WorldWideScience

Sample records for beta-globin mutation induced

  1. Targeted correction of a thalassemia-associated beta-globin mutation induced by pseudo-complementary peptide nucleic acids

    DEFF Research Database (Denmark)

    Lonkar, Pallavi; Kim, Ki-Hyun; Kuan, Jean Y;

    2009-01-01

    Beta-thalassemia is a genetic disorder caused by mutations in the beta-globin gene. Triplex-forming oligonucleotides and triplex-forming peptide nucleic acids (PNAs) have been shown to stimulate recombination in mammalian cells via site-specific binding and creation of altered helical structures...... that provoke DNA repair. However, the use of these molecules for gene targeting requires homopurine tracts to facilitate triple helix formation. Alternatively, to achieve binding to mixed-sequence target sites for the induced gene correction, we have used pseudo-complementary PNAs (pcPNAs). Due to...

  2. Nonsense mutations in the human beta-globin gene affect mRNA metabolism.

    OpenAIRE

    Baserga, S J; Benz, E J

    1988-01-01

    A number of premature translation termination mutations (nonsense mutations) have been described in the human alpha- and beta-globin genes. Studies on mRNA isolated from patients with beta zero-thalassemia have shown that for both the beta-17 and the beta-39 mutations less than normal levels of beta-globin mRNA accumulate in peripheral blood cells. (The codon at which the mutation occurs designates the name of the mutation; there are 146 codons in human beta-globin mRNA.) In vitro studies usi...

  3. Detection of Rare Beta Globin Gene Mutations in Northwestern Iran

    Directory of Open Access Journals (Sweden)

    M Haghi

    2007-04-01

    Full Text Available Introduction: Recent molecular studies on Iranian β-thalassemia genes revealed the presence of eight common mutations associated with thalassemia. Although these mutations are frequent, there are other rare and unknown mutations that can create large problems in designing preventive programs. We detected and explained the common mutations in north-western Iran previously and detection of the rare and unknown mutations could be useful in diagnosis and design of future preventive programs. Methods: In this study, 5ml peripheral blood from 20 Azari- β-thalassemia patients whose mutation was not revealed in the previous study was collected and DNA extraction was done by isopropanol and proteinase k method. Initially, samples were examined for the rare mutations: Codon6, Codon16, Codon41/42, Codon36/37, -88 and Codon22 by ARMS – PCR techniques and then the unknown cases were directly sequenced. Results: According to our results, Codon15(TGG-TGA, Codon16(-C, Codon36/37(-T, IVSII-848(C-A, IVSII-745(C-G, -28(A-C( and Codon25/26(+T were recognized and added to the spectrom of beta globin gene mutations in Azerbaijan and Iran. Also, we detected four SNP sites: 5’UTR+20(C-T, Codon2 (CAC-CAT , IVSII-16(C-G and IVSII-666(T-C in β-thalassemia genes. Conclusion: Our results could be useful for developing molecular screening plans and help prenatal diagnosis of beta thalassemia in Azerbaijan , Iran and other neighboring countries.

  4. Correction of a splice-site mutation in the beta-globin gene stimulated by triplex-forming peptide nucleic acids.

    Science.gov (United States)

    Chin, Joanna Y; Kuan, Jean Y; Lonkar, Pallavi S; Krause, Diane S; Seidman, Michael M; Peterson, Kenneth R; Nielsen, Peter E; Kole, Ryszard; Glazer, Peter M

    2008-09-01

    Splice-site mutations in the beta-globin gene can lead to aberrant transcripts and decreased functional beta-globin, causing beta-thalassemia. Triplex-forming DNA oligonucleotides (TFOs) and peptide nucleic acids (PNAs) have been shown to stimulate recombination in reporter gene loci in mammalian cells via site-specific binding and creation of altered helical structures that provoke DNA repair. We have designed a series of triplex-forming PNAs that can specifically bind to sequences in the human beta-globin gene. We demonstrate here that these PNAs, when cotransfected with recombinatory donor DNA fragments, can promote single base-pair modification at the start of the second intron of the beta-globin gene, the site of a common thalassemia-associated mutation. This single base pair change was detected by the restoration of proper splicing of transcripts produced from a green fluorescent protein-beta-globin fusion gene. The ability of these PNAs to induce recombination was dependent on dose, sequence, cell-cycle stage, and the presence of a homologous donor DNA molecule. Enhanced recombination, with frequencies up to 0.4%, was observed with use of the lysomotropic agent chloroquine. Finally, we demonstrate that these PNAs were effective in stimulating the modification of the endogenous beta-globin locus in human cells, including primary hematopoietic progenitor cells. This work suggests that PNAs can be effective tools to induce heritable, site-specific modification of disease-related genes in human cells. PMID:18757759

  5. Detection of Rare Beta Globin Gene Mutations in Northwestern Iran

    OpenAIRE

    M Haghi; N Pouladi; AA Hosseinpour Feizi; MA Hosseinpour Feizi; P Azarfam

    2007-01-01

    Introduction: Recent molecular studies on Iranian β-thalassemia genes revealed the presence of eight common mutations associated with thalassemia. Although these mutations are frequent, there are other rare and unknown mutations that can create large problems in designing preventive programs. We detected and explained the common mutations in north-western Iran previously and detection of the rare and unknown mutations could be useful in diagnosis and design of future preventive programs. Meth...

  6. Unexpected pattern of beta-globin mutations in beta-thalassaemia patients from northern Portugal

    OpenAIRE

    Cabeda, J.; Correia, C.; Estevinho, A.; Simões, C.; Amorim, M; L. Pinho; Justiça, B

    1999-01-01

    We characterized the genetic nature of beta-thalassaemia in northern Portugal. Of the 164 patients studied three were beta-thalassaemia major cases (one IVS-1-6/beta degrees 39 and two homozygous IVS-1-110). The analysis of the frequency of each mutation in the families revealed that the codon 6(-A) mutation was unexpectedly frequent (40%) and associated with the beta-globin haplotype E, and not with the usual European and North African CD6(-A) haplotypes. In contrast, the frequency of IVS-1-...

  7. Analysis of beta-globin mutations shows stable mixed chimerism in patients with thalassemia after bone marrow transplantation.

    Science.gov (United States)

    Kapelushnik, J; Or, R; Filon, D; Nagler, A; Cividalli, G; Aker, M; Naparstek, E; Slavin, S; Oppenheim, A

    1995-10-15

    Beta-thalassemia major (TM) is caused by any of approximately 150 mutations within the beta-globin gene. To establish the degree of chimerism after bone marrow transplantation (BMT), we have performed molecular analysis of beta-globin mutations in 14 patients with TM over a period of 10 years. All patients underwent T cell-depleted allogeneic BMT from HLA-identical related donors, using either in vitro T-cell depletion with CAMPATH 1M and complement or in vivo depletion using CAMPATH 1G in the bone marrow collection bag. To date, at different time periods after BMT, seven patients have some degree of chimerism; six of these patients, all blood transfusion-independent, have donor cells in the range of 70% to 95%, with stable mixed chimerism (MC). The seventh patient has less than 10% donor cells with, surprisingly, only minimal transfusion requirements. The detection of beta-globin gene point mutation, as used here, is a highly specific and sensitive marker for engraftment and MC in patients with thalassemia. In light of its specificity, the method is applicable in all cases of TM, as it is independent of sex and other non-globin-related DNA markers. The high incidence of MC found in our patients may be a consequence of the pre-BMT T-cell depletion. Because MC was associated with transfusion independence, complete eradication of residual host cells for effective treatment of TM and possibly other genetic diseases may prove not to be essential. PMID:7579421

  8. Correction of a splice-site mutation in the beta-globin gene stimulated by triplex-forming peptide nucleic acids

    DEFF Research Database (Denmark)

    Chin, Joanna Y; Kuan, Jean Y; Lonkar, Pallavi S;

    2008-01-01

    Splice-site mutations in the beta-globin gene can lead to aberrant transcripts and decreased functional beta-globin, causing beta-thalassemia. Triplex-forming DNA oligonucleotides (TFOs) and peptide nucleic acids (PNAs) have been shown to stimulate recombination in reporter gene loci in mammalian...... DNA fragments, can promote single base-pair modification at the start of the second intron of the beta-globin gene, the site of a common thalassemia-associated mutation. This single base pair change was detected by the restoration of proper splicing of transcripts produced from a green fluorescent...... cells via site-specific binding and creation of altered helical structures that provoke DNA repair. We have designed a series of triplex-forming PNAs that can specifically bind to sequences in the human beta-globin gene. We demonstrate here that these PNAs, when cotransfected with recombinatory donor...

  9. Correction of a splice-site mutation in the beta-globin gene stimulated by triplex-forming peptide nucleic acids

    OpenAIRE

    Chin, Joanna Y; Kuan, Jean Y.; Lonkar, Pallavi S.; Krause, Diane S.; Seidman, Michael M.; Peterson, Kenneth R.; Nielsen, Peter E.; Kole, Ryszard; Glazer, Peter M.

    2008-01-01

    Splice-site mutations in the beta-globin gene can lead to aberrant transcripts and decreased functional beta-globin, causing beta-thalassemia. Triplex-forming DNA oligonucleotides (TFOs) and peptide nucleic acids (PNAs) have been shown to stimulate recombination in reporter gene loci in mammalian cells via site-specific binding and creation of altered helical structures that provoke DNA repair. We have designed a series of triplex-forming PNAs that can specifically bind to sequences in the hu...

  10. the characterization of exon-1 mutation(s) of beta globin gene in beta thalassemia

    International Nuclear Information System (INIS)

    β-thalassemia constitutes one of the most serious health problems worldwide, it is the most common chronic hemolytic anemia in egypt. the aim of this work is to study the mutations of exon-1 of β-globin gene in β-thalassaemic children in sharkia governorate. the present study was included 25 healthy children and 50 patients diagnosed as β-thalassemia. this work showed that the thalassaemic patients had significantly decrease in Hb conc . than the control group (p 2 showed a significant increase as compared with the control group

  11. Characterisation of beta-globin gene mutations in Malaysian children: a strategy for the control of beta-thalassaemia in a developing country.

    Science.gov (United States)

    Thong, Meow-Keong; Tan, J A M A; Tan, K L; Yap, S F

    2005-12-01

    beta-thalassaemia major, an autosomal recessive hemoglobinopathy, is one of the most common single gene disorders in multi-racial Malaysia. The control of beta-thalassaemia major requires a multi-disciplinary approach that includes population screening, genetic counselling, prenatal diagnosis and the option of termination of affected pregnancies. To achieve this objective, the molecular characterisation of the spectrum of beta-globin gene mutations in each of the affected ethnic groups is required. We studied 88 consecutive unrelated individuals and their respective families with beta-thalassaemia (74 beta-thalassaemia major, 12 HbE-beta-thalassaemia, 2 with HbE homozygotes) and four individuals with beta-thalassaemia trait that contributed a total 180 alleles for study. Using a 2-step molecular diagnostic strategy consisting of amplification refractory mutation system (ARMS) to identify the 8 most common mutations followed by other DNA-based diagnostic techniques, a total of 177 (98.3 per cent) of the 180 beta-thalassaemia alleles were characterised. One out of 91 (1 per cent) of the Chinese alleles, one out of 46 (2.2 per cent) Malay alleles and one out of two Indian alleles remained unknown. A 100 per cent success rate was achieved in studying the Kadazandusun community in this study. A strategy to identify beta-globin gene mutations in Malaysians with beta-thalassaemia is proposed based on this outcome. PMID:15967770

  12. Familial Polycythemia Caused by a Novel Mutation in the Beta Globin Gene: Essential Role of P50 in Evaluation of Familial Polycythemia

    Directory of Open Access Journals (Sweden)

    Neeraj Agarwal, Mariluz P. Mojica-Henshaw, Elizabeth. D. Simmons, Dottie Hussey, Ching N. Ou, Josef T. Prchal

    2007-01-01

    Full Text Available Two polycythemic subjects from a family with multiple polycythemic subjects were evaluated. Estimation of oxygen affinity of Hb from venous blood gas parameters (P50 revealed low P50 suggesting a high affinity Hb variant. Further work up, which included beta globin gene sequencing, revealed a novel mutation changing a codon to the previously reported high affinity Hb - Hb Johnstown (beta109 Val->Leu. Polycythemic subjects with high affinity Hb variant are asymptomatic with normal life expectancy. Their differentiation from polycythemia vera (PV is crucial to avoid therapy which is otherwise reserved for PV patients. We provide an electronic version (in Microsoft excel program of a previously reported mathematical formula for rapid calculation of P50 from venous blood gases. Estimation of P50 is an essential initial step in the evaluation of a subject with personal and family history of polycythemia.

  13. Development of a High-Resolution Melting Approach for Scanning Beta Globin Gene Point Mutations in the Greek and Other Mediterranean Populations

    Science.gov (United States)

    Chassanidis, Christos; Boutou, Effrossyni; Voskaridou, Ersi; Balassopoulou, Angeliki

    2016-01-01

    Beta-thalassaemia is one of the most common autosomal recessive disorders worldwide. The disease’s high incidence, which is observed in the broader Mediterranean area has led to the establishment of molecular diagnostics’ assays to prevent affected births. Therefore, the development of a reliable, cost-effective and rapid scanning method for β globin gene point mutations, easily adapted to a routine laboratory, is absolutely essential. Here, we describe, for the first time, the development of a High-Resolution Melting Analysis (HRMA) approach, suitable for scanning the particularly heterogeneous beta globin gene mutations present in the Greek population, and thus adaptable to the Mediterranean and other areas where these mutations have been identified. Within this context, β globin gene regions containing mutations frequently identified in the Greek population were divided in ten overlapping amplicons. Our reactions’ setup allowed for the simultaneous amplification of multiple primer sets and partial multiplexing, thereby resulting in significant reduction of the experimental time. DNA samples from β-thalassaemia patients/carriers with defined genotypes were tested. Distinct genotypes displayed distinguishable melting curves, enabling accurate detection of mutations. The described HRMA can be adapted to a high-throughput level. It represents a rapid, simple, cost-effective, reliable, highly feasible and sensitive method for β-thalassaemia gene scanning. PMID:27351925

  14. Structural analysis of the 5 prime flanking region of the. beta. -globin gene in African sickle cell anemia patients: Further evidence for three origins of the sickle cell mutation in Africa

    Energy Technology Data Exchange (ETDEWEB)

    Chebloune, Y.; Pagnier, J.; Trabuchet, G.; Faure, C.; Verdier, G.; Labie, D.; Nigon, V. (Universite Claude Bernard-Lyon, Villeurbane (France))

    1988-06-01

    Haplotype analysis of the {beta}-globin gene cluster shows two regions of DNA characterized by nonrandom association of restriction site polymorphisms. These regions are separated by a variable segment containing the repeated sequences (ATTTT){sub n} and (AT){sub x}T{sub y}, which might be involved in recombinational events. Studies of haplotypes linked to the sickle cell gene in Africa provide strong argument for three origins of the mutation: Benin, Senegal, and the Central African Republic. The structure of the variable segment in the three African populations was studied by S1 nuclease mapping of genomic DNA, which allows a comparison of several samples. A 1080-base-pair DNA segment was sequenced for one sample from each population. S1 nuclease mapping confirmed the homogeneity of each population with regard to both (ATTTT){sub n} and (AT){sub x}T{sub y} repeats. The authors found three additional structures for (AT){sub x}T{sub y} correlating with the geographic origin of the patients. Ten other nucleotide positions, 5{prime} and 3{prime} to the (AT){sub x}T{sub y} copies, were found to be variable when compared to homologous sequences from human and monkey DNAs. These results allow us to propose an evolutionary scheme for the polymorphisms in the 5{prime} flanking region of the {beta}-globin gene. The results strongly support the hypothesis of three origins for the sickle mutation in Africa.

  15. Beta-globin gene haplotypes among cameroonians and review of the global distribution: is there a case for a single sickle mutation origin in Africa?

    Science.gov (United States)

    Bitoungui, Valentina J Ngo; Pule, Gift D; Hanchard, Neil; Ngogang, Jeanne; Wonkam, Ambroise

    2015-03-01

    Studies of hemoglobin S haplotypes in African subpopulations have potential implications for patient care and our understanding of genetic factors that have shaped the prevalence of sickle cell disease (SCD). We evaluated HBB gene cluster haplotypes in SCD patients from Cameroon, and reviewed the literature for a global distribution. We reviewed medical records to obtain pertinent socio-demographic and clinical features for 610 Cameroonian SCD patients, including hemoglobin electrophoresis and full blood counts. RFLP-PCR was used to determine the HBB gene haplotype on 1082 chromosomes. A systematic review of the current literature was undertaken to catalogue HBB haplotype frequencies in SCD populations around the world. Benin (74%; n = 799) and Cameroon (19%; n = 207) were the most prevalent haplotypes observed among Cameroonian patients. There was no significant association between HBB haplotypes and clinical life events, anthropometric measures, hematological parameters, or fetal hemoglobin (HbF) levels. The literature review of the global haplotype distributions was consistent with known historical migrations of the people of Africa. Previously reported data from Sudan showed a distinctly unusual pattern; all four classical haplotypes were reported, with an exceptionally high proportion of the Senegal, Cameroon, and atypical haplotypes. We did not observe any significant associations between HBB haplotype and SCD disease course in this cohort. Taken together, the data from Cameroon and from the wider literature suggest that a careful reassessment of African HBB haplotypes may shed further light on the evolutionary dynamics of the sickle allele, which could suggest a single origin of the sickle mutation. PMID:25748438

  16. Characterization of a large deletion in the {beta}-globin gene cluster in a newborn with hemoglobin FE

    Energy Technology Data Exchange (ETDEWEB)

    Louie, E.; Dietz, L.; Shafer, F. [Children`s Hosptial, Oakland, CA (United States)] [and others

    1994-09-01

    A sample on a newborn with hemoglobin FE screen results was obtained to investigate whether E/E or B/{beta}{degrees} thalassemia was present using polymerase chain reaction (PCR) methodology. The newborn appeared homozygous for the hemoglobin E mutation in our initial study, but the parents` genotypes did not support this diagnosis. The father is homozygous for the absence of the hemoglobin E mutation (non E/non E) and the mother is heterozygous (E/non E) for this mutation. The limitation of PCR analysis is an assumption that the amplification of the two {beta}-globin alleles is equivalent. A large deletion on one {beta}-globin gene, which would produce E/{beta}{degrees} thalassemia, would be missed if it included part or the entire region subjected to amplification. The family results were consistent with either non-paternity, sample mix-up or such a deletion of the {beta}-globin gene in the father and child. To rule out the possibility of non-paternity, two polymorphic loci (HLA on chromosome 6 and a VNTR system of chromosome 17) that are outside of the {beta}-globin gene were analyzed and show that inheritance is consistent and the likelihood of a sample mix-up is then reduced. We therefore believe there is a gene deletion in this family. At the present time, analyses of the RFLPs that are 5{prime} of the {beta}-globin gene cluster show that the polymorphisms most distal from the 5{prime} {beta}-globin gene are not being inherited as expected. These results support our interpretation that a deletion exists in the father and was inherited by the child. The father`s clinical picture of possible HPFH (the father has 12% hemoglobin F) also supports the interpretation of a deletion in this family. Deletions of the {beta}-globin gene within this ethnic group are rare. Currently, Southern blots on the family are being probed to determine the extent of the putative deletion.

  17. Polymorphism and divergence in the beta-globin replication origin initiation region.

    Science.gov (United States)

    Fullerton, S M; Bond, J; Schneider, J A; Hamilton, B; Harding, R M; Boyce, A J; Clegg, J B

    2000-01-01

    DNA sequence polymorphism and divergence was examined in the vicinity of the human beta-globin gene cluster origin of replication initiation region (IR), a 1.3-kb genomic region located immediately 5' of the adult-expressed beta-globin gene. DNA sequence variation in the replication origin IR and 5 kb of flanking DNA was surveyed in samples drawn from two populations, one African (from the Gambia, West Africa) and the other European (from Oxford, England). In these samples, levels of nucleotide and length polymorphism in the IR were found to be more than two times as high as adjacent non-IR-associated regions (estimates of per-nucleotide heterozygosity were 0.30% and 0.12%, respectively). Most polymorphic positions identified in the origin IR fall within or just adjacent to a 52-bp alternating purine-pyrimidine ((RY)n) sequence repeat. Within- and between-populations divergence is highest in this portion of the IR, and interspecific divergence in the same region, determined by comparison with an orthologous sequence from the chimpanzee, is also pronounced. Higher levels of diversity in this subregion are not, however, primarily attributable to slippage-mediated repeat unit changes, as nucleotide substitution contributes disproportionately to allelic heterogeneity. An estimate of helical stability in the sequenced region suggests that the hypervariable (RY)n constitutes the major DNA unwinding element (DUE) of the replication origin IR, the location at which the DNA duplex first unwinds and new strand synthesis begins. These findings suggest that the beta-globin IR experiences a higher underlying rate of neutral mutation than do adjacent genomic regions and that enzyme fidelity associated with the initiation of DNA replication at this origin may be compromised. The significance of these findings for our understanding of eukaryotic replication origin biology is discussed. PMID:10666717

  18. Assessment of high resolution melt analysis feasibility for evaluation of beta-globin gene mutations as a reproducible, cost-efficient and fast alternative to the present conventional method

    Science.gov (United States)

    Ramezanzadeh, Mahboubeh; Salehi, Mansour; Salehi, Rasoul

    2016-01-01

    Background: Beta-thalassemia is the most prevalent monogenic disease throughout the world. It was the first genetic disorder nominated for nation-wide prevention programs involving population screening for heterozygotes and prenatal diagnosis (PND) in Iran. Due to the high prevalence of beta-thalassemia, the shift from conventional mutation detection methods to more recently developed techniques based on novel innovative technologies are essential. We aimed to develop a real-time polymerase chain reaction (PCR) based protocol using high resolution melting (HRM) analysis for diagnosis of common beta-thalassemia mutations. Materials and Methods: Forty DNA samples extracted from peripheral blood of suspected beta-thalassemia carriers participated in this study were subjected to amplification refractory mutation system (ARMS). We then used 20 of these samples for HRM optimization. When 100% sensitivity and specificity was obtained with HRM procedure, we applied the technique for mutation detection on another remaining 20 samples as thalassemia cases with unknown mutations (detected mutations with ARMS-PCR kept confidential). Finally, the HRM procedure applied on 2 chorionic villous sample (CVS) biopsied from 12 weeks gestational age pregnant women for routine PND analysis. Results: In the first step of study, Fr 8/9 (+G), IVSI-1 (G > A), IVSI-5 (G > C), IVSI-110 (G > A), and CD44 (−C) mutations were diagnosed in samples under study using ARMS-PCR technique. Finally, the HRM procedure applied on 20 unknown samples and 2 CVS The results of HRM were in complete concordance with ARMS and confirmed by sequencing. Conclusions: The advantages of HRM analysis over conventional methods is high throughput, rapid, accurate, cost-effective, and reproducible. PMID:27169102

  19. First Spanish case of thalassemia major due to a compound heterozygosity for the IVS-II-848 (C --> A) and codon 39 (C --> T) mutations of the beta-globin gene.

    Science.gov (United States)

    Ropero, Paloma; Villegas, Ana; Muñoz, Juan; Briceño, Olga; Mora, Asunción; Salvador, María; Polo, Marta; González, Fernando A

    2006-01-01

    This report describes the first case in Spain of a severe form of beta-thalassemia (thal) due to a compound heterozygosity for the IVS-II-848 (C --> A) and the nonsense codon 39 (C --> T) mutations. Five members of a family from Cadiz (southern Spain) were studied. The proband was an 8-year-old girl diagnosed as anemic at the age of 13 months. Her father had the codon 39 (C --> T) mutation and her mother the C --> A change at nucleotide (nt) 848 of IVS-II. Haplotype analysis showed that the proband was a compound heterozygote for haplotypes I [+ --> + +] and VII [+ --> +]. This is the first description in Spain of the IVS-II-848 (C --> A) mutation. It appears, from restriction fragment length polymorphism (RFLP) analysis, that this mutation has a different origin in the various populations, where it was found. This observation shows that in this case the association of a beta(0)- and a beta(+)-thal mutation does not lead to a thalassemia intermedia but to a severe thalassemia with very low hemoglobin (Hb) levels. From a therapeutic point of view, early introduction of a transfusion regimen may improve the clinical picture of these children, allowing for better development and growth. PMID:16540410

  20. Allele-specific enzymatic amplification of. beta. -globin genomic DNA for diagnosis of sickle cell anemia

    Energy Technology Data Exchange (ETDEWEB)

    Wu, D.Y.; Ugozzoli, L.; Pal, B.K.; Wallace, B. (Beckman Research Institute of the City of Hope, Duarte, CA (USA))

    1989-04-01

    A rapid nonradioactive approach to the diagnosis of sickle cell anemia is described based on an allele-specific polymerase chain reaction (ASPCR). This method allows direct detection of the normal or the sickle cell {beta}-globin allele in genomic DNA without additional steps of probe hybridization, ligation, or restriction enzyme cleavage. Two allele-specific oligonucleotide primers, one specific for the sickle cell allele and one specific for the normal allele, together with another primer complementary to both alleles were used in the polymerase chain reaction with genomic DNA templates. The allele-specific primers differed from each other in their terminal 3{prime} nucleotide. Under the proper annealing temperature and polymerase chain reaction conditions, these primers only directed amplification on their complementary allele. In a single blind study of DNA samples from 12 individuals, this method correctly and unambiguously allowed for the determination of the genotypes with no false negatives or positives. If ASPCR is able to discriminate all allelic variation (both transition and transversion mutations), this method has the potential to be a powerful approach for genetic disease diagnosis, carrier screening, HLA typing, human gene mapping, forensics, and paternity testing.

  1. The beta-globin domain in immature chicken erythrocytes: enhanced solubility is coincident with histone hyperacetylation.

    OpenAIRE

    Nelson, D. A.; Ferris, R C; Zhang, D E; Ferenz, C R

    1986-01-01

    A 60 minute exposure of chicken immature erythrocytes to n-butyrate shifts actively acetylated and deacetylated histones to hypermodified forms. Micrococcal nuclease digestion of nuclei from n-butyrate treated cells and subsequent fractionation of the chromatin releases 40-45% of the adult beta-globin (beta A) nucleohistone into a soluble fraction. This is an eleven fold enrichment over the soluble chromatin from untreated cells (Ferenz and Nelson (1985) Nucleic Acids Res. 13, 1977-1995). The...

  2. Evolution of the primate beta-globin gene region: nucleotide sequence of the delta-beta-globin intergenic region of gorilla and phylogenetic relationships between African apes and man.

    Science.gov (United States)

    Perrin-Pecontal, P; Gouy, M; Nigon, V M; Trabuchet, G

    1992-01-01

    A 6.0-kb DNA fragment from Gorilla gorilla including the 5' part of the beta-globin gene and about 4.5 kb of its upstream flanking region was cloned and sequenced. The sequence was compared to the human, chimpanzee, and macaque delta-beta intergenic region. This analysis reveals four tandemly repeated sequences (RS), at the same location in the four species, showing a variable number of repeats generating both intraspecific (polymorphism) and interspecific variability. These tandem arrays delimit five regions of unique sequence called IG for intergenic. The divergence for these IG sequences is 1.85 +/- 0.22% between human and gorilla, which is not significantly different from the value estimated in the same region between chimpanzee and human (1.62 +/- 0.21%). The CpG and TpA dinucleotides are avoided. CpGs evolve faster than other sequence sites but do not confuse phylogenetic inferences by producing parallel mutations in different lineages. About 75% of CpG doublets have become TpG or CpA since the common ancestor, in agreement with the methylation/deamination pattern. Comparison of this intergenic region gives information on branching order within Hominoidea. Parsimony and distance-based methods when applied to the delta-beta intergenic region provide evidence (although not statistically significant) that human and chimpanzee are more closely related to each other than to gorilla. CpG sites are indeed rich in information by carrying substitutions along the short internal branch. Combining these results with those on the psi eta-delta intergenic region, shows in a statistically significant way that chimpanzee is the closest relative of human. PMID:1556740

  3. Beta-globin gene cluster haplotypes in Venezuelan sickle cell patients from the State of Aragua

    Directory of Open Access Journals (Sweden)

    Moreno Nancy

    2002-01-01

    Full Text Available Seven polymorphic sites in the beta-globin gene cluster were analyzed on a sample of 96 chromosomes of Venezuelan sickle cell patients from the State of Aragua. The Benin haplotype was predominant with a frequency of 0.479, followed by the Bantu haplotype (0.406; a minority of cases with other haplotypes was also identified: atypical Bantu A2 (0.042, Senegal (0.031, atypical Bantu A7 (0.021 and Saudi Arabia/Indian (0.021 haplotypes; however, the Cameroon haplotype was not identified in this study. Our results are in agreement with the historical records that establish Sudanese and Bantu origins for the African slaves brought into Venezuela.

  4. Expression of human beta-globin genes in transgenic mice: effects of a flanking metallothionein-human growth hormone fusion gene.

    OpenAIRE

    Townes, T M; Chen, H. Y.; Lingrel, J B; Palmiter, R. D.; Brinster, R. L.

    1985-01-01

    In an attempt to place a human beta-globin gene in an open chromatin domain regardless of its site of integration in the mouse genome, we microinjected into fertilized mouse eggs a construct in which the human beta-globin gene and a mouse metallothionein-human growth hormone fusion gene were juxtaposed and oriented in opposite directions. Mice that developed from injected eggs and that grew larger than normal were analyzed for human beta-globin mRNA. The globin genes were not expressed in ery...

  5. Allele-specific enzymatic amplification of beta-globin genomic DNA for diagnosis of sickle cell anemia.

    OpenAIRE

    Wu, D Y; Ugozzoli, L; B..K. Pal; Wallace, R B

    1989-01-01

    A rapid nonradioactive approach to the diagnosis of sickle cell anemia is described based on an allele-specific polymerase chain reaction (ASPCR). This method allows direct detection of the normal or the sickle cell beta-globin allele in genomic DNA without additional steps of probe hybridization, ligation, or restriction enzyme cleavage. Two allele-specific oligonucleotide primers, one specific for the sickle cell allele and one specific for the normal allele, together with another primer co...

  6. In silico mutation analysis of human beta globin gene in sickle cell disease patients

    Directory of Open Access Journals (Sweden)

    Hira Mubeen

    2016-05-01

    Conclusion: Studies suggested that there is need to maintain a primary prevention program to detect sickle cell disease at earlier stages despite having a large high risk. Preventive diagnosis and follow-up would reduce infant mortality by preventing the development of severe anemia as well as dangerous complications. In short, sickle cell disease surveillance would avert loss of life, measured as the number of years lost due to ill-health, disability or early death. [Int J Res Med Sci 2016; 4(5.000: 1673-1677

  7. Classical sickle beta-globin haplotypes exhibit a high degree of long-range haplotype similarity in African and Afro-Caribbean populations

    Directory of Open Access Journals (Sweden)

    Jallow Muminatou

    2007-08-01

    Full Text Available Abstract Background The sickle (βs mutation in the beta-globin gene (HBB occurs on five "classical" βs haplotype backgrounds in ethnic groups of African ancestry. Strong selection in favour of the βs allele – a consequence of protection from severe malarial infection afforded by heterozygotes – has been associated with a high degree of extended haplotype similarity. The relationship between classical βs haplotypes and long-range haplotype similarity may have both anthropological and clinical implications, but to date has not been explored. Here we evaluate the haplotype similarity of classical βs haplotypes over 400 kb in population samples from Jamaica, The Gambia, and among the Yoruba of Nigeria (Hapmap YRI. Results The most common βs sub-haplotype among Jamaicans and the Yoruba was the Benin haplotype, while in The Gambia the Senegal haplotype was observed most commonly. Both subtypes exhibited a high degree of long-range haplotype similarity extending across approximately 400 kb in all three populations. This long-range similarity was significantly greater than that seen for other haplotypes sampled in these populations (P s mutation. Conclusion Two different classical βs haplotypes, sampled from different populations, exhibit comparable and extensive long-range haplotype similarity and strong LD. This LD extends across the adjacent recombination hotspot, and is discernable at distances in excess of 400 kb. Although the multi-centric geographic distribution of βs haplotypes indicates strong subdivision among early Holocene sub-Saharan populations, we find no evidence that selective pressures imposed by falciparum malaria varied in intensity or timing between these subpopulations. Our observations also suggest that cis-acting loci, which may influence outcomes in sickle cell disease, could lie considerable distances away from β-globin.

  8. Induced mutations in citrus

    International Nuclear Information System (INIS)

    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)

  9. Induced skeletal mutations

    International Nuclear Information System (INIS)

    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

  10. Frequency and origin of haplotypes associated with the beta-globin gene cluster in individuals with trait and sickle cell anemia in the Atlantic and Pacific coastal regions of Colombia

    Directory of Open Access Journals (Sweden)

    Cristian Fong

    2013-01-01

    Full Text Available Sickle cell anemia is a genetic disease with high prevalence in people of African descent. There are five typical haplotypes associated with this disease and the haplotypes associated with the beta-globin gene cluster have been used to establish the origin of African-descendant people in America. In this work, we determined the frequency and the origin of haplotypes associated with hemoglobin S in a sample of individuals with sickle cell anemia (HbSS and sickle cell hemoglobin trait (HbAS in coastal regions of Colombia. Blood samples from 71 HbAS and 79 HbSS individuals were obtained. Haplotypes were determined based on the presence of variable restriction sites within the β-globin gene cluster. On the Pacific coast of Colombia the most frequent haplotype was Benin, while on the Atlantic coast Bantu was marginally higher than Benin. Eight atypical haplotypes were observed on both coasts, being more diverse in the Atlantic than in the Pacific region. These results suggest a differential settlement of the coasts, dependent on where slaves were brought from, either from the Gulf of Guinea or from Angola, where the haplotype distributions are similar. Atypical haplotypes probably originated from point mutations that lost or gained a restriction site and/or by recombination events.

  11. Frequency and origin of haplotypes associated with the beta-globin gene cluster in individuals with trait and sickle cell anemia in the Atlantic and Pacific coastal regions of Colombia.

    Science.gov (United States)

    Fong, Cristian; Lizarralde-Iragorri, María Alejandra; Rojas-Gallardo, Diana; Barreto, Guillermo

    2013-12-01

    Sickle cell anemia is a genetic disease with high prevalence in people of African descent. There are five typical haplotypes associated with this disease and the haplotypes associated with the beta-globin gene cluster have been used to establish the origin of African-descendant people in America. In this work, we determined the frequency and the origin of haplotypes associated with hemoglobin S in a sample of individuals with sickle cell anemia (HbSS) and sickle cell hemoglobin trait (HbAS) in coastal regions of Colombia. Blood samples from 71 HbAS and 79 HbSS individuals were obtained. Haplotypes were determined based on the presence of variable restriction sites within the β-globin gene cluster. On the Pacific coast of Colombia the most frequent haplotype was Benin, while on the Atlantic coast Bantu was marginally higher than Benin. Eight atypical haplotypes were observed on both coasts, being more diverse in the Atlantic than in the Pacific region. These results suggest a differential settlement of the coasts, dependent on where slaves were brought from, either from the Gulf of Guinea or from Angola, where the haplotype distributions are similar. Atypical haplotypes probably originated from point mutations that lost or gained a restriction site and/or by recombination events. PMID:24385850

  12. Interplay between U2 snRNP and 3' splice factor(s) for branch point selection on human beta-globin pre-mRNA.

    OpenAIRE

    Alibert, C; Tazi, J; Temsamani, J; Jeanteur, P; Brunel, C; Cathala, G

    1990-01-01

    We investigated the interaction of U2 snRNP with the branch-3' splice site region of three human beta-globin pre-mRNAs carrying nearly complete (BamHI RNA), 24 nt (Avall RNA) and 14 nt (Accl RNA) of exon 2. All supported splicing, but mRNAs yields were respectively 2 and 10 times lower for Avall and Accl RNAs than for BamHI. Analysis of RNase T1-resistant fragments immunoprecipitated by an anti-(U2)RNP antibody at early times of the splicing reaction showed that the protection encompasses bot...

  13. Splice-site mutations cause Rrp6-mediated nuclear retention of the unspliced RNAs and transcriptional down-regulation of the splicing-defective genes.

    Directory of Open Access Journals (Sweden)

    Andrea B Eberle

    Full Text Available BACKGROUND: Eukaryotic cells have developed surveillance mechanisms to prevent the expression of aberrant transcripts. An early surveillance checkpoint acts at the transcription site and prevents the release of mRNAs that carry processing defects. The exosome subunit Rrp6 is required for this checkpoint in Saccharomyces cerevisiae, but it is not known whether Rrp6 also plays a role in mRNA surveillance in higher eukaryotes. METHODOLOGY/PRINCIPAL FINDINGS: We have developed an in vivo system to study nuclear mRNA surveillance in Drosophila melanogaster. We have produced S2 cells that express a human beta-globin gene with mutated splice sites in intron 2 (mut beta-globin. The transcripts encoded by the mut beta-globin gene are normally spliced at intron 1 but retain intron 2. The levels of the mut beta-globin transcripts are much lower than those of wild type (wt ss-globin mRNAs transcribed from the same promoter. We have compared the expression of the mut and wt beta-globin genes to investigate the mechanisms that down-regulate the production of defective mRNAs. Both wt and mut beta-globin transcripts are processed at the 3', but the mut beta-globin transcripts are less efficiently cleaved than the wt transcripts. Moreover, the mut beta-globin transcripts are less efficiently released from the transcription site, as shown by FISH, and this defect is restored by depletion of Rrp6 by RNAi. Furthermore, transcription of the mut beta-globin gene is significantly impaired as revealed by ChIP experiments that measure the association of the RNA polymerase II with the transcribed genes. We have also shown that the mut beta-globin gene shows reduced levels of H3K4me3. CONCLUSIONS/SIGNIFICANCE: Our results show that there are at least two surveillance responses that operate cotranscriptionally in insect cells and probably in all metazoans. One response requires Rrp6 and results in the inefficient release of defective mRNAs from the transcription site. The

  14. Search for antisense copies of beta-globin mRNA in anemic mouse spleen

    Directory of Open Access Journals (Sweden)

    Taylor John M

    2001-03-01

    Full Text Available Abstract Background Previous studies by Volloch and coworkers have reported that during the expression of high levels of β-globin mRNA in the spleen of anemic mice, they could also detect small but significant levels of an antisense (AS globin RNA species, which they postulated might have somehow arisen by RNA-directed RNA synthesis. For two reasons we undertook to confirm and possibly extend these studies. First, previous studies in our lab have focussed on what is an unequivocal example of host RNA-directed RNA polymerase activity on the RNA genome of human hepatitis delta virus. Second, if AS globin species do exist they could in turn form double-stranded RNA species which might induce post-transcriptional gene silencing, a phenomenon somehow provoked in eukaryotic cells by AS RNA sequences. Results We reexamined critical aspects of the previous globin studies. We used intraperitoneal injections of phenylhydrazine to induce anemia in mice, as demonstrated by the appearance and ultimate disappearance of splenomegaly. While a 30-fold increase in globin mRNA was detected in the spleen, the relative amount of putative AS RNA could be no more than 0.004%. Conclusions Contrary to earlier reports, induction of a major increase in globin transcripts in the mouse spleen was not associated with a detectable level of antisense RNA to globin mRNA.

  15. Increased expression of alpha- and beta-globin mRNAs at the pituitary following exposure to estrogen during the critical period of neonatal sex differentiation in the rat

    DEFF Research Database (Denmark)

    Leffers, H; Navarro, V M; Nielsen, John E; Mayen, A; Pinilla, L; Dalgaard, M; Malagon, M M; Castaño, J P; Skakkebaek, N E; Aguilar, E; Tena-Sempere, M

    2006-01-01

    neuroendocrine system controlling development and function of the reproductive axis; the HP unit being highly sensitive to the organizing effects of endogenous and exogenous sex steroids. To gain knowledge on the molecular mode of action and potential biomarkers of exposure to estrogenic compounds at the HP unit...... was not detected at the hypothalamus, cortex, cerebellum, liver and testis. Finally, enhanced levels of alpha- and beta-globin mRNAs at the pituitary were also demonstrated after neonatal administration of the anti-androgen flutamide. In summary, alpha- and beta-globin genes may prove as sensitive...

