information System (INIS)

Tsuji, Takehito; Kondo, Eri; Yasoda, Akihiro; Inamoto, Masataka; Kiyosu, Chiyo; Nakao, Kazuwa; Kunieda, Tetsuo

2008-01-01

Long bone abnormality (lbab/lbab) is a spontaneous mutant mouse characterized by dwarfism with shorter long bones. A missense mutation was reported in the Nppc gene, which encodes C-type natriuretic peptide (CNP), but it has not been confirmed whether this mutation is responsible for the dwarf phenotype. To verify that the mutation causes the dwarfism of lbab/lbab mice, we first investigated the effect of CNP in lbab/lbab mice. By transgenic rescue with chondrocyte-specific expression of CNP, the dwarf phenotype in lbab/lbab mice was completely compensated. Next, we revealed that CNP derived from the lbab allele retained only slight activity to induce cGMP production through its receptor. Histological analysis showed that both proliferative and hypertrophic zones of chondrocytes in the growth plate of lbab/lbab mice were markedly reduced. Our results demonstrate that lbab/lbab mice have a hypomorphic mutation in the Nppc gene that is responsible for dwarfism caused by impaired endochondral ossification

Induced pluripotent stem cells (iPSCs) derived from af pre-symptomatic carrier of a R406W mutation in microtubule-associated protein tau (MAPT) causing frontotemporal dementia

DEFF Research Database (Denmark)

Rasmussen, Mikkel A.; Hjermind, Lena Elisabeth; Hasholt, Lis Frydenreich

2016-01-01

Skin fibroblasts were obtained from a 28-year-old pre-symptomatic woman carrying a R406W mutation in microtubule-associated protein tau (MAPT), known to cause frontotemporal dementia. Induced pluripotent stem cell (iPSCs) were established by electroporation with episomal plasmids containing hOCT4...

Chloroplast mutations induced by 9-aminoacridine hydrochloride are independent of the plastome mutator in Oenothera.

Science.gov (United States)

GuhaMajumdar, M; Baldwin, S; Sears, B B

2004-02-01

Oenothera plants homozygous for the recessive plastome mutator allele ( pm) show chloroplast DNA (cpDNA) mutation frequencies that are about 1,000-fold higher than spontaneous levels. The pm-encoded gene product has been hypothesized to have a function in cpDNA replication, repair and/or mutation avoidance. Previous chemical mutagenesis experiments with the alkylating agent nitroso-methyl urea (NMU) showed a synergistic effect of NMU on the induction of mutations in the pm line, suggesting an interaction between the pm-encoded gene product and one of the repair systems that corrects alkylation damage. The goal of the experiments described here was to examine whether the pm activity extends to the repair of damage caused by non-alkylating mutagens. To this end, the intercalating mutagen, 9-aminoacridine hydrochloride (9AA) was tested for synergism with the plastome mutator. A statistical analysis of the data reported here indicates that the pm-encoded gene product is not involved in the repair of the 9AA-induced mutations. However, the recovery of chlorotic sectors in plants derived from the mutagenized seeds shows that 9AA can act as a mutagen of the chloroplast genome.

Search for the weak decays J/psi -> D-s(()*()-) e(+)nu(e) + c.c.

NARCIS (Netherlands)

Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Ferroli, R. Baldini; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Chu, Y. P.; Cibinetto, G.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; De Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fu, C. D.; Gao, Q.; Gao, Y.; Garzia, I.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, T.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S; Han, Y. L.; Harris, F. A.; He, K. L.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. M.; Huang, G. S.; Huang, H. P.; Huang, J. S.; Huang, X. T.; Huang, Y.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. L.; Jiang, L. W.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kuehn, W.; Kupsc, A.; Lai, W.; Lange, J. S.; Lara, M.; Larin, P.; Li, C. H.; Li, Cheng; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, P. R.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. M.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, R. Q.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. N.; Ma, X. Y.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Moeini, H.; Morales, C. Morales; Moriya, K.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pu, Y. N.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ren, H. L.; Ripka, M.; Rong, G.; Ruan, X. D.; Santoro, V.; Sarantsev, A.; Savrie, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Spruck, B.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Toth, D.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q. J.; Wang, S. G.; Wang, W.; Wang, X. F.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, Z.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. X.; Yang, L.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, H. W.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. H.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, Li; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.

2014-01-01

Using a sample of 2.25 x 10(8) J/psi events collected with the BESIII detector at the BEPCII collider, we search for the J/psi semileptonic weak decay J/psi -> D-s(-) e(+)nu(e) +c.c. with a much higher sensitivity than previous searches. We also perform the first search for J/psi -> D-s(*-) e(+)

Mutations in the evolutionarily highly conserved KEOPS complex genes cause nephrotic syndrome with microcephaly

Science.gov (United States)

Braun, Daniela A.; Rao, Jia; Mollet, Geraldine; Schapiro, David; Daugeron, Marie-Claire; Tan, Weizhen; Gribouval, Olivier; Boyer, Olivia; Revy, Patrick; Jobst-Schwan, Tilman; Schmidt, Johanna Magdalena; Lawson, Jennifer A.; Schanze, Denny; Ashraf, Shazia; Boddaert, Nathalie; Collinet, Bruno; Martin, Gaëlle; Liger, Dominique; Lovric, Svjetlana; Furlano, Monica; Guerrera, I. Chiara; Sanchez-Ferras, Oraly; Menten, Björn; Vergult, Sarah; De Rocker, Nina; Airik, Merlin; Hermle, Tobias; Shril, Shirlee; Widmeier, Eugen; Gee, Heon Yung; Choi, Won-Il; Sadowski, Carolin E.; Pabst, Werner L.; Warejko, Jillian; Daga, Ankana; LeBerre, Tamara Basta; Matejas, Verena; Behnam, Babak; Beeson, Brendan; Begtrup, Amber; Bruce, Malcolm; Ch'ng, Gaik-Siew; Lin, Shuan-Pei; Chang, Jui-Hsing; Chen, Chao-Huei; Cho, Megan T.; Gipson, Patrick E.; Hsu, Chyong-Hsin; Kari, Jameela A.; Ke, Yu-Yuan; Kiraly-Borri, Cathy; Lai, Wai-ming; Lemyre, Emmanuelle; Littlejohn, Rebecca Okasha; Masri, Amira; Moghtaderi, Mastaneh; Nakamura, Kazuyuki; Praet, Marleen; Prasad, Chitra; Prytula, Agnieszka; Roeder, Elizabeth; Rump, Patrick; Schnur, Rhonda E.; Shiihara, Takashi; Sinha, Manish; Soliman, Neveen A; Soulami, Kenza; Sweetser, David A.; Tsai, Wen-Hui; Tsai, Jeng-Daw; Vester, Udo; Viskochil, David H.; Vatanavicharn, Nithiwat; Waxler, Jessica L.; Wolf, Matthias T.F.; Wong, Sik-Nin; Poduri, Annapurna; Truglio, Gessica; Mane, Shrikant; Lifton, Richard P.; Bouchard, Maxime; Kannu, Peter; Chitayat, David; Magen, Daniella; Calleweart, Bert; van Tilbeurgh, Herman; Zenker, Martin; Antignac, Corinne; Hildebrandt, Friedhelm

2018-01-01

Galloway-Mowat syndrome (GAMOS) is a severe autosomal-recessive disease characterized by the combination of early-onset steroid-resistant nephrotic syndrome (SRNS) and microcephaly with brain anomalies. To date, mutations of WDR73 are the only known monogenic cause of GAMOS and in most affected individuals the molecular diagnosis remains elusive. We here identify recessive mutations of OSGEP, TP53RK, TPRKB, or LAGE3, encoding the 4 subunits of the KEOPS complex in 33 individuals of 30 families with GAMOS. CRISPR/Cas9 knockout in zebrafish and mice recapitulates the human phenotype of microcephaly and results in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibits cell proliferation, which human mutations fail to rescue, and knockdown of either gene activates DNA damage response signaling and induces apoptosis. OSGEP and TP53RK molecularly interact and co-localize with the actin-regulating ARP2/3 complex. Furthermore, knockdown of OSGEP and TP53RK induces defects of the actin cytoskeleton and reduces migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identify 4 novel monogenic causes of GAMOS, describe the first link between KEOPS function and human disease, and delineate potential pathogenic mechanisms. PMID:28805828

Molecular and genetic characterization of a radiation-induced structural rearrangement in mouse chromosome 2 causing mutations at the limb deformity and agouti loci

International Nuclear Information System (INIS)

Woychik, R.P.; Generoso, W.M.; Russell, L.B.; Cain, K.T.; Cacheiro, N.L.; Bultman, S.J.; Selby, P.B.; Dickinson, M.E.; Hogan, B.L.

1990-01-01

Molecular characterization of mutations in the mouse, particularly those involving agent-induced major structural alterations, is proving to be useful for correlating the structure and expression of individual genes with their function in the whole organism. Here we present the characterization of a radiation-induced mutation that simultaneously generated distinct alleles of both the limb deformity (ld) and agouti (a) loci, two developmentally important regions of chromosome 2 normally separated by 20 centimorgans. Cytogenetic analysis revealed that an interstitial segment of chromosome 17 (17B- 17C; or, possibly, 17A2-17B) had been translocated into the distal end of chromosome 2, resulting in a smaller-than-normal chromosome 17 (designated 17del) and a larger form of chromosome 2 designated 2(17). Additionally, a large interstitial segment of the 2(17) chromosome, immediately adjacent and proximal to the insertion site, did not match bands 2E4-2H1 at corresponding positions on a normal chromosome 2. Molecular analysis detected a DNA rearrangement in which a portion of the ld locus was joined to sequences normally tightly linked to the a locus. This result, along with the genetic and cytogenetic data, suggests that the alleles of ld and a in this radiation-induced mutation, designated ldIn2 and ajIn2, were associated with DNA breaks caused by an inversion of an interstitial segment in the 2(17) chromosome

Detection of new MHC mutations in mice by skin grafting, tumor transplantation and monoclonal antibodies: a comparison

International Nuclear Information System (INIS)

Egorov, I.K.; Egorov, O.S.

1988-01-01

Two mechanisms of major histocompatibility complex (MHC) mutations have been described in mice: gene conversion and homologous but unequal recombination. However, the knowledge of mutations in MHC is incomplete because studies have been limited almost exclusively to two haplotypes, H-2/sup b/ and H-2/sup d/, while hundreds of haplotypes exist in nature; it has been biased by the use of only one procedure of screening for mutation, skin grafting. The authors used three procedures to screen for MHC mutations: (1) conventional techniques of skin grafting, (2) syngeneic tumor transplantation and (3) typing with monoclonal anti-MHC antibodies (mAbs) and complement. The faster technique of tumor transplantation detected mutants similar to those discovered by skin grafting technique. Screening with mAbs allowed us to detect both mutants that are capable of rejecting standard skin grafts and those that are silent in skin grafting tests, and which therefore resulted in a higher apparent mutation frequency. Two mutants of the H-2/sup a/ haplotype were found that carry concomitant class I and class II antigenic alterations. Both MHC mutants silent in skin grafting tests and mutants carrying concomitant class I and class II alterations have never been studied before and are expected to reveal new mechanisms of generating MHC mutations. 1-Ethyl-1-nitrosourea (ENU) failed to induce de novo MHC mutations in our skin grafting series

Induced pluripotent stem cells (iPSCs) derived from a symptomatic carrier of a S305I mutation in the microtubule-associated protein tau (MAPT)-gene causing frontotemporal dementia

DEFF Research Database (Denmark)

Nimsanor, Natakarn; Jørring, Ida; Rasmussen, Mikkel A.

2016-01-01

Frontotemporal dementia with parkinsonism linked to chromosome 17q21.2 (FTDP-17) is an autosomal-dominant neurodegenerative disorder. Mutations in the gene coding the microtubule-associated protein tau (MAPT) can cause FTDP-17 but the underlying mechanisms of the disease are still unknown. Induced...

Radiation induced chlorophyll mutations in rice

International Nuclear Information System (INIS)

Bari, G.; Mustafa, G.; Soomro, A.M.; Baloch, A.W.

1985-01-01

Air dried grains of four local varieties of rice were treated with gamma-rays and fast neutrons for determining their mutagenic effectiveness through the occurence of chlorophyll mutations. Fast neutrons were more effective in inducing chlorophyll mutations and the rice variety Basmati 370 produced maximum number of mutations followed by varieties Sonahri Sugdasi, Jajai 77 and Sada Gulab. The highest frequency of chlorophyll mutations was that of albina types followed by striata types. The xantha, viridis and tigrina types of mutations were less frequent. (authors)

N114S mutation causes loss of ATP-induced aggregation of human phosphoribosylpyrophosphate synthetase 1

International Nuclear Information System (INIS)

Liu Honglin; Peng, Xiaohui; Zhao Fang; Zhang Guobin; Tao Ye; Luo Zhaofeng; Li Yang; Teng Maikun; Li Xu; Wei Shiqiang

2009-01-01

This study examined recombinant wild-type human phosphoribosylpyrophosphate synthetase 1 (wt-PRS1, EC 2.7.6.1) and the point mutant Asn114Ser PRS1 (N114S-Mutant) in cells of a patient with primary gout. Dynamic light-scattering and sedimentation velocity experiments indicated that the monomeric wt-PRS1 in solution was assembled into hexamers after adding the substrate ATP. However, this ATP-induced aggregation effect was not observed with N114S-Mutant, which has a 50% higher enzymatic activity than that of wt-PRS1. Synchrotron radiation circular dichroism spectroscopy revealed that the point mutation causes an increase of α-helix content and a decrease of turn content. Examination of the crystal structure of wt-PRS1 indicated that 12 hydrogen bonds formed by 6 pairs of N114 and D139 have an important role in stabilizing the hexamer. We suggest that the substitution of S114 for N114 in N114S-Mutant leads to the rupture of 12 hydrogen bonds and breakage of the PO 4 3- allosteric site where PO 4 3- functions as a fixer of the ATP-binding loop. Therefore, we consider that formation of the hexamer as the structural basis of the ADP allosteric inhibition is greatly weakened by the N114S mutation, and that alteration of the ATP-binding loop conformation is the key factor in the increased activity of N114S-Mutant. These two factors could be responsible for the high level of activity of N114S-Mutant in this patient.

A switch from high-fidelity to error-prone DNA double-strand break repair underlies stress-induced mutation.

Science.gov (United States)

Ponder, Rebecca G; Fonville, Natalie C; Rosenberg, Susan M

2005-09-16

Special mechanisms of mutation are induced in microbes under growth-limiting stress causing genetic instability, including occasional adaptive mutations that may speed evolution. Both the mutation mechanisms and their control by stress have remained elusive. We provide evidence that the molecular basis for stress-induced mutagenesis in an E. coli model is error-prone DNA double-strand break repair (DSBR). I-SceI-endonuclease-induced DSBs strongly activate stress-induced mutations near the DSB, but not globally. The same proteins are required as for cells without induced DSBs: DSBR proteins, DinB-error-prone polymerase, and the RpoS starvation-stress-response regulator. Mutation is promoted by homology between cut and uncut DNA molecules, supporting a homology-mediated DSBR mechanism. DSBs also promote gene amplification. Finally, DSBs activate mutation only during stationary phase/starvation but will during exponential growth if RpoS is expressed. Our findings reveal an RpoS-controlled switch from high-fidelity to mutagenic DSBR under stress. This limits genetic instability both in time and to localized genome regions, potentially important evolutionary strategies.

New mutations affecting induced mutagenesis in yeast.

Science.gov (United States)

Lawrence, C W; Krauss, B R; Christensen, R B

1985-01-01

Previously isolated mutations in baker's yeast, Saccharomyces cerevisiae, that impair induced mutagenesis were all identified with the aid of tests that either exclusively or predominantly detect base-pair substitutions. To avoid this bias, we have screened 11 366 potentially mutant clones for UV-induced reversion of the frameshift allele, his4-38, and have identified 10 mutants that give much reduced yields of revertants. Complementation and recombination tests show that 6 of these carry mutations at the previously known REV1, REV1 and REV3 loci, while the remaining 4 define 3 new genes, REV4 (2 mutations), REV5 and REV6. The rev4 mutations are readily suppressed in many genetic backgrounds and, like the rev5 mutation, impart only a limited deficiency for induced mutagenesis: it is likely, therefore that the REV4+ and REV5+ gene functions are only remotely concerned with this process. The rev6 mutants have a more general deficiency, however, as well as marked sensitivity to UV and an increased spontaneous mutation rate, properties that suggest the REV6 gene is directly involved in mutation induction. The REV5 gene is located about 1 cM proximal to CYC1 on chromosome X.

Genes and Mutations Causing Autosomal Dominant Retinitis Pigmentosa

Science.gov (United States)

Daiger, Stephen P.; Bowne, Sara J.; Sullivan, Lori S.

2015-01-01

Retinitis pigmentosa (RP) has a prevalence of approximately one in 4000; 25%–30% of these cases are autosomal dominant retinitis pigmentosa (adRP). Like other forms of inherited retinal disease, adRP is exceptionally heterogeneous. Mutations in more than 25 genes are known to cause adRP, more than 1000 mutations have been reported in these genes, clinical findings are highly variable, and there is considerable overlap with other types of inherited disease. Currently, it is possible to detect disease-causing mutations in 50%–75% of adRP families in select populations. Genetic diagnosis of adRP has advantages over other forms of RP because segregation of disease in families is a useful tool for identifying and confirming potentially pathogenic variants, but there are disadvantages too. In addition to identifying the cause of disease in the remaining 25% of adRP families, a central challenge is reconciling clinical diagnosis, family history, and molecular findings in patients and families. PMID:25304133

Frontotemporal dementia caused by CHMP2B mutations

DEFF Research Database (Denmark)

Isaacs, A M; Johannsen, P; Holm, I

2011-01-01

CHMP2B mutations are a rare cause of autosomal dominant frontotemporal dementia (FTD). The best studied example is frontotemporal dementia linked to chromosome 3 (FTD-3) which occurs in a large Danish family, with a further CHMP2B mutation identified in an unrelated Belgian familial FTD patient. ...

Reversal or protection by light of the ethidium bromide induced petite mutation in yeast

International Nuclear Information System (INIS)

Hixon, S.C.; Burnham, A.D.; Irons, R.L.

1979-01-01

An intermediate in the ethidium bromide (EB) induced petite mutation pathway may be destabilized by daylight light to cause a reversion to the normal grande phenotype. Starved cells preincubated in the dark for up to 6 h with 100μg/ml EB could be reverted to grandes after one hour of light exposure, whereas similarly treated cells maintained in the dark expresse the petite mutation in more than 80 percent of the population. In addition, the production of petite mutants by EB in buffer could be prevented if cell suspensions were exposed to light immediately upon the addition of EB. Photoreversal of the EB-derived petite mutation in growing cells as less efficient presumably because the availability of an energy source caused a continuation of mutation events beyond the light revertible step to a non-reversible fixation of the mutation. Cells treated with EB in growth and reversal of the mutation. This may be due to the cold inhibition of an enzyme which comes into play beyond the light sensitive step in the mutation pathway. (orig.) [de

Germline KRAS mutations cause Noonan syndrome.

NARCIS (Netherlands)

Schubbert, S.; Zenker, M.; Rowe, S.L.; Boll, S.; Klein, C.; Bollag, G.; Burgt, I. van der; Musante, L.; Kalscheuer, V.M.M.; Wehner, L.E.; Nguyen, H.; West, B.; Zhang, K.Y.; Sistermans, E.A.; Rauch, A.; Niemeyer, C.M.; Shannon, K.; Kratz, C.P.

2006-01-01

Noonan syndrome (MIM 163950) is characterized by short stature, facial dysmorphism and cardiac defects. Heterozygous mutations in PTPN11, which encodes SHP-2, cause approximately 50% of cases of Noonan syndrome. The SHP-2 phosphatase relays signals from activated receptor complexes to downstream

KITLG Mutations Cause Familial Progressive Hyper- and Hypopigmentation

DEFF Research Database (Denmark)

Amyere, Mustapha; Vogt, Thomas; Hoo, Joe

2011-01-01

by familial café-au-lait spots and skin fold freckling, caused by mutations in SPRED1. We performed a genome-wide linkage analysis in seven families with FPHH, and identified linkage on 12q21.12-q22, which overlaps with the DUH2 locus. We investigated whether KITLG in the locus is mutated in FPHH. We......Familial progressive hyper- and hypopigmentation (FPHH) is thought to be an autosomal dominant disorder with reduced penetrance. Clinical signs consist of progressive diffuse, partly blotchy hyperpigmented lesions, multiple café-au-lait spots, intermingled with scattered hypopigmented......-strand in KITLG, suggesting its important role in the activation of the KITLG receptor c-Kit. In aggregate, mutations in a single gene cause various pigmentation disorders: FPH, FPHH, and likely DUH2. Therefore, KITLG is an important modulator of skin pigmentation.Journal of Investigative Dermatology advance...

Clinical study of DMD gene point mutation causing Becker muscular dystrophy

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Ji-qing CAO

2015-07-01

Full Text Available Background  DMD gene point mutation, mainly nonsense mutation, always cause the most severe Duchenne muscular dystrophy (DMD. However, we also observed some cases of Becker muscular dystrophy (BMD carrying DMD point mutation. This paper aims to explore the mechanism of DMD point mutation causing BMD, in order to enhance the understanding of mutation types of BMD.  Methods  Sequence analysis was performed in 11 cases of BMD confirmed by typical clinical manifestations and muscle biopsy. The exon of DMD gene was detected non-deletion or duplication by multiplex ligation-dependent probe amplification (MLPA.  Results  Eleven patients carried 10 mutation types without mutational hotspot. Six patients carried nonsense mutations [c.5002G>T, p.(Glu1668X; c.1615C > T, p.(Arg539X; c.7105G > T, p.(Glu2369X; c.5287C > T, p.(Arg1763X; c.9284T > G, p.(Leu3095X]. One patient carried missense mutation [c.5234G > A, p.(Arg1745His]. Two patients carried frameshift mutations (c.10231dupT, c.10491delC. Two patients carried splicing site mutations (c.4518 + 3A > T, c.649 + 2T > C.  Conclusions  DMD gene point mutation may result in BMD with mild clinical symptoms. When clinical manifestations suggest the possibility of BMD and MLPA reveals non?deletion or duplication mutation of DMD gene, BMD should be considered. Study on the mechanism of DMD point mutation causing BMD is very important for gene therapy of DMD. DOI: 10.3969/j.issn.1672-6731.2015.06.005

Radiation-induced mutations in mammals

International Nuclear Information System (INIS)

Ehling, U.H.

1993-01-01

The aims of the proposed project are to provide a better basis for extrapolation of animal data to man. Genetic endpoint, strain and species comparisons are made, which will provide critical experimental data regarding strategies in extrapolating laboratory animal data to man. Experiments were conducted to systematically compare the spontaneous and radiation-induced mutation rates for recessive specific-locus, dominant cataract and enzyme activity alleles in the mouse as well as a comparison of the mutation rate in the mouse and hamster for dominant cataract and enzyme activity alleles. The comparison of the radiation-dose response for recessive specific-locus and dominant cataract mutations are extended. Selected mutations are characterized at the genetic, biochemical and molecular levels. (R.P.) 5 refs., 3 tabs

Characterization of carbon ion-induced mutations in Arabidopsis thaliana

International Nuclear Information System (INIS)

Shikazono, N.; Suzuki, C.; Kitamura, S.; Watanabe, H.; Tano, S.; Tanaka, A.

2003-01-01

Full text: Irradiation of Arabidopsis thaliana by carbon ions was carried out to investigate the mutational effect of ion particles in higher plants. The averaged mutation rate of carbon ions was 2.0 X 10 -6 / Gy, which was 18-fold higher than that of electrons. PCR analysis of the carbon ion-induced mutants showed that, out of 28 mutant alleles, 14 had point-like mutations within the gene, while 14 contained large structural alterations. In the case of 12 electron-induced mutants, 9 had point-like mutations within the gene, while 3 contained large structural alterations. These results suggest that carbon ions are more likely to induce large structural alterations compared with electrons. Further sequence analysis revealed that most of the point-like mutations induced by carbon ions were short deletions. In the case of rearrangements, DNA strand breaks were found to be rejoined using, if present, short homologous sequences for both types of radiation. After carbon ion-irradiation, small deletions were frequently observed around the breakpoints, whereas duplications of terminal sequence were found after electron-irradiation. These results suggest that non-homologous end joining (NHEJ) pathway operates after plant cells are exposed to both ion particles and electrons but that different mode of rejoining deals with the broken ends produced by each radiation. From the present results, it seems reasonable to assume that carbon ions could predominantly induce null mutations in Arabidopsis. The fact that the molecular nature of carbon ion-induced mutation was different from that of electrons and that the molecular mechanisms of cells to induce mutations appeared to be also different implicates that ion particle is not only valuable as a new mutagen but also useful as a new tool to study repair mechanisms of certain types of DNA damage

Radiation-induced mutation at minisatellite loci

International Nuclear Information System (INIS)

Dubrova, Y.E.; Nesterov, V.N.; Krouchinsky, N.G.

1997-01-01

We are studying the radiation-induced increase of mutation rate in minisatellite loci in mice and humans. Minisatellite mutations were scored by multilocus DNA fingerprint analysis in the progeny of γ-irradiated and non-irradiated mice. The frequency of mutation in offspring of irradiated males was 1.7 higher that in the control group. Germline mutation at human minisatellite loci was studied among children born in heavily polluted areas of the Mogilev district of Belarus after the Chernobyl accident and in a control population. The frequency of mutation assayed both by DNA fingerprinting and by eight single locus probes was found to be two times higher in the exposed families than in the control group. Furthermore, mutation rate was correlated with the parental radiation dose for chronic exposure 137 Cs, consistent with radiation-induction of germline mutation. The potential use of minisatellites in monitoring germline mutation in humans will be discussed

ENU mutagenesis reveals a novel phenotype of reduced limb strength in mice lacking fibrillin 2.

Directory of Open Access Journals (Sweden)

Gaynor Miller

2010-02-01

Full Text Available Fibrillins 1 (FBN1 and 2 (FBN2 are components of microfibrils, microfilaments that are present in many connective tissues, either alone or in association with elastin. Marfan's syndrome and congenital contractural arachnodactyly (CCA result from dominant mutations in the genes FBN1 and FBN2 respectively. Patients with both conditions often present with specific muscle atrophy or weakness, yet this has not been reported in the mouse models. In the case of Fbn1, this is due to perinatal lethality of the homozygous null mice making measurements of strength difficult. In the case of Fbn2, four different mutant alleles have been described in the mouse and in all cases syndactyly was reported as the defining phenotypic feature of homozygotes.As part of a large-scale N-ethyl-N-nitrosourea (ENU mutagenesis screen, we identified a mouse mutant, Mariusz, which exhibited muscle weakness along with hindlimb syndactyly. We identified an amber nonsense mutation in Fbn2 in this mouse mutant. Examination of a previously characterised Fbn2-null mutant, Fbn2(fp, identified a similar muscle weakness phenotype. The two Fbn2 mutant alleles complement each other confirming that the weakness is the result of a lack of Fbn2 activity. Skeletal muscle from mutants proved to be abnormal with higher than average numbers of fibres with centrally placed nuclei, an indicator that there are some regenerating muscle fibres. Physiological tests indicated that the mutant muscle produces significantly less maximal force, possibly as a result of the muscles being relatively smaller in Mariusz mice.These findings indicate that Fbn2 is involved in integrity of structures required for strength in limb movement. As human patients with mutations in the fibrillin genes FBN1 and FBN2 often present with muscle weakness and atrophy as a symptom, Fbn2-null mice will be a useful model for examining this aspect of the disease process further.

Induced mutations in chickpea (Cicer arietinum L.) II. frequency and spectrum of chlorophyll mutations

International Nuclear Information System (INIS)

Kharkwal, M.C.

1998-01-01

A comparative study of frequency and spectrum of chlorophyll mutations induced by two physical (gamma rays, fast neutrons) and two chemical mutagens (NMU, EMS) in relation to the effects in M1 plants and induction of mutations in M2 was made in four chickpea (Cicer arietinum L.) varieties, two desi (G 130 & H 214) one Kabuli (C 104) and one green seeded (L 345). The treatments included three doses each of gamma rays (400, 500 & 600 Gy) and fast neutrons (5, 10 & 15 Gy) and two concentrations with two different durations of two chemical mutagens, NMU [0.01% (20h), & 0.02% (8h)] and EMS [0.1% (20h) & 0.2% (8h)]. The frequencies and spectrum of three different kinds of induced chlorophyll mutations in the order albina (43.5%), chlorina (27.3%) and xantha (24.2%) were recorded. Chemical mutagens were found to be efficient in inducing chlorophyll mutations in chickpea. Highest frequency of mutations was observed in green seeded var. L 345 (83% of M1 families and 19.9/1000 M2 plants). Kabuli var. C 104 was least responsive for chlorophyll mutations

Real-time resolution of point mutations that cause phenovariance in mice

Science.gov (United States)

Wang, Tao; Zhan, Xiaowei; Bu, Chun-Hui; Lyon, Stephen; Pratt, David; Hildebrand, Sara; Choi, Jin Huk; Zhang, Zhao; Zeng, Ming; Wang, Kuan-wen; Turer, Emre; Chen, Zhe; Zhang, Duanwu; Yue, Tao; Wang, Ying; Shi, Hexin; Wang, Jianhui; Sun, Lei; SoRelle, Jeff; McAlpine, William; Hutchins, Noelle; Zhan, Xiaoming; Fina, Maggy; Gobert, Rochelle; Quan, Jiexia; Kreutzer, McKensie; Arnett, Stephanie; Hawkins, Kimberly; Leach, Ashley; Tate, Christopher; Daniel, Chad; Reyna, Carlos; Prince, Lauren; Davis, Sheila; Purrington, Joel; Bearden, Rick; Weatherly, Jennifer; White, Danielle; Russell, Jamie; Sun, Qihua; Tang, Miao; Li, Xiaohong; Scott, Lindsay; Moresco, Eva Marie Y.; McInerney, Gerald M.; Karlsson Hedestam, Gunilla B.; Xie, Yang; Beutler, Bruce

2015-01-01

With the wide availability of massively parallel sequencing technologies, genetic mapping has become the rate limiting step in mammalian forward genetics. Here we introduce a method for real-time identification of N-ethyl-N-nitrosourea-induced mutations that cause phenotypes in mice. All mutations are identified by whole exome G1 progenitor sequencing and their zygosity is established in G2/G3 mice before phenotypic assessment. Quantitative and qualitative traits, including lethal effects, in single or multiple combined pedigrees are then analyzed with Linkage Analyzer, a software program that detects significant linkage between individual mutations and aberrant phenotypic scores and presents processed data as Manhattan plots. As multiple alleles of genes are acquired through mutagenesis, pooled “superpedigrees” are created to analyze the effects. Our method is distinguished from conventional forward genetic methods because it permits (1) unbiased declaration of mappable phenotypes, including those that are incompletely penetrant (2), automated identification of causative mutations concurrent with phenotypic screening, without the need to outcross mutant mice to another strain and backcross them, and (3) exclusion of genes not involved in phenotypes of interest. We validated our approach and Linkage Analyzer for the identification of 47 mutations in 45 previously known genes causative for adaptive immune phenotypes; our analysis also implicated 474 genes not previously associated with immune function. The method described here permits forward genetic analysis in mice, limited only by the rates of mutant production and screening. PMID:25605905

Age-related increase in the rate of spontaneou and γ-ray-induced hprt mutations in mouse spleen lymphocytes

International Nuclear Information System (INIS)

Gazlev, A.I.; Podlutskii, A.Ya.; Bradbury, R.

1994-01-01

Endogenous and exogenous factors continually afflict DNA of cells of organisms. A certain amount of the damage is accumulated causing mutations, increasing the risk of malignacies, impairing cell functions, and upsetting the body's homeostasis. The research reported here studies the rates of spontaneous hprt nmutationsand those induced you ggammairradiation in the splenocytes of mice at various ages. The rate of spontaneous and induced hprt gene mutations increases with aging. In gamma irradiated mice the rate of radiation-induced mutations depended on the absorbed dose and age, with the rate 2.3-3.0 fold higher in 104-110 week old mice than in younger pups. 15 refs., 1 tab

Radiation induced mutations for plant selection

International Nuclear Information System (INIS)

Brunner, H.

1994-01-01

The successful use of plant breeding for improving crops requires the existence of genetic variation of useful traits. Unfortunately, the desired variation is often lacking. However, radiation can be used to induce mutations and thereby generate genetic variation from which desired mutants may be selected. Mutation induction has become a proven way of creating variation within a crop variety. It offers the possibility of inducing desired attributes that either cannot be expressed in nature or have been lost during evolution. More than 1700 mutant cultivars of crop plants with significantly improved attributes such as increased yield, improved quality, disease and stress resistance, have been released worldwide in the last thirty years. The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has contributed to these achievements through the promotion of research and development in mutation breeding techniques using nuclear and related biotechnological methods and the provision of in plant breeding is then transferred to Member States of the IAEA and the FAO through training in mutation breeding methods and the provision of technical advice. Moreover, radiation treatment services are provided to foster applications of nuclear techniques in crop improvement programmes of member states and more specifically to render direct support to plant breeders by efficient generation of mutations. Plant materials are standardized prior to radiation exposure to warrant reproducibility of the induced effects within practical limits and a radiosensitivity test is implemented to affirm useful doses for applied objectives of a request. This review deals with irradiation methods applied at the IAEA laboratories for the efficient induction of mutations in seeds, vegetative propagules and tissue and cell cultures and the establishment of genetically variable populations upon which selection of desired traits can be based. 3 tabs., 18 refs. (author)

Biallelic mutations in BRCA1 cause a new Fanconi anemia subtype.

Science.gov (United States)

Sawyer, Sarah L; Tian, Lei; Kähkönen, Marketta; Schwartzentruber, Jeremy; Kircher, Martin; Majewski, Jacek; Dyment, David A; Innes, A Micheil; Boycott, Kym M; Moreau, Lisa A; Moilanen, Jukka S; Greenberg, Roger A

2015-02-01

Deficiency in BRCA-dependent DNA interstrand crosslink (ICL) repair is intimately connected to breast cancer susceptibility and to the rare developmental syndrome Fanconi anemia. Bona fide Fanconi anemia proteins, BRCA2 (FANCD1), PALB2 (FANCN), and BRIP1 (FANCJ), interact with BRCA1 during ICL repair. However, the lack of detailed phenotypic and cellular characterization of a patient with biallelic BRCA1 mutations has precluded assignment of BRCA1 as a definitive Fanconi anemia susceptibility gene. Here, we report the presence of biallelic BRCA1 mutations in a woman with multiple congenital anomalies consistent with a Fanconi anemia-like disorder and breast cancer at age 23. Patient cells exhibited deficiency in BRCA1 and RAD51 localization to DNA-damage sites, combined with radial chromosome formation and hypersensitivity to ICL-inducing agents. Restoration of these functions was achieved by ectopic introduction of a BRCA1 transgene. These observations provide evidence in support of BRCA1 as a new Fanconi anemia gene (FANCS). We establish that biallelic BRCA1 mutations cause a distinct FA-S, which has implications for risk counselling in families where both parents harbor BRCA1 mutations. The genetic basis of hereditary cancer susceptibility syndromes provides diagnostic information, insights into treatment strategies, and more accurate recurrence risk counseling to families. ©2014 American Association for Cancer Research.

A nonsense mutation in FMR1 causing fragile X syndrome

DEFF Research Database (Denmark)

Grønskov, Karen; Brøndum-Nielsen, Karen; Dedic, Alma

2011-01-01

Fragile X syndrome is a common cause of inherited intellectual disability. It is caused by lack of the FMR1 gene product FMRP. The most frequent cause is the expansion of a CGG repeat located in the 5'UTR of FMR1. Alleles with 200 or more repeats become hypermethylated and transcriptionally silent....... Only few patients with intragenic point mutations in FMR1 have been reported and, currently, routine analysis of patients referred for fragile X syndrome includes solely analysis for repeat expansion and methylation status. We identified a substitution in exon 2 of FMR1, c.80C>A, causing a nonsense...... mutation p.Ser27X, in a patient with classical clinical symptoms of fragile X syndrome. The mother who carried the mutation in heterozygous form presented with mild intellectual impairment. We conclude that further studies including western blot and DNA sequence analysis of the FMR1 gene should...

Mutations in XRCC4 cause primordial dwarfism without causing immunodeficiency.

Science.gov (United States)

Saito, Shinta; Kurosawa, Aya; Adachi, Noritaka

2016-08-01

In successive reports from 2014 to 2015, X-ray repair cross-complementing protein 4 (XRCC4) has been identified as a novel causative gene of primordial dwarfism. XRCC4 is indispensable for non-homologous end joining (NHEJ), the major pathway for repairing DNA double-strand breaks. As NHEJ is essential for V(D)J recombination during lymphocyte development, it is generally believed that abnormalities in XRCC4 cause severe combined immunodeficiency. Contrary to expectations, however, no overt immunodeficiency has been observed in patients with primordial dwarfism harboring XRCC4 mutations. Here, we describe the various XRCC4 mutations that lead to disease and discuss their impact on NHEJ and V(D)J recombination.

R and D activities on radiation induced mutation breeding

International Nuclear Information System (INIS)

Lapade, A.G.; Asencion, A.B.; Santos, I.S.; Grafia, A.O.; Veluz, AM.S.; Barrida, A.C.; Marbella, L.J.

1996-01-01

This paper summarizes the accomplishments, prospects and future plans of mutation breeding for crop improvement at the Philippine Nuclear Research Institute (PNRI). Mutation induction has become a proven way creating variation within a crop variety and inducing desired attributes that cannot be found in nature or have been lost during evolution. Several improved varieties with desirable traits were successfully developed through induced mutation breeding at our research institute. In rice, mutation breeding has resulted in the development of new varieties: (1) PARC 2, (2) Milagrosa mutant, (3) Bengawan mutant and (4) Azmil mutant. Mutation breeding in leguminous crops has led to the induction of an improved L 114 soybean mutant that is shorter that the original variety but yield about 40% more. Several PAEC mungbean varieties characterized with long pods that are non-shattering were also induced. In asexually propagated crops, an increase in yield and chlorophyll mutants were obtained in sweet potatos. Likewise, chlorophyll mutant which look-like 'ornamental bromeliads' and a mutant with reduced spines have been developed in pineapple Queen variety. At present, we have started a new project in mutation breeding in ornamentals. Tissue culture is being utilized in our mutation breeding program. In the near future, radiation induced mutagenesis coupled with in vitro culture techniques on protoplast culture and somatic hybridization will be integrated into our mutation breeding program to facilitate the production of new crop varieties. (author)

Induced mutations for human welfare through agriculture

International Nuclear Information System (INIS)

Patil, S.A.

2009-01-01

Full text: Use of induced mutation for crop improvement started in 1920's. It gained momentum in 1960's when IAEA and FAO started training and guidance and funds were made available for undertaking mutation breeding. IARI established a Gamma Garden and a separate institution was carved by name 'Nuclear Research Laboratory' in 1970's. ICAR Institutes and State Agriculture Universities started using this facility for crop improvement. Similarly, BARC started extending its help for irradiating the seed material specially X-rays and it became one of the major source of generating variability for crop improvement. Induced mutation has resulted in development of more than 3000 varieties of different food, feed, fruit, vegetables and flowers. Apart from direct use of mutants as cultivars, mutants have played a vital role in creating useful variation for application in basic research and gene discovery. It has helped in increasing yield through use of heterosis by inducing male sterility. It has been used for creating useful variation for changing grain composition to improve nutrition and grain quality parameters, for tolerance against abiotic and biotic stresses. Gene sequencing and related technologies have opened up new application of induced mutations. In model organisms induced mutations provide new opportunities for identification of genes/bio-chemical, cellular, developmental or functional pathways. The use of stable isotopes in basic research is of fundamental use in crop improvement. Apart from crop improvement the nuclear technology has been used for numerous other applications in Agriculture such as soil fertility, plant nutrition, use of fertilizer and irrigation, control of insect pest and storage. In recent decades BARC has come in a big way through funding for projects to State Agricultural Universities and ICAR Institutes and has signed MoU's with few of the Agriculture Universities for testing and popularizing their identified field crop varieties in

Analysis of trafficking, stability and function of human connexin 26 gap junction channels with deafness-causing mutations in the fourth transmembrane helix.

Directory of Open Access Journals (Sweden)

Cinzia Ambrosi

Full Text Available Human Connexin26 gene mutations cause hearing loss. These hereditary mutations are the leading cause of childhood deafness worldwide. Mutations in gap junction proteins (connexins can impair intercellular communication by eliminating protein synthesis, mis-trafficking, or inducing channels that fail to dock or have aberrant function. We previously identified a new class of mutants that form non-functional gap junction channels and hemichannels (connexons by disrupting packing and inter-helix interactions. Here we analyzed fourteen point mutations in the fourth transmembrane helix of connexin26 (Cx26 that cause non-syndromic hearing loss. Eight mutations caused mis-trafficking (K188R, F191L, V198M, S199F, G200R, I203K, L205P, T208P. Of the remaining six that formed gap junctions in mammalian cells, M195T and A197S formed stable hemichannels after isolation with a baculovirus/Sf9 protein purification system, while C202F, I203T, L205V and N206S formed hemichannels with varying degrees of instability. The function of all six gap junction-forming mutants was further assessed through measurement of dye coupling in mammalian cells and junctional conductance in paired Xenopus oocytes. Dye coupling between cell pairs was reduced by varying degrees for all six mutants. In homotypic oocyte pairings, only A197S induced measurable conductance. In heterotypic pairings with wild-type Cx26, five of the six mutants formed functional gap junction channels, albeit with reduced efficiency. None of the mutants displayed significant alterations in sensitivity to transjunctional voltage or induced conductive hemichannels in single oocytes. Intra-hemichannel interactions between mutant and wild-type proteins were assessed in rescue experiments using baculovirus expression in Sf9 insect cells. Of the four unstable mutations (C202F, I203T, L205V, N206S only C202F and N206S formed stable hemichannels when co-expressed with wild-type Cx26. Stable M195T hemichannels

Disabilities caused by unstable mutations in Costa Rica

OpenAIRE

Morales Montero, Fernando; Cuenca Berger, Patricia; Castro Volio, Isabel

2004-01-01

Myotonic dystrophy and fragile X syndrome are two genetically determined relatively common disabilities. Both are examples of a new type of mutation mechanism called unstable or dynamic mutations, triple repeats expansions or DNA amplification. Fragile X syndrome is recognized as the main cause of hereditary mental retardation and myotonic dystrophy is considered the most common muscular dystrophy of adults. This is a prospective non randomized study of clinically affected people,...

Most ultraviolet irradiation induced mutations in the nematode Caenorhabditis elegans are chromosomal rearrangements

International Nuclear Information System (INIS)

Stewart, H.I.; Rosenbluth, R.E.; Baillie, D.L.

1991-01-01

In this study the utility of 254-nm ultraviolet light (UV) as a magnetic tool in C.elegans is determined. It is demonstrated that irradiation of adult hermaphrodites provides a simple method for the induction of heritable chromosomal rearrangements. A screening protocol was employed that identifies either recessive lethal mutations in the 40 map unit region balanced by the translocation eT1(III;V), or unc-36(III) duplications. Mutations were recovered in 3% of the chromosomes screened after a dose of 120 J/m 2 . This rate resembles that for 1500 R γ-ray-induced mutations selected in a similar manner. The mutations were classified either as lethals [mapping to Linkage Group (LG)III or LGV] or as putative unc-36 duplications. In contrast to the majority of UV-induced mutations analysed in micro-organisms, a large fraction of the C.elegans UV-induced mutations were found to be not simple intragenic lesions, but deficiencies for more than one adjacent gene or more complex events. Preliminary evidence for this conclusion came from the high frequency of mutations that had a dominant effect causing reduced numbers of adult progeny. Subsequently 6 out of 9 analysed LGV mutations were found to be deficiencies. Other specific rearrangements also identified were: one translocation, sT5(II;III), and two unc-36 duplications, sDp8 and sDp9. It was concluded that UV irradiation can easily be used as an additional tool for the analysis of C.elegans chromosomes, and that C.elegans should prove to be a useful organism in which to study the mechanisms whereby UV acts as a mutagen in cells of complex eukaryotes. (author). 46 refs.; 5 figs.; 4 tabs

Kinetics of gene and chromosome mutations induced by UV-C in yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Koltovaya, N.; Kokoreva, A.; Senchenko, D.; Shvaneva, N.; Zhuchkina, N.

2017-01-01

The systematic study of the kinetics of UV-induced gene and structural mutations in eukaryotic cells was carried out on the basis of model yeast S. cerevisiae. A variety of genetic assays (all types of base pair substitutions, frameshifts, forward mutations canl, chromosomal and plasmid rearrangements) in haploid strains were used. Yeast cells were treated by UV-C light of fluence of energy up to 200 J/m"2. The kinetics of the induced gene and structural mutations is represented by a linear-quadratic and exponential functions. The slope of curves in log-log plots was not constant, had the value 2-4 and depended on the interval of doses. It was suggested that it is the superposition and dynamics of different pathways form the mutagenic responses of eukaryotic cells to UV-C light that cause the high-order curves. [ru

Induced mutations - a tool in plant research

International Nuclear Information System (INIS)

1981-01-01

These proceedings include 34 papers and 18 brief descriptions of poster presentations in the following areas as they are affected by induced mutations: advancement of genetics, plant evolution, plant physiology, plant parasites, plant symbioses, in vitro culture, gene ecology and plant breeding. Only a relatively small number of papers are of direct nuclear interest essentially in view of the mutations being induced by ionizing radiations. The papers of nuclear interest have been entered as separate and individual items of input

Familial knockin mutation of LRRK2 causes lysosomal dysfunction and accumulation of endogenous insoluble α-synuclein in neurons.

Science.gov (United States)

Schapansky, Jason; Khasnavis, Saurabh; DeAndrade, Mark P; Nardozzi, Jonathan D; Falkson, Samuel R; Boyd, Justin D; Sanderson, John B; Bartels, Tim; Melrose, Heather L; LaVoie, Matthew J

2018-03-01

Missense mutations in the multi-domain kinase LRRK2 cause late onset familial Parkinson's disease. They most commonly with classic proteinopathy in the form of Lewy bodies and Lewy neurites comprised of insoluble α-synuclein, but in rare cases can also manifest tauopathy. The normal function of LRRK2 has remained elusive, as have the cellular consequences of its mutation. Data from LRRK2 null model organisms and LRRK2-inhibitor treated animals support a physiological role for LRRK2 in regulating lysosome function. Since idiopathic and LRRK2-linked PD are associated with the intraneuronal accumulation of protein aggregates, a series of critical questions emerge. First, how do pathogenic mutations that increase LRRK2 kinase activity affect lysosome biology in neurons? Second, are mutation-induced changes in lysosome function sufficient to alter the metabolism of α-synuclein? Lastly, are changes caused by pathogenic mutation sensitive to reversal with LRRK2 kinase inhibitors? Here, we report that mutation of LRRK2 induces modest but significant changes in lysosomal morphology and acidification, and decreased basal autophagic flux when compared to WT neurons. These changes were associated with an accumulation of detergent-insoluble α-synuclein and increased neuronal release of α-synuclein and were reversed by pharmacologic inhibition of LRRK2 kinase activity. These data demonstrate a critical and disease-relevant influence of native neuronal LRRK2 kinase activity on lysosome function and α-synuclein homeostasis. Furthermore, they also suggest that lysosome dysfunction, altered neuronal α-synuclein metabolism, and the insidious accumulation of aggregated protein over decades may contribute to pathogenesis in this late-onset form of familial PD. Copyright © 2017 Elsevier Inc. All rights reserved.

Hot-spot KIF5A mutations cause familial ALS

Science.gov (United States)

Yilmaz, Rüstem; Müller, Kathrin; Grehl, Torsten; Petri, Susanne; Meyer, Thomas; Grosskreutz, Julian; Weydt, Patrick; Ruf, Wolfgang; Neuwirth, Christoph; Weber, Markus; Pinto, Susana; Claeys, Kristl G; Schrank, Berthold; Jordan, Berit; Knehr, Antje; Günther, Kornelia; Hübers, Annemarie; Zeller, Daniel; Kubisch, Christian; Jablonka, Sibylle; Klopstock, Thomas; de Carvalho, Mamede; Sperfeld, Anne; Borck, Guntram; Volk, Alexander E; Dorst, Johannes; Weis, Joachim; Otto, Markus; Schuster, Joachim; Del Tredici, Kelly; Braak, Heiko; Danzer, Karin M; Freischmidt, Axel; Meitinger, Thomas; Strom, Tim M; Ludolph, Albert C; Andersen, Peter M; Weishaupt, Jochen H; Weyen, Ute; Hermann, Andreas; Hagenacker, Tim; Koch, Jan Christoph; Lingor, Paul; Göricke, Bettina; Zierz, Stephan; Baum, Petra; Wolf, Joachim; Winkler, Andrea; Young, Peter; Bogdahn, Ulrich; Prudlo, Johannes; Kassubek., Jan

2018-01-01

Abstract Heterozygous missense mutations in the N-terminal motor or coiled-coil domains of the kinesin family member 5A (KIF5A) gene cause monogenic spastic paraplegia (HSP10) and Charcot-Marie-Tooth disease type 2 (CMT2). Moreover, heterozygous de novo frame-shift mutations in the C-terminal domain of KIF5A are associated with neonatal intractable myoclonus, a neurodevelopmental syndrome. These findings, together with the observation that many of the disease genes associated with amyotrophic lateral sclerosis disrupt cytoskeletal function and intracellular transport, led us to hypothesize that mutations in KIF5A are also a cause of amyotrophic lateral sclerosis. Using whole exome sequencing followed by rare variant analysis of 426 patients with familial amyotrophic lateral sclerosis and 6137 control subjects, we detected an enrichment of KIF5A splice-site mutations in amyotrophic lateral sclerosis (2/426 compared to 0/6137 in controls; P = 4.2 × 10−3), both located in a hot-spot in the C-terminus of the protein and predicted to affect splicing exon 27. We additionally show co-segregation with amyotrophic lateral sclerosis of two canonical splice-site mutations in two families. Investigation of lymphoblast cell lines from patients with KIF5A splice-site mutations revealed the loss of mutant RNA expression and suggested haploinsufficiency as the most probable underlying molecular mechanism. Furthermore, mRNA sequencing of a rare non-synonymous missense mutation (predicting p.Arg1007Gly) located in the C-terminus of the protein shortly upstream of the splice donor of exon 27 revealed defective KIF5A pre-mRNA splicing in respective patient-derived cell lines owing to abrogation of the donor site. Finally, the non-synonymous single nucleotide variant rs113247976 (minor allele frequency = 1.00% in controls, n = 6137), also located in the C-terminal region [p.(Pro986Leu) in exon 26], was significantly enriched in familial amyotrophic lateral sclerosis patients (minor

Induced mutations for crop improvement- the generation next

International Nuclear Information System (INIS)

Bhatia, C.R.

2000-01-01

Experiments to use induced mutations for the improvement of crop plants were initiated in the country in mid nineteen fifties. After forty five years and reasonably good success stories, it is no longer an attractive subject for bright young graduate students. The areas of intellectually satisfying, contemporary, plant genetics based on induced mutations that can also bring social and commercial benefits are identified. These are: nodulation mutants in legumes, altering fatty acid composition in oil crops, modification of root characters, altering host-pathogen interactions, flowering time, day length insensitivity and some changes in modulation pattern involve mutations

DNA sequence analysis of X-ray induced Adh null mutations in Drosophila melanogaster

International Nuclear Information System (INIS)

Mahmoud, J.; Fossett, N.G.; Arbour-Reily, P.; McDaniel, M.; Tucker, A.; Chang, S.H.; Lee, W.R.

1991-01-01

The mutational spectrum for 28 X-ray induced mutations and 2 spontaneous mutations, previously determined by genetic and cytogenetic methods, consisted of 20 multilocus deficiencies (19 induced and 1 spontaneous) and 10 intragenic mutations (9 induced and 1 spontaneous). One of the X-ray induced intragenic mutations was lost, and another was determined to be a recombinant with the allele used in the recovery scheme. The DNA sequence of two X-ray induced intragenic mutations has been published. This paper reports the results of DNA sequence analysis of the remaining intragenic mutations and a summary of the X-ray induced mutational spectrum. The combination of DNA sequence analysis with genetic complementation analysis shows a continuous distribution in size of deletions rather than two different types of mutations consisting of deletions and 'point mutations'. Sequencing is shown to be essential for detecting intragenic deletions. Of particular importance for future studies is the observation that all of the intragenic deletions consist of a direct repeat adjacent to the breakpoint with one of the repeats deleted

Novel GABRG2 mutations cause familial febrile seizures

Science.gov (United States)

Boillot, Morgane; Morin-Brureau, Mélanie; Picard, Fabienne; Weckhuysen, Sarah; Lambrecq, Virginie; Minetti, Carlo; Striano, Pasquale; Zara, Federico; Iacomino, Michele; Ishida, Saeko; An-Gourfinkel, Isabelle; Daniau, Mailys; Hardies, Katia; Baulac, Michel; Dulac, Olivier; Leguern, Eric; Nabbout, Rima

2015-01-01

Objective: To identify the genetic cause in a large family with febrile seizures (FS) and temporal lobe epilepsy (TLE) and subsequently search for additional mutations in a cohort of 107 families with FS, with or without epilepsy. Methods: The cohort consisted of 1 large family with FS and TLE, 64 smaller French families recruited through a national French campaign, and 43 Italian families. Molecular analyses consisted of whole-exome sequencing and mutational screening. Results: Exome sequencing revealed a p.Glu402fs*3 mutation in the γ2 subunit of the GABAA receptor gene (GABRG2) in the large family with FS and TLE. Three additional nonsense and frameshift GABRG2 mutations (p.Arg136*, p.Val462fs*33, and p.Pro59fs*12), 1 missense mutation (p.Met199Val), and 1 exonic deletion were subsequently identified in 5 families of the follow-up cohort. Conclusions: We report GABRG2 mutations in 5.6% (6/108) of families with FS, with or without associated epilepsy. This study provides evidence that GABRG2 mutations are linked to the FS phenotype, rather than epilepsy, and that loss-of-function of GABAA receptor γ2 subunit is the probable underlying pathogenic mechanism. PMID:27066572

Somatic mutations in leafs of tobacco seedlings induced by ionizing radiation and pesticide

International Nuclear Information System (INIS)

Shin, H. S.; Kim, J. K.; Song, H. S.; Lee, Y. I.

2001-01-01

Somatic mutations induced by the combined treatment of pesticide and ionizing radiation were analyzed in the leaves of tobacco seedlings. The pesticide (1,5 and 10 ppm of parathion) was sprayed directly onto the seedlings. The seedlings, with or without pretreatment of pesticide, were irradiated with 0.1 ∼10 Gy of gamma ray. The difference in the somatic mutation frequencies were not significant among groups treated with different concentration of pesticide. The somatic mutations in tobacco seedlings irradiated with gamma-ray showed a clear dose-response relationship in a range of 0.1 to 10 Gy. However, the combined treatment of pesticide and radiation did not cause any synergistic enhancement in the mutation frequencies. The highest efficiency in the induction of somatic mutations could be obtained by irradiating the seedlings with 5 Gy, 12 hours after 1 ppm of pesticide treatment, or 24 hours after 5 ppm of pesticide treatment

Dominant de novo DSP mutations cause erythrokeratodermia-cardiomyopathy syndrome.

Science.gov (United States)

Boyden, Lynn M; Kam, Chen Y; Hernández-Martín, Angela; Zhou, Jing; Craiglow, Brittany G; Sidbury, Robert; Mathes, Erin F; Maguiness, Sheilagh M; Crumrine, Debra A; Williams, Mary L; Hu, Ronghua; Lifton, Richard P; Elias, Peter M; Green, Kathleen J; Choate, Keith A

2016-01-15

Disorders of keratinization (DOK) show marked genotypic and phenotypic heterogeneity. In most cases, disease is primarily cutaneous, and further clinical evaluation is therefore rarely pursued. We have identified subjects with a novel DOK featuring erythrokeratodermia and initially-asymptomatic, progressive, potentially fatal cardiomyopathy, a finding not previously associated with erythrokeratodermia. We show that de novo missense mutations clustered tightly within a single spectrin repeat of DSP cause this novel cardio-cutaneous disorder, which we term erythrokeratodermia-cardiomyopathy (EKC) syndrome. We demonstrate that DSP mutations in our EKC syndrome subjects affect localization of desmosomal proteins and connexin 43 in the skin, and result in desmosome aggregation, widening of intercellular spaces, and lipid secretory defects. DSP encodes desmoplakin, a primary component of desmosomes, intercellular adhesion junctions most abundant in the epidermis and heart. Though mutations in DSP are known to cause other disorders, our cohort features the unique clinical finding of severe whole-body erythrokeratodermia, with distinct effects on localization of desmosomal proteins and connexin 43. These findings add a severe, previously undescribed syndrome featuring erythrokeratodermia and cardiomyopathy to the spectrum of disease caused by mutation in DSP, and identify a specific region of the protein critical to the pathobiology of EKC syndrome and to DSP function in the heart and skin. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Induced Mutations in Thai Rice

International Nuclear Information System (INIS)

Klakhaeng, Kanchana

2014-01-01

Rice is the primary source of food for more than half of the world's population. It benefits greatly from technological inputs in the area of breeding such as induced mutation. Induced mutation can produce mutants with significant improvement in plant type, maturity, yields and protein ratio when compared to the parent. These improved traits enable the mutants to fit into farming systems with either shorter or longer growing seasons. Three induced mutant rice varieties, including RD6, RD10 and RD15, are well accepted by farmers and consumers in Thailand. RD6 and RD15 were aromatic, photosensitive varieties which were derived from KDML105 by acute irradiation of 20 and 15 kilorad gamma ray, respectively. After induced mutation, pedigree selection was applied. RD6 showed drought tolerance and also good grain quality including softness and good aroma with a higher average yield than the famous glutinous variety, San-Pah-Tong. Additionally, it was resistant to blast and brown spot diseases with an average yield of 4.19 tons/ha. RD15 showed drought tolerance and resistance to brown spot disease with the highest yield of 3.5 tons/ha. These two mutant varieties are currently the most famous aromatic rice varieties in Thailand. On the other hand, RD10 is a glutinous, photoperiod insensitive rice variety which was derived from RD1 by irradiation of 1 kilorad fast neutrons. RD10 showed good grain quality such as softness and stickiness with the yield of 4.25 tons/ha. As an on-going project, recommended rice varieties were irradiated with electron beam for anaerobic germination ability, submergence tolerance, stagnant-flood tolerance and also internode elongation.

Fate of induced mutations in higher plants with special emphasis on sexually reproducing species

International Nuclear Information System (INIS)

Cornu, Andre

1978-01-01

A mutation induced in a plant somatic cell has to overcome quite many difficulties before being isolated and utilized as a marker in a mutated line. If induced in a meristem, three conditions must be fulfilled for the mutation to be transmitted to the subsequent generation: it must be compatible with normal cell multiplication, it must be located in a cell mass that will provide an inflorescence, and it must be in the sporogenetic layer (t2). Under these conditions, or if it is induced in a gamete or in a zygote, the mutation enters a first cycle of sexual reproduction. Meiosis and the subsequent haploid phase constitute severe screening steps for many chromosome aberrations. Studies on Petunia performed by means of marker genes show that male and female gametic viabilities are drastically impaired by deletions. However, a deficient chromosome can be transmitted when the losss of information is compensated for by homologous information as, for example, diploid gametes from tetraploids or disomic gametes resulting from non-disjunction. If partial or complete sterility, whether sporo- or gametophytic, is avoided, then the mutation can be transmitted to the next generation in heterozygous state. When becoming homozygous, the mutation may have effects such that its use can be most difficult. This is the case when this mutation causes rather early lethality or severe sterility. Thus, in higher plants, one faces several cases of powerful and efficient selection against mutations. On the basis of experiments carried out on Petunia, the per locus mutation rate of practical interest ranges between I and 5/10000M 1 plants. Practical conclusions are drawn about which organ should be treated, which mutagen at what dose should be used according to the scope of the research undertaken [fr

Specificity of mutations induced by carbon ions in budding yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Matuo, Youichirou; Nishijima, Shigehiro; Hase, Yoshihiro; Sakamoto, Ayako; Tanaka, Atsushi; Shimizu, Kikuo

2006-01-01

To investigate the nature of mutations induced by accelerated ions in eukaryotic cells, the effects of carbon-ion irradiation were compared with those of γ-ray irradiation in the budding yeast Saccharomyces cerevisiae. The mutational effect and specificity of carbon-ion beams were studied in the URA3 gene of the yeast. Our experiments showed that the carbon ions generated more than 10 times the number of mutations induced by γ-rays, and that the types of base changes induced by carbon ions include transversions (68.7%), transitions (13.7%) and deletions/insertions (17.6%). The transversions were mainly G:C → T:A, and all the transitions were G:C → A:T. In comparison with the surrounding sequence context of mutational base sites, the C residues in the 5'-AC(A/T)-3' sequence were found to be easily changed. Large deletions and duplications were not observed, whereas ion-induced mutations in Arabidopsis thaliana were mainly short deletions and rearrangements. The remarkable feature of yeast mutations induced by carbon ions was that the mutation sites were localized near the linker regions of nucleosomes, whereas mutations induced by γ-ray irradiation were located uniformly throughout the gene

KMeyeDB: a graphical database of mutations in genes that cause eye diseases.

Science.gov (United States)

Kawamura, Takashi; Ohtsubo, Masafumi; Mitsuyama, Susumu; Ohno-Nakamura, Saho; Shimizu, Nobuyoshi; Minoshima, Shinsei

2010-06-01

KMeyeDB (http://mutview.dmb.med.keio.ac.jp/) is a database of human gene mutations that cause eye diseases. We have substantially enriched the amount of data in the database, which now contains information about the mutations of 167 human genes causing eye-related diseases including retinitis pigmentosa, cone-rod dystrophy, night blindness, Oguchi disease, Stargardt disease, macular degeneration, Leber congenital amaurosis, corneal dystrophy, cataract, glaucoma, retinoblastoma, Bardet-Biedl syndrome, and Usher syndrome. KMeyeDB is operated using the database software MutationView, which deals with various characters of mutations, gene structure, protein functional domains, and polymerase chain reaction (PCR) primers, as well as clinical data for each case. Users can access the database using an ordinary Internet browser with smooth user-interface, without user registration. The results are displayed on the graphical windows together with statistical calculations. All mutations and associated data have been collected from published articles. Careful data analysis with KMeyeDB revealed many interesting features regarding the mutations in 167 genes that cause 326 different types of eye diseases. Some genes are involved in multiple types of eye diseases, whereas several eye diseases are caused by different mutations in one gene.

De novo mutations in ATP1A3 cause alternating hemiplegia of childhood

Science.gov (United States)

Heinzen, Erin L.; Swoboda, Kathryn J.; Hitomi, Yuki; Gurrieri, Fiorella; Nicole, Sophie; de Vries, Boukje; Tiziano, F. Danilo; Fontaine, Bertrand; Walley, Nicole M.; Heavin, Sinéad; Panagiotakaki, Eleni; Fiori, Stefania; Abiusi, Emanuela; Di Pietro, Lorena; Sweney, Matthew T.; Newcomb, Tara M.; Viollet, Louis; Huff, Chad; Jorde, Lynn B.; Reyna, Sandra P.; Murphy, Kelley J.; Shianna, Kevin V.; Gumbs, Curtis E.; Little, Latasha; Silver, Kenneth; Ptác̆ek, Louis J.; Haan, Joost; Ferrari, Michel D.; Bye, Ann M.; Herkes, Geoffrey K.; Whitelaw, Charlotte M.; Webb, David; Lynch, Bryan J.; Uldall, Peter; King, Mary D.; Scheffer, Ingrid E.; Neri, Giovanni; Arzimanoglou, Alexis; van den Maagdenberg, Arn M.J.M.; Sisodiya, Sanjay M.; Mikati, Mohamad A.; Goldstein, David B.; Nicole, Sophie; Gurrieri, Fiorella; Neri, Giovanni; de Vries, Boukje; Koelewijn, Stephany; Kamphorst, Jessica; Geilenkirchen, Marije; Pelzer, Nadine; Laan, Laura; Haan, Joost; Ferrari, Michel; van den Maagdenberg, Arn; Zucca, Claudio; Bassi, Maria Teresa; Franchini, Filippo; Vavassori, Rosaria; Giannotta, Melania; Gobbi, Giuseppe; Granata, Tiziana; Nardocci, Nardo; De Grandis, Elisa; Veneselli, Edvige; Stagnaro, Michela; Gurrieri, Fiorella; Neri, Giovanni; Vigevano, Federico; Panagiotakaki, Eleni; Oechsler, Claudia; Arzimanoglou, Alexis; Nicole, Sophie; Giannotta, Melania; Gobbi, Giuseppe; Ninan, Miriam; Neville, Brian; Ebinger, Friedrich; Fons, Carmen; Campistol, Jaume; Kemlink, David; Nevsimalova, Sona; Laan, Laura; Peeters-Scholte, Cacha; van den Maagdenberg, Arn; Casaer, Paul; Casari, Giorgio; Sange, Guenter; Spiel, Georg; Boneschi, Filippo Martinelli; Zucca, Claudio; Bassi, Maria Teresa; Schyns, Tsveta; Crawley, Francis; Poncelin, Dominique; Vavassori, Rosaria

2012-01-01

Alternating hemiplegia of childhood (AHC) is a rare, severe neurodevelopmental syndrome characterized by recurrent hemiplegic episodes and distinct neurologic manifestations. AHC is usually a sporadic disorder with unknown etiology. Using exome sequencing of seven patients with AHC, and their unaffected parents, we identified de novo nonsynonymous mutations in ATP1A3 in all seven AHC patients. Subsequent sequence analysis of ATP1A3 in 98 additional patients revealed that 78% of AHC cases have a likely causal ATP1A3 mutation, including one inherited mutation in a familial case of AHC. Remarkably, six ATP1A3 mutations explain the majority of patients, including one observed in 36 patients. Unlike ATP1A3 mutations that cause rapid-onset-dystonia-parkinsonism, AHC-causing mutations revealed consistent reductions in ATPase activity without effects on protein expression. This work identifies de novo ATP1A3 mutations as the primary cause of AHC, and offers insight into disease pathophysiology by expanding the spectrum of phenotypes associated with mutations in this gene. PMID:22842232

Effects of the umuC36 mutation on ultraviolet-radiation-induced base-change and frameshift mutations in Escherichia coli

International Nuclear Information System (INIS)

Kato, T.; Nakano, E.

1981-01-01

The effects of the umuC36 mutation on the induction of base-change and frameshift mutations were studied. An active umuC gene was necessary in either the uvr + or uvr - strains of Escherichia coli K12 for UV- and X-ray-induced mutations to His + , ColE and Spc, which are presumably base-change mutations, but it was not essential for ethyl methanesulphonate or N-methyl-N'-nitro-N-nitrosoguanidine-induced His + mutations. In contrast, only 1 out of 13 trp - frameshift mutations examined was UV reversible, and the process of mutagenesis was umuC + -dependent, whereas a potent frameshift mutagen, ICR191, effectively induced Trp + mutations in most of the strains regardless of the umu + or umuC genetic background. These results suggest that base substitutions are a major mutational type derived from the umuC + -dependent pathway of error-prone repair. (orig.)

Mutations in ROGDI Cause Kohlschutter-Tonz Syndrome

NARCIS (Netherlands)

Schossig, A.; Wolf, N.I.; Fischer, C.; Fischer, M.; Stocker, G.; Pabinger, S.; Dander, A.; Steiner, B.; Tonz, O.; Kotzot, D.; Haberlandt, E.; Amberger, A.; Burwinkel, B.; Wimmer, K.; Fauth, C.; Grond-Ginsbach, C.; Koch, M.J.; Deichmann, A.; von Kalle, C.; Bartram, C.R.; Kohlschutter, A.; Trajanoski, Z.; Zschocke, J.

2012-01-01

Kohlschütter-Tönz syndrome (KTS) is an autosomal-recessive disease characterized by the combination of epilepsy, psychomotor regression, and amelogenesis imperfecta. The molecular basis has not yet been elucidated. Here, we report that KTS is caused by mutations in ROGDI. Using a combination of

Hereditary spastic paraplegia caused by the PLP1 'rumpshaker mutation'

DEFF Research Database (Denmark)

Svenstrup, Kirsten; Giraud, Geneviève; Boespflug-Tanguy, Odile

2010-01-01

with the 'rumpshaker mutation.' PATIENTS: A family with HSP caused by the 'rumpshaker mutation.' RESULTS: The patients showed nystagmus during infancy and had early onset of HSP. They had normal cognition, and cerebral MRI showed relatively unspecific white matter abnormalities on T2 sequences without clear...

Mutations in the G6PC3 gene cause Dursun syndrome.

Science.gov (United States)

Banka, Siddharth; Newman, William G; Ozgül, R Koksal; Dursun, Ali

2010-10-01

Dursun syndrome is a triad of familial primary pulmonary hypertension, leucopenia, and atrial septal defect. Here we demonstrate that mutations in G6PC3 cause Dursun syndrome. Mutations in G6PC3 are known to also cause severe congenital neutropenia type 4. Identification of the genetic basis of Dursun syndrome expands the pre-existing knowledge about the phenotypic effects of mutations in G6PC3. We propose that Dursun syndrome should now be considered as a subset of severe congenital neutropenia type 4 with pulmonary hypertension as an important clinical feature. Copyright © 2010 Wiley-Liss, Inc.

Specificity of mutations induced by carbon ions in budding yeast Saccharomyces cerevisiae

Energy Technology Data Exchange (ETDEWEB)

Matuo, Youichirou [Graduate School of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka 565-0871 (Japan); Nishijima, Shigehiro [Graduate School of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka 565-0871 (Japan); Hase, Yoshihiro [Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Watanuki-machi 1233, Takasaki, Gunma 370-1292 (Japan); Sakamoto, Ayako [Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Watanuki-machi 1233, Takasaki, Gunma 370-1292 (Japan); Tanaka, Atsushi [Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Watanuki-machi 1233, Takasaki, Gunma 370-1292 (Japan); Shimizu, Kikuo [Radioisotope Research Center, Osaka University, Yamada-oka 2-4, Suita, Osaka 565-0871 (Japan)]. E-mail: shimizu@rirc.osaka-u.ac.jp

2006-12-01

To investigate the nature of mutations induced by accelerated ions in eukaryotic cells, the effects of carbon-ion irradiation were compared with those of {gamma}-ray irradiation in the budding yeast Saccharomyces cerevisiae. The mutational effect and specificity of carbon-ion beams were studied in the URA3 gene of the yeast. Our experiments showed that the carbon ions generated more than 10 times the number of mutations induced by {gamma}-rays, and that the types of base changes induced by carbon ions include transversions (68.7%), transitions (13.7%) and deletions/insertions (17.6%). The transversions were mainly G:C {sup {yields}} T:A, and all the transitions were G:C {sup {yields}} A:T. In comparison with the surrounding sequence context of mutational base sites, the C residues in the 5'-AC(A/T)-3' sequence were found to be easily changed. Large deletions and duplications were not observed, whereas ion-induced mutations in Arabidopsis thaliana were mainly short deletions and rearrangements. The remarkable feature of yeast mutations induced by carbon ions was that the mutation sites were localized near the linker regions of nucleosomes, whereas mutations induced by {gamma}-ray irradiation were located uniformly throughout the gene.

An inducible mouse model of podocin-mutation-related nephrotic syndrome.

Directory of Open Access Journals (Sweden)

Mansoureh Tabatabaeifar

Full Text Available Mutations in the NPHS2 gene, encoding podocin, cause hereditary nephrotic syndrome. The most common podocin mutation, R138Q, is associated with early disease onset and rapid progression to end-stage renal disease. Knock-in mice carrying a R140Q mutation, the mouse analogue of human R138Q, show developmental arrest of podocytes and lethal renal failure at neonatal age. Here we created a conditional podocin knock-in model named NPHS2 R140Q/-, using a tamoxifen-inducible Cre recombinase, which permits to study the effects of the mutation in postnatal life. Within the first week of R140Q hemizygosity induction the animals developed proteinuria, which peaked after 4-5 weeks. Subsequently the animals developed progressive renal failure, with a median survival time of 12 (95% CI: 11-13 weeks. Foot process fusion was observed within one week, progressing to severe and global effacement in the course of the disease. The number of podocytes per glomerulus gradually diminished to 18% compared to healthy controls 12-16 weeks after induction. The fraction of segmentally sclerosed glomeruli was 25%, 85% and 97% at 2, 4 and 8 weeks, respectively. Severe tubulointerstitial fibrosis was present at later disease stage and was correlated quantitatively with the level of proteinuria at early disease stages. While R140Q podocin mRNA expression was elevated, protein abundance was reduced by more than 50% within one week following induction. Whereas miRNA21 expression persistently increased during the first 4 weeks, miRNA-193a expression peaked 2 weeks after induction. In conclusion, the inducible R140Q-podocin mouse model is an auspicious model of the most common genetic cause of human nephrotic syndrome, with a spontaneous disease course strongly reminiscent of the human disorder. This model constitutes a valuable tool to test the efficacy of novel pharmacological interventions aimed to improve podocyte function and viability and attenuate proteinuria

Alkylating agent (MNU)-induced mutation in space environment

Science.gov (United States)

Ohnishi, T.; Takahashi, A.; Ohnishi, K.; Takahashi, S.; Masukawa, M.; Sekikawa, K.; Amano, T.; Nakano, T.; Nagaoka, S.

2001-01-01

In recent years, some contradictory data about the effects of microgravity on radiation-induced biological responses in space experiments have been reported. We prepared a damaged template DNA produced with an alkylating agent (N-methyl-N-nitroso urea; MNU) to measure incorrect base-incorporation during DNA replication in microgravity. We examined whether mutation frequency is affected by microgravity during DNA replication for a DNA template damaged by an alkylating agent. Using an in vitro enzymatic reaction system, DNA synthesis by Taq polymerase or polymerase III was done during a US space shuttle mission (Discovery, STS-91). After the flight, DNA replication and mutation frequencies were measured. We found that there was almost no effect of microgravity on DNA replication and mutation frequency. It is suggested that microgravity might not affect at the stage of substrate incorporation in induced-mutation frequency.

Mutation induced with ion beam irradiation in rose

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, H. E-mail: yhiroya@nias.affrc.go.jp; Nagatomi, S.; Morishita, T.; Degi, K.; Tanaka, A.; Shikazono, N.; Hase, Y

2003-05-01

The effects of mutation induction by ion beam irradiation on axillary buds in rose were investigated. Axillary buds were irradiated with carbon and helium ion beams, and the solid mutants emerged after irradiation by repeated cutting back. In helium ion irradiation, mutations were observed in plants derived from 9 buds among 56 irradiated buds in 'Orange Rosamini' and in plants derived from 10 buds among 61 irradiated buds in 'Red Minimo'. In carbon ion, mutations were observed in plants derived from 12 buds among 88 irradiated buds in 'Orange Rosamini'. Mutations were induced not only in higher doses but also in lower doses, with which physiological effect by irradiation was hardly observed. Irradiation with both ion beams induced mutants in the number of petals, in flower size, in flower shape and in flower color in each cultivar.

Hot-spot KIF5A mutations cause familial ALS.

Science.gov (United States)

Brenner, David; Yilmaz, Rüstem; Müller, Kathrin; Grehl, Torsten; Petri, Susanne; Meyer, Thomas; Grosskreutz, Julian; Weydt, Patrick; Ruf, Wolfgang; Neuwirth, Christoph; Weber, Markus; Pinto, Susana; Claeys, Kristl G; Schrank, Berthold; Jordan, Berit; Knehr, Antje; Günther, Kornelia; Hübers, Annemarie; Zeller, Daniel; Kubisch, Christian; Jablonka, Sibylle; Sendtner, Michael; Klopstock, Thomas; de Carvalho, Mamede; Sperfeld, Anne; Borck, Guntram; Volk, Alexander E; Dorst, Johannes; Weis, Joachim; Otto, Markus; Schuster, Joachim; Del Tredici, Kelly; Braak, Heiko; Danzer, Karin M; Freischmidt, Axel; Meitinger, Thomas; Strom, Tim M; Ludolph, Albert C; Andersen, Peter M; Weishaupt, Jochen H

2018-01-12

Heterozygous missense mutations in the N-terminal motor or coiled-coil domains of the kinesin family member 5A (KIF5A) gene cause monogenic spastic paraplegia (HSP10) and Charcot-Marie-Tooth disease type 2 (CMT2). Moreover, heterozygous de novo frame-shift mutations in the C-terminal domain of KIF5A are associated with neonatal intractable myoclonus, a neurodevelopmental syndrome. These findings, together with the observation that many of the disease genes associated with amyotrophic lateral sclerosis disrupt cytoskeletal function and intracellular transport, led us to hypothesize that mutations in KIF5A are also a cause of amyotrophic lateral sclerosis. Using whole exome sequencing followed by rare variant analysis of 426 patients with familial amyotrophic lateral sclerosis and 6137 control subjects, we detected an enrichment of KIF5A splice-site mutations in amyotrophic lateral sclerosis (2/426 compared to 0/6137 in controls; P = 4.2 × 10-3), both located in a hot-spot in the C-terminus of the protein and predicted to affect splicing exon 27. We additionally show co-segregation with amyotrophic lateral sclerosis of two canonical splice-site mutations in two families. Investigation of lymphoblast cell lines from patients with KIF5A splice-site mutations revealed the loss of mutant RNA expression and suggested haploinsufficiency as the most probable underlying molecular mechanism. Furthermore, mRNA sequencing of a rare non-synonymous missense mutation (predicting p.Arg1007Gly) located in the C-terminus of the protein shortly upstream of the splice donor of exon 27 revealed defective KIF5A pre-mRNA splicing in respective patient-derived cell lines owing to abrogation of the donor site. Finally, the non-synonymous single nucleotide variant rs113247976 (minor allele frequency = 1.00% in controls, n = 6137), also located in the C-terminal region [p.(Pro986Leu) in exon 26], was significantly enriched in familial amyotrophic lateral sclerosis patients (minor allele

Patients with Obesity Caused by Melanocortin-4 Receptor Mutations Can Be Treated with a Glucagon-like Peptide-1 Receptor Agonist

DEFF Research Database (Denmark)

Iepsen, Eva W; Zhang, Jinyi; Thomsen, Henrik S

2018-01-01

Pathogenic mutations in the appetite-regulating melanocortin-4 receptor (MC4R) represent the most common cause of monogenic obesity with limited treatment options. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) cause weight loss by reducing appetite. We assessed the effect of the GLP-1 RA...... liraglutide 3.0 mg for 16 weeks in 14 obese individuals with pathogenic MC4R mutations (BMI 37.5 ± 6.8) and 28 matched control participants without MC4R mutation (BMI 36.8 ± 4.8). Liraglutide decreased body weight by 6.8 kg ± 1.8 kg in individuals with pathogenic MC4R mutations and by 6.1 kg ± 1.2 kg...... in control participants. Total body fat, waist circumference, and fasting and postprandial glucose concentrations similarly decreased in both groups. Thus, liraglutide induced an equal, clinically significant weight loss of 6% in both groups, indicating that the appetite-reducing effect of liraglutide...

Differential causes of mutation and killing in Escherichia coli after psoralen plus light treatment: monoadducts and cross-links

Energy Technology Data Exchange (ETDEWEB)

Seki, T; Nozu, K [Nara Medical Univ., Kashihara (Japan); Kondo, S

1978-01-01

On treatment with 8-methoxypsoralen plus near uv light, an excision (uvrB/sup -/) strain of Escherichia coli showed about 3- and 10 times higher sensitivities to killing and mutation, respectively, than its parental strain. On re-irradiation with near uv in the absence of unbound psoralen, the uvrB/sup -/ strain pretreated with psoralen plus near uv showed a decrease in both survival and mutation. After treatment with psoralen plus near uv, re-irradiation of T7DNA in the absence of unbound psoralen caused an increase in the cross-linked fraction with an equivalent decrease in the non-cross-linked fraction. From these and previous results, it is concluded that monoadducts produced by treatment with psoralen plus near uv are converted to cross-links by further irradiation and that, in E.coli, monoadducts are responsible for the mutation induced by psoralen-plus-light whereas cross-links are the major cause of its lethal action.

Induced mutation in tropical fruit trees

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-05-15

This publication is based on an FAO/IAEA coordinated research project (CRP) and provides insight into the application of induced mutation and in vitro techniques for the improvement of well known fruit trees such as citrus, mango, avocado and papaya, as well as more exotic fruit trees such as litchi, annona, jujube, carambola, pitanga and jaboticaba. The latter are of particular importance due to their adaptation to harsh environments and their high potential as basic food and micronutrient providers for populations in poorer and more remote regions. The findings of the CRP show that application of radiation induced mutation techniques in tropical and subtropical fruit trees can contribute to improving nutritional balance food security, and to enhancing the economic status of growers.

Induced mutation in tropical fruit trees

International Nuclear Information System (INIS)

2009-05-01

This publication is based on an FAO/IAEA coordinated research project (CRP) and provides insight into the application of induced mutation and in vitro techniques for the improvement of well known fruit trees such as citrus, mango, avocado and papaya, as well as more exotic fruit trees such as litchi, annona, jujube, carambola, pitanga and jaboticaba. The latter are of particular importance due to their adaptation to harsh environments and their high potential as basic food and micronutrient providers for populations in poorer and more remote regions. The findings of the CRP show that application of radiation induced mutation techniques in tropical and subtropical fruit trees can contribute to improving nutritional balance food security, and to enhancing the economic status of growers

Structure-Function Correlation Analysis of Connexin50 Missense Mutations Causing Congenital Cataract: Electrostatic Potential Alteration Could Determine Intracellular Trafficking Fate of Mutants

Directory of Open Access Journals (Sweden)

Devroop Sarkar

2014-01-01

Full Text Available Connexin50 (Cx50 mutations are reported to cause congenital cataract probably through the disruption of intercellular transport in the lens. Cx50 mutants that undergo mistrafficking have generally been associated with failure to form functional gap junction channels; however, sometimes even properly trafficked mutants were found to undergo similar consequences. We hereby wanted to elucidate any structural bases of the varied functional consequences of Cx50 missense mutations through in silico approach. Computational studies have been done based on a Cx50 homology model to assess conservation, solvent accessibility, and 3-dimensional localization of mutated residues as well as mutation-induced changes in surface electrostatic potential, H-bonding, and steric clash. This was supplemented with meta-analysis of published literature on the functional properties of connexin missense mutations. Analyses revealed that the mutation-induced critical alterations of surface electrostatic potential in Cx50 mutants could determine their fate in intracellular trafficking. A similar pattern was observed in case of mutations involving corresponding conserved residues in other connexins also. Based on these results the trafficking fates of 10 uncharacterized Cx50 mutations have been predicted. Further experimental analyses are needed to validate the observed correlation.

Is low-energy-ion bombardment generated X-ray emission a secondary mutational source to ion-beam-induced genetic mutation?

Energy Technology Data Exchange (ETDEWEB)

Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Thopan, P.; Yaopromsiri, C. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Suwannakachorn, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

2013-07-15

Highlights: ► Detected X-ray emission from metal, plastic and biological samples. ► Characteristic X-ray emission was detected from metal but not from non-metals. ► Low-energy ion bombarded bacteria held in different sample holders. ► Bacteria held in metal holder had higher mutation rate than in plastic holder. ► Ion-beam-induced X-ray from biological sample is not a basic mutation source. -- Abstract: Low-energy ion beam biotechnology has achieved tremendous successes in inducing crop mutation and gene transfer. However, mechanisms involved in the related processes are not yet well understood. In ion-beam-induced mutation, ion-bombardment-produced X-ray has been proposed to be one of the secondary mutation sources, but the speculation has not yet been experimentally tested. We carried out this investigation to test whether the low-energy ion-beam-produced X-ray was a source of ion-beam-induced mutation. In the investigation, X-ray emission from 29-keV nitrogen- or argon- ion beam bombarded bacterial Escherichia coli (E. coli) cells held in a metal or plastic sample holder was in situ detected using a highly sensitive X-ray detector. The ion beam bombarded bacterial cells held in different material holders were observed for mutation induction. The results led to a conclusion that secondary X-ray emitted from ion-beam-bombarded biological living materials themselves was not a, or at least a negligible, mutational source, but the ion-beam-induced X-ray emission from the metal that made the sample holder could be a source of mutation.

Is low-energy-ion bombardment generated X-ray emission a secondary mutational source to ion-beam-induced genetic mutation?

International Nuclear Information System (INIS)

Thongkumkoon, P.; Prakrajang, K.; Thopan, P.; Yaopromsiri, C.; Suwannakachorn, D.; Yu, L.D.

2013-01-01

Highlights: ► Detected X-ray emission from metal, plastic and biological samples. ► Characteristic X-ray emission was detected from metal but not from non-metals. ► Low-energy ion bombarded bacteria held in different sample holders. ► Bacteria held in metal holder had higher mutation rate than in plastic holder. ► Ion-beam-induced X-ray from biological sample is not a basic mutation source. -- Abstract: Low-energy ion beam biotechnology has achieved tremendous successes in inducing crop mutation and gene transfer. However, mechanisms involved in the related processes are not yet well understood. In ion-beam-induced mutation, ion-bombardment-produced X-ray has been proposed to be one of the secondary mutation sources, but the speculation has not yet been experimentally tested. We carried out this investigation to test whether the low-energy ion-beam-produced X-ray was a source of ion-beam-induced mutation. In the investigation, X-ray emission from 29-keV nitrogen- or argon- ion beam bombarded bacterial Escherichia coli (E. coli) cells held in a metal or plastic sample holder was in situ detected using a highly sensitive X-ray detector. The ion beam bombarded bacterial cells held in different material holders were observed for mutation induction. The results led to a conclusion that secondary X-ray emitted from ion-beam-bombarded biological living materials themselves was not a, or at least a negligible, mutational source, but the ion-beam-induced X-ray emission from the metal that made the sample holder could be a source of mutation

SPATACSIN mutations cause autosomal recessive juvenile amyotrophic lateral sclerosis

OpenAIRE

Orlacchio, Antonio; Babalini, Carla; Borreca, Antonella; Patrono, Clarice; Massa, Roberto; Basaran, Sarenur; Munhoz, Renato P.; Rogaeva, Ekaterina A.; St George-Hyslop, Peter H.; Bernardi, Giorgio; Kawarai, Toshitaka

2010-01-01

The mutation of the spatacsin gene is the single most common cause of autosomal recessive hereditary spastic paraplegia with thin corpus callosum. Common clinical, pathological and genetic features between amyotrophic lateral sclerosis and hereditary spastic paraplegia motivated us to investigate 25 families with autosomal recessive juvenile amyotrophic lateral sclerosis and long-term survival for mutations in the spatascin gene. The inclusion criterion was a diagnosis of clinically definite ...

Founder Fukutin mutation causes Walker-Warburg syndrome in four Ashkenazi Jewish families.

Science.gov (United States)

Chang, Wendy; Winder, Thomas L; LeDuc, Charles A; Simpson, Lynn L; Millar, William S; Dungan, Jeffrey; Ginsberg, Norman; Plaga, Stacey; Moore, Steven A; Chung, Wendy K

2009-06-01

Walker-Warburg syndrome (WWS) is a genetically heterogeneous congenital muscular dystrophy caused by abnormal glycosylation of alpha-dystroglycan (alpha-DG) that is associated with brain malformations and eye anomalies. The Fukutin (FKTN) gene, which causes autosomal recessively inherited WWS is most often associated with Fukuyama congenital muscular dystrophy in Japan. We describe the clinical features of four nonconsanguinous Ashkenazi Jewish families with WWS and identify the underlying genetic basis for WWS. We screened for mutations in POMGnT1, POMT1, POMT2, and FKTN, genes causing WWS, by dideoxy sequence analysis. We identified an identical homozygous c.1167insA mutation in the FKTN gene on a common haplotype in all four families and identified 2/299 (0.7%) carriers for the c.1167insA mutation among normal American Ashkenazi Jewish adults. These data suggest that the c.1167insA FKTN mutation described by us is a founder mutation that can be used to target diagnostic testing and carrier screening in the Ashkenazi Jewish population. Copyright (c) 2009 John Wiley & Sons, Ltd.

Founder Fukutin mutation causes Walker-Warburg syndrome in four Ashkenazi Jewish families†

Science.gov (United States)

Chang, Wendy; Winder, Thomas L.; LeDuc, Charles A.; Simpson, Lynn L.; Millar, William S.; Dungan, Jeffrey; Ginsberg, Norman; Plaga, Stacey; Moore, Steven A.; Chung, Wendy K.

2009-01-01

Objective Walker-Warburg syndrome (WWS) is a genetically heterogeneous congenital muscular dystrophy caused by abnormal glycosylation of α-dystroglycan (α-DG) that is associated with brain malformations and eye anomalies. The Fukutin (FKTN) gene, which causes autosomal recessively inherited WWS is most often associated with Fukuyama congenital muscular dystrophy in Japan. We describe the clinical features of four nonconsanguinous Ashkenazi Jewish families with WWS and identify the underlying genetic basis for WWS. Method We screened for mutations in POMGnT1, POMT1, POMT2, and FKTN, genes causing WWS, by dideoxy sequence analysis. Results We identified an identical homozygous c.1167insA mutation in the FKTN gene on a common haplotype in all four families and identified 2/299 (0.7%) carriers for the c.1167insA mutation among normal American Ashkenazi Jewish adults. Conclusion These data suggest that the c.1167insA FKTN mutation described by us is a founder mutation that can be used to target diagnostic testing and carrier screening in the Ashkenazi Jewish population. PMID:19266496

Spontaneous 8bp Deletion in Nbeal2 Recapitulates the Gray Platelet Syndrome in Mice

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Tomberg, Kärt; Khoriaty, Rami; Westrick, Randal J.; Fairfield, Heather E.; Reinholdt, Laura G.; Brodsky, Gary L.; Davizon-Castillo, Pavel; Ginsburg, David; Di Paola, Jorge

2016-01-01

During the analysis of a whole genome ENU mutagenesis screen for thrombosis modifiers, a spontaneous 8 base pair (bp) deletion causing a frameshift in exon 27 of the Nbeal2 gene was identified. Though initially considered as a plausible thrombosis modifier, this Nbeal2 mutation failed to suppress the synthetic lethal thrombosis on which the original ENU screen was based. Mutations in NBEAL2 cause Gray Platelet Syndrome (GPS), an autosomal recessive bleeding disorder characterized by macrothrombocytopenia and gray-appearing platelets due to lack of platelet alpha granules. Mice homozygous for the Nbeal2 8 bp deletion (Nbeal2gps/gps) exhibit a phenotype similar to human GPS, with significantly reduced platelet counts compared to littermate controls (p = 1.63 x 10−7). Nbeal2gps/gps mice also have markedly reduced numbers of platelet alpha granules and an increased level of emperipolesis, consistent with previously characterized mice carrying targeted Nbeal2 null alleles. These findings confirm previous reports, provide an additional mouse model for GPS, and highlight the potentially confounding effect of background spontaneous mutation events in well-characterized mouse strains. PMID:26950939

Spontaneous 8bp Deletion in Nbeal2 Recapitulates the Gray Platelet Syndrome in Mice.

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Kärt Tomberg

Full Text Available During the analysis of a whole genome ENU mutagenesis screen for thrombosis modifiers, a spontaneous 8 base pair (bp deletion causing a frameshift in exon 27 of the Nbeal2 gene was identified. Though initially considered as a plausible thrombosis modifier, this Nbeal2 mutation failed to suppress the synthetic lethal thrombosis on which the original ENU screen was based. Mutations in NBEAL2 cause Gray Platelet Syndrome (GPS, an autosomal recessive bleeding disorder characterized by macrothrombocytopenia and gray-appearing platelets due to lack of platelet alpha granules. Mice homozygous for the Nbeal2 8 bp deletion (Nbeal2gps/gps exhibit a phenotype similar to human GPS, with significantly reduced platelet counts compared to littermate controls (p = 1.63 x 10-7. Nbeal2gps/gps mice also have markedly reduced numbers of platelet alpha granules and an increased level of emperipolesis, consistent with previously characterized mice carrying targeted Nbeal2 null alleles. These findings confirm previous reports, provide an additional mouse model for GPS, and highlight the potentially confounding effect of background spontaneous mutation events in well-characterized mouse strains.

A Novel Mutation in ERCC8 Gene Causing Cockayne Syndrome

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Maryam Taghdiri

2017-08-01

Full Text Available Cockayne syndrome (CS is a rare autosomal recessive multisystem disorder characterized by impaired neurological and sensory functions, cachectic dwarfism, microcephaly, and photosensitivity. This syndrome shows a variable age of onset and rate of progression, and its phenotypic spectrum include a wide range of severity. Due to the progressive nature of this disorder, diagnosis can be more important when additional signs and symptoms appear gradually and become steadily worse over time. Therefore, mutation analysis of genes involved in CS pathogenesis can be helpful to confirm the suspected clinical diagnosis. Here, we report a novel mutation in ERCC8 gene in a 16-year-old boy who suffers from poor weight gain, short stature, microcephaly, intellectual disability, and photosensitivity. The patient was born to consanguineous family with no previous documented disease in his parents. To identify disease-causing mutation in the patient, whole exome sequencing utilizing next-generation sequencing on an Illumina HiSeq 2000 platform was performed. Results revealed a novel homozygote mutation in ERCC8 gene (NM_000082: exon 11, c.1122G>C in our patient. Another gene (ERCC6, which is also involved in CS did not have any disease-causing mutations in the proband. The new identified mutation was then confirmed by Sanger sequencing in the proband, his parents, and extended family members, confirming co-segregation with the disease. In addition, different bioinformatics programs which included MutationTaster, I-Mutant v2.0, NNSplice, Combined Annotation Dependent Depletion, The PhastCons, Genomic Evolutationary Rate Profiling conservation score, and T-Coffee Multiple Sequence Alignment predicted the pathogenicity of the mutation. Our study identified a rare novel mutation in ERCC8 gene and help to provide accurate genetic counseling and prenatal diagnosis to minimize new affected individuals in this family.

A Novel Mutation in ERCC8 Gene Causing Cockayne Syndrome.

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Taghdiri, Maryam; Dastsooz, Hassan; Fardaei, Majid; Mohammadi, Sanaz; Farazi Fard, Mohammad Ali; Faghihi, Mohammad Ali

2017-01-01

Cockayne syndrome (CS) is a rare autosomal recessive multisystem disorder characterized by impaired neurological and sensory functions, cachectic dwarfism, microcephaly, and photosensitivity. This syndrome shows a variable age of onset and rate of progression, and its phenotypic spectrum include a wide range of severity. Due to the progressive nature of this disorder, diagnosis can be more important when additional signs and symptoms appear gradually and become steadily worse over time. Therefore, mutation analysis of genes involved in CS pathogenesis can be helpful to confirm the suspected clinical diagnosis. Here, we report a novel mutation in ERCC8 gene in a 16-year-old boy who suffers from poor weight gain, short stature, microcephaly, intellectual disability, and photosensitivity. The patient was born to consanguineous family with no previous documented disease in his parents. To identify disease-causing mutation in the patient, whole exome sequencing utilizing next-generation sequencing on an Illumina HiSeq 2000 platform was performed. Results revealed a novel homozygote mutation in ERCC8 gene (NM_000082: exon 11, c.1122G>C) in our patient. Another gene ( ERCC6 ), which is also involved in CS did not have any disease-causing mutations in the proband. The new identified mutation was then confirmed by Sanger sequencing in the proband, his parents, and extended family members, confirming co-segregation with the disease. In addition, different bioinformatics programs which included MutationTaster, I-Mutant v2.0, NNSplice, Combined Annotation Dependent Depletion, The PhastCons, Genomic Evolutationary Rate Profiling conservation score, and T-Coffee Multiple Sequence Alignment predicted the pathogenicity of the mutation. Our study identified a rare novel mutation in ERCC8 gene and help to provide accurate genetic counseling and prenatal diagnosis to minimize new affected individuals in this family.

Modifying effect of 5-fluoro-2-deoxiuridine on the frequency of x-ray-induced visible mutations in wheat

International Nuclear Information System (INIS)

Azatyan, R.A.; Avakyan, V.A.

1985-01-01

A modifying effect of FUDR on the output of visible mutations induced by X-ray radiation has been studied at soft fall wheat (Tr. aestivum var. turcicum). It is shown that at X-ray radiation of dry seeds with subsequent treatment of FUDR increased is the mutant percent in M 3 which has constituted 0.61% at irradiation in dose of 100 Gy ad 1.03% at irradiation by the same dose and FUDR influence during 10 hours. In analogous variants at irradiation by 150 Gi dose the mutation frequency reached 1.47 and 2.07% respectively. It is shown that FUDR postradiation treatment promotes not only the increase of frequency but consderablly widens the spectrum of induced mutations. A supposition is made that FUDR modyfying effect is caused by DNA synthesis inhibition. A problem is discussed on a possible realization of potential DNA changes caused by irradiation, at additional influence of inhibitor

Induced skeletal mutations

International Nuclear Information System (INIS)

Selby, P.B.

1979-01-01

This paper describes a large-scale experiment that, by means of breeding tests, confirmed that many dominant skeletal mutations are induced by large-dose radiation exposure. The author also discusses: (1) the major advantages and disadvantages of the skeletal method in improving estimates of genetic hazard to man; (2) future uses of the skeletal method; (3) direct estimation of risk beyond the first generation using the skeletal method; and (4) the possibility of using the skeletal method as a quick and easy screen for chemical mutagens

Occurrence of mutations in the epidermal growth factor receptor gene in X-ray-induced rat lung tumors

International Nuclear Information System (INIS)

Kitahashi, Tsukasa; Takahashi, Mami; Yamada, Yutaka

2008-01-01

Epidermal growth factor receptor (EGFR) gene alterations have been found in human lung cancers. However, there is no information on the factors inducing EGFR mutations. In rodents, K-ras mutations are frequently found in many lung carcinogenesis models, but hitherto, Egfr mutations have not been reported. Their presence was therefore investigated in representative lung carcinogenesis models with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosobis(2-hydroxypropyl)amine (BHP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MelQx) and ethyl carbamate (urethane), as well as X-ray irradiation. With the chemical carcinogenesis models, no mutations were detected in Egfr, which is in clear contrast to the high rates observed in either codon 12 or 61 of K-ras (21/23 of the lung tumors induced with NNK, 4/5 with MelQx, 1/4 with urethane and 7/18 with BHP). However, in the X-ray-induced lung tumors, Egfr mutations with amino acid substitution were observed in exons 18 and 21 (4/12, 33%), but no activating mutation of K-ras was detected. In addition, one and four silent mutations were identified in K-ras (exon 1) and Egfr (exons 18, 20 and 21), respectively. Most mutations in both Egfr and K-ras were G/C→A/T transitions (7/8, 88% and 31/34, 91%, respectively). Although, the mutational patterns in equivalent human lesions were not completely coincident, this first report of Egfr mutations in an experimental lung tumor model suggests that X-rays or other factors producing oxygen radicals could cause EGFR mutations in some proportion of lung cancers in humans. (author)

LRIG2 mutations cause urofacial syndrome.