  16. Induced mutations in castor

    International Nuclear Information System (INIS)

    Castor (Ricinus communis L.) is an important oilseed crop in India. To create variability mutations were induced in two cultivars 'TMV5' (maturing in 130-140 days) and 'CO1' (perennial type). Gamma rays and diethyl sulphate and ethidium bromide were used for seed treatment. Ten doses, from 100 to 1000 Gy were employed. For chemical mutagenesis five concentrations of mutagenes from 10 to 50 mM were tried. No economic mutants could be isolated after treatment with the chemical mutagens. The following economic mutants were identified in the dose 300 Gy of gamma rays. Annual types from perennial CO 1 castor CO 1 is a perennial variety (8-10 years) with bold seeds (100 seed weight 90 g) and high oil content (57%). Twenty-one lines were isolated with annual types (160-180 days) with high yield potential as well as bold seeds and high oil content. These mutants, identified in M3 generation were bred true in subsequent generations up to M8 generation. Critical evaluation of the mutants in yield evaluation trials is in progress

  17. Mutations induced by ultraviolet light

    International Nuclear Information System (INIS)

    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

  18. Mutations induced by ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Gerd P. [Department of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States)]. E-mail: gpfeifer@coh.org; You, Young-Hyun [Department of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States); Besaratinia, Ahmad [Department of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States)

    2005-04-01

    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

  19. Rice Breeding with Induced Mutation

    International Nuclear Information System (INIS)

    A plant breeder may utilize the genetic variability from available natural resources, he may build up variability through hybridization, he can induce variability through mutagen treatments or he may use a combination of any of the three for the improvement of crop plants. A number of improved varieties of rice have been developed through mutation breeding. It is shown, how a breeder may utilize mutation induction to achieve successfully his breeding objectives. (author)

  20. Induced mutations in sorghum improvement

    International Nuclear Information System (INIS)

    A critical review of different aspects of mutagen sensitivity, considering the importance of such factors as genotypic constitution of the material, pre- and post-treatment modifications, type of mutagen and dose, techniques of handling the material and treatment procedures to maximize the induction of mutations together with the scope of induced mutations in sorghum improvement is presented. Hydrazine was found to be a more effective and efficient mutagen for inducing chlorophyll and viable mutations in sorghum than ethyl methanesulphonate, methyl methanesulphonate or γ-rays. Ethyl methane-sulphonate among the alkylating agents and nitroso methyl urea among nitroso compounds were the most potent mutagens. The efficient radiation dose was within the 20-35 kr range whereas 0.015M was the effective dosage for hydrazine and ethylmethane sulphonate. The combination treatments of various physical and chemical mutagens failed to yield significant increase in the recovery of mutations, while cysteine post-treatments of γ-irradiated and hydrazine-treated material reduced seedling injury, seed sterility and increased the recovery of viable mutations compared to single treatments. There is scope for induced mutations in solving some of the current problems of sorghum improvement such as, increasing the recombination potential of tropical X temperate crosses, improving the nutritional quality of grain and forage sorghums, diversification of male sterile cytoplasmic sources, better understanding of mechanism of apomixis and augmenting the levels of resistance to sorghum insects, pests and diseases. (author)

  1. Plant improvement by induced mutations

    International Nuclear Information System (INIS)

    Genetic variability is required for the plant breeder to select better traits. Mutation induction by radiation and other mutagens is a means of altering genes and creating genetic variability for the breeder. A list is given of the number of mutant varieties of vegetables, fruits and ornamental flowers. Data given in the tables show that using induced mutations, 227 improved varieties of agricultural crops have been developed and released to farmers in 35 different countries. The IAEA has been involved in fostering mutation breeding since its foundation through training and direct research support. The Joint FAO/IAEA Division has published the Mutation Breeding Newsletter for plant breeders all over the world to keep abreast with developments in this field

  2. Induced mutations in sesame breeding

    International Nuclear Information System (INIS)

    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)

  3. Induced mutation of Dendrobium orchid

    International Nuclear Information System (INIS)

    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

  4. Plant domestication by induced mutation

    International Nuclear Information System (INIS)

    An Advisory Group Meeting was convened to consider possibilities and limitations of induced mutation technology for the purpose of domestication, to discuss the methodology, identify target species, and to define the character changes required. The meeting took place in Vienna at the IAEA Headquarters from 17-21 November 1986. This publication contains the review papers as well as the results of discussions in the form of conclusions and recommendations. As a supplement, a bibliography has been added. Refs, figs and tabs

  5. Identification of the multiple beta-thalassemia mutations by denaturing gradient gel electrophoresis.

    OpenAIRE

    Cai, S P; Kan, Y W

    1990-01-01

    We used denaturing gradient gel electrophoresis to detect the beta-thalassemia mutations in the Chinese population. By amplifying the beta-globin gene in four separate fragments and electrophoresing the amplified DNA in two gels, we were able to distinguish all the 12 known mutations on the basis of the mobility of the homoduplexes and heteroduplexes. We conclude that denaturing gradient gel electrophoresis offers a nonradioactive means of detecting multiple mutations in genetic disorders.

  6. Induced Mutations in Thai Rice

    International Nuclear Information System (INIS)

    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.

  7. On the origin and spread of beta-thalassemia: recurrent observation of four mutations in different ethnic groups.

    OpenAIRE

    Wong, C.; Antonarakis, S E; Goff, S C; Orkin, S H; Boehm, C. D.; Kazazian, H H

    1986-01-01

    Seven beta-thalassemia genes were characterized after they were identified as candidates for previously undescribed mutations based upon the close association of DNA polymorphism haplotypes in the beta-globin gene cluster with specific ethnic mutations. The molecular defect in four of these genes was identical, a frameshift deletion of four nucleotides (-CTTT) within codons 41 and 42. This gene represents a common Southeast Asian mutation shared by a Laotian beta-thalassemia gene, [framework ...

  8. Wheat improvement by induced mutations

    International Nuclear Information System (INIS)

    The genetic constitution of the allohexaploid Triticum aestivum offers enormous opportunities of induction and exploitation of mutations for qualitative as well as for quantitative characters. The paper presents and discusses experimental data on the evolution of Mutant 115 with reference to the improvement of grain yield and related characters. The mutant produced significantly (P >= 0.05) higher grain yield than the commercial varieties (Pak-70 and Mexi-Pak) and the mother cultivar (Nayab). In the zonal trials conducted on Government farms and farmer's fields, Mutant 115 gave 10% and 25% more yield than Pak-70 and Mexi-Pak respectively. The stability parameters of the mutant were computed. The mutant was characterized by having b > 1.0 and medium s.e. (b). The mutant exhibited resistance to Puccinia graminis tritici and Puccinia recondita. The technological properties of the mutant were at par with the existing commercial varieties. The radiation treatment also removed two original defects of the mother cultivar Nayab viz. apical sterility and red grain colour. Induced mutations can thus be exploited successfully for the improvement of contemporary wheat cultivars. (author)

  9. Rice breeding with induced mutations

    International Nuclear Information System (INIS)

    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

  10. Interplay between U2 snRNP and 3 prime splice factor(s) for branch point selection on human. beta. -globin pre-mRNA

    Energy Technology Data Exchange (ETDEWEB)

    Alibert, C.; Tazi, J.; Temsamani, J.; Jeanteur, P.; Brunel, C.; Cathala, G. (URA CNRS, Montpellier (France) Universite des Sciences et Techniques du Languedoc, Montpellier (France))

    1990-01-25

    The authors investigated the interaction of U2 snRNP with the branch-3{prime} splice rite region of three human {beta}-globin pre-mRNAs carrying nearly complete (BamHI RNA), 24 nt (AvaII RNA) and 14 nt (AccI RNA) of exon 2. All supported splicing, but mRNAs yields were respectively 2 and 10 times lower for AvaII and AccI RNAs than for BamHI. Analysis of RNase T{sub 1}-resistant fragments immunoprecipitated by an anti-(U2)RNP antibody at early times of the splicing reaction showed that the protection encompasses both the branch point region and the end of the intron in BamHI and AvaII, but essentially only the branch point in AccI RNAs. Similar experiments performed at late times with an anti-Sm antibody recognizing all snRNPs showed that the end of the intron is protected in all but BamHI RNAs. These results support the conclusion that U2 snRNP binds to a fully efficient precursor (BamHI RNA) through another factor(s) recognizing the 3{prime} splice site. Either the absence of an initial contact between U2 snRNP and the factor(s) recognizing the end of the intron (AccI RNA) or the unability of this ternary complex to undergo a conformational change (AvaII RNA) could render these severely truncated precursors poor substrates. These different situations have consequences on the branch point selection itself. BamHI and AvaII RNAs use three functional branch points at early times. Later one, all three branch points are used at the same rate in AvaII, while the usual one prevails in BamHI RNAs.

  11. Radiation-induced mutation at minisatellite loci

    International Nuclear Information System (INIS)

    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 137Cs, consistent with radiation-induction of germline mutation. The potential use of minisatellites in monitoring germline mutation in humans will be discussed

  12. Induced mutations - a tool in plant research

    International Nuclear Information System (INIS)

    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

  13. Induced mutations for crop improvement

    International Nuclear Information System (INIS)

    Mutation induction has become an established tool in plant breeding to supplement existing germ plasma and to improve cultivars in certain specific traits. Hundreds of improved varieties have been released to farmers for many different crop species, demonstrating the economic value of the technology. Limitations arise mainly from the large mutagenized populations to be screened and from the unsatisfactory selection methods. Both limitations may be eased to some extent by advances in techniques of plant in-vitro culture. (author). Refs, 1 fig., 7 tabs

  14. Radiation-induced mutations in mammals

    International Nuclear Information System (INIS)

    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

  15. Space-induced mutations for crop improvement

    International Nuclear Information System (INIS)

    The space-induced mutations and their applications to crop improvement are comprehensively reviewed. The space provides a special environment with super vacuum, microgravity and strong cosmic radiation. Experimental data showed that space environment conditions may affect plant growth and development as well as induce genetic changes of crop seeds. The frequency of chromosomal aberrations were greatly increased in seeds carried into space and later germinated on the ground. More multiple chromosomal aberrations were observed in seeds hit by cosmic radiation in space, while similar aberration increases were found in seeds not hit in flight, and the longer the seeds were kept in space, the higher the frequency of chromosomal aberrations was, implying that the combined effects of both cosmic radiation and microgravity or other space-flight factors were the main causes of genetic changes in space-flight seeds. Good achievements have been made by space-induced mutations in crop improvement, especially in sweet pepper, rice and wheat, some very useful and rare mutants which might make a great breakthrough in crop yield improvement have been obtained. It was concluded that crop space-induced mutation breeding can be an effective way in both breeding new cultivars and creating distinctive genetic resources because of its wide mutation spectrum, high frequency of useful genetic variation as well as short breeding period. (58 refs.)

  16. Induced mutations for human welfare through agriculture

    International Nuclear Information System (INIS)

    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

  17. Economic Aspects of Using Induced Mutations in Plant Breeding

    International Nuclear Information System (INIS)

    Economic aspects of mutation plant breeding are considered in relation to basic principles of mutation induction and selection, when to use mutations in plant breeding programmes and mutation breeding strategies. The following basic principles of mutation plant breeding are outlined: - A imitation is induced in a single cell and expressed in the progeny from that cell. - Expression of a mutation is influenced by its genetic nature and the breeding system of the organism. - The mutation frequency determines the number of cell progenies that have to be examined to detect a particular mutant. - Random mutations in quantitatively inherited characters generally result in an increase in variance and a shift in the mean. Mutation rates for various types of mutations have been estimated and population sizes for mutation plant breeding experiments calculated. Based upon these principles the potential for using induced mutations in plant breeding and some breeding strategies are outlined. (author)

  18. Induced mutation in tropical fruit trees

    International Nuclear Information System (INIS)

    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

  19. Ways of improving photosynthesis by induced mutation

    International Nuclear Information System (INIS)

    Three ways of increasing photosynthetic efficiency in C3 plants by induced mutation are described. In the first procedure, using the crucifer Arabidopsis thaliana as a model organism, several single recessive nuclear mutations have been recovered in enzymes of the photorespiratory pathway. These mutations render photorespiration a conditionally lethal characteristic. The mutant strains are then used to select for second-site revertants which survive the lethal conditions. Such revertants would be unable to initiate the photorespiratory pathway, and therefore possess enhanced photosynthetic activity. In a second approach, designed to determine the feasibility of altering the two activities of ribulose bisphosphate carboxylase (Rubisco), the enzyme which regulates carbon flow between photosynthesis and photorespiration, uniparental mutants of Chlamydomonas reinhardii have been recovered which possess defective Rubisco. These mutants, lacking the ability to fix CO2, cannot survive phototrophically. Phototrophic revertants are then recovered and the Rubisco enzyme is examined. A search is being made for revertants with an increased carboxylation/oxygenation ratio, indicating increased photosynthetic efficiency. Finally, unicellular algae such as C. reinhardii are able to increase the in-vivo carboxylation efficiency of Rubisco by concentrating CO2 internally. To elucidate the nature of this CO2 concentrating system, and to determine whether such a system might be incorporated into higher plant species with C3 photosynthesis, induced mutants which are not capable of concentrating CO2 have been sought. Mutants with the expected phenotype, a high CO2 growth requirement, have been recovered and partially characterized. (author)

  20. Use of induced mutations for potato improvement

    International Nuclear Information System (INIS)

    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)

  1. Gamma ray induced somatic mutations in rose

    International Nuclear Information System (INIS)

    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 M1V1, four in M1V2 and three in M1V3. 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

  2. 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)

  3. Induced mutation variability in Linum grandiflorum Desp

    International Nuclear Information System (INIS)

    Linum grandiflorum is a popular crop on the European market of ornamental plants. It is commonly used as a flowerbed crop. L. grandiflorum is known for its limited genetic variability. Up to now its colour spectrum remains poor and mutations of flower shape, which are not of small importance for any ornamental crop advancement on the consumer market, are unknown. It was supposed in this connection, that the method of chemical mutagenesis had to broaden the mutation spectrum and to increase the frequency of useful mutations in comparison with natural variability. Seeds of annual wild species of L. grandiflorum with a large ruby corolla and a dark red spot at the centre of the flower (var. rubrum) were treated with 0.01, 0.05, 0.1 and 0.5% of ethyl methanesulphonate (EMS) for 18 hours. After treatment the seeds were washed to remove the mutagen. Seeds of every M1 plant were sown separately in individual plant-to- progeny rows. In the M2 generation the majority of visually selected mutants were selfed and advanced from M2 to M3, where every mutant line was raised along with the parental genotype. The results of screening M2 segregating material indicated that L. grandiflorum was characterized by a high frequency of morphological mutations. Six types of mutants, namely chlorophyll deficiency, leaf waxy bloom, corolla colour, flower shape and size, and plant habit were selected from the M2 generation). EMS concentrations of 0.05 and 0.1% were the most optimal to induce the greatest number of mutants, taking into account the high survival rate of plants in M1. Half of the mutants were found with modified chlorophyll content and one-third had a new habit. Under 0.05 and 0.1% EMS treatments only super-dwarf plants and plants with the modified corolla colour were found. The spectrum of chlorophyll mutants isolated in the present study comprised of albina, viridis and xantha mutations. The variant super-dwarf possessed a phenotype of small (several centimetres in height only

  4. Induced mutations in vegetatively propagated plants II

    International Nuclear Information System (INIS)

    A Co-ordinated Research Programme on the Improvement of Vegetatively Propagated Crops and Tree Crops Through Induced Mutations was sponsored by the IAEA between 1972 and 1980. It was based on the recommendations of an FAO/IAEA panel of experts who met in September 1972 and concluded that mutation induction was an appropriate tool for improving genetically crop plants that are not easily improved by cross breeding. Research has been carried out to develop techniques for induction, selection and utilization of mutants in various vegetatively propagated crops. The programme has included a wide variety of plant species in tropical and temperate climates, such as sugarcane, potato, cassava, mulberry, citrus, bananas, apple, cherry, peach, grape, forage grasses, as well as a group of ornamental plants. The present book contains the reports presented by the project leaders at the final Research Co-ordination Meeting organized by the Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development, and held in Coimbatore, India, from 11-15 February, 1980. It also includes a review of the programme with conclusions and recommendations

  5. Breeding for quality rice through induced mutation

    International Nuclear Information System (INIS)

    Results of two experiments on induced mutations in rice by gamma radiation are reported. In the first experiment, F2 seeds from a cross between IR 8 and Basmati 370 were exposed to 30 and 35 k/Rads of gamma rays from a Co60 source. A number of dwarf mutants with good plant type and long slender grain were evaluated for the yield potential and quality characteristics in M4 generation, using Sona as check variety. Some of the hybrid mutants combine yield as well as good quality characteristics. In the second experiment, a locally adapted scented variety Tilakchandan, with good grain quality was treated with EMS. A number of economic dwarf mutants have been isolated in M2 generation. This offers promise for use in the hybridization programme. (author)

  6. Induced mutation for plant domestication: Lantana depressa Naud

    International Nuclear Information System (INIS)

    Lantana depressa Naud (Verbenaceae), is a semi-wild herb with creeping habit and yellow flower. It has been included in a plant domestication programme through induced mutation. Gamma rays have been successfully induced new flower colour and variegated chlorophyll mutation. The mutants can be utilised as potted ornamentals. Use of mutation breeding as an efficient technique for the domestication of L. depressa has been suggested. (author). 10 refs., 2 tabs., 4 figs

  7. A novel β-globin gene mutation HBB.c.22 G>C produces a hemoglobin variant (Hb Vellore) mimicking HbS in HPLC.

    Science.gov (United States)

    Edison, E S; Sathya, M; Rajkumar, S V; Nair, S C; Srivastava, A; Shaji, R V

    2012-10-01

    Hemoglobinopathies are highly prevalent in Indian population. DNA analysis to detect causative mutations is required for identifying rare hemoglobin variants or when hematological results are discordant with the clinical phenotype. In this report, we describe a novel hemoglobin variant caused by a mutation in beta-globin gene, Codon 7 GAG→CAG (Glu→Gln) that elutes in the position of sickle haemoglobin (HbS) in cation exchange high performance liquid chromatography. This report highlights possible diagnostic pitfalls in interpreting data solely based on haemoglobin analysis and usefulness of mutation screening in definitive diagnosis of hemoglobinopathies. PMID:22471768

  8. Genetic improvement of soybean through induced mutations

    International Nuclear Information System (INIS)

    Narrow genetic base of cultivated varieties in soybean is of global concern. Mutations, spontaneous or induced, are an important source for inducing genetic variability. Soybean cultivar VLS -2 was irradiated with 250 Gy gamma rays to induce mutations for morphological characters, high yield, high oil and low trypsin inhibitor content. A large number of mutants with altered morphological characters like plant height, flower colour, sterility, leaf shape, number of pods per plant, seed colour, early or late maturity were identified and characterized. Twenty six selections with high oil content ranging from 20 to 22 percent as compared to the parent VLS-2 (19.7 percent) were identified. Highest oil content was observed in the mutants M-387 (22.7%) and M-126 (20.7%). A modified rapid and reliable micro titration plate technique was developed and used for screening trypsin inhibitor (TI) content in the seeds of 7480 M2 plants. Three mutants namely M-213 (13.7 TIU/mg seed meal), M-104 (15.4 TIU/mg seed meal) and M-291 (15.9 TIU/mg seed meal) showed lower levels of TI content as compared to the parent VLS-2 (21.8 TIU/mg seed meal). Breeding behaviour and salient features of the mutants were studied through the M3 - M5 generations. In the M5 generation, twenty four mutants with good agronomic traits were evaluated for various quantitative characters. Analysis of variance showed highly significant variation among the mutants for yield per plant. Mutant M-17 showed high yield per plant 13.1gm in comparison to the parent VLS-2 (8.3 gm). This mutant also exhibited more number of branches, more number of pods and high harvest index. Genetic diversity study of the mutants indicated that mutant M-17 had maximum dissimilarity value of 24% from the parent and was most diverse. These identified mutants can be utilised in the breeding programme for developing elite varieties of soybean. (author)

  9. Dominant cataract mutations and specific-locus mutations in mice induced by radiation or ethylnitrosourea

    International Nuclear Information System (INIS)

    In a combined experiment, dominant cataract mutations and specific-locus mutations were scored in the same offspring. In radiation experiments, a total of 15 dominant cataract and 38 specific-locus mutations was scored in 29396 offspring. In experiments with ethylnitrosourea (ENU), a total of 12 dominant cataracts and 54 specific-locus mutations was observed in 12712 offspring. The control frequency for dominant cataracts was 0 in 9954 offspring and for specific-locus mutations 11 in 169955 offspring. The two characteristic features of radiation-induced specific-locus mutations - the augmenting effect of dose fractionation and the quantitative differences in the mutation rates between spermatogonial and post-spermatogonial stages - can also be demonstrated for the induction of dominant cataracts. The dominant cataract mutations recovered can be categorized into 7 phenotypic classes. The only noteworthy difference observed between the radiation- and ENU-induced mutations recovered was that, of the 2 radiation-induced total lens opacities, both were associated with an iris anomaly and microphthalmia whereas the ENU-induced total opacities were not. (orig./MG)

  10. Induced mutation in pearl millet (Pennisetum glaucum)

    International Nuclear Information System (INIS)

    Pearl millet (Pennisetum glacum) ranks the sixth among cereals in the world following wheat, rice, maize, barely and sorghum. More than 95% of the crop is produced in Asia and Africa, where it is mainly grown for its grain. In America and Europe, it is mainly used as fodder for animals. In this study, 20 different pearl millet genotypes, collected from all over the Sudan, with concentration on the western parts of the country, were used. These genotypes were grown, evaluated and tested for different morphological and agronomical characters. The aim of this experiment was the estimation of variability among pearl millet genotypes. A Radiosensitivity test was carried out to define the suitable level of Gamma radiation for treating pearl millet seeds. Then field performance of the mutants obtained was studied for three successive generations. In the first experiment, the results showed that the 20 pearl millet genotypes exhibited significant difference in most of the parameters studied.Only four were selected to continue with. The radiosensitivity test results reflected that the effective dose ranged between 200-400Gy for the four genotypes. The three mutant generations showed high variations. These variations were reflected in the mean and the range regarding the parameters studied. The second mutant generation (M2) had the highest number and frequency of mutations, the famous being: chlorophyll deficiency and the male sterility. The third mutant generation also had high variations between the different treatments and within the treatment itself. However, many families showed a considerable degree of homogeneity. The four pearl millet genotypes reacted differently towards the different levels of Gamma radiation. Mutation induction means proved to be a successful tool for creating variations within a crop variety and inducing desired attributes that can help in far reaching impact on agriculture. (author)

  11. Induced mutation studies in some mungbean cultivars

    International Nuclear Information System (INIS)

    The induced mutation through different gamma irradiation frequencies viz. 100, 200, 300, 400 and 500 Gy in some agronomic traits of five mungbean cultivars was studied at Research Area of Faculty of Agriculture, Gomal University, D. I Khan for consecutive three years. The results of analysis show that a wide range of variability exists in all the characters except plant height. The genotypic effect on days to flowering, days to maturity, plant height. Number of branches, Number of pods and Number of clusters ranged from 43.82 to 44.96 days, 87.60 to 91.75 days, 42.16 to 51.61 cm, 1.83 to 2.07. 16.97 to 21.46 and 4.44 to 5.56, respectively. Similarly, mutagenic effects on days to 50% flowering days for maturity, plant height, number of branches, number of pods and number of ranged from 44.05 to 45.62 days, 88.62 to 91.83 days, 47.07 to 43.43 cm. 1.62 to 2.00, 17 to 22.30 and 4.53 to 5.50 respectively. The genotype X dose interaction was highly significant for days to 50% flowering, maturity, number of branches and clusters and non-significant for plant height and number of pods

  12. Radiation-induced mutations in fish

    International Nuclear Information System (INIS)

    X-ray-induced mutations in teleostean fish were studied from the point of social behavior. A significant reduction in male aggression was found in the postirradiated F1 generation after the irradiation of parental oogonia and spermatogonia, with 2 x 500 R (24 hr apart) of x-rays, but did not alter the aggression of F1 females. A study on backcross generation of irradiated line fitted with a two-factor model of dominant genetic factors, high- and low-aggressive, which co-acted additively in repressing the male aggression. Social cohesiveness was compared between F1 convict cichlides (C. nigrofasciatum) exposed by 0, 250, 500, 750, 1000, and 2000 R of x-rays. The best response was observed in males with 500 R and in females with 750 R. While an increase in cohesiveness was observed in F1 males with 500 R, the cohesiveness of F1 females decreased with 750 and 200 R, suggesting that the increase in male was associated with a reduction of inter-male aggression. A new ''guppy male courtship activity test'' was carried out in the offsprings of irradiated guppy, maintained in seawater and in freshwater. The mean values of both the frequency and the duration of four behavioral traits of the male guppy increased in postirradiated F1 generation of the seawater substrain but were unchanged in that of freshwater's. In F2 generation the mean values of the same behavioral characters decreased in both seawater and freshwater substrains. (Nakanishi, T.)

  13. Induced mutation breeding by fast neutron

    International Nuclear Information System (INIS)

    The high-yield and long-grain new variety 'Zhongtie 31' was developed through five generations after irradiation of the rice variety 'Tieqiu 15' dried seeds by 14 MeV fast neutrons with a fluence of (1.33 ∼ 3.33) x 1011 neutrons cm-2. It matured earlier 3 to 5 days, the plant is higher 10 cm, bigger ear, more grain than its original variety 'tieqiu 15', and the yield increased by 19.2% to 30.7%. The source of new variety 'Zhongtie 31' was proved by the isoenzyme genetics. In field test, it increased by 7% to 10% as compared with high-yield variety 'Guichao No.2' and the hybrid rive 'Shanyou No.2', and is more palatable. The new variety was initiated by irradiation mutagensis routine rice, its well-grown and bumper-yield performances may be compared favourably with hybrid rice variety. In July 1986, the new variety 'Zhongtie 31' was obtained by inducing mutation with fast neutron. The same year, the planted area of 'Zhongtie 31' has achieved upto 250 thousand mu (1.67 x 108 cm2)

  14. Use of induced mutation for plant domestication

    International Nuclear Information System (INIS)

    Lantana depressa Naud belonging to the family Verbenaceae is a semi-wild herb with creeping habit and yellow flowers. It has no other genetic variability. Stem cutting were irradiated with different doses of gamma-rays and planted. Different types of radiation effects as morphological abnormalities, reduction in sprouting, plant height, leaf size and number were recorded after irradiation. Plants of 1 Krad treated V1M1 population showed chlorophyll variegation in leaves as mericlinal chimera. Plants of 1 Krad treated V1M2 population produced one branch with light yellow (canary yellow) flowers; those treated with 2 Krad produced bicoloured (yellow and white) flowers on one branch. All the three mutants have been isolated and established in pure form and named L.depressa variegata (chlorophyll variegated leaf), Niharika (canary yellow flower) and L.depressa bicoloured as new varieties. These mutants can now be grown as potted ornamentals. These results show that new desirable genotypes may be induced through mutation for domestication of wild genotypes. (author)

  15. Induced mutation in garlic (Allium sativum)

    International Nuclear Information System (INIS)

    Two strains of garlic, Ilocos White and Laguna Strain, were exposed to 500, 600, 800 and 1000 rad of gamma rays. A control was included for comparison. The garlic strains irradiated with 1000 rad did not survive. Only three treatments and the control were evaluated for yield performance in terms of bulb size in the Mu1, Mu2 and Mu3 populations. In Mu1, the bulb size of the control was greater and significantly different from those of the treated strains. In Mu2, more large bulbs of Ilocos White were obtained from 600 and 800 rad than from 500 rad and the control. In contrast, Laguna Strain had the lowest percentage large bulbs at 600 rad. The percentage selection of large and medium bulbs increased from Mu2 to Mu3 in both strains. The two garlic strains showed genetic differences in their response to gamma irradiation. In general, Laguna Strain was more responsive to induced mutation than Ilocos White; large bulbs in increased quantity were obtained from this strain. (author). 2 figs, 1 tab

  16. Acute chest syndrome is associated with single nucleotide polymorphism-defined beta globin cluster haplotype in children with sickle cell anaemia.

    Science.gov (United States)

    Bean, Christopher J; Boulet, Sheree L; Yang, Genyan; Payne, Amanda B; Ghaji, Nafisa; Pyle, Meredith E; Hooper, W Craig; Bhatnagar, Pallav; Keefer, Jeffrey; Barron-Casella, Emily A; Casella, James F; Debaun, Michael R

    2013-10-01

    Genetic diversity at the human β-globin locus has been implicated as a modifier of sickle cell anaemia (SCA) severity. However, haplotypes defined by restriction fragment length polymorphism sites across the β-globin locus have not been consistently associated with clinical phenotypes. To define the genetic structure at the β-globin locus more thoroughly, we performed high-density single nucleotide polymorphism (SNP) mapping in 820 children who were homozygous for the sickle cell mutation (HbSS). Genotyping results revealed very high linkage disequilibrium across a large region spanning the locus control region and the HBB (β-globin gene) cluster. We identified three predominant haplotypes accounting for 96% of the β(S) -carrying chromosomes in this population that could be distinguished using a minimal set of common SNPs. Consistent with previous studies, fetal haemoglobin level was significantly associated with β(S) -haplotypes. After controlling for covariates, an association was detected between haplotype and rate of hospitalization for acute chest syndrome (ACS) (incidence rate ratio 0·51, 95% confidence interval 0·29-0·89) but not incidence rate of vaso-occlusive pain or presence of silent cerebral infarct (SCI). Our results suggest that these SNP-defined β(S) -haplotypes may be associated with ACS, but not pain or SCI in a study population of children with SCA. PMID:23952145

  17. Increasing upland rice variability through induced mutations

    International Nuclear Information System (INIS)

    Upland rice cultivars in Sao Paulo State, Brazil are generally tall (120-135 cm) even under low fertility soils (''cerrado''). In areas of continuous rice cultivation soil fertility is usually restored and the plants grow leafy, lodge, and seldom yield more than 2 t/ha. A mutation breeding programme involving Instituto Agronomico (IAC), International Atomic Energy Agency (IAEA), and Centro de Energia Nuclear na Agricultura (CENA) was started with the following objectives: (1) to induce a semidwarf mutant gene in the upland cultivar IAC 165; (2) once obtained, to incorporate the semidwarf gene in the standard hybridization program; and (3) to hybridize the new semidwarf source with the sd1 gene in order to identify useful nonallelic semidwarf genes primarily for upland conditions. Fifty-five thousand seeds were treated with 40 and 45 krad (400 and 450 Gy). Conventional methods of handling and selecting mutant plants were carried out at the Campinas Experimental Center. Sixty-three mutant lines were selected and classified. In 1989 eight and in 1990 ten promising mutant lines were included in preliminary yield trials under upland conditions. In both years IAC 165 yielded more than the selected mutants. Under sprinkler irrigation several mutants yielded as high as IAC 165. Some mutants were later than IAC 165. Preliminary results of crosses involving the eight selected mutants with BR-IRGA 409 indicate that the mutant genes are not allelic to sd1. Crosses of the mutants with IAC 165 indicate that the tall types are dominant. (author). 3 refs, 2 figs, 4 tabs

  18. Induced mutation for tungro resistance in rice

    International Nuclear Information System (INIS)

    Tungro is the most serious virus disease of rice in South and Southeast Asia. It is a composite disease of two kinds of viruses, rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV). Damage to the plant is mostly caused by RTBV, while RTSV acts to facilitate RTBV acquisition and transmission by insect vector. Both viruses are transmitted mainly by green leafhopper (GLH). Resistance to GLH is common in rice germplasm but extremely rare for the two viruses. To induce mutations for tungro resistance, a susceptible variety IR22 was treated with N-methyl-N-nitrosourea (MNH) following the procedure of Satoh and Omura. The panicles of rice variety 'IR22' were soaked in 1 mM MNH solution for 45 minutes at 16 to 18 hours after flowering. Two thousand six hundred and forty fertile M1 plants were produced. From these plants M2 lines with 10 or more seedlings were planted in the field to evaluate their reaction against tungro under natural conditions in the 1990 dry season on the IRRI central research farm, Los Banos, the Philippines. Of these, 124 M2 lines were selected by visual evaluation. Five plants were harvested individually from each selected line. A bulk was also made from all the remaining plants in the line. In the M3 generation, each family consisted of five sister lines and one bulked line. One line (M3-723) showed no tungro symptoms and its related bulk segregated for resistance but all other M3 lines from the same family were susceptible to tungro. The resistant line, M3-723, showed low infection with RTBV and RTSV when leaves were tested by enzyme-linked immunosorbent assay (ELISA) to diagnose tungro infection. All M4 lines from M3-723 showed uniform resistance in the field. They were not infected with RTBV and were resistant to RTSV infection

  19. Studies on induced mutations in garlic

    International Nuclear Information System (INIS)

    Garlic (Allium sativum L.) is the second most widely cultivated Allium - after onion. It has been recognised world-wide as a valuable spice for foods and a popular remedy for various ailments and physiological disorders. The available types of garlic exhibit low variability due to repeated vegetative propagation. As garlic flowers are mostly sterile, restoration of fertility is a difficult process and hence there exists little scope for genetic improvement through hybridization. Induced mutagenesis with gamma rays has helped to overcome these genetic barriers. Ethyl methanesulphonate (EMS) and their combination treatments attempted to improve bulb yield in garlic varieties 'Mettupalayam' and 'Ooty-1' at the Horticultural Research Station, Ooty in Nilgiris. Based on radiosensitivity studies, two doses of gamma rays (2.5 and 5.0 Gy), four concentrations of EMS (15, 20, 25 and 30 mM for 8 h at temperature 25±2 deg. C) and four combined treatments (2.5 Gy + 20 mM, 2.5 Gy + 25 mM, 5.0 Gy + 20 mM and 5.0 Gy + 25 mM) were employed. Garlic bulb and clove characteristics and the varietal response were significantly influenced by the physical, chemical mutagens and their combination treatments. The spectrum of chlorophyll mutants identified in the present study are comprised of, albina, chlorina, straita, viridis and xantha. The proportion of the various mutants varied with the varieties and mutagen treatments. Increasing doses of gamma rays, EMS or combination treatments increased the rate of lethality, injury and clove sterility of treated populations. Mutations for plant, leaf and shoot morphology were more frequent than bulb characters in both varieties. Non-viable mutants were dose dependant and this increased with higher doses. Gamma treatments caused more non-viable mutants (mottled and crinkled leaves) followed by combined and EMS treatments

  20. Induced mutations for improvement of grain legume production II

    International Nuclear Information System (INIS)

    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

  1. Use of induced mutations in soybean breeding

    International Nuclear Information System (INIS)

    Artificial induction of mutation in plants is carried out using #betta#-irradiation and ethyl metanesulphonate (EMS) to expand the genetic variability of locally-grown soybean. This aspect of mutation breeding complements of conventional breeding approach undertaken by the Joint Malaysia Soybean Breeding Project group. Recovery of agronomically-important mutants such as earliness, lateness, bigger seed size and improved plant architecture were recorded. The significance of these findings is discussed. (author)

  2. Radiation-induced mutation breeding of papaya

    International Nuclear Information System (INIS)

    Irradiation-induced mutation breeding of papaya commenced at the Malaysian Agricultural Research and Development Institute (MARDI) in August, 2000. This research was initiated under a Coordinated Research Project (CRP - D23023) with assistance from the International Atomic Energy Agency (IAEA). In the preliminary dosimetry study, seeds from two local papaya varieties, Sekaki and Eksotika were irradiated, either as dry seeds or as pre-soaked seeds (soaked overnight in water and surface-dried) with radiation doses ranging from 0 to 300 Gy. 100 Gy dose was lethal for all wet presoaked seeds while dry seed did not show loss of viability, even at 300 Gy. From the growth data it was estimated that dose of 525 Gy reduced shoot elongation by 50%, and this dose was recommended for mass irradiation of dry seeds. For wet, pre-soaked seeds results indicated that 42.5 Gy was the optimal dose for mass irradiation. At this dose, both seeds germination and seedlings growth were reduced by 50%. In a massive irradiation experiment 2,000 Eksotika seeds were irradiated at 42.5 Gy (pre-soaked) and another 2,000 at 525 Gy (dry). In the M2 population, numerous physiological defects were observed, including stem splitting, leaf variegation and puckering, and crinkled dwarfs. In the M3 population, a wide variability was recorded for a number of traits. M3 seedlings derived from presoaked seeds irradiated a low 42.5 Gy dose presented a high number of plants that were shorter and more vigorous in leaf development compared to those irradiated at 525 Gy and to non-irradiated control seedlings. The distribution patterns of M3 progenies for nine quantitative field characters showed great variation, often exceeding the limits of the control population. There appears to be good prospects in improving Eksotika papaya especially in the development of dwarf trees with lower fruit bearing stature, higher total soluble solids in fruits and larger fruit size. Several M2 and M3 putative mutants also

  3. SIMILARITY ANALYSIS OF DNA SEQUENCES BASED ON THE CHEMICAL PROPERTIES OF NUCLEOTIDE BASES, FREQUENCY AND POSITION OF GROUP MUTATIONS

    Directory of Open Access Journals (Sweden)

    Fatima KABLI

    2016-01-01

    Full Text Available The DNA sequences similarity analysis approaches have been based on the representation and the frequency of sequences components; however, the position inside sequence is important information for the sequence data. Whereas, insufficient information in sequences representations is important reason that causes poor similarity results. Based on three classifications of the DNA bases according to their chemical properties, the frequencies and average positions of group mutations have been grouped into two twelve-components vectors, the Euclidean distances among introduced vectors applied to compare the coding sequences of the first exon of beta globin gene of 11 species.

  4. Rice breeding with induced mutations in France

    International Nuclear Information System (INIS)

    Mutation experiments with rice at Montpellier yielded strains with improved lodging resistance, grain size, maturing time, milling quality and other characters. The general performance of these mutant strains was tested in field trials. Further mutagenic treatments were made to improve the high-yielding short grain varieties with regard to grain quality and seed dormancy. (author)

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

    International Nuclear Information System (INIS)

    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

  6. Induced mutation research in plant breeding

    International Nuclear Information System (INIS)

    The improvement of plants is of great importance to the developing countries. The author briefly describes, with references, recent work on mutation breeding by means of ionizing radiations. The aim of this work is to increase the quantity and quality of plants, e.g. by increasing yield, by developing disease- or insect-resistant varieties, by increasing nutritive value, by improving taste, storage life and appearance. (author)

  7. Improvement of grain legume production using induced mutations

    International Nuclear Information System (INIS)

    This FAO/IAEA Workshop was the final Research Co-ordination Meeting for four FAO/IAEA Co-ordinated Research Programmes, namely: The FAO/IAEA Co-ordinated Research Programme on the Use of Induced Mutations for Improvement of Grain Legume Production in South East Asia, supported since 1976; The FAO/IAEA/Swedish International Development Authority (SIDA) Co-ordinated Research Programme on Induced Mutations for Disease Resistance in Grain Legumes, supported since 1977; The FAO/IAEA Co-ordinated Research Programme on Improvement of Leguminous Food Crops in Africa and the Near East Through Induced Mutations, supported since 1981; The FAO/IAEA Co-ordinated Research Programme on Improvement of Leguminous and Oil Seed Crops in Latin America Through Induced Mutations, supported since 1981. Of the 40 current and former holders of research contracts or research agreements under the above mentioned programmes, 29 were able to attend the Workshop and present their final reports. Participants have attempted to draw general conclusions from their work for a number of topics that may be relevant for other investigators who are considering using induced mutations in legume breeding programmes. The conclusions and recommendations are presented. Refs, figs and tabs

  8. A Fast Determination of DNA Mutation Induced by Ultraviolet Radiation

    Institute of Scientific and Technical Information of China (English)

    LuFeng; LiuLili; ZhangXiaofang; WuYutian

    2001-01-01

    Electrophoresis, chromatography, immunoassay, sequencing and other time consuming ap-proaches have been developed to determine DNA base mismatching, oxidative lesion or strand breaks. Sometimes,however, only qualitative information is enough to decide whether mutation has happened to DNA and its extent.Convolution spectrometry (CS), a new technique to discover ultrafme difference on ultraviolet (UV) absorption ofdifferent substances, is originally employed to find out any subtle mutation of DNA induced by UV radiation. Muta-tive DNA is compared with ego criteria based on the spectra of the former DNA, any difference is quantitatively ex-pressed by dispersion (5). Visible changes cannot be observed on second -derivative spectra until the mutation gets 5up to 11.48%. Dimethyl sulfoxide is an intensifier of UV 254 nm induced DNA mutation and protector at 365 nm,which is simply confirmed by increasing and decreasing 5. Every convolution procedure takes less than 1 min. Convolution spectrometry provides a fast, simple, sensitive and inexpensive alternative to determine DNA mutation, andto screen anti-mutational medicines.

  9. Chlorambucil effectively induces deletion mutations in mouse germ cells.

    OpenAIRE

    Russell, L B; Hunsicker, P R; Cacheiro, N L; Bangham, J W; Russell, W. L.; Shelby, M D

    1989-01-01

    The chemotherapeutic agent chlorambucil was found to be more effective than x-rays or any chemical investigated to date in inducing high yields of mouse germ-line mutations that appear to be deletions or other structural changes. Induction of mutations involving seven specific loci was studied after exposures of various male germ-cell stages to chlorambucil at 10-25 mg/kg. A total of 60,750 offspring was scored. Mutation rates in spermatogonial stem cells were not significantly increased over...

  10. New cultivars of jujube induced by mutation

    International Nuclear Information System (INIS)

    Full text: Mutation breeding of jujube (Ziziphus mauritiana Lin.) received attention by the Food Crops Research Institute since 1978. Mutations can be directly released as new cultivars or indirectly as bud grafting source. N-methyl-N-nitroso urea (MNH) was used at a concentration of 0.02-0.04% for 12 h treatment of pre-germinated seeds of different jujube cultivars. Some useful mutants were selected and directly released as new cultivars to farmers. Of the selected mutants two cultivars, ''Ma hong'' and ''Dao tien'', are the most preferable and popularly grown in the country. ''Ma hong'' is a mutant of ''Gia Loc'', a very popular cultivar. Main useful traits of ''Gia Loc'' such as early maturing, two crops of fruits per year are maintained (harvest in December and August). ''Ma hong'' has round-formed, pink rose coloured, sweeter fruits and stable fruit yield in off-season (Aug.) as compared with oval-formed, yellow-coloured and sour fruit of ''Gia Loc''. ''Dao tien'' is a mutant of the local variety ''Thien Phien'' with quite different traits. The original cultivar is late maturing (harvested in Feb.) with one crop of fruit per year and has small fruits (mean wt. of fruit at harvest 20 g). ''Dao tien'' is one month earlier in maturing allowing two crops of fruit per year (harvested in Jan. and Nov.). Fruits are round-formed, bigger (mean wt. of fruit: 25 g) and more tasteful (peach-flavored and brittle). (author)

  11. Induced mutation in the improvement of beans

    International Nuclear Information System (INIS)

    A program on mutational rectification was undertaken in 1978 utilizing gamma radiation, as seed treatment for three local cultivars of compea, Vigna unguiculata plus one cultivar of mungbean, Vigna radiata. The selection criteria were compact plant type with determinate habit, early maturity, resistance to Macrophomina and high yield. The selected material now in M7 generation, selection being made in M2 for plant type. In subsequent generations selections were made for resistance to Macrophomina, stability of plant type, uniform pod filling, seed size, good nodulation, synchronous flowering and productivity under close spacing conditions. Simultaneous studies on root development were made at seedling stage. In mungbean, emphasis on non-shattering was made. Finally 12 mutants were selected in M5, with uniformity for the cited characters and higher yields than the parental material, ranging from 20 to 110% superior yield in some mutants and sowing dates. Multilocation trials are being conducted to test the wide adaptability of these mutants. Chemical mutagenesis using sodium azide with and without gamma radiation was also used. From these trials nonnodulating mutants were recovered. These materials are being multiplied to be used in basic studies of the Rhizobium - legume symbiosis. Ecophysiological studies of the promising mutants have been carried out under different sowing dates at 45 day intervals. These results are of wide interest in studies of tropical adaptation of grain legumes, on which very few reports are available so far. These results are discussed with particular reference to yield and its stability for the cropping system in Venezuela. (author)

  12. 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...