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Stuart, Helen M; Roberts, Neil A; Burgu, Berk; Daly, Sarah B; Urquhart, Jill E; Bhaskar, Sanjeev; Dickerson, Jonathan E; Mermerkaya, Murat; Silay, Mesrur Selcuk; Lewis, Malcolm A; Olondriz, M Beatriz Orive; Gener, Blanca; Beetz, Christian; Varga, Rita E; Gülpınar, Omer; Süer, Evren; Soygür, Tarkan; Ozçakar, Zeynep B; Yalçınkaya, Fatoş; Kavaz, Aslı; Bulum, Burcu; Gücük, Adnan; Yue, Wyatt W; Erdogan, Firat; Berry, Andrew; Hanley, Neil A; McKenzie, Edward A; Hilton, Emma N; Woolf, Adrian S; Newman, William G

2013-02-07

Urofacial syndrome (UFS) (or Ochoa syndrome) is an autosomal-recessive disease characterized by congenital urinary bladder dysfunction, associated with a significant risk of kidney failure, and an abnormal facial expression upon smiling, laughing, and crying. We report that a subset of UFS-affected individuals have biallelic mutations in LRIG2, encoding leucine-rich repeats and immunoglobulin-like domains 2, a protein implicated in neural cell signaling and tumorigenesis. Importantly, we have demonstrated that rare variants in LRIG2 might be relevant to nonsyndromic bladder disease. We have previously shown that UFS is also caused by mutations in HPSE2, encoding heparanase-2. LRIG2 and heparanase-2 were immunodetected in nerve fascicles growing between muscle bundles within the human fetal bladder, directly implicating both molecules in neural development in the lower urinary tract. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

In silico investigation of molecular effects caused by missense mutations in creatine transporter protein

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Zhang, Zhe; Schwatz, Charles; Alexov, Emil

2011-03-01

Creatine transporter (CT) protein, which is encoded by SLC6A8 gene, is essential for taking up the creatine in the cell, which in turn plays a key role in the spatial and temporal maintenance of energy in skeletal and cardiac muscle cells. It was shown that some missense mutations in CT cause mental retardation, while others are harmless non-synonymous single nucleoside polymorphism (nsSNP). Currently fifteen missense mutations in CT are known, among which twelve are disease-causing. Sequence analysis reveals that there is no clear trend distinguishing disease-causing from harmless missense mutations. Because of that, we built 3D model of the CT using highly homologous template and use the model to investigate the effects of mutations of CT stability and hydrogen bond network. It is demonstrated that disease-causing mutations affect the folding free energy and ionization states of titratable group in much greater extend as compared with harmless mutations. Supported by grants from NLM, NIH, grant numbers 1R03LM009748 and 1R03LM009748-S1.

Phenotypic Variability of Osteogenesis Imperfecta Type V Caused by an IFITM5 Mutation

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Shapiro, Jay R; Lietman, Caressa; Grover, Monica; Lu, James T; Nagamani, Sandesh CS; Dawson, Brian C; Baldridge, Dustin M; Bainbridge, Matthew N; Cohn, Dan H; Blazo, Maria; Roberts, Timothy T; Brennen, Feng-Shu; Wu, Yimei; Gibbs, Richard A; Melvin, Pamela; Campeau, Philippe M; Lee, Brendan H

2013-01-01

In a large cohort of osteogenesis imperfecta type V (OI type V) patients (17 individuals from 12 families), we identified the same mutation in the 5′ untranslated region (5′UTR) of the interferon-induced transmembrane protein 5 (IFITM5) gene by whole exome and Sanger sequencing (IFITM5 c.–14C > T) and provide a detailed description of their phenotype. This mutation leads to the creation of a novel start codon adding five residues to IFITM5 and was recently reported in several other OI type V families. The variability of the phenotype was quite large even within families. Whereas some patients presented with the typical calcification of the forearm interosseous membrane, radial head dislocation and hyperplastic callus (HPC) formation following fractures, others had only some of the typical OI type V findings. Thirteen had calcification of interosseous membranes, 14 had radial head dislocations, 10 had HPC, 9 had long bone bowing, 11 could ambulate without assistance, and 1 had mild unilateral mixed hearing loss. The bone mineral density varied greatly, even within families. Our study thus highlights the phenotypic variability of OI type V caused by the IFITM5 mutation. PMID:23408678

Molecular analysis of carbon ion-induced mutations in Arabidopsis thaliana

International Nuclear Information System (INIS)

Shikazono, Naoya; Tanaka, Atsushi; Watanabe, Hiroshi; Tano, Shigemitsu; Yokota, Yukihiko

1998-01-01

In order to elucidate the characteristics of the mutations induced by ion particles at the molecular level in plants, mutated loci in carbon ion-induced mutants of Arabidopsis were investigated by PCR and Southern blot analyses. In the present study, two lines of gl1 mutant and two lines of tt4 mutant were isolated after carbon ion-irradiation. Out of four mutants, one had a deletion, other two contained rearrangements, and one had a point-like mutation. From the present result, it was suggested that ion particles induced different kinds of alterations of the DNA and therefore they could produce various types of mutant alleles in plants. (author)

Progranulin mutation causes frontotemporal dementia in the Swedish Karolinska family.

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Chiang, Huei-Hsin; Rosvall, Lina; Brohede, Jesper; Axelman, Karin; Björk, Behnosh F; Nennesmo, Inger; Robins, Tiina; Graff, Caroline

2008-11-01

Frontotemporal dementia (FTD) is a neurodegenerative disease characterized by cognitive impairment, language dysfunction, and/or changes in personality. Recently it has been shown that progranulin (GRN) mutations can cause FTD as well as other neurodegenerative phenotypes. DNA from 30 family members, of whom seven were diagnosed with FTD, in the Karolinska family was available for GRN sequencing. Fibroblast cell mRNA from one affected family member and six control individuals was available for relative quantitative real-time polymerase chain reaction to investigate the effect of the mutation. Furthermore, the cDNA of an affected individual was sequenced. Clinical and neuropathologic findings of a previously undescribed family branch are presented. A frameshift mutation in GRN (g.102delC) was detected in all affected family members and absent in four unaffected family members older than 70 years. Real-time polymerase chain reaction data showed an approximately 50% reduction of GRN fibroblast mRNA in an affected individual. The mutated mRNA transcripts were undetectable by cDNA sequencing. Segregation and RNA analyses showed that the g.102delC mutation, previously reported, causes FTD in the Karolinska family. Our findings add further support to the significance of GRN in FTD etiology and the presence of modifying genes, which emphasize the need for further studies into the mechanisms of clinical heterogeneity. However, the results already call for attention to the complexity of predictive genetic testing of GRN mutations.

Gamma radiation-induced heritable mutations at repetitive DNA loci in out-bred mice

International Nuclear Information System (INIS)

Somers, C.M.; Sharma, R.; Quinn, J.S.; Boreham, D.R.

2004-01-01

Recent studies have shown that expanded-simple-tandem-repeat (ESTR) DNA loci are efficient genetic markers for detecting radiation-induced germ line mutations in mice. Dose responses following irradiation, however, have only been characterized in a small number of inbred mouse strains, and no studies have applied Esters to examine potential modifiers of radiation risk, such as adaptive response. We gamma-irradiated groups of male out-bred Swiss-Webster mice with single acute doses of 0.5 and 1.0 Gy, and compared germ line mutation rates at ESTR loci to a sham-irradiated control. To test for evidence of adaptive response we treated a third group with a total dose of 1.1 Gy that was fractionated into a 0.1 Gy adapting dose, followed by a challenge dose of 1.0 Gy 24 h later. Paternal mutation rates were significantly elevated above the control in the 0.5 Gy (2.8-fold) and 1.0 Gy (3.0-fold) groups, but were similar to each other despite the difference in radiation dose. The doubling dose for paternal mutation induction was 0.26 Gy (95% CI = 0.14-0.51 Gy). Males adapted with a 0.1 Gy dose prior to a 1.0 Gy challenge dose had mutation rates that were not significantly elevated above the control, and were 43% reduced compared to those receiving single doses. We conclude that pre-meiotic male germ cells in out-bred Swiss-Webster mice are sensitive to ESTR mutations induced by acute doses of ionizing radiation, but mutation induction may become saturated at a lower dose than in some strains of inbred mice. Reduced mutation rates in the adapted group provide intriguing evidence for suppression of ESTR mutations in the male germline through adaptive response. Repetitive DNA markers may be useful tools for exploration of biological factors affecting the probability of heritable mutations caused by low-dose ionizing radiation exposure. The biological significance of ESTR mutations in terms of radiation risk assessment, however, is still undetermined

A novel STXBP1 mutation causes typical Rett syndrome in a Japanese girl.

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Yuge, Kotaro; Iwama, Kazuhiro; Yonee, Chihiro; Matsufuji, Mayumi; Sano, Nozomi; Saikusa, Tomoko; Yae, Yukako; Yamashita, Yushiro; Mizuguchi, Takeshi; Matsumoto, Naomichi; Matsuishi, Toyojiro

2018-06-01

Rett syndrome (RTT) is a neurodevelopmental disorder mostly caused by mutations in Methyl-CpG-binding protein 2 (MECP2); however, mutations in various other genes may lead to RTT-like phenotypes. Here, we report the first case of a Japanese girl with RTT caused by a novel syntaxin-binding protein 1 (STXBP1) frameshift mutation (c.60delG, p.Lys21Argfs*16). She showed epilepsy at one year of age, regression of acquired psychomotor abilities thereafter, and exhibited stereotypic hand and limb movements at 3 years of age. Her epilepsy onset was earlier than is typical for RTT patients. However, she fully met the 2010 diagnostic criteria of typical RTT. STXBP1 mutations cause early infantile epileptic encephalopathy (EIEE), various intractable epilepsies, and neurodevelopmental disorders. However, the case described here presented a unique clinical presentation of typical RTT without EIEE and a novel STXBP1 mutation. Copyright © 2018 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Detection of induced male germline mutation: Correlations and comparisons between traditional germline mutation assays, transgenic rodent assays and expanded simple tandem repeat instability assays

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Singer, Timothy M. [Mutagenesis Section, Environmental and Occupational Toxicology Division, Safe Environments Programme, 0803A, Health Canada, Ottawa, Ont., K1A 0K9 (Canada); Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ont., K1S 5B6 (Canada); Lambert, Iain B. [Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ont., K1S 5B6 (Canada); Williams, Andrew [Biostatistics and Epidemiology Division, Safe Environments Programme, 6604B, Health Canada, Ottawa, Ont., K1A 0K9 (Canada); Douglas, George R. [Mutagenesis Section, Environmental and Occupational Toxicology Division, Safe Environments Programme, 0803A, Health Canada, Ottawa, Ont., K1A 0K9 (Canada); Yauk, Carole L. [Mutagenesis Section, Environmental and Occupational Toxicology Division, Safe Environments Programme, 0803A, Health Canada, Ottawa, Ont., K1A 0K9 (Canada)]. E-mail: carole_yauk@hc-sc.gc.ca

2006-06-25

Several rodent assays are capable of monitoring germline mutation. These include traditional assays, such as the dominant lethal (DL) assay, the morphological specific locus (SL) test and the heritable translocation (HT) assay, and two assays that have been developed more recently-the expanded simple tandem repeat (ESTR) and transgenic rodent (TGR) mutation assays. In this paper, we have compiled the limited amount of experimental data that are currently available to make conclusions regarding the comparative ability of the more recently developed assays to detect germline mutations induced by chemical and radiological agents. The data suggest that ESTR and TGR assays are generally comparable with SL in detecting germline mutagenicity induced by alkylating agents and radiation, though TGR offered less sensitivity than ESTR in some cases. The DL and HT assays detect clastogenic events and are most susceptible to mutations arising in post-spermatogonial cells, and they may not provide the best comparisons with TGR and ESTR instability. The measurement of induced ESTR instability represents a relatively sensitive method of identifying agents causing germline mutation in rodents, and may also be useful for bio-monitoring exposed individuals in the human population. Any future use of the TGR and ESTR germline mutation assays in a regulatory testing context will entail more robust and extensive characterization of assay performance. This will require substantially more data, including experiments measuring multiple endpoints, a greatly expanded database of chemical agents and a focus on characterizing stage-specific activity of mutagens in these assays, preferably by sampling epididymal sperm exposed at defined pre-meiotic, meiotic and post-meiotic stages of development.

Detection of induced male germline mutation: Correlations and comparisons between traditional germline mutation assays, transgenic rodent assays and expanded simple tandem repeat instability assays

International Nuclear Information System (INIS)

Singer, Timothy M.; Lambert, Iain B.; Williams, Andrew; Douglas, George R.; Yauk, Carole L.

2006-01-01

Several rodent assays are capable of monitoring germline mutation. These include traditional assays, such as the dominant lethal (DL) assay, the morphological specific locus (SL) test and the heritable translocation (HT) assay, and two assays that have been developed more recently-the expanded simple tandem repeat (ESTR) and transgenic rodent (TGR) mutation assays. In this paper, we have compiled the limited amount of experimental data that are currently available to make conclusions regarding the comparative ability of the more recently developed assays to detect germline mutations induced by chemical and radiological agents. The data suggest that ESTR and TGR assays are generally comparable with SL in detecting germline mutagenicity induced by alkylating agents and radiation, though TGR offered less sensitivity than ESTR in some cases. The DL and HT assays detect clastogenic events and are most susceptible to mutations arising in post-spermatogonial cells, and they may not provide the best comparisons with TGR and ESTR instability. The measurement of induced ESTR instability represents a relatively sensitive method of identifying agents causing germline mutation in rodents, and may also be useful for bio-monitoring exposed individuals in the human population. Any future use of the TGR and ESTR germline mutation assays in a regulatory testing context will entail more robust and extensive characterization of assay performance. This will require substantially more data, including experiments measuring multiple endpoints, a greatly expanded database of chemical agents and a focus on characterizing stage-specific activity of mutagens in these assays, preferably by sampling epididymal sperm exposed at defined pre-meiotic, meiotic and post-meiotic stages of development

Autosomal dominant familial neurohypophyseal diabetes insipidus caused by a mutation in the arginine-vasopressin II gene in four generations of a Korean family

Directory of Open Access Journals (Sweden)

Myo-Jing Kim

2014-12-01

Full Text Available Autosomal dominant neurohypophyseal diabetes insipidus is a rare form of central diabetes insipidus that is caused by mutations in the vasopressin-neurophysin II (AVP-NPII gene. It is characterized by persistent polydipsia and polyuria induced by deficient or absent secretion of arginine vasopressin (AVP. Here we report a case of familial neurohypophyseal diabetes insipidus in four generations of a Korean family, caused by heterozygous missense mutation in exon 2 of the AVP-NPII gene (c.286G>T. This is the first report of such a case in Korea.

Advances and prospects for induced mutation breeding in Helongjiang Province

International Nuclear Information System (INIS)

Sun Guangzu

1995-12-01

Induced mutation breeding employed on soybean, spring wheat, maize, millet, fiber flax, chinese cabbage, kidney been and garlic in Heilongjiang province. Thirty-six new varieties had introduced and released from 1980 to 1994, made up 20.6% of total released varieties for the same period, accumulated cultivated area of 3.746 million hm 2 , and increased the income of formers to US dollar 168 million; 72 mutants having specific and utilizing values and traits have also been bred in the province. Basic research such as radiation breeding in combination with distant hybridization, biotechnology, and application new induced factors, improving selection methods, have been achieved; 91 articles have been published. These researches play an important role for increasing induced mutation breeding. Three items of suggestion to develop induced mutation breeding are made. (1 tab.)

Novel FAM20A mutation causes autosomal recessive amelogenesis imperfecta.

Science.gov (United States)

Volodarsky, Michael; Zilberman, Uri; Birk, Ohad S

2015-06-01

To relate the peculiar phenotype of amelogenesis imperfecta in a large Bedouin family to the genotype determined by whole genome linkage analysis. Amelogenesis imperfecta (AI) is a broad group of inherited pathologies affecting enamel formation, characterized by variability in phenotypes, causing mutations and modes of inheritance. Autosomal recessive or compound heterozygous mutations in FAM20A, encoding sequence similarity 20, member A, have been shown to cause several AI phenotypes. Five members from a large consanguineous Bedouin family presented with hypoplastic amelogenesis imperfecta with unerupted and resorbed permanent molars. Following Soroka Medical Center IRB approval and informed consent, blood samples were obtained from six affected offspring, five obligatory carriers and two unaffected siblings. Whole genome linkage analysis was performed followed by Sanger sequencing of FAM20A. The sequencing unravelled a novel homozygous deletion mutation in exon 11 (c.1523delC), predicted to insert a premature stop codon (p.Thr508Lysfs*6). We provide an interesting case of novel mutation in this rare disorder, in which the affected kindred is unique in the large number of family members sharing a similar phenotype. Copyright © 2015 Elsevier Ltd. All rights reserved.

Current study on ionizing radiation-induced mitochondial DNA damage and mutations

International Nuclear Information System (INIS)

Zhou Xin; Wang Zhenhua; Zhang Hong

2012-01-01

Current advance in ionizing radiation-induced mitochondrial DNA damage and mutations is reviewed, in addition with the essential differences between mtDNA and nDNA damage and mutations. To extent the knowledge about radiation induced mitochondrial alterations, the researchers in Institute of Modern Physics, Chinese Academy of Sciences developed some technics such as real-time PCR, long-PCR for accurate quantification of radiation induced damage and mutations, and in-depth investigation about the functional changes of mitochondria based on mtDNA damage and mutations were also carried out. In conclusion, the important role of mitochondrial study in radiation biology is underlined, and further study on mitochondrial study associated with late effect and metabolism changes in radiation biology is pointed out. (authors)

CAV3 mutations causing exercise intolerance, myalgia and rhabdomyolysis: Expanding the phenotypic spectrum of caveolinopathies.

Science.gov (United States)

Scalco, Renata Siciliani; Gardiner, Alice R; Pitceathly, Robert D S; Hilton-Jones, David; Schapira, Anthony H; Turner, Chris; Parton, Matt; Desikan, Mahalekshmi; Barresi, Rita; Marsh, Julie; Manzur, Adnan Y; Childs, Anne-Marie; Feng, Lucy; Murphy, Elaine; Lamont, Phillipa J; Ravenscroft, Gianina; Wallefeld, William; Davis, Mark R; Laing, Nigel G; Holton, Janice L; Fialho, Doreen; Bushby, Kate; Hanna, Michael G; Phadke, Rahul; Jungbluth, Heinz; Houlden, Henry; Quinlivan, Ros

2016-08-01

Rhabdomyolysis is often due to a combination of environmental trigger(s) and genetic predisposition; however, the underlying genetic cause remains elusive in many cases. Mutations in CAV3 lead to various neuromuscular phenotypes with partial overlap, including limb girdle muscular dystrophy type 1C (LGMD1C), rippling muscle disease, distal myopathy and isolated hyperCKemia. Here we present a series of eight patients from seven families presenting with exercise intolerance and rhabdomyolysis caused by mutations in CAV3 diagnosed by next generation sequencing (NGS) (n = 6). Symptoms included myalgia (n = 7), exercise intolerance (n = 7) and episodes of rhabdomyolysis (n = 2). Percussion-induced rapid muscle contractions (PIRCs) were seen in five out of six patients examined. A previously reported heterozygous mutation in CAV3 (p.T78M) and three novel variants (p.V14I, p.F41S, p.F54V) were identified. Caveolin-3 immunolabeling in muscle was normal in 3/4 patients; however, immunoblotting showed more than 50% reduction of caveolin-3 in five patients compared with controls. This case series demonstrates that exercise intolerance, myalgia and rhabdomyolysis may be caused by CAV3 mutations and broadens the phenotypic spectrum of caveolinopathies. In our series, immunoblotting was a more sensitive method to detect reduced caveolin-3 levels than immunohistochemistry in skeletal muscle. Patients presenting with muscle pain, exercise intolerance and rhabdomyolysis should be routinely tested for PIRCs as this may be an important clinical clue for caveolinopathies, even in the absence of other "typical" features. The use of NGS may expand current knowledge concerning inherited diseases, and unexpected/atypical phenotypes may be attributed to well-known human disease genes. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of smoke and tea on radiation-induced bone marrow cell mutation and marrow inhibition

International Nuclear Information System (INIS)

Gao Yong; Zhang Weiguang

2004-01-01

Objective: To provide scientific information for the prevention and treatment of the radiation damage by analyzing the effects of smoke and tea on radiation-induced bone marrow cell mutation and marrow inhibition. Methods: 7 group mice were exposed to smoke and/or tea and/or radiation respectively. There were also b blank control group and a cyclophosphamide positive control group. The frequencies of micronucleated polychromatic erythrocytes (MPCE), the ratio of polychromatic erythrocytes (PCE) to mature erythrocytes (RBC) in marrow, and the count of peripheral blood hemoleukocyte were observed. Results: The frequencies of MPCE in the groups irradiated with γ-rays were significantly higher than that in the blank control group (P<0.05 or 0.01). The smoke + radiation group's frequency was significantly higher than single radiation group (P<0.05). The ratios of PCE to RBC in the groups irradiated were significantly lower than that in the blank control group (P<0.01). The counts of peripheral blood hemoleukocyte in the groups irradiated were significantly lower than the blank control group (P<0.01). Conclusion: Radiation were able to cause marrow cell mutation and induce marrow inhibition. Smoke increases the effect of radiation-induced marrow cell mutation. Tea and smoke could not affect radiation-induced bone marrow inhibition

Familial gigantism caused by an NSD1 mutation.

NARCIS (Netherlands)

Haelst, M.M. van; Hoogeboom, J.J.; Baujat, G.; Bruggenwirth, H.T.; Laar, I. van de; Coleman, K.; Rahman, N.; Niermeijer, M.F.; Drop, S.L.; Scambler, P.J.

2005-01-01

A three-generation family with autosomal dominant segregation of a novel NSD1 mutation (6605G --> A, resulting in Cys2202Tyr) is reported. Haploinsufficiency of NSD1 has been identified as the major cause of Sotos syndrome. The overgrowth condition (MIM 117550) is characterized by facial anomalies,

Congenital myopathy is caused by mutation of HACD1.

Science.gov (United States)

Muhammad, Emad; Reish, Orit; Ohno, Yusuke; Scheetz, Todd; Deluca, Adam; Searby, Charles; Regev, Miriam; Benyamini, Lilach; Fellig, Yakov; Kihara, Akio; Sheffield, Val C; Parvari, Ruti

2013-12-20

Congenital myopathies are heterogeneous inherited diseases of muscle characterized by a range of distinctive histologic abnormalities. We have studied a consanguineous family with congenital myopathy. Genome-wide linkage analysis and whole-exome sequencing identified a homozygous non-sense mutation in 3-hydroxyacyl-CoA dehydratase 1 (HACD1) in affected individuals. The mutation results in non-sense mediated decay of the HACD1 mRNA to 31% of control levels in patient muscle and completely abrogates the enzymatic activity of dehydration of 3-hydroxyacyl-CoA, the third step in the elongation of very long-chain fatty acids (VLCFAs). We describe clinical findings correlated with a deleterious mutation in a gene not previously known to be associated with congenital myopathy in humans. We suggest that the mutation in the HACD1 gene causes a reduction in the synthesis of VLCFAs, which are components of membrane lipids and participants in physiological processes, leading to congenital myopathy. These data indicate that HACD1 is necessary for muscle function.

International symposium on induced mutations in plants (ISIM). Book of abstracts

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

The year 2008 will mark the 80th anniversary of mutation induction in crop plants. The application of mutation techniques, i.e. gamma rays and other physical and chemical mutagens, has generated a vast amount of genetic variability and has played a significant role in plant breeding and genetic studies. The widespread use of induced mutants in plant breeding programmes throughout the world has led to the official release of more than 2600 mutant crop varieties. A large number of these varieties (including cereals, pulses, oil, root and tuber crops, and ornamentals) have been released in developing countries, resulting in enormous positive economic impacts. The International Symposium on Induced Mutations in Plants (ISIM) will be the eighth in the Joint FAO/IAEA Programme's Symposium series dedicated exclusively to harnessing and disseminating information on current trends in induced mutagenesis in plants, the first of which was held in 1969 and the last in 1995. These previous symposia dealt with themes relating to the development of efficient protocols for induced mutagenesis and their role in the enhancement of quality traits, as well as resistance to biotic and abiotic stresses in crops and the integration of in vitro and molecular genetic techniques in mutation induction. Since 1995, there has been an increased interest within the scientific community, not only in the use of induced mutations for developing improved crop varieties and for the discovery of genes controlling important traits and in the understanding the functions and mechanisms of actions of these genes, but also in deciphering the biological nature of DNA damage, repair and mutagenesis. A symposium that brings together the key players in basic research, as well as in the development and application of technologies relating to the efficient use of induced mutations for crop improvement and empirical genetic studies, is therefore justified and necessary. Topics addressed at the symposium

Induced plasmon mutations affecting the growth habit of peanuts, A. hypogaea L

International Nuclear Information System (INIS)

Levy, A.; Ashri, A.

1978-01-01

The effectiveness of the acridines ethidium bromide (EB) and acriflavine in inducing plasmon mutations was compared with the alkylating agents ethyl methanesulphonate (EMS) and diethyl sulphate and to γ-rays. The growth habit (trailing versus bunch) of peanuts (A. hypogaea), controlled by genic-cytoplasmic interactions, was utilized. Breeding tests distinguishing nuclear from plasmon mutations were developed and are described in detail. Plasmon mutations were induced, but there were differences in mutation yields between the cultivars and the mutagens. (Auth.)

Germinal mosaicism of PAX3 mutation caused Waardenburg syndrome type I.

Science.gov (United States)

Chen, Kaitian; Zhan, Yuan; Wu, Xuan; Zong, Ling; Jiang, Hongyan

2018-01-01

Waardenburg syndrome mutations are most often recurrent or de novo. The rate of familial recurrence is low and families with several affected children are extremely rare. In this study, we aimed to clarify the underlying hereditary cause of Waardenburg syndrome type I in two siblings in a Chinese family, with a mother affected by prelingual mild hearing loss and a father who was negative for clinical symptoms of Waardenburg syndrome and had a normal hearing threshold. Complete characteristic features of the family members were recorded and genetic sequencing and parent-child relationship analyses were performed. The two probands were found to share double mutations in the PAX3/GJB2 genes that caused concurrent hearing loss in Waardenburg syndrome type I. Their mother carried the GJB2 c.109G > A homozygous mutation; however, neither the novel PAX3 c.592delG mutation, nor the Waardenburg syndrome phenotype, was observed in either parent. These previously unreported digenic mutations in PAX3/GJB2 resulted in deafness associated with Waardenburg syndrome type I in this family. To our knowledge, this is the first report describing germinal mosaicism in Waardenburg syndrome. This concept is important because it complicates genetic counseling of this family regarding the risk of recurrence of the mutations in subsequent pregnancies. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of spermine on spontaneous and UV-induced mutations in Schizosaccharomyces pombe

International Nuclear Information System (INIS)

Prendergast, J.A.; Kamra, O.P.; Nasim, A.

1984-01-01

The effect of different concentrations of spermine on spontaneous and UV-induced mutation in the adenine forward mutation system of Schizosaccharomyces pombe was investigated. The effect of spermine on spontaneous mutation was studied in 5 mutator strains (mut 1-4, mut 1-23, mut 2-9, mut 2-20 and mut 3-21) and on UV-induced mutation in a pigmented adenine-requiring strain and its radiation-sensitive derivative (rad 13). The effect of spermine exposure on mutation induction before and after UV irradiation was also investigated. Spermine increased spontaneous forward mutation in the mut 1-4 strain by 47% and enhanced UV-induced forward mutation 2-fold in the rad 13 and normal pigmented strains. No antimutagenic effect of spermine was seen in any of the strains tested. This is in marked contrast to the antimutagenic effect of spermine observed with bacteria. (Auth.)

Novel USH2A compound heterozygous mutations cause RP/USH2 in a Chinese family.

Science.gov (United States)

Liu, Xiaowen; Tang, Zhaohui; Li, Chang; Yang, Kangjuan; Gan, Guanqi; Zhang, Zibo; Liu, Jingyu; Jiang, Fagang; Wang, Qing; Liu, Mugen

2010-03-17

To identify the disease-causing gene in a four-generation Chinese family affected with retinitis pigmentosa (RP). Linkage analysis was performed with a panel of microsatellite markers flanking the candidate genetic loci of RP. These loci included 38 known RP genes. The complete coding region and exon-intron boundaries of Usher syndrome 2A (USH2A) were sequenced with the proband DNA to screen the disease-causing gene mutation. Restriction fragment length polymorphism (RFLP) analysis and direct DNA sequence analysis were done to demonstrate co-segregation of the USH2A mutations with the family disease. One hundred normal controls were used without the mutations. The disease-causing gene in this Chinese family was linked to the USH2A locus on chromosome 1q41. Direct DNA sequence analysis of USH2A identified two novel mutations in the patients: one missense mutation p.G1734R in exon 26 and a splice site mutation, IVS32+1G>A, which was found in the donor site of intron 32 of USH2A. Neither the p.G1734R nor the IVS32+1G>A mutation was found in the unaffected family members or the 100 normal controls. One patient with a homozygous mutation displayed only RP symptoms until now, while three patients with compound heterozygous mutations in the family of study showed both RP and hearing impairment. This study identified two novel mutations: p.G1734R and IVS32+1G>A of USH2A in a four-generation Chinese RP family. In this study, the heterozygous mutation and the homozygous mutation in USH2A may cause Usher syndrome Type II or RP, respectively. These two mutations expand the mutant spectrum of USH2A.

Recurring dominant-negative mutations in the AVP-NPII gene cause neurohypophyseal diabetes insipidus

Energy Technology Data Exchange (ETDEWEB)

Repaske, D.R. [Children`s Hospital Medical Center, Cincinnati, OH (United States); Phillips, J.A.; Krishnamani, M.R.S. [Vanderbilt Univ. School of Medicine, Nashville, TN (United States)] [and others

1994-09-01

Autosomal dominant neurohypophyseal diabetes insipidus (ADNDI) is a familial form of arginine vasopressin (or antidiuretic hormone) deficiency that is usually manifest in early childhood with polyuria, polydipsia and an antidiuretic response to exogenous vasopressin or its analogs. The phenotype is postulated to arise from gliosis and depletion of the magnocellular neurons that produce vasopressin in the supraoptic and paraventricular nuclei of the hypothalamus. ADNDI is caused by heterozygosity for a variety of mutations in the AVP-NPII gene which encodes vasopressin, its carrier protein (NPII) and a glycoprotein (copeptin) of unknown function. These mutations include: (1) Ala 19{r_arrow}Thr (G279A) in AVP`s signal peptide, (2) Gly 17{r_arrow}Val (G1740T), (3) Pro 24{r_arrow}Leu (C1761T), (4) Gly 57{r_arrow}Ser (G1859A) and (5) del Glu 47({delta}AGG 1824-26), all of which occur in NPII. In characterizing the AVP-NPII mutations in five non-related ADNDI kindreds, we have detected two kindreds having mutation 1 (G279A), two having mutation 3 (C1761T) and one having mutation 4 (G1859A) without any other allelic changes being detected. Two of these recurring mutations (G279A and G1859A) are transitions that occur at CpG dinucleotides while the third (C1761T) does not. Interestingly, families with the same mutations differed in their ethnicity or in their affected AVP-NPII allele`s associated haplotype of closely linked DNA polymorphisms. Our data indicated that at least three of five known AVP-NPII mutations causing ADNDI tend to recur but the mechanisms by which these dominant-negative mutations cause variable or progressive expression of the ADNDI phenotype remain unclear.

A restricted spectrum of NRAS mutations causes Noonan syndrome

NARCIS (Netherlands)

Cirstea, Ion C.; Kutsche, Kerstin; Dvorsky, Radovan; Gremer, Lothar; Carta, Claudio; Horn, Denise; Roberts, Amy E.; Lepri, Francesca; Merbitz-Zahradnik, Torsten; Koenig, Rainer; Kratz, Christian P.; Pantaleoni, Francesca; Dentici, Maria L.; Joshi, Victoria A.; Kucherlapati, Raju S.; Mazzanti, Laura; Mundlos, Stefan; Patton, Michael A.; Silengo, Margherita Cirillo; Rossi, Cesare; Zampino, Giuseppe; Digilio, Cristina; Stuppia, Liborio; Seemanova, Eva; Pennacchio, Len A.; Gelb, Bruce D.; Dallapiccola, Bruno; Wittinghofer, Alfred; Ahmadian, Mohammad R.; Tartaglia, Marco; Zenker, Martin

Noonan syndrome, a developmental disorder characterized by congenital heart defects, reduced growth, facial dysmorphism and variable cognitive deficits, is caused by constitutional dysregulation of the RAS-MAPK signaling pathway. Here we report that germline NRAS mutations conferring enhanced

Autosomal recessive retinitis pigmentosa caused by mutations in the MAK gene.

Science.gov (United States)

Stone, Edwin M; Luo, Xunda; Héon, Elise; Lam, Byron L; Weleber, Richard G; Halder, Jennifer A; Affatigato, Louisa M; Goldberg, Jacqueline B; Sumaroka, Alexander; Schwartz, Sharon B; Cideciyan, Artur V; Jacobson, Samuel G

2011-12-28

To determine the disease expression in autosomal recessive (ar) retinitis pigmentosa (RP) caused by mutations in the MAK (male germ cell-associated kinase) gene. Patients with RP and MAK gene mutations (n = 24; age, 32-77 years at first visit) were studied by ocular examination, perimetry, and optical coherence tomography (OCT). All but one MAK patient were homozygous for an identical truncating mutation in exon 9 and had Ashkenazi Jewish heritage. The carrier frequency of this mutation among 1207 unrelated Ashkenazi control subjects was 1 in 55, making it the most common cause of heritable retinal disease in this population and MAK-associated RP the sixth most common Mendelian disease overall in this group. Visual acuities could be normal into the eighth decade of life. Kinetic fields showed early loss in the superior-temporal quadrant. With more advanced disease, superior and midperipheral function was lost, but the nasal field remained. Only a central island was present at late stages. Pigmentary retinopathy was less prominent in the superior nasal quadrant. Rod-mediated vision was abnormal but detectable in the residual field; all patients had rod>cone dysfunction. Photoreceptor layer thickness was normal centrally but decreased with eccentricity. At the stages studied, there was no evidence of photoreceptor ciliary elongation. The patterns of disease expression in the MAK form of arRP showed some resemblance to patterns described in autosomal dominant RP, especially the form caused by RP1 mutations. The similarity in phenotypes is of interest, considering that there is experimental evidence of interaction between Mak and RP1 in the photoreceptor cilium.

A novel heterozygous SOX2 mutation causing anophthalmia/microphthalmia with genital anomalies.

Science.gov (United States)

Pedace, Lucia; Castori, Marco; Binni, Francesco; Pingi, Alberto; Grammatico, Barbara; Scommegna, Salvatore; Majore, Silvia; Grammatico, Paola

2009-01-01

Anophthalmia/microphthalmia is a rare developmental craniofacial defect, which recognizes a wide range of causes, including chromosomal abnormalities, single-gene mutations as well as environmental factors. Heterozygous mutations in the SOX2 gene are the most common monogenic form of anophthalmia/microphthalmia, as they are reported in up to 10-15% cases. Here, we describe a sporadic patient showing bilateral anophthalmia/microphthalmia and micropenis caused by a novel mutation (c.59_60insGG) in the SOX2 gene. Morphological and endocrinological evaluations excluded any anomaly of the hypothalamus-pituitary axis. Our finding supports the hypothesis that SOX2 is particularly prone to slipped-strand mispairing, which results in a high frequency of point deletions/insertions.

An ENU-induced point mutation in the mouse Btaf1 gene causes post-gastrulation embryonic lethality and protein instability

NARCIS (Netherlands)

Wansleeben, C.; van Gurp, L.; de Graaf, P.; Mousson, F.; Timmers, H.T.; Meijlink, F.

2011-01-01

The mouse Btaf1 gene, an ortholog of yeast MOT1, encodes a highly conserved general transcription factor. The function of this SNF2-like ATPase has been studied mainly in yeast and human cells, which has revealed that it binds directly to TBP, forming the B-TFIID complex. This complex binds to core

Induced mutations for resistance to leaf rust in wheat

International Nuclear Information System (INIS)

Borojevic, K.

1983-01-01

Problems related to the induction of mutations for disease resistance were investigated under several aspects, using the wheat/leaf rust system. Previously selected mutant lines, tested in M 11 and M 13 , were found to differ with regard to infection type and disease severity from the original varieties. To verify the induced-mutation origin, these mutants were examined further using test crosses with carriers of known genes for leaf rust resistance and electrophoresis. A separate experiment to induce mutations for leaf rust resistance in the wheat varieties Sava, Aurora and Siete Cerros, using gamma rays, fast neutrons and EMS, yielded mutants with different disease reaction in the varieties Sava and Aurora at a frequency of about 1x10 - 3 per M 1 plant progenies. (author)

Splicing Analysis of Exonic OCRL Mutations Causing Lowe Syndrome or Dent-2 Disease

Directory of Open Access Journals (Sweden)

Lorena Suarez-Artiles

2018-01-01

Full Text Available Mutations in the OCRL gene are associated with both Lowe syndrome and Dent-2 disease. Patients with Lowe syndrome present congenital cataracts, mental disabilities and a renal proximal tubulopathy, whereas patients with Dent-2 disease exhibit similar proximal tubule dysfunction but only mild, or no additional clinical defects. It is not yet understood why some OCRL mutations cause the phenotype of Lowe syndrome, while others develop the milder phenotype of Dent-2 disease. Our goal was to gain new insights into the consequences of OCRL exonic mutations on pre-mRNA splicing. Using predictive bioinformatics tools, we selected thirteen missense mutations and one synonymous mutation based on their potential effects on splicing regulatory elements or splice sites. These mutations were analyzed in a minigene splicing assay. Results of the RNA analysis showed that three presumed missense mutations caused alterations in pre-mRNA splicing. Mutation c.741G>T; p.(Trp247Cys generated splicing silencer sequences and disrupted splicing enhancer motifs that resulted in skipping of exon 9, while mutations c.2581G>A; p.(Ala861Thr and c.2581G>C; p.(Ala861Pro abolished a 5′ splice site leading to skipping of exon 23. Mutation c.741G>T represents the first OCRL exonic variant outside the conserved splice site dinucleotides that results in alteration of pre-mRNA splicing. Our results highlight the importance of evaluating the effects of OCRL exonic mutations at the mRNA level.

Mutations in the pericentrin (PCNT) gene cause primordial dwarfism

NARCIS (Netherlands)

Rauch, Anita; Thiel, Christian T.; Schindler, Detlev; Wick, Ursula; Crow, Yanick J.; Ekici, Arif B.; van Essen, Anthonie J.; Goecke, Timm O.; Al-Gazali, Lihadh; Chrzanowska, Krystyna H.; Zweier, Christiane; Brunner, Han G.; Becker, Kristin; Curry, Cynthia J.; Dallapiccola, Bruno; Devriendt, Koenraad; Doerfler, Arnd; Kinning, Esther; Megarbane, Andre; Meinecke, Peter; Semple, Robert K.; Spranger, Stephanie; Toutain, Annick; Trembath, Richard C.; Voss, Egbert; Wilson, Louise; Hennekam, Raoul; de Zegher, Francis; Doerr, Helmuth-Guenther; Reis, Andre

2008-01-01

Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss- of- function mutations in the centrosomal pericentrin ( PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial

A De novo Mutation in Dystrophin Causing Muscular Dystrophy in a Female Patient

Directory of Open Access Journals (Sweden)

Hao Yu

2017-01-01

Conclusions: We identified two novel de novo mutations of DMD gene in two Chinese pedigrees, one of which caused a female patient with muscular dystrophy. The mutational analysis is important for DMD patients and carriers in the absence of a family history. The NGS can help detect the mutations in MLPA-negative patients.

A frame-shift mutation of PMS2 is a widespread cause of Lynch syndrome

DEFF Research Database (Denmark)

Clendenning, Mark; Senter, Leigha; Hampel, Heather

2008-01-01

BACKGROUND: When compared to the other mismatch repair genes involved in Lynch syndrome, the identification of mutations within PMS2 has been limited (Lynch syndrome cases...... on immunohistochemical analysis. RESULTS: We have identified a frequently occurring frame-shift mutation (c.736_741del6ins11) in 12 ostensibly unrelated Lynch syndrome patients (20% of patients we have identified with a deleterious mutation in PMS2, n=61). These individuals all display the rare allele (population...... are caused by PMS2. This disparity is primarily due to complications in the study of this gene caused by interference from pseudogene sequences. METHODS: Using a recently developed method for detecting PMS2 specific mutations, we have screened 99 patients who are likely candidates for PMS2 mutations based...

Sucrose and IQ induced mutations in rat colon by independent

DEFF Research Database (Denmark)

Hansen, Max; Hald, M. T.; Autrup, H.

2004-01-01

Sucrose-rich diets have repeatedly been observed to have co-carcinogenic actions in colon and liver of rats and to increase the number of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) induced aberrant crypt foci in rat colon. To investigate a possible interaction between sucrose and IQ...... on the genotoxicity in rat liver and colon, we gave Big Blue rats(TM) a diet containing sucrose (0%, 3.45% or 13.4% w/w) and/or IQ (70 ppm) for a period of 3 weeks. Sucrose and IQ increased the mutation frequency in the colon. The effect of combined treatments with IQ and sucrose on the mutation frequencies...... was additive indicating that sucrose and IQ act independently. This was supported by the mutation spectra where sucrose expands the background mutations in the colon, whereas IQ, in other studies, more specifically has induced G:C --> T:A transversions. In the liver IQ increased the mutation frequency, whereas...

Mutations in the pericentrin (PCNT) gene cause primordial dwarfism

NARCIS (Netherlands)

Rauch, Anita; Thiel, Christian T.; Schindler, Detlev; Wick, Ursula; Crow, Yanick J.; Ekici, Arif B.; van Essen, Anthonie J.; Goecke, Timm O.; Al-Gazali, Lihadh; Chrzanowska, Krystyna H.; Zweier, Christiane; Brunner, Han G.; Becker, Kristin; Curry, Cynthia J.; Dallapiccola, Bruno; Devriendt, Koenraad; Dörfler, Arnd; Kinning, Esther; Megarbane, André; Meinecke, Peter; Semple, Robert K.; Spranger, Stephanie; Toutain, Annick; Trembath, Richard C.; Voss, Egbert; Wilson, Louise; Hennekam, Raoul; de Zegher, Francis; Dörr, Helmuth-Günther; Reis, André

2008-01-01

Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss-of-function mutations in the centrosomal pericentrin (PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial dwarfism

Dominant KCNA2 mutation causes episodic ataxia and pharmacoresponsive epilepsy.

Science.gov (United States)

Corbett, Mark A; Bellows, Susannah T; Li, Melody; Carroll, Renée; Micallef, Silvana; Carvill, Gemma L; Myers, Candace T; Howell, Katherine B; Maljevic, Snezana; Lerche, Holger; Gazina, Elena V; Mefford, Heather C; Bahlo, Melanie; Berkovic, Samuel F; Petrou, Steven; Scheffer, Ingrid E; Gecz, Jozef

2016-11-08

To identify the genetic basis of a family segregating episodic ataxia, infantile seizures, and heterogeneous epilepsies and to study the phenotypic spectrum of KCNA2 mutations. A family with 7 affected individuals over 3 generations underwent detailed phenotyping. Whole genome sequencing was performed on a mildly affected grandmother and her grandson with epileptic encephalopathy (EE). Segregating variants were filtered and prioritized based on functional annotations. The effects of the mutation on channel function were analyzed in vitro by voltage clamp assay and in silico by molecular modeling. KCNA2 was sequenced in 35 probands with heterogeneous phenotypes. The 7 family members had episodic ataxia (5), self-limited infantile seizures (5), evolving to genetic generalized epilepsy (4), focal seizures (2), and EE (1). They had a segregating novel mutation in the shaker type voltage-gated potassium channel KCNA2 (CCDS_827.1: c.765_773del; p.255_257del). A rare missense SCN2A (rs200884216) variant was also found in 2 affected siblings and their unaffected mother. The p.255_257del mutation caused dominant negative loss of channel function. Molecular modeling predicted repositioning of critical arginine residues in the voltage-sensing domain. KCNA2 sequencing revealed 1 de novo mutation (CCDS_827.1: c.890G>A; p.Arg297Gln) in a girl with EE, ataxia, and tremor. A KCNA2 mutation caused dominantly inherited episodic ataxia, mild infantile-onset seizures, and later generalized and focal epilepsies in the setting of normal intellect. This observation expands the KCNA2 phenotypic spectrum from EE often associated with chronic ataxia, reflecting the marked variation in severity observed in many ion channel disorders. © 2016 American Academy of Neurology.

Re-analysis of radiation-induced specific locus mutations in the mouse

International Nuclear Information System (INIS)

Abrahamson, S.; Wolff, S.

1976-01-01

It is stated that a re-analysis of published data on mouse mutation rates induced by x-and gamma rays suggests that the kinetics of induction can be analysed by fitting that data to a parabolic curve. This is interpreted to mean that a substantial proportion of the induced mutations results from gross chromosomal changes such as deletions, some of which are one-track and some of which are two-track. This analysis is based on the assumption that the shape of the dose curve, which in the female is concave upward, reflects the manner in which the mutations are induced rather than representing a one-track (linear) curve whose shape has been modified by differential repair. (author)

A novel mutation of the fibrillin gene causing Ectopia lentis

Energy Technology Data Exchange (ETDEWEB)

Loennqvist, L.; Kainulainen, K.; Puhakka, L.; Peltonen, L. (National Public Health Institute, Helsinki (Finland)); Child, A. (St. George' s Hospital Medical School, London (United Kingdom)); Peltonen, L. (Duncan Guthrie Institute, Glasgow, Scotland (United Kingdom))

1994-02-01

Ectopia lentis (EL), a dominantly inherited connective tissue disorder, has been genetically linked to the fibrillin gene on chromosome 15 (FBN1) in earlier studies. Here, the authors report the first EL mutation in the FBN1 gene confirming that EL is caused by mutations of this gene. So far, several mutations in the FBN1 gene have been reported in patients with Marfan syndrome (MFS). EL and MFS are clinically related but distinct conditions with typical manifestations in the ocular and skeletal systems, the fundamental difference between them being the absence of cardiovascular involvement in EL. They report a point mutation, cosegregating with the disease in the described family, that displays EL over four generations. The mutation changes a conserved glutamic acid residue in an EGF-like motif, which is the major structural component of the fibrillin and is repeated throughout the polypeptide. In vitro mutagenetic studies have demonstrated the necessity of an analogous glutamic acid residue for calcium binding in an EGF-like repeat of human factor IX. This provides a possible explanation for the role of this mutation in the disease pathogenesis. 32 refs., 2 figs., 1 tab.

Mutations in calmodulin cause ventricular tachycardia and sudden cardiac death

DEFF Research Database (Denmark)

Nyegaard, Mette; Overgaard, Michael Toft; Sondergaard, M.T.

2012-01-01

a substantial part of sudden cardiac deaths in young individuals. Mutations in RYR2, encoding the cardiac sarcoplasmic calcium channel, have been identified as causative in approximately half of all dominantly inherited CPVT cases. Applying a genome-wide linkage analysis in a large Swedish family with a severe......Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a devastating inherited disorder characterized by episodic syncope and/or sudden cardiac arrest during exercise or acute emotion in individuals without structural cardiac abnormalities. Although rare, CPVT is suspected to cause...... calmodulin-binding-domain peptide at low calcium concentrations. We conclude that calmodulin mutations can cause severe cardiac arrhythmia and that the calmodulin genes are candidates for genetic screening of individual cases and families with idiopathic ventricular tachycardia and unexplained sudden cardiac...

Muscle imaging in patients with tubular aggregate myopathy caused by mutations in STIM1

DEFF Research Database (Denmark)

Tasca, Giorgio; D'Amico, Adele; Monforte, Mauro

2015-01-01

Tubular aggregate myopathy is a genetically heterogeneous disease characterized by tubular aggregates as the hallmark on muscle biopsy. Mutations in STIM1 have recently been identified as one genetic cause in a number of tubular aggregate myopathy cases. To characterize the pattern of muscle...... involvement in this disease, upper and lower girdles and lower limbs were imaged in five patients with mutations in STIM1, and the scans were compared with two patients with tubular aggregate myopathy not caused by mutations in STIM1. A common pattern of involvement was found in STIM1-mutated patients...... of thigh and posterior leg with sparing of gracilis, tibialis anterior and, to a lesser extent, short head of biceps femoris. Mutations in STIM1 are associated with a homogeneous involvement on imaging despite variable clinical features. Muscle imaging can be useful in identifying STIM1-mutated patients...

UVA-induced mutational spectra in the laci gene from transgenic mouse skin

International Nuclear Information System (INIS)

Gorelick, N.J.; O'Kelly, J.A.; Biedermann, K.A.

1995-01-01

The UVB (295-320 nm) component of sunlight was once thought to be the sole cause of photoaging and skin cancer. However, there is now compelling evidence to suggest that chronic irradiation with UVA (320-400 nm) is a significant component of the etiologies of these diseases. To identify acute markers of UVA damage, we investigated UVA-induced mutagenesis in vivo by using a lacI transgenic mouse mutation assay. The backs of adult female C57BL/6 Big Blue reg-sign mice were shaved and exposed daily to a low or a high dose of UVA for 5 consecutive days. One group remained unexposed. The high dose of UVA significantly increased the mutant frequency in skin determined 12 days after the last exposure. Mutant frequencies were (Avg ± SEM, n=7-8/group): 6.1 ± 0.5 x 10 -5 (high dose). DNA sequence analysis of mutant lacI genes demonstrated that the high dose of UVA produced a different mutational spectrum compared to control. The mutational spectrum from the low dose mutants was not different from the control spectrum in skin generated previously; the predominant classes of recovered mutations were GC→At transitions at CpG sites (11/35) and GC →TA transversions (12/35). In contrast, in the high dose group, GC →AT transitions at non-CpG sites predominated (61/97 mutations); three tandem base substitutions (1 GG →AA; 2 CC→TT) were uniquely recovered; and an increased frequency of recovered GC→CG substitutions was observed (12/97 vs. none in controls). The recovered high dose spectrum is consistent with the types of DNA damage generated by UVA as well as by reactive oxygen species. These studies demonstrate that UVA is mutagenic in vivo and that this assay can be used to study early events in UVA-induced skin damage

Use of induced mutations for potato improvement

International Nuclear Information System (INIS)

Kishore, H.; Das, B.; Subramanyam, K.N.; Chandra, R.; Upadhya, M.D.

1975-01-01

The investigations aim at the utilization of induced mutations for potato improvement. The effect of γ-rays was tested on selfed seeds and hybrid seeds as well as on tubers of several potato varieties. Chemical mutagens have been successfully employed to produce daylength neutral clones. An attempt to induce resistance against Pseudomonas solanacearum did not give conclusive results. Potato improvement in relation of yield and other characters of economic significance like maturity and attributes of tubers has been handicapped by several technical considerations world over. The crux of the problem lies in the narrow genetic base (variability) for potato breeders to work with. The use of mutation breeding, therefore, offers a good tool for this. Improvement by mutation breeding for the quantitative characters besides the resistance to disease and pest has been demonstrated in other crops like white mustard variety Primex (Anderson and Olsson, 1954), barley (Gustafsson, 1965) and peanut (Gregory, 1956). Keeping these in view and the success we had in isolating photoperiod insensitive types (Upadhaya et al, 1973, 1974) study was enlarged to use mutagens to increase as wide a spectrum as possible of the variability for quantative and qualitative characters. (author)

Characterization of mutations causing rifampicin and isoniazid resistance of Mycobacterium tuberculosis in Syria.

Science.gov (United States)

Madania, Ammar; Habous, Maya; Zarzour, Hana; Ghoury, Ifad; Hebbo, Barea

2012-01-01

In order to characterize mutations causing rifampicin and isoniazid resistance of M. tuberculosis in Syria, 69 rifampicin resistant (Rif(r)) and 72 isoniazid resistant (Inh(r)) isolates were screened for point mutations in hot spots of the rpoB, katG and inhA genes by DNA sequencing and real time PCR. Of 69 Rif(r) isolates, 62 (90%) had mutations in the rifampin resistance determining region (RRDR) of the rpoB gene, with codons 531 (61%), 526 (13%), and 516 (8.7%) being the most commonly mutated. We found two new mutations (Asp516Thr and Ser531Gly) described for the first time in the rpoB-RRDR in association with rifampicin resistance. Only one mutation (Ile572Phe) was found outside the rpoB-RRDR. Of 72 Inh(r) strains, 30 (41.6%) had a mutation in katGcodon315 (with Ser315Thr being the predominant alteration), and 23 (32%) harbored the inhA(-15C-->T) mutation. While the general pattern of rpoB-RRDR and katG mutations reflected those found worldwide, the prevalence of the inhA(-15C-->T mutation was above the value found in most other countries, emphasizing the great importance of testing the inhA(-15C-->T) mutation for prediction of isoniazid resistance in Syria. Sensitivity of a rapid test using real time PCR and 3'-Minor groove binder (MGB) probes in detecting Rif(r) and Inh(r) isolates was 90% and 69.4%, respectively. This demonstrates that a small set of MGB-probes can be used in real time PCR in order to detect most mutations causing resistance to rifampicin and isoniazid.

A novel NHS mutation causes Nance-Horan Syndrome in a Chinese family.

Science.gov (United States)

Tian, Qi; Li, Yunping; Kousar, Rizwana; Guo, Hui; Peng, Fenglan; Zheng, Yu; Yang, Xiaohua; Long, Zhigao; Tian, Runyi; Xia, Kun; Lin, Haiying; Pan, Qian

2017-01-07

Nance-Horan Syndrome (NHS) (OMIM: 302350) is a rare X-linked developmental disorder characterized by bilateral congenital cataracts, with occasional dental anomalies, characteristic dysmorphic features, brachymetacarpia and mental retardation. Carrier females exhibit similar manifestations that are less severe than in affected males. Here, we report a four-generation Chinese family with multiple affected individuals presenting Nance-Horan Syndrome. Whole-exome sequencing combined with RT-PCR and Sanger sequencing was used to search for a genetic cause underlying the disease phenotype. Whole-exome sequencing identified in all affected individuals of the family a novel donor splicing site mutation (NM_198270: c.1045 + 2T > A) in intron 4 of the gene NHS, which maps to chromosome Xp22.13. The identified mutation results in an RNA processing defect causing a 416-nucleotide addition to exon 4 of the mRNA transcript, likely producing a truncated NHS protein. The donor splicing site mutation NM_198270: c.1045 + 2T > A of the NHS gene is the causative mutation in this Nance-Horan Syndrome family. This research broadens the spectrum of NHS gene mutations, contributing to our understanding of the molecular genetics of NHS.

Recessive mutations in ELOVL4 cause ichthyosis, intellectual disability, and spastic quadriplegia.

Science.gov (United States)

Aldahmesh, Mohammed A; Mohamed, Jawahir Y; Alkuraya, Hisham S; Verma, Ishwar C; Puri, Ratna D; Alaiya, Ayodele A; Rizzo, William B; Alkuraya, Fowzan S

2011-12-09

Very-long-chain fatty acids (VLCFAs) play important roles in membrane structure and cellular signaling, and their contribution to human health is increasingly recognized. Fatty acid elongases catalyze the first and rate-limiting step in VLCFA synthesis. Heterozygous mutations in ELOVL4, the gene encoding one of the elongases, are known to cause macular degeneration in humans and retinal abnormalities in mice. However, biallelic ELOVL4 mutations have not been observed in humans, and murine models with homozygous mutations die within hours of birth as a result of a defective epidermal water barrier. Here, we report on two human individuals with recessive ELOVL4 mutations revealed by a combination of autozygome analysis and exome sequencing. These individuals exhibit clinical features of ichthyosis, seizures, mental retardation, and spasticity-a constellation that resembles Sjögren-Larsson syndrome (SLS) but presents a more severe neurologic phenotype. Our findings identify recessive mutations in ELOVL4 as the cause of a neuro-ichthyotic disease and emphasize the importance of VLCFA synthesis in brain and cutaneous development. Copyright © 2011 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Some results on the combined use of induced mutations and heterosis breeding

International Nuclear Information System (INIS)

Stoilov, M.; Daskaloff, S.

1976-01-01

The literature on the combined use of induced mutations and heterosis in cultivated species is reviewed. Data from studies of the general and specific combining ability of induced mutations for gene markers both obtained and used in hybrid seed production, translocation lines for development of seedless fruits, male sterile forms, etc., are supplied. The authors give data from their own experimental material for use of mutant lines in heterosis breeding and hybrid seed production. It is concluded that the combined use of induced mutations and heterosis in both self- and cross-pollinating species is very promising. (author)

Frontotemporal dementia caused by CHMP2B mutation is characterised by neuronal lysosomal storage pathology

DEFF Research Database (Denmark)

Clayton, Emma L.; Mizielinska, Sarah; Edgar, James R.

2015-01-01

Mutations in the charged multivesicular body protein 2B (CHMP2B) cause frontotemporal dementia (FTD). We report that mice which express FTD-causative mutant CHMP2B at physiological levels develop a novel lysosomal storage pathology characterised by large neuronal autofluorescent aggregates...... in human CHMP2B mutation brain than in neurodegenerative disease or age-matched control brains. These data suggest that lysosomal storage pathology is the major neuronal pathology in FTD caused by CHMP2B mutation. Recent evidence suggests that two other genes associated with FTD, GRN and TMEM106B...... are important for lysosomal function. Our identification of lysosomal storage pathology in FTD caused by CHMP2B mutation now provides evidence that endolysosomal dysfunction is a major degenerative pathway in FTD....

Improving protein quality of soybean through induced mutations

International Nuclear Information System (INIS)

Manjaya, J.G.

2011-01-01

Soybean is one of the most economical and nutritious food packed with basic nutrients that combat diseases stemming from mal- and under-nutrition. Despite its rich nutritional profile, use of soybean in food has been limited because soybean proteins are often associated with compounds, which could exert a negative impact on the nutritional quality of the protein. Trypsin inhibitor (TI) is one of the important anti-nutritional factors that exert negative effect by causing growth inhibition. Soybean cultivar VLS-2 was irradiated with 250 Gy gamma rays in a gamma cell (200) with 60 Co source installed at BARC to induce mutations for low trypsin inhibitor content. Three mutants with lower levels of TI content were identified and can be utilized for developing elite varieties of soybean. (author)

Retigabine, a Kv7.2/Kv7.3-Channel Opener, Attenuates Drug-Induced Seizures in Knock-In Mice Harboring Kcnq2 Mutations.

Science.gov (United States)

Ihara, Yukiko; Tomonoh, Yuko; Deshimaru, Masanobu; Zhang, Bo; Uchida, Taku; Ishii, Atsushi; Hirose, Shinichi

2016-01-01

The hetero-tetrameric voltage-gated potassium channel Kv7.2/Kv7.3, which is encoded by KCNQ2 and KCNQ3, plays an important role in limiting network excitability in the neonatal brain. Kv7.2/Kv7.3 dysfunction resulting from KCNQ2 mutations predominantly causes self-limited or benign epilepsy in neonates, but also causes early onset epileptic encephalopathy. Retigabine (RTG), a Kv7.2/ Kv7.3-channel opener, seems to be a rational antiepileptic drug for epilepsies caused by KCNQ2 mutations. We therefore evaluated the effects of RTG on seizures in two strains of knock-in mice harboring different Kcnq2 mutations, in comparison to the effects of phenobarbital (PB), which is the first-line antiepileptic drug for seizures in neonates. The subjects were heterozygous knock-in mice (Kcnq2Y284C/+ and Kcnq2A306T/+) bearing the Y284C or A306T Kcnq2 mutation, respectively, and their wild-type (WT) littermates, at 63-100 days of age. Seizures induced by intraperitoneal injection of kainic acid (KA, 12mg/kg) were recorded using a video-electroencephalography (EEG) monitoring system. Effects of RTG on KA-induced seizures of both strains of knock-in mice were assessed using seizure scores from a modified Racine's scale and compared with those of PB. The number and total duration of spike bursts on EEG and behaviors monitored by video recording were also used to evaluate the effects of RTG and PB. Both Kcnq2Y284C/+ and Kcnq2A306T/+ mice showed significantly more KA-induced seizures than WT mice. RTG significantly attenuated KA-induced seizure activities in both Kcnq2Y284C/+ and Kcnq2A306T/+ mice, and more markedly than PB. This is the first reported evidence of RTG ameliorating KA-induced seizures in knock-in mice bearing mutations of Kcnq2, with more marked effects than those observed with PB. RTG or other Kv7.2-channel openers may be considered as first-line antiepileptic treatments for epilepsies resulting from KCNQ2 mutations.

A sodium-channel mutation causes isolated cardiac conduction disease

NARCIS (Netherlands)

Tan, H. L.; Bink-Boelkens, M. T.; Bezzina, C. R.; Viswanathan, P. C.; Beaufort-Krol, G. C.; van Tintelen, P. J.; van den Berg, M. P.; Wilde, A. A.; Balser, J. R.

2001-01-01

Cardiac conduction disorders slow the heart rhythm and cause disability in millions of people worldwide. Inherited mutations in SCN5A, the gene encoding the human cardiac sodium (Na+) channel, have been associated with rapid heart rhythms that occur suddenly and are life-threatening; however, a

Development of breeding materials in rice by use of induced mutation

International Nuclear Information System (INIS)

Amano, Etsuo

1988-01-01

On this 25th Gamma Field Symposium, it may be worth while to review the world situation of mutation breeding, the possibility expected to mutation methods suggested by the ever progressing genetics in rice plant, and some of the activities in the Institute of Radiation Breeding. By the help of a small computer, the key word search analysis of 'Mutation Breeding Newsletter and Mutation Breeding Review' was tried, and the results are included in this review to see the present status. The studies on artificially induced mutation suggested that the possibility of dominant mutation is less. It might be probable that the inactivation of genes is the mechanism of mutation. Still the possibility of using mutation breeding techniques for many genetic characters was suggested. After the experience for 25 years, detailed genetical and fine structure analyses became important. The studies on the expression of mutant phenotypes including molecular genetics will help to develop radiation breeding into an effective means to enrich the genetic resources for breeding. The situation in the world, the genes reported in rice, the possibility to induce useful mutants against environmental stress, the mutation in the protein content in grains, the mutants of storage carbohydrate, the possibility to widen gene resources and so on are reported. (Kako, I.)

Radiation-induced cell mutations as a function of dose rate

International Nuclear Information System (INIS)

Kiefer, J.

1987-01-01

A brief review of the data in the literature is presented and forms the background of the experimental data given by the author obtained with exponential long-term cultures of V79 hamster cells exposed over a period of up to 35 days to different dose rates of gamma radiation. The experimental results show that at a dose rate of 40 mGy/hour the number of induced mutations is reduced, - which is in agreement with literature data - , but a dose rate of less than 30 mGy/hour makes the induced mutations leap to a value clearly higher than those induced by acute irradiation. As in addition to the mutations recombination is a significant factor of the radiation risk, experiments with a heterozygotic yeast strain have been made, as there is to date no reliable mammalian cell system available for this kind of research. Long-term radiation exposure of the yeast cells over a period of six weeks drastically increased the rate of recombinations, to a value higher by a factor of about 4 than that induced by acute irradiation. (orig.) [de

Translesion DNA synthesis and mutation induced in a plasmid with a single adduct of the environmental contaminant 3-nitrobenzanthrone in SOS-induced Escherichia coli

International Nuclear Information System (INIS)

Kawanishi, M.; Kanno, T.; Yagi, T.; Enya-Takamura, T.; Fuchs, R.P.

2003-01-01

Full text: 3-Nitrobenzanthrone (NBA) is a powerfully mutagenic nitrated aromatic hydrocarbon found in diesel exhaust and in airborne particulate matters. NBA forms an unusual DNA adduct in vitro that has a C-C bond between the C-8 position of deoxyguanosine and the C-2 position of NBA. We previously found that this adduct is also present in the human cells treated with NBA, and induces mutations in supF shuttle vector system. In this study, we analyzed translesion DNA synthesis (TLS) over a single adduct in lacZ' gene in a plasmid in uvrAmutS Escherichia coli. The result showed that the adduct blocked DNA replication and an observed TLS frequency was 5.4% in non-SOS-induced E. coli. All progenies after the TLS had no mutation. On the other hand, TLS increased to 11.3%, and 4.8% of them had mostly G to T mutations in SOS-induced E. coli. These results suggest that this unusual adduct would be one of causes of lung cancer that is increasing in the urban areas polluted with diesel exhaust. It must be interesting to reveal which DNA polymerase is involved in this TLS

De novo mutations in ATP1A3 cause alternating hemiplegia of childhood

DEFF Research Database (Denmark)

Heinzen, Erin L; Swoboda, Kathryn J; Hitomi, Yuki

2012-01-01

and their unaffected parents to identify de novo nonsynonymous mutations in ATP1A3 in all seven individuals. In a subsequent sequence analysis of ATP1A3 in 98 other patients with AHC, we found that ATP1A3 mutations were likely to be responsible for at least 74% of the cases; we also identified one inherited mutation...... affecting the level of protein expression. This work identifies de novo ATP1A3 mutations as the primary cause of AHC and offers insight into disease pathophysiology by expanding the spectrum of phenotypes associated with mutations in ATP1A3....

Use of induced mutations for cotton breeding in India

International Nuclear Information System (INIS)

Raut, R.N.

1980-01-01

A large number of studies have been reported in recent years on the use of induced mutations in the improvement of food crops and ornamentals. Similar investigations on fibre crops like cotton have, however, been relatively few. The fact that most of the economically useful characters in cotton are under polygenic control appears to be the main limiting factor. Inspite of this there are reports of radiation induced useful mutations used as commercial varieties. As early as 1950 a X-ray induced mutant variety of G. hirsutum cotton Indore-2 was released for commercial cultivation in Madhya Pradesh and covered more than one lac hectares. More recently an early maturing mutant variety MCU-7 was released for cultivation in summer rice fallows of Tamil Nadu and covers nearly 10,000 acres. Other promising mutant strains found suitable b.v large scale trials and recommended for cultivation under specific conditions are Okra leaf mutant, photoinsensitive mutant of MCU-5 (named Rasmi) and Jassid tolerant early maturing mutant 4-1 (Pusa Ageti). In addition improved varieties like Badnaawar-1, Khandwa-2 and M64 have been evolved by utilizing mutant lines in cross breeding. The scope of induced mutation method as a breeding technique for cotton improvement in India is very wide. (author)

A sodium-channel mutation causes isolated cardiac conduction disease

NARCIS (Netherlands)

Tan, HL; Bink-Boelkens, MTE; Bezzina, CR; Viswanathan, PC; Beaufort-Krol, GCM; van Tintelen, PJ; van den Berg, MP; Wilde, AAM; Balser, [No Value

2001-01-01

Cardiac conduction disorders slow the heart rhythm and cause disability in millions of people worldwide. Inherited mutations in SCN5A, the gene encoding the human cardiac sodium (Na+) channel, have been associated with rapid heart rhythms that occur suddenly and are life-threatening(1-3); however, a

SPATACSIN mutations cause autosomal recessive juvenile amyotrophic lateral sclerosis.

Science.gov (United States)

Orlacchio, Antonio; Babalini, Carla; Borreca, Antonella; Patrono, Clarice; Massa, Roberto; Basaran, Sarenur; Munhoz, Renato P; Rogaeva, Ekaterina A; St George-Hyslop, Peter H; Bernardi, Giorgio; Kawarai, Toshitaka

2010-02-01

The mutation of the spatacsin gene is the single most common cause of autosomal recessive hereditary spastic paraplegia with thin corpus callosum. Common clinical, pathological and genetic features between amyotrophic lateral sclerosis and hereditary spastic paraplegia motivated us to investigate 25 families with autosomal recessive juvenile amyotrophic lateral sclerosis and long-term survival for mutations in the spatascin gene. The inclusion criterion was a diagnosis of clinically definite amyotrophic lateral sclerosis according to the revised El Escorial criteria. The exclusion criterion was a diagnosis of hereditary spastic paraplegia with thin corpus callosum in line with an established protocol. Additional pathological and genetic evaluations were also performed. Surprisingly, 12 sequence alterations in the spatacsin gene (one of which is novel, IVS30 + 1 G > A) were identified in 10 unrelated pedigrees with autosomal recessive juvenile amyotrophic lateral sclerosis and long-term survival. The countries of origin of these families were Italy, Brazil, Canada, Japan and Turkey. The variants seemed to be pathogenic since they co-segregated with the disease in all pedigrees, were absent in controls and were associated with amyotrophic lateral sclerosis neuropathology in one member of one of these families for whom central nervous system tissue was available. Our study indicates that mutations in the spatascin gene could cause a much wider spectrum of clinical features than previously recognized, including autosomal recessive juvenile amyotrophic lateral sclerosis.

ENPP1 Mutation Causes Recessive Cole Disease by Altering Melanogenesis.

Science.gov (United States)

Chourabi, Marwa; Liew, Mei Shan; Lim, Shawn; H'mida-Ben Brahim, Dorra; Boussofara, Lobna; Dai, Liang; Wong, Pui Mun; Foo, Jia Nee; Sriha, Badreddine; Robinson, Kim Samirah; Denil, Simon; Common, John Ea; Mamaï, Ons; Ben Khalifa, Youcef; Bollen, Mathieu; Liu, Jianjun; Denguezli, Mohamed; Bonnard, Carine; Saad, Ali; Reversade, Bruno

2018-02-01

Cole disease is a genodermatosis of pigmentation following a strict dominant mode of inheritance. In this study, we investigated eight patients affected with an overlapping genodermatosis after recessive inheritance. The patients presented with hypo- and hyperpigmented macules over the body, resembling dyschromatosis universalis hereditaria in addition to punctuate palmoplantar keratosis. By homozygosity mapping and whole-exome sequencing, a biallelic p.Cys120Arg mutation in ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) was identified in all patients. We found that this mutation, like those causing dominant Cole disease, impairs homodimerization of the ENPP1 enzyme that is mediated by its two somatomedin-B-like domains. Histological analysis revealed structural and molecular changes in affected skin that were likely to originate from defective melanocytes because keratinocytes do not express ENPP1. Consistently, RNA-sequencing analysis of patient-derived primary melanocytes revealed alterations in melanocyte development and in pigmentation signaling pathways. We therefore conclude that germline ENPP1 cysteine-specific mutations, primarily affecting the melanocyte lineage, cause a clinical spectrum of dyschromatosis, in which the p.Cys120Arg allele represents a recessive and more severe form of Cole disease. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Correlation of oxidative stress in patients with HBV-induced liver disease with HBV genotypes and drug resistance mutations.

Science.gov (United States)

Xianyu, Jianbo; Feng, Jiafu; Yang, Yuwei; Tang, Jie; Xie, Gang; Fan, Lingying

2018-05-01

This study aims to explore the correlation of oxidative stress (OxS) in patients with chronic hepatitis B (CHB) and the disease severity with HBV genotypes and drug resistance mutations. A total of 296 patients with CHB were enrolled into the study. PCR-reverse dot-blot hybridization was used to detect the HBV genotypes (B, C, and D) and the drug resistance-causing HBV mutant genes. In addition, the total oxidative stress (TOS) and total antioxidant status (TAS) were determined, and oxidative stress index (OSI) was calculated and compared. Serum levels of TOS and OSI, the B/C ratio, and drug resistance mutation rate were increased along with the elevated disease severity degree (CHBHBV mutation had higher serum TOS and OSI levels, while lower serum TAS levels (P HBV-induced liver disease, and the damage degree is correlated with the HBV genotype and drug resistance mutation. Oxidative stress might be a useful indicator of the progression of HBV-induced liver disease in patients. Copyright © 2018. Published by Elsevier Inc.

Genetic improvement of 'NPq' rice with induced mutations

International Nuclear Information System (INIS)

Ram, Mahabal

1974-01-01

Exposure of the seeds of rice to different doses of gamma-rays increased the total mutation frequency with an increase in the dose rate, and the most economic mutations occurred around 30 kr. Induced mutants with dwarf plant type, early maturity, fine grain, high-yielding ability, and resistance to lodging and major diseases were isolated in the M, and M generations. Genetical studies indicated that height is controlled by 4 pairs of additive genes, grass-clumps by 2 pairs of non-allelic interacting genes (inhibitory), and chlorophyll mutations such as albina by 2 pairs of duplicate genes and xantha by a single gene pair. (author)

The heartstrings mutation in zebrafish causes heart/fin Tbx5 deficiency syndrome.

Science.gov (United States)

Garrity, Deborah M; Childs, Sarah; Fishman, Mark C

2002-10-01

Holt-Oram syndrome is one of the autosomal dominant human "heart-hand" disorders, with a combination of upper limb malformations and cardiac defects. Holt-Oram syndrome is caused by mutations in the TBX5 gene, a member of a large family of T-box transcription factors that play important roles in cell-type specification and morphogenesis. In a screen for mutations affecting zebrafish cardiac function, we isolated the recessive lethal mutant heartstrings, which lacks pectoral fins and exhibits severe cardiac dysfunction, beginning with a slow heart rate and progressing to a stretched, non-functional heart. We mapped and cloned the heartstrings mutation and find it to encode the zebrafish ortholog of the TBX5 gene. The heartstrings mutation causes premature termination at amino acid 316. Homozygous mutant embryos never develop pectoral fin buds and do not express several markers of early fin differentiation. The total absence of any fin bud differentiation distinguishes heartstrings from most other mutations that affect zebrafish fin development, suggesting that Tbx5 functions very early in the pectoral fin induction pathway. Moderate reduction of Tbx5 by morpholino causes fin malformations, revealing an additional early requirement for Tbx5 in coordinating the axes of fin outgrowth. The heart of heartstrings mutant embryos appears to form and function normally through the early heart tube stage, manifesting only a slight bradycardia compared with wild-type siblings. However, the heart fails to loop and then progressively deteriorates, a process affecting the ventricle as well as the atrium. Relative to mammals, fish require lower levels of Tbx5 to produce malformed appendages and display whole-heart rather than atrial-predominant cardiac defects. However, the syndromic deficiencies of tbx5 mutation are remarkably well retained between fish and mammals.

A novel mutation in MED12 causes FG syndrome (Opitz-Kaveggia syndrome)

NARCIS (Netherlands)

Rump, P.; Niessen, R. C.; Verbruggen, K. T.; Brouwer, O. F.; de Raad, M.; Hordijk, R.

Opitz-Kaveggia syndrome is a rare X-linked multiple congenital anomalies and intellectual disability disorder caused by the recurrent p.R961W mutation in the MED12 gene. Twenty-three affected males from 10 families with this mutation in the MED12 gene have been described so far. Here we report on a

Disease-Causing Mutations in the G Protein Gαs Subvert the Roles of GDP and GTP.

Science.gov (United States)

Hu, Qi; Shokat, Kevan M

2018-05-17

The single most frequent cancer-causing mutation across all heterotrimeric G proteins is R201C in Gαs. The current model explaining the gain-of-function activity of the R201 mutations is through the loss of GTPase activity and resulting inability to switch off to the GDP state. Here, we find that the R201C mutation can bypass the need for GTP binding by directly activating GDP-bound Gαs through stabilization of an intramolecular hydrogen bond network. Having found that a gain-of-function mutation can convert GDP into an activator, we postulated that a reciprocal mutation might disrupt the normal role of GTP. Indeed, we found R228C, a loss-of-function mutation in Gαs that causes pseudohypoparathyroidism type 1a (PHP-Ia), compromised the adenylyl cyclase-activating activity of Gαs bound to a non-hydrolyzable GTP analog. These findings show that disease-causing mutations in Gαs can subvert the canonical roles of GDP and GTP, providing new insights into the regulation mechanism of G proteins. Copyright © 2018 Elsevier Inc. All rights reserved.

Molecular analysis of formaldehyde-induced mutations in human lymphoblasts and E. coli

International Nuclear Information System (INIS)

Crosby, R.M.; Richardson, K.K.; Craft, T.R.; Benforado, K.B.; Liber, H.L.; Skopek, T.R.

1988-01-01

The molecular nature of formaldehyde (HCHO)-induced mutations was studied in both human lymphoblasts and E. coli. Thirty HPRT - human lymphoblast colonies induced by eight repetitive 150 μM HCHO treatments were characterized by Southern blot analysis. Fourteen of these mutants (47%) had visible deletions of some or all of the X-linked HPRT bands, indicating that HCHO can induce large losses of DNA in human lymphoblasts. In E. coli., DNA alterations induced by HCHO were characterized with use of the xanthine guanine phosphoribosyl transferase (gpt) gene as the genetic target. Exposure of E. coli to 4 mM HCHO for 1 hr induced large insertions (41%), large deletions (18%), and point mutations (41%). Dideoxy DNA sequencing revealed that most of the point mutations were transversions at GC base pairs. In contrast, exposure of E. coli to 40 mM HCHO for 1 hr produced 92% point mutations, 62% of which were transitions at a single AT base pair in the gene. Therefore, HCHO is capable of producing different genetic alterations in E. coli at different concentrations, suggesting fundamental differences in the mutagenic mechanisms operating at the two concentrations used. Naked pSV2gpt plasmid DNA was exposed to 3.3 or 10 mM HCHO and transformed into E. coli. Most of the resulting mutations were frameshifts, again suggesting a different mutagenic mechanism

Novel autosomal dominant TNNT1 mutation causing nemaline myopathy.

Science.gov (United States)

Konersman, Chamindra G; Freyermuth, Fernande; Winder, Thomas L; Lawlor, Michael W; Lagier-Tourenne, Clotilde; Patel, Shailendra B

2017-11-01

Nemaline myopathy (NEM) is one of the three major forms of congenital myopathy and is characterized by diffuse muscle weakness, hypotonia, respiratory insufficiency, and the presence of nemaline rod structures on muscle biopsy. Mutations in troponin T1 (TNNT1) is 1 of 10 genes known to cause NEM. To date, only homozygous nonsense mutations or compound heterozygous truncating or internal deletion mutations in TNNT1 gene have been identified in NEM. This extended family is of historical importance as some members were reported in the 1960s as initial evidence that NEM is a hereditary disorder. Proband and extended family underwent Sanger sequencing for TNNT1. We performed RT-PCR and immunoblot on muscle to assess TNNT1 RNA expression and protein levels in proband and father. We report a novel heterozygous missense mutation of TNNT1 c.311A>T (p.E104V) that segregated in an autosomal dominant fashion in a large family residing in the United States. Extensive sequencing of the other known genes for NEM failed to identify any other mutant alleles. Muscle biopsies revealed a characteristic pattern of nemaline rods and severe myofiber hypotrophy that was almost entirely restricted to the type 1 fiber population. This novel mutation alters a residue that is highly conserved among vertebrates. This report highlights not only a family with autosomal dominant inheritance of NEM, but that this novel mutation likely acts via a dominant negative mechanism. © 2017 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.

BRF1 mutations alter RNA polymerase III–dependent transcription and cause neurodevelopmental anomalies

Science.gov (United States)

Hög, Friederike; Dentici, Maria Lisa; Tan, Perciliz L.; Sowada, Nadine; Medeira, Ana; Gueneau, Lucie; Thiele, Holger; Kousi, Maria; Lepri, Francesca; Wenzeck, Larissa; Blumenthal, Ian; Radicioni, Antonio; Schwarzenberg, Tito Livio; Mandriani, Barbara; Fischetto, Rita; Morris-Rosendahl, Deborah J.; Altmüller, Janine; Reymond, Alexandre; Nürnberg, Peter; Merla, Giuseppe; Dallapiccola, Bruno; Katsanis, Nicholas; Cramer, Patrick; Kubisch, Christian

2015-01-01

RNA polymerase III (Pol III) synthesizes tRNAs and other small noncoding RNAs to regulate protein synthesis. Dysregulation of Pol III transcription has been linked to cancer, and germline mutations in genes encoding Pol III subunits or tRNA processing factors cause neurogenetic disorders in humans, such as hypomyelinating leukodystrophies and pontocerebellar hypoplasia. Here we describe an autosomal recessive disorder characterized by cerebellar hypoplasia and intellectual disability, as well as facial dysmorphic features, short stature, microcephaly, and dental anomalies. Whole-exome sequencing revealed biallelic missense alterations of BRF1 in three families. In support of the pathogenic potential of the discovered alleles, suppression or CRISPR-mediated deletion of brf1 in zebrafish embryos recapitulated key neurodevelopmental phenotypes; in vivo complementation showed all four candidate mutations to be pathogenic in an apparent isoform-specific context. BRF1 associates with BDP1 and TBP to form the transcription factor IIIB (TFIIIB), which recruits Pol III to target genes. We show that disease-causing mutations reduce Brf1 occupancy at tRNA target genes in Saccharomyces cerevisiae and impair cell growth. Moreover, BRF1 mutations reduce Pol III–related transcription activity in vitro. Taken together, our data show that BRF1 mutations that reduce protein activity cause neurodevelopmental anomalies, suggesting that BRF1-mediated Pol III transcription is required for normal cerebellar and cognitive development. PMID:25561519

De novo mutations in HCN1 cause early infantile epileptic encephalopathy.

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Nava, Caroline; Dalle, Carine; Rastetter, Agnès; Striano, Pasquale; de Kovel, Carolien G F; Nabbout, Rima; Cancès, Claude; Ville, Dorothée; Brilstra, Eva H; Gobbi, Giuseppe; Raffo, Emmanuel; Bouteiller, Delphine; Marie, Yannick; Trouillard, Oriane; Robbiano, Angela; Keren, Boris; Agher, Dahbia; Roze, Emmanuel; Lesage, Suzanne; Nicolas, Aude; Brice, Alexis; Baulac, Michel; Vogt, Cornelia; El Hajj, Nady; Schneider, Eberhard; Suls, Arvid; Weckhuysen, Sarah; Gormley, Padhraig; Lehesjoki, Anna-Elina; De Jonghe, Peter; Helbig, Ingo; Baulac, Stéphanie; Zara, Federico; Koeleman, Bobby P C; Haaf, Thomas; LeGuern, Eric; Depienne, Christel

2014-06-01

Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels contribute to cationic Ih current in neurons and regulate the excitability of neuronal networks. Studies in rat models have shown that the Hcn1 gene has a key role in epilepsy, but clinical evidence implicating HCN1 mutations in human epilepsy is lacking. We carried out exome sequencing for parent-offspring trios with fever-sensitive, intractable epileptic encephalopathy, leading to the discovery of two de novo missense HCN1 mutations. Screening of follow-up cohorts comprising 157 cases in total identified 4 additional amino acid substitutions. Patch-clamp recordings of Ih currents in cells expressing wild-type or mutant human HCN1 channels showed that the mutations had striking but divergent effects on homomeric channels. Individuals with mutations had clinical features resembling those of Dravet syndrome with progression toward atypical absences, intellectual disability and autistic traits. These findings provide clear evidence that de novo HCN1 point mutations cause a recognizable early-onset epileptic encephalopathy in humans.

Primary ciliary dyskinesia-causing mutations in Amish and Mennonite communities.

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Ferkol, Thomas W; Puffenberger, Erik G; Lie, Hauw; Helms, Cynthia; Strauss, Kevin A; Bowcock, Anne; Carson, John L; Hazucha, Milan; Morton, D Holmes; Patel, Anand C; Leigh, Margaret W; Knowles, Michael R; Zariwala, Maimoona A

2013-08-01

To determine whether individuals with primary ciliary dyskinesia (PCD) from unrelated Amish and Mennonite families harbor a single and unique founder mutation. Subjects from Amish and Mennonite communities in several states were enrolled in the study. All subjects were clinically characterized, and nasal nitric oxide levels were measured. Nasal epithelial scrapings were collected from several subjects for ciliary ultrastructural analyses. DNA was isolated from patients with PCD and their unaffected first- and second-degree relatives. Genome-wide homozygosity mapping, linkage analyses, targeted mutation analyses, and exome sequencing were performed. All subjects from Old-Order Amish communities from Pennsylvania were homozygous for a nonsense mutant DNAH5 allele, c.4348C>T (p.Q1450X). Two affected siblings from an unrelated Mennonite family in Arkansas were homozygous for the same nonsense DNAH5 mutation. Children with PCD from an Amish family from Wisconsin had biallelic DNAH5 mutations, c.4348C>T (p.Q1450X) and c.10815delT (p.P3606HfsX23), and mutations in other genes associated with PCD were also identified in this community. The Amish and Mennonite subjects from geographically dispersed and socially isolated communities had the same founder DNAH5 mutation, owing to the common heritage of these populations. However, disease-causing mutations in other PCD-associated genes were also found in affected individuals in these communities, illustrating the genetic heterogeneity in this consanguineous population. Copyright © 2013 Mosby, Inc. All rights reserved.

Irradiation-induced mutation experiments with eiploid and tetraploid tomato plants

International Nuclear Information System (INIS)

Boda, J.

1979-01-01

Tomato mutation experiments are described. The tomatoes used in the experiment were the diploid Reziszta and its autotetraploid variety. The experimental plants were exposed to an irradiation of 5000 rsd for 1-2 days, and after transplantation into the gamma field, to chronic irradiation during the whole growing season. The chronic treatment heavily reduced fertility in the generations of tetraploid tomato plants. Recurrent treatment of tetraploid led to further deterioration in fertility. Several berries were formed with few seeds or with no seeds at all. After three irradiations, the chlorophyll mutation frequency increased in the diploid and tetraploid tomato plants. For diploids, treatment applied at the seedling stage gave a lower chlorophyll mutation frequency. With tetraploids the same treatment induced similar chlorophyll mutation frequency. As regards to phenotypic variability of quantitative characteristics in diploid and tetraploid tomatoes, the single and repeated chronic irradiation induced no increase in the variability of properties like flowering time, weight, height etc. (author)

Genetic improvement of Sesamun indicum through induced mutations

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Rajput, M.A.; Khan, Z.H.; Jafri, K.A.; Fazal Ali, J.A.

2001-01-01

Pakistan is chronically deficient in the production of edible oils. To enhance local production of edible oils, a mutation breeding project entitled ''Genetic improvement of Sesamum indicum through induced mutations'' was initiated for developing high yielding and widely adapted varieties of sesame. Quite a few mutants having earliness, short stature, semi-indehiscence, compact plant type, heavy bearing and high seed yield have been developed. The true breeding mutant lines developed have exhibited impressive yield potential. (author)

Epilepsy caused by CDKL5 mutations.

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Castrén, Maija; Gaily, Eija; Tengström, Carola; Lähdetie, Jaana; Archer, Hayley; Ala-Mello, Sirpa

2011-01-01

Mutations in the cyclin-dependent kinase-like 5 gene (CDKL5) have been identified in female patients with early onset epileptic encephalopathy and severe mental retardation with a Rett-like phenotype. Subsequently CDKL5 mutations were shown to be associated with more diverse phenotypes including mild epilepsy and autism without epilepsy. Furthermore, CDKL5 mutations were found in patients with Angelman-like phenotype. The severity of epilepsy associated with CDKL5 mutations was recently shown to correlate with the type of CDKL5 mutations and epilepsy was identified to involve three distinct sequential stages. Here, we describe the phenotype of a severe form of neurodevelopmental disease in a female patient with a de novo nonsense mutation of the CDKL5 gene c.175C > T (p.R59X) affecting the catalytic domain of CDKL5 protein. Mutations in the CDKL5 gene are less common in males and can be associated with a genomic deletion as found in our male patient with a deletion of 0.3 Mb at Xp22.13 including the CDKL5 gene. We review phenotypes associated with CDKL5 mutations and examine putative relationships between the clinical epilepsy phenotype and the type of the mutation in the CDKL5 gene. © 2010 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Three common GJB2 mutations causing nonsyndromic hearing loss in Chinese populations are retained in the endoplasmic reticulum.

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Zhang, Yanping; Wang, Ju; Li, Lina; Sun, Yurui; Feng, Bo

2010-07-01

The three most common GJB2 mutations found in the Chinese populations, c.235delC, c.299-300delAT, and c.176-191de1 (16) bp, cannot form gap junctons (GJs) in the plasma membrane. These mutant proteins were retained in the endoplasmic reticulum (ER), suggesting that ER stress (ERS) and subsequent ERS-induced cell death may be responsible for hearing loss caused by these GJB2 truncation mutations. The objective of this study was to investigate the subcellular location of the protein products of three GJB2 mutants (c.235de1C, c.299-300delAT, and c.176-191de1 (16) bp) and to explore the deafness mechanism caused by these GJB2 truncation mutations. Mutant-eGFP fusion protein vectors were constructed by PCR and TA cloning. HEK293 cells were transfected by a liposome-mediated method. Transfected cells were incubated with ER-Tracker and observed under a confocal microscope. Cells transfected with wild type gave characteristic punctuate patterns of GJs in the cell membrane. In contrast, c.235de1C, c.299-300delAT, and c.176-191de1 (16) bp mutant proteins were found to be trapped in the ER, and were therefore unable to form GJs in the plasma membrane.

EDNRB mutations cause Waardenburg syndrome type II in the heterozygous state.

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Issa, Sarah; Bondurand, Nadege; Faubert, Emmanuelle; Poisson, Sylvain; Lecerf, Laure; Nitschke, Patrick; Deggouj, Naima; Loundon, Natalie; Jonard, Laurence; David, Albert; Sznajer, Yves; Blanchet, Patricia; Marlin, Sandrine; Pingault, Veronique

2017-05-01

Waardenburg syndrome (WS) is a genetic disorder characterized by sensorineural hearing loss and pigmentation anomalies. The clinical definition of four WS types is based on additional features due to defects in structures mostly arising from the neural crest, with type I and type II being the most frequent. While type I is tightly associated to PAX3 mutations, WS type II (WS2) remains partly enigmatic with mutations in known genes (MITF, SOX10) accounting for only 30% of the cases. We performed exome sequencing in a WS2 index case and identified a heterozygous missense variation in EDNRB. Interestingly, homozygous (and very rare heterozygous) EDNRB mutations are already described in type IV WS (i.e., in association with Hirschsprung disease [HD]) and heterozygous mutations in isolated HD. Screening of a WS2 cohort led to the identification of an overall of six heterozygous EDNRB variations. Clinical phenotypes, pedigrees and molecular segregation investigations unraveled a dominant mode of inheritance with incomplete penetrance. In parallel, cellular and functional studies showed that each of the mutations impairs the subcellular localization of the receptor or induces a defective downstream signaling pathway. Based on our results, we now estimate EDNRB mutations to be responsible for 5%-6% of WS2. © 2017 Wiley Periodicals, Inc.

p53 gene mutation hotspots in skin cancer and ultraviolet induced mutation

International Nuclear Information System (INIS)

Ikehata, Hironobu

1998-01-01

Presence of certain hotspots is known in the mutation of p53 gene in skin cancer, which are codons 177, 196, 245, 248, 278 and 282 located in the exon 5-8. In these regions, mutations like C to T and CC to TT are frequent and thereby suggest that they are resulted from pyrimidine-dimers produced by ultraviolet light (UV). In cyclobutane pyrimidine dimerization (CPD), conversion of cytosine to thymine by deamination is suggested to be the primary reaction. Although studies using UVC (254 nm) suggesting that the mutation hotspots are low repair efficiency regions could not completely explain the all hotspots, those using UVB and sunlight (UVB and UVA) revealed that CPD was efficiently produced even in such regions as not explained by studies with UVC alone. Therefore, the latter studies are conceivably reasonable since the skin cancer is induced by natural sunlight. Exon 5-8 DNA is completely methylated and the absorption coefficient of 5-methylcytosine is 5-6 times as large as that of cytosine at wavelength around 290 nm. These indicate the importance of UVB in mutation of mammalian cells possessing the ability to methylate DNA. (K.H.)

De novo SOX11 mutations cause Coffin-Siris syndrome.

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Tsurusaki, Yoshinori; Koshimizu, Eriko; Ohashi, Hirofumi; Phadke, Shubha; Kou, Ikuyo; Shiina, Masaaki; Suzuki, Toshifumi; Okamoto, Nobuhiko; Imamura, Shintaro; Yamashita, Michiaki; Watanabe, Satoshi; Yoshiura, Koh-ichiro; Kodera, Hirofumi; Miyatake, Satoko; Nakashima, Mitsuko; Saitsu, Hirotomo; Ogata, Kazuhiro; Ikegawa, Shiro; Miyake, Noriko; Matsumoto, Naomichi

2014-06-02

Coffin-Siris syndrome (CSS) is a congenital disorder characterized by growth deficiency, intellectual disability, microcephaly, characteristic facial features and hypoplastic nails of the fifth fingers and/or toes. We previously identified mutations in five genes encoding subunits of the BAF complex, in 55% of CSS patients. Here we perform whole-exome sequencing in additional CSS patients, identifying de novo SOX11 mutations in two patients with a mild CSS phenotype. sox11a/b knockdown in zebrafish causes brain abnormalities, potentially explaining the brain phenotype of CSS. SOX11 is the downstream transcriptional factor of the PAX6-BAF complex, highlighting the importance of the BAF complex and SOX11 transcriptional network in brain development.

Metabolic Alterations Caused by KRAS Mutations in Colorectal Cancer Contribute to Cell Adaptation to Glutamine Depletion by Upregulation of Asparagine Synthetase

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Kosuke Toda

2016-11-01

Full Text Available A number of clinical trials have shown that KRAS mutations of colorectal cancer (CRC can predict a lack of responses to anti-epidermal growth factor receptor–based therapy. Recently, there have been several studies to elucidate metabolism reprogramming in cancer. However, it remains to be investigated how mutated KRAS can coordinate the metabolic shift to sustain CRC tumor growth. In this study, we found that KRAS mutation in CRC caused alteration in amino acid metabolism. KRAS mutation causes a marked decrease in aspartate level and an increase in asparagine level in CRC. Using several human CRC cell lines and clinical specimens of primary CRC, we demonstrated that the expression of asparagine synthetase (ASNS, an enzyme that synthesizes asparagine from aspartate, was upregulated by mutated KRAS and that ASNS expression was induced by KRAS-activated signaling pathway, in particular PI3K-AKT-mTOR pathway. Importantly, we demonstrated that KRAS-mutant CRC cells could become adaptive to glutamine depletion through asparagine biosynthesis by ASNS and that asparagine addition could rescue the inhibited growth and viability of cells grown under the glutamine-free condition in vitro. Notably, a pronounced growth suppression of KRAS-mutant CRC was observed upon ASNS knockdown in vivo. Furthermore, combination of L-asparaginase plus rapamycin markedly suppressed the growth of KRAS-mutant CRC xenografts in vivo, whereas either L-asparaginase or rapamycin alone was not effective. These results indicate ASNS might be a novel therapeutic target against CRCs with mutated KRAS.

Splice, insertion-deletion and nonsense mutations that perturb the phenylalanine hydroxylase transcript cause phenylketonuria in India.

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Bashyam, Murali D; Chaudhary, Ajay K; Kiran, Manjari; Nagarajaram, Hampapathalu A; Devi, Radha Rama; Ranganath, Prajnya; Dalal, Ashwin; Bashyam, Leena; Gupta, Neerja; Kabra, Madhulika; Muranjan, Mamta; Puri, Ratna D; Verma, Ishwar C; Nampoothiri, Sheela; Kadandale, Jayarama S

2014-03-01

Phenylketonuria (PKU) is an autosomal recessive metabolic disorder caused by mutational inactivation of the phenylalanine hydroxylase (PAH) gene. Missense mutations are the most common PAH mutation type detected in PKU patients worldwide. We performed PAH mutation analysis in 27 suspected Indian PKU families (including 7 from our previous study) followed by structure and function analysis of specific missense and splice/insertion-deletion/nonsense mutations, respectively. Of the 27 families, disease-causing mutations were detected in 25. A total of 20 different mutations were identified of which 7 "unique" mutations accounted for 13 of 25 mutation positive families. The unique mutations detected exclusively in Indian PKU patients included three recurrent mutations detected in three families each. The 20 mutations included only 5 missense mutations in addition to 5 splice, 4 each nonsense and insertion-deletion mutations, a silent variant in coding region and a 3'UTR mutation. One deletion and two nonsense mutations were characterized to confirm significant reduction in mutant transcript levels possibly through activation of nonsense mediated decay. All missense mutations affected conserved amino acid residues and sequence and structure analysis suggested significant perturbations in the enzyme activity of respective mutant proteins. This is probably the first report of identification of a significantly low proportion of missense PAH mutations from PKU families and together with the presence of a high proportion of splice, insertion-deletion, and nonsense mutations, points to a unique PAH mutation profile in Indian PKU patients. © 2013 Wiley Periodicals, Inc.

Loss-of-function mutation in RUSC2 causes intellectual disability and secondary microcephaly.

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Alwadei, Ali H; Benini, Ruba; Mahmoud, Adel; Alasmari, Ali; Kamsteeg, Erik-Jan; Alfadhel, Majid

2016-12-01

Inherited aberrancies in intracellular vesicular transport are associated with a variety of neurological and non-neurological diseases. RUSC2 is a gene found on chromosome 9p13.3 that codes for iporin, a ubiquitous protein with high expression in the brain that interacts with Rab proteins (GTPases implicated in intracellular protein trafficking). Although mutations in Rab proteins have been described as causing brain abnormalities and intellectual disability, until now no disease-causing mutations in RUSC2 have ever been reported in humans. We describe, to our knowledge for the first time, three patients with inherited homozygous nonsense mutations identified in RUSC2 on whole-exome sequencing. All three patients had central hypotonia, microcephaly, and moderate to severe intellectual disability. Two patients had additional features of early-onset epilepsy and absence of the splenium. This report adds to the ever-expanding landscape of genetic causes of intellectual disability and increases our understanding of the cellular processes underlying this important neurological entity. © 2016 Mac Keith Press.