  13. Specific gene mutations induced by heavy ions

    International Nuclear Information System (INIS)

    This report summarizes our heavy-ion research rationale, progress, and plans for the near future. The major project involves selecting a group of maize Adh1 mutants induced by heavy ions and correlating their altered behavior with altered DNA nucleotide sequences and sequence arrangements. This research requires merging the techniques of classical genetics and recombinant DNA technology. Our secondary projects involve (1) the use of the Adh gene in the fruit fly, Drosophila melanogaster, as a second system with which to quantify the sort of specific gene mutants induced by heavy ions as compared to x rays, and (2) the development of a maize Adh1 pollen in situ monitor for environmental mutagens

  14. X-ray induced mutations, DNA and target theory

    International Nuclear Information System (INIS)

    It is stated that X-ray induced, specific locus, germ-line mutation rates vary significantly in eukaryotes. A consideration of the radiobiology of the individual gene by the author leads to three major conclusions. (1) Mutation rates tend to be much lower than radiation theory predicts. (2) Selection and/or repair are major factors that determine the rates. (3) The mouse 7-locus test, which provides a principal data base for the standards of human radiation hygiene, may not provide adequate overall representation of the mutability of the mammalian genome, so more research is needed. (U.K.)

  15. The Role of Induced Mutations in World Food Security

    International Nuclear Information System (INIS)

    Physical availability and economic accessibility of food are the most important criteria of food security. Induced mutations have played a great role in increasing world food security, since new food crop varieties embedded with various induced mutations have contributed to the significant increase of crop production at locations people could directly access. In this paper, the worldwide use of new varieties, derived directly or indirectly from induced mutants, was reviewed. Some highlights are: rice in China, Thailand, Vietnam, and the USA; barley in European countries and Peru, durum wheat in Bulgaria and Italy, wheat in China, soybean in China and Vietnam, as well as other food legumes in India and Pakistan. An exact estimate of the area covered by commercially released mutant cultivars in a large number of countries is not readily available, but the limited information gathered clearly indicates that they have played a very significant role in solving food and nutritional security problems in many countries. (author)

  16. Radiation induced mutations for breeding of sorghum

    International Nuclear Information System (INIS)

    Several sorghum cultivars of Mali were irradiated with different doses of gamma rays and compared with the Caudatum types. Radio-sensitivity studies suggested that the local types were less sensitive to radiation than the introduced types. Whereas the local varieties survived dose of 300 Gy, in Caudatum types, seed germination and growth were significantly reduced at 200 Gy. Several agronomically important mutants were obtained among the progeny of the local types. Some of the mutants were shorter and had improved panicle characteristics. Radiation-induced variation was observed in several characters such as plant height, resistance to lodging, plant architecture, drought tolerance, panicle length and compactness, seed size and color, seed quality (viterous or floury) and protein content, glume color and structure, flowering data (early and late maturity), and tillering capacity. One mutant was drought tolerant. Promising mutants were selected and are presently under evaluation in the National List Trials to confirm their potential and future release. Selected variants have been also crossed with local types to obtain promising material. (author). 8 refs, 2 tabs

  17. Genetic architecture of flowering time as identified by induced mutations

    International Nuclear Information System (INIS)

    The different studies made to elucidate the genetic system controlling flowering time by means of induced mutations, mainly in Arabidopsis and barley and partly in other plants, are reviewed. It is intended to throw some light on the organization and relationships of the array of gene loci controlling this economically important character. Two hypotheses are proposed. The first is that single plant selections in M2 and onwards generally lead to single gene mutant lines. Single plant selections carrying two mutant genes affecting the same character are relatively rare. Those carrying polygenic mutations are extremely rare. The second hypothesis is that flowering time mutants of different origin are thought to carry mutations at different loci. Analyses of induced changes in flowering time by means of biometrical as well as classical Mendelian methods are compared with respect to the magnitude and direction of individual gene effect, linkage relationships, gene interactions (allelic and non-allelic) and heterosis phenomena. It is concluded that most studies support the proposed hypotheses. Allelism between mutated genes at different loci seems very rare, and the loci controlling flowering time are not evenly distributed all over the genome, but rather cluster in a few linkage groups. Epistatic interactions between flowering time mutant genes seem relatively rare. The effects of the different loci are mostly additive. Heterosis between single gene mutants generally results from complementation between wild-type dominant alleles of the mutated loci. This directly supports the dominance theory of heterosis. Biometrical analysis of induced changes in flowering time generally leads to rough conclusions, mostly similar to those predicted from natural variation. (author)

  18. Genetic Improvement of Chickpea (Cicer arietinum L.) Using Induced Mutations

    International Nuclear Information System (INIS)

    The main target of chickpea breeding programmes has been to develop high yielding cultivars. In an attempt to induce genetic variability for improvement of locally popular chickpea cultivar Vijay (Phule G-81-1-1), we employed three well known mutagens, sodium azide (SA), ethyl methane sulphonate (EMS) and gamma radiation (GR). The objective was to provide genetic variability in the yield contributing traits that can be exploited for a genetic improvement of chickpea. Seeds of Chickpea cultivar Vijay were treated with three different concentrations / doses of SA (2, 3 and 4 mM), EMS (8, 12 and 16 mM) and gamma radiations (400, 500 and 600 Gy). In M1 generation no dominant mutations were observed, many different mutants were screened and isolated in M2 generation such as chlorophyll mutations (alnina, chlorina and xantha); leaf mutations (gigas, compact and curly); pod mutations (small, roundish, gigas and narrow elongated); seed mutations (green, dark brown, rough seed coat); flower mutations (white flower and open); morphological mutations (early, sterile, tall and gigas). True breeding mutant lines in M3 generation differed considerably in their quantitative traits from the parent cultivar. The early mutant lines matured 10 days earlier than the parent variety. The range in plant height was expanded from 0.02 to 14.91cm. Gigas mutant lines obtained after 400 Gy gamma irradiation were the tallest (44.44cm), with a 2-3 fold increase in pod and seed size over the control. Mutagenic treatments also caused changes in seed size and seed coat. Considerable genotypic variation was observed with regards to the number of seeds and pods per plant. Small leaf mutants showed double the number of seeds and pods per plant. As a result of mutagenic treatments, genetic variation was induced in mutants with respect to different quantitative characters. Induced mutant lines showed both positive and negative increase in the quantitative traits. Variation was also observed for crude

  19. Induced Mutations for Improving Production on Bread and Durum Wheat

    Science.gov (United States)

    Stamo, Ilirjana; Ylli, Ariana; Dodbiba, Andon

    2007-04-01

    Wheat is a very important crop and has been bred for food and its improvement is continuous from cross-breeding. Radiation and chemically induced mutations have provided variability in selection for novel varieties. Four bread and one durum wheat cultivars were exposed to gamma rays, Cs 137 with doses 10, 15 and 20 krad (2000 seeds of each dose and cultivars). We have isolated mutant plants with height reduced and on cv Progress spike without chaff.

  20. Induced Mutations for Improving Production on Bread and Durum Wheat

    International Nuclear Information System (INIS)

    Wheat is a very important crop and has been bred for food and its improvement is continuous from cross-breeding. Radiation and chemically induced mutations have provided variability in selection for novel varieties. Four bread and one durum wheat cultivars were exposed to gamma rays, Cs 137 with doses 10, 15 and 20 krad (2000 seeds of each dose and cultivars). We have isolated mutant plants with height reduced and on cv Progress spike without chaff

  1. Induced mutations in plant breeding and biological researches in Japan

    International Nuclear Information System (INIS)

    More than 200 direct-use mutant varieties generated by using irradiation, chemical mutagenesis and somaclonal variations, have been registered in Japan. About 61% of these were induced by gamma ray irradiation and contribution of Institute of Radiation Breeding with the gamma ray irradiation facilities of Gamma Field, the Gamma Greenhouse and the Gamma Room is great. This high percentage of gamma ray irradiated mutants indicates that mutation breeding via gamma ray irradiation is an effective and highly successful approach for the generation of commercial cultivars. Some mutant cultivars of Japanese pear and apple resistant to diseases induced by gamma ray irradiation and development of a unique bioassay by using toxins of fungi will be discussed. In addition, ca. 200 indirect-use (hybrid) mutant varieties primarily generated in rice and soybean have found values as parental breeding germplasm resources in Japan. The contribution of direct- and indirect-use mutant varieties generated through gamma-ray irradiation is significant. In 2005, two direct-use cultivars and 97 indirect-use cultivars contribute approximately 12.4% of the total area for cultivation in Japan. The semidwarf gene (sd-1) generated in rice is perhaps one of the most significant contribution to this. For soybean, similar gammaray induced mutants (4 direct-use cultivars and 4 indirect-use cultivars) cover nearly 9.4 % out of the total cultivation area (ca. 142,000 ha) of soybean. These results indicate that agronomically useful mutations, induced by irradiation mutagenesis, have contributed directly and significantly to food production in Japan. On the other hand, molecular genetics based on genome sequencing will be presumably be the most powerful tool for identifying the genes, which control phenotypes, and for selecting mutants of certain phenotypes. This could change the mutation breeding dramatically, especially in rice, and expand its use into the other gramineous crops which show genomic

  2. Base substitution mutations induced by metabolically activated aflatoxin B1.

    Science.gov (United States)

    Foster, P L; Eisenstadt, E; Miller, J H

    1983-05-01

    We have determined the base substitutions generated by metabolically activated aflatoxin B1 in the lacI gene of a uvrB- strain of Escherichia coli. By monitoring over 70 different nonsense mutation sites, we show that activated aflatoxin B1 specifically induced GxC leads to TxA transversions. One possible pathway leading to this base change involves depurination at guanine residues. We consider this mechanism of mutagenesis in the light of our other findings that the carcinogens benzo[a]pyrene diol epoxide and N-acetoxyacetylaminofluorene also specifically induce GxC leads to TxA transversions. PMID:6405385

  3. Induced mutations in citrus shoot tip culture in vitro

    International Nuclear Information System (INIS)

    This study was undertaken to determine the efficacy of using induced mutation of the callus of citrus clones as a method in citrus breeding. It was observed that the nuclear clones had a higher ratio of callus cell differentiation than the old clones. The callus cells were exposed to gamma irradiation of 7,000 roentgen at 127 R/min. Callus cells derived from the shoot tip proved to be more appropriate for cytological examination by the smearing technique than the root tip cells. Gamma irradiation of callus cells is quite effective for inducing chromosome aberration and micronucleus inspection

  4. Plant breeding: Induced mutation technology for crop improvement

    International Nuclear Information System (INIS)

    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

  5. Induced mutations for a determinate habit in rice bean

    International Nuclear Information System (INIS)

    Induced mutation techniques were used to create polygenic variability in rice bean (Vigna umbellata). Dry seeds of the genotype (sel. I) were irradiated with 40-80 kR of gamma rays at 10 kR intervals. A wide variation in quantitative characters was induced in both the M2 and M3 generations. Some mutants were isolated that showed a determinate growth habit, earliness, a high yield and photoinsensitivity. These mutants were found to be breeding true. (author). 5 refs, 1 tab

  6. Induced mutations and marker assisted breeding approaches to crop improvement

    International Nuclear Information System (INIS)

    The crop improvement programme at the Nuclear Institute for Agriculture and Biology involves use of mutation breeding techniques, particularly for improving plant architecture, maturity, period and induction/incorporation of genes for biotic and abiotic tolerance in important food and fibre crops. Recent advances in molecular genetics offered us new techniques to elucidate differences at the molecular level in the mutated genes with the help of marker assisted breeding techniques, i.e. restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD). Efforts are therefore being made to incorporate salt tolerance in cultivated wheat and rice from their wild relatives through wide hybridization. Thirteen improved varieties of rice, cotton, mungbeam and chickpea have been developed using the mutation breeding technique and then released for commercial cultivation. These improved varieties have played a significant role in increasing agricultural production in the country. In addition, a wealth of genetic variability has been developed for use in the cross-breeding programmes, and a few varieties of cotton have been developed in Pakistan with an induced mutation as one of their parents. Marker assisted wide hybridization in rice has helped to monitor the flow of genetic material carrying salt tolerance from wild to cultivated species. In wheat, DNA fingerprinting has been attempted to differentiate salt tolerant line (hybrids) from their parents

  7. Vacuum-induced Mutations In Bacillus Subtilis Spores

    Science.gov (United States)

    Munakata, N.; Maeda, M.; Hieda, K.

    During irradiation experiments with vacuum-UV radiation using synchrotron sources, we made unexpected observation that Bacillus subtilis spores of several recombination-deficient strains lost colony-forming ability by the exposure to high vacuum alone. Since this suggested the possible injury in spore DNA, we looked for mutation induction using the spores of strains HA101 (wild-type repair capability) and TKJ6312 (excision and spore repair deficient) that did not lose survivability. It was found that the frequency of nalidixic-acid resistant mutation increased several times in both of these strains by the exposure to high vacuum (10e-4 Pa after 24 hours). The analysis of sequence changes in gyrA gene showed that the majority of mutations carried a unique allele (gyrA12) of tandem double-base substitutions from CA to TT. The observation has been extended to rifampicin resistant mutations, the majority of that carried substitutions from CA to TT or AT in rpoB gene. On the other hand, when the spores of strains PS578 and PS2319 (obtained from P. Setlow) that are defective in a group of small acidic proteins (alpha/beta-type SASP) were similarly treated, none of the mutants analyzed carried such changes. This suggests that the unique mutations might be induced by the interaction of small acidic proteins with spore DNA under forced dehydration. The results indicate that extreme vacuum causes severe damage in spore DNA, and provide additional constraint to the long-term survival of bacterial spores in the space environment.

  8. Use of induced mutations in the breeding of pulse crops

    International Nuclear Information System (INIS)

    Four cultivars, Trombay Vishakha-1 (TT-6) and TAT-10 of pigeonpea (Cajanus cajan (L.) Millsp.), TAP-7 of mungbean (Vigna radiata L.) and TAU-1 of blackgram (Vigna mungo Hepper), developed at the Bhabha Atomic Research Centre using induced mutations, have been released for commercial cultivation. During 1989, they covered an area of about 3.3 million hectares. The objective in the current breeding cycle was to improve these. Induced mutations, as well as selections isolated from the germplasm collected, are being used for this purpose. One of the selections (TPM-1) derived from the cross between cv. PIMS-1 and the profusely branched dwarf mutant M-71 had an 18% higher yield than the control, cv. Pusa-105, in the co-ordinated trials. It is now being tested in large scale trials. Meanwhile, a stock (RUM-5) showing an immune reaction to a local isolate of Erysiphe polygoni causing powdery mildew was identified from the germplasm. One selection (TPRM-2) derived from the cross RUM-5 x TPM-1 was completely free of the disease at two locations in a powdery mildew endemic region and had 130 and 79% higher yields than TAP-7 and a local cultivar, respectively. Pigeonpea (cv. TAT-10) was found to be tolerant to pod borers in the co-ordinated programme of pulses and is being using extensively in the national breeding programme. Induced variation has thus provided useful genetic materials for the improvement of pulse crops. (author). 11 refs, 4 tabs

  9. Induced Mutations in Plant Breeding and Biological Researches in Japan

    International Nuclear Information System (INIS)

    Two hundred and forty two direct-use mutant varieties generated by using irradiation, chemical mutagenesis and somaclonal variations, have been registered in Japan. About 61% of these were induced by Gamma-ray irradiation, largely due to successful collaboration with the Institute of Radiation Breeding. This high percentage of Gamma-ray irradiated mutants indicates that mutation breeding via Gamma-ray irradiation is an effective and highly successful approach for the generation of commercial cultivars. Some mutant cultivars of Japanese pear exhibiting resistance to diseases induced by Gamma-ray irradiation and development of a unique bioassay by using toxins of fungi was discussed. In addition, 228 indirect-use (hybrid) mutant varieties primarily generated in rice and soybean have found value as parental breeding germplasm resources in Japan. In 2005, two direct-use cultivars and 97 indirect-use cultivars of rice contributed approximately 12.4% of the total area of rice cultivation in Japan. The semi-dwarf gene (sd-1) generated in rice is perhaps one of the most significant contributions. For soybean, similar Gamma-ray induced mutants comprised nearly 9.4% of the total cultivation area of soybean in Japan. Molecular genetic studies focused on genome sequencing have become an extremely powerful tool for identifying the genes and for selecting mutants exhibiting specific phenotypes. It is anticipated that molecular genetic interaction will complement gains in mutation breeding on a dramatic scale. Chronic irradiation in the Gamma Field is also considered to be a useful tool for generating mutant resources for future molecular studies especially in rice, and expand its use into the other graminaceous crops which have genomic synteny to rice. There are interesting reports concerning mutations in rice, such as low glutelin content, in which the size and location of deletions and the mechanisms and phenotypes of low glutelin content were elucidated. Chronic irradiation

  10. Seed protein improvement in wheat and pulses through induced mutation

    International Nuclear Information System (INIS)

    Gamma rays and chemical mutagens (sodium azide and ethyl methane sulphonate) were used separately to induce mutations in wheat, triticale and mungbean. An increased variation in yield and protein content, determined by dye-binding capacity and the micro-Kjeldahl method, was observed in the M3 and M4 generations as compared with controls. In fertilizer trials an increase in grain yield and protein percentage was found invariably in all the treatments given at different stages in split applications. The genetic diversity was observed in the collections from northern areas of Pakistan regarding the protein content and morphological and physiological characters. (author)

  11. Base substitution mutations induced by metabolically activated aflatoxin B1.

    OpenAIRE

    Foster, P. L.; Eisenstadt, E; Miller, J H

    1983-01-01

    We have determined the base substitutions generated by metabolically activated aflatoxin B1 in the lacI gene of a uvrB- strain of Escherichia coli. By monitoring over 70 different nonsense mutation sites, we show that activated aflatoxin B1 specifically induced GxC leads to TxA transversions. One possible pathway leading to this base change involves depurination at guanine residues. We consider this mechanism of mutagenesis in the light of our other findings that the carcinogens benzo[a]pyren...

  12. Homozygous beta zero-39 mutation with thalassemia intermedia in northern Sardinia: clinical, hematological and molecular analysis.

    Science.gov (United States)

    Oggiano, L; Dore, F; Pistidda, P; Guiso, L; Manca, L; Masala, B; Pirastu, M; Rosatelli, C; Cao, A; Longinotti, M

    1988-01-01

    In this study, we investigated the clinical and hematological features and carried out alpha- and beta-globin gene analyses in 11 Sardinian adult beta zero-thalassemia homozygotes from Northern Sardinia who were not transfusion-dependent. Oligonucleotide analysis revealed in nine out of 11 patients the nonsense mutation at codon 39, which was associated either with haplotype II or IX (14/16 and 2/16 chromosomes, respectively). Haplotype II was linked to the A gamma T mutation. The G gamma globin level ranged from 50 to 70%. Four out of nine patients (44%) were heterozygous and 3/9 (33%) homozygous for the rightward deletional type of alpha-thalassemia; two (22%) had the normal alpha-gene complement. Patients who were alpha-thalassemia homozygotes (-alpha/-alpha) showed a more balanced globin chain synthesis ratio. This study confirms that alpha-thalassemia may ameliorate the clinical picture of homozygous beta zero-thalassemia. PMID:2905346

  13. Induced mutations for improvement of grain legume production

    International Nuclear Information System (INIS)

    After an introduction on plant science research in Malaysia concerning crop breeding, 22 research reports are presented, 17 of which are analyzed individually and constitute separate INIS references. The remaining 5 were essentially concerned with only future applications of nuclear technology: a paper by V.L. Chopra (India) on mutation breeding for partial disease resistance of wheat; by H.H. Hoppe (Federal Republic of Germany) on mechanisms of resistance against Uromyces in Phaseolus vulgaris; by I.S. Santos (Philippines) on induction evaluation and utilization of beneficial mutations in the winged bean (Psophocarpus tetragonolobus), where gamma rays and fast neutrons will be used as well as other mutagens; by F. Saccardo (Italy) on breeding for disease resistance in peas and other vegetables (short communication only); and by E. Balazs and I. Sziraki (Hungary) on in vitro studies on virus resistance of legumes, including virus-host interaction studies involving gamma irradiation (short communication only). The conclusions and recommendations of the Regional Seminar on Induced Mutations for the Improvement of Grain Legumes in S.E. Asia 1975 (IAEA-203, 1977) were considered and generally endorsed, with some clarification. Conclusions and recommendations are given on p.121-126

  14. Radiation induced mutations in Phaseolus vulgaris L. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rubeai, M.A.F. (Garyounis Univ., Benghazi (Libya). Dept. of Botany)

    1982-09-01

    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.

  15. Gamma-ray induced mutation breeding in tree fruit crops

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Yuji [Lab. of Radiation Breeding II, Institute of Radiation Breeding, National Institute of Agrobiological Resources, Ministry of Agriculture, Forestry and Fisheries, Omiya, Ibaraki (Japan)

    1998-12-31

    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 {sup 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

  16. Gamma-ray induced mutation breeding in tree fruit crops

    International Nuclear Information System (INIS)

    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 60Co 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

  17. Molecular characterization of microbial mutations induced by ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ichida, Hiroyuki [Graduate School of Science and Technology, Chiba University, Matsudo, Chiba 271-8510 (Japan); Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)], E-mail: ichida@riken.jp; Matsuyama, Tomoki [Cellular Biochemistry Laboratory, Discovery Research Institute, RIKEN, Wako, Saitama 351-0198 (Japan); Ryuto, Hiromichi [Accelerator Operation Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Hayashi, Yoriko [Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Fukunishi, Nobuhisa [Accelerator Operation Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Abe, Tomoko [Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Koba, Takato [Graduate School of Science and Technology, Chiba University, Matsudo, Chiba 271-8510 (Japan)

    2008-03-01

    A positive selection system for gene disruption using a sucrose-sensitive transgenic rhizobium was established and used for the molecular characterization of mutations induced by ion beam irradiations. Single nucleotide substitutions, insertions, and deletions were found to occur in the sucrose sensitivity gene, sacB, when the reporter line was irradiated with highly accelerated carbon and iron ion beams. In all of the insertion lines, fragments of essentially the same sequence and of approximately 1188 bp in size were identified in the sacB regions. In the deletion lines, iron ions showed a tendency to induce larger deletions than carbon ions, suggesting that higher LET beams cause larger deletions. We found also that ion beams, particularly 'heavier' ion beams, can produce single gene disruptions and may present an effective alternative to transgenic approaches.

  18. Improvement of sugar-cane through induced mutations

    International Nuclear Information System (INIS)

    Results obtained on the use of induced mutations in sugar-cane breeding are summarized. Six commercial varieties under cultivation in India were subjected to mutagenic treatment for inducing mutations for specific characters. More than 50 mutants for various morphological characters, disease resistance and higher sugar content were obtained in these varieties. They were multiplied and studied for their stability for four to five years. Mutants of economic value include glabrous leaf sheath, non-flowering, vigorous and high-yielding mutants in Co 527, high-sugared and early maturing mutants in Co 419 and mutants for smut and disease resistance in Co 1287 and Co 740. Two mutants, one in Co 527 and the other in Co 419, have entered the All India Co-ordinated trials because of their superiority in yield and quality over the parent variety. Smut-resistant mutants of Co 1287 and Co 740 are being evaluated in large-scale trials. Tissue culture techniques have been used for propagating the mutants. Genetic variability has also been created by obtaining plants from callus culture with different chromosome numbers. (author)

  19. 70 years induced mutations - To be reconsidered? Topic for discussion

    International Nuclear Information System (INIS)

    According to the prevailing concept at that time, ''qualitative traits'' were assumed to be controlled by one or very few genes, ''quantitative traits'' by many genes. One had already learned that genes could freely recombine, unless they were tightly linked in a chromosomal section. Great attention was paid to ''gene/environment interactions'', separating traits with ''high heritability'' from those with ''low heritability''. Mutagenesis, however, was supposed to be capable of altering all genes irrespective of their chromosomal location, linkage group or level of heritability. Those with ''high heritability'' of course were easier to handle and identified as the more promising targets for mutation induction. When plant breeders speak about gene/environment interactions, the environment is usually considered under the aspect of physical and chemical conditions outside the plant (e.g. location, year, stress), supporting or restricting performance. This neglects the fact that interaction among genes creates some kind of ''genetic environment''. Plant breeders tend to focus on particular genes assumed to be responsible for traits relevant for cultivar improvement. The other genes are downgraded by being lumped into the ''genetic background''. This thinking also prevailed so far in application of induced mutations in breeding programmes

  20. Induced mutations in the improvement of mentha species

    International Nuclear Information System (INIS)

    A comprehensive study on the induced mutagenesis of the three commercially important species of Mentha; M. arvensis, var. piperascens; M. citrata and M. piperita, was initiated in 1970. Dormant suckers/stolons were exposed to X- and gamma rays (3 to 10 kR). Treated suckers/stolons were planted singly and surviving seedlings carefully examined for mutations using visual, analytical techniques and olfactory assessment of the oils to detect biochemical and qualitative mutants. The mutants selected were propagated through two vegetative cycles to ascertain their genetic stability and field performance. Eventually, a few economically useful and some novel biochemical mutants were isolated. Desirable mutants were subjected to agronomic and chemical evaluation over a period of three years. Consequently one clone of M. arvensis (RRL-118/3) was released for commercial cultivation early this year. This mutant has a potentiality of giving upto 40% more menthol per unit area over the currently available commercial strain. (author)

  1. Improving protein quality of soybean through induced mutations

    International Nuclear Information System (INIS)

    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 60Co 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)

  2. Induced mutations for disease resistance in Stylosanthes guyanensis (Aubl.) Sw

    International Nuclear Information System (INIS)

    Stylosanthes Sw. is a genus that originated in Central and South America and now can be found virtually throughout the tropics and, to a lesser extent, in the subtropics. Owing to its hardiness, Stylosanthes is very promising for use as a pasture plant for growing in very poor soils characterized by Al3+ saturation of 60%. Several species of this genus, including S. guyanensis, have their potential limited by the incidence of anthracnose, caused by Colletotrichum gloeosporioides. Efforts based on natural resistance were not very promising and so research work was begun using induced mutations to obtain sources of resistance. Radiosensitivity determination was carried out on the basis of lethal dose 50 (38 kR) and growth rate 35 (48.5 kR). Paternal seeds were treated and sown in the field in lines of individual plants. The M1 generation was harvested using the bulk method in August 1984 and was taken to the field in December 1984. Seeds treated at 48.5 kR were sown in January 1984. The M2 generation, treated at 38 kR, was set under conditions of high natural anthracnose incidence. The M1 generation, treated at 48.5 kR, was replanted in January 1986. Irradiation treatments since 1984 indicated the presence of two atypic individuals. It seems that treatment at 48.5 kR affected seed production, reducing the yield. Under natural conditions, anthracnose incidence was very light until now. However, another year will be necessary to completely evaluate the effect of treatments on disease occurrence. Artificial inoculation with a very high concentration of spores will yield evidence of individuals which have acquired resistance to anthracnose through induced mutations. (author). 8 refs, 2 figs, 1 tab

  3. Molecular analysis of heavy ion induced mutations in the budding yeast

    International Nuclear Information System (INIS)

    This study is intended to elucidate the molecular mechanism of the mutagenesis caused by High-linear energy transfer (LET) ion beam. The frequency of DNA double stranded breaks (DSBs) was estimated by agarose gel electrophoresis. Moreover, the mutation sites of ura3 mutants were determined by DNA sequencing. The yeast cells were irradiated with carbon ions (12C5+; 290 MeV) with the dose 50 to 200 Gy. Carbon ion beam was generated from synchrotron in HIMAC. The carbon ion beams at 100 Gy generate mutations 10.3 - fold more than spontaneous mutation. The mutation frequency increased consistently with LET. This result indicates the high LET ion beam is more mutagenic than low LET ion beam. 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. (author)

  4. Biological effects of space-induced mutation on robinia pseudoacacia

    International Nuclear Information System (INIS)

    Dry seeds of Robinia pseudoacacia were carried by Shijian No.8 breeding satellite for mutagenesis and the biological effect of space-induced mutation was studied. The parameters of Robinia pseudoacacia such as plant height, stem base, branch number, knot spacing, length of thorn and chlorophyll content were analyzed, and, at the same time, the genetic diversity was tested by SSR marker. The results showed that the plant height and stem base of 2-year-old seedlings which derived from space mutagenesis were 22.0% and 24.1% lower than those of control, and 3-year-old seedlings were 13.1% and 22.4% lower than those of control, respectively. While the inhibiting effect of plant height became undermined in the following growth years. However, the inhibiting effect in stem base existed all the time,the length of thorn of branch and stem were 15.6% and 28.6% shorter than the control,respectively. Compared with the control,the variation of the length of thorn from stem was extremely significant. The variation of chlorophyll a content from space mutagenesis compared with control was not remarkable, while the total chlorophyll and chlorophyll b contents were 18.7% and 9.7% lower than those of control, respectively, and the difference between space mutagenesis and control was significant. While the chlorophyll a/b was 25.6% higher than that of control, but the difference was not significant. The coefficient of variation of the relative traits was increased by the space mutagenesis. The extensively population genome mutation after space-induction were not detected by SSR (Simple Sequence Repeats). (authors)

  5. Role of induced mutations in world food security

    International Nuclear Information System (INIS)

    Ever since the epoch making discoveries made by Muller and Stadler eighty years ago, induced mutations have made significant contributions in development and release of >3000 mutant cultivars by a large number of countries in the world in more than 175 crop species. China and India are the top two countries of the world, which have released the largest number of mutant cultivars in several crop species. Gamma rays have been found to be most convenient, useful and successful in release of the largest number of mutant cultivars in the world. The success stories of commercially released mutant cultivars occupying substantial area in several countries of the world started in the fifties and sixties and continued till seventies and eighties. These four decades were ruled by some of the very widely known high yielding mutant cultivars such as Pallas, a two-row barley mutant cultivar in Sweden; Sanilac, a navy pea bean mutant cultivar; Stadler, a wheat mutant cultivar, Calrose, a rice mutant cultivar and Pennrad and Luther, two barley mutant cultivars in USA; Castelporziano, Castelfusano and Creso, the three durum wheat mutants in released in Italy; Balder, a barley mutant and stiff straw oat mutants Rythi and Puhti in Finland; Diamant, a barley mutant in Czechoslovakia; Trumpf, the best known barley mutant cultivar in Germany; Jagannath, a rice mutant cultivar, Aruna, an early maturing castor mutant, a number of Trombay Groundnut (TG) mutant cultivars and TAU-1, a blackgram mutant released in India. The last two decades have also seen release of several high yielding and biotic stress resistant mutant cultivars of rice in China and Vietnam; cotton, wheat, chickpea and mungbean mutants being cultivated in millions of hectares in Pakistan. India has successfully released the largest number of high yielding and disease resistant mutant cultivars in a number of legume crops being cultivated in large areas in the country. Although an exact estimate of the area covered by

  6. Oilseed cultivars developed from induced mutations and mutations altering fatty acid composition

    International Nuclear Information System (INIS)

    One hundred and sixty-three cultivars of annual oilseed crops, developed using induced mutations, have been officially approved and released for cultivation in 26 countries. The maximum number of cultivars have been released in soybean (58), followed by groundnut (44), sesame (16), linseed (15), rapeseed (14), Indian mustard (8), castorbean (4), white mustard (3) and sunflower (1). The majority (118 of 163) of the cultivars have been developed as direct mutants and 45 of 163 by using the induced mutants in a crossing programme. While in soybean 53 out of 58 cultivars were selected as direct mutants, in groundnut 22 from 44 were developed after hybridization. Eighty-three cultivars were developed directly by exposing seeds to gamma or X-rays. Attempts have been made to infer the successful dose range, defined as the range which led to the development, registration and release of the maximum number of mutant cultivars for gamma and X-rays. The successful dose ranges in Gy for the main oilseed crops are: soybean 100-200, groundnut 150-250, rapeseed 600-800, Indian mustard 700 and sesame 100-200. The main characteristics of the new cultivars, besides higher yield, are altered plant type, early flowering and maturity and oil content. Mutants altering fatty acid composition have been isolated in soybean, rapeseed, sunflower, linseed and minor oil crops. New cultivars having altered fatty acid composition have been released in rapeseed, sunflower and linseed. The latter, previously grown for non-edible oil, has been converted to a new edible oil crop. (author)

  7. Grain legume cultivars derived from induced mutations, and mutations affecting nodulation

    International Nuclear Information System (INIS)

    Two hundred and sixty-five grain legume cultivars developed using induced mutations have been released in 32 countries. A maximum number of cultivars have been released in soybean (58), followed by common bean (50), groundnut (44), pea (32) and mungbean (14). Gamma or x-ray exposures of seeds led to the direct development of 111 cultivars, while neutron and chemical mutagen treatments resulted in 8 and 36 cultivars respectively. One hundred and three cultivars have been developed using mutants in cross breeding. Attempts have been made to estimate the successful dose range for gamma and x-rays, defined as the dose range, which led to the development, registration and release of a maximum number of mutant cultivars. Exposures to seeds ranging between 100-200 Gy in all grain legumes, except faba bean, resulted in 49 out of 111 cultivars being developed as direct mutants. Successful doses reported for faba bean are lower than 100 Gy. Modified crop plant characters are listed. Besides the development of new cultivars, a large number of induced mutants that show altered nodulation pattern have been isolated in grain legumes. Such mutants have made a significant contribution in basic studies on host-symbiont interactions and towards cloning of plant genes related to symbiosis and nitrogen fixation. Their exploitation in breeding programs for enhancing nitrogen fixation is just beginning. Available information on nodulation mutants in grain legume crops is summarised. Mainly, four types of nodulation mutants have been isolated. They show either: no nodulation (nod -), few nodules (nod +/-), ineffective nodulation (Fix-), hypernodulation (nod ++) or hypernodulation even in the presence of otherwise inhibitory nitrate levels (nts). Hypernodulating and nts mutants are of great interest. A soybean cultivar incorporating nts trait has been released in Australia. (author)

  8. 60Co γ-irradiation induced mutation breeding of ginger

    International Nuclear Information System (INIS)

    Sprout rhizome and plumelet rhizome of Laiwu ginger were irradiated by 60Co γ-rays at different doses (20, 25, 30 and 35 Gy), and the variations at the VM1, VM2, and VM3 generations were studied. The results showed that the inhibition effect of irradiation on the VM1 generation was found to be increased as the dose increased, and the sprout rhizome was more sensitive to γ-irradiation than the plumelet rhizome. The LD50 and LD60 dose of plumelet rhizomes were 20 and 25 Gy, respectively, and the optimum irradiation dose was 25Gy. The LD50 and LD60 dose of sprout rhizomes were below 20 Gy. Seven types of mutants were found and selected in VM2 generation. The induced mutation characters were unstable in the VM3 generation. Three mutant lines (GDC2531, PZC3026, ZLX2007) selected from VM3 generation showed high yield, and fresh weight of rhizomes increased 33.5%, 27.5% and 24.9%, respectively compared to control. (authors)

  9. Induced mutations in rice improvement - - a decade of progress

    International Nuclear Information System (INIS)

    The mutation breeding technique has been successfully exploited in bringing about desirable changes in crop plants especially during the last decade. Seven local cultivars and IR-8 were treated with gamma rays, ethylmethane sulphonate, diethyl sulphate, hydrazine, etc. In M2 several plant and grain type mutants were recovered and grown in subsequent generations. About 36 fine grain mutants recovered from IR-8 and 125 grain shape mutants from the local cultivars were screened for their grain quality. Some of the IR-8 fine grain mutants were transluscent with higher protein content and deeper distribution of protein in the endosperm. The mutants from the local cultivars ranged in protein content from 5.5 to 13.7%. Some of the mutants had better cookin.o. quality than their controls. A survey of the World rice germplasm by the International Rice Research Institute, Philippines has shown that except for K8 and Chang-chu-ai-11, all the other dwarfs were allelic to the Dee-Geo-Woo-Gen dwarfing gene. Induced dwarfs may therefore offer alternative sources for dwarfing genes. About 63 short statured mutants were recovered from the local cultivars and genetic studies with five of the morphologically distinct dwarfs from Tellakattera have indicated their non-allelism with Dee-Geo-Woo-Gen and also amongst themselves. These dwarfs may be utilised in breeding programmes aimed at developing new high yielding varieties to avoid the genetic vulnerability. (author)

  10. Induced mutation breeding for the improvement of rice in Malaysia

    International Nuclear Information System (INIS)

    The first application of nuclear technology in mutation breeding for the improvement of rice was undertaken by the Malaysian Institute for Nuclear Technology Research (MINT) in December, 1984 for a Coordinated Research Programme under RCA/IAEA/FAO entitled Semi Dwarf Mutants for Rice Improvement in Asia and Pacific. The main objective was to generate semi dwarf mutants in both native and improved cultivars for possible use as new released cultivars or as parents in cross breeding programmes. Within five years, 101 semi dwarf mutants which have the potential to be used as new cultivars or as parents in cross breeding were identified. Twenty nine of the semi dwarf mutants have grain yield between 6000-7300 kg/ha which were classified as potentially good yielding mutants. The parent, Manik yielded about 5700 kg/ha. Forty seven mutants have grain yield between 5000 6000 kg/ha and 25 mutants yielded in the range of 4300-5000 kg/ha. Twelve mutants are resistant to BPH (brown planthopper) but only one, mutant ML15 has grain yield (6300 kg / ha) better than the parent. One of the most striking effects of radiation (gamma ray) was the formation of glutinous rice (Manik 817) with both good yield and head recovery. It is also interesting to note that one of the mutants (MA 03) shows a drastic change in its characteristics and performs better than the parent and other mutant lines. This mutant was late popularly known as mutant Tongkat Ali because of its: outstanding agronomic features such as very erect panicle even after grain filling, very strong culm and resistance to lodging. Even though this mutant was not officially released, due to its unique characteristics and high yield, it has been planted commercially by several farmers especially in the northern parts of Malaysia. More collaborative research programmes using induced mutation breeding have been carried out between MINT, MADA and also MARDI with the aim of producing new potential varieties with high yield, disease

  11. Exercise-induced mitochondrial p53 repairs mtDNA mutations in mutator mice

    OpenAIRE

    Safdar, Adeel; Khrapko, Konstantin; Flynn, James M.; Saleem, Ayesha; De Lisio, Michael; Johnston, Adam P. W.; Kratysberg, Yevgenya; Samjoo, Imtiaz A.; Kitaoka, Yu; Ogborn, Daniel I.; Little, Jonathan P.; Raha, Sandeep; Parise, Gianni; Akhtar, Mahmood; Bart P Hettinga

    2016-01-01

    Background Human genetic disorders and transgenic mouse models have shown that mitochondrial DNA (mtDNA) mutations and telomere dysfunction instigate the aging process. Epidemiologically, exercise is associated with greater life expectancy and reduced risk of chronic diseases. While the beneficial effects of exercise are well established, the molecular mechanisms instigating these observations remain unclear. Results Endurance exercise reduces mtDNA mutation burden, alleviates multisystem pat...

  12. An RNA Aptamer Inhibits a Mutation-Induced Inactivating Misfolding of a Serpin

    DEFF Research Database (Denmark)

    Madsen, Jeppe B; Andersen, Lisbeth M; Dupont, Daniel M;

    2016-01-01

    ) or extracellularly (type-II serpinopathies). We have isolated a 2'-fluoropyrimidine-modified RNA aptamer, which inhibits a mutation-induced inactivating misfolding of the serpin α1-antichymotrypsin. It is the first agent able to stabilize a type-II mutation of a serpin without interfering with the...