Similar phenotypes caused by mutations in OTOG and OTOGL

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Oonk, Anne M.M.; Leijendeckers, Joop M.; Huygen, Patrick L.M.; Schraders, Margit; del Campo, Miguel; del Castillo, Ignacio; Tekin, Mustafa; Feenstra, Ilse; Beynon, Andy J.; Kunst, Henricus P.M.; Snik, Ad F.M.; Kremer, Hannie; Admiraal, Ronald J.C.; Pennings, Ronald J.E.

2013-01-01

Objectives recently, OTOG and OTOGL were identified as human deafness genes. Currently, only four families are known to have autosomal recessive hearing loss based on mutations in these genes. Since the two genes code for proteins (otogelin and otogelin-like) that are strikingly similar in structure and localization in the inner ear, this study is focused on characterizing and comparing the hearing loss caused by mutations in these genes. Design To evaluate this type of hearing, an extensive set of audiometric and vestibular examinations was performed in the 13 patients from four families. Results all families show a flat to downsloping configuration of the audiogram with mild to moderate sensorineural hearing loss. Speech recognition scores remain good (>90%). Hearing loss is not significantly different in the four families and the psychophysical test results also do not differ between the families. Vestibular examinations show evidence for vestibular hyporeflexia. Conclusion since otogelin and otogelin-like are localized in the tectorial membrane, one could expect a cochlear conductive hearing loss, as was previously shown in DFNA13 (COL11A2) and DFNA8/12 (TECTA) patients. Results of psychophysical examinations, however, do not support this. Furthermore, the authors can conclude that there are no phenotypic differences between hearing loss based on mutations in OTOG or OTOGL. This phenotype description will facilitate counseling of hearing loss caused by defects in either of these two genes. PMID:24378291

Understanding the role of p53 in adaptive response to radiation-induced germline mutations

International Nuclear Information System (INIS)

Langlois, N.L.; Quinn, J.S.; Somers, C.M.; Boreham, D.R.; Mitchel, R.E.J.

2003-01-01

Full text: Radiation-induced adaptive response is now a widely studied area of radiation biology. Studies have demonstrated reduced levels of radiation-induced biological damage when an 'adaptive dose' is given before a higher 'challenge dose' compared to when the challenge dose is given alone. It has been shown in some systems to be a result of inducible cellular repair systems. The adaptive response has been clearly demonstrated in many model systems, however its impact on heritable effects in the mammalian germline has never been studied. Expanded Simple Tandem Repeat (ESTR) loci have been used as markers demonstrating that induced heritable mutations in mice follow a dose-response relationship. Recent data in our laboratory show preliminary evidence of radiation-induced adaptive response suppressing germline mutations at ESTR loci in wild type mice. The frequency of heritable mutations was significantly reduced when a priming dose of 0.1 Gy was given 24 hours prior to a 1 Gy acute challenging dose. We are now conducting a follow-up study to attempt to understand the mechanism of this adaptive response. P53 is known to play a significant role in governing apoptosis, DNA repair and cancer induction. In order to determine what function p53 has in the adaptive response for heritable mutations, we have mated radiation treated Trp53+/- male mice (C57Bl) to untreated, normal females (C57Bl). Using DNA fingerprinting, we are investigating the rate of inherited radiation-induced mutations on pre- and post-meiotic radiation-treated gametocytes by examining mutation frequencies in offspring DNA. If p53 is integral in the mechanism of adaptive response, we should not see an adaptive response in radiation-induced heritable mutations in these mice. This research is significant in that it will provide insight to understanding the mechanism behind radiation-induced adaptive response in the mammalian germline

Recurrent recessive mutation in deoxyguanosine kinase causes idiopathic noncirrhotic portal hypertension.

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Vilarinho, Sílvia; Sari, Sinan; Yilmaz, Güldal; Stiegler, Amy L; Boggon, Titus J; Jain, Dhanpat; Akyol, Gulen; Dalgic, Buket; Günel, Murat; Lifton, Richard P

2016-06-01

Despite advances in the diagnosis and management of idiopathic noncirrhotic portal hypertension, its pathogenesis remains elusive. Insight may be gained from study of early-onset familial idiopathic noncirrhotic portal hypertension, in which Mendelian mutations may account for disease. We performed exome sequencing of eight subjects from six kindreds with onset of portal hypertension of indeterminate etiology during infancy or childhood. Three subjects from two consanguineous families shared the identical rare homozygous p.N46S mutation in DGUOK, a deoxyguanosine kinase required for mitochondrial DNA replication; haplotype sharing demonstrated that the mutation in the two families was inherited from a remote common ancestor. All three affected subjects had stable portal hypertension with noncirrhotic liver disease for 6-16 years of follow-up. This mutation impairs adenosine triphosphate binding and reduces catalytic activity. Loss-of-function mutations in DGUOK have previously been implicated in cirrhosis and liver failure but not in isolated portal hypertension. Interestingly, treatment of patients with human immunodeficiency viral infection with the nucleoside analogue didanosine is known to cause portal hypertension in a subset of patients and lowers deoxyguanosine kinase levels in vitro; the current findings implicate these effects on deoxyguanosine kinase in the causal mechanism. Our findings provide new insight into the mechanisms mediating inherited and acquired noncirrhotic portal hypertension, expand the phenotypic spectrum of DGUOK deficiency, and provide a new genetic test for a specific cause of idiopathic noncirrhotic portal hypertension. (Hepatology 2016;63:1977-1986). © 2016 by the American Association for the Study of Liver Diseases.

A novel SERPINA1 mutation causing serum alpha(1-antitrypsin deficiency.

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Darren N Saunders

Full Text Available Mutations in the SERPINA1 gene can cause deficiency in the circulating serine protease inhibitor α(1-Antitrypsin (α(1AT. α(1AT deficiency is the major contributor to pulmonary emphysema and liver disease in persons of European ancestry, with a prevalence of 1 in 2500 in the USA. We present the discovery and characterization of a novel SERPINA1 mutant from an asymptomatic Middle Eastern male with circulating α(1AT deficiency. This 49 base pair deletion mutation (T379Δ, originally mistyped by IEF, causes a frame-shift replacement of the last sixteen α(1AT residues and adds an extra twenty-four residues. Functional analysis showed that the mutant protein is not secreted and prone to intracellular aggregation.

LPIN1 gene mutations: a major cause of severe rhabdomyolysis in early childhood

NARCIS (Netherlands)

Michot, Caroline; Hubert, Laurence; Brivet, Michèle; de Meirleir, Linda; Valayannopoulos, Vassili; Müller-Felber, Wolfgang; Venkateswaran, Ramesh; Ogier, Hélène; Desguerre, Isabelle; Altuzarra, Cécilia; Thompson, Elizabeth; Smitka, Martin; Huebner, Angela; Husson, Marie; Horvath, Rita; Chinnery, Patrick; Vaz, Frederic M.; Munnich, Arnold; Elpeleg, Orly; Delahodde, Agnès; de Keyzer, Yves; de Lonlay, Pascale

2010-01-01

Autosomal recessive LPIN1 mutations have been recently described as a novel cause of rhabdomyolysis in a few families. The purpose of the study was to evaluate the prevalence of LPIN1 mutations in patients exhibiting severe episodes of rhabdomyolysis in infancy. After exclusion of primary fatty acid

A Japanese Family with Central Hypothyroidism Caused by a Novel IGSF1 Mutation.

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Nishigaki, Satsuki; Hamazaki, Takashi; Fujita, Keinosuke; Morikawa, Shuntaro; Tajima, Toshihiro; Shintaku, Haruo

2016-12-01

Hemizygous mutations in the immunoglobulin superfamily member 1 (IGSF1) gene have been demonstrated to cause congenital central hypothyroidism in males. This study reports a family with a novel mutation in the IGSF1 gene located on the long arm of the X chromosome. A two-month-old boy was diagnosed with central hypothyroidism because of prolonged jaundice. A thyrotropin-releasing hormone (TRH) stimulation test indicated dysfunction in both the hypothalamus and the pituitary gland, and prompted the IGSF1 gene to be analyzed. The patient had a novel nonsense variant, c.2713C>T (p.Q905X), in exon 14 of the IGSF1 gene. Studies of the family revealed that the patient's sister and mother were heterozygous carriers of the IGSF1 mutation. The patient's maternal uncle carried the same mutation as the proband but had no overt symptoms. The mother and uncle started levothyroxine supplementation because of subclinical hypothyroidism. A novel mutation (c.2713C>T, p.Q905X) of the IGSF1 gene was identified that causes congenital central hypothyroidism in a Japanese family. The findings further expand the clinical heterogeneity of this entity.

Screening for mutations in the androgen receptor gene (AR) causing infertility in Syrian men using real-time PCR

International Nuclear Information System (INIS)

Madania, A.; Ghouri, I.; Abou-Alshamat, Gh.; Issa, M.; Al-Halabi, M.

2012-01-01

14 known point mutations in the androgen receptor gene (AR) causing male infertility were screened by real time PCR and by DNA sequencing, in order to identify point mutations in the AR gene causing infertility in azoospermic men. We screened 110 Syrian patients suffering from non-obstructive azoospermia with no chromosomal aberrations or AZF micro deletions. We discovered a new AR mutation, del 57Leu, described for the first time as a possible cause of male infertility. Furthermore, we found two patients with the Ala474Val mutation and one patient bearing the Pro390Ser mutation. Our results indicate that these mutations are significant markers for idiopathic male infertility in the Syrian society and in Mediterranean populations in general. (author)

P53 Gene Mutation as Biomarker of Radiation Induced Cell Injury and Genomic Instability

International Nuclear Information System (INIS)

Mukh-Syaifudin

2006-01-01

Gene expression profiling and its mutation has become one of the most widely used approaches to identify genes and their functions in the context of identify and categorize genes to be used as radiation effect markers including cell and tissue sensitivities. Ionizing radiation produces genetic damage and changes in gene expression that may lead to cancer due to specific protein that controlling cell proliferation altered the function, its expression or both. P53 protein encoded by p53 gene plays an important role in protecting cell by inducing growth arrest and or cell suicide (apoptosis) after deoxyribonucleic acid (DNA) damage induced by mutagen such as ionizing radiation. The mutant and thereby dysfunctional of this gene was found in more than 50% of various human cancers, but it is as yet unclear how p53 mutations lead to neoplastic development. Wild-type p53 has been postulated to play a role in DNA repair, suggesting that expression of mutant forms of p53 might alter cellular resistance to the DNA damage caused by radiation. Moreover, p53 is thought to function as a cell cycle checkpoint after irradiation, also suggesting that mutant p53 might change the cellular proliferative response to radiation. P53 mutations affect the cellular response to DNA damage, either by increasing DNA repair processes or, possibly, by increasing cellular tolerance to DNA damage. The association of p53 mutations with increased radioresistance suggests that alterations in the p53 gene might lead to oncogenic transformation. Current attractive model of carcinogenesis also showed that p53 gene is the major target of radiation. The majority of p53 mutations found so far is single base pair changes ( point mutations), which result in amino acid substitutions or truncated forms of the p53 protein, and are widely distributed throughout the evolutionary conserved regions of the gene. Examination of p53 mutations in human cancer also shows an association between particular carcinogens and

Homozygous STIL mutation causes holoprosencephaly and microcephaly in two siblings.

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Charlotte Mouden

Full Text Available Holoprosencephaly (HPE is a frequent congenital malformation of the brain characterized by impaired forebrain cleavage and midline facial anomalies. Heterozygous mutations in 14 genes have been identified in HPE patients that account for only 30% of HPE cases, suggesting the existence of other HPE genes. Data from homozygosity mapping and whole-exome sequencing in a consanguineous Turkish family were combined to identify a homozygous missense mutation (c.2150G>A; p.Gly717Glu in STIL, common to the two affected children. STIL has a role in centriole formation and has previously been described in rare cases of microcephaly. Rescue experiments in U2OS cells showed that the STIL p.Gly717Glu mutation was not able to fully restore the centriole duplication failure following depletion of endogenous STIL protein indicating the deleterious role of the mutation. In situ hybridization experiments using chick embryos demonstrated that expression of Stil was in accordance with a function during early patterning of the forebrain. It is only the second time that a STIL homozygous mutation causing a recessive form of HPE was reported. This result also supports the genetic heterogeneity of HPE and increases the panel of genes to be tested for HPE diagnosis.

Predicting the impact of Lynch syndrome-causing missense mutations from structural calculations.

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Sofie V Nielsen

2017-04-01

Full Text Available Accurate methods to assess the pathogenicity of mutations are needed to fully leverage the possibilities of genome sequencing in diagnosis. Current data-driven and bioinformatics approaches are, however, limited by the large number of new variations found in each newly sequenced genome, and often do not provide direct mechanistic insight. Here we demonstrate, for the first time, that saturation mutagenesis, biophysical modeling and co-variation analysis, performed in silico, can predict the abundance, metabolic stability, and function of proteins inside living cells. As a model system, we selected the human mismatch repair protein, MSH2, where missense variants are known to cause the hereditary cancer predisposition disease, known as Lynch syndrome. We show that the majority of disease-causing MSH2 mutations give rise to folding defects and proteasome-dependent degradation rather than inherent loss of function, and accordingly our in silico modeling data accurately identifies disease-causing mutations and outperforms the traditionally used genetic disease predictors. Thus, in conclusion, in silico biophysical modeling should be considered for making genotype-phenotype predictions and for diagnosis of Lynch syndrome, and perhaps other hereditary diseases.

Gamma-ray induced mutation breeding in tree fruit crops

International Nuclear Information System (INIS)

Ito, Yuji

1998-01-01

In many vegetatively propagated crops and tree fruit crops, spontaneous mutations have played an important role in the development of cultivars. Thus, induced mutation breeding has been thought to be a promising way to improve commercially important cultivars. At the Institute of Radiation Breeding (IRB), studies on induced mutation breeding of temperate zone fruit trees using gamma-rays have been performed since 1962. Black spot disease, caused by Alternaria alternata Japanese pear pathotype, is one of the most serious diseases of Japanese pear (Pyrus pyrifolia NAKAI var. culta NAKAI) in Japan. It is known that some Japanese pear cultivars are completely resistant to the disease. The pathogenic fungi produces host-specific toxins (named AK-toxin) (Tanaka 1993, Otani et al. 1973). The susceptibility of Japanese pear is controlled by a single dominant gene (Kozaki 1973). To improve the Japanese pear cultivar 'Nijisseiki', which is highly susceptible to black spot disease, young grafted plants of 'Nijisseiki' have been irradiated chronically in the Gamma Field of the IRB since 1962. In 1981, one twig of a tree planted at a distance of 53 m from the 60 Co source with an exposure rate of 0.138 Gy/day (20hr-irradiation) was selected as the first resistant mutant. It was designated as cultivar 'Gold Nijisseiki' and released in 1990. A selection method for mutants resistant to black spot disease using the pathogen produced toxin and pear leaf disks was established. It is a simple and stable selection method. Up to the present, three mutant cultivars resistant to black spot disease have been bred at the IRB by chronic and acute gamma-ray irradiation. They showed intermediate resistance compared with the completely resitan cultivar 'Choujuurou' and highly susceptible cultivar 'Nijisseiki'. We obtained some apple mutants resistant to alternaria leaf blotch disease using toxin and leaf disks and are also attempting to obtain mutant resistant to some disease in other temperate

Activity of the protector chlorophyllin or promoter of the genetic damage induced by the 1,2 dimethyl hydrazine

International Nuclear Information System (INIS)

Guerrero M, M.G.

2004-01-01

The chlorophyllin (CHLN) it is a porphyrin of soluble nutritious grade in water, derived of the chlorophyll that includes in their structure a copper atom. It has been reported that this pigment can act as anti mutagen, reducing the damage to the DNA caused by physical or chemical agents of direct or indirect action. Their anti carcinogen action has also been studied during the initiation phase induced for carcinogen as the aflatoxins and heterocyclic amines. In contrast the reports have increased on a probable promoter activity of the CHLN on the induced genetic damage. This effect was seen for the first time before the damage induced by alkylating agents in Salmonella. Recently it has been observed with the damage induced by gamma radiation, ENU and CrO 3 in somatic cells of the wing of Drosophila and in the induction of tumors for 1,2-dimethylhydrazine (DMH) in mice. Presently study is evaluated the protective effect or promoter of the CHLN before the genetic damage induced by 1,2-dimethylhydrazine, by means of the bioassay mutation and somatic recombination (SMART) in the wing of Drosophila melanogaster. Its were pretreated with CHLN or SAC to transheterocygotes larvas for two locus of the chromosome three mwh+/+flr 3 ; later on they are retarded the chronic treatment with DMH 0, 1, 2 and 3 days. It was measured the toxicity and the speed of development of the treated individuals. The wings of those adults that emerged were analyzed to register the number and the size of stains. The results indicated: differences in the viability of the individuals of the groups SAC + DMH vs CHLN + DMH only in the treated immediately after the pretreatment (DRT-0) that the CHLN doesn't modify the rate of the treated individuals development. The results of somatic mutation indicated that the CHLN has a protective effect only immediately after the pretreatment (DRT-0) however in DRT-1, 2 and 3 showed a promoter effect of genetic damage. (Author)

Mutations found in the Danish population causing Hereditary Hemorrhagic Telangiectasia

DEFF Research Database (Denmark)

Tørring, Pernille M; Brusgaard, Klaus

2011-01-01

University Hospital, Denmark HHT is an autosomal vascular disorder caused by mutations of either of three loci ENG, ACVLR1 or MADH4. HHT is characterised by recurrent nosebleeds, mucocutaneous telangiectases, and more severe visceral malformations. During the last decade the Danish HHT centre has...

c.376G>A mutation in WFS1 gene causes Wolfram syndrome without deafness.

Science.gov (United States)

Safarpour Lima, Behnam; Ghaedi, Hamid; Daftarian, Narsis; Ahmadieh, Hamid; Jamshidi, Javad; Khorrami, Mehdi; Noroozi, Rezvan; Sohrabifar, Nasim; Assarzadegan, Farhad; Hesami, Omid; Taghavi, Shaghayegh; Ahmadifard, Azadeh; Atakhorrami, Minoo; Rahimi-Aliabadi, Simin; Shahmohammadibeni, Neda; Alehabib, Elham; Andarva, Monavvar; Darvish, Hossein; Emamalizadeh, Babak

2016-02-01

Wolfram syndrome is one of the rare autosomal recessive, progressive, neurodegenerative disorders, characterized by diabetes mellitus and optic atrophy. Several other features are observed in patients including deafness, ataxia, and peripheral neuropathy. A gene called WFS1 is identified on chromosome 4p, responsible for Wolfram syndrome. We investigated a family consisted of parents and 8 children, which 5 of them have been diagnosed for Wolfram syndrome. WFS1 gene in all family members was sequenced for causative mutations. A mutation (c.376G>A, p.A126T) was found in all affected members in homozygous state and in both parents in heterozygous state. The bioinformatics analysis showed the deleterious effects of this nucleotide change on the structure and function of the protein product. As all of the patients in the family showed the homozygote mutation, and parents were both heterozygote, this mutation is probably the cause of the disease. We identified this mutation in homozygous state for the first time as Wolfram syndrome causation. We also showed that this mutation probably doesn't cause deafness in affected individuals. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A De Novo Mutation in Causes Generalized Dystonia in 2 Unrelated Children

Directory of Open Access Journals (Sweden)

Yasemin Gulcan Kurt MD

2016-03-01

Full Text Available Dystonia is often associated with the symmetrical basal ganglia lesions of Leigh syndrome. However, it has also been associated with mitochondrial ND mutations, with or without Leber hereditary optic neuropathy. The m.14459G>A mutation in ND6 causes dystonia with or without familial Leber hereditary optic neuropathy. We report heteroplasmic 14459G>A mutations in 2 unrelated children with nonmaternally inherited generalized dystonia and showing bilateral magnetic resonance imaging lesions in nucleus pallidus and putamen. Both children have reached their teenage years, and they are intellectually active, despite their motor problems.

IARS mutation causes prenatal death in Japanese Black cattle.

Science.gov (United States)

Hirano, Takashi; Matsuhashi, Tamako; Takeda, Kenji; Hara, Hiromi; Kobayashi, Naohiko; Kita, Kazuo; Sugimoto, Yoshikazu; Hanzawa, Kei

2016-09-01

Isoleucyl-tRNA synthetase (IARS) c.235G > C (p.V79L) is a causative mutation for a recessive disease called IARS disorder in Japanese black cattle. The disease is involved in weak calf syndrome and is characterized by low birth weight, weakness and poor suckling. The gestation period is often slightly extended, implying that intrauterine growth is retarded. In a previous analysis of 2597 artificial insemination (AI) procedures, we suggested that the IARS mutation might contribute toward an increase in the incidence of prenatal death. In this study, we extended this analysis to better clarify the association between the IARS mutation and prenatal death. The IARS genotypes of 92 animals resulting from crosses between carrier (G/C) × G/C were 27 normal (G/G), 55 G/C and 10 affected animals (C/C) (expected numbers: 23, 46 and 23, respectively). Compared to the expected numbers, there were significantly fewer affected animals in this population (P causes calf death, but also embryonic or fetal death. © 2016 Japanese Society of Animal Science.

The PTPN11 loss-of-function mutation Q510E-Shp2 causes hypertrophic cardiomyopathy by dysregulating mTOR signaling.

Science.gov (United States)

Schramm, Christine; Fine, Deborah M; Edwards, Michelle A; Reeb, Ashley N; Krenz, Maike

2012-01-01

The identification of mutations in PTPN11 (encoding the protein tyrosine phosphatase Shp2) in families with congenital heart disease has facilitated mechanistic studies of various cardiovascular defects. However, the roles of normal and mutant Shp2 in the developing heart are still poorly understood. Furthermore, it remains unclear how Shp2 loss-of-function (LOF) mutations cause LEOPARD Syndrome (also termed Noonan Syndrome with multiple lentigines), which is characterized by congenital heart defects such as pulmonary valve stenosis and hypertrophic cardiomyopathy (HCM). In normal hearts, Shp2 controls cardiomyocyte size by regulating signaling through protein kinase B (Akt) and mammalian target of rapamycin (mTOR). We hypothesized that Shp2 LOF mutations dysregulate this pathway, resulting in HCM. For our studies, we chose the Shp2 mutation Q510E, a dominant-negative LOF mutation associated with severe early onset HCM. Newborn mice with cardiomyocyte-specific overexpression of Q510E-Shp2 starting before birth displayed increased cardiomyocyte sizes, heart-to-body weight ratios, interventricular septum thickness, and cardiomyocyte disarray. In 3-mo-old hearts, interstitial fibrosis was detected. Echocardiographically, ventricular walls were thickened and contractile function was depressed. In ventricular tissue samples, signaling through Akt/mTOR was hyperactivated, indicating that the presence of Q510E-Shp2 led to upregulation of this pathway. Importantly, rapamycin treatment started shortly after birth rescued the Q510E-Shp2-induced phenotype in vivo. If rapamycin was started at 6 wk of age, HCM was also ameliorated. We also generated a second mouse model in which cardiomyocyte-specific Q510E-Shp2 overexpression started after birth. In contrast to the first model, these mice did not develop HCM. In summary, our studies establish a role for mTOR signaling in HCM caused by Q510E-Shp2. Q510E-Shp2 overexpression in the cardiomyocyte population alone was sufficient to

Induced mutations in citrus

International Nuclear Information System (INIS)

Spiegel-Roy, P.; Vardi, Aliza

1990-01-01

Full text: Parthenocarpic tendency is an important prerequisite for successful induction of seedlessness in breeding and especially in mutation breeding. A gene for asynapsis and accompanying seedless fruit has been found by us in inbred progeny of cv. 'Wilking'. Using budwood irradiation by gamma rays, seedless mutants of 'Eureka' and 'Villafranca' lemon (original clone of the latter has 25 seeds) and 'Minneola' tangelo have been obtained. Ovule sterility of the three mutants is nearly complete, with some pollen fertility still remaining. A semi-compact mutant of Shamouti orange has been obtained by irradiation. A programme for inducing seedlessness in easy peeling citrus varieties and selections has been initiated. (author)

Bartter and Gitelman syndromes: Spectrum of clinical manifestations caused by different mutations

Science.gov (United States)

Al Shibli, Amar; Narchi, Hassib

2015-01-01

Bartter and Gitelman syndromes (BS and GS) are inherited disorders resulting in defects in renal tubular handling of sodium, potassium and chloride. Previously considered as genotypic and phenotypic heterogeneous diseases, recent evidence suggests that they constitute a spectrum of disease caused by different genetic mutations with the molecular defects of chloride reabsorption originating at different sites of the nephron in each condition. Although they share some characteristic metabolic abnormalities such as hypokalemia, metabolic alkalosis, hyperplasia of the juxtaglomerular apparatus with hyperreninemia, hyperaldosteronism, the clinical and laboratory manifestations may not always allow distinction between them. Diuretics tests, measuring the changes in urinary fractional excretion of chloride from baseline after administration of either hydrochlorothiazide or furosemide show very little change (< 2.3%) in the fractional excretion of chloride from baseline in GS when compared with BS, except when BS is associated with KCNJ1 mutations where a good response to both diuretics exists. The diuretic test is not recommended for infants or young children with suspected BS because of a higher risk of volume depletion in such children. Clinical symptoms and biochemical markers of GS and classic form of BS (type III) may overlap and thus genetic analysis may specify the real cause of symptoms. However, although genetic analysis is available, its use remains limited because of limited availability, large gene dimensions, lack of hot-spot mutations, heavy workup time and costs involved. Furthermore, considerable overlap exists between the different genotypes and phenotypes. Although BS and GS usually have distinct presentations and are associated with specific gene mutations, there remains considerable overlap between their phenotypes and genotypes. Thus, they are better described as a spectrum of clinical manifestations caused by different gene mutations. PMID:26140272

Improvement of some ornamental plants by induced somatic mutations at National Botanical Research Institute

International Nuclear Information System (INIS)

Gupta, M.N.

1980-01-01

Research work on improvement of some ornamental plants by induced somatic mutations has been in progress at the National Botanical Research Institute, Lucknow, since 1964. The methods of treatments with gamma rays, detection, isolation and multiplication of induced somatic mutations have been given for Bougainvillea, Chrysanthemum, perennial Portulaca, rose and tuberose. During the last 15 years, a total of 38 new cultivars of different ornamentals evolved by gamna induced somatic mutations have been released. They include Bougainvillea 1; Chrysanthemum 28; perennial portulaca 6; rose 1 and tuberose 2. Descriptions of the original cultivars and their gamma induced mutants are given along with other pertinent details. (author)

Saccharomyces cerevisiae mutants with enhanced induced mutation and altered mitotic gene conversion.

Science.gov (United States)

Ivanov, E L; Kovaltzova, S V; Korolev, V G

1989-08-01

We have developed a method to isolate yeast (Saccharomyces cerevisiae) mutants with enhanced induced mutagenesis based on nitrous acid-induced reversion of the ade2-42 allele. Six mutants have been isolated and designated him (high induced mutagenesis), and 4 of them were studied in more detail. The him mutants displayed enhanced reversion of the ade2-42 allele, either spontaneous or induced by nitrous acid, UV light, and the base analog 6-N-hydroxylaminopurine, but not by gamma-irradiation. It is worth noting that the him mutants turned out not to be sensitive to the lethal effects of the mutagens used. The enhancement in mutation induced by nitrous acid, UV light, and 6-N-hydroxylaminopurine has been confirmed in a forward-mutation assay (induction of mutations in the ADE1, ADE2 genes). The latter agent revealed the most apparent differences between the him mutants and the wild-type strain and was, therefore, chosen for the genetic analysis of mutants, him mutations analyzed behaved as a single Mendelian trait; complementation tests indicated 3 complementation groups (HIM1, HIM2, and HIM3), each containing 1 mutant allele. Uracil-DNA glycosylase activity was determined in crude cell extracts, and no significant differences between the wild-type and him strains were detected. Spontaneous mitotic gene conversion at the ADE2 locus is altered in him1 strains, either increased or decreased, depending on the particular heteroallelic combination. Genetic evidence strongly suggests him mutations to be involved in a process of mismatch correction of molecular heteroduplexes.

Mutations in FUS cause FALS and SALS in French and French Canadian populations.

Science.gov (United States)

Belzil, V V; Valdmanis, P N; Dion, P A; Daoud, H; Kabashi, E; Noreau, A; Gauthier, J; Hince, P; Desjarlais, A; Bouchard, J-P; Lacomblez, L; Salachas, F; Pradat, P-F; Camu, W; Meininger, V; Dupré, N; Rouleau, G A

2009-10-13

The identification of mutations in the TARDBP and more recently the identification of mutations in the FUS gene as the cause of amyotrophic lateral sclerosis (ALS) is providing the field with new insight about the mechanisms involved in this severe neurodegenerative disease. To extend these recent genetic reports, we screened the entire gene in a cohort of 200 patients with ALS. An additional 285 patients with sporadic ALS were screened for variants in exon 15 for which mutations were previously reported. In total, 3 different mutations were identified in 4 different patients, including 1 3-bp deletion in exon 3 of a patient with sporadic ALS and 2 missense mutations in exon 15 of 1 patient with familial ALS and 2 patients with sporadic ALS. Our study identified sporadic patients with mutations in the FUS gene. The accumulation and description of different genes and mutations helps to develop a more comprehensive picture of the genetic events underlying amyotrophic lateral sclerosis.

Mutations in STX1B, encoding a presynaptic protein, cause fever-associated epilepsy syndromes

DEFF Research Database (Denmark)

Schubert, J.; Siekierska, A.; Langlois, M.

2014-01-01

Febrile seizures affect 2-4% of all children(1) and have a strong genetic component(2). Recurrent mutations in three main genes (SCN1A, SCN1B and GABRG2)(3-5) have been identified that cause febrile seizures with or without epilepsy. Here we report the identification of mutations in STX1B, encoding...... syntaxin-1B(6), that are associated with both febrile seizures and epilepsy. Whole-exome sequencing in independent large pedigrees(7,8) identified cosegregating STX1B mutations predicted to cause an early truncation or an in-frame insertion or deletion. Three additional nonsense or missense mutations...... and a de novo microdeletion encompassing STX1B were then identified in 449 familial or sporadic cases. Video and local field potential analyses of zebrafish larvae with antisense knockdown of stx1b showed seizure-like behavior and epileptiform discharges that were highly sensitive to increased temperature...

Novel NTRK1 mutations cause hereditary sensory and autonomic neuropathy type IV: demonstration of a founder mutation in the Turkish population.

Science.gov (United States)

Tüysüz, Beyhan; Bayrakli, Fatih; DiLuna, Michael L; Bilguvar, Kaya; Bayri, Yasar; Yalcinkaya, Cengiz; Bursali, Aysegul; Ozdamar, Elif; Korkmaz, Baris; Mason, Christopher E; Ozturk, Ali K; Lifton, Richard P; State, Matthew W; Gunel, Murat

2008-05-01

Hereditary sensory and autonomic neuropathy type IV (HSAN IV), or congenital insensitivity to pain with anhidrosis, is an autosomal recessive disorder characterized by insensitivity to noxious stimuli, anhidrosis from deinnervated sweat glands, and delayed mental and motor development. Mutations in the neurotrophic tyrosine kinase receptor type 1 (NTRK1), a receptor in the neurotrophin signaling pathway phosphorylated in response to nerve growth factor, are associated with this disorder. We identified six families from Northern Central Turkey with HSAN IV. We screened the NTRK1 gene for mutations in these families. Microsatellite and single nucleotide polymorphism (SNP) markers on the Affymetrix 250K chip platform were used to determine the haplotypes for three families harboring the same mutation. Screening for mutations in the NTRK1 gene demonstrated one novel frameshift mutation, two novel nonsense mutations, and three unrelated kindreds with the same splice-site mutation. Genotyping of the three families with the identical splice-site mutation revealed that they share the same haplotype. This report broadens the spectrum of mutations in NTRK1 that cause HSAN IV and demonstrates a founder mutation in the Turkish population.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation.

Science.gov (United States)

Ravindran, Ethiraj; Hu, Hao; Yuzwa, Scott A; Hernandez-Miranda, Luis R; Kraemer, Nadine; Ninnemann, Olaf; Musante, Luciana; Boltshauser, Eugen; Schindler, Detlev; Hübner, Angela; Reinecker, Hans-Christian; Ropers, Hans-Hilger; Birchmeier, Carmen; Miller, Freda D; Wienker, Thomas F; Hübner, Christoph; Kaindl, Angela M

2017-04-01

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation

Science.gov (United States)

Yuzwa, Scott A.; Hernandez-Miranda, Luis R.; Musante, Luciana; Boltshauser, Eugen; Schindler, Detlev; Hübner, Angela; Reinecker, Hans-Christian; Ropers, Hans-Hilger; Miller, Freda D.; Hübner, Christoph; Kaindl, Angela M.

2017-01-01

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder. PMID:28453519

Dystonia-Causing Mutations as a Contribution to the Etiology of Spasmodic Dysphonia.

Science.gov (United States)

de Gusmão, Claudio M; Fuchs, Tania; Moses, Andrew; Multhaupt-Buell, Trisha; Song, Phillip C; Ozelius, Laurie J; Franco, Ramon A; Sharma, Nutan

2016-10-01

Spasmodic dysphonia is a focal dystonia of the larynx with heterogeneous manifestations and association with familial risk factors. There are scarce data to allow precise understanding of etiology and pathophysiology. Screening for dystonia-causing genetic mutations has the potential to allow accurate diagnosis, inform about genotype-phenotype correlations, and allow a better understanding of mechanisms of disease. Cross-sectional study. Tertiary academic medical center. We enrolled patients presenting with spasmodic dysphonia to the voice clinic of our academic medical center. Data included demographics, clinical features, family history, and treatments administered. The following genes with disease-causing mutations previously associated with spasmodic dysphonia were screened: TOR1A (DYT1), TUBB4 (DYT4), and THAP1 (DYT6). Eighty-six patients were recruited, comprising 77% females and 23% males. A definite family history of neurologic disorder was present in 15% (13 of 86). Average age (± standard deviation) of symptom onset was 42.1 ± 15.7 years. Most (99%; 85 of 86) were treated with botulinum toxin, and 12% (11 of 86) received oral medications. Genetic screening was negative in all patients for the GAG deletion in TOR1A (DYT1) and in the 5 exons currently associated with disease-causing mutations in TUBB4 (DYT4). Two patients tested positive for novel/rare variants in THAP1 (DYT6). Genetic screening targeted at currently known disease-causing mutations in TOR1A, THAP1, and TUBB4 appears to have low diagnostic yield in sporadic spasmodic dysphonia. In our cohort, only 2 patients tested positive for novel/rare variants in THAP1. Clinicians should make use of genetic testing judiciously and in cost-effective ways. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

X-ray-induced mutations in Escherichia coli K-12 strains with altered DNA polymerase I activities

International Nuclear Information System (INIS)

Nagata, Yuki; Kawata, Masakado; Komura, Jun-ichiro; Ono, Tetsuya; Yamamoto, Kazuo

2003-01-01

Spectra of ionizing radiation mutagenesis were determined by sequencing X-ray-induced endogenous tonB gene mutations in Escherichia coli polA strains. We used two polA alleles, the polA1 mutation, defective for Klenow domain, and the polA107 mutation, defective for flap domain. We demonstrated that irradiation of 75 and 50 Gy X-rays could induce 3.8- and 2.6-fold more of tonB mutation in polA1 and polA107 strains, respectively, than spontaneous level. The radiation induced spectrum of 51 tonB mutations in polA1 and 51 in polA107 indicated that minus frameshift, A:T→T:A transversion and G:C→T:A transversion were the types of mutations increased. Previously, we have reported essentially the same X-ray-induced tonB mutation spectra in the wild-type strain. These results indicate that (1) X-rays can induce minus frameshift, A:T→T:A transversion and G:C→T:A transversion in E. coli and (2) presence or absence of polymerase I (PolI) of E. coli does not have any effects on the process of X-ray mutagenesis

FATP4 missense and nonsense mutations cause similar features in Ichthyosis Prematurity Syndrome

Directory of Open Access Journals (Sweden)

Dahl Niklas

2011-03-01

Full Text Available Abstract Background Ichthyosis Prematurity Syndrome (IPS is an autosomal recessive disorder characterized by premature birth, non-scaly ichthyosis and atopic manifestations. The disease was recently shown to be caused by mutations in the gene encoding the fatty acid transport protein 4 (FATP4 and a specific reduction in the incorporation of very long chain fatty acids (VLCFA into cellular lipids. Findings We screened probands from five families segregating IPS for mutations in the FATP4 gene. Four probands were compound heterozygous for four different mutations of which three are novel. Four patients were heterozygous and one patient homozygous for the previously reported non-sense mutation p.C168X (c.504c > a. All patients had clinical characteristics of IPS and a similar clinical course. Conclusions Missense mutations and non-sense mutations in FATP4 are associated with similar clinical features suggesting that missense mutations have a severe impact on FATP4 function. The results broaden the mutational spectrum in FATP4 associated with IPS for molecular diagnosis of and further functional analysis of FATP4.

Mutations in plasmalemma vesicle-associated protein cause severe syndromic protein-losing enteropathy.

Science.gov (United States)

Broekaert, Ilse Julia; Becker, Kerstin; Gottschalk, Ingo; Körber, Friederike; Dötsch, Jörg; Thiele, Holger; Altmüller, Janine; Nürnberg, Peter; Hünseler, Christoph; Cirak, Sebahattin

2018-04-16

Protein-losing enteropathy (PLE) is characterised by gastrointestinal protein leakage due to loss of mucosal integrity or lymphatic abnormalities. PLE can manifest as congenital diarrhoea and should be differentiated from other congenital diarrhoeal disorders. Primary PLEs are genetically heterogeneous and the underlying genetic defects are currently emerging. We report an infant with fatal PLE for whom we aimed to uncover the underlying pathogenic mutation. We performed whole exome sequencing (WES) for the index patient. Variants were classified based on the American College of Medical Genetics and Genomics guidelines. WES results and our detailed clinical description of the patient were compared with the literature. We discovered a novel homozygous stop mutation (c.988C>T, p.Q330*) in the Plasmalemma Vesicle-Associated Protein ( PLVAP ) gene in a newborn with fatal PLE, facial dysmorphism, and renal, ocular and cardiac anomalies. The Q330* mutation is predicted to result in complete loss of PLVAP protein expression leading to deletion of the diaphragms of endothelial fenestrae, resulting in plasma protein extravasation and PLE. Recently, another single homozygous stop mutation in PLVAP causing lethal PLE in an infant was reported. Our findings validate PLVAP mutations as a cause of syndromic PLE. Prenatal anomalies, severe PLE and syndromic features may guide the diagnosis of this rare disease. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Fifteen novel FBN1 mutations causing Marfan syndrome detected by heteroduplex analysis of genomic amplicons

Energy Technology Data Exchange (ETDEWEB)

Nijbroek, G.; Sood, S.; McIntosh, I. [John Hopkins Univ. School of Medicine, Baltimore, MD (United States)] [and others

1995-07-01

Mutations in the gene encoding fibrillin-1 (FBN1), a component of the extracellular microfibril, cause the Marfan syndrome (MFS). This statement is supported by the observations that the classic Marfan phenotype cosegregates with intragenic and/or flanking marker alleles in all families tested and that a significant number of FBN1 mutations have been identified in affected individuals. We have now devised a method to screen the entire coding sequence and flanking splice junctions of FBN1. On completion for a panel of nine probands with classic MFS, six new mutations were identified that accounted for disease in seven (78%) of nine patients. Nine additional new mutations have been characterized in the early stages of a larger screening project. These 15 mutations were equally distributed throughout the gene and, with one exception, were specific to single families. One-third of mutations created premature termination codons, and 6 of 15 substituted residues with putative significance for calcium finding to epidermal growth factor (EGF)-like domains. Mutations causing severe and rapidly progressive disease that presents in the neonatal period can occur in a larger region of the gene than previously demonstrated, and the nature of the mutation is as important a determinant as its location, in predisposing to this phenotype. 56 refs., 5 figs., 3 tabs.

Feeding the world with induced mutations and biotechnology

International Nuclear Information System (INIS)

Mohan Jain, S.

2002-01-01

The paper discussed the following subjects: biotechnology - somaclonal variation, somatic embryogenesis, somatic cell hybridization; induced mutations - in banana, ornamental plants; in vitro mutagenesis; T-DNA insertional mutagenesis. Suggestions for improving biotechnology in the developing countries also presented in the paper

Loss-of-activity-mutation in the cardiac chloride-bicarbonate exchanger AE3 causes short QT syndrome

DEFF Research Database (Denmark)

Thorsen, Kasper; Dam, Vibeke S.; Kjaer-Sorensen, Kasper

2017-01-01

unrelated families with SQTS. The mutation causes reduced surface expression of AE3 and reduced membrane bicarbonate transport. Slc4a3 knockdown in zebrafish causes increased cardiac pHi, short QTc, and reduced systolic duration, which is rescued by wildtype but not mutated SLC4A3. Mechanistic analyses...

[Novel CHST6 compound heterozygous mutations cause macular corneal dystrophy in a Chinese family].

Science.gov (United States)

Qi, Yan-hua; Dang, Xiu-hong; Su, Hong; Zhou, Nan; Liang, Ting; Wang, Zheng; Huang, Shang-zhi

2010-02-01

The aim of this study was to identify mutations of CHST6 gene in a Chinese family with macular corneal dystrophy (MCD) and to investigate the histopathological changes of MCD. Corneal button of the proband was obtained from penetrating keratoplasty for the treatment of severe corneal dystrophy. The sections and ultrathin sections of this specimen were examined under light microscope and transmission electron microscope (TEM). Genomic DNA was extracted from leukocytes in peripheral blood from the family members. The coding region of CHST6 was amplified by polymerase chain reaction (PCR). The PCR products were analyzed by direct sequencing and restriction enzyme digestion. Histochemical study revealed positive results of colloidal iron stain. TEM revealed enlargement of smooth endoplasmic reticulum and the presence of intracytoplasmic vacuoles. Two mutations, Q298X Y358H, were identified in exon 3 of CHST6. Three patients were compound heterozygotes of these two mutations. The C892T transversion occurred at codon 298 turned the codon of glutamine to a stop codon; the T1072C transversion occurred at codon 358 caused a missense mutation, tyrosine to histidine. All six unaffected family members were heterozygotes. These two mutations were not detected in any of the 100 control subjects. The novel compound heterozygous mutation results in loss of CHST6 function and causes the occurrence of MCD. This is the first report of this gene mutation.

Unstable mutations: cause of some neurological hereditary diseases

International Nuclear Information System (INIS)

Cuenca Berger, P.; Morales Montero, F.

1999-01-01

Unstable mutations or amplification of triplets constitute a kind of genetic alteration discovered during the last decade. They had been found inside or near genes important for the normal neurological function of the human being. In some cases, the presence of the amplification causes the inactivation of the gene or the synthesis of a new product which functions different from the original protein. Some common characteristics of diseases caused by the amplification of triplets are that it affects the nervous system and are degenerative in nature. The expression of the manifestations varies according to age. Most of them show genetic anticipation in which the severity of the manifestations increases with each generation and appear at an earlier age. In most cases, the severity of the symptoms is correlated positively to the size of the amplification. The diagnosis of an affected individual in a family may indicate the presence of an altered gene in other relatives. These relatives may not present evident signs of the illness either because it is of late onset or because they carry premutations. The molecular diagnosis of these mutations is important to estimate the risk of developing the disease and/or of transmitting the illness to the descendants and to eliminate the fears of healthy relatives who have inherited normal copies of the gene. (Author) [es

Phenotype and genotype in 52 patients with Rubinstein-Taybi syndrome caused by EP300 mutations.

Science.gov (United States)

Fergelot, Patricia; Van Belzen, Martine; Van Gils, Julien; Afenjar, Alexandra; Armour, Christine M; Arveiler, Benoit; Beets, Lex; Burglen, Lydie; Busa, Tiffany; Collet, Marie; Deforges, Julie; de Vries, Bert B A; Dominguez Garrido, Elena; Dorison, Nathalie; Dupont, Juliette; Francannet, Christine; Garciá-Minaúr, Sixto; Gabau Vila, Elisabeth; Gebre-Medhin, Samuel; Gener Querol, Blanca; Geneviève, David; Gérard, Marion; Gervasini, Cristina Giovanna; Goldenberg, Alice; Josifova, Dragana; Lachlan, Katherine; Maas, Saskia; Maranda, Bruno; Moilanen, Jukka S; Nordgren, Ann; Parent, Philippe; Rankin, Julia; Reardon, Willie; Rio, Marlène; Roume, Joëlle; Shaw, Adam; Smigiel, Robert; Sojo, Amaia; Solomon, Benjamin; Stembalska, Agnieszka; Stumpel, Constance; Suarez, Francisco; Terhal, Paulien; Thomas, Simon; Touraine, Renaud; Verloes, Alain; Vincent-Delorme, Catherine; Wincent, Josephine; Peters, Dorien J M; Bartsch, Oliver; Larizza, Lidia; Lacombe, Didier; Hennekam, Raoul C

2016-12-01

Rubinstein-Taybi syndrome (RSTS) is a developmental disorder characterized by a typical face and distal limbs abnormalities, intellectual disability, and a vast number of other features. Two genes are known to cause RSTS, CREBBP in 60% and EP300 in 8-10% of clinically diagnosed cases. Both paralogs act in chromatin remodeling and encode for transcriptional co-activators interacting with >400 proteins. Up to now 26 individuals with an EP300 mutation have been published. Here, we describe the phenotype and genotype of 42 unpublished RSTS patients carrying EP300 mutations and intragenic deletions and offer an update on another 10 patients. We compare the data to 308 individuals with CREBBP mutations. We demonstrate that EP300 mutations cause a phenotype that typically resembles the classical RSTS phenotype due to CREBBP mutations to a great extent, although most facial signs are less marked with the exception of a low-hanging columella. The limb anomalies are more similar to those in CREBBP mutated individuals except for angulation of thumbs and halluces which is very uncommon in EP300 mutated individuals. The intellectual disability is variable but typically less marked whereas the microcephaly is more common. All types of mutations occur but truncating mutations and small rearrangements are most common (86%). Missense mutations in the HAT domain are associated with a classical RSTS phenotype but otherwise no genotype-phenotype correlation is detected. Pre-eclampsia occurs in 12/52 mothers of EP300 mutated individuals versus in 2/59 mothers of CREBBP mutated individuals, making pregnancy with an EP300 mutated fetus the strongest known predictor for pre-eclampsia. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A challenge to mutation theory of radiation carcinogenesis

International Nuclear Information System (INIS)

Watanabe, Masami

2006-01-01

This paper presents an objection against the commonly accepted mutation theory in radiation carcinogenesis. First, author's studies of X-ray irradiated syrian hamster embryo (SHE) cells on malignant morphological changes and mutational change of HGPRT gene showed that the changing patterns were quite different, and as well, other studies in mice gave the essentially similar results. Thus radiation-induced carcinogenesis in cells does not simply occur by an accumulation of radiation-induced mutation. Second, as cultured cells usually used for oncogenesis studies already have the infinitively proliferative ability, the author used the primary cell culture obtained from the rodent embryo. Even those cells became immortal to be cancerous after repeated culture passage with the higher frequency of 10 3 -10 4 relative to somatic cell mutation. Cells thus seem to be easily changeable to cancerous ones. Bystander effect can cause transformation in non-irradiated cells and genetic instability by radiation can form the potentially unstable chromatin region, which induces telomere instability. The author has found that, while short-lived radicals yielded by X-ray irradiation attack DNA to induce cell death and chromosome aberration, long-lived radicals in biomolecules do not, but can cause mutation and carcinogenesis, which are reduced by vitamine C supplementation. The author concludes that the primary target in the radiation carcinogenesis in cells and even in the whole individuals is conceivably protein and not DNA. (T.I.)

De novo mutations in synaptic transmission genes including DNM1 cause epileptic encephalopathies

DEFF Research Database (Denmark)

2014-01-01

in five individuals and de novo mutations in GABBR2, FASN, and RYR3 in two individuals each. Unlike previous studies, this cohort is sufficiently large to show a significant excess of de novo mutations in epileptic encephalopathy probands compared to the general population using a likelihood analysis (p...... = 8.2 × 10(-4)), supporting a prominent role for de novo mutations in epileptic encephalopathies. We bring statistical evidence that mutations in DNM1 cause epileptic encephalopathy, find suggestive evidence for a role of three additional genes, and show that at least 12% of analyzed individuals have...... analyzed exome-sequencing data of 356 trios with the "classical" epileptic encephalopathies, infantile spasms and Lennox Gastaut syndrome, including 264 trios previously analyzed by the Epi4K/EPGP consortium. In this expanded cohort, we find 429 de novo mutations, including de novo mutations in DNM1...

Induced mutations and marker assisted breeding in soybean

Energy Technology Data Exchange (ETDEWEB)

Chotechuen, Somsong [Prachinburi Rice Research Center, Prachinburi (Thailand); Srisombun, Somsak [Department of Agriculture, Field Crops Research Institute, Bangkok (Thailand); Lamseejan, Siranut [Kasetsart Univ., Department of Applied Radiation and Isotopes, Bangkok (Thailand)

2002-02-01

Soybean is one of the important crops in Thailand. Constraints to soybean production include low yield potential, susceptibility to diseases and insects, and non-adoption of appropriate management practices. Mutation induction has been used to improve soybean yield and resistance to major diseases such as rust, purple seed, crinkle leaf, anthracnose and green seed. This paper reviews previous work and achievements of induced mutations in soybean. Successful examples are the release of a soybean variety, Doi Kham, and the development of a mutant CM 60-10kr-71; both are resistant to rust disease. The paper also gives example of the use of soybean SSR markers to identify QTL associated with pod shattering, and emphasizes the integration of mutation techniques and marker assisted selection for soybean improvement. (author)

Utilization of induced mutations in improving legumes in Egypt

International Nuclear Information System (INIS)

Abo-Hegazi, A. M. T.