  13. Use of induced mutations for crop improvement programmes in Sri Lanka

    International Nuclear Information System (INIS)

    The use of radiation induced mutations is an effective additional tool for plant breeding work in Sri Lanka. Mutation Breeding could be effectively utilized to create favourable specific changes such as short culms, 90o resistance to pests and diseases, improvement in grain quality etc

  14. Genetic Improvement of Soybean Variety VLS-2 through Induced Mutations

    International Nuclear Information System (INIS)

    The narrow genetic base of cultivated varieties in soybean is of global concern. Mutations, spontaneous or induced, are an important source of genetic variability. Seeds of soybean cultivar VLS -2 were irradiated with 250Gy Gamma-rays. A large number of mutants with altered morphological characters like plant height, flower color, sterility, leaf shape, number of pods per plant, seed color, early or late maturity were identified and characterized. Significantly higher oil content was observed in the mutant M-387 (22.7%) and dwarf mutant M-126 (20.7%) as compared to the parent VLS-2 (19.7%). A modified rapid and reliable micro titration plate technique was developed and used for screening trypsin inhibitor (TI) content in the seeds of 7480 M2 plants. The TI content in the M5 generation ranged from 13.5 TIU/mg seed meal to 22.9 TIU/mg seed meal. Significantly lower level of TI was observed in the mutants M-104 (13.5 TIU/mg seed meal), M-213 (14.0 TIU/mg seed meal) and M-291 (15.7 TIU/mg seed meal) as compared to the parent VLS-2 (22.4 TIU/mg seed meal). In the M5 generation, 24 mutant lines were evaluated for various quantitative characters. Analysis of variance showed highly significant variations among mutant lines for yield per plant. Mutant M-17 had the yield per plant of 13.1gm, significantly higher than the parent VLS-2 (8.3 gm). This mutant also exhibited more branches, more pods and higher harvest index. Genetic diversity study indicated that mutant M-17 had maximum dissimilarity value of 24% from the parent. These identified mutants can be utilised in the breeding programme for developing elite varieties of soybean. (author)

  15. Mutations induced by ultraviolet radiation affecting virulence in Puccinia striiformis

    International Nuclear Information System (INIS)

    Uredospores of parent culture, cy 29-1, were treated by ultraviolet radiation and mutations to virulent were tested on resistant wheat cultivars inoculated with treated spores. 7 mutant cultures virulent to the test cultivars were developed with estimated mutation rate 10~6~10~4. The virulence of mutant cultures was different from the all known races of stripe rust. Resistance segregation to mutant cultures was detected in two test cultivars. The results suggested that mutation was important mechanism of virulence variation operative in asexual population of rust fungi

  16. Breeding high yielding varieties of pigeon pea, mungbean and black gram using induced mutations

    International Nuclear Information System (INIS)

    The present communication emphasis the developing of high yielding varieties of pigeon pea, mungbean and black gram using induced mutation with disease resistance in these crops. This would help in stabilisation of the higher yield potential

  17. Particle-induced chromosome aberrations and mutations: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, S. [Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)

    1997-09-01

    This overview will focus on progress in chromosome and mutation studies achieved by the application of new techniques. Furthermore, recent relevant data on longterm genetic effects of densely ionizing radiation will be summarized. (orig./MG)

  18. Sample preparation method for induced mutation on orchid

    International Nuclear Information System (INIS)

    Studies on the induction of mutation in Dendrobium orchid at MINT has produced a number of new orchid mutant cultivars. Tissue culture techniques on orchid seeds and meristem cloning are employed in preparing the samples for the mutation induction. Solid medium based on the Murashige and Skoog (1962) and liquid medium based on Vacin and Went (1949) were found to be suitable in producing protocorm like bodies (PLBs) that are required for the irradiation treatment. (Author)

  19. Global impact of induced mutation in plant breeding

    International Nuclear Information System (INIS)

    Sudden, heritable changes in the genetic material, DNA, are known as mutations. Selection of naturally occurring mutations in wild, ancestral species helped humans in the domestication and further improvement of today's crop plants. Although Charles Darwin was unaware in 1859 of variation and mutations in living organisms, his theory of evolution by natural selection assumed variability. Much later, it was established that mutations are the source of biodiversity, and the driving force for evolution. Gregor Mendel in 1865 also used several mutants in his experiments with garden pea to formulate the laws of inheritance. The term mutation itself was used for the first time by Hugo de Vries in 1901 in his mutation theory. Plant breeding based on the science of genetics, as practiced over the past 100 years, exploited the available genetic variability in the primary gene pool of crop plants, and sometimes in related species. This approach enlarged the yield potential of crops several fold. It also a) improved the stability of yield by incorporating resistance to various biotic and abiotic stresses; b) improved quality of the produce; and c) altered the adaptability of crop species, providing opportunities to grow new crops for food security outside their traditional range. Genetically improved seed (or other planting material) is the most significant input for developing sustainable cropping systems for food security and economic growth. Half of the increased productivity of today's crop plants comes from genetic improvements. The other half is contributed by inputs and management practices

  20. Performance of computational tools in evaluating the functional impact of laboratory-induced amino acid mutations.

    Science.gov (United States)

    Gray, Vanessa E; Kukurba, Kimberly R; Kumar, Sudhir

    2012-08-15

    Site-directed mutagenesis is frequently used by scientists to investigate the functional impact of amino acid mutations in the laboratory. Over 10,000 such laboratory-induced mutations have been reported in the UniProt database along with the outcomes of functional assays. Here, we explore the performance of state-of-the-art computational tools (Condel, PolyPhen-2 and SIFT) in correctly annotating the function-altering potential of 10,913 laboratory-induced mutations from 2372 proteins. We find that computational tools are very successful in diagnosing laboratory-induced mutations that elicit significant functional change in the laboratory (up to 92% accuracy). But, these tools consistently fail in correctly annotating laboratory-induced mutations that show no functional impact in the laboratory assays. Therefore, the overall accuracy of computational tools for laboratory-induced mutations is much lower than that observed for the naturally occurring human variants. We tested and rejected the possibilities that the preponderance of changes to alanine and the presence of multiple base-pair mutations in the laboratory were the reasons for the observed discordance between the performance of computational tools for natural and laboratory mutations. Instead, we discover that the laboratory-induced mutations occur predominately at the highly conserved positions in proteins, where the computational tools have the lowest accuracy of correct prediction for variants that do not impact function (neutral). Therefore, the comparisons of experimental-profiling results with those from computational predictions need to be sensitive to the evolutionary conservation of the positions harboring the amino acid change. PMID:22685075

  1. Helicobacter pylori induces mitochondrial DNA mutation and reactive oxygen species level in AGS cells

    Directory of Open Access Journals (Sweden)

    Xue-Wen Huang, Rui-Hua Luo, Qi Zhao, Zhong-Ze Shen, Li-Li Huang, Xian-Yuan An, Lan-Jing Zhao, Jie Wang, Yu-Zheng Huang

    2011-01-01

    Full Text Available To investigate the role of ROS in the helicobacter pylori (Hp induced mtDNA mutations, AGS cells were treated by extracts of Hp11638 or Hp11638M. The ROS levels, cytochrome C reductions, and intracellular ATP levels were measured. The coding region and the D-Loop region were amplified and sequenced. Results showed the ROS levels, cytochrome C reduction and mtDNA mutations were markedly increased and cell viability decreased after treatment with both Hp extracts, and 616 mutations were detected in D-Loop region and 3 heteroplasmic point mutations in the Cytb gene. No mutations were found in the coding region. The mutation rates of mtDNA D-Loop region were positively correlated with the ROS levels and negatively to the ATP levels.

  2. Molecular analysis of heavy ion induced mutations in the budding yeast

    International Nuclear Information System (INIS)

    The aim of this study is to elucidate the relation between linear energy transfer (LET) and mutagenesis. Carbon ion beams with varied LET generated by Heavy Ion Medical Accelerator in Chiba (HIMAC) synchrotron were irradiated to several types of yeast cells, and we examined the survival rate and mutation frequencies. The results showed that the survival rates were reduced along with the LET, while the mutation frequencies were enhanced along with the LET, and the mutation frequencies increased consistently with LET. The sequencing analysis of mutations showed that the low LET carbon ion beams induced more deletion and insertion mutations than high LET carbon ion beams did. Furthermore, we also examined the gene expression analysis of RAD50, RAD52 and OGG1 after ion beam radiation to cells. The result indicated that the high-LET carbon-ion beams induced the expression of RAD50 gene. (author)

  3. Performance of computational tools in evaluating the functional impact of laboratory-induced amino acid mutations

    OpenAIRE

    Gray, Vanessa E.; Kimberly R Kukurba; Kumar, Sudhir

    2012-01-01

    Summary: Site-directed mutagenesis is frequently used by scientists to investigate the functional impact of amino acid mutations in the laboratory. Over 10 000 such laboratory-induced mutations have been reported in the UniProt database along with the outcomes of functional assays. Here, we explore the performance of state-of-the-art computational tools (Condel, PolyPhen-2 and SIFT) in correctly annotating the function-altering potential of 10 913 laboratory-induced mutations from 2372 protei...

  4. Plant cultivars derived from mutation induction or the use of induced mutants in cross breeding

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

  6. Cellular and deafness mechanisms underlying connexin mutation induced hearing loss – A common hereditary deafness

    Directory of Open Access Journals (Sweden)

    Hong-Bo Zhao

    2015-05-01

    Full Text Available Hearing loss due to mutations in the connexin gene family which encodes gap junctional proteins is a common form of hereditary deafness. In particular, connexin 26 (Cx26, GJB2 mutations are responsible for ~50% of nonsyndromic hearing loss, which is the highest incidence of genetic disease. In the clinic, Cx26 mutations cause various auditory phenotypes ranging from profound congenital deafness at birth to mild, progressive hearing loss in late childhood. Recent experiments demonstrate that congenital deafness mainly results from cochlear developmental disorders rather than hair cell degeneration and endocochlear potential (EP reduction, while late-onset hearing loss results from reduction of active cochlear amplification, even though cochlear hair cells have no connexin expression. Moreover, new experiments further demonstrate that the hypothesized K+-recycling disruption is not a principal deafness mechanism for connexin deficiency induced hearing loss. Additionally, there is no clear relationship between specific changes in connexin (channel functions and the phenotypes of mutation-induced hearing loss. Cx30, Cx29, Cx31, and Cx43 mutations can also cause hearing loss with distinct pathological changes in the cochlea. These new studies provide invaluable information about deafness mechanisms underlying connexin mutation induced hearing loss and also provide important information for developing new protective and therapeutic strategies for this common deafness. However, the detailed cellular mechanisms underlying these pathological changes and pathogeneses of specific-mutation induced hearing loss remain unclear. Finally, little information is available for humans. Further studies to address these deficiencies are urgently required.

  7. Heavy ion induced mutations in mammalian cells: Cross sections and molecular analysis

    Science.gov (United States)

    Stoll, U.; Schmidt, P.; Schneider, E.; Kiefer, J.

    1994-01-01

    Our investigations of heavy ion-induced mutations in mammalian cells, which had been begun a few years ago, were systematically continued. For the first time, it was possible to cover a large LET range with a few kinds of ions. To do this, both UNILAC and SIS were used to yield comparable data for a large energy range. This is a necessary condition for a comprehensive description of the influence of such ion parameters as energy and LET. In these experiments, the induced resistance against the poison 6-thioguanin (6-TG), which is linked to the HPRT locus on the genome, is being used as mutation system. In addition to the mutation-induction cross-section measurements, the molecular changes of the DNA are being investigated by means of Multiplex PCR ('Polymerase Chain Reaction') gene amplification. From these experiments we expect further elucidation of the mutation-inducing mechanisms composing the biological action of heavy-ion radiation.

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

    International Nuclear Information System (INIS)

    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

  9. Molecular analysis of 60Co gamma-ray-induced mutation at HPRT locus in human promyelocyte leukemia cells

    International Nuclear Information System (INIS)

    Objective: To explore the spectra and mechanism of human HPRT gene mutation induced by 60Co γ-rays and its relation with anti-tumor effect of radiation. Methods: Single cell clone culturing, two-way screening count, multiplex PCR amplification and electrophoresis technique were used. Results: (1) When doses were increasing, cell plating efficiency reduced and mutation frequency increased. (2) The most frequent spontaneous mutations were point mutation (92.3%) and gamma-ray-induced mutation, including mainly partial deletion and point mutation (61.7% and 38.3%, respectively). (3) There were deletion mutations in all 9 exons of HPRT gene and the most of gamma-ray-induced mutations were chain deletion with multiplex exons (97.9%). Conclusion: The spectra of spontaneous and gamma-ray-induced mutants were different. The bigger changes in genetic structure are related to the antitumor mechanism of radiation

  10. Analysis of libraries of 'Micro-Tom' tomato mutations induced by heavy-ion bombardment

    International Nuclear Information System (INIS)

    Fruit setting, development, and ripening are complex, genetically programmed processes. Identifying the factors that control these processes is important for understanding the mechanisms of reproductive development. We induced mutations in the tomato cultivar 'Micro-Tom' by irradiation with accelerated heavy ions (HII), recently established as an effective method for inducing mutations in plants, and constructed mutation libraries. 'Micro-Tom' showed lower sensitivities to higher HII doses. The survival rate of 'Micro-Tom' was about 50% with both ions. Screening 6,814 M1 plants, we found various mutations, including those affecting the sizes of plants, leaves, or fruit, and one conferring a broccoli-like inflorescence. This M1 mutant resembles tomato anantha mutant,in which the development of floral primordia is blocked before organogenesis. Because we could not obtain seeds from this mutant, inheritance and segregation of the trait are unknown, but anantha was reported, caused by a recessive mutation. The isolation of monogenic homozygous recessive mutants in the M1 generation has not commonly been described in other mutational studies using many plant species, although our group isolated such mutants in sweet pepper by M1 plant selection in HII mutational studies. To date, we have visually phenotyped 1,175 M2 families (five sibs per line) in the field, and found 262 plants differing from the wild type in one or more characteristics. These results suggest that such mutation libraries could be powerful tools to explain the reproductive development of plants. (author)

  11. Development of improved rice varieties through the use of induced mutations in Malaysia

    International Nuclear Information System (INIS)

    Beginning in 1972, the use of induced mutations for rice improvement was initiated in Malaysia. The initiative became more significant when, in 1979, UKM and MARDI undertook a major and concerted effort to screen for blast resistance in Mahsuri, a popular variety at the time, which had succumbed to the disease. Mutation breeding has used both EMS and gamma irradiation, which comes from a 60Co source at UKM and MINT facilities, and this approach, has now become part and parcel of the overall national rice breeding and selection programmes. Mutation breeding was aimed at developing inter alia disease resistance, insect resistance, photoperiod insensitivity, short stature, reduced maturity, improved plant type and good grain and eating qualities, and involved many rice genetic resources, ranging from traditional varieties to advanced breeding lines as well as commercial improved varieties. Amongst released varieties e.g. Mahsuri, Muda, Manik, MR 211 and MR 219, mutation breeding had been attempted directly on them for single trait improvements. Generally, induced mutations have yielded mutants which are either used directly or have some interesting and desirable traits for use in further cross breeding. Such mutants include Mahsuri Mutant, Muda 2, PS 1297 and Manik 817, MA03, SPM 29 and SPM 39, Q 34, MRQ 50, SPM 129, SPM 130 and SPM 142. The objectives of this paper are to describe some of these rice mutants which have been developed through mutation breeding until the present time, and also to highlight some of the current activities involving induced mutations. (author)

  12. 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.

  13. Characterization of ultraviolet light-induced ouabain-resistant mutations in Chinese hamster cells

    International Nuclear Information System (INIS)

    Ouabain-resistant mutations in Chinese hamster cells have been quantitatively characterized. The mutation frequencies were found to be induced curvilinearly with treatments of increasing doses of ultraviolet light (UV). For the range of UV doses tested (5-20 J/m2), the observed mutation frequency, Y, as a function of UV dose X, follows a curvilinear function, Y=(-28+13.37X - 1.52X2+0.08 X3).10-6. The frequencies of UV-induced mutations were directly correlated with cell survival, indicating a similar causal relationship between cell killing and mutation induction. Under the same experimental conditions, X-rays induced 6-thioguanine-, but not ouabain-, resistant mutations, UV-induced ouabain-resistant (ouasup(r)) mutants exhibit a selection disadvantage. Their phenotypic expressions are modifiable by various agents. Wild type and 16 ouasup(r) mutants were compared with respect to their sensitivity to ouabain inhibition of 86Rb uptake by whole cells. All the ouasup(r) mutants assayed are less sensitive to the drug than are wild-type cells. In the absence of ouabain, the Na+-K+-ATPase activities can be significantly higher or lower than that of the wild-type cells. (Auth.)

  14. Characterization of beta-thalassemia mutations in patients from the state of Rio Grande do Norte, Brazil

    Directory of Open Access Journals (Sweden)

    Zama Messala Luna da Silveira

    2011-01-01

    Full Text Available 35 unrelated individuals were studied for characterization as either heterozygous or homozygous for beta-thalassemia. Molecular analysis was done by PCR/RFLP to detect the mutations most commonly associated with beta-thalassemia (β0IVS-I-1, β+IVS-I-6, and β039. In the patients who showed none of these mutations, the beta-globin genes were sequenced. Of the 31 heterozygous patients, 13 (41.9% had the β+IVS-I-6 mutation, 15 (48.4% the β0IVS-I-1 mutation, 2 (6.5% the β+IVS-I-110 mutation and 1 (3.2% the β+IVS-I-5 mutation. IVS-I-6 was detected in the four homozygotes. The mutation in codon 39, often found in previous studies in Brazil, was not detected in the present case. This is the first study aiming at identifying mutations that determine beta-thalassemia in the state of Rio Grande do Norte.

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

    International Nuclear Information System (INIS)

    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

  16. Irradiation-induced mutation experiments with eiploid and tetraploid tomato plants

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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 5/10000M1 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

  18. Radiation-induced forward and reverse specific locus mutations and dominant cataract mutations in treated strain BALB/c and DBA/2 male mice

    International Nuclear Information System (INIS)

    In the present experiments the genotype of the X-irradiated male mouse was varied. Males were mated to untreated, standard Test-stock females. Mutagenic effects were determined for treated stem cell spermatogonia. Since stem cell spermatogonia are repair competent, should genetic variability in the DNA repair processes exist it would be evident in the induced mutation rates. Based upon the above-mentioned sensitivity to induced killing, reduction in female fecundity, dominant lethal mutation frequency and unscheduled DNA synthesis, strain BALB/c was chosen as sensitive to radiation-induced mutagenesis and strain DBA/2 was chosen as repair competent. The mutation rates to recessive specific locus and dominant cataract alleles were determined. Additionally, employing treated BALB/c and DBA/2 male mice allowed, for the first time, the determination of the radiation-induced reverse mutation rate at 4 specific loci. Results indicate no effect of genotype on the radiation-induced forward mutation rate at the specific loci, although a possibly higher radiation induced mutation rate to dominant cataract alleles was observed in treated DBA/2 mice as compared to treated BALB/c or (101/E1 x C3H/E1)F1 mice but these results require confirmation, and the reverse mutation rate at the a and d loci following paternal irradiation was higher than the spontaneous frequency. (Auth.)

  19. Study on the technique of inducing mutation breeding in chrysanthemum

    International Nuclear Information System (INIS)

    Technique of mutation breeding in chrysanthemum was studied by means of 60Co-γ irradiation and tissue culture. The results showed that radiosensitivity varies greatly with different varieties of chrysanthemum; the suitable doses are 2∼3 krad for radical buds, cutting boughs and the whole plants, and 0.8∼1.0 krad for callus from cultures in vitro. Tissue culture has an advantage over cottage in isolation of mutant mosaics. Mutation rates of flowers of regenerated plants from in vitro culture of VM0, VM1, VM2 are 66.7%, 56.3% and 38.5% respectively, all of which are higher than that from irradiated plants. Practice of breeding 14 new chrysanthemum varieties proved that by combination technique of irradiation with tissue culture, a higher breeding efficiency and shorter period of breeding was achieved

  20. Induced mutations for resistance to powdery mildew in wheat

    International Nuclear Information System (INIS)

    The most serious diseases of wheat in the Yangtze River Valley in China are powdery mildew and scab. Breeding for disease resistance either using conventional methods or through mutation breeding is the best way of controlling these diseases. Mutation breeding may be valuable in obtaining genotypes with resistance or tolerance, or for breaking undesirable linkages involving existing genes for disease resistance. The following commercial varieties were used: Yangmai 3, Ningmai 3 and Ningmai 6. They are high-yielding varieties, but susceptible to powdery mildew. Seeds of these cultivars were treated with gamma-rays. The material was screened in the seedling stage in M2 in the greenhouse and under field conditions in M3-M4 and later generations. The seedlings were inoculated with a spore suspension of the powdery mildew fungus. The most resistant mutant selected from variety Ningmai 3 was the line 34080 with resistance to races 4, 16 and 20. According to the number of progenies in M2, the mutation frequency was 1.2x10-4. The other two mutants (34157, 34158) were screened from variety Yangmai 3. Mutant 34157 showed a stable resistance to races 4, 16 and 20; mutant 34158 was resistant to races 4 and 20 but susceptible to race 16. Tracing them back to M2 progeny, the mutation frequency was 1.0x10-4. From electrophoretic analysis of mildew resistant mutant lines of wheat we found that the zymogram of peroxidase in resistant lines 34080 and 34157 was different from their parents and that these lines do not have band 3A

  1. Space environment induced mutations prefer to occur at polymorphic sites of rice genomes

    Science.gov (United States)

    Li, Y.; Liu, M.; Cheng, Z.; Sun, Y.

    To explore the genomic characteristics of rice mutants induced by space environment, space-induced mutants 971-5, 972-4, and R955, which acquired new traits after space flight such as increased yield, reduced resistance to rice blast, and semi-dwarfism compared with their on-ground controls, 971ck, 972ck, and Bing95-503, respectively, together with other 8 japonica and 3 indica rice varieties, 17 in total, were analyzed by amplified fragment length polymorphism (AFLP) method. We chose 16 AFLP primer-pairs which generated a total of 1251 sites, of which 745 (59.6%) were polymorphic over all the genotypes. With the 16 pairs of primer combinations, 54 space-induced mutation sites were observed in 971-5, 86 in 972-4, and 5 in R955 compared to their controls, and the mutation rates were 4.3%, 6.9% and 0.4%, respectively. Interestingly, 75.9%, 84.9% and 100% of the mutation sites identified in 971-5, 972-4, and R955 occurred in polymorphic sites. This result suggests that the space environment preferentially induced mutations at polymorphic sites in rice genomes and might share a common mechanism with other types of mutagens. It also implies that polymorphic sites in genomes are potential "hotspots" for mutations induced by the space environment.

  2. Recovery of induced mutations for X chromosome-linked muscular dystrophy in mice.

    OpenAIRE

    Chapman, V M; Miller, D R; Armstrong, D; Caskey, C. T.

    1989-01-01

    We have used elevated levels of plasma creatine phosphokinase activity to identify muscular dystrophy phenotypes in mice and to screen the progeny of chemical mutagen-treated male mice for X chromosome-linked muscular dystrophy mutations. We were not successful in identifying heterozygous carriers of these induced muscular dystrophy mutations in greater than 8000 progeny. However, we were highly successful in identifying three additional alleles of the characterized mdx locus. These alleles o...

  3. Patterns of Repeat-Induced Point Mutation in Transposable Elements of Basidiomycete Fungi

    OpenAIRE

    Horns, Felix; Petit, Elsa; Yockteng, Roxana; Hood, Michael E.

    2012-01-01

    Transposable elements (TEs) are ubiquitous genomic parasites that have prompted the evolution of genome defense systems that restrict their activity. Repeat-induced point mutation (RIP) is a homology-dependent genome defense that introduces C-to-T transition mutations in duplicated DNA sequences and is thought to control the proliferation of selfish repetitive DNA. Here, we determine the taxonomic distribution of hypermutation patterns indicative of RIP among basidiomycetes. We quantify C-to-...

  4. Modification of radiation-induced sex-linked recessive lethal mutation frequency by tocopherol

    International Nuclear Information System (INIS)

    The present study evaluates the effect of supplementing culture medium with α-tocopherol acetate on the yield of sex-linked recessive lethal mutants induced by X-irradiation in mature sperm of Drosophila. Although tocopherol treatment of males had no impact on the yield of mutations, a drastic reduction in mutation frequency was observed when irradiated males were mated to females raised and subsequently maintained on tocopherol-enriched diet. (orig./MG)

  5. Helicobacter pylori induces mitochondrial DNA mutation and reactive oxygen species level in AGS cells

    OpenAIRE

    Xue-Wen Huang, Rui-Hua Luo, Qi Zhao, Zhong-Ze Shen, Li-Li Huang, Xian-Yuan An, Lan-Jing Zhao, Jie Wang, Yu-Zheng Huang

    2011-01-01

    To investigate the role of ROS in the helicobacter pylori (Hp) induced mtDNA mutations, AGS cells were treated by extracts of Hp11638 or Hp11638M. The ROS levels, cytochrome C reductions, and intracellular ATP levels were measured. The coding region and the D-Loop region were amplified and sequenced. Results showed the ROS levels, cytochrome C reduction and mtDNA mutations were markedly increased and cell viability decreased after treatment with both Hp extracts, and 616 mutations were detect...

  6. Factors affecting mutational specificity induced by ionizing radiation and oxidizing radicals

    International Nuclear Information System (INIS)

    We propose to analyze the factors affecting the specificity of mutational change as induced by ionizing radiation and oxidizing radicals. We want to understand not only the rules that affect base substitution, but also the mechanism(s) by which additions and deletions are produced, since detections are a common consequence of radiation. We wish to carry out this analysis in an in vitro mutation system that permits us to analyze the role of base sequence, of polymerase and of mutagenic agent. Our system is designed to screen out most direct breaks as a cause of mutation and should indicate the changes resulting from base damage to the DNA

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

    Science.gov (United States)

    Toki, Hideaki; Minowa, Osamu; Inoue, Maki; Motegi, Hiromi; Karashima, Yuko; Ikeda, Ami; Kaneda, Hideki; Sakuraba, Yoshiyuki; Saiki, Yuriko; Wakana, Shigeharu; Suzuki, Hiroshi; Gondo, Yoichi; Shiroishi, Toshihiko; Noda, Tetsuo

    2016-08-01

    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(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. PMID:27131742

  8. Beta-Globin Gene Regulation and Nuclear Organisation

    NARCIS (Netherlands)

    J.A. Kooren (Jurgen)

    2007-01-01

    textabstractAll genetic information required for the development and functioning of an organism is stored in billions of base pairs of deoxyribonucleic acid (or DNA). In eukaryotes, DNA is organised in large units called chromosomes that are located inside the cells nucleus. On these chromosomes res

  9. Inducing mutations in the mouse genome with the chemical mutagen ethylnitrosourea

    Directory of Open Access Journals (Sweden)

    S.M.G. Massironi

    2006-09-01

    Full Text Available When compared to other model organisms whose genome is sequenced, the number of mutations identified in the mouse appears extremely reduced and this situation seriously hampers our understanding of mammalian gene function(s. Another important consequence of this shortage is that a majority of human genetic diseases still await an animal model. To improve the situation, two strategies are currently used: the first makes use of embryonic stem cells, in which one can induce knockout mutations almost at will; the second consists of a genome-wide random chemical mutagenesis, followed by screening for mutant phenotypes and subsequent identification of the genetic alteration(s. Several projects are now in progress making use of one or the other of these strategies. Here, we report an original effort where we mutagenized BALB/c males, with the mutagen ethylnitrosourea. Offspring of these males were screened for dominant mutations and a three-generation breeding protocol was set to recover recessive mutations. Eleven mutations were identified (one dominant and ten recessives. Three of these mutations are new alleles (Otop1mlh, Foxn1sepe and probably rodador at loci where mutations have already been reported, while 4 are new and original alleles (carc, eqlb, frqz, and Sacc. This result indicates that the mouse genome, as expected, is far from being saturated with mutations. More mutations would certainly be discovered using more sophisticated phenotyping protocols. Seven of the 11 new mutant alleles induced in our experiment have been localized on the genetic map as a first step towards positional cloning.

  10. Characteristics and inheritance of space flight induced mutations in rice genomes

    Science.gov (United States)

    Cheng, Zhenlong; Feng, Jie; Kong, Fanding; Wang, Chunli; Zhang, Meng; Jinming Shi, Mrs; Guan, Shuanghong; Sun, Yeqing

    In order to determine the mutagenic effects of space flight and the properties of space induced mutations, the seeds of 5 japonica rice varieties, Zhenzhuhong, Lianjing-2, Yuguang, Beijinghong and Lianjing-1, were carried on-board by Shenzhou-6 spaceship for 5-day-flight. In M1 generation, 20-30 individuals were selected at random from each variety for determination of genomic changes with AFLP method. Sixteen pairs of selective amplification primers were used and 1061, 933, 1054, 749, and 673 loci were detected in each variety. Mutation rates were 3.4% 10.1%, 3.3% 8.5%, 4.0% 10.1%, 0.93% 6.54% and 1.19% 4.46%. Three individuals with significant phenotypic changes which in significant differences in height, tillering, length of spike, seeds per spike and per individual, the mutation rates were 13.7%, 12.1% and 13.1% respectively,. These results suggested that space flight induced mutations in rice genomes and the phenotypic mutants showed higher genomic mutation rates. Nineteen mutant loci were amplified for sequence analysis. BlastN program performance showed that 10 (52.6%) were matched with sequences in GenBank, 5 single copies and 5 multi-copies in rice genome. Among 5 single copy sequences, 2 were located at exons, 2 at introns. One was combined with exon and intron sequences. Three multi-copy sequences were related to transposons or retroposon, one of which was combination of two fragments in different chromosomes, indicating that chromosome recombination may be involved in spaceflight induced mutation. Inheritance of one mutation at transposon related region and another mutation at non-coding region was checked in M1, 2 and 3 generations. Results showed that mutation loci can be inherited to some but all progenies. Interestingly, mutations were detected in M3 individuals, whose M2 parents were with no mutation at corresponding loci, suggesting that space flight may induce genomic instability on rice seeds (Supported by National Natural Science Foundation No

  11. Study on toxicity mutation of crownvetch induced by radiation

    International Nuclear Information System (INIS)

    The suckers of Germany crownvetch were irradiated by 60Co gamma-ray and fast neutron. The toxicity mutation frequency and genetic stability of crownvetch were studied. The various toxicity mutants were found in M1. Most of the toxicity mutants was unstable in M2. Stable mutant was very few (about 2.0-12.9%). Beta-nitropropionic acid in the low toxicity mutants selected was 31.7-39.8 mg/g, genetic characteristics of low toxicity mutants were stable in M3-M5

  12. Improvement of bambara groundnut production using induced mutations

    International Nuclear Information System (INIS)

    Induction of variation in bambara groundnut using gamma radiation has been tried before. However, no mutants with the desired determinate flowering habit and synchronous pod maturity were obtained. This project is aimed at: conducting a nationwide exploration exercise to collect germplasm of bambara groundnut for agronomic evaluation with respect to flowering and fruiting characteristics and their effects on yield; and, applying the technique of mutation induction to create variability (if this is not found in the germplasm to be collected) from which mutants with determinate flowering and fruiting habit may be selected for use in breeding. 6 refs

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

    International Nuclear Information System (INIS)

    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/m2. 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

  14. Nature of induced mutations affecting disease reaction in wheat

    International Nuclear Information System (INIS)

    Three genes, Lr20, Sr15 and Pml conferring resistance to some strains of Puccinia recondita, P. graminis tritici and Erysiphe graminis tritici, respectively, have never been observed to undergo genetic recombination. Since genotypes possessing one of the alleles always possessed the other two, the hypothesis of one gene with pleiotropic effects was tested. Seeds of a homozygous line possessing the gene(s) in coupling with a recessive chlorophyll marker, cn-Ala, were treated with three levels of EMS. Very high rates of mutation were observed. Changes with respect to Pml were independent of changes with respect to Lr20 and Sr15 indicating molecular independence of the product of the Pml allele. On the other hand, all instances of change with respect to Lr20 were associated with changes of Sr15. With both Lr20 and Sr15 a range of variation in infection types produced by the mutant lines was established but the rankings of the degree of change monitored by the respective pathogens were not identical. It is suggested that the same host gene product is recognized by the products of the avirulence alleles of the two rust pathogens. Screening with virulent counterparts of the three pathogens failed to detect instances of obvious mutations producing new resistances. The results are considered in relation to the gene-for-gene hypothesis. (author)

  15. Spectrum of Glycidyl Methacrylate—induced Mutation in Plasmid—Escherichia coli System

    Institute of Scientific and Technical Information of China (English)

    GAOHui-Lan; ZuoJin; 等

    1994-01-01

    In order to characterize the spectrum of mutation induced by glycidyl methacrylate(GMA),the plasmid pBR322 was modified with this mutagen in vitro.transfected into appropriate Escherichia coli host HB101.The mutants were then screned and defined by DNA sequencing.Sequence analysis reveals that GMA induces two classes of mutations:deletion of the mono-,di-or tetra-base or the insertion of mono-or di-base.Both types of muations,with about 10% frequency,occur predominantly at C.G runs and at 5'-CNCCN-3' sequence,which are hotspots for GMA damage and may cause frameshift muation.

  16. Complex Human Glucocorticoid Receptor dim Mutations Define Glucocorticoid Induced Apoptotic Resistance in Bone Cells

    OpenAIRE

    Jewell, Christine M.; Scoltock, Alyson B.; Hamel, Brant L.; Yudt, Matthew R.; Cidlowski, John A.

    2011-01-01

    A mutation in the D-loop of the second zinc finger of the DNA-binding domain of the human glucocorticoid receptor (hGR), A458T (GRdim), has been suggested to be essential for dimerization and DNA binding of the GR, and genetically altered GRdim mice survive, whereas murine GR knockout mice die. Interestingly, thymocytes isolated from the GRdim mice were reported to be resistant to glucocorticoid-induced apoptosis. To further evaluate the dim mutations in glucocorticoid-induced apoptosis, we s...

  17. Molecular genetic analysis of regions of the murine genome associated with radiation-induced mutations

    International Nuclear Information System (INIS)

    The authors are exploiting the large array of radiation-induced mutations to develop both detailed molecular and functional maps of selected small model regions (as opposed to specific genes) within the mouse genome. Through the integrated use of recombinant DNA technology and classical genetic and cytogenetic analysis, they hope to relate the structure and function of these regions to the study of both normal and abnormal mammalian development. Over the years, the germ-line mutagenesis program has generated a valuable array of induced mutations at several specific loci scattered throughout the murine genome. Many of these mutations are multilocus deletions of chromosomal DNA. Genetic analysis of these types of lesions has detected passenger mutations of wide-ranging effect and severity, and has generated gross functional maps of entire chromosomal regions. They have initiated a program to expand the molecular analysis of these types of deletion mutations. This program exploits the deletion mutations and other chromosomal rearrangements to obtain molecular clones of wild-type DNA that map to regions absent in mutants carrying the deletions. These clones will then be used to correlate the resultant molecular/physical map of the chromosomal region with the genetic/functional map in both mutant and wild-type individuals. Such correlations are essential to a strategy for identifying as many of the genes as possible in a particular region of the genome and for ascertaining their role(s) in the normal development of the mouse

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

    Science.gov (United States)

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

    2013-07-01

    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.

  19. Induction of spontaneous and UV-induced mutations during commitment to meiosis in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Inductions of reversions of nonsense, missense and frameshift-type mutations were investigated in a diploid cell population of Saccharomyces cerevisiae during commitment to meiosis, by using the medium-transfer technique from sporulation medium to vegetative medium. The yields of spontaneous reverse mutations obtained from the cells that were committed to different stages during meiosis were rather constant irrespective of the alleles tested, although the yields of both intergenic and intragenic recombinations markedly increased. The susceptibilities to UV-induced reverse mutations examined during commitment to meiosis were not changed appreciably. It is concluded that induction of base-change-type mutations in meiosis is not essentially different from that in mitosis. (orig.)

  20. Analysis of human transforming growth factor β-induced gene mutation in corneal dystrophy

    Institute of Scientific and Technical Information of China (English)

    李杨; 孙旭光; 任慧媛; 董冰; 王智群; 孙秀英

    2004-01-01

    Background Corneal dystrophy is a group of inherited blinding diseases of the cornea. This study was to identify the mutations of the keratoepithelin (KE) gene for proper diagnosis of corneal dystrophy. Methods Three families with corneal dystrophy were analysed. Thirteen individuals at risk for corneal dystrophy in family A, the proband and her son in family B, and the proband in family C were examined after their blood samples were obtained. Mutation screening of human transforming growth factor β-induced gene (BIGH3 gene) was performed. Results Five individuals in family A were found by clinical evaluation to be affected with granular corneal dystrophy and carried the BIGH3 mutation W555R. However, both probands in families B and C, also diagnosed with granular corneal dystrophy, harboured the BIGH3 mutation R124H. Conclusion Molecular genetic analysis can improve accurate diagnosis of corneal dystrophy.

  1. Development of improved cotton cultivars by induced mutations

    International Nuclear Information System (INIS)

    Seeds of two superior Greek varieties namely Sindos 80 and 4S were irradiated with gamma-rays (100, 200 and 300 Gy) in order to create new genetic variation and consequently to develop lines resistant to Verticillium wilt. LD50 was found to be around 300 Gy for the two varieties. The treated seeds of both varieties along with the control were sown in 1992. From the two varieties used, 6,000 plants were obtained, some showing morphological differences compared to the control. M2 seeds of 400 plants of M1 generation were sown in small pots and placed in growth chambers. From these M2 seedlings 0.23 - 0.24% in both varieties were albino and about the same percentage were viridis. This gives an indication of the expected mutation frequency for other characters in the same genetic background. (author). 2 refs, 3 tabs

  2. Genetic improvement of rice (oryza sativa l.) by induced mutations

    International Nuclear Information System (INIS)

    In 1989 was initiated at Rice Research Institute of Cuba, a mutation breeding programme, in order to obtain new germoplasm with improved characters such as milling quality, earliness, resistance to the Hoja Blanca virus disease and salt tolerance. Seven varieties has been irradiated and two different sources of radiation were used: gamma rays from 60Co and fast neutrons of a 14 MeV neutron generator. In 1995, was released the variety IACuba 23 for low inputs conditions. Another four varieties IACuba 21, IACuba 22, IACuba 27 and IACuba 28 are in validation trials in rice production areas under irrigated condition. The last two have showed resistance to Steneotarsonemus spinki. Also, a group of mutants was selected to be used as parents. These mutants have been used in 953 crosses

  3. Induced mutations in Iraqi bread wheat cv. Saber Beg

    International Nuclear Information System (INIS)

    ''Saber Beg'', is a local wheat cultivar important in the semi-arid zone of Iraq where the rainfall is less than 450 mm per year. This cultivar has a good baking quality, but is of low productivity, high susceptibility to common bunt (Tilletia spp.) and to leaf rust (Puccinia recondita Rob. ex Desm.), but only in the rainy season. A mutation breeding programme using gamma irradiation has been started in 1978 to improve this cultivar. Seeds of all main tillers from M1 plants were harvested and artificially inoculated with teliospores of Tilletia spp. All the seeds from healthy M2 plants were inoculated again and sown in the same area. Out of 22920 M3 plants, 244 resistant ones were selected. During subsequent screening for 4 generations, however, only 3 mutants were confirmed

  4. Improvement of quinoa and barley through induced mutations and biotechnology

    International Nuclear Information System (INIS)

    The main cropping problems in the Bolivian highlands are the long growing period of barley, high degree of environmental influence on the performance of quinoa, and low soil moisture at sowing time, leading to low germination rate and poor stands, and frost or chilling damages. The program aimed to establish protocols for induction of mutations with X rays and chemical mutagens (NaN3, MNH, EMS) in quinoa, barley, native forage species and forest plants and to obtain mutant lines, especially in barley and quinoa; and to establish callus regeneration in quinoa and micropropagation of kenua (Polilepis). The project is still in its study stages, hence further evaluations are needed before firm conclusions are drawn. (author)

  5. Obtaining induced mutations of drought tolerance in sorghum

    International Nuclear Information System (INIS)

    Since sorghum plant (Sorghum bicolor L.) has a big potential to be cultivated in Indonesia especially in drought-prone areas, improvement of sorghum had been carried out through mutation breeding methods. The seeds of the sorghum plant was irradiated by gamma rays emitted from cobalt-60 source. The total dose was 0.4 kGy. Through selection process in the M2 generation, a number of promising mutant lines of sorghum have been obtained and registered in the M3 generation. In the M4, a number of 100 mutant lines were tested against drought in Gunung Kidul District during the dry season in 2000. Results of the test showed that mutant line DU/20/Psj/1, DU/20/Psj/4, DU/20/Psj/24, JA/30/Cty/21, ET/40/Psj/4 and DU/20/Psj/10 had relatively high grain yield compared to the control variety. (author)

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

    International Nuclear Information System (INIS)

    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

  7. Induced mutations for protein quantity and quality in wheat

    International Nuclear Information System (INIS)

    One of the main objectives of the genetic improvement programme in Argentina is to obtain wheat cultivars with a larger protein content and good nutritive qualities. Artificial induction of mutations is used to obtain genetic variability in agronomically desirable forms. The size and weight of the grains show a positive and highly significant correlation with the amount of protein formed in them. Thus the selection of genotypes differing from the original variety can be based on mutations affecting these characters, which have the advantage of being easily measurable. In this way we have obtained the following variants of practical value: (1) A mutant with shorter seeds in cv. Sinvalocho wheat. This has a smaller amount of protein in the grain and a smaller proportion of the gliadin fraction. As a consequence, the other protein fractions show a relative increase and the proportion of amino acid lysine rises by about 15% in the protein. Four years of experimentation have made it possible to study annual variations in the expression of this character, and the gene or genes which control it have been localized. (2) Mutants with increased protein content in Magnif 41 wheat. This variety is in itself a good expression of high relative protein content in the grain. Nevertheless, it has been possible to isolate particular variants in which the percentage of protein is further enhanced by 4 to 5 points by selecting grains of increased weight. The conclusion is that if we succeed in obtaining a coherent system of selection for wheat, it will be possible to detect useful variants differing from the original line. For this purpose it should be borne in mind that small seeds facilitate the selection of forms with a larger lysine content (low gliadin), and large seeds facilitate the selection of forms with an enhanced protein content. (author)

  8. Induced mutation-facilitated genetic studies of seed phosphorus

    International Nuclear Information System (INIS)

    Both the chemical composition and total amount of seed phosphorus (P) are important to the end-use quality of cereal and legume seed crops, whether for use in human foods or animal feeds. They are also important to the management of P in agricultural production, and to the long-term sustainability of that production. About 75% (±10%) of seed total P is found as phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate). Mutations that block the synthesis or accumulation of phytic acid during seed development, often referred to as low phytic acid (lpa) mutations, have been isolated in maize (Zea mays L.), barley (Hordeum vulgare L.), rice (Oryza sativa L.), wheat (Triticum aestivum L.) and soybean (Glycine max L. (Merr.). Chromosomal mapping has identified as many as six non-allelic lpa loci in a single species (barley). Studies of lpa mutants has enhanced knowledge of the genes and proteins important to phytic acid P metabolism. While there has been substantial research into the biology of P uptake by plants, there has been little progress in the genetics of seed total P. Genetics that either decreases or increases seed total P might be of value for both enhancing the end-use quality of seed crops and for optimizing the utilization of P during agricultural production. As proof-of-principle, homozygosity for recessive alleles of barley lpa1 both blocks seed phytic acid accumulation by 50% and reduces seed total P by 15%, while having little impact on yield. The current status of lpa genetics and current efforts at isolating 'seed-total P' mutants, using both forward and reverse genetics approaches, will be described. (author)

  9. Induced Mutation-Facilitated Genetic Studies of Seed Phosphorus

    International Nuclear Information System (INIS)

    Both the chemical composition and total amount of seed phosphorus (P) are important to the end-use quality of cereal and legume seed crops, whether for use in human foods or animal feeds. They are also important to the management of P in agricultural production, and to the long-term sustainability of that production. About 75% (±10%) of seed total P is found as phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate). Mutations that block the synthesis or accumulation of phytic acid during seed development, often referred to as low phytic acid (lpa) mutations, have been isolated in maize (Zea mays L.), barley (Hordeum vulgare L.), rice (Oryza sativa L.), wheat (Triticum aestivum L.) and soybean (Glycine max L. (Merr.). Chromosomal mapping has identified as many as six non-allelic lpa loci in a single species (barley). Studies of lpa mutants has enhanced knowledge of the genes and proteins important to phytic acid P metabolism. While there has been substantial research into the biology of P uptake by plants, there has been little progress in the genetics of seed total P. Genetic factors that either decrease or increase seed total P might be of value for both enhancing the end-use quality of seed crops and for optimizing the utilization of P during agricultural production. As proof-of-principle, homozygosity for recessive alleles of barley lpa 1 both blocks seed phytic acid accumulation by 50% and reduces seed total P by 15%, while having little impact on yield. The current status of lpa genetics and current efforts at isolating 'seed-total P' mutants, using both forward and reverse genetics approaches, will be described. (author)

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

    International Nuclear Information System (INIS)

    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

  11. Induced mutations for genetic analyses and improvement of wheat

    International Nuclear Information System (INIS)

    Induced mutants affecting spike density proved useful for demonstrating that milling properties are genetically controlled independently of spike density and the characteristic grain shape associated with club (T. aestivum ssp. compactum) wheats. Induced semidwarf height mutants can be exploited for extending genetic knowledge of allelic relations and interactions in wheat as well as for broadening the genetic base of height control in breeding high-yielding semidwarf wheats. The degree of dominance shown by different mutants varies from completely recessive, through degrees of partial dominance to the apparently complete dominance as indicated by one mutant now undergoing extensive tests. No common wheat induced mutant so far tested either duplicates or is allelic to known spontaneous mutants for reduced height, but only a few have been located in the genome or tested for allelism. One mutant shows dominance in crosses with the original variety, but partial dominance in other combinations. Undesirable/desirable traits often appear to be associated with induced mutant semidwarfs, but these differ from those undesirable/desirable traits associated with the widely tested spontaneous semidwarfing sources. One induced mutant semidwarf durum from Washington State University research shows promise for direct exploitation as a privately registered cultivar in France. Mutants induced in einkorn wheat (T. monococcum L.) have extended the spectrum of genetic variation known in this species. One of these new mutant forms resembles an uncommon mutant in barley, and may be useful for homoeologous chromosome identification

  12. Use of gamma radiation in floriculture industry for development of new varieties through induced mutation

    International Nuclear Information System (INIS)

    Nuclear radiation (gamma rays) can create changes in genetic make up of plant material through mutation. Gamma ray induced mutation is now an established method for crop improvement. It is well known that the crops which are propagated vegetatively are very suitable for the application of mutation breeding methods. In floriculture industry there is always demand and necessity of new and novel ornamental varieties. Flower colour and shape are the most important components of novelties. Gamma rays have been most successfully use to produce quite a large number of new promising,varieties in different ornamental (Bougainvillea - 4, Perennial portulaca-6, Chrysanthemum-43, Hibiscus-1, Rose-16, Tuberose-2, Lantana depressa-3 etc.) plants by bringing about genetic changes at Floriculture Section, National Botanical Research. Institute, Lucknow, India. Research carried out covers radiosensitivity, selection of materials, methods of exposure to gamma rays, suitable dose of gamma rays, detection of mutants, isolation of mutants and commercial exploitation of mutants. A good number of mutant varieties have been well accepted in the floriculture industry. The mutant varieties are with new flower colour and shape. More than three decades of applied mutation breeding work has now established beyond doubt that mutation breeding will constitute an excellent supplement to the conventional methods for development of new varieties . Detection of somatic, mutations in flower colour/shape in different vegetative generations (M1V1, M1V2, M1V3 and even in later vegetative generations), mutation frequency and spectrum relationship with dose of gamma radiation have been precisely determined. Studies have clearly proved that mutation breeding technique can be exploited for the creation of new and novel ornamental cultivars of commercial importance by inducing genetic variation in already adapted, modern genotypes and can also enrich the germplasm of ornamental horticulture. (Author)

  13. Practical value of induced mutations for disease resistance in wheat, triticum aestivum

    International Nuclear Information System (INIS)

    The potential of induced mutations in wheat are studied relative to conventional breeding efforts. A total of 134 lines with improved resistance to diseases such as Erysiphe graminis, Puccinia striiformis, Puccinia graminis or Puccinia recondita were found in frequencies betweeen 0,000-0,061 per 100 M2 plants during the last 15 years. The frequency of mutants that could be utilized in a breeding programme is lower than the total frequency of useful mutations. The majority of mutants has undergone additional undesirable changes. Some of these mutants segregate permanently. However, some mutants were also obtained which differ from a parent line in an almost entirely positive way. Examples of such mutants are given and indicate that the induced mutation method can be an efficient tool in breeding for disease resistance

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  17. Factors impeding the application of induced mutation techniques for plant breeding in Africa

    International Nuclear Information System (INIS)

    The use of induced mutants in plant breeding is a fairly recent innovation but the number of improved cultivars and genetic variants resulting from the application of this breeding technique is steadily increasing. In Africa, there has been very little effort in this field. It has long been known that induced mutations could be useful for the solution of specific problems where more conventional breed methods were insufficient. This has been demonstrated in rice, wheat barley and many ornamentals. In future mutation breeding may indeed become essential for further yield, and quality .improvement in some agro-ecological zones, particularly for the major cereals, where the breeding intensity has been very great. Interest in the use of induced mutations for crop improvement in Africa started in the early seventies. The coordinated seed protein improvement programme organized by the FAO/IAEA joint division contributed greatly to the participation of African scientists in the induced mutations breeding programme. Some promising results are already apparent with rice, soybean, beans and cowpeas in East Africa and West Africa

  18. Ionizing radiation-induced mutation of human cells with different DNA repair capacities

    International Nuclear Information System (INIS)

    We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by α-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and α-particles. WTK1 is also more mutable by α-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while α-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-induced tk- mutants of TK6, were not induced significantly by α-particles. Previously, we showed that TK6 has a reduced capacity for recombination compared with WTK1, and therefore, these results indicate that recombinational repair may contribute to both cell survival and mutation-induction following exposure to ionizing radiation. Such a mechanism may aid cell survival, but could also result in increased deleterious effects such as the unmasking of recessive mutations in cancer suppresser genes

  19. The variation of D-loop in mitochondrial genome and the mutation induced by irradiation

    International Nuclear Information System (INIS)

    As the non-code region of mitochondrial genome, the displacement-loop region (D-loop) controls the replication and transcription of mtDNA, but it is easy to be altered. The variation, including mutation and polymorphism, plays an important role in disease. Finally, the status quo of radiation induced D-loop variation and its perspective were outlined. (authors)

  20. Ionizing radiation-induced mutation of human cells with different DNA repair capacities

    Energy Technology Data Exchange (ETDEWEB)

    Amundson, S.A.; Chen, D.J.

    1994-12-31

    We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by {alpha}-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and {alpha}-particles. WTK1 is also more mutable by {alpha}-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while {alpha}-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-induced tk- mutants of TK6, were not induced significantly by {alpha}-particles. Previously, we showed that TK6 has a reduced capacity for recombination compared with WTK1, and therefore, these results indicate that recombinational repair may contribute to both cell survival and mutation-induction following exposure to ionizing radiation. Such a mechanism may aid cell survival, but could also result in increased deleterious effects such as the unmasking of recessive mutations in cancer suppresser genes.

  1. Utilization of induced mutations for groundnut breeding in Uganda

    International Nuclear Information System (INIS)

    Groundnuts (Arachis hypogaea L.) are on high demand in Uganda. There is, therefore, an urgent need to improve groundnut yields through breeding. The main objectives besides yield are the following: 1. To improve disease resistance: (a) rosette virus transmitted by aphids (Aphis craccivora); (b) leafspot caused by Cercospora arachidicola (early) and Cercosporidium personatum (late). 2. To advance the maturity period of high yielding varieties so as to fit better into the rainfall pattern of the main growing areas. 3. To improve seed uniformity, seed size and quality (protein, oil). 4. To reduce plant height by shortening the internodes so as to have more flower production near the ground. For mutation breeding three erect groundnut cultivars were used, Roxo a recommended commercial variety; Red Beauty (Bl) a recommended local variety and No. 534 a tan skinned variety. Seeds of the three varieties were irradiated in 1976 at the FAO/IAEA Agricultural Section of the IAEA Laboratory Seibersdorf, with 1500 rad of fast neutrons (Nf) or 20 krad of 60Co gamma rays. The pedigree method of selection was used until M9. During 1985 and 1986, seven mutant selections of Red Beauty and one from Roxo were tested in replicated yield trials. Results are given. On the basis of plot yields some of the Red Beauty mutant lines outyielded the parent but not the commercial variety Roxo

  2. Utilization of induced mutations in groundnuts in Uganda

    International Nuclear Information System (INIS)

    Three cultivars of groundnut (Arachis hypogaea L.) were treated with two different types of ionizing radiation. These were gamma rays, at a dose of 20 krad, and fast neutrons, at a dose of 1500 rad, irradiating mature seeds. Several mutants were obtained from the treated material. Major visible changes observed included an increased number of branches per plant, increase/reduction in plant size, change in stem colour, change in plant growth habit and improvement in seed quality. Chlorophyll mutations were also observed and the affected albino plants died within two weeks of germination. Change in flower colour, from normal yellow to white, was observed in the M3 generation involving 37 plants. Mutants showing beneficial characters, such as high pod yield, good pod and seed quality, early maturity and disease resistance, were selected. Single plant selection was carried out up to the ninth generation, when preliminary yield trials (replicated) commenced for the more promising mutant lines. Results for eight mutants and the two original parents are given for one season. (author). 15 refs, 4 tabs

  3. Mutator activity induced by microRNA-155 (miR-155) links inflammation and cancer.

    Science.gov (United States)

    Tili, Esmerina; Michaille, Jean-Jacques; Wernicke, Dorothee; Alder, Hansjuerg; Costinean, Stefan; Volinia, Stefano; Croce, Carlo M

    2011-03-22

    Infection-driven inflammation has been implicated in the pathogenesis of ~15-20% of human tumors. Expression of microRNA-155 (miR-155) is elevated during innate immune response and autoimmune disorders as well as in various malignancies. However, the molecular mechanisms providing miR-155 with its oncogenic properties remain unclear. We examined the effects of miR-155 overexpression and proinflammatory environment on the frequency of spontaneous hypoxanthine phosphoribosyltransferase (HPRT) mutations that can be detected based on the resistance to 6-thioguanine. Both miR-155 overexpression and inflammatory environment increased the frequency of HPRT mutations and down-regulated WEE1 (WEE1 homolog-S. pombe), a kinase that blocks cell-cycle progression. The increased frequency of HPRT mutation was only modestly attributable to defects in mismatch repair machinery. This result suggests that miR-155 enhances the mutation rate by simultaneously targeting different genes that suppress mutations and decreasing the efficiency of DNA safeguard mechanisms by targeting of cell-cycle regulators such as WEE1. By simultaneously targeting tumor suppressor genes and inducing a mutator phenotype, miR-155 may allow the selection of gene alterations required for tumor development and progression. Hence, we anticipate that the development of drugs reducing endogenous miR-155 levels might be key in the treatment of inflammation-related cancers. PMID:21383199

  4. Dominant cataract mutations induced by γ-irradiation of male mice

    International Nuclear Information System (INIS)

    To improve the knowledge of the phenotypic damage caused by mutational events occurring in the first generation the authors initiated an experiment to study the induction of radiation-induced hereditary cataracts. To determine the frequency of dominant mutations affecting the lens, the authors examine the offspring of irradiated and control (101xC3H)F1 hybrid male mice which had been mated to untreated females. The observation of the induction of specific-locus mutations served as a positive control of the effectiveness of the exposure. The males of the irradiated group were exposed at the age of 11 weeks to 455 R+455 R 137Cs γ-rays (55 R/min) with a 24-h fractionation interval. The eyes of the F1 offspring, as well as of the animals of the parental generation, were examined biomicroscopically. The F1 offspring were 3 weeks old at the time of examination. The frequency of specific-locus mutations (9 mutations in 5231 offspring) derived from irradiated spermatogonia was 2.7x10-7 mutations/locus/R in this experiment, which is in accord with data discussed elsewhere. (Auth.)

  5. Compensatory variances of drug-induced hepatitis B virus YMDD mutations.

    Science.gov (United States)

    Cai, Ying; Wang, Ning; Wu, Xiaomei; Zheng, Kai; Li, Yan

    2016-01-01

    Although the drug-induced mutations of HBV have been ever documented, the evolutionary mechanism is still obscure. To deeply reveal molecular characters of HBV evolution under the special condition, here we made a comprehensive investigation of the molecular variation of the 3432 wild-type sequences and 439 YMDD variants from HBV genotype A, B, C and D, and evaluated the co-variant patterns and the frequency distribution in the different YMDD mutation types and genotypes, by using the naïve Bayes classification algorithm and the complete induction method based on the comparative sequence analysis. The data showed different compensatory changes followed by the rtM204I/V. Although occurrence of the YMDD mutation itself was not related to the HBV genotypes, the subsequence co-variant patterns were related to the YMDD variant types and HBV genotypes. From the hierarchy view, we clarified that historical mutations, drug-induced mutation and compensatory variances, and displayed an inter-conditioned relationship of amino acid variances during multiple evolutionary processes. This study extends the understanding of the polymorphism and fitness of viral protein. PMID:27588233

  6. Current status and outlook perspectives of induced mutations for plant improvement

    International Nuclear Information System (INIS)

    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)

  7. PROTS-RF: a robust model for predicting mutation-induced protein stability changes.

    Directory of Open Access Journals (Sweden)

    Yunqi Li

    Full Text Available The ability to improve protein thermostability via protein engineering is of great scientific interest and also has significant practical value. In this report we present PROTS-RF, a robust model based on the Random Forest algorithm capable of predicting thermostability changes induced by not only single-, but also double- or multiple-point mutations. The model is built using 41 features including evolutionary information, secondary structure, solvent accessibility and a set of fragment-based features. It achieves accuracies of 0.799,0.782, 0.787, and areas under receiver operating characteristic (ROC curves of 0.873, 0.868 and 0.862 for single-, double- and multiple- point mutation datasets, respectively. Contrary to previous suggestions, our results clearly demonstrate that a robust predictive model trained for predicting single point mutation induced thermostability changes can be capable of predicting double and multiple point mutations. It also shows high levels of robustness in the tests using hypothetical reverse mutations. We demonstrate that testing datasets created based on physical principles can be highly useful for testing the robustness of predictive models.

  8. Induced short culm mutations in local quality rice cultivar

    International Nuclear Information System (INIS)

    Mushqa Budji a local quality rice cultivar (land race) adapted to cool and temperate agro-climatic conditions of Kashmir valley possesses fairly good degree of tolerance to low temperatures during seedling and grain filling stages of growth (stages when day/night temperatures are usually very low). The cultivar is grown in some localized areas of valley under transplanted-irrigated rice production ecosystem. The cultivar is low yielding but it has aromatic bold grains and good cooking qualities. This variety has a good potential for export to South East Asian countries and domestic markets. The present investigations were, therefore, undertaken to induce genetic variability in the cultivar using gamma rays and ethyl methane sulphonate as mutagens. In the present paper morphology and initial performance of the two induced dwarf mutants is presented

  9. The improvement of cisantana rice variety through induced mutation

    International Nuclear Information System (INIS)

    The continuous improvement for rice through breeding is necessary to obtain new varieties with good quality and quantity. Cisantana variety hairy tips could be improved by mutation breeding. Seeds of Cisantana variety was irradiated by gamma rays (60Co) at doses of 0.10, 0.20 and 0.30 kGy respectively at the Center for Application of Isotope and Radiation (CAIR) - Batan, Pasar Jumat, Jakarta. There after the irradiated seeds were planted as M1 plants at the CAIR’S experiment field in the dry season of 2000. Selection was carried out at the M2 generation and stressed on early maturity and bald spike. This was done at the experiment field at Pusakanegara - Subang in the Wet season of 2001/2002. From this population 19 mutants having early maturity and bald spike lets were selected. Purification in the next generation obtained 10 mutants which were homogeneous and without segregation. From these 10 mutants two mutant lines Obs-1688/PsJ and Obs-1692/PsJ were further tested. These two mutant lines showed good productivity and adaptability when tested at several locations. The resistance test for brown plant hopper and bacterial leaf blight disease showed that these two mutant lines are resistant to biotype 1 and 2, and medium resistant to biotype 3 of brown plant hopper, and also resistant to strain 3 and medium resistant to strain IV of bacterial leaf blight disease. These two mutant lines have good rice quality and were gelatinous. The Obs-1688/PsJ and Obs-1692/PsJ mutant lines were released as new rice varieties by the Minister of Agriculture and officially address as Mira-1 at 2006 and Bestari at 2008, respectively. (author)

  10. Induced mutations for disease resistance in wheat and field beans

    International Nuclear Information System (INIS)

    Wheat disease in Egypt is reviewed and results of mutation breeding by γ irradiation for disease resistance in wheat and field beans are described. Wheat mutants of the variety Giza 155 resistant to leaf rust, Giza 156 resistant to both leaf and yellow rusts, and Tosson with a reasonable level of combined resistance to the three rusts in addition to mutants of the tetraploid variety Dakar 52 with a good level of stem and yellow rust resistance are required. Their seeds were subjected to 10, 15 and 20 krad. Of 3000-3700 M2 plants from each variety and dosage, 22 plants from both Giza 155 and Giza 156, although susceptible, showed a lower level of disease development. In 1975, M3 families of these selected plants and 6000 plants from bulked material were grown from each variety and dosage at two locations. Simultaneously, an additional population consisting of 3000 mutagen-treated seeds was grown to have a reasonable chance of detecting mutants; 2 heads from each plant were harvested. These will be grown next season (1976) to make a population of 25,000-30,000 M2 plants and screened to composite cultures of specific rusts. Vicia faba seeds of field bean varieties Giza 1, Giza 2 and Rebaya 40, equally susceptible to rust and chocolate spot, were subjected to 3, 5 and 7 krad of 60Co gamma radiation and 800 M1 plants were grown in 1972 per variety and dose. Up to this later growing season (M3) no resistance was detected in M3 plank

  11. Somatic mutations in stilbene estrogen-induced Syrian hamster kidney tumors identified by DNA fingerprinting

    Directory of Open Access Journals (Sweden)

    Roy Deodutta

    2004-01-01

    Full Text Available Abstract Kidney tumors from stilbene estrogen (diethylstilbestrol-treated Syrian hamsters were screened for somatic genetic alterations by Random Amplified Polymorphic DNA-polymerase chain-reaction (RAPD-PCR fingerprinting. Fingerprints from tumor tissue were generated by single arbitrary primers and compared with fingerprints for normal tissue from the same animal, as well as normal and tumor tissues from different animals. Sixty one of the arbitrary primers amplified 365 loci that contain approximately 476 kbp of the hamster genome. Among these amplified DNA fragments, 44 loci exhibited either qualitative or quantitative differences between the tumor tissues and normal kidney tissues. RAPD-PCR loci showing decreased and increased intensities in tumor tissue DNA relative to control DNA indicate that loci have undergone allelic losses and gains, respectively, in the stilbene estrogen-induced tumor cell genome. The presence or absence of the amplified DNA fragments indicate homozygous insertions or deletions in the kidney tumor DNA compared to the age-matched normal kidney tissue DNA. Seven of 44 mutated loci also were present in the kidney tissues adjacent to tumors (free of macroscopic tumors. The presence of mutated loci in uninvolved (non-tumor surrounding tissue adjacent to tumors from stilbene estrogen-treated hamsters suggests that these mutations occurred in the early stages of carcinogenesis. The cloning and sequencing of RAPD amplified loci revealed that one mutated locus had significant sequence similarity with the hamster Cyp1A1 gene. The results show the ability of RAPD-PCR to detect and isolate, in a single step, DNA sequences representing genetic alterations in stilbene estrogen-induced cancer cells, including losses of heterozygosity, and homozygous deletion and insertion mutations. RAPD-PCR provides an alternative molecular approach for studying cancer cytogenetics in stilbene estrogen-induced tumors in humans and experimental

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

    International Nuclear Information System (INIS)

    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

  13. Studies on physically and chemically induced soybean mutations of high protein and oil content and their genetic pattern

    International Nuclear Information System (INIS)

    In 1983, two different varieties were treated with five doses of fast neutrons and two concentrations of ethyl methane-sulphonate (EMS) in order to study the effects of different mutagens on the production of mutations with high protein and oil content. The experiment seems to show that EMS had a better effect in inducing such mutations. It showed not only a large variation in extent, but also a higher frequency of mutations. Fast neutrons could also induce mutations with high protein and oil content, but the rate was lower than for EMS. For high protein and oil content mutations induced by fast neutrons, the correlation between the M2 and M3 generations was unstable; it is difficult to forecast the protein and oil content of subsequent generations from seeds of the M2 generation. The high protein and oil content mutations induced by EMS showed a high hereditary value in the M2 and M3 lines. The values of such parameters as hereditary variation, the hereditary variance coefficient, the hereditary capacity and the genetic advance of high protein content mutations were higher than those for high oil content mutations. Thus, it seems easier to induce mutations with high protein rather than high oil content. (author). 8 refs, 2 figs, 4 tabs

  14. Chromosomal mutations induced by triplex-forming oligonucleotides in mammalian cells.

    OpenAIRE

    Vasquez, K M; Wang, G; Havre, P A; Glazer, P M

    1999-01-01

    Specific recognition of a region of duplex DNA by triplex-forming oligonucleotides (TFOs) provides an attractive strategy for genetic manipulation. Based on this, we have investigated the ability of the triplex-directed approach to induce mutations at a chromosomal locus in living cells. A mouse fibroblast cell line was constructed containing multiple chromosomal copies of the lambdasupFG1 vector carrying the supFG1 mutation-reporter gene. Cells were treated with specific (psoAG30) or control...

  15. New Codanin-1 Gene Mutations in a Italian Patient with Congenital Dyserythropoietic Anemia Type I and Heterozygous Beta-Thalassemia.

    Science.gov (United States)

    D'Alcamo, Elena; Agrigento, V; Pitrolo, L; Sclafani, S; Barone, R; Calvaruso, G; Buffa, V; Maggio, A

    2016-06-01

    Congenital dyserythropoietic anemia type I is an autosomal recessive disorder associated with macrocytic anemia, ineffective erythropoiesis, iron overloading and characterized by abnormal chromatin ultrastructure in erythroblasts such as internuclear chromatin bridges, spongy heterochromatin and invagination of the nuclear membrane. A 58-year-old Causasian man with chronic hemolytic anemia, heterozygous for β (+) -globin IVS1, nt110 G>A mutation (causing abnormal alpha:beta globin chain ratio) showed clinical, laboratory and hematological features suggesting diagnosis of CDA1. Sequence analysis of CDA-related genes revealed compound heterozygosity for two novel mutations in the CDAN1 gene: a frameshift mutation 3367 del 4 (TTAG) in exon 25 and a missense mutation c.1811 G>T in exon 11 causing an aminoacid change from glycine to valine at codon 565 (G565V). One of the propositus' brothers showed the same gene mutations. As the CDA1 can mimic thalassemia, a frequent misdiagnosis is possible especially in countries where the prevalence of thalassemia is high. A strong clinical suspicion in patients who do not reveal a clear genetic basis for presumed thalassemia may help clinch the correct diagnosis. PMID:27408412

  16. 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

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

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. Frequencies of aneuploidy and dominant lethal mutations in young female mice induced by low dose γ-rays

    International Nuclear Information System (INIS)

    Relationship between aneuploidy, dominant lethal mutations and doses in young feral mice induced by low dose γ-rays was examined. The results suggest that the frequencies of aneuploidy of embryos increased at 0.15 Gy, but increases at over 0.50 Gy after irradiation in groups. The frequencies of aneuploidy and dominant lethal mutations increased with increasing doses and fitted linear relationship. This dose-response relationship of trisomic was not significant. The frequency of dominant lethal mutations induced by 60Co γ irradiation is 5.59%. The effect of dominant lethal mutation is higher than that of the aneuploidy

  20. Evolution of improved varieties of sesame through induced mutations

    International Nuclear Information System (INIS)

    the seed as compared to black seeded ones. Combined analysis of variances for seed yield over locations revealed significant differences in the performance of the mutants over their source material. Mutants SM5 and SM7 proved superior in respect to seed and oil yield and other agronomic characters. The mutants were given on farm trials at various locations with two management practices, viz., research management with higher inputs and farmers' management practices with low or no inputs. In both management practices the mutants produced significantly higher yield compared to the source. Significant differences were found in seed yield in mutants/check (G), locations (L), management practices (M) and interaction between (GxL) while the interaction between management and location (MxL) was insignificant. Mutants SM5 and SM7 would be submitted to National Seed Board for registration as commercial high yielding mutant varieties. Some of the promising mutants will be utilized in cross-breeding programmes. The present report discusses the effect of mutagen on sesame genotypes, results obtained in different mutant generation and overall mutation breeding studies carried out throughout the project period starting from 1993 to 1997. (author)

  1. Mutations in bacteria induced by heavy ion irradiation. Final report

    International Nuclear Information System (INIS)

    This report presents an introductory paper which summarizes the contribution of the project work to the current knowledge in the field, and describes the experiments planned to be performed in the near future. The first two sections of the report contain six papers dealing with genetic radiation effects in bacteria, and three papers on theoretical interpretations of radiation-induced mutagenesis, all having been published in radiobiological journals. The next section presents full-text papers of the symposium on ''Radiation Biology and its Application in Space Research'', held in Brno in 1992. The last section contains the papers of the second symposium on ''Radiation Biology and its Application in Space Research'', held in Brno in 1994. (MG)

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

    International Nuclear Information System (INIS)

    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

  3. Transformation and mutation of golden hamster embryo cells induced by low doses of x-rays

    International Nuclear Information System (INIS)

    A new cell system which makes quantitative analysis possible in both mutation and transformation induced by low doses of X-rays was described and the frequencies of both mutation and transformation were compared in relation to DNA repair which takes place in X-irradiated cells. Golden hamster embryo (GHE) cells were employed to show the availability of the system for the efficient detection of both mutants and transformants concomitantly. The mutation frequency of the cell population irradiated with various doses of X-rays was expressed as the ratio of the number of 8-azaguanine resistant colonies to the 105 colonies formed in normal medium. A linear increase in mutation frequency with increasing dose was observed at doses ranging from 100 to 600 rad. There was no significant increase in mutation frequency with doses below 100 rad. On the other hand, the transformation frequency of the cells was expressed as the ratio of the number of the transformed colonies to the total number of colonies counted. A drastic increase in the transformation frequency was observed when cells were irradiated with less than 100 rad of X-rays. DNA repair might be involved in modifying transformation frequency and survivals of GHE cells, and DNA synthesis might be involved in inducing transformation in GHE cells. It seems that the repair of potentially lethal damage taking place in density-inhibited GHE cells within 24 hours after X-irradiation decreases the frequencies of both transformation and mutation. Furthermore, it is evident that the system using GHE cells is sensitive enough to assess the transformational effect of low doses of X-rays. (Namekawa, K.)

  4. Mutagenesis applied to improve fruit trees. Techniques, methods and evaluation of radiation-induced mutations

    International Nuclear Information System (INIS)

    Improvement of fruit tree cultivars is an urgent need for a modern and industrialized horticulture on which is based the economic importance of many countries. Both the cross breeding and the mutation breeding are regarded as the methods to be used for creating new varieties. Research carried out at the CNEN Agriculture Laboratory on mutagenesis to improve vegetatively propagated plants, under the FAO-IAEA Co-ordinated Research Programme, has dealt with methods of exposure, types of radiations, conditions during and after the irradiation, mechanisms of mutation induction, methodology of isolation of somatic mutations and evaluation of radiation-induced mutations in fruit trees. Problems associated with these aspects have been evaluated, which is very important for the more efficient use of radiation in the mutation breeding. Mutants of agronomical importance (plant size reduction, early ripening, fruit colour change, nectarine fruit, self-thinning fruit) have been isolated in cherry, grape, apple, olive and peach and they are ready to be released. (author)

  5. RFLP Analysis of rice semi dwarf mutation induced by high energy argon ion radiation

    International Nuclear Information System (INIS)

    Two Indica rice varieties, Bianpizhan and Xiangzhan, and their semi dwarf mutants induced by high energy argon ion radiation, Ar 10, and Xiang Ar 1, were examined with restriction fragment length polymorphism(RFLP)analysis by using 97 rice single copy genomic clones mapped on 12 chromosomes of molecular genetic map, combined with 5 restriction enzymes.Among the markers screened, 9 detected polymorphism were between Bianpizhan and Ar 10, and 11 detected polymorphism were between Xiangzhan and Xiang Ar 1.Moreover, two or more restriction enzymes could generate RFLP patterns when screened with a given marker for several polymorphic markers. Based on the polymorphic allelic loci, the mutation frequencies were estimated as 5 15% and 6 39% for Ar 10 and Xiang Ar 1 respectively.These results suggested that the nature of mutation on the DNA level was probably large genetic changes rather than point mutation.Genetic analysis and gene tagging of semi dwarf mutation in one of the mutant line, Ar 10, indicated that this mutation was controlled by a major recessive gene, which was preliminary located on chromosome 4. (author)

  6. Plant type improvement of indigenous rice cultivars through induced mutations

    International Nuclear Information System (INIS)

    A high yielding, locally adapted cultivar 'Afaa Mwanza 1/159' of rice (Oryza sativa L.) which is tall and late in maturity, was irradiated with gamma rays at doses of 170, 210 and 250 Gy to shorten plant height and time of maturity. Twelve mutants were selected, and evaluated for yield performance in field trials from M6 to M9 generations. All the mutants were shorter in plant height, and gave higher mean yield than the parent. Correlation coefficient analysis showed that the number of productive tillers, number of panicles per square meter and grain filling in the panicle were important characters which influenced yield. On the other hand, panicle length had negative influence on yield. Cv. 'Supa India' and 'Salama' were also irradiated with doses of 170, 210, 240 Gy gamma rays. Analysis of M2 populations of these cultivars indicated that mutagenesis created a lot of variation in plant height, maturity, spikelet fertility and panicle length. The induced variation shall be useful in selecting desired plant types. (author). 16 refs, 12 tabs

  7. Differential effects of radical scavengers on X-ray-induced mutation and cytotoxicity in human cells

    International Nuclear Information System (INIS)

    The cytotoxic and mutagenic effects of X irradiation on a human lymphoblast cell line were examined in the presence of two radioprotective agents which modulate damage to DNA. The cells were treated with X rays alone or in the presence of either dimethyl sulfoxide or cysteamine. Surviving fraction and mutation to trifluorothymidine resistance (tk locus) and to 6-thioguanine resistance (hgprt locus) were measured. Survival was enhanced when the cells were irradiated in the presence of dimethyl sulfoxide; the D0 rose from 58 to 107 rad. However, at both genetic loci the induced mutant fractions were identical in the presence or absence of dimethyl sulfoxide. Survival was enhanced to a greater degree when the cells were irradiated in the presence of cysteamine; the D0 rose from 58 to 200 rad. Cysteamine also protected the cells from X-ray-induced mutation; the frequencies of X-ray-induced mutation at both the tk and hgprt loci were reduced by 50-75%. No protective effects were observed unless dimethyl sulfoxide or cysteamine was present during irradiation. These findings are discussed in terms of the hypothesis that, unlike for cell killing, radiation-induced mutagenesis in human lymphoblast cells is not mediated by the actions of aqueous free radicals, but rather by the direct effects of ionizing radiation

  8. Point Mutations in Centromeric Histone Induce Post-zygotic Incompatibility and Uniparental Inheritance.

    Science.gov (United States)

    Kuppu, Sundaram; Tan, Ek Han; Nguyen, Hanh; Rodgers, Andrea; Comai, Luca; Chan, Simon W L; Britt, Anne B

    2015-09-01

    The centromeric histone 3 variant (CENH3, aka CENP-A) is essential for the segregation of sister chromatids during mitosis and meiosis. To better define CENH3 functional constraints, we complemented a null allele in Arabidopsis with a variety of mutant alleles, each inducing a single amino acid change in conserved residues of the histone fold domain. Many of these transgenic missense lines displayed wild-type growth and fertility on self-pollination, but exhibited frequent post-zygotic death and uniparental inheritance when crossed with wild-type plants. The failure of centromeres marked by these missense mutation in the histone fold domain of CENH3 reproduces the genome elimination syndromes described with chimeric CENH3 and CENH3 from diverged species. Additionally, evidence that a single point mutation is sufficient to generate a haploid inducer provide a simple one-step method for the identification of non-transgenic haploid inducers in existing mutagenized collections of crop species. As proof of the extreme simplicity of this approach to create haploid-inducing lines, we performed an in silico search for previously identified point mutations in CENH3 and identified an Arabidopsis line carrying the A86V substitution within the histone fold domain. This A87V non-transgenic line, while fully fertile on self-pollination, produced postzygotic death and uniparental haploids when crossed to wild type. PMID:26352591

  9. Induced Mutations Unleash the Potentials of Plant Genetic Resources for Food and Agriculture

    Directory of Open Access Journals (Sweden)

    Chikelu Mba

    2013-03-01

    Full Text Available The options for increasing food production by at least 70% over the next four decades so as to keep pace with a rapidly increasing human population are bedeviled by erratic climatic conditions, depleted arable lands, dwindling water resources and by the significant environmental and health costs for increasing the use of agrochemicals. Enhanced productivities through “smart” crop varieties that yield more with fewer inputs is a viable option. However, the genetic similarities amongst crop varieties—which render entire cropping systems vulnerable to the same stresses—coupled with unvarying parental materials limit the possibilities for uncovering novel alleles of genes and, hence, assembling new gene combinations to break yield plateaux and enhance resilience. Induced mutation unmasks novel alleles that are harnessed to breed superior crop varieties. The historical antecedents, theoretical and practical considerations, and the successes of induced mutations in crop improvement are reviewed along with how induced mutagenesis underpins plant functional genomics. The roles of cell and molecular biology techniques in enhancing the efficiencies for the induction, detection and deployment of mutation events are also reviewed. Also, the integration of phenomics into induced mutagenesis and the use of pre-breeding for facilitating the incorporation of mutants into crop improvement are advocated.

  10. Development of radiation-induced mutation techniques and functional genomics studies

    International Nuclear Information System (INIS)

    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

  11. Nucleic acid template and the risk of a PCR-Induced HIV-1 drug resistance mutation.

    Directory of Open Access Journals (Sweden)

    Vici Varghese

    Full Text Available BACKGROUND: The HIV-1 nucleoside RT inhibitor (NRTI-resistance mutation, K65R confers intermediate to high-level resistance to the NRTIs abacavir, didanosine, emtricitabine, lamivudine, and tenofovir; and low-level resistance to stavudine. Several lines of evidence suggest that K65R is more common in HIV-1 subtype C than subtype B viruses. METHODS AND FINDINGS: We performed ultra-deep pyrosequencing (UDPS and clonal dideoxynucleotide sequencing of plasma virus samples to assess the prevalence of minority K65R variants in subtype B and C viruses from untreated individuals. Although UDPS of plasma samples from 18 subtype C and 27 subtype B viruses showed that a higher proportion of subtype C viruses contain K65R (1.04% vs. 0.25%; p1.5% of UDPS reads. We therefore performed UDPS on clones and site-directed mutants containing subtype B- and C-specific patterns of silent mutations in the conserved KKK motif encompassing RT codons 64 to 66 and found that subtype-specific nucleotide differences were responsible for increased PCR-induced K65R mutation in subtype C viruses. CONCLUSIONS: This study shows that the RT KKK nucleotide template in subtype C viruses can lead to the spurious detection of K65R by highly sensitive PCR-dependent sequencing techniques. However, the study is also consistent with the subtype C nucleotide template being inherently responsible for increased polymerization-induced K65R mutations in vivo.

  12. Useful mutations induced in durum wheat by gametophyte and seed treatments

    International Nuclear Information System (INIS)

    The durum wheat breeding programme aims at improving the local cold tolerant varieties for lodging resistance, higher yield and good grain quality. The Bulgarian durum wheat cv. 233 has been submitted to mutagenic treatment of gametophytes (1,2,3,4 krad, 60Co γ-rays), seeds (10 krad, 60Co γ-rays; 1 krad, fast neutrons; EMS, 1.5% for 20 hrs at 20 deg. and both gametophytes and seeds (2 krad + 10 krad, γ-rays); 2 krad γ-rays + 1 krad, fast neutron; 2 krad, γ-rays + EMS, 1.5%). 2264 M1 plants were harvested and in each plant the spike of the main culm was kept separate from those produced on the later tillers. A higher frequency M1 plant progenies segregating for morphological and semi-dwarf mutations was observed after gametophyte and combined gametophyte and seed irradiation as compared to only seed treatment. Furthermore, after gametophyte irradiation, out of the 131 M1 segregating progenies, 122 were homogenously heterozygous for the induced mutations (non-chimeric) and all the spikes of a plant were carrying the same mutation. Only a very small number were semi-dwarf mutations and they were obtained only after gametophyte irradiation. The induced semi-dwarf mutants are under evaluation for lodging resistance, yield and protein content. They will be used also in the cross-breeding programme

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

    International Nuclear Information System (INIS)

    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 F1 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 M6 line groups derived from the 7M2 plants, revealed that each M2 progenitor plant of each M6 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 M1 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.)

  14. Unravelling signalling circuits regulating tomato root development using induced mutations

    International Nuclear Information System (INIS)

    Plant roots performs multitude of functions such as water, nutrient uptake and anchorage to the soil. The performance of root to carry these functions can be improved by selecting for induced mutants affected in root development and differentiation. We used tomato as a model plant to decipher the mechanisms underlying root differentiation. We screened EMS and γ-radiated tomato M2 seedlings for mutants defective in root development. In this study, we describe unraveling of signaling circuits regulating root development in tomato. We made detailed physiological, genetic and biochemical characterization of tomato root mutants that are affected in nitric oxide (NO) production and auxin transport. It is now recognized that NO is an important gas molecule that has functions and roles in plants comparable to other gaseous plant hormone ethylene. NO has been reported to participate in many physiological phenomena: such as seed germination, resistance to plant pathogens, stomatal movements, and flowering. Although NO plays a paramount role in plant development, little information is available about mechanisms regulating its biosynthesis in plants. We isolated a tomato mutant displaying extremely short root (shr) in seedlings. We observed that in tomato shr mutant overproduction of NO caused shortening of root. We used shr root elongation as a bioassay to analyze signaling pathway regulating NO formation in plants. We show that a pathway very similar to a mammalian signaling pathway regulates NO levels in plants. The transport of auxin in plants involves a very complex network comprising of proteins, which bring the hormone in and out of the cells. The polycotyledon (poc) mutant of tomato shows an enhanced polar transport of auxin (PAT). Analysis of the role of auxin transporters in poc mutant, especially PIN1, responsible for PAT, at the cellular level would be presented (author)

  15. Deficiency of the DNA repair protein nibrin increases the basal but not the radiation induced mutation frequency in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wessendorf, Petra [Institute of Medical and Human Genetics, Charité – Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin (Germany); Vijg, Jan [Albert Einstein College of Medicine, Michael F. Price Center, 1301 Morris Park Avenue, Bronx, NY 10461 (United States); Nussenzweig, André [Laboratory of Genome Integrity, National Cancer Institute, National Institute of Health, 37 Convent Drive, Room 1106, Bethesda, MD 20892 (United States); Digweed, Martin, E-mail: martin.digweed@charite.de [Institute of Medical and Human Genetics, Charité – Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin (Germany)

    2014-11-15

    Highlights: • lacZ mutant frequencies measured in vivo in mouse models of radiosensitive Nijmegen Breakage Syndrome. • Spontaneous mutation frequencies are increased in lymphatic tissue due to Nbn mutation. • Single base transitions, not deletions, dominate the mutation spectrum. • Radiation induced mutation frequencies are not increased due to Nbn mutation. - Abstract: Nibrin (NBN) is a member of a DNA repair complex together with MRE11 and RAD50. The complex is associated particularly with the repair of DNA double strand breaks and with the regulation of cell cycle check points. Hypomorphic mutation of components of the complex leads to human disorders characterised by radiosensitivity and increased tumour occurrence, particularly of the lymphatic system. We have examined here the relationship between DNA damage, mutation frequency and mutation spectrum in vitro and in vivo in mouse models carrying NBN mutations and a lacZ reporter plasmid. We find that NBN mutation leads to increased spontaneous DNA damage in fibroblasts in vitro and high basal mutation rates in lymphatic tissue of mice in vivo. The characteristic mutation spectrum is dominated by single base transitions rather than the deletions and complex rearrangements expected after abortive repair of DNA double strand breaks. We conclude that in the absence of wild type nibrin, the repair of spontaneous errors, presumably arising during DNA replication, makes a major contribution to the basal mutation rate. This applies also to cells heterozygous for an NBN null mutation. Mutation frequencies after irradiation in vivo were not increased in mice with nibrin mutations as might have been expected considering the radiosensitivity of NBS patient cells in vitro. Evidently apoptosis is efficient, even in the absence of wild type nibrin.