1993-01-01

More than one hundred articles published by Egyptian research workers dealing with the improvement of some seed-legumes through radiation, radioisotopes, chemical mutagens and induced mutations are briefly summarized and discussed from the point of view of a mutation breeder working in this field since 1961. Articles on faba bean (Vicia faba L.), soybean (Glycine Max L.), lentils (Lens culinaris), chick-pea (Cicer arietinum L.), lupin (Lupinus termis), peas=pea (Pisum sativum L.), cowpea (Vigna sinensis, savi), and fenugreek-helba (Trigonella foenum gracum L.) are reviewed. A very few number of promising mutations have been induced. However, none of them are utilized neither in conventional breeding programs nor as cultivars. This may be due to the lack of central plans and organization between efforts or research work being carried in various institutions. Joint plants and cooperation between research institutions, not only in Egypt but also among the Arab countries, are required in this field which may help in closing the wide gab between production and consumption os seed legumes. (author)

SKIV2L Mutations Cause Syndromic Diarrhea, or Trichohepatoenteric Syndrome

Science.gov (United States)

Fabre, Alexandre; Charroux, Bernard; Martinez-Vinson, Christine; Roquelaure, Bertrand; Odul, Egritas; Sayar, Ersin; Smith, Hilary; Colomb, Virginie; Andre, Nicolas; Hugot, Jean-Pierre; Goulet, Olivier; Lacoste, Caroline; Sarles, Jacques; Royet, Julien; Levy, Nicolas; Badens, Catherine

2012-01-01

Syndromic diarrhea (or trichohepatoenteric syndrome) is a rare congenital bowel disorder characterized by intractable diarrhea and woolly hair, and it has recently been associated with mutations in TTC37. Although databases report TTC37 as being the human ortholog of Ski3p, one of the yeast Ski-complex cofactors, this lead was not investigated in initial studies. The Ski complex is a multiprotein complex required for exosome-mediated RNA surveillance, including the regulation of normal mRNA and the decay of nonfunctional mRNA. Considering the fact that TTC37 is homologous to Ski3p, we explored a gene encoding another Ski-complex cofactor, SKIV2L, in six individuals presenting with typical syndromic diarrhea without variation in TTC37. We identified mutations in all six individuals. Our results show that mutations in genes encoding cofactors of the human Ski complex cause syndromic diarrhea, establishing a link between defects of the human exosome complex and a Mendelian disease. PMID:22444670

A novel MKRN3 missense mutation causing familial precocious puberty.

Science.gov (United States)

de Vries, L; Gat-Yablonski, G; Dror, N; Singer, A; Phillip, M

2014-12-01

Central precocious puberty may be familial in about a quarter of the idiopathic cases. However, little is known about the genetic causes responsible for the disorder. In this report we describe a family with central precocious puberty associated with a mutation in the makorin RING-finger protein 3 (MKRN3) gene. A novel missense mutation (p.H420Q) in the imprinted MKRN3 gene was identified in the four affected siblings, in their unaffected father and in his affected mother. An in silico mutant MKRN3 model predicts that the mutation p.H420Q leads to reduced zinc binding and, subsequently, impaired RNA binding. These findings support the fundamental role of the MKRN3 protein in determining pubertal timing. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Male-fertility-restorer mutation induced by x-rays in wheat

International Nuclear Information System (INIS)

Sasaki, Mutsuo; Nakata, Noboru; Yasumuro, Yoshimasa

1982-01-01

Some male-fertility restoring mutants were obtained by X-irradiation (20 or 25 kR, 105.3 R/min) of the air-dried seed of cytoplasmic male-sterile (cms) wheat, (timopheevi)-Bison. These X-ray induced male-fertility restoring mutant (Rfx) lines restored the male fertility of F 1 hybrids with cms (timopheevi)-Bison as female, but their fertility-restoring ability was not superior to that of known restorers such as Gironde, Primepi, and (t)-H30. The Rfx lines were also different from the original (timopheevi)-Bison, in many characters. The study on these multicharacter mutations with 18 morphological and physiological characters of the 7 M 6 line groups derived from the 7M 2 plants, revealed that each M 2 progenitor plant of each M 6 line-group had the mutant genes for almost all these characters, and that the mutation for at least half of all these mutant genes was induced in the original cell of the gamates of each X-irradiated M 1 plant. Considering the multicharacter mutations of the Rfx lines, a backcross method for the mutation breeding of male-fertility restorers in wheat was proposed. (Kaihara, S.)

Effect of hsm mutations enhancing spontaneous mutability on induced mutagenesis and mitotic recombination in Saccharomyces cerevisiae yeast

International Nuclear Information System (INIS)

Fedorova, I.V.; Koval'tsova, S.V.; Ivanov, E.L.

1993-01-01

The authors have studied the effect of five nonallelic hms1-hms5 mutations on the incidence of direct mutations in loci ADE1 and ADE2, induced by UV-radiation, 6-hydroxyl-aminopurine, and nitrosomethylurea. All hms mutants were found to be insensitive to the lethal action of these mutagens. The frequency of UV-induced mutations to adenine dependence was increased in mutants hsm2-1, hsm3-1, hsm5-1, and particularly in hsm1-1, but remained unchanged in hsm4-1 compared to HSM. Mutagenesis induced by 6-hydroxylaminopurine was increased in all mutants studied, particularly in mutant hsm3-1. The authors did not detect any appreciable effect of hsm mutations on mutagenesis induced by nitrosomethylurea. The frequency of spontaneous mitotic conversion to prototrophy was studied in diploids heteroallelic to gene ADE2 and homo- and heterozygous for hsm mutations. Mutation hsm5-1 considerably increased the frequency of conversion for all heteroalleles studied, mutations hsm1-1 and hsm3-1 also considerably increased the conversion frequency, while mutations hsm1-1 and hsm4-1 had little effect on this process. The study of the properties of hsm mutations revealed joint genetic control of spontaneous and induced mutagenesis and recombination in yeast. The possibility that hsm mutations belong to the class of mutations impairing correction of unpaired DNA bases is discussed. 25 refs., 3 figs., 3 tabs

Characterization of phospholipase C gamma enzymes with gain-of-function mutations.

Science.gov (United States)

Everett, Katy L; Bunney, Tom D; Yoon, Youngdae; Rodrigues-Lima, Fernando; Harris, Richard; Driscoll, Paul C; Abe, Koichiro; Fuchs, Helmut; de Angelis, Martin Hrabé; Yu, Philipp; Cho, Wohnwa; Katan, Matilda

2009-08-21

Phospholipase C gamma isozymes (PLC gamma 1 and PLC gamma 2) have a crucial role in the regulation of a variety of cellular functions. Both enzymes have also been implicated in signaling events underlying aberrant cellular responses. Using N-ethyl-N-nitrosourea (ENU) mutagenesis, we have recently identified single point mutations in murine PLC gamma 2 that lead to spontaneous inflammation and autoimmunity. Here we describe further, mechanistic characterization of two gain-of-function mutations, D993G and Y495C, designated as ALI5 and ALI14. The residue Asp-993, mutated in ALI5, is a conserved residue in the catalytic domain of PLC enzymes. Analysis of PLC gamma 1 and PLC gamma 2 with point mutations of this residue showed that removal of the negative charge enhanced PLC activity in response to EGF stimulation or activation by Rac. Measurements of PLC activity in vitro and analysis of membrane binding have suggested that ALI5-type mutations facilitate membrane interactions without compromising substrate binding and hydrolysis. The residue mutated in ALI14 (Tyr-495) is within the spPH domain. Replacement of this residue had no effect on folding of the domain and enhanced Rac activation of PLC gamma 2 without increasing Rac binding. Importantly, the activation of the ALI14-PLC gamma 2 and corresponding PLC gamma 1 variants was enhanced in response to EGF stimulation and bypassed the requirement for phosphorylation of critical tyrosine residues. ALI5- and ALI14-type mutations affected basal activity only slightly; however, their combination resulted in a constitutively active PLC. Based on these data, we suggest that each mutation could compromise auto-inhibition in the inactive PLC, facilitating the activation process; in addition, ALI5-type mutations could enhance membrane interaction in the activated state.

Heterozygous Mutations in TREX1 Cause Familial Chilblain Lupus and Dominant Aicardi-Goutières Syndrome

Science.gov (United States)

Rice, Gillian; Newman, William G.; Dean, John; Patrick, Teresa; Parmar, Rekha; Flintoff, Kim; Robins, Peter; Harvey, Scott; Hollis, Thomas; O’Hara, Ann; Herrick, Ariane L.; Bowden, Andrew P.; Perrino, Fred W.; Lindahl, Tomas; Barnes, Deborah E.; Crow, Yanick J.

2007-01-01

TREX1 constitutes the major 3′→5′ DNA exonuclease activity measured in mammalian cells. Recently, biallelic mutations in TREX1 have been shown to cause Aicardi-Goutières syndrome at the AGS1 locus. Interestingly, Aicardi-Goutières syndrome shows overlap with systemic lupus erythematosus at both clinical and pathological levels. Here, we report a heterozygous TREX1 mutation causing familial chilblain lupus. Additionally, we describe a de novo heterozygous mutation, affecting a critical catalytic residue in TREX1, that results in typical Aicardi-Goutières syndrome. PMID:17357087

A novel CYP27B1 mutation causes a feline vitamin D-dependent rickets type IA.

Science.gov (United States)

Grahn, Robert A; Ellis, Melanie R; Grahn, Jennifer C; Lyons, Leslie A

2012-08-01

A 12-week-old domestic cat presented at a local veterinary clinic with hypocalcemia and skeletal abnormalities suggestive of rickets. Osteomalacia (rickets) is a disease caused by impaired bone mineralization leading to an increased prevalence of fractures and deformity. Described in a variety of species, rickets is most commonly caused by vitamin D or calcium deficiencies owing to both environmental and or genetic abnormalities. Vitamin D-dependent rickets type 1A (VDDR-1A) is a result of the enzymatic pathway defect caused by mutations in the 25-hydroxyvitamin D(3)-1-alpha-hydroxylase gene [cytochrome P27 B1 (CYP27B1)]. Calcitriol, the active form of vitamin D(3), regulates calcium homeostasis, which requires sufficient dietary calcium availability and correct hormonal function for proper bone growth and maintenance. Patient calcitriol concentrations were low while calcidiol levels were normal suggestive of VDDR-1A. The entire DNA coding sequencing of CYP27B1 was evaluated. The affected cat was wild type for previously identified VDDR-1A causative mutations. However, six novel mutations were identified, one of which was a nonsense mutation at G637T in exon 4. The exon 4 G637T nonsense mutation results in a premature protein truncation, changing a glutamic acid to a stop codon, E213X, likely causing the clinical presentation of rickets. The previously documented genetic mutation resulting in feline VDDR-1A rickets, as well as the case presented in this research, result from novel exon 4 CYP27B1 mutations, thus exon 4 should be the initial focus of future sequencing efforts.

Achievements and trends of using induced mutations in crop improvement

International Nuclear Information System (INIS)

Nichterlein, K.; Maluszynski, M.; ); Bohlmann, H.; Nielen, S.; )

2000-01-01

Mutation techniques have been employed for the genetic improvement of crops and ornamentals leading to the official release of more than 2200 improved varieties. Some of them have made a major impact on crop productivity and achieved great economic success. Induced mutations play an important role in plant genome research to understand the function of genes aiming to improve food security and diversity. (author)

Reciprocal sign epistasis between frequently experimentally evolved adaptive mutations causes a rugged fitness landscape.

Directory of Open Access Journals (Sweden)

Daniel J Kvitek

2011-04-01

Full Text Available The fitness landscape captures the relationship between genotype and evolutionary fitness and is a pervasive metaphor used to describe the possible evolutionary trajectories of adaptation. However, little is known about the actual shape of fitness landscapes, including whether valleys of low fitness create local fitness optima, acting as barriers to adaptive change. Here we provide evidence of a rugged molecular fitness landscape arising during an evolution experiment in an asexual population of Saccharomyces cerevisiae. We identify the mutations that arose during the evolution using whole-genome sequencing and use competitive fitness assays to describe the mutations individually responsible for adaptation. In addition, we find that a fitness valley between two adaptive mutations in the genes MTH1 and HXT6/HXT7 is caused by reciprocal sign epistasis, where the fitness cost of the double mutant prohibits the two mutations from being selected in the same genetic background. The constraint enforced by reciprocal sign epistasis causes the mutations to remain mutually exclusive during the experiment, even though adaptive mutations in these two genes occur several times in independent lineages during the experiment. Our results show that epistasis plays a key role during adaptation and that inter-genic interactions can act as barriers between adaptive solutions. These results also provide a new interpretation on the classic Dobzhansky-Muller model of reproductive isolation and display some surprising parallels with mutations in genes often associated with tumors.

Homozygous ARHGEF2 mutation causes intellectual disability and midbrain-hindbrain malformation.

Directory of Open Access Journals (Sweden)

Ethiraj Ravindran

2017-04-01

Full Text Available Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder.

FAM20A mutations can cause enamel-renal syndrome (ERS.

Directory of Open Access Journals (Sweden)

Shih-Kai Wang

Full Text Available Enamel-renal syndrome (ERS is an autosomal recessive disorder characterized by severe enamel hypoplasia, failed tooth eruption, intrapulpal calcifications, enlarged gingiva, and nephrocalcinosis. Recently, mutations in FAM20A were reported to cause amelogenesis imperfecta and gingival fibromatosis syndrome (AIGFS, which closely resembles ERS except for the renal calcifications. We characterized three families with AIGFS and identified, in each case, recessive FAM20A mutations: family 1 (c.992G>A; g.63853G>A; p.Gly331Asp, family 2 (c.720-2A>G; g.62232A>G; p.Gln241_Arg271del, and family 3 (c.406C>T; g.50213C>T; p.Arg136* and c.1432C>T; g.68284C>T; p.Arg478*. Significantly, a kidney ultrasound of the family 2 proband revealed nephrocalcinosis, revising the diagnosis from AIGFS to ERS. By characterizing teeth extracted from the family 3 proband, we demonstrated that FAM20A(-/- molars lacked true enamel, showed extensive crown and root resorption, hypercementosis, and partial replacement of resorbed mineral with bone or coalesced mineral spheres. Supported by the observation of severe ectopic calcifications in the kidneys of Fam20a null mice, we conclude that FAM20A, which has a kinase homology domain and localizes to the Golgi, is a putative Golgi kinase that plays a significant role in the regulation of biomineralization processes, and that mutations in FAM20A cause both AIGFS and ERS.

Nephrocalcinosis in Amelogenesis Imperfecta Caused by the FAM20A Mutation.

Science.gov (United States)

Koruyucu, Mine; Seymen, Figen; Gencay, Genco; Gencay, Koray; Tuna, Elif Bahar; Shin, Teo Jeon; Hyun, Hong-Keun; Kim, Young-Jae; Kim, Jung-Wook

2018-01-01

Enamel-renal syndrome is characterized by nephrocalcinosis, enamel defects, gingival hyperplasia and eruption failures. It has been recently identified that recessive mutations in the FAM20A gene result in amelogenesis imperfecta (AI)-gingival fibromatosis. The aim of this research to determine whether AI patients with known -FAM20A mutations also have nephrocalcinosis. Complete oral and radiological examinations were performed for all participating family members. Renal examinations were performed using ultrasound. The teeth were evaluated for severe loss, and multiple eruption failures were evident from the clinical and radiological examinations. Unexpected extensive and fast crown resorption was found by radiological examination. Renal ultrasound revealed bilateral nephrocalcinosis in both affected individuals. Recessive FAM20A mutations can cause nephrocalcinosis in addition to the oral phenotype. AI patients with similar clinical phenotypes and FAM20A mutations should be examined for nephropathy even if they lack pertinent symptoms. Nephrology referral is warranted for patients who have clinical phenotypes related to AI-gingival fibromatosis even if they are not symptomatic. © 2018 S. Karger AG, Basel.

Axonal transport of TDP-43 mRNA granules in neurons is impaired by ALS-causing mutations

Science.gov (United States)

Carrasco, Monica A.; Williams, Luis A.; Winborn, Christina S.; Han, Steve S. W.; Kiskinis, Evangelos; Winborn, Brett; Freibaum, Brian D.; Kanagaraj, Anderson; Clare, Alison J.; Badders, Nisha M.; Bilican, Bilada; Chaum, Edward; Chandran, Siddharthan; Shaw, Christopher E.; Eggan, Kevin C.; Maniatis, Tom; Taylor, J. Paul

2014-01-01

Summary The RNA binding protein TDP-43 regulates RNA metabolism at multiple levels, including transcription, RNA splicing, and mRNA stability. TDP-43 is a major component of the cytoplasmic inclusions characteristic of amyotrophic lateral sclerosis and some types of frontotemporal lobar degeneration. The importance of TDP-43 in disease is underscored by the fact that dominant missense mutations are sufficient to cause disease, although the role of TDP-43 in pathogenesis is unknown. Here we show that TDP-43 forms cytoplasmic mRNP granules that undergo bidirectional, microtubule-dependent transport in neurons in vitro and in vivo and facilitate delivery of target mRNA to distal neuronal compartments. TDP-43 mutations impair this mRNA transport function in vivo and in vitro, including in stem cell-derived motor neurons from ALS patients bearing any one of three different TDP-43 ALS-causing mutations. Thus, TDP43 mutations that cause ALS lead to partial loss of a novel cytoplasmic function of TDP-43. PMID:24507191

Molecular nature of mutations induced by high-LET irradiation with argon and carbon ions in Arabidopsis thaliana

International Nuclear Information System (INIS)

Hirano, Tomonari; Kazama, Yusuke; Ohbu, Sumie; Shirakawa, Yuki; Liu Yang; Kambara, Tadashi; Fukunishi, Nobuhisa; Abe, Tomoko

2012-01-01

Linear energy transfer (LET) is an important parameter to be considered in heavy-ion mutagenesis. However, in plants, no quantitative data are available on the molecular nature of the mutations induced with high-LET radiation above 101–124 keV μm −1 . In this study, we irradiated dry seeds of Arabidopsis thaliana with Ar and C ions with an LET of 290 keV μm −1 . We analyzed the DNA alterations caused by the higher-LET radiation. Mutants were identified from the M 2 pools. In total, 14 and 13 mutated genes, including bin2, egy1, gl1, gl2, hy1, hy3–5, ttg1, and var2, were identified in the plants derived from Ar- and C-ions irradiation, respectively. In the mutants from both irradiations, deletion was the most frequent type of mutation; 13 of the 14 mutated genes from the Ar ion-irradiated plants and 11 of the 13 mutated genes from the C ion-irradiated plants harbored deletions. Analysis of junction regions generated by the 2 types of irradiation suggested that alternative non-homologous end-joining was the predominant pathway of repair of break points. Among the deletions, the proportion of large deletions (>100 bp) was about 54% for Ar-ion irradiation and about 64% for C-ion irradiation. Both current results and previously reported data revealed that the proportions of the large deletions induced by 290-keV μm −1 radiations were higher than those of the large deletions induced by lower-LET radiations (6% for 22.5–30.0 keV μm −1 and 27% for 101–124 keV μm −1 ). Therefore, the 290 keV μm −1 heavy-ion beams can effectively induce large deletions and will prove useful as novel mutagens for plant breeding and analysis of gene functions, particularly tandemly arrayed genes.

Molecular nature of mutations induced by high-LET irradiation with argon and carbon ions in Arabidopsis thaliana

Energy Technology Data Exchange (ETDEWEB)

Hirano, Tomonari; Kazama, Yusuke [Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Innovation Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Ohbu, Sumie; Shirakawa, Yuki; Liu Yang; Kambara, Tadashi; Fukunishi, Nobuhisa [Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Abe, Tomoko, E-mail: tomoabe@riken.jp [Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Innovation Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

2012-07-01

Linear energy transfer (LET) is an important parameter to be considered in heavy-ion mutagenesis. However, in plants, no quantitative data are available on the molecular nature of the mutations induced with high-LET radiation above 101-124 keV {mu}m{sup -1}. In this study, we irradiated dry seeds of Arabidopsis thaliana with Ar and C ions with an LET of 290 keV {mu}m{sup -1}. We analyzed the DNA alterations caused by the higher-LET radiation. Mutants were identified from the M{sub 2} pools. In total, 14 and 13 mutated genes, including bin2, egy1, gl1, gl2, hy1, hy3-5, ttg1, and var2, were identified in the plants derived from Ar- and C-ions irradiation, respectively. In the mutants from both irradiations, deletion was the most frequent type of mutation; 13 of the 14 mutated genes from the Ar ion-irradiated plants and 11 of the 13 mutated genes from the C ion-irradiated plants harbored deletions. Analysis of junction regions generated by the 2 types of irradiation suggested that alternative non-homologous end-joining was the predominant pathway of repair of break points. Among the deletions, the proportion of large deletions (>100 bp) was about 54% for Ar-ion irradiation and about 64% for C-ion irradiation. Both current results and previously reported data revealed that the proportions of the large deletions induced by 290-keV {mu}m{sup -1} radiations were higher than those of the large deletions induced by lower-LET radiations (6% for 22.5-30.0 keV {mu}m{sup -1} and 27% for 101-124 keV {mu}m{sup -1}). Therefore, the 290 keV {mu}m{sup -1} heavy-ion beams can effectively induce large deletions and will prove useful as novel mutagens for plant breeding and analysis of gene functions, particularly tandemly arrayed genes.

Hypertrophic cardiomyopathy-linked mutation in troponin T causes myofibrillar disarray and pro-arrhythmic action potential changes in human iPSC cardiomyocytes.

Science.gov (United States)

Wang, Lili; Kim, Kyungsoo; Parikh, Shan; Cadar, Adrian Gabriel; Bersell, Kevin R; He, Huan; Pinto, Jose R; Kryshtal, Dmytro O; Knollmann, Bjorn C

2018-01-01

Mutations in cardiac troponin T (TnT) are linked to increased risk of ventricular arrhythmia and sudden death despite causing little to no cardiac hypertrophy. Studies in mice suggest that the hypertrophic cardiomyopathy (HCM)-associated TnT-I79N mutation increases myofilament Ca sensitivity and is arrhythmogenic, but whether findings from mice translate to human cardiomyocyte electrophysiology is not known. To study the effects of the TnT-I79N mutation in human cardiomyocytes. Using CRISPR/Cas9, the TnT-I79N mutation was introduced into human induced pluripotent stem cells (hiPSCs). We then used the matrigel mattress method to generate single rod-shaped cardiomyocytes (CMs) and studied contractility, Ca handling and electrophysiology. Compared to isogenic control hiPSC-CMs, TnT-I79N hiPSC-CMs exhibited sarcomere disorganization, increased systolic function and impaired relaxation. The Ca-dependence of contractility was leftward shifted in mutation containing cardiomyocytes, demonstrating increased myofilament Ca sensitivity. In voltage-clamped hiPSC-CMs, TnT-I79N reduced intracellular Ca transients by enhancing cytosolic Ca buffering. These changes in Ca handling resulted in beat-to-beat instability and triangulation of the cardiac action potential, which are predictors of arrhythmia risk. The myofilament Ca sensitizer EMD57033 produced similar action potential triangulation in control hiPSC-CMs. The TnT-I79N hiPSC-CM model not only reproduces key cellular features of TnT-linked HCM such as myofilament disarray, hypercontractility and diastolic dysfunction, but also suggests that this TnT mutation causes pro-arrhythmic changes of the human ventricular action potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic improvement of black gram using induced mutations

International Nuclear Information System (INIS)

Pawar, S.E.; Manjaya, J.G.; Souframanien, J.; Bhatkar, S.M.

2000-01-01

Induced mutagenesis is an important tool for creating genetic variability in crop plants and has played a significant role in the development of many crop varieties. Genetic improvement of black gram (Vigna mungo L. Hepper) through induced mutations has been in progress at BARC for the past three decades. Mutation studies of genotype EC-168200 have resulted in isolating large number of mutants with distinct morphological characters. TAU-5, an early maturing mutant was identified as a resistant donor for yellow mosaic virus (YMV) disease by the All India Pulse Improvement Project, ICAR, Kanpur. TAU-5 was used in cross breeding with elite cultivars like T-9, TPU-4 and LBG-17. Twelve selections with high yield potential suitable for both kharif and rabi cultivation have been developed. One of the selections TU94-2 has been released for commercial cultivation for southern zone during 1999. The work on the development of YMV resistant genotypes is in progress and will be discussed. (author)

Predicting the impact of Lynch syndrome-causing missense mutations from structural calculations

DEFF Research Database (Denmark)

Nielsen, Sofie V,; Stein, Amelie; Dinitzen, Alexander B.

2017-01-01

selected the human mismatch repair protein, MSH2, where missense variants are known to cause the hereditary cancer predisposition disease, known as Lynch syndrome. We show that the majority of disease-causing MSH2 mutations give rise to folding defects and proteasome-dependent degradation rather than...... and for diagnosis of Lynch syndrome, and perhaps other hereditary diseases....

Research highlights on: the use of induced mutations for plant improvement in Malaysia

International Nuclear Information System (INIS)

1998-01-01

Nuclear techniques play an increasingly valuable role in agricultural research and development. The collaborative work of IAEA and FAO has been instrumental to the progress. The nuclear techniques are now used in a wide range of applications including crop improvement. In the initial years, many plant breeders had difficulty in believing that induced mutations through radiation had any relevance to their conventional procedures. But attitudes have greatly changed, in great part due to the Joint Division's programmes. The result was a high number of improved new varieties bred to date with the help of induced mutations, including some in this country. This publication is intended primarily to gather and put in order all information on the research and work on the use of induced mutations for plant breeding in the country. Its main purpose is to see if ensuing research efforts could be better coordinated, focused and enhanced in order to supplement the plant improvement programmes in the country. The task of collating the relevant information was not without difficulty since many of the work had been carried out long time ago; their objectives generally were quite broad; and the results essentially not published, with some exceptions. Section I begins with thefntroduction, giving a brief account of the developments of induced mutations in Malaysia, the facilities available in various institutions and the role played by the National Committee on the Use of Mutations in Plant Breeding. The collaborative efforts of IAEA and IFNCC are also briefly described here, together with all the activates which they had supported in the past. Section 11 briefly describes the induced mutations and how they are produced and utilised in the plant improvement programmes, taking into consideration the safety precautions required, and the requirements of different crop species. Section III describes in greater details all the research that had been carried out in the country. The

Generation and analysis of knock-in mice carrying pseudohypoaldosteronism type II-causing mutations in the cullin 3 gene.

Science.gov (United States)

Araki, Yuya; Rai, Tatemitsu; Sohara, Eisei; Mori, Takayasu; Inoue, Yuichi; Isobe, Kiyoshi; Kikuchi, Eriko; Ohta, Akihito; Sasaki, Sei; Uchida, Shinichi

2015-10-21

Pseudohypoaldosteronism type II (PHAII) is a hereditary hypertensive disease caused by mutations in four different genes: with-no-lysine kinases (WNK) 1 and 4, Kelch-like family member 3 (KLHL3), and cullin 3 (Cul3). Cul3 and KLHL3 form an E3 ligase complex that ubiquitinates and reduces the expression level of WNK4. PHAII-causing mutations in WNK4 and KLHL3 impair WNK4 ubiquitination. However, the molecular pathogenesis of PHAII caused by Cul3 mutations is unclear. In cultured cells and human leukocytes, PHAII-causing Cul3 mutations result in the skipping of exon 9, producing mutant Cul3 protein lacking 57 amino acids. However, whether this phenomenon occurs in the kidneys and is responsible for the pathogenesis of PHAII in vivo is unknown. We generated knock-in mice carrying a mutation in the C-terminus of intron 8 of Cul3, c.1207-1G>A, which corresponds to a PHAII-causing mutation in the human Cul3 gene. Heterozygous Cul3(G(-1)A/+) knock-in mice did not exhibit PHAII phenotypes, and the skipping of exon 9 was not evident in their kidneys. However, the level of Cul3 mRNA expression in the kidneys of heterozygous knock-in mice was approximately half that of wild-type mice. Furthermore, homozygous knock-in mice were nonviable. It suggested that the mutant allele behaved like a knockout allele and did not produce Cul3 mRNA lacking exon 9. A reduction in Cul3 expression alone was not sufficient to develop PHAII in the knock-in mice. Our findings highlighted the pathogenic role of mutant Cul3 protein and provided insight to explain why PHAII-causing mutations in Cul3 cause kidney-predominant PHAII phenotypes. © 2015. Published by The Company of Biologists Ltd.

L-3-n-Butylphthalide Protects HSPB8 K141N Mutation-Induced Oxidative Stress by Modulating the Mitochondrial Apoptotic and Nrf2 Pathways

Directory of Open Access Journals (Sweden)

Xiao-Dong Yang

2017-07-01

Full Text Available Charcot–Marie–Tooth disease (CMT, also known as hereditary motor and sensory neuropathy, is the most common inherited peripheral nerve disorder. Missense mutations, such as K141N, in the small heat shock protein HSPB8 are known to cause distal hereditary motor neuropathy 2A (dHMN2A or Charcot-Marie-Tooth neuropathy type 2L (CMT2L. However, of critical clinical significance, very few specific therapies for this disease exist. In the present study, we investigated the impact of mutant K141N HSPB8 on mitochondrial distribution and function in a cellular model of CMT2L. Our results indicate that K141N HSPB8 induced mitochondrial aggregation and caused increased oxidative stress injury. As an extraction from Chinese celery Apium graveolens Linn seeds, L-3-n-Butylphthalide (NBP, has been reported to exert many neuroprotective effects, we interrogated whether NBP could elicit a protective effect on the cell injury typically caused by HSPB8 K141N mutations. We found NBP could reverse the pathological processes induced by HSPB8 K141N mutation via an antioxidant effect, modulation of the Bax/Bcl-2 mitochondrial apoptotic and Nrf2 pathways. We propose a novel function of HSPB8, highlighting the consequence of the K141N pathogenic mutation. Furthermore, we suggest NBP may have promising therapeutic potential in the treatment of CMT2L.

Contractile Defect Caused by Mutation in MYBPC3 Revealed under Conditions Optimized for Human PSC-Cardiomyocyte Function

Directory of Open Access Journals (Sweden)

Matthew J. Birket

2015-10-01

Full Text Available Maximizing baseline function of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs is essential for their effective application in models of cardiac toxicity and disease. Here, we aimed to identify factors that would promote an adequate level of function to permit robust single-cell contractility measurements in a human induced pluripotent stem cell (hiPSC model of hypertrophic cardiomyopathy (HCM. A simple screen revealed the collaborative effects of thyroid hormone, IGF-1 and the glucocorticoid analog dexamethasone on the electrophysiology, bioenergetics, and contractile force generation of hPSC-CMs. In this optimized condition, hiPSC-CMs with mutations in MYBPC3, a gene encoding myosin-binding protein C, which, when mutated, causes HCM, showed significantly lower contractile force generation than controls. This was recapitulated by direct knockdown of MYBPC3 in control hPSC-CMs, supporting a mechanism of haploinsufficiency. Modeling this disease in vitro using human cells is an important step toward identifying therapeutic interventions for HCM.

Radiation induced mutations in Phaseolus vulgaris L

International Nuclear Information System (INIS)

Al-Rubeai, M.A.F.

1982-01-01

A selection of various macro- and micro-mutations was undertaken in the M2 generation of Phaseolus vulgaris cultivars after seed exposure to acute gamma radiation doses of 2.5, 5, 7, 10 and 15 Kr. The chlorophyll mutation was positively correlated with dose. Nevertheless, the highest frequency was at 7 Kr. Several interesting morphological mutants were observed. There were dwarf, stiff stem, shiny small leaf, narrow leaf and green giant mutants. Two selected micromutants were superior in seed yield capacity to their parents. The high yields were related to the high number of pods per plant. In 'The Prince' (seed color: red with beige marbling) several mutants with seeds of black color marbled with beige were selected. These seeds gave M3 segregants exhibiting a range of seed colors including white. Many of these M3 plants were short, early flowering and highly sterile. The work demonstrated that the pigmentation character can readily be changed, and confirmed that the variability induced by radiation can be exploited to obtain desirable mutations. (Author) [pt

Deletion mutations of bacteriophage

International Nuclear Information System (INIS)

Ryo, Yeikou

1975-01-01

Resolution of mutation mechanism with structural changes of DNA was discussed through the studies using bacteriophage lambda. One of deletion mutations inductions of phage lambda is the irradiation of ultraviolet ray. It is not clear if the inductions are caused by errors in reparation of ultraviolet-induced damage or by the activation of int gene. Because the effective site of int gene lies within the regions unnecessary for existing, it is considered that int gene is connected to deletion mutations induction. A certain system using prophage complementarity enables to detect deletion mutations at essential hereditary sites and to solve the relations of deletion mutations with other recombination system, DNA reproduction and repairment system. Duplication and multiplication of hereditary elements were discussed. If lambda deletion mutations of the system, which can control recombination, reproduction and repairment of added DNA, are constructed, mutations mechanism with great changes of DNA structure can be solved by phage lambda. (Ichikawa, K.)

Cytosine arabinoside enhancement of gamma irradiation induced mutations in human T-lymphocytes

International Nuclear Information System (INIS)

O'Neill, J.P.; Sullivan, L.M.; Hunter, T.C.; Nicklas, J.A.

1991-01-01

The frequency of 6-thioguanine resistant (TGr) mutants induced in human G0 phase T-lymphocytes by 200 cGy of gamma irradiation is greatly enhanced by incubation with cytosine arabinoside (ara-C) after irradiation. The mutant frequency increased with increasing incubation time in ara-C for up to 2 hr. This mutation induction required a phenotypic expression time of 5-8 days mass culture growth, similar to that found with mutants induced by 300 cGy of irradiation alone. Southern blot analysis of 40 isolated mutant clones revealed 8 independent mutations by T-cell receptor (TCR) gene rearrangement patterns. Four of these eight showed hprt gene structural alterations (0.50). An alternative method to allow phenotypic expression was developed to minimize the isolation of hprt/TCR sibling mutants. The use of in situ expression in the microtiter dish wells resulted in the isolation of 17 independent mutations in 19 mutant clones. Ten of these 17 mutations showed hprt structural alterations (0.59). The high fraction of mutations involving structural alterations detected by Southern blot analysis is consistent with the known induction of chromosome aberrations by irradiation plus ara-C treatment. We propose that both the increase in Mf and the increase in the incidence of hprt gene structural alterations are due to the accumulation of strand breaks in repairing regions of DNA under these conditions of ara-C induced inhibition of repair. We further propose that upon release of the ara-C inhibition, these repairing regions can interact to yield both gene mutations and chromosome aberrations

Cellular repair and its importance for UV-induced mutations

Energy Technology Data Exchange (ETDEWEB)

Slamenova, D [Slovenska Akademia Vied, Bratislava (Czechoslovakia). Vyskumny Ustav Onkologicky

1975-01-01

Current knowledge is briefly surveyed of the mechanism of the biological repair of injuries induced in DNA cells by the action of various factors, mainly ultraviolet radiation. Genetic loci determining the sensitivity of cells to UV radiation are defined and principal reparation processes are explained; excision repair is described more fully. The role of biological repair is discussed in view of UV-induced mutations in DNA cells.

Site-specific analysis of UV-induced cyclobutane pyrimidine dimers in nucleotide excision repair-proficient and -deficient hamster cells: Lack of correlation with mutational spectra

International Nuclear Information System (INIS)

Vreeswijk, Maaike P.G.; Meijers, Caro M.; Giphart-Gassler, Micheline; Vrieling, Harry; Zeeland, Albert A. van; Mullenders, Leon H.F.; Loenen, Wil A.M.

2009-01-01

Irradiation of cells with UVC light induces two types of mutagenic DNA photoproducts, i.e. cyclobutane pyrimidine dimers (CPD) and pyrimidine (6-4) pyrimidone photoproducts (6-4PP). To investigate the relationship between the frequency of UV-induced photolesions at specific sites and their ability to induce mutations, we quantified CPD formation at the nucleotide level along exons 3 and 8 of the hprt gene using ligation-mediated PCR, and determined the mutational spectrum of 132 UV-induced hprt mutants in the AA8 hamster cell line and of 165 mutants in its nucleotide excision repair-defective derivative UV5. In AA8 cells, transversions predominated with a strong strand bias towards thymine-containing photolesions in the non-transcribed strand. As hamster AA8 cells are proficient in global genome repair of 6-4PP but selectively repair CPD from the transcribed strand of active genes, most mutations probably resulted from erroneous bypass of CPD in the non-transcribed strand. However, the relative incidence of CPD and the positions where mutations most frequently arose do not correlate. In fact some major damage sites hardly gave rise to the formation of mutations. In the repair-defective UV5 cells, mutations were almost exclusively C > T transitions caused by photoproducts at PyC sites in the transcribed strand. Even though CPD were formed at high frequencies at some TT sites in UV5, these photoproducts did not contribute to mutation induction at all. We conclude that, even in the absence of repair, large variations in the level of induction of CPD at different sites throughout the two exons do not correspond to frequencies of mutation induction.

Effect of ethyl-, methyl- and hydroxyethyl-nitrosourea on the mouse testis

Energy Technology Data Exchange (ETDEWEB)

Oakberg, E.F.; Crosthwait, C.D.

1983-01-01

Hybrid male 101 x C3HF/sub 1/ mice were given intraperitoneal injections of methyl-, ethyl- and hydroxyethyl-nitrosourea and killed 3-16 days later. All compounds were similar in that all differentiating spermatogonia from type A/sub 1/ to early type B were killed by 50 mg/kg and higher doses of ENU and by 75 mg/kg MNU. Cells exposed to leptotene to 100 and 250 mg/kg ENU and 455 mg/kg HENU showed a delayed response with degeneration in pachytene 5 days later. Labeling prior to exposure to ENU indicated that the effect of stage of the mitotic cycle on sensitivity to cell killing is less marked than for radiation. This may be the explanation for the s-shaped mutation induction curve obtained with ENU in contrast to the humped dose-response curve observed for radiation.

Base substitutions, frameshifts, and small deletions constitute ionizing radiation-induced point mutations in mammalian cells

International Nuclear Information System (INIS)

Grosovsky, A.J.; de Boer, J.G.; de Jong, P.J.; Drobetsky, E.A.; Glickman, B.W.

1988-01-01

The relative role of point mutations and large genomic rearrangements in ionizing radiation-induced mutagenesis has been an issue of long-standing interest. Recent studies using Southern blotting analysis permit the partitioning of ionizing radiation-induced mutagenesis in mammalian cells into detectable deletions and major genomic rearrangements and into point mutations. The molecular nature of these point mutations has been left unresolved; they may include base substitutions as well as small deletions, insertions, and frame-shifts below the level of resolution of Southern blotting analysis. In this investigation, we have characterized a collection of ionizing radiation-induced point mutations at the endogenous adenine phosphoribosyltransferase (aprt) locus of Chinese hamster ovary cells at the DNA sequence level. Base substitutions represented approximately equal to 2/3 of the point mutations analyzed. Although the collection of mutants is relatively small, every possible type of base substitution event has been recovered. These mutations are well distributed throughout the coding sequence with only one multiple occurrence. Small deletions represented the remainder of characterized mutants; no insertions have been observed. Sequence-directed mechanisms mediated by direct repeats could account for some of the observed deletions, while others appear to be directly attributable to radiation-induced strand breakage

A frame-shift mutation of PMS2 is a widespread cause of Lynch syndrome.

Science.gov (United States)

Clendenning, M; Senter, L; Hampel, H; Robinson, K Lagerstedt; Sun, S; Buchanan, D; Walsh, M D; Nilbert, M; Green, J; Potter, J; Lindblom, A; de la Chapelle, A

2008-06-01

When compared to the other mismatch repair genes involved in Lynch syndrome, the identification of mutations within PMS2 has been limited (PMS2. This disparity is primarily due to complications in the study of this gene caused by interference from pseudogene sequences. Using a recently developed method for detecting PMS2 specific mutations, we have screened 99 patients who are likely candidates for PMS2 mutations based on immunohistochemical analysis. We have identified a frequently occurring frame-shift mutation (c.736_741del6ins11) in 12 ostensibly unrelated Lynch syndrome patients (20% of patients we have identified with a deleterious mutation in PMS2, n = 61). These individuals all display the rare allele (population frequency 10 000 carriers of this mutation in the USA alone. The identification of both the mutation and the common haplotype in one Swedish control sample (n = 225), along with evidence that Lynch syndrome associated cancers are rarer than expected in the probands' families, would suggest that this is a prevalent mutation with reduced penetrance.

Induced mutations for improvement of grain legume production II

International Nuclear Information System (INIS)

1982-02-01

Out of 18 papers presented, 15 fall within the INIS subject scope. Other topics covered were: mutagenic efficiency of ethylmethane sulphonate in soybean; induced mutations for rust resistance in soybean; and nitrogen fixation-potentials for improvement in legumes

Induced mutations of rust resistance genes in wheat

International Nuclear Information System (INIS)

McIntosh, R.A.

1983-01-01

Induced mutations are being used as a tool to study genes for resistance in wheat. It was found that Pm1 can be separated from Lr20 and Sr15, but these two react like a single pleiotropic gene. Mutants were further examined in crosses and backmutations have been attempted. (author)

Mutations in KPTN Cause Macrocephaly, Neurodevelopmental Delay, and Seizures

Science.gov (United States)

Baple, Emma L.; Maroofian, Reza; Chioza, Barry A.; Izadi, Maryam; Cross, Harold E.; Al-Turki, Saeed; Barwick, Katy; Skrzypiec, Anna; Pawlak, Robert; Wagner, Karin; Coblentz, Roselyn; Zainy, Tala; Patton, Michael A.; Mansour, Sahar; Rich, Phillip; Qualmann, Britta; Hurles, Matt E.; Kessels, Michael M.; Crosby, Andrew H.

2014-01-01

The proper development of neuronal circuits during neuromorphogenesis and neuronal-network formation is critically dependent on a coordinated and intricate series of molecular and cellular cues and responses. Although the cortical actin cytoskeleton is known to play a key role in neuromorphogenesis, relatively little is known about the specific molecules important for this process. Using linkage analysis and whole-exome sequencing on samples from families from the Amish community of Ohio, we have demonstrated that mutations in KPTN, encoding kaptin, cause a syndrome typified by macrocephaly, neurodevelopmental delay, and seizures. Our immunofluorescence analyses in primary neuronal cell cultures showed that endogenous and GFP-tagged kaptin associates with dynamic actin cytoskeletal structures and that this association is lost upon introduction of the identified mutations. Taken together, our studies have identified kaptin alterations responsible for macrocephaly and neurodevelopmental delay and define kaptin as a molecule crucial for normal human neuromorphogenesis. PMID:24239382

Intercellular distribution of mutations induced in oopcytes of Drosophila melanogaster by chemical and physical mutagens

International Nuclear Information System (INIS)

Traut, H.

1979-01-01

When females of Drosophila melanogaster are treated with chemical or physical mutagens, not only in one but also in both of the two homologous X chromosomes of a given oocyte, a recessive sex-linked lethal mutation may be induced. A method is described that discriminates between such single and double mutations. A theory is developed to show how a comparison betweeen the expected and the observer frequency of double mutations yields an indication of the intercellular distribution (random or nonrandom) of recessive lethal mutations induced by mutagenic agents in oocytes and, consequently, of the distribution (homogenous or nonhomogeneous) of those agents. Three agents were tested: FUdR (12.5, 50.0 and 81.0 μg/ml), mitomycin C (130.0 μg/ml) and x rays (2000 R, 150 kV). After FUdR feeding, no increase in the mutation frequency usually observed in D. melanogaster without mutagenic treatment was obtained (u = 0.13%, namely three single mutations among 2332 chromosomes tested). After mitomycin C feeding 104 single and three double mutations were obtained. All of the 50 mutations observed after x irradiation were single mutations. The results obtained in the mitomycin C and radiation experiments favor the assumption of a random intercellular distribution of recessive lethal mutations induced by these two agents in oocytes of D. melanogaster. Reasons are discussed why for other types of mutagenic agents nonrandom distributions may be observed with our technique

Recessive Mutations in ACPT, Encoding Testicular Acid Phosphatase, Cause Hypoplastic Amelogenesis Imperfecta.

Science.gov (United States)

Seymen, Figen; Kim, Youn Jung; Lee, Ye Ji; Kang, Jenny; Kim, Tak-Heun; Choi, Hwajung; Koruyucu, Mine; Kasimoglu, Yelda; Tuna, Elif Bahar; Gencay, Koray; Shin, Teo Jeon; Hyun, Hong-Keun; Kim, Young-Jae; Lee, Sang-Hoon; Lee, Zang Hee; Zhang, Hong; Hu, Jan C-C; Simmer, James P; Cho, Eui-Sic; Kim, Jung-Wook

2016-11-03

Amelogenesis imperfecta (AI) is a heterogeneous group of genetic disorders affecting tooth enamel. The affected enamel can be hypoplastic and/or hypomineralized. In this study, we identified ACPT (testicular acid phosphatase) biallelic mutations causing non-syndromic, generalized hypoplastic autosomal-recessive amelogenesis imperfecta (AI) in individuals from six apparently unrelated Turkish families. Families 1, 4, and 5 were affected by the homozygous ACPT mutation c.713C>T (p.Ser238Leu), family 2 by the homozygous ACPT mutation c.331C>T (p.Arg111Cys), family 3 by the homozygous ACPT mutation c.226C>T (p.Arg76Cys), and family 6 by the compound heterozygous ACPT mutations c.382G>C (p.Ala128Pro) and 397G>A (p.Glu133Lys). Analysis of the ACPT crystal structure suggests that these mutations damaged the activity of ACPT by altering the sizes and charges of key amino acid side chains, limiting accessibility of the catalytic core, and interfering with homodimerization. Immunohistochemical analysis confirmed localization of ACPT in secretory-stage ameloblasts. The study results provide evidence for the crucial function of ACPT during amelogenesis. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Mutations in CDK5RAP2 cause Seckel syndrome.

Science.gov (United States)

Yigit, Gökhan; Brown, Karen E; Kayserili, Hülya; Pohl, Esther; Caliebe, Almuth; Zahnleiter, Diana; Rosser, Elisabeth; Bögershausen, Nina; Uyguner, Zehra Oya; Altunoglu, Umut; Nürnberg, Gudrun; Nürnberg, Peter; Rauch, Anita; Li, Yun; Thiel, Christian Thomas; Wollnik, Bernd

2015-09-01

Seckel syndrome is a heterogeneous, autosomal recessive disorder marked by prenatal proportionate short stature, severe microcephaly, intellectual disability, and characteristic facial features. Here, we describe the novel homozygous splice-site mutations c.383+1G>C and c.4005-9A>G in CDK5RAP2 in two consanguineous families with Seckel syndrome. CDK5RAP2 (CEP215) encodes a centrosomal protein which is known to be essential for centrosomal cohesion and proper spindle formation and has been shown to be causally involved in autosomal recessive primary microcephaly. We establish CDK5RAP2 as a disease-causing gene for Seckel syndrome and show that loss of functional CDK5RAP2 leads to severe defects in mitosis and spindle organization, resulting in cells with abnormal nuclei and centrosomal pattern, which underlines the important role of centrosomal and mitotic proteins in the pathogenesis of the disease. Additionally, we present an intriguing case of possible digenic inheritance in Seckel syndrome: A severely affected child of nonconsanguineous German parents was found to carry heterozygous mutations in CDK5RAP2 and CEP152. This finding points toward a potential additive genetic effect of mutations in CDK5RAP2 and CEP152.

Mutations in CDK5RAP2 cause Seckel syndrome

Science.gov (United States)

Yigit, Gökhan; Brown, Karen E; Kayserili, Hülya; Pohl, Esther; Caliebe, Almuth; Zahnleiter, Diana; Rosser, Elisabeth; Bögershausen, Nina; Uyguner, Zehra Oya; Altunoglu, Umut; Nürnberg, Gudrun; Nürnberg, Peter; Rauch, Anita; Li, Yun; Thiel, Christian Thomas; Wollnik, Bernd

2015-01-01

Seckel syndrome is a heterogeneous, autosomal recessive disorder marked by prenatal proportionate short stature, severe microcephaly, intellectual disability, and characteristic facial features. Here, we describe the novel homozygous splice-site mutations c.383+1G>C and c.4005-9A>G in CDK5RAP2 in two consanguineous families with Seckel syndrome. CDK5RAP2 (CEP215) encodes a centrosomal protein which is known to be essential for centrosomal cohesion and proper spindle formation and has been shown to be causally involved in autosomal recessive primary microcephaly. We establish CDK5RAP2 as a disease-causing gene for Seckel syndrome and show that loss of functional CDK5RAP2 leads to severe defects in mitosis and spindle organization, resulting in cells with abnormal nuclei and centrosomal pattern, which underlines the important role of centrosomal and mitotic proteins in the pathogenesis of the disease. Additionally, we present an intriguing case of possible digenic inheritance in Seckel syndrome: A severely affected child of nonconsanguineous German parents was found to carry heterozygous mutations in CDK5RAP2 and CEP152. This finding points toward a potential additive genetic effect of mutations in CDK5RAP2 and CEP152. PMID:26436113

Heavy ion induced mutation in arabidopsis

Energy Technology Data Exchange (ETDEWEB)

Tano, Shigemitsu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1997-03-01

Heavy ions, He, C, Ar and Ne were irradiated to the seeds of Arabidopsis thaliana for inducing the new mutants. In the irradiated generation (M{sub 1}), germination and survival rate were observed to estimate the relative biological effectiveness in relation to the LET including the inactivation cross section. Mutation frequencies were compared by using three kinds of genetic loci after irradiation with C ions and electrons. Several interesting new mutants were selected in the selfed progenies of heavy ion irradiated seeds. (author)

Mutations in ALDH1A3 represent a frequent cause of microphthalmia/anophthalmia in consanguineous families.

Science.gov (United States)

Abouzeid, Hana; Favez, Tatiana; Schmid, Angélique; Agosti, Céline; Youssef, Mohammed; Marzouk, Iman; El Shakankiry, Nihal; Bayoumi, Nader; Munier, Francis L; Schorderet, Daniel F

2014-08-01

Anophthalmia or microphthalmia (A/M), characterized by absent or small eye, can be unilateral or bilateral and represent developmental anomalies due to the mutations in several genes. Recently, mutations in aldehyde dehydrogenase family 1, member A3 (ALDH1A3) also known as retinaldehyde dehydrogenase 3, have been reported to cause A/M. Here, we screened a cohort of 75 patients with A/M and showed that mutations in ALDH1A3 occurred in six families. Based on this series, we estimate that mutations in ALDH1A3 represent a major cause of A/M in consanguineous families, and may be responsible for approximately 10% of the cases. Screening of this gene should be performed in a first line of investigation, together with SOX2. © 2014 WILEY PERIODICALS, INC.

Gain-of-function SOS1 mutations cause a distinctive form of noonansyndrome

Energy Technology Data Exchange (ETDEWEB)

Tartaglia, Marco; Pennacchio, Len A.; Zhao, Chen; Yadav, KamleshK.; Fodale, Valentina; Sarkozy, Anna; Pandit, Bhaswati; Oishi, Kimihiko; Martinelli, Simone; Schackwitz, Wendy; Ustaszewska, Anna; Martin, Joes; Bristow, James; Carta, Claudio; Lepri, Francesca; Neri, Cinzia; Vasta,Isabella; Gibson, Kate; Curry, Cynthia J.; Lopez Siguero, Juan Pedro; Digilio, Maria Cristina; Zampino, Giuseppe; Dallapiccola, Bruno; Bar-Sagi, Dafna; Gelb, Brude D.

2006-09-01

Noonan syndrome (NS) is a developmental disordercharacterized by short stature, facial dysmorphia, congenital heartdefects and skeletal anomalies1. Increased RAS-mitogenactivated proteinkinase (MAPK) signaling due to PTPN11 and KRAS mutations cause 50 percentof NS2-6. Here, we report that 22 of 129 NS patients without PTPN11 orKRAS mutation (17 percent) have missense mutations in SOS1, which encodesa RAS-specific guanine nucleotide exchange factor (GEF). SOS1 mutationscluster at residues implicated in the maintenance of SOS1 in itsautoinhibited form and ectopic expression of two NS-associated mutantsinduced enhanced RAS activation. The phenotype associated with SOS1defects is distinctive, although within NS spectrum, with a highprevalence of ectodermal abnormalities but generally normal developmentand linear growth. Our findings implicate for the first timegain-of-function mutations in a RAS GEF in inherited disease and define anew mechanism by which upregulation of the RAS pathway can profoundlychange human development.

Mutations in the ABCA4 (ABCR) gene are the major cause of autosomal recessive cone-rod dystrophy.

Science.gov (United States)

Maugeri, A; Klevering, B J; Rohrschneider, K; Blankenagel, A; Brunner, H G; Deutman, A F; Hoyng, C B; Cremers, F P

2000-10-01

The photoreceptor cell-specific ATP-binding cassette transporter gene (ABCA4; previously denoted "ABCR") is mutated, in most patients, with autosomal recessive (AR) Stargardt disease (STGD1) or fundus flavimaculatus (FFM). In addition, a few cases with AR retinitis pigmentosa (RP) and AR cone-rod dystrophy (CRD) have been found to have ABCA4 mutations. To evaluate the importance of the ABCA4 gene as a cause of AR CRD, we selected 5 patients with AR CRD and 15 patients from Germany and The Netherlands with isolated CRD. Single-strand conformation-polymorphism analysis and sequencing revealed 19 ABCA4 mutations in 13 (65%) of 20 patients. In six patients, mutations were identified in both ABCA4 alleles; in seven patients, mutations were detected in one allele. One complex ABCA4 allele (L541P;A1038V) was found exclusively in German patients with CRD; one patient carried this complex allele homozygously, and five others were compound heterozygous. These findings suggest that mutations in the ABCA4 gene are the major cause of AR CRD. A primary role of the ABCA4 gene in STGD1/FFM and AR CRD, together with the gene's involvement in an as-yet-unknown proportion of cases with AR RP, strengthens the idea that mutations in the ABCA4 gene could be the most frequent cause of inherited retinal dystrophy in humans.

ITGB6 loss-of-function mutations cause autosomal recessive amelogenesis imperfecta.

Science.gov (United States)

Wang, Shih-Kai; Choi, Murim; Richardson, Amelia S; Reid, Bryan M; Lin, Brent P; Wang, Susan J; Kim, Jung-Wook; Simmer, James P; Hu, Jan C-C

2014-04-15

Integrins are cell-surface adhesion receptors that bind to extracellular matrices (ECM) and mediate cell-ECM interactions. Some integrins are known to play critical roles in dental enamel formation. We recruited two Hispanic families with generalized hypoplastic amelogenesis imperfecta (AI). Analysis of whole-exome sequences identified three integrin beta 6 (ITGB6) mutations responsible for their enamel malformations. The female proband of Family 1 was a compound heterozygote with an ITGB6 transition mutation in Exon 4 (g.4545G > A c.427G > A p.Ala143Thr) and an ITGB6 transversion mutation in Exon 6 (g.27415T > A c.825T > A p.His275Gln). The male proband of Family 2 was homozygous for an ITGB6 transition mutation in Exon 11 (g.73664C > T c.1846C > T p.Arg616*) and hemizygous for a transition mutation in Exon 6 of Nance-Horan Syndrome (NHS Xp22.13; g.355444T > C c.1697T > C p.Met566Thr). These are the first disease-causing ITGB6 mutations to be reported. Immunohistochemistry of mouse mandibular incisors localized ITGB6 to the distal membrane of differentiating ameloblasts and pre-ameloblasts, and then ITGB6 appeared to be internalized by secretory stage ameloblasts. ITGB6 expression was strongest in the maturation stage and its localization was associated with ameloblast modulation. Our findings demonstrate that early and late amelogenesis depend upon cell-matrix interactions. Our approach (from knockout mouse phenotype to human disease) demonstrates the power of mouse reverse genetics in mutational analysis of human genetic disorders and attests to the need for a careful dental phenotyping in large-scale knockout mouse projects.

Use of ionizing radiation induced mutation in the genetic development of plants

International Nuclear Information System (INIS)

Barragan, Raul; Rubio, Santiago

1993-01-01

The objective of this article is to present a general focus on the use of induced mutations in the improvement of plants. This article describes some basic aspects that must be well known by the breeder that hopes to incorporate in his programm the technique of induced mutation by radiations. In this paper are included the results of two trials done by the researchers of the department of plant breeding so that it can be used as reference to determinate the importance of this technique

A novel nonsense mutation in the WFS1 gene causes the Wolfram syndrome.

Science.gov (United States)

Noorian, Shahab; Savad, Shahram; Mohammadi, Davood Shah

2016-05-01

Wolfram syndrome is a rare autosomal recessive neurodegenerative disorder, which is mostly caused by mutations in the WFS1 gene. The WFS1 gene product, which is called wolframin, is thought to regulate the function of endoplasmic reticulum. The endoplasmic reticulum has a critical role in protein folding and material transportation within the cell or to the surface of the cell. Identification of new mutations in WFS1 gene will unravel the molecular pathology of WS. The aim of this case report study is to describe a novel mutation in exon 4 of the WFS1 gene (c.330C>A) in a 9-year-old boy with WS.

Further evidence that mutations in INS can be a rare cause of Maturity-Onset Diabetes of the Young (MODY)

DEFF Research Database (Denmark)

Boesgaard, Trine W; Pruhova, Stepanka; Andersson, Ehm A

2010-01-01

BACKGROUND: Insulin gene (INS) mutations have recently been described as a common cause of permanent neonatal diabetes (PNDM) and a rare cause of diabetes diagnosed in childhood or adulthood. METHODS: INS was sequenced in 116 maturity-onset diabetes of the young (MODYX) patients (n = 48 Danish an......, and were treated with oral hypoglycaemic agents and/or insulin. CONCLUSION: Mutations in INS can be a rare cause of MODY and we conclude that screening for mutations in INS should be recommended in MODYX patients....

Mutation in filamin A causes periventricular heterotopia, developmental regression, and West syndrome in males.

Science.gov (United States)

Masruha, Marcelo R; Caboclo, Luis O S F; Carrete, Henrique; Cendes, Iscia L; Rodrigues, Murilo G; Garzon, Eliana; Yacubian, Elza M T; Sakamoto, Américo C; Sheen, Volney; Harney, Megan; Neal, Jason; Hill, R Sean; Bodell, Adria; Walsh, Christopher; Vilanova, Luiz C P

2006-01-01

Familial periventricular heterotopia (PH) represents a disorder of neuronal migration resulting in multiple gray-matter nodules along the lateral ventricular walls. Prior studies have shown that mutations in the filamin A (FLNA) gene can cause PH through an X-linked dominant pattern. Heterozygotic female patients usually remain asymptomatic until the second or third decade of life, when they may have predominantly focal seizures, whereas hemizygotic male fetuses typically die in utero. Recent studies have also reported mutations in FLNA in male patients with PH who are cognitively normal. We describe PH in three male siblings with PH due to FLNA, severe developmental regression, and West syndrome. The study includes the three affected brothers and their parents. Video-EEG recordings and magnetic resonance image (MRI) scanning were performed on all individuals. Mutations for FLNA were detected by using polymerase chain reaction (PCR) on genomic DNA followed by single-stranded conformational polymorphism (SSCP) analysis or sequencing. Two of the siblings are monozygotic twins, and all had West syndrome with hypsarrhythmia on EEG. MRI of the brain revealed periventricular nodules of cerebral gray-matter intensity, typical for PH. Mutational analyses demonstrated a cytosine-to-thymidine missense mutation (c. C1286T), resulting in a threonine-to-methionine amino acid substitution in exon 9 of the FLNA gene. The association between PH and West syndrome, to our knowledge, has not been previously reported. Males with PH have been known to harbor FLNA mutations, although uniformly, they either show early lethality or survive and have a normal intellect. The current studies show that FLNA mutations can cause periventricular heterotopia, developmental regression, and West syndrome in male patients, suggesting that this type of FLNA mutation may contribute to severe neurologic deficits.

Protein-truncating mutations in ASPM cause variable reduction in brain size

NARCIS (Netherlands)

Bond, Jacquelyn; Scott, Sheila; Hampshire, Daniel J.; Springell, Kelly; Corry, Peter; Abramowicz, Marc J.; Mochida, Ganesh H.; Hennekam, Raoul C. M.; Maher, Eamonn R.; Fryns, Jean-Pierre; Alswaid, Abdulrahman; Jafri, Hussain; Rashid, Yasmin; Mubaidin, Ammar; Walsh, Christopher A.; Roberts, Emma; Woods, C. Geoffrey

2003-01-01

Mutations in the ASPM gene at the MCPH5 locus are expected to be the most common cause of human autosomal recessive primary microcephaly (MCPH), a condition in which there is a failure of normal fetal brain development, resulting in congenital microcephaly and mental retardation. We have performed

Congenital Hypothyroidism Caused by a PAX8 Gene Mutation Manifested as Sodium/Iodide Symporter Gene Defect

Directory of Open Access Journals (Sweden)

Wakako Jo

2010-01-01

Full Text Available Loss-of-function mutations of the PAX8 gene are considered to mainly cause congenital hypothyroidism (CH due to thyroid hypoplasia. However, some patients with PAX8 mutation have demonstrated a normal-sized thyroid gland. Here we report a CH patient caused by a PAX8 mutation, which manifested as iodide transport defect (ITD. Hypothyroidism was detected by neonatal screening and L-thyroxine replacement was started immediately. Although 123I scintigraphy at 5 years of age showed that the thyroid gland was in the normal position and of small size, his iodide trapping was low. The ratio of the saliva/plasma radioactive iodide was low. He did not have goiter; however laboratory findings suggested that he had partial ITD. Gene analyses showed that the sodium/iodide symporter (NIS gene was normal; instead, a mutation in the PAX8 gene causing R31H substitution was identified. The present report demonstrates that individuals with defective PAX8 can have partial ITD, and thus genetic analysis is useful for differential diagnosis.

Mutator suppression and escape from replication error-induced extinction in yeast.

Directory of Open Access Journals (Sweden)

Alan J Herr

2011-10-01

Full Text Available Cells rely on a network of conserved pathways to govern DNA replication fidelity. Loss of polymerase proofreading or mismatch repair elevates spontaneous mutation and facilitates cellular adaptation. However, double mutants are inviable, suggesting that extreme mutation rates exceed an error threshold. Here we combine alleles that affect DNA polymerase δ (Pol δ proofreading and mismatch repair to define the maximal error rate in haploid yeast and to characterize genetic suppressors of mutator phenotypes. We show that populations tolerate mutation rates 1,000-fold above wild-type levels but collapse when the rate exceeds 10⁻³ inactivating mutations per gene per cell division. Variants that escape this error-induced extinction (eex rapidly emerge from mutator clones. One-third of the escape mutants result from second-site changes in Pol δ that suppress the proofreading-deficient phenotype, while two-thirds are extragenic. The structural locations of the Pol δ changes suggest multiple antimutator mechanisms. Our studies reveal the transient nature of eukaryotic mutators and show that mutator phenotypes are readily suppressed by genetic adaptation. This has implications for the role of mutator phenotypes in cancer.

Mutations in DNMT1 cause autosomal dominant cerebellar ataxia, deafness and narcolepsy

DEFF Research Database (Denmark)

Winkelmann, Juliane; Lin, Ling; Schormair, Barbara

2012-01-01

to HDAC2. It is also highly expressed in immune cells and required for the differentiation of CD4+ into T regulatory cells. Mutations in exon 20 of this gene were recently reported to cause hereditary sensory neuropathy with dementia and hearing loss (HSAN1). Our mutations are all located in exon 21......Autosomal dominant cerebellar ataxia, deafness and narcolepsy (ADCA-DN) is characterized by late onset (30-40 years old) cerebellar ataxia, sensory neuronal deafness, narcolepsy-cataplexy and dementia. We performed exome sequencing in five individuals from three ADCA-DN kindreds and identified DNMT...

Molecular analysis of radiation-induced mutations in vitro

International Nuclear Information System (INIS)

Kronenberg, A.

1996-01-01

This review will focus on the nature of specific locus mutations detected in mammalian cells exposed in vitro to different types of ionizing radiations. Ionizing radiation has been shown to produce a wide variety of heritable alterations in DNA. These range from single base pair substitutions to stable loss or translocation of large portions of whole chromosomes. Data will be reviewed for certain test systems that reveal different mutation spectra. Techniques for the analysis of molecular alterations include applications of the polymerase chain reaction, some of which may be coupled with DNA sequence analysis, and a variety of hybridization-based techniques. The complexity of large scale rearrangements is approached with cytogenetic techniques including high resolution banding and various applications of the fluorescence in situ hybridization (FISH) technique. Radiation-induced mutant frequencies and mutation spectra are a function of the linkage constraints on the recovery of viable mutants for a given locus and test system. 44 refs

Heterozygous Germline Mutations in the CBL Tumor-Suppressor Gene Cause a Noonan Syndrome-like Phenotype

Science.gov (United States)

Martinelli, Simone; De Luca, Alessandro; Stellacci, Emilia; Rossi, Cesare; Checquolo, Saula; Lepri, Francesca; Caputo, Viviana; Silvano, Marianna; Buscherini, Francesco; Consoli, Federica; Ferrara, Grazia; Digilio, Maria C.; Cavaliere, Maria L.; van Hagen, Johanna M.; Zampino, Giuseppe; van der Burgt, Ineke; Ferrero, Giovanni B.; Mazzanti, Laura; Screpanti, Isabella; Yntema, Helger G.; Nillesen, Willy M.; Savarirayan, Ravi; Zenker, Martin; Dallapiccola, Bruno; Gelb, Bruce D.; Tartaglia, Marco

2010-01-01

RAS signaling plays a key role in controlling appropriate cell responses to extracellular stimuli and participates in early and late developmental processes. Although enhanced flow through this pathway has been established as a major contributor to oncogenesis, recent discoveries have revealed that aberrant RAS activation causes a group of clinically related developmental disorders characterized by facial dysmorphism, a wide spectrum of cardiac disease, reduced growth, variable cognitive deficits, ectodermal and musculoskeletal anomalies, and increased risk for certain malignancies. Here, we report that heterozygous germline mutations in CBL, a tumor-suppressor gene that is mutated in myeloid malignancies and encodes a multivalent adaptor protein with E3 ubiquitin ligase activity, can underlie a phenotype with clinical features fitting or partially overlapping Noonan syndrome (NS), the most common condition of this disease family. Independent CBL mutations were identified in two sporadic cases and two families from among 365 unrelated subjects who had NS or suggestive features and were negative for mutations in previously identified disease genes. Phenotypic heterogeneity and variable expressivity were documented. Mutations were missense changes altering evolutionarily conserved residues located in the RING finger domain or the linker connecting this domain to the N-terminal tyrosine kinase binding domain, a known mutational hot spot in myeloid malignancies. Mutations were shown to affect CBL-mediated receptor ubiquitylation and dysregulate signal flow through RAS. These findings document that germline mutations in CBL alter development to cause a clinically variable condition that resembles NS and that possibly predisposes to malignancies. PMID:20619386

Breeding a PKU-mouse model on Phe-free diet, is it possible?

DEFF Research Database (Denmark)

Dagnæs-Hansen, Frederik; Johansen, Karen Singers; Vorup-Jensen, Thomas

2014-01-01

The PKU-mouse model mutated in the PAH gene was developed in the 1990s in the laboratory of Dr. Alexandra Shedlovsky at the McArdle Laboratory for Cancer Research, University of Wisconsin. The mutation was generated by ENU (N-ethyl-N-nitrosourea) treatment of BTBR males. Several mutation was found...

Base substitution spectra of nalidixylate resistant mutations induced by monochromatic soft X and 60Co γ-rays in bacillus subtilis spores

International Nuclear Information System (INIS)

Takahashi, Nobuhiro; Hieda, Kotaro; Morohoshi, Fumiko; Munakata, Nobuo

1999-01-01

Bacillus subtilis spores were exposed to three types of photons, monochromatic soft X-rays with the energy corresponding to the absorption peak of phosphorus K-shell electron (2,153 eV) and with the slightly lower energy (2,147 eV), and 60 Co γ-rays. From the irradiated spores, 233 mutants exhibiting nalidixic acid resistance were isolated, and together with 94 spontaneous mutants, the sequence changes in the 5'-terminal region of the gyrA gene coding for DNA gyrase subunit A were determined. Among eighteen alleles of the gyrA mutations, eight were single-base substitutions, nine were tandem double-base substitutions, and one was a double substitution skipping a middle base pair. About 6% of the radiation-induced mutations were tandem double-base substitutions, whereas none was observed among the spontaneous ones. Among spontaneous mutations, A:T and G:C pairs were equally subjected to mutations, whereas the substitutions from G:C pairs and those to A:T pairs predominated among those induced with soft X-rays. The peak-energy X-rays were more effective in killing and causing mutations than the low-energy X-rays, however, there seemed no base-change events uniquely attributable to phosphorus K-shell absorption. (author)

Mutation induction by ion beams in arabidopsis

International Nuclear Information System (INIS)

Tanaka, Atsushi

1999-01-01

An investigation was made on characteristics of ion beams for the biological effects and the induction of mutation using Arabidopsis plant as a model plant for the molecular genetics. Here, the characteristics of mutation at the molecular level as well as new mutants induced by ion beams were described. The ast and sep1 were obtained from the offspring of 1488 carbon ion-irradiated seeds respectively. The uvi1-uvi4 mutants were also induced from 1280 M 1 lines. Thus, ion beams can induce not only known mutants such as tt, gl and hy but also novel mutants with high frequency. Even in the tt phenotype, two new mutant loci other than known loci were found. In chrysanthemum, several kinds of single, complex or stripped flower-color mutants that have been never induced by γirradiation, indicating that ion beams could produce a variety of mutants with the same phenotype. In conclusion, ion beams for the mutation induction are characterized by 1) to induce mutants with high frequency, 2) to show broad mutation spectrum and 3) to produce novel mutants. For these reasons, chemical mutagens such as EMS and low LET ionizing radiation such as X-rays and γ-rays will predominantly induce many but small modifications or DNA damages on the DNA strands. As the result, several point mutations will be produced on the genome. On the contrary, ion beams as a high LET ionizing radiation will not cause so many but large and irreparable DNA damage locally, resulting in production of limited number of null mutation. (M.N.)

Mutation induction by ion beams in arabidopsis

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Atsushi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1999-07-01

An investigation was made on characteristics of ion beams for the biological effects and the induction of mutation using Arabidopsis plant as a model plant for the molecular genetics. Here, the characteristics of mutation at the molecular level as well as new mutants induced by ion beams were described. The ast and sep1 were obtained from the offspring of 1488 carbon ion-irradiated seeds respectively. The uvi1-uvi4 mutants were also induced from 1280 M{sub 1} lines. Thus, ion beams can induce not only known mutants such as tt, gl and hy but also novel mutants with high frequency. Even in the tt phenotype, two new mutant loci other than known loci were found. In chrysanthemum, several kinds of single, complex or stripped flower-color mutants that have been never induced by {gamma}irradiation, indicating that ion beams could produce a variety of mutants with the same phenotype. In conclusion, ion beams for the mutation induction are characterized by 1) to induce mutants with high frequency, 2) to show broad mutation spectrum and 3) to produce novel mutants. For these reasons, chemical mutagens such as EMS and low LET ionizing radiation such as X-rays and {gamma}-rays will predominantly induce many but small modifications or DNA damages on the DNA strands. As the result, several point mutations will be produced on the genome. On the contrary, ion beams as a high LET ionizing radiation will not cause so many but large and irreparable DNA damage locally, resulting in production of limited number of null mutation. (M.N.)

A rare male patient with classic Rett syndrome caused by MeCP2_e1 mutation.

Science.gov (United States)

Tokaji, Narumi; Ito, Hiromichi; Kohmoto, Tomohiro; Naruto, Takuya; Takahashi, Rizu; Goji, Aya; Mori, Tatsuo; Toda, Yoshihiro; Saito, Masako; Tange, Shoichiro; Masuda, Kiyoshi; Kagami, Shoji; Imoto, Issei

2018-03-01

Rett syndrome (RTT) is a severe neurodevelopmental disorder typically affecting females. It is mainly caused by loss-of-function mutations that affect the coding sequence of exon 3 or 4 of methyl-CpG-binding protein 2 (MECP2). Severe neonatal encephalopathy resulting in death before the age of 2 years is the most common phenotype observed in males affected by a pathogenic MECP2 variant. Mutations in MECP2 exon 1 affecting the MeCP2_e1 isoform are relatively rare causes of RTT in females, and only one case of a male patient with MECP2-related severe neonatal encephalopathy caused by a mutation in MECP2 exon 1 has been reported. This is the first reported case of a male with classic RTT caused by a 5-bp duplication in the open-reading frame of MECP2 exon 1 (NM_001110792.1:c.23_27dup) that introduced a premature stop codon [p.(Ser10Argfs*36)] in the MeCP2_e1 isoform, which has been reported in one female patient with classic RTT. Therefore, both males and females displaying at least some type of MeCP2_e1 mutation may exhibit the classic RTT phenotype. © 2018 Wiley Periodicals, Inc.

SAAMBE: Webserver to Predict the Charge of Binding Free Energy Caused by Amino Acids Mutations.

Science.gov (United States)

Petukh, Marharyta; Dai, Luogeng; Alexov, Emil

2016-04-12

Predicting the effect of amino acid substitutions on protein-protein affinity (typically evaluated via the change of protein binding free energy) is important for both understanding the disease-causing mechanism of missense mutations and guiding protein engineering. In addition, researchers are also interested in understanding which energy components are mostly affected by the mutation and how the mutation affects the overall structure of the corresponding protein. Here we report a webserver, the Single Amino Acid Mutation based change in Binding free Energy (SAAMBE) webserver, which addresses the demand for tools for predicting the change of protein binding free energy. SAAMBE is an easy to use webserver, which only requires that a coordinate file be inputted and the user is provided with various, but easy to navigate, options. The user specifies the mutation position, wild type residue and type of mutation to be made. The server predicts the binding free energy change, the changes of the corresponding energy components and provides the energy minimized 3D structure of the wild type and mutant proteins for download. The SAAMBE protocol performance was tested by benchmarking the predictions against over 1300 experimentally determined changes of binding free energy and a Pearson correlation coefficient of 0.62 was obtained. How the predictions can be used for discriminating disease-causing from harmless mutations is discussed. The webserver can be accessed via http://compbio.clemson.edu/saambe_webserver/.

Current status and outlook perspectives of induced mutations for plant improvement

International Nuclear Information System (INIS)

Liu Luxiang; Guo Huijun; Zhao Linshu; Li Junhui; Gu Jiayu; ZZhao Shirong; Wang Jing

2009-01-01

Since 1928, induced mutations have played a significant role in solving world food and nutritional security problems through mutant germplasm enhancement and new mutant variety development. According to incomplete statistics, up to September 2009, induced mutations have officially released 3088 mutant cultivars in more than 170 crop species by more than 60 countries in the world. China tanks the first in the world, which has have released 802 mutant cultivars in 45 crop species, and takes more than a quarter of the total number of mutant varieties in the FAO/IAEA database. The maximum annually accumulated planting area of the mutant varieties was 9 million hectares, with an additional increase of 1.5 billion kilograms to national output of grain, cotton, oil, being converted to social and economic benefits of more than 2 billion RMB. The recent development and application of accelerator ion beam irradiation, the spaceflight environment and the other new mutation means, as well as the effective use of traditional radiation mutagenesis are becoming more active in crop improvement and new gene discovery. The advent of plant genomics and high throughput DNA techniques, such as TILLING, have opened a new era of molecular mutation breeding, which will overcome the limitations of conventional mutation breeding and play a significant role in solving China and world food security. (authors)

Timing of the uv mutagenesis in yeast: a pedigree analysis of induced recessive mutation

International Nuclear Information System (INIS)

James, A.P.; Kilbey, B.J.

1977-01-01

The mechanism of uv-induced mutation in eukaryotes was studied in individual yeast cells by a procedure that combined pedigree analysis and tetrad analysis. The technique involved the induction of recessive lethals and semilethals in G1 diploid cells. Induced frequencies were 25 and 61% at survival levels of 90 and 77%, respectively. No evidence of gross chromosome aberrations was detected. Recessive mutations that affect only one strand or that affect both strands of the DNA molecule are induced much at random among a population of cells, and both types can occur within the same cell. However, the data confirm that two-strand mutations are in the majority after a low level of irradiation. The simplest explanation involves a mechanism whereby most mutations are fixed in both strands prior to the first round of post-irradiation DNA replication. The recessive mutational consequences of irradiation are exhausted at the conclusion of the first post-irradiation cell division, although dominant-lethal sectoring continues at a high level through the second post-irradiation division. It is concluded that pyrimidine dimers that persist to the second round of DNA replication are rare or ineffective

The timing of UV mutagenesis in yeast: a pedigree analysis of induced recessive mutation.

Science.gov (United States)

James, A P; Kilbey, B J

1977-10-01

The mechanism of UV-induced mutation in eukaryotes was studied in individual yeast cells by a procedure that combined pedigree analysis and tetrad analysis. The technique involved the induction of recessive lethals and semilethals in G1 diploid cells. Induced frequencies were 25 and 61 percent at survival levels of 90 and 77 percent, respectively. No evidence of gross chromosome aberrations was detected. Recessive mutations that affect only one strand or that affect both strands of the DNA molecule are induced much at random among a population of cells, and both types can occur within the same cell. However, the data confirm that two-strand mutations are in the majority after a low level of irradiation. The simplest explanation involves a mechanism whereby most mutations are fixed in both strands prior to the first round of post-irradiation DNA replication. The recessive mutational consequences of irradiation are exhausted at the conclusion of the first post-irradiation cell division, although dominant-lethal sectoring continues at a high level through the second post-irradiation division. It is concluded that pyrimidine dimers that persist to the second round of DNA replication are rare or ineffective.

Ancient genes establish stress-induced mutation as a hallmark of cancer.

Science.gov (United States)

Cisneros, Luis; Bussey, Kimberly J; Orr, Adam J; Miočević, Milica; Lineweaver, Charles H; Davies, Paul

2017-01-01

Cancer is sometimes depicted as a reversion to single cell behavior in cells adapted to live in a multicellular assembly. If this is the case, one would expect that mutation in cancer disrupts functional mechanisms that suppress cell-level traits detrimental to multicellularity. Such mechanisms should have evolved with or after the emergence of multicellularity. This leads to two related, but distinct hypotheses: 1) Somatic mutations in cancer will occur in genes that are younger than the emergence of multicellularity (1000 million years [MY]); and 2) genes that are frequently mutated in cancer and whose mutations are functionally important for the emergence of the cancer phenotype evolved within the past 1000 million years, and thus would exhibit an age distribution that is skewed to younger genes. In order to investigate these hypotheses we estimated the evolutionary ages of all human genes and then studied the probability of mutation and their biological function in relation to their age and genomic location for both normal germline and cancer contexts. We observed that under a model of uniform random mutation across the genome, controlled for gene size, genes less than 500 MY were more frequently mutated in both cases. Paradoxically, causal genes, defined in the COSMIC Cancer Gene Census, were depleted in this age group. When we used functional enrichment analysis to explain this unexpected result we discovered that COSMIC genes with recessive disease phenotypes were enriched for DNA repair and cell cycle control. The non-mutated genes in these pathways are orthologous to those underlying stress-induced mutation in bacteria, which results in the clustering of single nucleotide variations. COSMIC genes were less common in regions where the probability of observing mutational clusters is high, although they are approximately 2-fold more likely to harbor mutational clusters compared to other human genes. Our results suggest this ancient mutational response to

Gamma ray induced somatic mutations in rose

International Nuclear Information System (INIS)

Datta, S.K.

1989-01-01

Budwood of 32 rose cultivars (Rosa spp.) was exposed to 3-4 krad of gamma rays and eyes were grafted on Rosa indica var. odorata root stock. Radiosensitivity with respect to sprouting, survival and plant height, and mutation frequency varied with the cultivar and dose of gamma rays. Somatic mutations in flower colour/shape were detected as chimera in 21 cultivars. The size of the mutant sector varied from a narrow streak on a petal to a whole flower and from a portion of a branch to an entire branch. 14 mutants were detected in M 1 V 1 , four in M 1 V 2 and three in M 1 V 3 . Maximum number of mutations was detected following 3 krad treatment. Eyes from mutant branches were grafted again on root stock and non-chimeric mutants were aimed at by vegetative propagation. Mutants from 11 cultivars only could be isolated in pure form. Isolation of non-chimeric mutants sometimes is difficult due to weak growth of a mutant branch. In such a case, all normal looking branches are removed to force a better growth of the mutant branch. It is advisable to maintain irradiated plants at least for four years with drastic pruning in each year. Nine mutants viz. 'Sharada', 'Sukumari', 'Tangerine Contempo', 'Yellow Contempo', 'Pink Contempo', 'Striped Contempo', 'Twinkle', 'Curio' and 'Light Pink Prize' have already been released as new cultivars for commercialization [ref. MBNL No. 23 and 31] and others are being multiplied and assessed. The mutation spectrum appears to be wider for the cultivars 'Contempo' and 'Imperator'. Pigment composition of the original variety is relevant for the kind of flower colour mutations that can be induced

Plant breeding: Induced mutation technology for crop improvement

International Nuclear Information System (INIS)

Novak, F.J.; Brunner, H.

1992-01-01

Plant breeding requires genetic variation of useful traits for crop improvement, but the desired variation is often lacking. Mutagenic agents, such as radiation and certain chemicals, can be used to induce mutations and generate genetic variations from which desirable mutants may be selected. After a brief summary of the methods currently employed in plant breeding, especially those inducing genetic engineering, this article describes the activities of the Plant Breeding Unit of the IAEA Laboratories at Seibersdorf, summarizing the research and development areas currently being pursued. The banana plant is chosen to exemplify the Laboratories' research

Col4a1 mutations cause progressive retinal neovascular defects and retinopathy.

Science.gov (United States)

Alavi, Marcel V; Mao, Mao; Pawlikowski, Bradley T; Kvezereli, Manana; Duncan, Jacque L; Libby, Richard T; John, Simon W M; Gould, Douglas B

2016-01-27

Mutations in collagen, type IV, alpha 1 (COL4A1), a major component of basement membranes, cause multisystem disorders in humans and mice. In the eye, these include anterior segment dysgenesis, optic nerve hypoplasia and retinal vascular tortuosity. Here we investigate the retinal pathology in mice carrying dominant-negative Col4a1 mutations. To this end, we examined retinas longitudinally in vivo using fluorescein angiography, funduscopy and optical coherence tomography. We assessed retinal function by electroretinography and studied the retinal ultrastructural pathology. Retinal examinations revealed serous chorioretinopathy, retinal hemorrhages, fibrosis or signs of pathogenic angiogenesis with chorioretinal anastomosis in up to approximately 90% of Col4a1 mutant eyes depending on age and the specific mutation. To identify the cell-type responsible for pathogenesis we generated a conditional Col4a1 mutation and determined that primary vascular defects underlie Col4a1-associated retinopathy. We also found focal activation of Müller cells and increased expression of pro-angiogenic factors in retinas from Col4a1(+/Δex41)mice. Together, our findings suggest that patients with COL4A1 and COL4A2 mutations may be at elevated risk of retinal hemorrhages and that retinal examinations may be useful for identifying patients with COL4A1 and COL4A2 mutations who are also at elevated risk of hemorrhagic strokes.

Herpesvirus telomerase RNA (vTR with a mutated template sequence abrogates herpesvirus-induced lymphomagenesis.

Directory of Open Access Journals (Sweden)

Benedikt B Kaufer

2011-10-01

Full Text Available Telomerase reverse transcriptase (TERT and telomerase RNA (TR represent the enzymatically active components of telomerase. In the complex, TR provides the template for the addition of telomeric repeats to telomeres, a protective structure at the end of linear chromosomes. Human TR with a mutation in the template region has been previously shown to inhibit proliferation of cancer cells in vitro. In this report, we examined the effects of a mutation in the template of a virus encoded TR (vTR on herpesvirus-induced tumorigenesis in vivo. For this purpose, we used the oncogenic avian herpesvirus Marek's disease virus (MDV as a natural virus-host model for lymphomagenesis. We generated recombinant MDV in which the vTR template sequence was mutated from AATCCCAATC to ATATATATAT (vAU5 by two-step Red-mediated mutagenesis. Recombinant viruses harboring the template mutation replicated with kinetics comparable to parental and revertant viruses in vitro. However, mutation of the vTR template sequence completely abrogated virus-induced tumor formation in vivo, although the virus was able to undergo low-level lytic replication. To confirm that the absence of tumors was dependent on the presence of mutant vTR in the telomerase complex, a second mutation was introduced in vAU5 that targeted the P6.1 stem loop, a conserved region essential for vTR-TERT interaction. Absence of vTR-AU5 from the telomerase complex restored virus-induced lymphoma formation. To test if the attenuated vAU5 could be used as an effective vaccine against MDV, we performed vaccination-challenge studies and determined that vaccination with vAU5 completely protected chickens from lethal challenge with highly virulent MDV. Taken together, our results demonstrate 1 that mutation of the vTR template sequence can completely abrogate virus-induced tumorigenesis, likely by the inhibition of cancer cell proliferation, and 2 that this strategy could be used to generate novel vaccine candidates

Involvement of p53 Mutation and Mismatch Repair Proteins Dysregulation in NNK-Induced Malignant Transformation of Human Bronchial Epithelial Cells

Directory of Open Access Journals (Sweden)

Ying Shen

2014-01-01

Full Text Available Genome integrity is essential for normal cellular functions and cell survival. Its instability can cause genetic aberrations and is considered as a hallmark of most cancers. To investigate the carcinogenesis process induced by tobacco-specific carcinogen NNK, we studied the dynamic changes of two important protectors of genome integrity, p53 and MMR system, in malignant transformation of human bronchial epithelial cells after NNK exposure. Our results showed that the expression of MLH1, one of the important MMR proteins, was decreased early and maintained the downregulation during the transformation in a histone modification involved and DNA methylation-independent manner. Another MMR protein PMS2 also displayed a declined expression while being in a later stage of transformation. Moreover, we conducted p53 mutation analysis and revealed a mutation at codon 273 which led to the replacement of arginine by histidine. With the mutation, DNA damage-induced activation of p53 was significantly impaired. We further reintroduced the wild-type p53 into the transformed cells, and the malignant proliferation can be abrogated by inducing cell cycle arrest and apoptosis. These findings indicate that p53 and MMR system play an important role in the initiation and progression of NNK-induced transformation, and p53 could be a potential therapeutic target for tobacco-related cancers.

Radiation equivalence of genotoxic chemicals - Validation in cultered mammalian cell lines

International Nuclear Information System (INIS)

Murthy, M.S.S.

1982-01-01

Published data on mutations induced by ionizing radiation and 6 monofunctional alkylating agents, namely EMS, MMS, ENNG, MNNG, ENU and MNU, in different cell lines (Chinese hamster ovary, Chinese hamster lung V79, mouse lymphoma L5178 and human cells) were analysed so that radiation-equivalent chemical (REC) values could be calculated. REC values thus obtained for a given alkylating agent with different cell lines fall within a narrow range suggesting its validation in cultured mammalian cell systems including human. (orig.)

A novel GJA8 mutation (p.V44A causing autosomal dominant congenital cataract.

Directory of Open Access Journals (Sweden)

Yanan Zhu

Full Text Available To examine the mechanism by which a novel connexin 50 (Cx50 mutation, Cx50 V44A, in a Chinese family causes suture-sparing autosomal dominant congenital nuclear cataracts.Family history and clinical data were recorded and direct gene sequencing was used to identify the disease-causing mutation. The Cx50 gene was cloned from a human lens cDNA library. Connexin protein distributions were assessed by fluorescence microscopy. Hemichannel functions were analyzed by dye uptake assay. Formation of functional channels was assessed by dye transfer experiments.Direct sequencing of the candidate GJA8 gene revealed a novel c.131T>C transition in exon 2, which cosegregated with the disease in the family and resulted in the substitution of a valine residue with alanine at codon 44 (p. V44A in the extracellular loop 1 of the Cx50 protein. Both Cx50 and Cx50V44A formed functional gap junctions, as shown by the neurobiotin transfer assay. However, unlike wild-type Cx50, Cx50V44A was unable to form open hemichannels in dye uptake experiments.This work identified a unique congenital cataract in the Chinese population, caused by the novel mutation Cx50V44A, and it showed that the V44A mutation specifically impairs the gating of the hemichannels but not the gap junction channels. The dysfunctional hemichannels resulted in the development of human congenital cataracts.

Gain-of-function mutations in RIT1 cause Noonan syndrome, a RAS/MAPK pathway syndrome.

Science.gov (United States)

Aoki, Yoko; Niihori, Tetsuya; Banjo, Toshihiro; Okamoto, Nobuhiko; Mizuno, Seiji; Kurosawa, Kenji; Ogata, Tsutomu; Takada, Fumio; Yano, Michihiro; Ando, Toru; Hoshika, Tadataka; Barnett, Christopher; Ohashi, Hirofumi; Kawame, Hiroshi; Hasegawa, Tomonobu; Okutani, Takahiro; Nagashima, Tatsuo; Hasegawa, Satoshi; Funayama, Ryo; Nagashima, Takeshi; Nakayama, Keiko; Inoue, Shin-Ichi; Watanabe, Yusuke; Ogura, Toshihiko; Matsubara, Yoichi

2013-07-11

RAS GTPases mediate a wide variety of cellular functions, including cell proliferation, survival, and differentiation. Recent studies have revealed that germline mutations and mosaicism for classical RAS mutations, including those in HRAS, KRAS, and NRAS, cause a wide spectrum of genetic disorders. These include Noonan syndrome and related disorders (RAS/mitogen-activated protein kinase [RAS/MAPK] pathway syndromes, or RASopathies), nevus sebaceous, and Schimmelpenning syndrome. In the present study, we identified a total of nine missense, nonsynonymous mutations in RIT1, encoding a member of the RAS subfamily, in 17 of 180 individuals (9%) with Noonan syndrome or a related condition but with no detectable mutations in known Noonan-related genes. Clinical manifestations in the RIT1-mutation-positive individuals are consistent with those of Noonan syndrome, which is characterized by distinctive facial features, short stature, and congenital heart defects. Seventy percent of mutation-positive individuals presented with hypertrophic cardiomyopathy; this frequency is high relative to the overall 20% incidence in individuals with Noonan syndrome. Luciferase assays in NIH 3T3 cells showed that five RIT1 alterations identified in children with Noonan syndrome enhanced ELK1 transactivation. The introduction of mRNAs of mutant RIT1 into 1-cell-stage zebrafish embryos was found to result in a significant increase of embryos with craniofacial abnormalities, incomplete looping, a hypoplastic chamber in the heart, and an elongated yolk sac. These results demonstrate that gain-of-function mutations in RIT1 cause Noonan syndrome and show a similar biological effect to mutations in other RASopathy-related genes. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

CCDC103 mutations cause primary ciliary dyskinesia by disrupting assembly of ciliary dynein arms

Science.gov (United States)

Panizzi, Jennifer R.; Becker-Heck, Anita; Castleman, Victoria H.; Al-Mutairi, Dalal; Liu, Yan; Loges, Niki T.; Pathak, Narendra; Austin-Tse, Christina; Sheridan, Eamonn; Schmidts, Miriam; Olbrich, Heike; Werner, Claudius; Häffner, Karsten; Hellman, Nathan; Chodhari, Rahul; Gupta, Amar; Kramer-Zucker, Albrecht; Olale, Felix; Burdine, Rebecca D.; Schier, Alexander F.; O’Callaghan, Christopher; Chung, Eddie MK; Reinhardt, Richard; Mitchison, Hannah M.; King, Stephen M.; Omran, Heymut; Drummond, Iain A.

2012-01-01

Cilia are essential for fertilization, respiratory clearance, cerebrospinal fluid circulation, and to establish laterality1. Cilia motility defects cause Primary Ciliary Dyskinesia (PCD, MIM 242650), a disorder affecting 1:15-30,000 births. Cilia motility requires the assembly of multisubunit dynein arms that drive cilia bending2. Despite progress in understanding the genetic basis of PCD, mutations remain to be identified for several PCD linked loci3. Here we show that the zebrafish cilia paralysis mutant schmalhanstn222 (smh) mutant encodes the coiled-coil domain containing 103 protein (Ccdc103), a foxj1a regulated gene. Screening 146 unrelated PCD families identified patients in six families with reduced outer dynein arms, carrying mutations in CCDC103. Dynein arm assembly in smh mutant zebrafish was rescued by wild-type but not mutant human CCDC103. Chlamydomonas Ccdc103 functions as a tightly bound, axoneme-associated protein. The results identify Ccdc103 as a novel dynein arm attachment factor that when mutated causes Primary Ciliary Dyskinesia. PMID:22581229

Induced mutation for accelerated domestication: a case study of winged bean (Psophocarpus tetragonolobus (L.) (DC)

International Nuclear Information System (INIS)

Klu, G. Y. P.

2000-01-01

Induced mutations have the ability to increase the rate of domestication of the many under exploited species of plants that may be potentially useful as source of food, forage and industrial raw materials. The process of domestication has been conditioned by single or major gene mutations. The role of mutagenesis in speeding up domestication, which is species dependent, is outlined in this paper. A case study of the role of induced mutations in the domestication of winged bean (Psophocarpus tetragonobolus) is also presented (au)

De Novo GMNN Mutations Cause Autosomal-Dominant Primordial Dwarfism Associated with Meier-Gorlin Syndrome.

Science.gov (United States)

Burrage, Lindsay C; Charng, Wu-Lin; Eldomery, Mohammad K; Willer, Jason R; Davis, Erica E; Lugtenberg, Dorien; Zhu, Wenmiao; Leduc, Magalie S; Akdemir, Zeynep C; Azamian, Mahshid; Zapata, Gladys; Hernandez, Patricia P; Schoots, Jeroen; de Munnik, Sonja A; Roepman, Ronald; Pearring, Jillian N; Jhangiani, Shalini; Katsanis, Nicholas; Vissers, Lisenka E L M; Brunner, Han G; Beaudet, Arthur L; Rosenfeld, Jill A; Muzny, Donna M; Gibbs, Richard A; Eng, Christine M; Xia, Fan; Lalani, Seema R; Lupski, James R; Bongers, Ernie M H F; Yang, Yaping

2015-12-03

Meier-Gorlin syndrome (MGS) is a genetically heterogeneous primordial dwarfism syndrome known to be caused by biallelic loss-of-function mutations in one of five genes encoding pre-replication complex proteins: ORC1, ORC4, ORC6, CDT1, and CDC6. Mutations in these genes cause disruption of the origin of DNA replication initiation. To date, only an autosomal-recessive inheritance pattern has been described in individuals with this disorder, with a molecular etiology established in about three-fourths of cases. Here, we report three subjects with MGS and de novo heterozygous mutations in the 5' end of GMNN, encoding the DNA replication inhibitor geminin. We identified two truncating mutations in exon 2 (the 1(st) coding exon), c.16A>T (p.Lys6(∗)) and c.35_38delTCAA (p.Ile12Lysfs(∗)4), and one missense mutation, c.50A>G (p.Lys17Arg), affecting the second-to-last nucleotide of exon 2 and possibly RNA splicing. Geminin is present during the S, G2, and M phases of the cell cycle and is degraded during the metaphase-anaphase transition by the anaphase-promoting complex (APC), which recognizes the destruction box sequence near the 5' end of the geminin protein. All three GMNN mutations identified alter sites 5' to residue Met28 of the protein, which is located within the destruction box. We present data supporting a gain-of-function mechanism, in which the GMNN mutations result in proteins lacking the destruction box and hence increased protein stability and prolonged inhibition of replication leading to autosomal-dominant MGS. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

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...

Neutron-induced mutation experiments. Comprehensive report, March 1, 1977-August 31, 1980

International Nuclear Information System (INIS)

Abrahamson, S.

1981-02-01

Neutron-induced X-linked lethal mutations were induced in Drosophila melanogaster oogonia at energies of .43, .66, 2, and 6 MeV. The 37 irradiations were carried out at the RARAF facility at Brookhaven National Laboratory. RBE's (relative to x-ray data similarly collected) were calculated to be .43 MeV to 4.8; .66 MeV to 4.0; 2 MeV to 3.2; and 6 MeV to 2.9. The dose/frequency response curves for all energies best fit a linear rather than a linear-quadratic model following regression analyses. Control data for specific locus mutations (420,000 tests) were gathered. This data, combined with other data (both X-linked lethal and specific locus) has been used to estimate the number of loci on the X-chromosome of Drosophila which can mutate to recessive lethals

Induced mutations in highly heterozygous vegetatively propagated grasses

International Nuclear Information System (INIS)

Powell, J.B.

1976-01-01

Experience with mutation induction of turf and forage grasses indicates that much progress can be achieved by this method. More than 300 mutations have been produced in our laboratory in the cultivars Tifgreen and Tifdwarf bermudagrass (Cynodon sp.). In the Tifway and Tifcote bermudagrasses we have demonstrated similar mutation responses. The first three clones are triploids and Tifcote is a probable tetraploid. No seeds are set on these clones. Two clones of bermudagrass, Coastal and Coastcross-1, occupy millions of hectares in the USA. Both are mutable and are known to be hybrids with 36 chromosomes. Biotypes of dallisgrass (Paspalum dilatatum Poir.) exist with 40 and 50 chromosomes and reproduce as sexual and obligate apomictic forms. Gamma-ray and thermal-neutron treatment of seed of these biotypes produced mutants that maintained the maternal characteristics in subsequent generations. Bahiagrass (Paspalum notatum Fluegge) also has sexual and apomictic biotypes. Some success was indicated for increased seed set by mutagen treatment. Kentucky bluegrass (Poa pratensis L.) is a facultative apomict with varying numbers of chromosomes in different cultivars. Gamma-ray mutagen treatment of rhizomes produced numerous mutations for plant type and disease reaction. Most mutations perpetuate themselves through the seed. The characteristic in common with all these grasses is their heterozygosity, which is maintained by the vegetative propagation or apomictic mode of reproduction. The experience in using ionizing radiation to induce heritable changes in these vegetatively propagated grasses is one of considerable success. Mutation rates in some of these irradiated grasses exceeded 65% and aberrant plants with characteristics previously never observed were found. Numerous hemizygous and heterozygous loci seem to be a sensitive target for mutagens. (author)

Characterization of two Turkish beta-hexosaminidase mutations causing Tay-Sachs disease.