  16. Deficiency of the DNA repair protein nibrin increases the basal but not the radiation induced mutation frequency in vivo

    International Nuclear Information System (INIS)

    Highlights: • lacZ mutant frequencies measured in vivo in mouse models of radiosensitive Nijmegen Breakage Syndrome. • Spontaneous mutation frequencies are increased in lymphatic tissue due to Nbn mutation. • Single base transitions, not deletions, dominate the mutation spectrum. • Radiation induced mutation frequencies are not increased due to Nbn mutation. - Abstract: Nibrin (NBN) is a member of a DNA repair complex together with MRE11 and RAD50. The complex is associated particularly with the repair of DNA double strand breaks and with the regulation of cell cycle check points. Hypomorphic mutation of components of the complex leads to human disorders characterised by radiosensitivity and increased tumour occurrence, particularly of the lymphatic system. We have examined here the relationship between DNA damage, mutation frequency and mutation spectrum in vitro and in vivo in mouse models carrying NBN mutations and a lacZ reporter plasmid. We find that NBN mutation leads to increased spontaneous DNA damage in fibroblasts in vitro and high basal mutation rates in lymphatic tissue of mice in vivo. The characteristic mutation spectrum is dominated by single base transitions rather than the deletions and complex rearrangements expected after abortive repair of DNA double strand breaks. We conclude that in the absence of wild type nibrin, the repair of spontaneous errors, presumably arising during DNA replication, makes a major contribution to the basal mutation rate. This applies also to cells heterozygous for an NBN null mutation. Mutation frequencies after irradiation in vivo were not increased in mice with nibrin mutations as might have been expected considering the radiosensitivity of NBS patient cells in vitro. Evidently apoptosis is efficient, even in the absence of wild type nibrin

  17. Induced Pluripotent Stem Cell Generation-Associated Point Mutations Arise during the Initial Stages of the Conversion of These Cells

    Directory of Open Access Journals (Sweden)

    Mayumi Sugiura

    2014-01-01

    Full Text Available A large number of point mutations have been identified in induced pluripotent stem cell (iPSC genomes to date. Whether these mutations are associated with iPSC generation is an important and controversial issue. In this study, we approached this critical issue in different ways, including an assessment of iPSCs versus embryonic stem cells (ESCs, and an investigation of variant allele frequencies and the heterogeneity of point mutations within a single iPSC clone. Through these analyses, we obtained strong evidence that iPSC-generation-associated point mutations occur frequently in a transversion-predominant manner just after the onset of cell lineage conversion. The heterogeneity of the point mutation profiles within an iPSC clone was also revealed and reflects the history of the emergence of each mutation. Further, our results suggest a possible approach for establishing iPSCs with fewer point mutations.

  18. Induced Pluripotent Stem Cell Generation-Associated Point Mutations Arise during the Initial Stages of the Conversion of These Cells

    Science.gov (United States)

    Sugiura, Mayumi; Kasama, Yasuji; Araki, Ryoko; Hoki, Yuko; Sunayama, Misato; Uda, Masahiro; Nakamura, Miki; Ando, Shunsuke; Abe, Masumi

    2014-01-01

    Summary A large number of point mutations have been identified in induced pluripotent stem cell (iPSC) genomes to date. Whether these mutations are associated with iPSC generation is an important and controversial issue. In this study, we approached this critical issue in different ways, including an assessment of iPSCs versus embryonic stem cells (ESCs), and an investigation of variant allele frequencies and the heterogeneity of point mutations within a single iPSC clone. Through these analyses, we obtained strong evidence that iPSC-generation-associated point mutations occur frequently in a transversion-predominant manner just after the onset of cell lineage conversion. The heterogeneity of the point mutation profiles within an iPSC clone was also revealed and reflects the history of the emergence of each mutation. Further, our results suggest a possible approach for establishing iPSCs with fewer point mutations. PMID:24511470

  19. Cap +1 mutation; an unsuspected cause of beta thalassaemia transmission in Pakistan

    Directory of Open Access Journals (Sweden)

    Sadia Usman Babar

    2009-12-01

    Full Text Available Objective: Thalassemia is one of the most common genetic disorders worldwide. Cap +1 mutation which causes ‘silent beta thalassemia’ is present around all ethnic groups of Pakistan. This study was designed to detect the frequency of Cap+1 mutation in Pakistani Population.Materials and Methods: Molecular genetic for Cap+1 beta thalassemic mutation was done by extracting DNA from whole blood by using Genomic DNA Purification Kit (Gentra system USA. Amplification Refractory Mutation System (ARMS primers were designed for detection of normal and mutant DNA.Basic hematological parameters were performed by using automated analyzer (Sysmex KX-21. Cellulose acetate hemoglobin electrophoresis was done by using semi-automated technique (INTERLAB Roma Microtech Series Electrophoresis system 4.23. Results: The frequency of Cap+1 mutation was observed 5% (10/200 in targeted thalassemic families (having patients with beta-thalassemia intermedia while its frequency was observed 2% (12/600 in total thalassemic genes in Pakistani population. Conclusion: Cap+1 (A-C is a silent mutation and it has very minimum effect on beta globin synthesis because of which it produces very less clinical severity and certain important laboratory diagnostic tests like basic hematological parameters and Hb A2 levels are also remain in normal range. Therefore individuals with Cap+1 mutation may produce children with beta-thalassemia intermedia if they marry an individual with beta-thalassemia minor. Cap+1 (A-C mutation is an unsuspected cause of beta thalassemia transmission in Pakistani population. This mutation can identify at molecular level. As this molecular defect is difficult to diagnose in Laboratory with routine laboratory tests because of that it has become a serious hindrance for thalassemia prevention program in Pakistan.

  20. Somatic mutation and recombination induced with reactor thermal neutrons in Drosophila melanogaster

    International Nuclear Information System (INIS)

    The SMART test of Drosophila melanogaster was used to quantify the effect over the somatic mutation and recombination induced by thermal and fast neutrons at the TRIGA Mark III reactor of the ININ at the power of 300 k W for times of 30, 60 and 120 minutes with total equivalent doses respectively of 20.8, 41.6 and 83.2 Sv. A linear relation between the radiation equivalent dose and the frequency of the genetic effects such as mutation and recombination was observed. The obtained results allow to conclude that SMART is a sensitive system to the induced damage by neutrons, so this can be used for studying its biological effects. (Author)

  1. Mutations in BALB mitochondrial DNA induce CCL20 up-regulation promoting tumorigenic phenotypes

    Energy Technology Data Exchange (ETDEWEB)

    Sligh, James [Department of Medicine—Dermatology Division, University of Arizona, Tucson, AZ 857 24 (United States); University of Arizona Cancer Center, Tucson, AZ 85724 (United States); Janda, Jaroslav [University of Arizona Cancer Center, Tucson, AZ 85724 (United States); Jandova, Jana, E-mail: jjandova@email.arizona.edu [Department of Medicine—Dermatology Division, University of Arizona, Tucson, AZ 857 24 (United States); University of Arizona Cancer Center, Tucson, AZ 85724 (United States)

    2014-11-15

    Highlights: • Alterations in mitochondrial DNA are commonly found in various human cancers. • Mutations in BALB mitochondrial DNA induce up-regulation of chemokine CCL20. • Increased growth and motility of mtBALB cells is associated with CCL20 levels. • mtDNA changes in BALB induce in vivo tumor growth through CCL20 up-regulation. • Mutations in mitochondrial DNA play important roles in keratinocyte neoplasia. - Abstract: mtDNA mutations are common in human cancers and are thought to contribute to the process of neoplasia. We examined the role of mtDNA mutations in skin cancer by generating fibroblast cybrids harboring a mutation in the gene encoding the mitochondrial tRNA for arginine. This somatic mutation (9821insA) was previously reported in UV-induced hyperkeratotic skin tumors in hairless mice and confers specific tumorigenic phenotypes to mutant cybrids. Microarray analysis revealed and RT-PCR along with Western blot analysis confirmed the up-regulation of CCL20 and its receptor CCR6 in mtBALB haplotype containing the mt-Tr 9821insA allele compared to wild type mtB6 haplotype. Based on reported role of CCL20 in cancer progression we examined whether the hyper-proliferation and enhanced motility of mtBALB haplotype would be associated with CCL20 levels. Treatment of both genotypes with recombinant CCL20 (rmCCL20) resulted in enhanced growth and motility of mtB6 cybrids. Furthermore, the acquired somatic alteration increased the in vivo tumor growth of mtBALB cybrids through the up-regulation of CCL20 since neutralizing antibody significantly decreased in vivo tumor growth of these cells; and tumors from anti-CCL20 treated mice injected with mtBALB cybrids showed significantly decreased CCL20 levels. When rmCCL20 or mtBALB cybrids were used as chemotactic stimuli, mtB6 cybrids showed increased motility while anti-CCL20 antibody decreased the migration and in vivo tumor growth of mtBALB cybrids. Moreover, the inhibitors of MAPK signaling and NF

  2. Mutations in BALB mitochondrial DNA induce CCL20 up-regulation promoting tumorigenic phenotypes

    International Nuclear Information System (INIS)

    Highlights: • Alterations in mitochondrial DNA are commonly found in various human cancers. • Mutations in BALB mitochondrial DNA induce up-regulation of chemokine CCL20. • Increased growth and motility of mtBALB cells is associated with CCL20 levels. • mtDNA changes in BALB induce in vivo tumor growth through CCL20 up-regulation. • Mutations in mitochondrial DNA play important roles in keratinocyte neoplasia. - Abstract: mtDNA mutations are common in human cancers and are thought to contribute to the process of neoplasia. We examined the role of mtDNA mutations in skin cancer by generating fibroblast cybrids harboring a mutation in the gene encoding the mitochondrial tRNA for arginine. This somatic mutation (9821insA) was previously reported in UV-induced hyperkeratotic skin tumors in hairless mice and confers specific tumorigenic phenotypes to mutant cybrids. Microarray analysis revealed and RT-PCR along with Western blot analysis confirmed the up-regulation of CCL20 and its receptor CCR6 in mtBALB haplotype containing the mt-Tr 9821insA allele compared to wild type mtB6 haplotype. Based on reported role of CCL20 in cancer progression we examined whether the hyper-proliferation and enhanced motility of mtBALB haplotype would be associated with CCL20 levels. Treatment of both genotypes with recombinant CCL20 (rmCCL20) resulted in enhanced growth and motility of mtB6 cybrids. Furthermore, the acquired somatic alteration increased the in vivo tumor growth of mtBALB cybrids through the up-regulation of CCL20 since neutralizing antibody significantly decreased in vivo tumor growth of these cells; and tumors from anti-CCL20 treated mice injected with mtBALB cybrids showed significantly decreased CCL20 levels. When rmCCL20 or mtBALB cybrids were used as chemotactic stimuli, mtB6 cybrids showed increased motility while anti-CCL20 antibody decreased the migration and in vivo tumor growth of mtBALB cybrids. Moreover, the inhibitors of MAPK signaling and NF

  3. Carcinogens induce reversion of the mouse pink-eyed unstable mutation

    OpenAIRE

    Schiestl, Robert H.; Aubrecht, Jiri; Khogali, Fathia; Carls, Nicholas

    1997-01-01

    Deletions and other genome rearrangements are associated with carcinogenesis and inheritable diseases. The pink-eyed unstable (pun) mutation in the mouse is caused by duplication of a 70-kb internal fragment of the p gene. Spontaneous reversion events in homozygous pun/pun mice occur through deletion of a duplicated sequence. Reversion events in premelanocytes in the mouse embryo detected as black spots on the gray fur of the offspring were inducible by the carcinogen x-rays, ethyl methanesul...

  4. Studies on induced mutation and genetics of a yellow seedling mutant in rapeseed

    International Nuclear Information System (INIS)

    A yellow seedling mutant Tt was derived from the progeny of the inbred 3529(B. napus L.) which seeds were jointly treated with fast neutro exposure and chemical inducer of DES. Genetics investigation showed that the yellow seedling character is controlled by one pair of recessive nuclear genes. The mutation character is easily to be introduced into the other rapeseed lines and could be used as a marker character to identify the authenticity of hybrid seeds

  5. Intersex (ix) mutations of Drosophila melanogaster cause nonrandom cell death in genital disc and can induce tumours in genitals in response to decapentaplegic (dppdisk) mutations

    Indian Academy of Sciences (India)

    R. N. chatterjee; P. Chatterjee; S. Kuthe; M. Acharyya-Ari; R. Chatterjee

    2015-06-01

    In Drosophila melanogaster, the intersex (ix) is a terminally positioned gene in somatic sex determination hierarchy and function with the female specific product of double sex (DSXF) to implement female sexual differentiation. The null phenotype of ix is to transform diplo-X individuals into intersexes while leaving haplo-X animals unaffected. This study on the effect of different intersex mutations on genital disc development provides the following major results: (i) similar range of a characteristic array of morphological structures (from almost double sex terminalia to extreme reduction of terminal appendages) was displayed by the terminalia of XX ix1/ix1, XX ix2/ix2 and XX ix5/ix5 individuals; (ii) an increased number of apoptotic cells were found to occur in a localized manner in mature third instar larval genital discs of ix individuals; (iii) ix mutations can induce high frequency of neoplastic tumours in genitals in the presence of decapentaplegic (dppdisk) mutations; and (iv) heteroallelic combinations of dppdisk mutations can also induce tumours in intersex genitals with variable expressivity. On the basis of these findings, we suggest that: (i) loss of function of ix causes massive cell death in both male and female genital primordia of genital discs, resulting phenotype mimicking in male and female characteristics in genitals; and (ii) at the discs, the apoptotic cells persist as ‘undead’ cells that can induce oncogenic transformation in the neighbouring disc cells when dpp signalling is blocked or reduced by dppdisk mutations.

  6. The use of induced mutation in the development of new cultivars in Morocco: achievement and prospects

    International Nuclear Information System (INIS)

    Under the AFRA project RAF5050, induced mutation programme was initiated on wheat, barley and lentils. Results showed that from mutation induced on three ancient varieties (BD 1658, BD 2777 and Karim) we select seven varieties, characterized by reduced growing cycle and short height. These genotypes are under multiplication for quality test. On barley however, results are less promising, since the obtained mutant materiel are less productive due to their lateness, susceptibility to diseases and lodging. On lentils, we obtained three high productive mutants by irradiating the local variety Bakria. We also select one mutant with 20 days later than the mother variety and two mutants resistant to Fusarium. Furthermore, nitrogen fixation studies showed a high ability of two mutants to fix the atmospheric nitrogen, which was evaluated at 10 to 20%. The selected mutants are growing to improve their genetic stability to start multilocation yield trials. Currently and under the extended phase of AFRA project RAF5056, induced mutation concern the safflower, capper and sugar beet. The objective is more oriented on the increasing of the genetic variability of these species. (author)

  7. Some ENU Induced Mutations: A Resource for Functional Genomics in Bread Wheat

    International Nuclear Information System (INIS)

    Induced mutations have been extensively used in the past for crop improvement. More recently a renewed interest in induced mutations has been witnessed due to their utility in functional genomics research. In the present study eight different types of mutations that were induced in common wheat (Triticumaestivum) due to ENU (N-ethylN-nitrosourea) treatment were grouped into four classes (stem mutants, reproductive mutants, leaf mutant and spike mutants). Two of the stem mutants, namely axillary branching and reduced node (1-2), were novel and interesting. In silico studies were conducted using candidate genes that were reported to produce similar mutant phenotypes in other species. We identified six wheat genomic sequences that were considered orthologous to the sequences for branching genes from rice and maize. Similarly, using EST database we identified 11 unigenes which matched a gene responsible for reduction in number of nodes in maize. These sequences that are involved in axillary branching and reduced number of nodes may be used as candidates for further studies of above mutants in bread wheat. (author)

  8. X-ray-induced bystander response reduce spontaneous mutations in V79 cells

    International Nuclear Information System (INIS)

    The potential for carcinogenic risks is increased by radiation-induced bystander responses; these responses are the biological effects in unirradiated cells that receive signals from the neighboring irradiated cells. Bystander responses have attracted attention in modern radiobiology because they are characterized by non-linear responses to low-dose radiation. We used a synchrotron X-ray microbeam irradiation system developed at the Photon Factory, High Energy Accelerator Research Organization, KEK, and showed that nitric oxide (NO)-mediated bystander cell death increased biphasically in a dose-dependent manner. Here, we irradiated five cell nuclei using 10 × 10 µm2 5.35 keV X-ray beams and then measured the mutation frequency at the hypoxanthine-guanosine phosphoribosyl transferase (HPRT) locus in bystander cells. The mutation frequency with the null radiation dose was 2.6 × 10-5 (background level), and the frequency decreased to 5.3 × 10-6 with a dose of approximately 1 Gy (absorbed dose in the nucleus of irradiated cells). At high doses, the mutation frequency returned to the background level. A similar biphasic dose-response effect was observed for bystander cell death. Furthermore, we found that incubation with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), a specific scavenger of NO, suppressed not only the biphasic increase in bystander cell death but also the biphasic reduction in mutation frequency of bystander cells. These results indicate that the increase in bystander cell death involves mechanisms that suppress mutagenesis. This study has thus shown that radiation-induced bystander responses could affect processes that protect the cell against naturally occurring alterations such as mutations. (author)

  9. Induced mutations and their genetic aspects in wheat (Triticum aestivum vulgare)

    International Nuclear Information System (INIS)

    The hexaploid nature of common wheat (Triticum aestivum vulgare) and triplication of the genes allow a great number of primary induced changes to be present and maintained through generations. Induced mutations have been obtained in the morphological characters of the wheat spike, grain character, plant height, disease resistance, and in many other quantitative characters. In some of our experiments these have been followed through 25 generations. The genetic aspects of these changes, their effect on the micro-evolutionary processes in the populations, and their applicability in plant breeding are discussed. (author). 56 refs

  10. Ultaviolet-induced frameshift mutagenesis in Salmonella typhimurium: absence of an effect of mutation frequency decline

    International Nuclear Information System (INIS)

    Enhanced yields of UV-induced back mutants to prototrophy are observed when irradiated cells of the Salmonella typhimurium frameshift strain LT2 hisC3076(R46) are plated on defined medium containing broth (2.5%, v/v) rather than a trace (0.02 μg/ml) of the required nutrient (histidine). This broth effect is not abolished, and is in fact augmented, in an excision-deficient derivative of hisC3076(R46) carrying the uvr-302 mutation. Since similar broth effects on UV-induced base-pair substitution mutagenesis have usually been attributed to inhibition of mutation frequency decline (MFD), and since MFD is in turn thought to reflect the activity of an intact excision-repair system, we sought to determine whether or not UV-induced premutational lesions leading to the production of frameshifts are susceptible to MFD. Results with the doubly auxotrophic strain LT2 hisC3076 leuA150 (pKM101) showed that in a population of cells actually undergoing MFD (as judged by a rapid loss of UV-induced reversions of the base-pair substitution marker (leuA150)), no concomitant loss of UV-induced reversions of the frameshift hisC3076 marker could be detected. (orig.)

  11. Efficient genome-wide detection and cataloging of EMS-induced mutations using exome capture and next-generation sequencing

    Science.gov (United States)

    Chemical mutagenesis efficiently generates phenotypic variation in otherwise homogeneous genetic backgrounds, enabling functional analysis of genes. Advances in mutation detection have brought the utility of induced mutant populations on par with those produced by insertional mutagenesis, but system...

  12. Patterns of repeat-induced point mutation in transposable elements of basidiomycete fungi.

    Science.gov (United States)

    Horns, Felix; Petit, Elsa; Yockteng, Roxana; Hood, Michael E

    2012-01-01

    Transposable elements (TEs) are ubiquitous genomic parasites that have prompted the evolution of genome defense systems that restrict their activity. Repeat-induced point mutation (RIP) is a homology-dependent genome defense that introduces C-to-T transition mutations in duplicated DNA sequences and is thought to control the proliferation of selfish repetitive DNA. Here, we determine the taxonomic distribution of hypermutation patterns indicative of RIP among basidiomycetes. We quantify C-to-T transition mutations in particular di- and trinucleotide target sites for TE-like sequences from nine fungal genomes. We find evidence of RIP-like patterns of hypermutation at TpCpG trinucleotide sites in repetitive sequences from all species of the Pucciniomycotina subphylum of the Basidiomycota, Microbotryum lychnidis-dioicae, Puccinia graminis, Melampsora laricis-populina, and Rhodotorula graminis. In contrast, we do not find evidence for RIP-like hypermutation in four species of the Agaricomycotina and Ustilaginomycotina subphyla of the Basidiomycota. Our results suggest that a RIP-like process and the specific nucleotide context for mutations are conserved within the Pucciniomycotina subphylum. These findings imply that coevolutionary interactions between TEs and a hypermutating genome defense are stable over long evolutionary timescales. PMID:22250128

  13. Application of Induced Mutation by Using Gamma Ray Treatment in Study Breeding for Orchid (Phalaenopsis) Varieties

    International Nuclear Information System (INIS)

    Aim to breed new orchid varieties adapted to climate of Vietnam for domestic use and export, national orchid breeding program has been established for some years. In our study, application of induced mutation by using 60Co. gamma ray treatment was set up to breed new varieties of Phalaenopsis orchid. Different dosages of 60Co. gamma rays were 0, 20, 40, 60, 100 Gy doses with dose rate of 90 Gy/h. Three years after radiation treatment, result showed that the use of 60Co. gamma rays for treatment had conspicuously influenced to growth, mutation frequencies in morphological and physiological traits of Phalaenopsis varieties. Survival rate and growth vigor of treated plants reduced while total variation ratio increased by higher doses. The useful variations were the highest in 20 Gy and next to 40 Gy radiation treatments. In this study, LD50 dose in radiation treatment for Phalaenopsis orchid variety was at dose 40 Gy. Suitable doses in radiation treatment which made wide diversity for Phalaenopsis orchid was at doses 20-40 Gy. At present, selected Phalaenopsis lines are being conducted to research segregating mutated traits, mutation frequencies in inbred Phalaenopsis lines and multiplication of promising mutant lines. (author)

  14. Using BrdU labelling to detect the HPRT gene mutation frequencies induced by γ rays

    International Nuclear Information System (INIS)

    Using BrdU labelling to detect the HPRT gene mutation frequencies (MFs) of a normal adult induced by γ rays of different doses and to analysis the relationship between the HPRT gene MFs and the radiation doses. Blood was drawn via the vein of a normal adult and was equally divided into five groups. The blood was exposed to γ rays with a dose range from 0.0 Gy to 4.0 Gy respectively. After having cultivated the whole blood, the authors got the HPRT gene MFs of the lymphocytes. With the increase of the doses, the MFs of the HPRT gene rose accordingly. The results also showed that there is a linear-square relationship between the doses of the γ ray and the MFs of the HPRT gene. According to the results, the authors may conclude that BrdU labelling method is a quick, simple and relatively sensitive method for detecting the HPRT gene mutations of somatic cells induced by external radiation exposure and HPRT gene mutation may be used as a radiobiological dosimeter

  15. Application of Induced Mutation Techniques in Ghana: Impact, Challenges and the Future

    International Nuclear Information System (INIS)

    Over two decades of application of induced mutation techniques toward crop improvement in Ghana have led to the production of improved mutant varieties in two crops. In cassava (Manihot esculenta Crantz), irradiation of stem cuttings using gamma irradiation resulted in the production of 'Tek bankye,' a mutant variety with high dry matter content (40%) and good poundability from the parental line which was a segregant of a hybrid between the Nigerian landrace Isunikaniyan (ISU) and the breeder's line TMS 4(2)1425, both from IITA, Nigeria. Similarly, irradiation of vegetative buds of 'Amelonado' (P30), 'Trinitario' (K5) and 'Upper Amazon' (T85/799) cocoa varieties resulted in the production of Cocoa Swollen Shoot Virus (CSSV)-resistant mutant variety. Multi-locational on-farm trials of the mutant line indicate significant increases in yield by farmers with no symptoms of the disease. Despite these achievements, application of induced mutation in Ghana has been challenged by low funding, inadequate statistics on small-holder farms, high attrition rate of researchers, low rate of useful mutant regeneration and lack of indicators for early mutant selection. Recent advances in plant breeding, which combine in vitro techniques with mutation induction hold better prospects for generating useful mutants. (author)

  16. Application of induced mutation techniques in Ghana: Impact, challenges and the future

    International Nuclear Information System (INIS)

    Over two decades of application of induced mutation techniques toward crop improvement in Ghana have led to the production of improved mutant varieties in two crops. In cassava (Manihot esculenta Crantz), irradiation of stem cuttings using gamma irradiation resulted in the production of 'Tek bankye', a mutant variety with high dry matter content (40%) and good poundability from the parental line which was a segregant of a hybrid between the Nigerian landrace Isunikaniyan (ISU) and the breeder's line TMS4(2)1425, both from IITA, Nigeria. Similarly, irradiation of vegetative buds of 'Amelonado' (P30), 'Trinitario' (K5) and 'Upper Amazon' (T85/799) cocoa varieties resulted in the production Cocoa Swollen Shoot Virus (CSSV) resistant mutant variety. Multi-locational on-farm trials of the mutant line indicate significant increases in yield by farmers with no symptoms of the disease. Despite these achievements, application of induced mutation in Ghana has been challenged by low funding, inadequate statistics on small holder farms, high attrition rate of researchers, and low rate of useful mutant regeneration and lack of indicators for early mutant selection. Recent advances in plant breeding which combine in vitro techniques with mutation induction hold better prospects for generating useful mutants. Copy right granted to the IAEA. (author)

  17. Stability Test For Sorghum Mutant Lines Derived From Induced Mutations with Gamma-Ray Irradiation

    Directory of Open Access Journals (Sweden)

    S. Human

    2011-12-01

    Full Text Available Sorghum breeding program had been conducted at the Center for the Application of Isotopes and Radiation Technology, BATAN. Plant genetic variability was increased through induced mutations using gamma-ray irradiation. Through selection process in successive generations, some promising mutant lines had been identified to have good agronomic characteristics with high grain yield. These breeding lines were tested in multi location trials and information of the genotypic stability was obtained to meet the requirements for officially varietal release by the Ministry of Agriculture. A total of 11 sorghum lines and varieties consisting of 8 mutant lines derived from induced mutations (B-100, B-95, B-92, B-83, B-76, B-75, B-69 and Zh-30 and 3 control varieties (Durra, UPCA-S1 and Mandau were included in the experiment. All materials were grown in 10 agro-ecologically different locations namely Gunungkidul, Bantul, Citayam, Garut, Lampung, Bogor, Anyer, Karawaci, Cianjur and Subang. In each location, the local adaptability test was conducted by randomized block design with 3 replications. Data of grain yield was used for evaluating genotypic stability using AMMI approach. Results revealed that sorghum mutation breeding had generated 3 mutant lines (B-100, B-76 and Zh-30 exhibiting grain yield significantly higher than the control varieties. These mutant lines were genetically stable in all locations so that they would be recommended for official release as new sorghum varieties to the Ministry of Agriculture

  18. Stability Test For Sorghum Mutant Lines Derived From Induced Mutations with Gamma-Ray Irradiation

    International Nuclear Information System (INIS)

    Sorghum breeding program had been conducted at the Center for the Application of Isotopes and Radiation Technology, BATAN. Plant genetic variability was increased through induced mutations using gamma-ray irradiation. Through selection process in successive generations, some promising mutant lines had been identified to have good agronomic characteristics with high grain yield. These breeding lines were tested in multi location trials and information of the genotypic stability was obtained to meet the requirements for officially varietal release by the Ministry of Agriculture. A total of 11 sorghum lines and varieties consisting of 8 mutant lines derived from induced mutations (B-100, B-95, B-92, B-83, B-76, B-75, B-69 and Zh-30) and 3 control varieties (Durra, UPCA-S1 and Mandau) were included in the experiment. All materials were grown in 10 agro-ecologically different locations namely Gunungkidul, Bantul, Citayam, Garut, Lampung, Bogor, Anyer, Karawaci, Cianjur and Subang. In each location, the local adaptability test was conducted by randomized block design with 3 replications. Data of grain yield was used for evaluating genotypic stability using AMMI approach. Results revealed that sorghum mutation breeding had generated 3 mutant lines (B-100, B-76 and Zh-30) exhibiting grain yield significantly higher than the control varieties. These mutant lines were genetically stable in all locations so that they would be recommended for official release as new sorghum varieties to the Ministry of Agriculture. (author)

  19. Targeted Cytoplasmic Irradiation with Alpha Particles Induces Mutations in Mammalian Cells

    Science.gov (United States)

    Wu, Li-Jun; Randers-Pehrson, Gerhard; Xu, An; Waldren, Charles A.; Geard, Charles R.; Yu, Zengliang; Hei, Tom K.

    1999-04-01

    Ever since x-rays were shown to induce mutation in Drosophila more than 70 years ago, prevailing dogma considered the genotoxic effects of ionizing radiation, such as mutations and carcinogenesis, as being due mostly to direct damage to the nucleus. Although there was indication that alpha particle traversal through cellular cytoplasm was innocuous, the full impact remained unknown. The availability of the microbeam at the Radiological Research Accelerator Facility of Columbia University made it possible to target and irradiate the cytoplasm of individual cells in a highly localized spatial region. By using dual fluorochrome dyes (Hoechst and Nile Red) to locate nucleus and cellular cytoplasm, respectively, thereby avoiding inadvertent traversal of nuclei, we show here that cytoplasmic irradiation is mutagenic at the CD59 (S1) locus of human-hamster hybrid (AL) cells, while inflicting minimal cytotoxicity. The principal class of mutations induced are similar to those of spontaneous origin and are entirely different from those of nuclear irradiation. Furthermore, experiments with radical scavenger and inhibitor of intracellular glutathione indicated that the mutagenicity of cytoplasmic irradiation depends on generation of reactive oxygen species. These findings suggest that cytoplasm is an important target for genotoxic effects of ionizing radiation, particularly radon, the second leading cause of lung cancer in the United States. In addition, cytoplasmic traversal by alpha particles may be more dangerous than nuclear traversal, because the mutagenicity is accomplished by little or no killing of the target cells.

  20. In utero exposure to nanosized carbon black (Printex90) does not induce tandem repeat mutations in female murine germ cells

    DEFF Research Database (Denmark)

    Boisen, Anne Mette Zenner; Shipley, Thomas; Jackson, Petra;

    2013-01-01

    Inhalation of particles has been shown to induce mutations in the male germline in mice following both prenatal and adult exposures in several experiments. In contrast, the effects of particles on female germ cell mutagenesis are not well established. Germline mutations are induced during active...... cell division, which occurs during fetal development in females. We investigated the effects of prenatal exposure to carbon black nanoparticles (CB) on induction of mutations in the female mouse germline during fetal development, spanning the critical developmental stages of oogenesis. Pregnant C57BL/6...... mutation rates in the resulting F2 generation were determined from full pedigrees (mother, father, offspring) of F1 female mice (178 CB-exposed and 258 control F2 offspring). ESTR mutation rates in CB-exposed F2 female offspring were not statistically different from those of F2 female control offspring....

  1. A PCR based protocol for detecting indel mutations induced by TALENs and CRISPR/Cas9 in zebrafish.

    Directory of Open Access Journals (Sweden)

    Chuan Yu

    Full Text Available Genome editing techniques such as the zinc-finger nucleases (ZFNs, transcription activator-like effecter nucleases (TALENs and clustered regularly interspaced short palindromic repeats (CRISPR/CRISPR-associated (Cas system Cas9 can induce efficient DNA double strand breaks (DSBs at the target genomic sequence and result in indel mutations by the error-prone non-homologous end joining (NHEJ DNA repair system. Several methods including sequence specific endonuclease assay, T7E1 assay and high resolution melting curve assay (HRM etc have been developed to detect the efficiency of the induced mutations. However, these assays have some limitations in that they either require specific sequences in the target sites or are unable to generate sequencing-ready mutant DNA fragments or unable to distinguish induced mutations from natural nucleotide polymorphism. Here, we developed a simple PCR-based protocol for detecting indel mutations induced by TALEN and Cas9 in zebrafish. We designed 2 pairs of primers for each target locus, with one putative amplicon extending beyond the putative indel site and the other overlapping it. With these primers, we performed a qPCR assay to efficiently detect the frequencies of newly induced mutations, which was accompanied with a T-vector-based colony analysis to generate single-copy mutant fragment clones for subsequent DNA sequencing. Thus, our work has provided a very simple, efficient and fast assay for detecting induced mutations, which we anticipate will be widely used in the area of genome editing.

  2. A PCR based protocol for detecting indel mutations induced by TALENs and CRISPR/Cas9 in zebrafish.

    Science.gov (United States)

    Yu, Chuan; Zhang, Yaguang; Yao, Shaohua; Wei, Yuquan

    2014-01-01

    Genome editing techniques such as the zinc-finger nucleases (ZFNs), transcription activator-like effecter nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system Cas9 can induce efficient DNA double strand breaks (DSBs) at the target genomic sequence and result in indel mutations by the error-prone non-homologous end joining (NHEJ) DNA repair system. Several methods including sequence specific endonuclease assay, T7E1 assay and high resolution melting curve assay (HRM) etc have been developed to detect the efficiency of the induced mutations. However, these assays have some limitations in that they either require specific sequences in the target sites or are unable to generate sequencing-ready mutant DNA fragments or unable to distinguish induced mutations from natural nucleotide polymorphism. Here, we developed a simple PCR-based protocol for detecting indel mutations induced by TALEN and Cas9 in zebrafish. We designed 2 pairs of primers for each target locus, with one putative amplicon extending beyond the putative indel site and the other overlapping it. With these primers, we performed a qPCR assay to efficiently detect the frequencies of newly induced mutations, which was accompanied with a T-vector-based colony analysis to generate single-copy mutant fragment clones for subsequent DNA sequencing. Thus, our work has provided a very simple, efficient and fast assay for detecting induced mutations, which we anticipate will be widely used in the area of genome editing. PMID:24901507

  3. On the quality of mutations in mammalian cells induced by high LET radiations

    Science.gov (United States)

    Baumstark-Khan, Christa; Rosendahl, Ilja M.; Rink, Hermann

    The deleterious effects of accelerated heavy ions as component of the space radiation environment on living cells are of increasing importance for long duration human space flight activities. The most important aspect of such densely ionizing particle radiation is attributed to the type and quality of biological damage induced by them. This issue is addressed by investigating cell inactivation and mutation induction at the Hprt locus (coding for hypoxanthine-guanine-phosphoribosyl-transferase) of cultured V79 Chinese hamster cells exposed to densely ionizing radiation (accelerated heavy ions with different LETs from oxygen to gold, specific energies ranging from 1.9 to 69.7 MeV/u, corresponding LET values range from 62 to 13,223 keV/μm) and to sparsely ionizing radiation (200 kV X-rays). 30 spontaneous, 40 X-ray induced and 196 heavy ion induced 6-thioguanine resistant Hprt mutant colonies were characterized by Southern technique using the restriction enzymes EcoRI, PstI and BglII and a full length Hprt cDNA probe isolated from the plasmid pHPT12. Restriction patterns of the spontaneous Hprt mutants were indistinguishable from the wild type pattern, as these mutants probably contain only small deletions or even point mutations in the Hprt locus. In contrast, the overall spectrum of heavy ion induced mutations revealed a majority of partial or total deletions of the Hprt gene. With constant particle fluence (3 × 10 6 particles/cm 2) the quality of heavy ion induced mutations in the Hprt locus depends on physical parameters of the beam (atomic number, specific energy, LET). This finding suggests a relationship between the type of DNA damage and track structure. The fraction of mutants with severe deletions in the Hprt locus after exposure to oxygen ions increases from 65% at 60 keV/μm up to a maximum (100%) at 300 keV/μm and declines with higher LET values to 75% at 750 keV/μm. With heavier ions (Ca- and Au-ions) and even higher LET-values this mutant fraction

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

    International Nuclear Information System (INIS)

    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)

  5. 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)

    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

  6. Utilization of induced mutation techniques in rice improvement in the Philippines

    International Nuclear Information System (INIS)

    Rice is one of the most important food crops in the Philippines, as such, efforts have been made consistently to improve the varieties released to the farmers for planting. Both conventional and induced mutation techniques were utilized to solve some of the problems. Varieties with improved qualities, resistance to pests and diseases, reduced height, early maturity and non-photoperiod sensitive were developed using either physical or chemical mutagen. Other methods were also tried to enhance variability like combination of gamma irradiation and biotechnology. Irradiation of F1 seeds was also initiated including the use of mutants in crosses to transfer their improved mutated characters. Promising selections were already tested and six lines from the F1 irradiation out-yielded both C4-63G and IR 1561-288-3, their parents. (author)

  7. Utilization of induced mutation techniques in rice improvement in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Asencion, A.B.; Santos, I.S.; Barrida, A.C.; Medina, F.I.S. III [Philippine Nuclear Research Institute, Atomic Research Center (Philippines)

    2001-03-01

    Rice is one of the most important food crops in the Philippines, as such, efforts have been made consistently to improve the varieties released to the farmers for planting. Both conventional and induced mutation techniques were utilized to solve some of the problems. Varieties with improved qualities, resistance to pests and diseases, reduced height, early maturity and non-photoperiod sensitive were developed using either physical or chemical mutagen. Other methods were also tried to enhance variability like combination of gamma irradiation and biotechnology. Irradiation of F1 seeds was also initiated including the use of mutants in crosses to transfer their improved mutated characters. Promising selections were already tested and six lines from the F1 irradiation out-yielded both C4-63G and IR 1561-288-3, their parents. (author)

  8. Locus control region HS2 point mutations are generally not responsible for elevated fetal hemoglobin expression of sickle cell patients

    Energy Technology Data Exchange (ETDEWEB)

    Gilman, J.G. [Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY (United States); Brinson, E.C.; Milner, P.M. [Medical College of Georgia, Augusta (United States)] [and others

    1994-09-01

    The locus control region (LCR), composed of four hypersensitive sites (HS1-4) 5{prime} of the {epsilon} globin gene, confers strong, copy-number dependent expression on globin genes in transgenic mice. Several {beta}-globin gene cluster haplotypes carry the sickle cell gene, and show variable levels of fetal hemoglobin (Hb F) expression in association with DNA sequence differences in HS2, {gamma} and {beta} globin promoters, and {gamma}IVSII: The Senegal (SEN or No. 3) haplotype generally has high (>10%) Hb F, Benin (BEN or No. 19) has intermediate Hb F (but some low and some high), and Banu (BAN or No. 20) generally has low Hb F. Huisman and colleagues have proposed that `factors produced under conditions of hematopoietic stress, together with genetic determinants on the haplotype-3 like LCR sequences, allow for high level expression of {gamma} globin genes`. We have now used slot blot to screen high Hb F (>9.5%) and low Hb F cases for two of the three HS2 point mutations described by Oener et al. Comparing eight high Hb F BEN/BEN with two low Hb F BEN/BEN, all ten had the BEN mutations considered by Oener et al. to be associated with low Hb F. Comparing three high Hb F BEN/BAN with two low Hb F BEN/BAN, all five were heterozygous at three positions; this is consistent with BEN having G and T and BAN having A at both positions. DNA sequencing of HS2 for BAN, which is generally associated with low HB F, showed that the point mutations at all three positions were those seen in SEN (generally high Hb F); only the AT repeat region showed major differences, confirming results of Huisman and colleagues. Hence, if there is any effect of HS2 of the Senegal sickle cell haplotype in causing elevated Hb F under hematopoietic stress, it must be due to specific variation in the AT repeat region, which Oener et al. have suggested may bind a silencer.

  9. Development of radiation-induced mutation techniques and functional genomics studies

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Sub; Kang, Si Yong; Kim, Jin Baek [KAERI, Daejeon (Korea, Republic of); and others

    2012-01-15

    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{center_dot}structural{center_dot}functional genomics studies for useful traits.

  10. Induced mutation and in vitro culture techniques for the genetic improvement of ornamentals

    International Nuclear Information System (INIS)

    Mutation breeding using cobalt-60 (60Co) gamma radiation coupled with tissue culture techniques is undertaken for genetic improvement of foliage ornamentals (Dracaena sp. and Murraya exotica L.) and cutflowers (Chrysanthemum morifolium and orchids; Vanda sanderiana, Dendrobium Pattaya Beauty and Phalenopsis schilleriana). Gamma radiation (10-30 Gy) induced chlorophyll mutations and several morphological changes in D. sanderiana. For D. godseffiana, irradiated cuttings resulted in reduction of leaf size and chlorophyll mutations. Reduction in height was observed in the M2 generation of Murraya exotica L. irradiated at doses ranging from 10 to 30 Gy. The dwarf Murraya mutant was multiplied through the use of seeds and presently 116 plants are commercially available and are ''test marketed'' to the public. Tissue culture technique was used to induce mutation and as a means of micropropagation in two ornamental crops (orchids and chrysanthemum). Effects of different doses of gamma radiation on callus induction from nodal sections of chrysanthemum grown in Murashige and Skoog's (MS) with naphthalene acetic acid (NAA) and benzyl adenine (BA) were studied. Micropropagation of irradiated and unirradiated chrysanthemum using MS basal medium is presently being studied. Whorling and changes in leaf color were observed at 10 Gy and doubling of leaf growth at the node at 20 Gy for vegetatively generated V3 plant. In orchids, irradiation of immature embryo with gamma rays ranging from 5 to 10 Gy increased the percentage of germination in Dendrobium Pattaya Beauty and P. schilleriana. Protocorms of Vanda sanderiana irradiated at 10 Gy and grown in Knudson C medium developed into plantlets that are bigger and more vigorous than those irradiated at 20 GY and from the control plant. A decrease in seedling height was observed with increasing dose of gamma radiation. (Author)

  11. A rapid method for detection of five known mutations associated with aminoglycoside-induced deafness

    Directory of Open Access Journals (Sweden)

    Greinwald John H

    2009-01-01

    Full Text Available Abstract Background South Africa has one of the highest incidences of multidrug-resistant tuberculosis (MDR-TB in the world. Concomitantly, aminoglycosides are commonly used in this country as a treatment against MDR-TB. To date, at least five mutations are known to confer susceptibility to aminoglycoside-induced hearing loss. The aim of the present study was to develop a rapid screening method to determine whether these mutations are present in the South African population. Methods A multiplex method using the SNaPshot technique was used to screen for five mutations in the MT-RNR1 gene: A1555G, C1494T, T1095C, 961delT+C(n and A827G. A total of 204 South African control samples, comprising 98 Mixed ancestry and 106 Black individuals were screened for the presence of the five mutations. Results A robust, cost-effective method was developed that detected the presence of all five sequence variants simultaneously. In this pilot study, the A1555G mutation was identified at a frequency of 0.9% in the Black control samples. The 961delT+C(n variant was present in 6.6% of the Black controls and 2% of the Mixed ancestry controls. The T1095C, C1494T and A827G variants were not identified in any of the study participants. Conclusion The frequency of 0.9% for the A1555G mutation in the Black population in South Africa is of concern given the high incidence of MDR-TB in this particular ethnic group. Future larger studies are warranted to determine the true frequencies of the aminoglycoside deafness mutations in the general South African population. The high frequencies of the 961delT+C(n variant observed in the controls suggest that this change is a common non-pathogenic polymorphism. This genetic method facilitates the identification of individuals at high risk of developing hearing loss prior to the start of aminoglycoside therapy. This is important in a low-resource country like South Africa where, despite their adverse side-effects, aminoglycosides will

  12. Comparison of surrogate reporter systems for enrichment of cells with mutations induced by genome editors.

    Science.gov (United States)

    He, Zuyong; Shi, Xuan; Liu, Meirui; Sun, Guangjie; Proudfoot, Chris; Whitelaw, C Bruce A; Lillico, Simon G; Chen, Yaosheng

    2016-03-10

    Genome editors are powerful tools that allow modification of the nuclear DNA in eukaryotic cells both in vitro and in vivo. In vitro modified cells are often phenotypically indistinguishable from unmodified cells, hampering their isolation for analysis. Episomal reporters encoding fluorescent proteins can be used for enrichment of modified cells by flow cytometry. Here we compare two surrogate reporters, RGS and SSA, for the enrichment of porcine embryonic fibroblasts containing mutations induced by ZFNs or CRISPR/Cas9. Both systems were effective for enrichment of edited porcine cells with the RGS reporter proving more effective than the SSA reporter. We noted a higher-fold enrichment when editing events were induced by Cas9 compared to those induced by ZFNs, allowing selection at frequencies as high as 70%. PMID:26778541

  13. Molecular alterations underlying the spontaneous and γ-ray-induced point mutations at the white locus of Drosophila Melanogaster

    International Nuclear Information System (INIS)

    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

  14. P63 null mutation protects mouse oocytes from radio-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Livera, G.; Petre-Lazar, B.; Guerquin, M.J.; Trautmann, E.; Coffigny, H.; Habert, R. [CEA, DSV/DRR/SEGG/LDRG, Unit Gametogenesis et Genotoxic, F-92265 Fontenay Aux Roses (France); Univ Paris 07 Denis Diderot, UFR Biol, UMR S 566, F-92265 Fontenay Aux Roses (France); INSERM, U566, F-92265 Fontenay Aux Roses (France)

    2008-07-01

    Female fertility in mammals is determined by the pool of primordial follicles and low doses of radiation induce a major loss of primordial follicles in the ovary. We investigated the expression of p53 and its homologues, p63 and p73, in the normal and irradiated neonatal ovary. p63 was the only member of the p53 family detected in oocyte nucleus. No p63 transcripts or protein were detected in the early foetal ovary. p63 production began in late pachytene-stage oocytes and peaked in diplotene oocytes in mice and humans. The production of p63 was correlated with meiotic DNA double-strand break repair. Only trans-activation (TA) isoforms were present in the ovary, with TAp63 alpha by far the most abundant in terms of mRNA and protein levels. Complete p63 null mutation did not affect normal ovary development. Irradiation rapidly triggered p63 phosphorylation. p63 null mutation prevented the cleavage of caspases-9 and -3 and the follicle loss induced by ionizing radiation. Thus, our results evidence that irradiation-induced depletion of the primordial follicle pool results from the activation of p63 in quiescent oocytes. (authors)

  15. Present status of rice breeding by induced mutations in Taiwan, Republic of China

    International Nuclear Information System (INIS)

    Since 1957, fourteen varieties, including both indica and japonica, have been treated with X-rays, gamma rays, thermal neutrons and EMS for inducing mutations. The objectives are: (1) To obtain erectoid mutants of good lodging resistance from the tall native varieties which can be adapted for intensive culture; (2) To obtain early maturing mutants with at least the same yield as the original variety, so that the multiple cropping system of Taiwan can be easily handled; and (3) To obtain disease-resistant mutants. The results obtained suggest that after a useful gene such as erectoid has been obtained by induced mutation, it can be used immediately. But in general, it will be more useful to combine this character into other genotypic backgrounds by cross-breeding. Henceforth, further breeding must be carried out by cross-breeding. A number of promising lines were selected from induced mutants after being crossed with local varieties and the advanced test of these lines is being carried on at present. (author)

  16. Analysis of mutation induced by radiation in HPRT gene exon 7/8 of rat smooth muscles cells

    International Nuclear Information System (INIS)

    Objective: To investigate the relationship between radiation dose and HPRT gene locus mutation in rat smooth muscle cells, and provide a molecular basis for prevention of blood vessel restenosis after PTCA. Methods: The smooth muscle cells cultured in vitro were irradiated by radionuclide 188Re with different doses. HPRT gene mutation colonies were selected and isolated by 6-thioguanine. Analysis of mutation in exon 7/8 of HPRT gene were accomplished by polymerase chain reaction and single-strand conformation polymorphism. Results: The HPRT gene mutation frequency of rat smooth muscle cells that were irradiated by radionuclide 188Re ranged from 5.5 x 10-6 to 13 x 10-6. Of 91 HPRT gene mutation colonies, 13 contained exon 7/8 deletion and 15 had point mutation. The exon 7/8 mutation frequency was 30.8%. There was significant relationship between radiation dose and mutation frequency of HPRT gene and exon 7/8. Conclusions: The DNA damage and gene mutation induced by radiation was the basis of proliferation inhibition and apoptosis of smooth muscle cells

  17. Somaclonal variation is induced de novo via the tissue culture process: a study quantifying mutated cells in Saintpaulia.

    Directory of Open Access Journals (Sweden)

    Mitsuru Sato

    Full Text Available BACKGROUND: The origin of somaclonal variation has not been questioned previously, i.e., "pre-existing mutations" in explants and "newly induced mutations" arising from the tissue culture process have not been distinguished. This is primarily because there has been no reliable molecular method for estimating or quantifying variation. METHODOLOGY/PRINCIPAL FINDINGS: We adopted a petal-variegated cultivar of Saintpaulia 'Thamires' (Saintpaulia sp. as the model plant. Based on the difference between the pre- and post-transposon excision sequence of the promoter region of flavonoid 3', 5'-hydoroxylase (F3'5'H, we estimated mutated (transposon-excised cell percentages using a quantitative real-time PCR. Mutated cell percentages in leaf laminae used as explants was 4.6 and 2.4% in highly or low variegation flower plants, respectively, although the occurrences of blue color mutants in their regenerants were more than 40%. Preexisting mutated cell percentages in cultured explants were considerably lower than the mutated plant percentage among total regenerants via tissue culture. CONCLUSIONS/SIGNIFICANCE: The estimation of mutated cell percentages became possible using the quantitative real-time PCR. The origins of mutations were successfully distinguished; it was confirmed that somaclonal variations are mainly caused by newly generated mutations arising from tissue culture process.

  18. A novel ENU-induced mutation, peewee, causes dwarfism in the mouse

    OpenAIRE

    Bon-Ryon, Lee; KANO, Kiyoshi; Young, Jay; John, Simon; Nishina, Patsy M.; Naggert, Jurgen K.; Naito,Kunihiko

    2009-01-01

    We identified a novel fertile, autosomal recessive mutation, called peewee and that results in dwarfing, in a region-specific ENU-induced mutagenesis. These mice at litter size were smaller those of other strains. Histological analysis revealed that the major organs appear normal, but abnormalities in cellular proliferation were observed in bone, liver and testis. Haplotype analysis localized the peewee gene to a 3.3-Mb region between D5Mit83 and D5Mit356.3. There are 18 genes in this linkage...

  19. Improvement of Barley and Chenopodium species in the Andean region by induced mutations

    International Nuclear Information System (INIS)

    Experiments on the genetic improvement of barley (H. vulgare), quinoa (Chenopodium quinoa), and canahua (C. pallidicaule) were conducted in the field and greenhouse at the Centro de Investigaciones Nucleares at Viacha, using different concentrations and treatment durations of sodium azide (NaN3) to induce beneficial mutations. Greenhouse tests were conducted to establish the concentration and treatment duration for sodium azide. The treatments were applied and field evaluations were carried out in different generations to improve the germplasm available in the country, particularly in respect to environmental stresses such as frost, hail, and drought, which severely restrict yields. (author). 3 tabs

  20. Induced Mutation on Jatropha (Jatropha Curcas L.) for Improvement of Agronomic Characters Variability

    OpenAIRE

    Ita Dwimahyani; Ishak

    2004-01-01

    Induced mutation can be used for improving quality in term of seed production, oil content in seed and early maturity of Jatropha with the aim for bio_diesel in Indonesia. The doses of 10, 15,20, and 25 Gy of gamma applied to cuttings was able to increase genetic variability in vegetatively propagated plants of Jatropha at M1V1 (mutant-vegetative-1) generation. Selection for desirable trait will be done at M1 V2 (mutant-1 and vegetative-2) generation untill homogenous plants obtained. Gamma r...

  1. Mutagenic efficiency of radiations and chemical mutagens in inducing viable mutations in rice

    International Nuclear Information System (INIS)

    Studies were undertaken to compare the effectiveness and efficiency of radiations (gamma rays and fast neutrons) and chemical mutagens (EMS and NMU) in inducing viable mutations in rice. Radiations were more effective than chemical mutagens, the most effective being fast neutrons. Mutagenic efficiency when estimated on the basis of lethality was higher for radiations but when based on sterility was higher for chemical mutagens. Fast neutrons, more effective than gamma rays, were less efficient. NMU was more effective but less efficient than EMS. (author)

  2. Modeling of induced mutation process in bacterial cells with defects in excision repair system

    International Nuclear Information System (INIS)

    A mathematical model of the UV-induced mutation process in Escherichia coli bacteria cells with defects in uvrA and polA genes has been developed. The model describes in detail the reaction kinetics for excision repair system. The number of mismatches as results from translesion-synthesis is calculated for both wild-type and mutant cells. An effect of temporal modulation for amount of single-stranded DNA during post-replication repair is predicted. A comparison of repair system efficiency is conducted

  3. Molecular nature of X-ray-induced mutations compared with that of spontaneous ones in human c-hprt gene integrated into mammalian chromosomal DNA

    International Nuclear Information System (INIS)

    X-ray-induced mutations were analysed at molecular levels in comparison with spontaneous mutations. Altered sequences were determined tentatively of 30 independent X-ray-induced mutations in a cDNA of the human hprt gene which was integrated into mammalian chromosome as a part of a shuttle vector. Mutations consisted of base substitutions (37 %), frameshifts (27 %), deletions (27 %) and others (10 %). All these mutational events were distributed randomly over the gene without there being hot spots. The spectrum and distribution of X-ray-induced mutations resembled those of spontaneous mutations. Among base substitutions, transversions were predominant and base substitution mutations occurred more at A:T sites than at G:C sites, which is also the case in spontaneous mutations. Most of the frameshift and deletion mutations induced by X-rays, as well as those spontaneously arising, were characterized by the existence of short direct repeats of several identical bases in a row at the sites of the mutations. A slippage misalignment mechanism in replication well accounts for the generation of these classes of mutations. Judging from the data accumulated so far, it can be concluded that X-ray-induced mutations at molecular levels are similar to those spontaneously occurring. (author)

  4. Inactivation and inducible oncogenic mutation of p53 in gene targeted pigs.

    Directory of Open Access Journals (Sweden)

    Simon Leuchs

    Full Text Available Mutation of the tumor suppressor p53 plays a major role in human carcinogenesis. Here we describe gene-targeted porcine mesenchymal stem cells (MSCs and live pigs carrying a latent TP53(R167H mutant allele, orthologous to oncogenic human mutant TP53(R175H and mouse Trp53(R172H, that can be activated by Cre recombination. MSCs carrying the latent TP53(R167H mutant allele were analyzed in vitro. Homozygous cells were p53 deficient, and on continued culture exhibited more rapid proliferation, anchorage independent growth, and resistance to the apoptosis-inducing chemotherapeutic drug doxorubicin, all characteristic of cellular transformation. Cre mediated recombination activated the latent TP53(R167H allele as predicted, and in homozygous cells expressed mutant p53-R167H protein at a level ten-fold greater than wild-type MSCs, consistent with the elevated levels found in human cancer cells. Gene targeted MSCs were used for nuclear transfer and fifteen viable piglets were produced carrying the latent TP53(R167H mutant allele in heterozygous form. These animals will allow study of p53 deficiency and expression of mutant p53-R167H to model human germline, or spontaneous somatic p53 mutation. This work represents the first inactivation and mutation of the gatekeeper tumor suppressor gene TP53 in a non-rodent mammal.

  5. Analysis of esterase isozyme and SSR for mutagenic progenies induced by space mutation in mustard

    International Nuclear Information System (INIS)

    Seeds of five mustard (Brassica juncea Coss) varieties were carried into outer space by 'Shijian No.8' satellite. After five years' consecutive planting and selection, ten relatively stable mutant lines were obtained, which had significant variation in agronomic and economic characters. The mutant lines and their original varieties without space mutation treatment as control were studied by esterase isozyme and SSR analyses. Electrophoresis analysis of esterase isozymes indicated that there were differences between mutant lines and their controls in enzyme types and enzyme activity. Different mustard varieties had different enzymographs, and so did the mutants induced by space mutation, which shows different sensitivity among different mustard varieties. The SSR analysis showed that large differences were found in the SSR loci between mutant lines and their original variety, the variation frequency was between 9.52% and 57.14% with an average frequency of 26.19% for all the mutant lines. Among the mutant SSR loci, about 56.36% showed changes in band number and 43.64% in molecular weight. These results indicated that the ten mutant lines had large genetic difference in phenotype, genomic sequence and gene expression, and the outer space mutation would be an effective method to develop new mustard germplasm and variety. (authors)

  6. Seventy five years of research on induced mutations with special reference to crop improvement in India

    International Nuclear Information System (INIS)

    Mutation research programmes for crop improvement were initiated about seven decades ago, immediately after the discovery of mutagenic effects X-rays on Drosophila by Muller 1927 and barley and maize by Stadler in 1929. During fifties and sixties, several countries including China, India, the Netherlands, USA and Japan took up the task of crop improvement through mutation breeding approaches. By the end of the 20 th century about 2252 mutant varieties of crop plants including cereals, oil seeds, pulses, vegetables, fruits, fibres and ornamentals have been developed and released for cultivation worldwide. More than 60% of the varieties were released after 1985. While 1585 varieties were released as direct mutants, 667 varieties were developed by using mutants in cross breeding. Physical mutagens (X-rays, gamma rays, thermal and fast neutrons) account for the development of about 89% of the total varieties. Gamma rays alone were used to develop about 60% of the mutant varieties. India has made an appreciable contribution with the development of 301 mutant varieties (> 13% ) of forty four crop species. The mutant varieties have been improved for plant architecture, yield, quality and tolerance to biotic and abiotic stresses. Mutation breeding has made a significant contribution to the national economy of the countries like China, India, Japan, Pakistan and USA. Induced mutagenesis is gaining importance in plant molecular biology as a tool to identify and isolate gene and to study their structure and function. (author)

  7. The potential role of biotechnology and induced mutations in plant breeding

    International Nuclear Information System (INIS)

    Although conventional techniques including mutation induction have increased the productivity of crops, the application of biotechnological tools such as tissue culture and molecular markers can speed up crop improvement. Through the application of in vitro culture techniques in Mammilaria san-angelensis, an ornamental cactus severely endangered, we proved through flow cytometry, genetic uniformity in massive in vitro derived plantlets and after irradiation we were able to regenerate it up to M1V4 generation. Solid mutants are expected if somatic embryos are treated with mutagenic agents due to its unicellular origin. Somatic embryogenesis was successfully achieved in Agave tequilana and after irradiation of embryogenic callus cultures, survivors were challenged with pathogenic crude bacterial extracts allowing the selection of resistant or tolerant individuals. Specially important are studies on neglected crops due to the interruption of its domestication and they are locally important for indigenous people as marginal crops. The trend now is to combine biotechnology and induced mutations to overcome problems with this highly promising crops. Chenopodium quinoa exhibits a strong constraint as food due to the undesirable production of saponins. The mutation induction strategy has enabled the reduction of this compounds in M5 generation, but further research is needed to overcome productivity and adaptability problems. Here the use of molecular markers (RAPDS) and flow cytometry techniques acquire relevance in the study of related species such as Chenopodium berlandieri in order to design an inter-specific breeding programme among selected mutants and outstanding local races to combine productivity, adaptability and grain quality

  8. Targeted mutations induced by a single acetylaminofluorene DNA adduct in mammalian cells and bacteria

    International Nuclear Information System (INIS)

    Mutagenic specificity of 2-acetylaminofluorene (AAF) has been established in mammalian cells and several strains of bacteria by using a shuttle plasmid vector containing a single N-(deoxyguanosin-8-yl)acetylaminofluorene (C8-dG-AAF) adduct. The nucleotide sequence of the gene conferring tetracycline resistance was modified by conservative codon replacement so as to accommodate the sequence d(CCTTCGCTAC) flanked by two restriction sites, Bsm I and Xho I. The corresponding synthetic oligodeoxynucleotide underwent reaction with 2-(N-acetoxy-N-acetylamino)-fluorene (AAAF), forming a single dG-AAF adduct. This modified oligodeoxynucleotide was hybridized to its complementary strand and ligated between the Bsm I and Xho I sites of the vector. Plasmids containing the C8-dG-AAF adduct were used to transfect simian virus 40-transformed simian kidney (COS-1) cells and to transform several AB strains of Escherichia coli. Colonies containing mutant plasmides were detected by hybridization to 32P-labeled oligodeoxynucleotides. Presence of the single DNA adduct increased the mutation frequency by 8-fold in both COS cells and E. coli. Over 80% of mutations detected in both systems were targeted and represented G x C → C x G or G x C → T x A transversions or single nucleotide deletions. The authors conclude that modification of a deoxyguanosine residue with AAF preferentially induces mutations targeted at this site when a plasmid containing a single C8-dG-AAF adduct is introduced into mammalian cells or bacteria

  9. Selective Breeding under Saline Stressed Conditions of Canola Mutations Induced by Gamma Rays

    International Nuclear Information System (INIS)

    Mutation breeding program has been initiated for inducing canola mutations tolerance to saline stressed conditions for growing at harsh land in Egypt. Therefore, seed lots of three cultivars and exotic variety (Bactol, Serow 4, Serow 6 and Evita) were subjected to 100,400 and 600 Gy of gamma rays. Mass selection with 20 % intensity for high number of pods per plant has been done in each treatment in M2 generation. However, individually plants with high number of pods / plant were selected from each variety in M3 generation for test under saline stressed conditions at Ras Sudr region in M4 (8600 and 8300 ppm salinity for soil and irrigation, respectively). The obtained results revealed that eight mutated families from 12- test families in M4 generation surpassed their parents in seed yield / plant and related characters ( plant height ,fruiting zone length , No. of branches , No. of pods / plant ). In addition, the mutant F93 characterized by fast growing and non shuttering pods reflecting 50.4% over Evita control in seed yield/ plant. Twelve mutant lines in M5 represented the mutant families were grown in sandy-loam soil at Inshas region. The three mutant lines (L 22, L 38 and L 45) continuously surpassed their parents in seed yield and related characters, but the increases were less than the previous generation. The increase was 22.3 %, 38.7 % and 36.7 % over seed yield of respective parents. Moreover, mutant L66 exhibited an increase in its yield components in M5 at Inshas only, suggesting that gene expression and genomic structure extremely influenced by environmental factors. Genetic stability for the obtained mutations could be done at different environmental conditions in further studies

  10. Mutator transposon activation induced by UV-B in Zea mays

    International Nuclear Information System (INIS)

    The Mutator (MuDR/Mu) DNA transposon family in maize includes diverse elements; they all share similar ∼215 bp Terminal Inverted Repeats (TIRs), but each has unique internal sequences. MuDR is the regulatory element for the entire system, and the presence of transcriptionally active MuDR elements is required for transposition of the nonautonomous Mu elements. MuDR encodes two genes, mudrA and mudrB. mudrA encodes the transposase, MURA, and mudrB encodes a protein with unknown function. In a previous work, we demonstrated that both mudrA and mudrB transcripts are expressed at higher levels after an 8h-UV-B treatment, in both Mutator active and silencing plants. This transcript increase is accompanied by an increase in histone H3 acetylation and by a decrease in DNA and histone H3 methylation. No changes in the siRNAs were detected. To further evaluate the role of UV-B in activating Mutator, we performed Chromatin Immunoprecipitation (ChIP) analysis using polyclonal antibodies specific for MURA to assess the in vivo binding capacity of the transposase to its target site in the Mu TIRs. We found that UV-B irradiation induces the binding of MURA to MuDR TIR in both active and silencing plant leaves. In addition, using plants containing a modified transposon RescueMu, we found that at least in Mutator active plants, novel excision events occur after 8h UV-B treatments. (authors)

  11. Hybridization-Induced Aggregation Technology for Practical Clinical Testing: KRAS Mutation Detection in Lung and Colorectal Tumors.

    Science.gov (United States)

    Sloane, Hillary S; Landers, James P; Kelly, Kimberly A

    2016-07-01

    KRAS mutations have emerged as powerful predictors of response to targeted therapies in the treatment of lung and colorectal cancers; thus, prospective KRAS genotyping is essential for appropriate treatment stratification. Conventional mutation testing technologies are not ideal for routine clinical screening, as they often involve complex, time-consuming processes and/or costly instrumentation. In response, we recently introduced a unique analytical strategy for revealing KRAS mutations, based on the allele-specific hybridization-induced aggregation (HIA) of oligonucleotide probe-conjugated microbeads. Using simple, inexpensive instrumentation, this approach allows for the detection of any common KRAS mutation in platform may involve the detection of mutations in other key oncogenic pathways. PMID:27289420

  12. Morphological mutations induced by gamma rays, ethylene imine and N-nitroso-N-ethyl urea in lentil (Lens culinaris medik.)

    International Nuclear Information System (INIS)

    Dry and healthy seeds of a large seeded lentil cv, 'Precoz Selection', were treated with three doses each of gamma rays, ethylene imine (EI) and N-nitroso-N-ethyl urea (NEU). Based on the frequency of morphological mutations, the mutagens were arranged in the order: NEU > EI >. Gamma rays and dose-dependent relationship was observed in the case of gamma rays (5 kR 1 damage groups induced morphological mutations in the order: HH > HL > LH > LL. The morphological mutations included changes for growth habit, foliage, plant height and maturity and flowering behaviour. A mild relative mutagenic specificity and differences in mutability of genes for different traits were observed, In general the spectrum of morphological mutations was not influenced by the groups of M1 damage, except that some mutation types occurred more frequently, than others in certain groups. (author)

  13. Effects of some natural extracts on tradescantia somatic cell pink mutation frequencies induced by gamma-ray

    International Nuclear Information System (INIS)

    This study deals with the effect of some natural extracts on the pink mutations induced by radiation in Tradescantia 4430 stamen hair cells. Inflorescence cuttings, with or without pretreatments of natural extracts for 3 hours, were exposed to 1 Gy of gamma ray. Comparisons were made on the basis of pooled data during the peak interval between the mean pink mutation frequencies of the two experimental groups. Pretreatments of FB or FB-I resulted in two-fold increases of the pink mutation frequencies, compared to those of control group. Synergism between certain fractions and radiation was a possible cause of increased DNA damage. On the other hand, the extract PG in proper concentrations significantly reduced the pink mutation frequencies (p<0.05). The result meant that PG had a protective effect on radiation-induced cell damage. Tradescantia proved to be an excellent biological model system for assessing the radiomodification effects of natural materials

  14. Achievements and prospects of sunflower genetics, breeding and induced mutation utilization

    International Nuclear Information System (INIS)

    The importance of sunflower, some flower characteristics, genetics and breeding advances, considerations on model characters and induced mutation breeding are presented and discussed. The sunflower open-pollinated varieties and single and three-way hybrids that are currently being cultivated represent the valuable results of the breeding of improved cultivars. To keep up this activity, breeders have concentrated most of their efforts on using variability in cultivated sunflower and its related wild species, and not on increasing the range of existing variability. Limited experiments with high-energy radiation, ultraviolet rays and chemicals indicated that additional, very useful variability could be induced. Mutagenic agents should be used for breeding a certain type of cultivar with a vegetative cycle and morphological traits adjusted to certain growing conditions, and possessing a satisfactory capacity to utilize all environmental factors, high seed and oil yields and a high resistance to local diseases, insects and predators. (author)

  15. Induced mutations for disease resistance to leaf spot fungi in soybean

    International Nuclear Information System (INIS)

    Three soybean cultivars, Calland, Columbus and Williams, were used to induce mutant(s) resistant to leaf spot fungi through the use of gamma irradiation. Twenty thousand dry seeds of the three cultivars were irradiated with 20 krad of gamma rays and sown to obtain the M1 plants. Irradiation reduced the number of seedlings that emerged and surviving plants. In addition, apparently normal and abnormal phenotypes were observed. The M2 plants were subjected to an artificial epiphytotic with two leaf spot fungi, i.e. Drechslera australiensis and Alternaria alternata. Reactions of the M2 generation suggested that the induced resistances to both fungi were of a polygenic nature. In the M3 generation, 30 and 25 mutants originated from 16 and 18 families of the three cultivars were found to be breeding true for resistance to D. australiensis and A. alternata, respectively. Other mutations were also recorded. (author). 9 refs, 9 tabs

  16. Tn5-induced pBS286 plasmid mutations blocking early stages of napthalene oxidation

    International Nuclear Information System (INIS)

    The authors present data on the further analysis of the structural and functional organization of the nah region of plasmid pBS286 controlling the constitutive oxidation of naphthalene by Pseudomonas putida cells. They have studied Tn5-induced mutations blocking early stages of naphthalene oxidation. They present and discuss data providing evidence that, in contrast to plasmid NAH7, the mechanism of regulation of the nahl operon of plasmid NPL-1, the parent plasmid of plasmid pBS286, with inducible synthesis of naphthalene dioxygenase can include elements of a negative control with participation of the regulatory locus R, located proximal to the structural nah genes and closely linked to or overlapped by the inverted control DNA segment (4.2 kb). They also present data on the possibility of regulation of the activity of the catechol-splitting meta-pathway genes with the participation of products of early stages of naphthalene oxidation

  17. Induced mutagenesis as a source of new mutations in maize (Zea mays L.)

    International Nuclear Information System (INIS)

    Full text: Seed samples of 9 inbreds were treated with MNU. Mutant individuals were visually selected in M2 and M3. Mutability was determined in 100 loci by crossing induced mutants with some well-known natural mutants obtained from the U.S. Association of Corn Geneticists. Only viable mutants characterised with distinct stable traits connected with kernel texture and mature plant were taken for tests. Mapping of the expected new mutants was realised through A-B translocations and marker lines. Evaluation of the mutant alleles' effect on yield and quality of biomass in inbreds and heterotic hybrids was done by the standard methods. The results show the ability of artificial mutagens to induce mutations in previously known loci. The genotype of the inbreds greatly affects the probability of mutation occurrence in a new locus. Due to the mutagen effect, independently inherited complexes of traits or naturally polygenic traits may become monogenic. This results in simplified inheritance, in an increase in heritability and thus in high effectiveness of selection. (author)

  18. Mutation breeding in sweet potato with fast neutrons by inducing hypocotyl adventitious buds

    International Nuclear Information System (INIS)

    Hybrid sweet potato seeds were irradiated by fast neutrons. After the irradiation, adventitious buds were induced from the epidermal cells of the hypocotyls of the seedlings. The adventitious buds appeared from the hypocotyls 2 - 3 cm below the cotyledonary node. Detailed observations of cell division and tissue dissection showed that some adventitious buds emerged in 20 - 45 days after seedling emergence. Most of them originated from a single cell. These adventitious bud clones showed a wide mutation spectrum at high frequency, mostly non-chimeric. The mutant characters included the color of leaf, vine, vein, root-tuber skin and the leaf shape, yield, root-tuber dry matter rates, root-tuber numbers, sprouting, early tuber formation, resistance to black rot, root rot, nematodes etc. The results were confirmed in the field; the observed mutant characters were stable and non-chimeric. Such a method of inducing mutations is advantageous for the improvement of economic characters. Actually, there were examples of increasing the dry matter content of the tubers by 1.0 - 5.5%, the yield of tubers increased by 3.6 - 53.8%, and tubers per plant increased by 0.6 - 4.2%. The resistances to black rot, root rot, nematodes etc. were also improved. Three multiple resistance varieties Yanshu 568, Yanshu 571-1, 84-C-2 and two good quality varieties Yanshu 759 and 781 have been selected. (author). 9 refs, 3 tabs

  19. Somaclonal Variation Is Induced De Novo via the Tissue Culture Process: A Study Quantifying Mutated Cells in Saintpaulia

    OpenAIRE

    Mitsuru Sato; Munetaka Hosokawa; Motoaki Doi

    2011-01-01

    BACKGROUND: The origin of somaclonal variation has not been questioned previously, i.e., "pre-existing mutations" in explants and "newly induced mutations" arising from the tissue culture process have not been distinguished. This is primarily because there has been no reliable molecular method for estimating or quantifying variation. METHODOLOGY/PRINCIPAL FINDINGS: We adopted a petal-variegated cultivar of Saintpaulia 'Thamires' (Saintpaulia sp.) as the model plant. Based on the difference be...

  20. A comparison of mutations induced by accelerated iron particles versus those induced by low earth orbit space radiation in the FEM-3 gene of Caenorhabditis elegans

    Science.gov (United States)

    Hartman, P. S.; Hlavacek, A.; Wilde, H.; Lewicki, D.; Schubert, W.; Kern, R. G.; Kazarians, G. A.; Benton, E. V.; Benton, E. R.; Nelson, G. A.

    2001-01-01

    The fem-3 gene of Caenorhabditis elegans was employed to determine the mutation frequency as well as the nature of mutations induced by low earth orbit space radiation ambient to Space Shuttle flight STS-76. Recovered mutations were compared to those induced by accelerated iron ions generated by the AGS synchrotron accelerator at Brookhaven National Laboratory. For logistical reasons, dauer larvae were prepared at TCU, transported to either Kennedy Space Center or Brookhaven National Laboratory, flown in space or irradiated, returned to TCU and screened for mutants. A total of 25 fem-3 mutants were recovered after the shuttle flight and yielded a mutation frequency of 2.1x10(-5), roughly 3.3-fold higher than the spontaneous rate of 6.3x10(-6). Four of the mutations were homozygous inviable, suggesting that they were large deletions encompassing fem-3 as well as neighboring, essential genes. Southern blot analyses revealed that one of the 25 contained a polymorphism in fem-3, further evidence that space radiation can induce deletions. While no polymorphisms were detected among the iron ion-induced mutations, three of the 15 mutants were homozygous inviable, which is in keeping with previous observations that high LET iron particles generate deficiencies. These data provide evidence, albeit indirect, that an important mutagenic component of ambient space radiation is high LET charged particles such as iron ions.

  1. Induced mutations in bread wheat variety VL404 and their characterization

    International Nuclear Information System (INIS)

    Mutations were induced in a leaf rust resistant Indian wheat cultivar VL404 using 0.4% Ethymethane sulphonate treatment for 16 hrs. Highest frequency of 1.94 chlorophyll mutations/100 M1 spikes was obtained. Frequency of different viable mutations varied from 1.20 mutations/100 M1 spikes to 2.61 mutations/100 M1 spikes. Of the 161 viable mutants isolated, seventy six mutants showed stable expression in M3 and M4 generations. These were characterized for important characteristics. Three mutants having height more than and 58 mutants having height less than VL404 were observed. The spike length of mutants varied from 3.5 to 12 cm, compared to 8.5 cm of VL404. VL404 had 21 spikelets on an average in a spike, whereas 9 mutants had 23 spikelets/spike. Large variation (10 to 69 grains) in the number of grains per ear was observed in the mutants as compared to VL404 (65 grains). Mutants having up to 35 tillers were obtained as compared to 19 tillers of VL404 on an average. Cultivar VL404 has oblong grains whereas four mutants have round grains. Four mutants each having compact and sub-compact ears and twelve mutants having lax ears were recovered. VL404 has speltoid ears. Of the 76 mutants characterized, 18 showed light red to red and 3 mutants showed yellow grain colour as compared to the amber seeds of cultivar VL404. Mutants growing slower than VL404 were also recovered. A mutant bearing measled leaves with similarity to disease lesion mimics was recorded. Three mutants with waxy leaves having cup-shaped leaf tip were obtained. Twenty three of the 76 characterized mutants produced susceptible infection types on adult plants of VL404 indicating break down of resistance of VL404 to leaf rust. Origin of sequence variation in chromosomes 2A and 4B was observed when mutants were tested using 56 SSR markers specific to these chromosmes. (author)

  2. A two-mutation model of radiation-induced acute myeloid leukemia using historical mouse data.

    Science.gov (United States)

    Dekkers, Fieke; Bijwaard, Harmen; Bouffler, Simon; Ellender, Michele; Huiskamp, René; Kowalczuk, Christine; Meijne, Emmy; Sutmuller, Marjolein

    2011-03-01

    From studies of the atomic bomb survivors, it is well known that ionizing radiation causes several forms of leukemia. However, since the specific mechanism behind this process remains largely unknown, it is difficult to extrapolate carcinogenic effects at acute high-dose exposures to risk estimates for the chronic low-dose exposures that are important for radiation protection purposes. Recently, it has become clear that the induction of acute myeloid leukemia (AML) in CBA/H mice takes place through two key steps, both involving the Sfpi1 gene. A similar mechanism may play a role in human radiation-induced AML. In the present paper, a two-mutation carcinogenesis model is applied to model AML in several data sets of X-ray- and neutron-exposed CBA/H mice. The models obtained provide good fits to the data. A comparison between the predictions for neutron-induced and X-ray-induced AML yields an RBE for neutrons of approximately 3. The model used is considered to be a first step toward a model for human radiation-induced AML, which could be used to estimate risks of exposure to low doses. PMID:20842369

  3. Biphenyl compounds are hydroxyl radical scavengers: their effective inhibition for UV-induced mutation in Salmonella typhimurium TA102.

    Science.gov (United States)

    Fujita, S; Taira, J

    1994-09-01

    In our previous study, we found several hydroxylated biphenyl compounds have a great scavenging effect for hydroxyl radicals (.OH). In this study, to elucidate the relationship between generation of the .OH and photo-mutagenesis, six biphenyl compounds such as dehydrodieugenol, dehydrodivanillyl alcohol, dehydrodidihydroeugenol, dehydrodicreosol, magnolol and honokiol, respectively, were examined for their ability to inhibit UV-induced mutation in Salmonella typhimurium TA102. The relative mutagenic activities (RMA, %) indicated the mutation frequency of treated cells divided by the mutation frequency of control cells times 100%. The RMA (%) are as follows: 28 +/- 1, 31 +/- 1, 33 +/- 1, 41 +/- 2, 62 +/- 1, and 62 +/- 4 at concentrations of 5 micrograms per plate for dehydrodieugenol, dehydrodivanillyl alcohol, dehydrodidihydroeugenol, dehydrodicreosol, magnolol, and honokiol, respectively. These values indicate that low concentrations of these biphenyl compounds effectively suppress UV-induced mutagenesis. Also, these compounds acted as effective antimutagens in a dose-dependent manner (0.00005-5 micrograms per plate). These compounds are effective .OH scavengers. Consequently, the results obtained above suggest that these compounds could inhibit against UV-induced mutations by scavenging of .OH generated by UV irradiation. The results also suggest that .OH are associated with UV-induced mutation in Salmonella typhimurium TA102. PMID:7982632

  4. LEOPARD syndrome-associated SHP2 mutation confers leanness and protection from diet-induced obesity.

    Science.gov (United States)

    Tajan, Mylène; Batut, Aurélie; Cadoudal, Thomas; Deleruyelle, Simon; Le Gonidec, Sophie; Saint Laurent, Céline; Vomscheid, Maëlle; Wanecq, Estelle; Tréguer, Karine; De Rocca Serra-Nédélec, Audrey; Vinel, Claire; Marques, Marie-Adeline; Pozzo, Joffrey; Kunduzova, Oksana; Salles, Jean-Pierre; Tauber, Maithé; Raynal, Patrick; Cavé, Hélène; Edouard, Thomas; Valet, Philippe; Yart, Armelle

    2014-10-21

    LEOPARD syndrome (multiple Lentigines, Electrocardiographic conduction abnormalities, Ocular hypertelorism, Pulmonary stenosis, Abnormal genitalia, Retardation of growth, sensorineural Deafness; LS), also called Noonan syndrome with multiple lentigines (NSML), is a rare autosomal dominant disorder associating various developmental defects, notably cardiopathies, dysmorphism, and short stature. It is mainly caused by mutations of the PTPN11 gene that catalytically inactivate the tyrosine phosphatase SHP2 (Src-homology 2 domain-containing phosphatase 2). Besides its pleiotropic roles during development, SHP2 plays key functions in energetic metabolism regulation. However, the metabolic outcomes of LS mutations have never been examined. Therefore, we performed an extensive metabolic exploration of an original LS mouse model, expressing the T468M mutation of SHP2, frequently borne by LS patients. Our results reveal that, besides expected symptoms, LS animals display a strong reduction of adiposity and resistance to diet-induced obesity, associated with overall better metabolic profile. We provide evidence that LS mutant expression impairs adipogenesis, triggers energy expenditure, and enhances insulin signaling, three features that can contribute to the lean phenotype of LS mice. Interestingly, chronic treatment of LS mice with low doses of MEK inhibitor, but not rapamycin, resulted in weight and adiposity gains. Importantly, preliminary data in a French cohort of LS patients suggests that most of them have lower-than-average body mass index, associated, for tested patients, with reduced adiposity. Altogether, these findings unravel previously unidentified characteristics for LS, which could represent a metabolic benefit for patients, but may also participate to the development or worsening of some traits of the disease. Beyond LS, they also highlight a protective role of SHP2 global LS-mimicking modulation toward the development of obesity and associated disorders

  5. Induced mutation in narrow-leafed lupin improvement: An example of herbicide tolerance

    International Nuclear Information System (INIS)

    Spontaneous mutation has been discovered and utilized in domestication of narrow-leafed lupin (Lupinus angustifolius L.). As the result of the domestication, lupin has become a dominant grain legume crop in Western Australia. Facing the new challenge of developing herbicide tolerance cultivars, chemical mutagenesis has been used to create new tolerance to herbicide. This paper reports the characterization of two lupin mutants (Tanjil-AZ-33 and Tanjil-AZ-55) that are highly tolerant to metribuzin herbicide. A dose response study over 8 doses revealed that Tanjil-AZ-33 was 6 times more tolerant to metribuzin than the original parental cultivar Tanjil by measure of LD50. This mutant Tanjil-AZ-33 is the most tolerant germplasm in narrow-leafed lupin. Both mutants also maintain the high resistance to the disease anthracnose as cv Tanjil. Seed yield based on small field plots (3.6 m2) under irrigation was 4.2 t/ha for Tanjil-AZ-33 and 1.9 t/ha for Tanjil when the seedlings subject to metribuzin at 300 g/ha at 6 leaf stage. Seed yields of both Tanjil-AZ-33 and Tanjil-AZ-55 were similar to Tanjil in absence of the herbicide. These facts indicate that the mutation process has created tolerance to metribuzin in Tanjil, but has not altered Tanjil's yield capacity and anthracnose resistance. The mutant Tanjil-AZ-33 has been used as a parent in the lupin breeding program and we expect future lupin cultivars will have increased metribuzin tolerance. Induced mutation proves to be an effective tool in lupin improvement. (author)

  6. Induced Mutation in Narrow-Leafed Lupin Improvement: An Example of Herbicide Tolerance

    International Nuclear Information System (INIS)

    Spontaneous mutation has been discovered and utilized in domestication of narrow-leafed lupin (Lupinus angustifolius L.). As a result of domestication, lupin has become a dominant grain legume crop in Western Australia. Facing the new challenge of developing herbicide tolerant cultivars, chemical mutagenesis has been used to create new tolerance to herbicide. This paper reports the characterization of two lupin mutants (Tanjil-AZ-33 and Tanjil-AZ-55) that are highly tolerant to metribuzin herbicide. A dose response study of over eight doses revealed that Tanjil-AZ-33 was six times more tolerant to metribuzin than the original parental cultivar Tanjil, as measured by LD50. This mutant Tanjil-AZ-33 is the most tolerant germplasm in narrow-leafed lupin. Both mutants also maintain the high resistance to the disease anthracnose as in cv Tanjil. Seed yield based on small field plots (3.6 m2) under irrigation was 4.2 t/ha for Tanjil-AZ-33 and 1.9 t/ha for Tanjil when the seedlings were subjected to 300 g/ha metribuzin at the six-leaf stage. Seed yields of both Tanjil-AZ-33 and Tanjil-AZ-55 were similar to Tanjil in absence of the herbicide. These facts indicate that the mutation process has created tolerance to metribuzin in Tanjil, without altering its yield capacity and anthracnose resistance. The mutant Tanjil-AZ-33 has been used as a parent in the lupin breeding programme and we expect future lupin cultivars to have increased metribuzin tolerance. Induced mutation proved to be an effective tool in lupin improvement. (author)

  7. Induced mutations to develop sources of resistance to rice blast, Pyricularia grisea Sacc

    International Nuclear Information System (INIS)

    Rice blast caused by Pyricularia grisea is the most important disease limiting yields worldwide. The pathogen has many virulent forms or pathotypes, hence durable blast resistance is lacking. Studies on strategy to develop durable blast resistance based on defining the genetic structure of the population, using DNA-fingerprinting, and virulence diversity are described. This strategy is leading to the identification of resistance genes/sources against all isolates within a genetic family of the pathogen. Combinations of genes showing complementary resistance to different genetic families of the fungus exclude any compatible interaction with a blast isolate. Identification of complementary resistance genes is based on detecting those virulence factors whose combinations in individual isolates within the pathogen population have a frequency near zero. Identifying and combining resistance genes to which combinations of corresponding virulence genes are absent in the pathogen population should confer more durable resistance than that previously obtained. The use of induced mutations in the development of resistance was limited, since in most cases single gene changes were responsible for the induced resistance against all the pathogen population. The main objective here is to develop many mutants, each with a gene resistant to just one or a few families of the blast pathogen; and crossing them can accumulate the different resistance genes. A total of 201 Latin American commercial cultivars, including Cuban, Brazilian and Venezuelan were analyzed with different genetic families of the blast pathogen to identify potential sources of resistance to blast and identify complementary resistance sources. Characterization of the resistance of 37 mutants of the Colombian rice cultivar Oryzica 1 was conducted in collaboration with the INEA in Colombia. Results suggested that mutations for resistance to genetic families to which Oryzica 1 is susceptible were induced, although one

  8. Radiation-induced point mutations, deletions and micronuclei in lacI transgenic mice

    International Nuclear Information System (INIS)

    The development of transgenic mutagenesis systems has now made it possible to study the effects of ionizing radiation at both the molecular and chromosomal levels in the same animal. In this report we present preliminary data on the response of Big BlueTM lacI transgenic mice to ionizing radiation as measured by lacI mutations and micronuclei. C57Bl/6 transgenic mice were irradiated with 137Cs γ-rays at doses ranging from 0.1 to 14 Gy, and expression times ranging from 2 to 14 days. Dose-related increases in the mutant frequency were observed after irradiations with longer expression times. Mutant plaques were analyzed by restriction enzyme digestion to detect large structural changes in the target sequence. Of 34 γ-ray- induced mutations analyzed, 4 were large-scale rearrangements. Three of these rearrangements were deletions within the lacI gene characterized by the presence of short regions of homology at the breakpoint junctions. The fourth rearrangement was a deletion that extended from within the αlacZ gene into downstream sequences and that had 43 bp of homology at the junction. These data indicate that the Big BlueTM lacI transgenic mouse system is sensitive to the types of mutations induced by ionizing radiation. To determine whether the presence of the transgene affects micronucleus induction we compared the response of nontransgenic to hemizygous transgenic B6C3F1 mice and the response of nontransgenic to hemizygous and homozygous transgenic C57Bl/6 mice. The presence or absence of the lacI transgene had no effect on spontaneous micronucleus frequencies for either strain. However, radiation-induced micronucleus frequencies were significantly higher in hemizygous lacI B6C3F1 mice than in nontransgenic litter mates; the converse was true in C57Bl/6 mice. These data suggest that the lacI transgene does not cause chromosome instability as measured by spontaneous micronucleus levels. However, the response of these transgenic mice to a variety of

  9. Comparison of somatic mutation frequencies at HGPRT locus induced by radiation and chemical pollutant from energy system

    International Nuclear Information System (INIS)

    The somatic induction frequencies of mutation at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus induced by 60Co γ-rays and Benzo-a-pyrene (B(a)P), which are representative of hazardous emission and pollutant from nuclear energy cycle and fossil-fuelled energy cycle respectively, were detected by using forward mutation assay and cloning technique in both V79 Chinese hamster cells and human peripheral blood T-lymphocytes. Resistant mutants were selected with 6-thioguanine (6-TG). Dose-response curves and mathematical expressions were obtained for mutation frequencies and survival following γ-ray and B(a)P(+S9) treatments. The dose ranges for the two mutagens were compared when they induced the same mutation frequencies. In V79/HGPRT assay system, when the mutation frequencies were 5∼35 mutants/106 cells the response of γ-rays in the dose range from 0.93∼4.96 Gy at dose rate of 1.16 Gy/min is nearly equivalent to that in the B(a)P dose range from 0.52∼4.27 μg/ml. By using cloning technique in T-lymphocytes, when the mutation frequencies were 1∼14 mutants/105 cells the response of γ-rays in the dose range from 0.05∼4.77 Gy at dose rate of 1.03 Gy/min is nearly equivalent to that in the B(a)P dose range from 0.15∼7.36 μg/ml. When the survival fraction is 37%, the mutation frequency induced by B(a)P is higher than that induced by 60Co γ-rays

  10. Research work and demonstration of crop space-induced mutation breeding in Guangdong academy of agricultural science

    International Nuclear Information System (INIS)

    138 entries of crop seeds, seedlings and sources of microbe, including conventional rice varieties, hybrid rice, vegetable, flower, mulberry, tea, and silkworm, were sent for space mutation. Muti-suject combining research had been conducted on the innovation of new gemplasm, breeding for new varieties and elucidating the physiological and molecular mechanism of space induced mutation. Based on the displaying platform fro crop breeding in national Agri- Tech displaying land in Guangzhou, Guangdong. Space Agri-Tech Displaying Land was being constructed large scale displaying land for space induced breeding in Guangdong will be developed in collaboration with the Provincial production management agencies. (authors)

  11. A novel radiation-induced p53 mutation is not implicated in radiation resistance via a dominant-negative effect.

    Directory of Open Access Journals (Sweden)

    Yunguang Sun

    Full Text Available Understanding the mutations that confer radiation resistance is crucial to developing mechanisms to subvert this resistance. Here we describe the creation of a radiation resistant cell line and characterization of a novel p53 mutation. Treatment with 20 Gy radiation was used to induce mutations in the H460 lung cancer cell line; radiation resistance was confirmed by clonogenic assay. Limited sequencing was performed on the resistant cells created and compared to the parent cell line, leading to the identification of a novel mutation (del at the end of the DNA binding domain of p53. Levels of p53, phospho-p53, p21, total caspase 3 and cleaved caspase 3 in radiation resistant cells and the radiation susceptible (parent line were compared, all of which were found to be similar. These patterns held true after analysis of p53 overexpression in H460 cells; however, H1299 cells transfected with mutant p53 did not express p21, whereas those given WT p53 produced a significant amount, as expected. A luciferase assay demonstrated the inability of mutant p53 to bind its consensus elements. An MTS assay using H460 and H1299 cells transfected with WT or mutant p53 showed that the novel mutation did not improve cell survival. In summary, functional characterization of a radiation-induced p53 mutation in the H460 lung cancer cell line does not implicate it in the development of radiation resistance.