Science.gov (United States)

Ozkara, Hatice Asuman; Sandhoff, Konrad

2003-04-01

Two homoallelic mutations have recently been identified in the alpha-subunit of hexosaminidase A (EC 3.2.1.52) causing the infantile form of Tay-Sachs disease in Turkish patients. Both of these mutations, a 12 bp deletion (1096-1107 or 1098-1108 or 1099-1109) in exon 10 and a point mutation (G1362 to A, Gly454 to Asp) in exon 12, are located in the catalytic domain of the hexosaminidase alpha-chain. In order to determine whether these mutations affect the function of the catalytic domain or result in an instable protein, both mutant cDNAs were overexpressed in COS-1 cells. As judged by Western blotting, transfections of wild-type cDNA produced pro-alpha-chain and mature alpha-chain in parallel with a fivefold increase in cellular hexosaminidase activity using the synthetic substrate 4-methylumbelliferyl beta-N-acetylglucosamine 6-sulfate (MUGS). However, both mutants produced only pro-alpha-chains, although no mature form or detectable hexosaminidase activity towards two different synthetic substrates was observed. These data are consistent with the biochemical phenotype of infantile Tay-Sachs disease. We conclude that the overexpressed mutant pro-alpha-chains were misfolded and could not undergo further proteolytic processing to the active form of the enzyme in the lysosome.

Somatic USP8 Gene Mutations Are a Common Cause of Pediatric Cushing Disease.

Science.gov (United States)

Faucz, Fabio R; Tirosh, Amit; Tatsi, Christina; Berthon, Annabel; Hernández-Ramírez, Laura C; Settas, Nikolaos; Angelousi, Anna; Correa, Ricardo; Papadakis, Georgios Z; Chittiboina, Prashant; Quezado, Martha; Pankratz, Nathan; Lane, John; Dimopoulos, Aggeliki; Mills, James L; Lodish, Maya; Stratakis, Constantine A

2017-08-01

Somatic mutations in the ubiquitin-specific protease 8 (USP8) gene have been recently identified as the most common genetic alteration in patients with Cushing disease (CD). However, the frequency of these mutations in the pediatric population has not been extensively assessed. We investigated the status of the USP8 gene at the somatic level in a cohort of pediatric patients with corticotroph adenomas. The USP8 gene was fully sequenced in both germline and tumor DNA samples from 42 pediatric patients with CD. Clinical, biochemical, and imaging data were compared between patients with and without somatic USP8 mutations. Five different USP8 mutations (three missense, one frameshift, and one in-frame deletion) were identified in 13 patients (31%), all of them located in exon 14 at the previously described mutational hotspot, affecting the 14-3-3 binding motif of the protein. Patients with somatic mutations were older at disease presentation [mean 5.1 ± 2.1 standard deviation (SD) vs 13.1 ± 3.6 years, P = 0.03]. Levels of urinary free cortisol, midnight serum cortisol, and adrenocorticotropic hormone, as well as tumor size and frequency of invasion of the cavernous sinus, were not significantly different between the two groups. However, patients harboring somatic USP8 mutations had a higher likelihood of recurrence compared with patients without mutations (46.2% vs 10.3%, P = 0.009). Somatic USP8 gene mutations are a common cause of pediatric CD. Patients harboring a somatic mutation had a higher likelihood of tumor recurrence, highlighting the potential importance of this molecular defect for the disease prognosis and the development of targeted therapeutic options. Copyright © 2017 Endocrine Society

Mutations in PYCR1 cause cutis laxa with progeroid features.

Science.gov (United States)

Reversade, Bruno; Escande-Beillard, Nathalie; Dimopoulou, Aikaterini; Fischer, Björn; Chng, Serene C; Li, Yun; Shboul, Mohammad; Tham, Puay-Yoke; Kayserili, Hülya; Al-Gazali, Lihadh; Shahwan, Monzer; Brancati, Francesco; Lee, Hane; O'Connor, Brian D; Schmidt-von Kegler, Mareen; Merriman, Barry; Nelson, Stanley F; Masri, Amira; Alkazaleh, Fawaz; Guerra, Deanna; Ferrari, Paola; Nanda, Arti; Rajab, Anna; Markie, David; Gray, Mary; Nelson, John; Grix, Arthur; Sommer, Annemarie; Savarirayan, Ravi; Janecke, Andreas R; Steichen, Elisabeth; Sillence, David; Hausser, Ingrid; Budde, Birgit; Nürnberg, Gudrun; Nürnberg, Peter; Seemann, Petra; Kunkel, Désirée; Zambruno, Giovanna; Dallapiccola, Bruno; Schuelke, Markus; Robertson, Stephen; Hamamy, Hanan; Wollnik, Bernd; Van Maldergem, Lionel; Mundlos, Stefan; Kornak, Uwe

2009-09-01

Autosomal recessive cutis laxa (ARCL) describes a group of syndromal disorders that are often associated with a progeroid appearance, lax and wrinkled skin, osteopenia and mental retardation. Homozygosity mapping in several kindreds with ARCL identified a candidate region on chromosome 17q25. By high-throughput sequencing of the entire candidate region, we detected disease-causing mutations in the gene PYCR1. We found that the gene product, an enzyme involved in proline metabolism, localizes to mitochondria. Altered mitochondrial morphology, membrane potential and increased apoptosis rate upon oxidative stress were evident in fibroblasts from affected individuals. Knockdown of the orthologous genes in Xenopus and zebrafish led to epidermal hypoplasia and blistering that was accompanied by a massive increase of apoptosis. Our findings link mutations in PYCR1 to altered mitochondrial function and progeroid changes in connective tissues.

Inflammatory peeling skin syndrome caused a novel mutation in CDSN.

Science.gov (United States)

Telem, Dana Fuchs; Israeli, Shirli; Sarig, Ofer; Sprecher, Eli

2012-04-01

Generalized peeling skin syndrome (PSS) is a rare autosomal recessive dermatosis manifesting with continuous exfoliation of the stratum corneum. The inflammatory (type B) subtype of PSS was recently found to be caused by deleterious mutations in the CDSN gene encoding corneodesmosin, a major component of desmosomal junctions in the uppermost layers of the epidermis. In the present study, we assessed a 10-month-old baby, who presented with generalized superficial peeling of the skin. Using PCR amplification and direct sequencing, we identified the third PSS-associated mutation in CDSN, a homozygous 4 bp duplication in the second exon of the gene (c.164_167dup GCCT; p.Thr57ProfsX6). These data further support the notion that corneodesmosin deficiency impairs cell-cell adhesion in the upper epidermis, paving the way for an abnormal inflammatory response due to epidermal barrier disruption.

Niacin deficiency delays DNA excision repair and increases spontaneous and nitrosourea-induced chromosomal instability in rat bone marrow.

Science.gov (United States)

Kostecki, Lisa M; Thomas, Megan; Linford, Geordie; Lizotte, Matthew; Toxopeus, Lori; Bartleman, Anne-Pascale; Kirkland, James B

2007-12-01

We have shown that niacin deficiency impairs poly(ADP-ribose) formation and enhances sister chromatid exchanges and micronuclei formation in rat bone marrow. We designed the current study to investigate the effects of niacin deficiency on the kinetics of DNA repair following ethylation, and the accumulation of double strand breaks, micronuclei (MN) and chromosomal aberrations (CA). Weanling male Long-Evans rats were fed niacin deficient (ND), or pair fed (PF) control diets for 3 weeks. We examined repair kinetics by comet assay in the 36h following a single dose of ethylnitrosourea (ENU) (30mg/kg bw). There was no effect of ND on mean tail moment (MTM) before ENU treatment, or on the development of strand breaks between 0 and 8h after ENU. Repair kinetics between 12 and 30h were significantly delayed by ND, with a doubling of area under the MTM curve during this period. O(6)-ethylation of guanine peaked by 1.5h, was largely repaired by 15h, and was also delayed in bone marrow cells from ND rats. ND significantly enhanced double strand break accumulation at 24h after ENU. ND alone increased chromosome and chromatid breaks (four- and two-fold). ND alone caused a large increase in MN, and this was amplified by ENU treatment. While repair kinetics suggest that ND may be acting by creating catalytically inactive PARP molecules with a dominant-negative effect on repair processes, the effect of ND alone on O(6)-ethylation, MN and CA, in the absence of altered comet results, suggests additional mechanisms are also leading to chromosomal instability. These data support the idea that the bone marrow cells of niacin deficient cancer patients may be more sensitive to the side effects of genotoxic chemotherapy, resulting in acute bone marrow suppression and chronic development of secondary leukemias.

Homozygous YME1L1 mutation causes mitochondriopathy with optic atrophy and mitochondrial network fragmentation.

Science.gov (United States)

Hartmann, Bianca; Wai, Timothy; Hu, Hao; MacVicar, Thomas; Musante, Luciana; Fischer-Zirnsak, Björn; Stenzel, Werner; Gräf, Ralph; van den Heuvel, Lambert; Ropers, Hans-Hilger; Wienker, Thomas F; Hübner, Christoph; Langer, Thomas; Kaindl, Angela M

2016-08-06

Mitochondriopathies often present clinically as multisystemic disorders of primarily high-energy consuming organs. Assembly, turnover, and surveillance of mitochondrial proteins are essential for mitochondrial function and a key task of AAA family members of metalloproteases. We identified a homozygous mutation in the nuclear encoded mitochondrial escape 1-like 1 gene YME1L1, member of the AAA protease family, as a cause of a novel mitochondriopathy in a consanguineous pedigree of Saudi Arabian descent. The homozygous missense mutation, located in a highly conserved region in the mitochondrial pre-sequence, inhibits cleavage of YME1L1 by the mitochondrial processing peptidase, which culminates in the rapid degradation of YME1L1 precursor protein. Impaired YME1L1 function causes a proliferation defect and mitochondrial network fragmentation due to abnormal processing of OPA1. Our results identify mutations in YME1L1 as a cause of a mitochondriopathy with optic nerve atrophy highlighting the importance of YME1L1 for mitochondrial functionality in humans.

Homozygous YME1L1 mutation causes mitochondriopathy with optic atrophy and mitochondrial network fragmentation

Science.gov (United States)

Hartmann, Bianca; Wai, Timothy; Hu, Hao; MacVicar, Thomas; Musante, Luciana; Fischer-Zirnsak, Björn; Stenzel, Werner; Gräf, Ralph; van den Heuvel, Lambert; Ropers, Hans-Hilger; Wienker, Thomas F; Hübner, Christoph; Langer, Thomas; Kaindl, Angela M

2016-01-01

Mitochondriopathies often present clinically as multisystemic disorders of primarily high-energy consuming organs. Assembly, turnover, and surveillance of mitochondrial proteins are essential for mitochondrial function and a key task of AAA family members of metalloproteases. We identified a homozygous mutation in the nuclear encoded mitochondrial escape 1-like 1 gene YME1L1, member of the AAA protease family, as a cause of a novel mitochondriopathy in a consanguineous pedigree of Saudi Arabian descent. The homozygous missense mutation, located in a highly conserved region in the mitochondrial pre-sequence, inhibits cleavage of YME1L1 by the mitochondrial processing peptidase, which culminates in the rapid degradation of YME1L1 precursor protein. Impaired YME1L1 function causes a proliferation defect and mitochondrial network fragmentation due to abnormal processing of OPA1. Our results identify mutations in YME1L1 as a cause of a mitochondriopathy with optic nerve atrophy highlighting the importance of YME1L1 for mitochondrial functionality in humans. DOI: http://dx.doi.org/10.7554/eLife.16078.001 PMID:27495975

Rice breeding with induced mutations

Energy Technology Data Exchange (ETDEWEB)

1968-06-01

The Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture decided in 1964 to organize a co-ordinated research programme on the use of induced mutations in rice breeding. The programme was organized within the framework of activities of the International Rice Commission. This is a report of the Third Co-ordination Meeting of the participants, which was held in Taipei, 5-9 June 1967. As the projects, which together make up the co-ordinated programme, are at different stages of progress, the report contains a variety of papers including completed studies, field and progress reports, and highlights of the discussions with some additional recommendations prepared by the participants. Refs, figs and tabs.

Lack of chemically induced mutation in repair-deficient mutants of yeast

International Nuclear Information System (INIS)

Prakash, L.

1974-01-01

Two genes, rad6 and rad9, that confer radiation sensitivity in the yeast Saccharomyces cerevisiae also greatly reduce the frequency of chemically-induced reversions of a tester mutant cyc1-131, which is a chain initiation mutant in the structural gene determining iso-1-cytochrome c. Mutations induced by ethyl methanesulfonate (EMS), diethyl sulfate (DES), methyl methanesulfonate (MMS), dimethyl sulfate (DMS), nitroquinoline oxide (NQO), nitrosoguanidine (NTG), nitrogen mustard (HN2), β-propiolactone, and tritiated uridine, as well as mutations induced by ultraviolet light (UV) and ionizing radiation were greatly diminished in strains homozygous for either the rad6 or rad9 gene. Nitrous acid and nitrosoimidazolidone (NIL), on the other hand, were highly mutagenic in these repair-deficient mutants, and at low doses, these mutagens acted with about the same efficiency as in the normal RAD strain. At high doses of either nitrous acid or NIL, however, reversion frequencies were significantly reduced in the two rad mutants compared to normal strains. Although both rad mutants are immutable to about the same extent, the rad9 strains tend to be less sensitive to the lethal effect of chemical mutagens than rad6 strains. It is concluded that yeast requires a functional repair system for mutation induction by chemical agents. (auth)

Lack of chemically induced mutation in repair-deficient mutants of yeast.

Science.gov (United States)

Prakash, L

1974-12-01

Two genes, rad6 and rad9, that confer radiation sensitivity in the yeast Saccharomyces cerevisiae also greatly reduce the frequency of chemically-induced reversions of a tester mutant cyc1-131, which is a chain initiation mutant in the structural gene determining iso-1-cytochrome c. Mutations induced by ethyl methanesulfonate (EMS), diethyl sulfate (DES), methyl methanesulfonate (MMS), dimethyl sulfate (DMS), nitroquinoline oxide (NQO), nitrosoguanidine (NTG), nitrogen mustard (HN2), beta-propiolactone, and tritiated uridine, as well as mutations induced by ultraviolet light (UV) and ionizing radiation were greatly diminished in strains homozygous for either the rad6 or rad9 gene. Nitrous acid and nitrosoimidazolidone (NIL), on the other hand, were highly mutagenic in these repair-deficient mutants, and at low doses, these mutagens acted with about the same efficiency as in the normal RAD strain. At high doses of either nitrous acid or NIL, however, reversion frequencies were significantly reduced in the two rad mutants compared to normal strains. Although both rad mutants are immutable to about the same extent, the rad9 strains tend to be less sensitive to the lethal effect of chemical mutagens than rad6 strains. It is concluded that yeast requires a functional repair system for mutation induction by chemical agents.

Plant cultivars derived from mutation induction or the use of induced mutants in cross breeding

International Nuclear Information System (INIS)

Micke, A.; Maluszynski, M.; Donini, B.

1985-01-01

Since 1969 we have collected information on cultivated varieties of plants, developed by using induced mutations. Whenever we learn about a cultivar presumably derived from an induced mutant or from use of mutants in crosses. we mail a questionnaire to the breeder. The information gathered in this way is stored in our file on ''Mutant Varieties''. Excerpts are published regularly in the form of a list in the FAO/IAEA Mutation Breeding Newsletter. Our mutant variety list has repeatedly provided a basis for analyses on the value and prospects of mutation breeding

Plant cultivars derived from mutation induction or the use of induced mutants in cross breeding

Energy Technology Data Exchange (ETDEWEB)

Micke, A; Maluszynski, M; Donini, B [Joint FAO/IAEA Division, Plant Breeding and Genetics Section, Vienna (Austria)

1985-05-01

Since 1969 we have collected information on cultivated varieties of plants, developed by using induced mutations. Whenever we learn about a cultivar presumably derived from an induced mutant or from use of mutants in crosses. we mail a questionnaire to the breeder. The information gathered in this way is stored in our file on ''Mutant Varieties''. Excerpts are published regularly in the form of a list in the FAO/IAEA Mutation Breeding Newsletter. Our mutant variety list has repeatedly provided a basis for analyses on the value and prospects of mutation breeding.

The m.3291T>C mt-tRNALeu(UUR) mutation is definitely pathogenic and causes multisystem mitochondrial disease

Science.gov (United States)

Yarham, John W.; Blakely, Emma L.; Alston, Charlotte L.; Roberts, Mark E.; Ealing, John; Pal, Piyali; Turnbull, Douglass M.; McFarland, Robert; Taylor, Robert W.

2013-01-01

Mitochondrial tRNA point mutations are important causes of human disease, and have been associated with a diverse range of clinical phenotypes. Definitively proving the pathogenicity of any given mt-tRNA mutation requires combined molecular, genetic and functional studies. Subsequent evaluation of the mutation using a pathogenicity scoring system is often very helpful in concluding whether or not the mutation is causing disease. Despite several independent reports linking the m.3291T>C mutation to disease in humans, albeit in association with several different phenotypes, its pathogenicity remains controversial. A lack of conclusive functional evidence and an over-emphasis on the poor evolutionary conservation of the affected nucleotide have contributed to this controversy. Here we describe an adult patient who presented with deafness and lipomas and evidence of mitochondrial abnormalities in his muscle biopsy, who harbours the m.3291T > C mutation, providing conclusive evidence of pathogenicity through analysis of mutation segregation with cytochrome c oxidase (COX) deficiency in single muscle fibres, underlining the importance of performing functional studies when assessing pathogenicity. PMID:23273904

A novel ICK mutation causes ciliary disruption and lethal endocrine-cerebro-osteodysplasia syndrome.

Science.gov (United States)

Oud, Machteld M; Bonnard, Carine; Mans, Dorus A; Altunoglu, Umut; Tohari, Sumanty; Ng, Alvin Yu Jin; Eskin, Ascia; Lee, Hane; Rupar, C Anthony; de Wagenaar, Nathalie P; Wu, Ka Man; Lahiry, Piya; Pazour, Gregory J; Nelson, Stanley F; Hegele, Robert A; Roepman, Ronald; Kayserili, Hülya; Venkatesh, Byrappa; Siu, Victoria M; Reversade, Bruno; Arts, Heleen H

2016-01-01

Endocrine-cerebro-osteodysplasia (ECO) syndrome [MIM:612651] caused by a recessive mutation (p.R272Q) in Intestinal cell kinase (ICK) shows significant clinical overlap with ciliary disorders. Similarities are strongest between ECO syndrome, the Majewski and Mohr-Majewski short-rib thoracic dysplasia (SRTD) with polydactyly syndromes, and hydrolethalus syndrome. In this study, we present a novel homozygous ICK mutation in a fetus with ECO syndrome and compare the effect of this mutation with the previously reported ICK variant on ciliogenesis and cilium morphology. Through homozygosity mapping and whole-exome sequencing, we identified a second variant (c.358G > T; p.G120C) in ICK in a Turkish fetus presenting with ECO syndrome. In vitro studies of wild-type and mutant mRFP-ICK (p.G120C and p.R272Q) revealed that, in contrast to the wild-type protein that localizes along the ciliary axoneme and/or is present in the ciliary base, mutant proteins rather enrich in the ciliary tip. In addition, immunocytochemistry revealed a decreased number of cilia in ICK p.R272Q-affected cells. Through identification of a novel ICK mutation, we confirm that disruption of ICK causes ECO syndrome, which clinically overlaps with the spectrum of ciliopathies. Expression of ICK-mutated proteins result in an abnormal ciliary localization compared to wild-type protein. Primary fibroblasts derived from an individual with ECO syndrome display ciliogenesis defects. In aggregate, our findings are consistent with recent reports that show that ICK regulates ciliary biology in vitro and in mice, confirming that ECO syndrome is a severe ciliopathy.

Molecular alterations underlying the spontaneous and γ-ray-induced point mutations at the white locus of Drosophila Melanogaster

International Nuclear Information System (INIS)

Aleksandrova, M.V.; Lapidus, I.L.; Aleksandrov, I.D.; Karpovskij, A.L.

1996-01-01

The white locus in D.Melanogaster was selected as a target gene for the study of the mutational spectra of spontaneously arising and radiation-induced gene mutations in a whole organism. Analysis of 6 spontaneous and 73 γ-ray-induced white mutations by a combination of cytological, genetic and molecular techniques revealed that on the chromosomal and genetic levels all spontaneous mutations showed themselves to be point mutants. The share of such mutants among all heritable radiation-induced gene mutations is about 40%, whereas the rest ones are due to exchange breaks (8%) as well as multilocus, single-locus or partial-locus (intragenic) deletions (52%). The DNAs from 4 spontaneous and 17 γ-ray-induced point mutants were analysed by Southern blot-hybridization. The three spontaneous and 7 radiation mutants showed an altered DNA sequence at the left (distal) half of the white gene due to insertion or DNA rearrangement. The rest (58%) of the radiation-induced point mutations did not indicate any alternations in this part of the gene as detected by this technique and probes employed. 15 refs., 3 figs., 1 tab

Two novel mutations in thymidine kinase-2 cause early onset fatal encephalomyopathy and severe mtDNA depletion.

Science.gov (United States)

Lesko, Nicole; Naess, Karin; Wibom, Rolf; Solaroli, Nicola; Nennesmo, Inger; von Döbeln, Ulrika; Karlsson, Anna; Larsson, Nils-Göran

2010-03-01

Deficiency of thymidine kinase-2 (TK2) has been described in children with early onset fatal skeletal myopathy. TK2 is a mitochondrial deoxyribonucleoside kinase required for the phosphorylation of deoxycytidine and deoxythymidine and hence is vital for the maintenance of a balanced mitochondrial dNTP pool in post-mitotic tissues. We describe a patient with two novel TK2 mutations, which caused disease onset shortly after birth and death at the age of three months. One mutation (219insCG) generated an early stop codon, thus preventing the synthesis of a functional protein. The second mutation (R130W) resulted in an amino acid substitution, which caused a severe reduction (TK2 enzyme activity. These two novel TK2 mutations cause an extremely severe phenotype with overwhelming central nervous system symptoms not commonly seen in patients with TK2-deficiency. We conclude that the severe clinical presentation in this patient was due to a virtual lack of mitochondrial TK2 activity. Copyright 2009 Elsevier B.V. All rights reserved.

Non-homologous end joining dependency of {gamma}-irradiation-induced adaptive frameshift mutation formation in cell cycle-arrested yeast cells

Energy Technology Data Exchange (ETDEWEB)

Heidenreich, Erich [Institute of Cancer Research, Division of Molecular Genetics, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)]. E-mail: erich.heidenreich@meduniwien.ac.at; Eisler, Herfried [Institute of Cancer Research, Division of Molecular Genetics, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)

2004-11-22

There is a strong selective pressure favoring adaptive mutations which relieve proliferation-limiting adverse living conditions. Due to their importance for evolution and pathogenesis, we are interested in the mechanisms responsible for the formation of such adaptive, gain-of-fitness mutations in stationary-phase cells. During previous studies on the occurrence of spontaneous reversions of an auxotrophy-causing frameshift allele in the yeast Saccharomyces cerevisiae, we noticed that about 50% of the adaptive reversions depended on a functional non-homologous end joining (NHEJ) pathway of DNA double-strand break (DSB) repair. Here, we show that the occasional NHEJ component Pol4, which is the yeast ortholog of mammalian DNA polymerase lambda, is not required for adaptive mutagenesis. An artificially imposed excess of DSBs by {gamma}-irradiation resulted in a dramatic increase in the incidence of adaptive, cell cycle arrest-releasing frameshift reversions. By the use of DNA ligase IV-deficient strains we detected that the majority of the {gamma}-induced adaptive mutations were also dependent on a functional NHEJ pathway. This suggests that the same mutagenic NHEJ mechanism acts on spontaneously arising as well as on ionizing radiation-induced DSBs. Inaccuracy of the NHEJ repair pathway may extensively contribute to the incidence of frameshift mutations in resting (non-dividing) eukaryotic cells, and thus act as a driving force in tumor development.

Non-homologous end joining dependency of γ-irradiation-induced adaptive frameshift mutation formation in cell cycle-arrested yeast cells

International Nuclear Information System (INIS)

Heidenreich, Erich; Eisler, Herfried

2004-01-01

There is a strong selective pressure favoring adaptive mutations which relieve proliferation-limiting adverse living conditions. Due to their importance for evolution and pathogenesis, we are interested in the mechanisms responsible for the formation of such adaptive, gain-of-fitness mutations in stationary-phase cells. During previous studies on the occurrence of spontaneous reversions of an auxotrophy-causing frameshift allele in the yeast Saccharomyces cerevisiae, we noticed that about 50% of the adaptive reversions depended on a functional non-homologous end joining (NHEJ) pathway of DNA double-strand break (DSB) repair. Here, we show that the occasional NHEJ component Pol4, which is the yeast ortholog of mammalian DNA polymerase lambda, is not required for adaptive mutagenesis. An artificially imposed excess of DSBs by γ-irradiation resulted in a dramatic increase in the incidence of adaptive, cell cycle arrest-releasing frameshift reversions. By the use of DNA ligase IV-deficient strains we detected that the majority of the γ-induced adaptive mutations were also dependent on a functional NHEJ pathway. This suggests that the same mutagenic NHEJ mechanism acts on spontaneously arising as well as on ionizing radiation-induced DSBs. Inaccuracy of the NHEJ repair pathway may extensively contribute to the incidence of frameshift mutations in resting (non-dividing) eukaryotic cells, and thus act as a driving force in tumor development

Induced mutation for disease resistance in legumes

International Nuclear Information System (INIS)

Bravo, A.

1984-01-01

Mutation breeding has been used for developing genotypes that may contain resistance to: a) A necrotic strain of common mosaic virus, in common bean (Phaseolus vulgaris L.); b) Soil fungi causing root rots in chickpea (Cicer arietinum L.); c) The fungus Uromyces fabae that causes rust in lentil plants (Lens culinaria). Seeds of these three species were treated with gamma rays in doses of 1,000, 3,000, 6,000, and 9,000 rads. Treated materials and controls were grown during 1979. Chickpea M2 plants were grown in a naturally infested soil with soil-borne fungi. Lentil plants were sprayed with a suspension of spores of the rust fungus. Common bean M2 plants were sprayed with a solution containing virus particles. Ninety-three symptomless chickpea plants were identified in the M2 population. For lentil there were 47 symptomless plants and for common bean, 244 M2 plants with minor virus damage. Eight M3 progenies of chickpea, originated from symptomless M2 plants, had a high rate of survival and showed none or very little damage by root rots. In addition, some morphological changes were detected in other M3 chickpea progenies. Two progenies had larger leaflets, as compared to the control plants and those of other progenies. One progeny showed a more erect growth habit. These new traits have been attributed to genetic changes induced by the radiation treatments. By contrast to these promising results with chickpea no progress has been detected in the plant populations of common bean and lentil. (author)

Loss of stability and hydrophobicity of presenilin 1 mutations causing Alzheimer's Disease

DEFF Research Database (Denmark)

Somavarapu, Arun Kumar; Kepp, Kasper Planeta

2016-01-01

Nearly 200 mutations in the gene coding for presenilin 1 (PSEN1) cause early-onset Alzheimer's Disease, yet the molecular mechanism remains obscure. As a meta-analysis, we compiled available clinical and biochemical data for PSEN1 variants and correlated these to chemical properties of the mutant...

Mutations in FLNB cause boomerang dysplasia.

Science.gov (United States)

Bicknell, L S; Morgan, T; Bonafé, L; Wessels, M W; Bialer, M G; Willems, P J; Cohn, D H; Krakow, D; Robertson, S P

2005-07-01

Boomerang dysplasia (BD) is a perinatal lethal osteochondrodysplasia, characterised by absence or underossification of the limb bones and vertebrae. The BD phenotype is similar to a group of disorders including atelosteogenesis I, atelosteogenesis III, and dominantly inherited Larsen syndrome that we have recently shown to be associated with mutations in FLNB, the gene encoding the actin binding cytoskeletal protein, filamin B. We report the identification of mutations in FLNB in two unrelated individuals with boomerang dysplasia. The resultant substitutions, L171R and S235P, lie within the calponin homology 2 region of the actin binding domain of filamin B and occur at sites that are evolutionarily well conserved. These findings expand the phenotypic spectrum resulting from mutations in FLNB and underline the central role this protein plays during skeletogenesis in humans.

Development of radiation-induced mutation techniques and functional genomics studies

International Nuclear Information System (INIS)

Kim, Dong Sub; Kang, Si Yong; Kim, Jin Baek

2012-01-01

This project has been performed to develop plant genetic resources using radiation (gamma-rays, ion-beam, space environments), to conduct functional genomics studies with mutant resources, and to develop new radiation plant breeding techniques using various radiation sources during 3 years. In the first section, we developed flower genetic resources, functional crop resources, and bio-industrial plant resources. In the second section, we cloned several mutated genes and studied mechanisms of gene expression and genetic diversity of mutations induced by gamma-rays. In the third section, we developed new plant breeding techniques using gamma-phytotron, heavy ion-beam, and space environments. Based on these results, a total of 8 cultivars containing Chrysanthemum, Hibiscus, kenaf, rice, and soybean were applied for plant variety protection (PVP) and a total of 4 cultivars were registered for PVP. Also, license agreement for the dwarf type Hibiscus mutant 'Ggoma' was conducted with Supro co. and the manufacturing technology for natural antioxidant pear-grape vinegar was transferred into Enzenic co. Also, 8 gene sequences, such as F3'H and LDOX genes associated with flower color in Chrysanthemum and EPSPS gene from Korean lawn grass, were registered in the database of National Center for Biotechnology Information (NCBI). In the future study, we will develop new radiation mutation breeding techniques through the mutation spectrum induced by various radiation sources, the studies for mechanism of the cellular response to radiation, and the comparative·structural·functional genomics studies for useful traits

De novo loss- or gain-of-function mutations in KCNA2 cause epileptic encephalopathy

DEFF Research Database (Denmark)

Syrbe, Steffen; Hedrich, Ulrike B S; Riesch, Erik

2015-01-01

disability, delayed speech development and sometimes ataxia. Functional studies of the two mutations associated with this phenotype showed almost complete loss of function with a dominant-negative effect. Two further individuals presented with a different and more severe epileptic encephalopathy phenotype....... They carried mutations inducing a drastic gain-of-function effect leading to permanently open channels. These results establish KCNA2 as a new gene involved in human neurodevelopmental disorders through two different mechanisms, predicting either hyperexcitability or electrical silencing of KV1.2-expressing...

Somatic mutation in larvae of the silkworm, Bombyx mori, induced by heavy ion irradiation to diapause eggs

Energy Technology Data Exchange (ETDEWEB)

Kotani, Eiji; Furusawa, Toshiharu [Kyoto Inst. of Tech. (Japan). Faculty of Textile Science; Nagaoka, Shunji [Fujita Health Univ., Toyoake, Aichi (Japan). School of Health Sciences] [and others

2002-12-01

In order to investigate whether eggs of the black-striped strain (P{sup S}) of the silkworm, Bombyx mori, represent an appropriate model for estimating the biological effect of cosmic radiation, radiosensitivity of the eggs against X-rays and heavy ion particles was examined as ground-based experiments. The exposure of diapause eggs to X-rays or heavy ion particles resulted in somatic mutations appearing as a white spot on the black integument during larval stage. Irradiation of non-diapause eggs with X-rays demonstrated a significant difference in frequency of the mutation between fractionated and single administration doses, but no difference was observed in diapause eggs. Incidence of the mutation as induced by carbon ion beams for 15-day old eggs was higher for eggs that had been kept at 15 deg C than those kept at 25 deg C. Neon beam irradiation of diapause eggs displayed dose- and linear energy transfer (LET)-dependent effects, causing a maximal rate of the mutation at 150 keV/{mu}m. These results confirm that B. mori eggs represent valid models for estimating the biological effects of cosmic radiation. (author)

Mutations in DONSON disrupt replication fork stability and cause microcephalic dwarfism.

Science.gov (United States)

Reynolds, John J; Bicknell, Louise S; Carroll, Paula; Higgs, Martin R; Shaheen, Ranad; Murray, Jennie E; Papadopoulos, Dimitrios K; Leitch, Andrea; Murina, Olga; Tarnauskaitė, Žygimantė; Wessel, Sarah R; Zlatanou, Anastasia; Vernet, Audrey; von Kriegsheim, Alex; Mottram, Rachel M A; Logan, Clare V; Bye, Hannah; Li, Yun; Brean, Alexander; Maddirevula, Sateesh; Challis, Rachel C; Skouloudaki, Kassiani; Almoisheer, Agaadir; Alsaif, Hessa S; Amar, Ariella; Prescott, Natalie J; Bober, Michael B; Duker, Angela; Faqeih, Eissa; Seidahmed, Mohammed Zain; Al Tala, Saeed; Alswaid, Abdulrahman; Ahmed, Saleem; Al-Aama, Jumana Yousuf; Altmüller, Janine; Al Balwi, Mohammed; Brady, Angela F; Chessa, Luciana; Cox, Helen; Fischetto, Rita; Heller, Raoul; Henderson, Bertram D; Hobson, Emma; Nürnberg, Peter; Percin, E Ferda; Peron, Angela; Spaccini, Luigina; Quigley, Alan J; Thakur, Seema; Wise, Carol A; Yoon, Grace; Alnemer, Maha; Tomancak, Pavel; Yigit, Gökhan; Taylor, A Malcolm R; Reijns, Martin A M; Simpson, Michael A; Cortez, David; Alkuraya, Fowzan S; Mathew, Christopher G; Jackson, Andrew P; Stewart, Grant S

2017-04-01

To ensure efficient genome duplication, cells have evolved numerous factors that promote unperturbed DNA replication and protect, repair and restart damaged forks. Here we identify downstream neighbor of SON (DONSON) as a novel fork protection factor and report biallelic DONSON mutations in 29 individuals with microcephalic dwarfism. We demonstrate that DONSON is a replisome component that stabilizes forks during genome replication. Loss of DONSON leads to severe replication-associated DNA damage arising from nucleolytic cleavage of stalled replication forks. Furthermore, ATM- and Rad3-related (ATR)-dependent signaling in response to replication stress is impaired in DONSON-deficient cells, resulting in decreased checkpoint activity and the potentiation of chromosomal instability. Hypomorphic mutations in DONSON substantially reduce DONSON protein levels and impair fork stability in cells from patients, consistent with defective DNA replication underlying the disease phenotype. In summary, we have identified mutations in DONSON as a common cause of microcephalic dwarfism and established DONSON as a critical replication fork protein required for mammalian DNA replication and genome stability.

Low-level APC mutational mosaicism is the underlying cause in a substantial fraction of unexplained colorectal adenomatous polyposis cases.

Science.gov (United States)

Spier, Isabel; Drichel, Dmitriy; Kerick, Martin; Kirfel, Jutta; Horpaopan, Sukanya; Laner, Andreas; Holzapfel, Stefanie; Peters, Sophia; Adam, Ronja; Zhao, Bixiao; Becker, Tim; Lifton, Richard P; Perner, Sven; Hoffmann, Per; Kristiansen, Glen; Timmermann, Bernd; Nöthen, Markus M; Holinski-Feder, Elke; Schweiger, Michal R; Aretz, Stefan

2016-03-01

In 30-50% of patients with colorectal adenomatous polyposis, no germline mutation in the known genes APC, causing familial adenomatous polyposis, MUTYH, causing MUTYH-associated polyposis, or POLE or POLD1, causing polymerase-proofreading-associated polyposis can be identified, although a hereditary aetiology is likely. This study aimed to explore the impact of APC mutational mosaicism in unexplained polyposis. To comprehensively screen for somatic low-level APC mosaicism, high-coverage next-generation sequencing of the APC gene was performed using DNA from leucocytes and a total of 53 colorectal tumours from 20 unrelated patients with unexplained sporadic adenomatous polyposis. APC mosaicism was assumed if the same loss-of-function APC mutation was present in ≥ 2 anatomically separated colorectal adenomas/carcinomas per patient. All mutations were validated using diverse methods. In 25% (5/20) of patients, somatic mosaicism of a pathogenic APC mutation was identified as underlying cause of the disease. In 2/5 cases, the mosaic level in leucocyte DNA was slightly below the sensitivity threshold of Sanger sequencing; while in 3/5 cases, the allelic fraction was either very low (0.1-1%) or no mutations were detectable. The majority of mosaic mutations were located outside the somatic mutation cluster region of the gene. The present data indicate a high prevalence of pathogenic mosaic APC mutations below the detection thresholds of routine diagnostics in adenomatous polyposis, even if high-coverage sequencing of leucocyte DNA alone is taken into account. This has important implications for both routine work-up and strategies to identify new causative genes in this patient group. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Treatable childhood neuronopathy caused by mutations in riboflavin transporter RFVT2

Science.gov (United States)

Foley, A. Reghan; Menezes, Manoj P.; Pandraud, Amelie; Gonzalez, Michael A.; Al-Odaib, Ahmad; Abrams, Alexander J.; Sugano, Kumiko; Yonezawa, Atsushi; Manzur, Adnan Y.; Burns, Joshua; Hughes, Imelda; McCullagh, B. Gary; Jungbluth, Heinz; Lim, Ming J.; Lin, Jean-Pierre; Megarbane, Andre; Urtizberea, J. Andoni; Shah, Ayaz H.; Antony, Jayne; Webster, Richard; Broomfield, Alexander; Ng, Joanne; Mathew, Ann A.; O’Byrne, James J.; Forman, Eva; Scoto, Mariacristina; Prasad, Manish; O’Brien, Katherine; Olpin, Simon; Oppenheim, Marcus; Hargreaves, Iain; Land, John M.; Wang, Min X.; Carpenter, Kevin; Horvath, Rita; Straub, Volker; Lek, Monkol; Gold, Wendy; Farrell, Michael O.; Brandner, Sebastian; Phadke, Rahul; Matsubara, Kazuo; McGarvey, Michael L.; Scherer, Steven S.; Baxter, Peter S.; King, Mary D.; Clayton, Peter; Rahman, Shamima; Reilly, Mary M.; Ouvrier, Robert A.; Christodoulou, John; Züchner, Stephan; Muntoni, Francesco

2014-01-01

Childhood onset motor neuron diseases or neuronopathies are a clinically heterogeneous group of disorders. A particularly severe subgroup first described in 1894, and subsequently called Brown-Vialetto-Van Laere syndrome, is characterized by progressive pontobulbar palsy, sensorineural hearing loss and respiratory insufficiency. There has been no treatment for this progressive neurodegenerative disorder, which leads to respiratory failure and usually death during childhood. We recently reported the identification of SLC52A2, encoding riboflavin transporter RFVT2, as a new causative gene for Brown-Vialetto-Van Laere syndrome. We used both exome and Sanger sequencing to identify SLC52A2 mutations in patients presenting with cranial neuropathies and sensorimotor neuropathy with or without respiratory insufficiency. We undertook clinical, neurophysiological and biochemical characterization of patients with mutations in SLC52A2, functionally analysed the most prevalent mutations and initiated a regimen of high-dose oral riboflavin. We identified 18 patients from 13 families with compound heterozygous or homozygous mutations in SLC52A2. Affected individuals share a core phenotype of rapidly progressive axonal sensorimotor neuropathy (manifesting with sensory ataxia, severe weakness of the upper limbs and axial muscles with distinctly preserved strength of the lower limbs), hearing loss, optic atrophy and respiratory insufficiency. We demonstrate that SLC52A2 mutations cause reduced riboflavin uptake and reduced riboflavin transporter protein expression, and we report the response to high-dose oral riboflavin therapy in patients with SLC52A2 mutations, including significant and sustained clinical and biochemical improvements in two patients and preliminary clinical response data in 13 patients with associated biochemical improvements in 10 patients. The clinical and biochemical responses of this SLC52A2-specific cohort suggest that riboflavin supplementation can

Induced mutation in soybean (Glycine max L.) breeding

International Nuclear Information System (INIS)

Tulmann Neto, A.; Menten, J.O.M.; Ando, A.

1984-01-01

The induced mutation in soybean (Glycine max, L.) breeding is studied. Seed treatment with gamma-rays or methanesulfonic acid ethyl ester (EMs) is used in the following varieties: Parana, Santa Rosa, UFV-1, Foscarin 31 and IAC-8. The study to obtain resistance to the soybean bud blight virus and mutants resistant to rust was done. Early mutants are also researched. (M.A.C.) [pt

GFI1B mutation causes a bleeding disorder with abnormal platelet function.

Science.gov (United States)

Stevenson, W S; Morel-Kopp, M-C; Chen, Q; Liang, H P; Bromhead, C J; Wright, S; Turakulov, R; Ng, A P; Roberts, A W; Bahlo, M; Ward, C M

2013-11-01

GFI1B is a transcription factor important for erythropoiesis and megakaryocyte development but previously unknown to be associated with human disease. A family with a novel bleeding disorder was identified and characterized. Genetic linkage analysis and massively parallel sequencing were used to localize the mutation causing the disease phenotype on chromosome 9. Functional studies were then performed in megakaryocytic cell lines to determine the biological effects of the mutant transcript. We have identified a family with an autosomal dominant bleeding disorder associated with macrothrombocytopenia, red cell anisopoikilocytosis, and platelet dysfunction. The severity of bleeding is variable with some affected individuals experiencing spontaneous bleeding while other family members exhibit only abnormal bleeding with surgery. A single nucleotide insertion was identified in GFI1B that predicts a frameshift mutation in the fifth zinc finger DNA-binding domain. This mutation alters the transcriptional activity of the protein, resulting in a reduction in platelet α-granule content and aberrant expression of key platelet proteins. GFI1B mutation represents a novel human bleeding disorder, and the described phenotype identifies GFI1B as a critical regulator of platelet shape, number, and function. © 2013 International Society on Thrombosis and Haemostasis.

A Mayan founder mutation is a common cause of deafness in Guatemala.

Science.gov (United States)

Carranza, C; Menendez, I; Herrera, M; Castellanos, P; Amado, C; Maldonado, F; Rosales, L; Escobar, N; Guerra, M; Alvarez, D; Foster, J; Guo, S; Blanton, S H; Bademci, G; Tekin, M

2015-09-08

Over 5% of the world's population has varying degrees of hearing loss. Mutations in GJB2 are the most common cause of autosomal recessive non-syndromic hearing loss (ARNHL) in many populations. The frequency and type of mutations are influenced by ethnicity. Guatemala is a multi-ethnic country with four major populations: Maya, Ladino, Xinca, and Garifuna. To determine the mutation profile of GJB2 in a ARNHL population from Guatemala, we sequenced both exons of GJB2 in 133 unrelated families. A total of six pathogenic variants were detected. The most frequent pathogenic variant is c.131G>A (p.Trp44*) detected in 21 of 266 alleles. We show that c.131G>A is associated with a conserved haplotype in Guatemala suggesting a single founder. The majority of Mayan population lives in the west region of the country from where all c.131G>A carriers originated. Further analysis of genome-wide variation of individuals carrying the c.131G>A mutation compared with those of Native American, European, and African populations shows a close match with the Mayan population. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

MBTPS2 mutations cause defective regulated intramembrane proteolysis in X-linked osteogenesis imperfecta

Science.gov (United States)

Lindert, Uschi; Cabral, Wayne A.; Ausavarat, Surasawadee; Tongkobpetch, Siraprapa; Ludin, Katja; Barnes, Aileen M.; Yeetong, Patra; Weis, Maryann; Krabichler, Birgit; Srichomthong, Chalurmpon; Makareeva, Elena N.; Janecke, Andreas R.; Leikin, Sergey; Röthlisberger, Benno; Rohrbach, Marianne; Kennerknecht, Ingo; Eyre, David R.; Suphapeetiporn, Kanya; Giunta, Cecilia; Marini, Joan C.; Shotelersuk, Vorasuk

2016-01-01

Osteogenesis imperfecta (OI) is a collagen-related bone dysplasia. We identified an X-linked recessive form of OI caused by defects in MBTPS2, which encodes site-2 metalloprotease (S2P). MBTPS2 missense mutations in two independent kindreds with moderate/severe OI cause substitutions at highly conserved S2P residues. Mutant S2P has normal stability, but impaired functioning in regulated intramembrane proteolysis (RIP) of OASIS, ATF6 and SREBP transcription factors, consistent with decreased proband secretion of type I collagen. Further, hydroxylation of the collagen lysine residue (K87) critical for crosslinking is reduced in proband bone tissue, consistent with decreased lysyl hydroxylase 1 in proband osteoblasts. Reduced collagen crosslinks presumptively undermine bone strength. Also, proband osteoblasts have broadly defective differentiation. These mutations provide evidence that RIP plays a fundamental role in normal bone development. PMID:27380894

GRIN1 mutations cause encephalopathy with infantile-onset epilepsy, and hyperkinetic and stereotyped movement disorders.

Science.gov (United States)

Ohba, Chihiro; Shiina, Masaaki; Tohyama, Jun; Haginoya, Kazuhiro; Lerman-Sagie, Tally; Okamoto, Nobuhiko; Blumkin, Lubov; Lev, Dorit; Mukaida, Souichi; Nozaki, Fumihito; Uematsu, Mitsugu; Onuma, Akira; Kodera, Hirofumi; Nakashima, Mitsuko; Tsurusaki, Yoshinori; Miyake, Noriko; Tanaka, Fumiaki; Kato, Mitsuhiro; Ogata, Kazuhiro; Saitsu, Hirotomo; Matsumoto, Naomichi

2015-06-01

Recently, de novo mutations in GRIN1 have been identified in patients with nonsyndromic intellectual disability and epileptic encephalopathy. Whole exome sequencing (WES) analysis of patients with genetically unsolved epileptic encephalopathies identified four patients with GRIN1 mutations, allowing us to investigate the phenotypic spectrum of GRIN1 mutations. Eighty-eight patients with unclassified early onset epileptic encephalopathies (EOEEs) with an age of onset stereotypic hand movements were observed in two and three patients, respectively. All the four patients exhibited only nonspecific focal and diffuse epileptiform abnormality, and never showed suppression-burst or hypsarrhythmia during infancy. A de novo mosaic mutation (c.1923G>A) with a mutant allele frequency of 16% (in DNA of blood leukocytes) was detected in one patient. Three mutations were located in the transmembrane domain (3/4, 75%), and one in the extracellular loop near transmembrane helix 1. All the mutations were predicted to impair the function of the NMDA receptor. Clinical features of de novo GRIN1 mutations include infantile involuntary movements, seizures, and hand stereotypies, suggesting that GRIN1 mutations cause encephalopathy resulting in seizures and movement disorders. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Induction of somatic mutations by low-dose X-rays: the challenge in recognizing radiation-induced events.

Science.gov (United States)

Nagashima, Haruki; Shiraishi, Kumiko; Ohkawa, Saori; Sakamoto, Yuki; Komatsu, Kenshi; Matsuura, Shinya; Tachibana, Akira; Tauchi, Hiroshi

2017-10-19

It is difficult to distinguish radiation-induced events from spontaneous events during induction of stochastic effects, especially in the case of low-dose or low-dose-rate exposures. By using a hypersensitive system for detecting somatic mutations at the HPRT1 locus, we investigated the frequency and spectrum of mutations induced by low-dose X-rays. The mutant frequencies induced by doses of >0.15 Gy were statistically significant when compared with the spontaneous frequency, and a clear dose dependency was also observed for mutant frequencies at doses of >0.15 Gy. In contrast, mutant frequencies at doses of 0.2 Gy. Our observations suggest that there could be a critical dose for mutation induction at between 0.1 Gy and 0.2 Gy, where mutagenic events are induced by multiple DNA double-strand breaks (DSBs). These observations also suggest that low-dose radiation delivered at doses of <0.1 Gy may not result in DSB-induced mutations but may enhance spontaneous mutagenesis events. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Genetic and molecular analyses of UV radiation-induced mutations in the fem-3 gene of Caenorhabditis elegans

Energy Technology Data Exchange (ETDEWEB)

Hartman, P S; De Wilde, D; Dwarakanath, V N [Texas Christian Univ., Fort Worth, TX (United States). Dept. of Biology

1995-06-01

The utility of a new target gene (fem-3) is described for investigating the molecular nature of mutagenesis in the nematode Caenorhabditis elegans. As a principal attribute, this system allows for the selection, maintenance and molecular analysis of any type of mutation that disrupts the gene, including deletions. In this study, 86 mutant strains were isolated, of which 79 proved to have mutations in fem-3. Twenty of these originally tested as homozygous inviable. Homozygous inviability was expected, as Stewart and coworkers had previously observed that, unlike in other organisms, most UV radiation-induced mutations in C. elegans are chromosomal rearrangements of deficiencies (Mutat. Res 249, 37-54, 1991). However, additional data, including Southern blot analyses on 49 of the strains, indicated that most of the UV radiation-induced fem-3 mutations were not deficiencies, as originally inferred from their homozygous inviability. Instead, the lethals were most likely ``coincident mutations`` in linked, essential genes that were concomitantly induced. As such, they were lost owing to genetic recombination during stock maintenance. As in mammalian cells, yeast and bacteria, the frequency of coincident mutations was much higher than would be predicted by chance. (Author).