  12. Rice improvement through radiation-induced mutation for cultivation in South Vietnam

    International Nuclear Information System (INIS)

    For past years, rice varieties cultivated in South Vietnam originated from domestic hybridisation or from IRRI. Rice mutation breeding has been initiated for recent years. To meet the requirement of rice production diversification in different agro-ecological areas and rice genetic resources, from 1993 Institute of Agricultural Science of South Vietnam has carried out rice improvement by induced mutation of radiation. The mutagen was gamma rays of 60Co. The goal is to create inherited variations, which cannot be obtained from other breeding methods, specially important characters of rice varieties (high tolerance to acid sulfate soil, lodging resistance combined with early maturity), which were difficult to gain by hybridisation. With 60Co gamma rays, doses of 10-20 krad, dose rate of 280 krad/h, dry and germinated seeds of introduced and local rice varieties (IR 64, IR 9729, IR 50404, IR 59606, Jasmine 85, Nang Huong, Tam Xoan) were irradiated. The irradiated seeds were immediately sown within 24 and 94 hrs for wet seeds and dry seeds after treatment, respectively. Population of 10,000-15,000 plants were established and evaluated by IRRI evaluation standard from M2-M7 generations. 365 lines, varieties were selected with better behaviours than original varieties as lodging resistance, earliness, potential yield, leaf characters, tolerant ability to adverse conditions etc. Some good varieties (VND95-19, VND95-20) have been approved as leading national varieties and released for large-scale production in South Vietnam. (author)

  13. Improvement of rice through somaculture and induced mutations in Sao Paulo State

    International Nuclear Information System (INIS)

    Rice (Oryza sativa L.) is one of the most important crops in Sao Paulo State, Brazil, from both the production and mainly the consumption standpoint. It is cultivated predominantly under upland conditions in areas that have high temperature and humidity, excellent environment for rapid spreading of the blast disease (Pyricularia grisea). The objective of this research was to induce mutations in connection with somaculture, for resistance to blast and a high yield potential, retaining the other qualities of IAC 201, a commercial upland variety. Seeds were irradiated with 60Co gamma rays at 300, 350 and 400 Gy, and boots and seeds from M1 plants in the 300 Gy treatments were harvested for mutation in vitro and in vivo techniques. Selection was not done in M2 generation; panicles were harvested and the offsprings were evaluated in the M3 generation for blast reaction. From 10340 panicles screened, 267 lines were selected with a possible blast tolerance. In the M4 generation these populations were again evaluated for blast reaction and for agronomic traits. Fifty-three possible mutant lines with tolerance to blast were selected, with more than 15% increments in yield potential. From these lines it is expected that at least one will be released in the near future as a new, resistant upland rice cultivar for Sao Paulo State, Brazil. (author)

  14. Study on mutation induced effect of gamma ray and DES on black bean phaseolus vulgaris

    International Nuclear Information System (INIS)

    The study on mutation induced effect of gamma ray and DES on black bean Phaseolus vulgaris was carried out at Radiobiology Department, Nuclear Research Institute of Dalat. Dry seeds of variety No.1847 - Bonita - Cuba in set of 13 black bean varieties were irradiated with gamma ray from 60Co source at dose range from 150 Gy to 350 Gy and treated with DES at concentration from 0.1% to 0.3% in 2 hours for experiments in laboratory. The doses of 200, 250, 300 Gy and concentration of 0.2% DES in 2 hours were selected to treat dry seeds for experiments on the field. In populations of M1 generation, the height, number of branches and fruits per plant, number of seeds per fruit were decreased with increasing of irradiation doses. In populations of M2 generation, individual variants in leaf shape, chlorophyll, short stem, dwarf, early maturity, flowering in very short time were obtained and selected in all treatment cases. Mutation frequency at dose of 300 Gy was higher than that in other treatment cases, but ratio of sterility is also largest. The mutant lines of early maturity and short stem with flowering in very short time are promised materials for further studies. (author)

  15. A triple-helix forming oligonucleotide targeting genomic DNA fails to induce mutation.

    Science.gov (United States)

    Reshat, Reshat; Priestley, Catherine C; Gooderham, Nigel J

    2012-11-01

    Purine tracts in duplex DNA can bind oligonucleotide strands in a sequence specific manner to form triple-helix structures. Triple-helix forming oligonucleotides (TFOs) targeting supFG1 constructs have previously been shown to be mutagenic raising safety concerns for oligonucleotide-based pharmaceuticals. We have engineered a TFO, TFO27, to target the genomic Hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus to define the mutagenic potential of such structures at genomic DNA. We report that TFO27 was resistant to nuclease degradation and readily binds to its target motif in a cell free system. Contrary to previous studies using the supFG1 reporter construct, TFO27 failed to induce mutation within the genomic HPRT locus. We suggest that it is possible that previous reports of triplex-mediated mutation using the supFG1 reporter construct could be confounded by DNA quadruplex formation. Although the present study indicates that a TFO targeting a genomic locus lacks mutagenic activity, it is unclear if this finding can be generalised to all TFOs and their targets. For the present, we suggest that it is prudent to avoid large purine stretches in oligonucleotide pharmaceutical design to minimise concern regarding off-target genotoxicity. PMID:22914677

  16. Rice improvement through radiation-induced mutation for cultivation in South Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Do Khac Thinh; Hung Phi Oanh; Nguyen Thi Cuc; Nguyen Ngoc Quynh [Institute of Agricultural Science of South Vietnam, Ho Chi Minh (Viet Nam)

    2001-03-01

    For past years, rice varieties cultivated in South Vietnam originated from domestic hybridisation or from IRRI. Rice mutation breeding has been initiated for recent years. To meet the requirement of rice production diversification in different agro-ecological areas and rice genetic resources, from 1993 Institute of Agricultural Science of South Vietnam has carried out rice improvement by induced mutation of radiation. The mutagen was gamma rays of {sup 60}Co. The goal is to create inherited variations, which cannot be obtained from other breeding methods, specially important characters of rice varieties (high tolerance to acid sulfate soil, lodging resistance combined with early maturity), which were difficult to gain by hybridisation. With {sup 60}Co gamma rays, doses of 10-20 krad, dose rate of 280 krad/h, dry and germinated seeds of introduced and local rice varieties (IR 64, IR 9729, IR 50404, IR 59606, Jasmine 85, Nang Huong, Tam Xoan) were irradiated. The irradiated seeds were immediately sown within 24 and 94 hrs for wet seeds and dry seeds after treatment, respectively. Population of 10,000-15,000 plants were established and evaluated by IRRI evaluation standard from M2-M7 generations. 365 lines, varieties were selected with better behaviours than original varieties as lodging resistance, earliness, potential yield, leaf characters, tolerant ability to adverse conditions etc. Some good varieties (VND95-19, VND95-20) have been approved as leading national varieties and released for large-scale production in South Vietnam. (author)

  17. Physiological, biochemical and molecular characterization of an induced mutation conferring imidazolinone resistance in wheat.

    Science.gov (United States)

    Jimenez, Francisco; Rojano-Delgado, Antonia M; Fernández, Pablo Tomas; Rodríguez-Suárez, Cristina; Atienza, Sergio G; De Prado, Rafael

    2016-09-01

    The Clearfield(®) wheat cultivars possessing imidazolinone (IMI)-resistant traits provide an efficient option for controlling weeds. The imazamox-resistant cultivar Pantera (Clearfield(®) ) was compared with a susceptible cultivar (Gazul). Target and non-target mechanisms of resistance were studied to characterize the resistance of Pantera and to identify the importance of each mechanism involved in this resistance. Pantera is resistant to imazamox as was determined in previous experiments. The molecular study confirmed that it carries a mutation Ser-Asn627 conferring resistance to imazamox in two out of three acetolactate synthase (ALS) genes (imi1 and imi2), located in wheat on chromosomes 6B and 6D, respectively. However, the last gene (imi3) located on chromosome 6A does not carry any mutation conferring resistance. As a result, photosynthetic activity and chlorophyll content were reduced after imazamox treatment. Detoxification was higher in the resistant biotype as shown by metabolomic study while imazamox translocation was higher in the susceptible cultivar. Interestingly, imazamox metabolism was higher at higher doses of herbicide, which suggests that the detoxification process is an inducible mechanism in which the upregulation of key gene coding for detoxification enzymes could play an important role. Thus, the identification of cultivars with a higher detoxification potential would allow the development of more resistant varieties. PMID:26991509

  18. Chloromutations and seedling morphology mutations induced by separate and simultaneous applications of gamma rays and NMU in lentil

    International Nuclear Information System (INIS)

    Chloromutations and seedling morphology mutations were induced in lentil var T.36 by separate and synergistic action of gamma rays and nitrosomethyl urea (NMU). Seed germination % in the M2 population (subjected to various treatments) was less than that of the control. Frequencies and spectra of chlorophyll and seedling morphology mutations were recorded based on percent of segregating families as well as mutants/thousand of M2 seedlings. The frequency of chlorophyll mutations in terms of segregating families was higher in the NMU treatment, while on the basis of per thousand M2 seedlings, the frequency was much higher in the gamma ray treatments. The frequency of seedling morphology mutations in the NMU treatment, however, was higher than in any of the gamma ray treatments, based on both criteria

  19. Study on HPRT gene locus mutation of human peripheral blood lymphocytes induced by γ ray using clone method

    International Nuclear Information System (INIS)

    To study the HPRT Gene Locus Mutation of Human Peripheral Blood Lymphocytes Induced by γ Ray Using Clone Method. Method: Lymphocytes were separated from human peripheral blood using Fycoll-hypaque density centrifugation and planted in the wells of microtiter plates with a flat bottom to clone lymphocytes and screen the cells with HPRT gene mutation. Results: In some range of radiation dose, the clone efficiency of Human Peripheral Blood Lymphocytes has negative correlation to radiation dose, and the model is y = 49.8100 - 4.4655 D, r2 = 0.9662, r2 = 0.9951; while the HPRT mutation frequency has positive correlation to radiation dose, and the model is y = 0.0958 + 1.5501 D, r 2 = 0.9878. Conclusion: HPRT gene is sensitive to radiation, and in some range of radiation dose, the HPRT mutation frequency has positive correlation to radiation dose

  20. The use of induced mutation combined with crossing in high quality rice breeding

    International Nuclear Information System (INIS)

    The high quality rice varieties: Tam thom mutant rice Var., DT17 rice Var, DT21 glutinous rice Var were formed by induced mutation combined with crossing. Tam thom mutant rice Var. lost photosensitivity, could be planted 2 crops/year. DT17 rice Var with high yielding capacity, suitable for growth on lowland in summer crop, is replacing step-by-step Moctuyen rice Var. in North Vietnam. DT21 glutinous rice Var. could be planted 2 crops/year and had short growth duration, average yield was 4.0-4.5 tons/ha. These three ones had good quality, soft and scent cooked rice, suitable for customers and export requirements. Tam thom mutant rice Var. DT17 rice Var., DT21 and glutinous rice Var. were adopted for regional production by Ministry of Agriculture and Rural Development and allowed to be in trial production. (author)

  1. Cereal crop resistance to insects in the United States. An example of induced mutation

    International Nuclear Information System (INIS)

    In the United States, entomologists and plant scientists are cooperating in the production of varieties of cereal crops (corn, wheat, and sorghum) that have commercially effective resistance to key pests. Active research is in progress on plant resistance to the European corn borer, southwestern corn borer, corn earworm, corn rootworms, greenbug, sorghum midge, Hessian fly, and cereal leaf beetle. Plant resistance has had an important role in reducing the chinch bug and the wheat stem sawfly to minor pests. There are deficiencies of programs in the U.S. For example, collections of cereal crop germplasm are large, and most have not been adequately evaluated. Induced mutation research could be highly useful for specific objectives. The transfer of greenbug resistance from rye to wheat is an example. (author)

  2. Production of bacterial leaf blight resistant mulberry through tissue culture and induced mutation

    International Nuclear Information System (INIS)

    Mon Noi multiple shoots obtained from axillary buds in vitro cultures were induced mutation by irradiating with gamma rays at the optimum dose (LD 50) of 40 Gy. In vitro inoculation technique for bacterial blight disease of mulberry caused by Pseudomonas syringae p v. mori was done by leaf-rub method, using bacterial suspension at 107 cells per milliliter which was the lowest concentration to cause highest disease severity. A total of 8357 Mon Noi gamma irradiated plantlets in 7-11 generations were screened for bacterial blight disease resistance. Eighteen plants survived and free from bacterial contamination. These surviving plants were in vitro rapid multiplication then screened for disease resistance in greenhouse. At present, only 4 lines from 18 plants are selected

  3. Induced Mutation on Jatropha (Jatropha Curcas L.) for Improvement of Agronomic Characters Variability

    International Nuclear Information System (INIS)

    Induced mutation can be used for improving quality in term of seed production, oil content in seed and early maturity of Jatropha with the aim for biodiesel in Indonesia. The doses of 10, 15, 20, and 25 Gy of gamma applied to cuttings was able to increase genetic variability in vegetatively propagated plants of Jatropha at M1V1 (mutant-1 vegetative-1) generation. Selection for desirable trait will be done at M1V2 (mutant-1 and vegetative-2) generation until homogenous plants obtained. Gamma rays at dose of 20 to 25 Gy damaged several genes controlling growth and development on Jatropha which was shown by dwarf and poor plant growth compared to control (plant without irradiation). Irradiation with the dose of 10 Gy raised genetic variability on plant development which was identified with early maturity. 100 seeds weight was 30% over control, and the number of branch growth was good. (author)

  4. Use of Gamma rays to induce mutations in four pea (Pisum sativum L.) cultivars

    International Nuclear Information System (INIS)

    The study reports a 3-step optimization to find out the effects of cytokinins BAP and TDZ on seed germination and g rays to induce mutations in 4 pea cultivars: Winner, Sprinter, Bolero and Karina. It was observed that germination was independent of the dose of g rays and was mainly affected by the germination capability of the genotypes and doses of BAP and TDZ in the germination medium. Seed germination was better on germination medium containing 50 µM BAP than 10 µM TDZ. Variable rooting was observed on shoots obtained from non-irradiated seeds germinated on MS medium containing 50 µM BAP. However, shoots of 2 cv. Winner irradiated with 60 Gy and Karina irradiated with 140 Gy g rays and germinated on 50 µM BAP showed reduced rooting. Abbreviations: g radiations: gamma radiations, BAP: 6 Benzylaminopurine, TDZ: Thidiazuron, NAA: a Naphthalene acetic acid, IBA: Indole 3 butyric acid. (author)

  5. Induced Mutation on Jatropha (Jatropha Curcas L. for Improvement of Agronomic Characters Variability

    Directory of Open Access Journals (Sweden)

    Ita Dwimahyani

    2004-07-01

    Full Text Available Induced mutation can be used for improving quality in term of seed production, oil content in seed and early maturity of Jatropha with the aim for bio_diesel in Indonesia. The doses of 10, 15,20, and 25 Gy of gamma applied to cuttings was able to increase genetic variability in vegetatively propagated plants of Jatropha at M1V1 (mutant-vegetative-1 generation. Selection for desirable trait will be done at M1 V2 (mutant-1 and vegetative-2 generation untill homogenous plants obtained. Gamma rays at dose of 20 to 25 Gy damaged several genes controlling growth and development on Jatropha which was shown by dwarf and poor plant growth compared to control (plant without irradiation. Irradiation with the dose of 10 Gy raised genetic variability on plant development which was identified with early maturity, 100 seeds weight was 30% over control, and the number of branch growth was good

  6. The use of induced mutation combined with crossing in high quality rice breeding

    Energy Technology Data Exchange (ETDEWEB)

    Do Huu At; Bui Huy Thuy; Nguyen Van Bich; Tran Duy Quy [Agricultural Genetics Institute, Division of Genetics and Hybrid Rice Technology, Hanoi (Viet Nam); Nguyen Minh Cong [Hanoi No. 1 Teacher Training Univ., Department of Genetics (Viet Nam)

    2001-03-01

    The high quality rice varieties: Tam thom mutant rice Var., DT17 rice Var, DT21 glutinous rice Var were formed by induced mutation combined with crossing. Tam thom mutant rice Var. lost photosensitivity, could be planted 2 crops/year. DT17 rice Var with high yielding capacity, suitable for growth on lowland in summer crop, is replacing step-by-step Moctuyen rice Var. in North Vietnam. DT21 glutinous rice Var. could be planted 2 crops/year and had short growth duration, average yield was 4.0-4.5 tons/ha. These three ones had good quality, soft and scent cooked rice, suitable for customers and export requirements. Tam thom mutant rice Var. DT17 rice Var., DT21 and glutinous rice Var. were adopted for regional production by Ministry of Agriculture and Rural Development and allowed to be in trial production. (author)

  7. Solar and UVC-induced mutation in human cells and inhibition by deoxynucleosides

    International Nuclear Information System (INIS)

    Optimum conditions were established for quantitating the induction of hypoxanthine guanine phosphoribosyl transferase-deficient (HGPRT-mutants in HeLa cells and a human amelanotic melanoma cell line (MM96L). Compared at a fluence of equal toxicity, noon sunlight in summer was slightly more mutagenic in MM96L than in HeLa cells. UVC exhibited similar mutagenicity as equitoxic sunlight in HeLa but was 8-fold more effective in MM96L than equitoxic sunlight. Addition of a mixture of deoxyguanosine, deoxyadenosine, deoxycytidine and thymidine to the culture medium during the 7-day expression period following irradiation gave a 3-fold reduction in the UVC-induced mutation frequency of MM96L but not HeLa cells. The results suggest that these melanocytic cells are highly susceptible to mutagenesis by short wavelength UV, in a mechanism sensitive to deoxynucleosides. (author). 21 refs.; 3 figs.; 1 tab

  8. Mutated recombinant human glucagon-like peptide-1 induces differentiation of PC12 cells

    Institute of Scientific and Technical Information of China (English)

    Jin Wu; Lan Zhang; Zhongwei Sun; Gang Huang; Jing Huang; Bing Mei

    2011-01-01

    "Glucagon-like peptide-1 (GLP-1) and its long-acting analogues have neuroprotective and neurotrophic properties and are emerging as potential treatments for neurodegenerative diseases. Its short half-life has limited the application of GLP-1 in the clinic. We generated a mutated form of human GLP-1 (mGLP-1) using site-directed mutagenesis and gene recombination techniques, and found that these modifications significantly prolonged the biological half-life of GLP-1 compared with native GLP-1 (nGLP-1). This study investigated the role of mGLP-1 on inducing PC12 cell differentiation. mGLP-1 induced PC12 cell differentiation with neurite outgrowth and increased the expression of growth-associated protein-43 and neuronal class III ?-tubulin, and significantly increased cyclic adenosine monophosphate level. No significant difference was found between mGLP-1 and nGLP-1. The results indicate that mGLP-1 activates the GLP-1 receptor, induces PC12 cell differentiation, and has neurotrophic effects.

  9. Improvement of new and traditional industrial crops by induced mutations and related biotechnology

    International Nuclear Information System (INIS)

    Industrial crops are an important source of income for many small landholders in developing countries and contribute directly or indirectly to food security in rural areas. Crop diversification, finding alternative crops, development of new uses for existing crops and introduction of new crops are important components in the efforts to meet the demand for food, pharmaceuticals, chemical raw materials, fibres and fuel in developing and developed countries. Plant breeding efforts combining genetic resources and induced mutations using classical, in vitro and innovative molecular approaches have been responsible for much of the development of industrial crops. This co-ordinated research project (CRP) was initiated in 1994. It focused on developing mutagenesis approaches for previously unstudied species, screening procedures for agricultural and industrial requirements and suitable genotypes of traditional industrial crops adapted to new areas and for new needs. The industrial crops selected for improvement under this CRP were oilseeds and fibre plants. The potential of induced mutations to affect critical steps in various biosynthetic pathways leading to oil quality and other metabolic modifications was investigated. The success of this CRP is evidenced by the application of mutation techniques, in combination with in vitro and molecular techniques in genetic improvement of oilseed crops such as soybean, rapeseed, sunflower, linseed, cuphea, meadowfoam and fibre plants such as cotton and jute. As a result, improved breeding lines are available in all the industrial crops that the CRP focused on. Novel oil types were developed in cuphea with potential use as a renewable, economical and safe energy source and in linseed with increased levels of saturated fatty acids. Genes of fatty acid synthesis were isolated from one species and used for modification of quality of other oilseeds. Disease and pest resistance was improved in oilseeds and fibre crops through transgenesis

  10. Absence of p53 gene mutations in mice colon pre-cancerous stage induced by o-nitrotoluene

    Directory of Open Access Journals (Sweden)

    Nahed A Hussien

    2014-01-01

    Conclusion: The results from the present study indicate that point mutations in the p53 gene, in the coding region (exons 5-8 and outside it (exons 10, 11, are not involved in the development of the colon precancerous stage induced by o-nt in mice.

  11. Comparative analysis of charged particle-induced autosomal mutations in murine cells and tissues

    Science.gov (United States)

    Kronenberg, Amy; Gauny, Stacey; Turker, Mitchell; Dan, Cristian; Kwoh, Ely

    exposed to 2 Gy of Fe ions. Mutant spectra were analyzed via PCR using a series of heterozygous markers along mouse chromosome 8. Cytotoxicity assays were performed immediately after Fe ion exposure of cells from two primary clones. Cells irradiated in vitro demonstrated a dose-dependent decrement in cloning efficiency with no evidence of a shoulder. The results demonstrate the two clones behave similarly (unpaired t-test, p>0.3) with a D0 of 84.3 cGy for the combined data set. Mutation data were obtained using cells from one of the primary clones. In three experiments, we observed a linear dose-response for Aprt mutation with an induced mutant frzction of 1.06 x 10-3 /Gy. Kidney epithelial cells irradiated in vivo and incubated for 2-4 months in situ prior to harvest also showed an exponential reduction of cloning efficiency. Cells harvested 8-10 months postirradiation showed evidence of recovery for doses up to 1.5 Gy, but there was no improvement in cloning efficiency for kidney cells exposed to 2 Gy Fe ions in vivo evaluated at the late time point. Results for Aprt mutation induction in vivo indicated considerable inter-animal variation within each dose group (0, 1.0, 1.5 and 2 Gy). Fe ion exposures were mutagenic to the kidney, even at the lowest dose (p<0.01). A comparison of the mutant frequency results at the two harvest times indicates that the dose response did not vary with incubation time in vivo. Analysis of the pooled data from the 2-4 months harvests and the 8-10 month harvests indicated an increase in mutant frequency of 1.49 fold per Gy (p=0.01, CI 1.11-2.01). Molecular analysis of Aprtdeficient cells collected after a 2 Gy exposure to Fe ions in vitro showed an increased proportion of mutants arising via interstitial deletion or mitotic recombination, with an indication of an increase in chromosome loss. Similar results have been obtained for Aprt mutants isolated from mice exposed to 2 Gy of Fe ions, as compared with mutants collected from sham

  12. Absence of missense mutations in activated c-myc genes in avian leukosis virus-induced B-cell lymphomas

    International Nuclear Information System (INIS)

    The authors determined the nucleotide sequences of two independent DNA clones which contained the activated c-myc genes from avian leukosis virus-induced B-cell lymphomas. Neither of these c-myce genes contained missense mutations. This strongly supports the notion that the c-myc photo-oncogene in avian leukosis virus-induced B-cell lymphomas can be oncogenically activated by altered expression of the gene without a change in the primary structure of the gene product

  13. Absence of missense mutations in activated c-myc genes in avian leukosis virus-induced B-cell lymphomas.

    OpenAIRE

    Hahn, M; Hayward, W S

    1988-01-01

    We have determined the nucleotide sequences of two independent DNA clones which contained the activated c-myc genes from avian leukosis virus-induced B-cell lymphomas. Neither of these c-myc genes contained missense mutations. This strongly supports the notion that the c-myc proto-oncogene in avian leukosis virus-induced B-cell lymphomas can be oncogenically activated by altered expression of the gene without a change in the primary structure of the gene product.

  14. Absence of missense mutations in activated c-myc genes in avian leukosis virus-induced B-cell lymphomas

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, M.; Hayward, W.S.

    1988-06-01

    The authors determined the nucleotide sequences of two independent DNA clones which contained the activated c-myc genes from avian leukosis virus-induced B-cell lymphomas. Neither of these c-myce genes contained missense mutations. This strongly supports the notion that the c-myc photo-oncogene in avian leukosis virus-induced B-cell lymphomas can be oncogenically activated by altered expression of the gene without a change in the primary structure of the gene product.

  15. A role for sunlight in skin cancer: UV-induced p53 mutations in squamous cell carcinoma

    International Nuclear Information System (INIS)

    Sunlight is a carcinogen to which everyone is exposed. Its UV component is the major epidemiologic risk factor for squamous cell carcinoma of the skin. Of the multiple steps in tumor progression, those that are sunlight-related would be revealed if they contained mutations specific to UV. In a series of New England and Swedish patients, the authors find that 14/24 (58%) of invasive squamous cell carcinomas of the skin contain mutations in the p53 tumor suppressor gene, each altering the amino acid sequence. Involvement of UV light in these p53 mutations is indicated by the presence in three of the tumors of a CC → TT double-base change, which is only known to be induced by UV. UV is also implicated by a UV-like occurrence of mutations exclusively at dipyrimidine sites, including a high frequency of C → T substitutions. p53 mutations in internal malignancies do not show these UV-specific mutations. The dipyrimidine specificity also implicates dipyrimidine photoproducts containing cytosine as oncogenic photoproducts. They believe these results identify a carcinogen-related step in a gene involved in the subsequent human cancer

  16. Breeding sesame for diseases and shatter resistant high yielding varieties with induced mutations

    International Nuclear Information System (INIS)

    ''Suwon 144'', derived from the cross between ''Danbaeckkae'' and mutant MY-74-2 and in spite of its higher yield and quality compared to the check variety, did not pass the nomination to the Committee of Main Crops New Varieties under the Ministry of Agriculture and Forestry, due to the decision of the committee to limit the number of new varieties in sesame as a minor crop in Korea. ''Suwon 144'' will be released again for a fifth year to RYT in 1998. 5,282 cross combinations and 4,341 lines including 1,388 crossings of F1 were crossed and released to the experimental field of NCES in 1997. Mutants and their cross combinations were released and constituted more than half among them. Seeds of ''Suwon 152'' were treated with NaN3 and tested for germinability. The other seeds were released and harvested in the experimental field and 419 mutant lines were selected among all the mutant lines. Mutants or materials from cross breeding with mutants occupied 71% (675) among a total of 952 promising lines in yield trials of OYT, PYT, AYT and RYT. For variability of NaN3 induced genetic male sterile (GMS) mutants and development of restorer/s of GMS, GMS lines were planted, and male sterility (MS) expression evaluated on each line. The selected 4 MS lines with 50% MS were crossed in 22 combinations with 7 recommended varieties. For development of genic-cytoplasmic MS (GCMS) using NaN3 induced GMS mutants, 40 recommended local Korean and introduced cultivars were crossed in 57 combinations with 4 selected GMS lines expressing 50% male sterility. Various and many sources of unique characteristics have been continuously created through induced mutations, such as determinate; dwarf, lodging,- Phytophthora blight- and shatter- resistant; indehiscent, seamless, taller, stronger thick stems, dense capsule bearing type, semi-dwarf, better maturity, male sterility, smaller seeds, pure white seed coat color and high yields. Lines with these induced desirable characteristics were

  17. CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Shin, Sung-Eun; Lim, Jong-Min; Koh, Hyun Gi; Kim, Eun Kyung; Kang, Nam Kyu; Jeon, Seungjib; Kwon, Sohee; Shin, Won-Sub; Lee, Bongsoo; Hwangbo, Kwon; Kim, Jungeun; Ye, Sung Hyeok; Yun, Jae-Young; Seo, Hogyun; Oh, Hee-Mock; Kim, Kyung-Jin; Kim, Jin-Soo; Jeong, Won-Joong; Chang, Yong Keun; Jeong, Byeong-Ryool

    2016-01-01

    Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including "safe harboring" techniques shown in other organisms. PMID:27291619

  18. Gamma-Ray Induced Mutations in Soybean [Glycine max (L.) Merill] for Yield-Contributing Traits

    International Nuclear Information System (INIS)

    Attempts were made to induce genetic variability in yield contributing traits in soybean [Glycine max (L) Merrill] employing gamma radiation. Germplasm of a locally adapted cultivar of soybean, MACS-450 was irradiated with different doses (10, 20, 30, and 40 kR) of Gamma-rays and sown in the field during the kharif season of 2006. M2 progeny was raised from the M1 seeds, and was screened for yield contributing traits. The M2 progeny raised from 30kR dose of gamma radiation exhibited several induced mutations for yield contributing traits. Important among them was a High-yielding mutant, of which about 10 mutant plants were obtained in the M2 progeny. These High-yielding mutants were all uniformly tall and showed a two-fold increase in plant height. They produced double the number of pods per plant and thrice the yield per plant as compared to control. No change in pod length and number of seeds per pod were observed between the control and High-yielding mutant plants, except for the 100 seed weight, which was almost 1.5 times higher compared to the control. These mutants seem to be very promising in increasing the yield of soybean. (author)

  19. CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii

    Science.gov (United States)

    Shin, Sung-Eun; Lim, Jong-Min; Koh, Hyun Gi; Kim, Eun Kyung; Kang, Nam Kyu; Jeon, Seungjib; Kwon, Sohee; Shin, Won-Sub; Lee, Bongsoo; Hwangbo, Kwon; Kim, Jungeun; Ye, Sung Hyeok; Yun, Jae-Young; Seo, Hogyun; Oh, Hee-Mock; Kim, Kyung-Jin; Kim, Jin-Soo; Jeong, Won-Joong; Chang, Yong Keun; Jeong, Byeong-ryool

    2016-01-01

    Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including “safe harboring” techniques shown in other organisms. PMID:27291619

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

    International Nuclear Information System (INIS)

    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 PO43- allosteric site where PO43- 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.

  1. Comparative analysis of charged particle-induced autosomal mutations in murine cells and tissues

    Science.gov (United States)

    Kronenberg, Amy; Gauny, Stacey; Turker, Mitchell; Dan, Cristian; Kwoh, Ely

    exposed to 2 Gy of Fe ions. Mutant spectra were analyzed via PCR using a series of heterozygous markers along mouse chromosome 8. Cytotoxicity assays were performed immediately after Fe ion exposure of cells from two primary clones. Cells irradiated in vitro demonstrated a dose-dependent decrement in cloning efficiency with no evidence of a shoulder. The results demonstrate the two clones behave similarly (unpaired t-test, p>0.3) with a D0 of 84.3 cGy for the combined data set. Mutation data were obtained using cells from one of the primary clones. In three experiments, we observed a linear dose-response for Aprt mutation with an induced mutant frzction of 1.06 x 10-3 /Gy. Kidney epithelial cells irradiated in vivo and incubated for 2-4 months in situ prior to harvest also showed an exponential reduction of cloning efficiency. Cells harvested 8-10 months postirradiation showed evidence of recovery for doses up to 1.5 Gy, but there was no improvement in cloning efficiency for kidney cells exposed to 2 Gy Fe ions in vivo evaluated at the late time point. Results for Aprt mutation induction in vivo indicated considerable inter-animal variation within each dose group (0, 1.0, 1.5 and 2 Gy). Fe ion exposures were mutagenic to the kidney, even at the lowest dose (pvivo. Analysis of the pooled data from the 2-4 months harvests and the 8-10 month harvests indicated an increase in mutant frequency of 1.49 fold per Gy (p=0.01, CI 1.11-2.01). Molecular analysis of Aprtdeficient cells collected after a 2 Gy exposure to Fe ions in vitro showed an increased proportion of mutants arising via interstitial deletion or mitotic recombination, with an indication of an increase in chromosome loss. Similar results have been obtained for Aprt mutants isolated from mice exposed to 2 Gy of Fe ions, as compared with mutants collected from sham-irradiated mice. Taken together, the results to date demonstrate that Fe ions are mutagenic to

  2. Genomics meets induced mutations in citrus: identification of deleted genes through comparative genomic hybridization

    International Nuclear Information System (INIS)

    We report on the use of genomic approaches to identify pivotal genes in induced citrus mutants. Citrus is the most economically important fruit crop in the world while Spain is the first fresh citrus producer. The survival of the Citrus industry is critically dependent on genetically superior cultivars but improvements in fruit quality traits through traditional techniques are extremely difficult due to the unusual combination of biological characteristics of citrus. Genomic science, however, holds promise of improvements in breeding. In this work, we reported the successful identification of genes included in hemizygous deletions induced by fast neutron irradiation on Citrus clementina. Microarray-based CGH was used to identify underrepresented genes in a citrus mutant that shows color break delay. Subsequent confirmation of gene doses through quantitative PCR and comparison of best hits of putative deleted citrus genes against annotated genomes from other eudicots, specially poplar, enabled the prediction that these genes were clustered into a 700 kb fragment. The availability of Citrus BAC end sequences helped to draw a partial physical map of the deletion. Furthermore, gene content and order in the deleted segment was established by PCR location of gene hits on the physical map. Finally, a lower chlorophyll a/b ratio was found in green tissues from the mutant, an observation that can be related to the hemizygous deletion of a ClpC-like gene, coding a putative subunit of a multifunctional protease complex located into the chloroplast. Analysis of gene content and order inside this Citrus deletion led to the conclusion that microsynteny and local gene colinearity with Populus trichocarpa were higher than with the phylogenetically closer Arabidopsis thaliana genome. In conclusion, a combined strategy including genomics tools and induced citrus mutations has been proved to be a successful approach to identify genes with major roles in citrus fruit development

  3. Genomics Meets Induced Mutations in Citrus: Identification of Deleted Genes Through Comparative Genomic Hybridization

    International Nuclear Information System (INIS)

    We report on the use of genomic approaches to identify pivotal genes in induced citrus mutants. Citrus is the most economically important fruit crop in the world and Spain is the first fresh citrus producer. The survival of the citrus industry is critically dependent on genetically superior cultivars but improvements in fruit quality traits through traditional techniques are extremely difficult due to the unusual combination of biological characteristics of citrus. Genomic science, however, holds promise of improvements in breeding. In this work, we reported the successful identification of genes included in hemizygous deletions induced by fast neutron irradiation on Citrus clementina. Microarray-based CGH was used to identify underrepresented genes in a citrus mutant that shows color break delay. Subsequent confirmation of gene doses through quantitative PCR and comparison of best hits of putative deleted citrus genes against annotated genomes from other eudicots, specially poplar, enabled the prediction that these genes were clustered into a 700 kb fragment. The availability of Citrus BAC end sequences helped to draw a partial physical map of the deletion. Furthermore, gene content and order in the deleted segment was established by PCR location of gene hits on the physical map. Finally, a lower chlorophyll a/b ratio was found in green tissues from the mutant, an observation that can be related to the hemizygous deletion of a ClpC-like gene, coding a putative subunit of a multifunctional protease complex located into the chloroplast. Analysis of gene content and order inside this Citrus deletion led to the conclusion that microsynteny and local gene colinearity with Populus trichocarpa were higher than with the phylogenetically closer Arabidopsis thaliana genome. In conclusion, a combined strategy including genomics tools and induced citrus mutations has been proved to be a successful approach to identify genes with major roles in citrus fruit development

  4. A mutation in the insulin 2 gene induces diabetes with severe pancreatic β-cell dysfunction in the Mody mouse

    OpenAIRE

    Jie WANG; Takeuchi, Toshiyuki; Tanaka, Shigeyasu; Kubo, Suely-Kunimi; Kayo, Tsuyoshi; Lu, Danhong; Takata, Kuniaki; Koizumi, Akio; Izumi, Tetsuro

    1999-01-01

    The mouse autosomal dominant mutation Mody develops hyperglycemia with notable pancreatic β-cell dysfunction. This study demonstrates that one of the alleles of the gene for insulin 2 in Mody mice encodes a protein product that substitutes tyrosine for cysteine at the seventh amino acid of the A chain in its mature form. This mutation disrupts a disulfide bond between the A and B chains and can induce a drastic conformational change of this molecule. Although there was no gross defect in the ...

  5. A novel approach for rapid detection of X-ray irradiation induced mtDNA D310 mutation

    International Nuclear Information System (INIS)

    Human breast cancer cell line MCF-7 was irradiated with 4 Gy X-ray, collected at 0, 2, 4, 8, 16, 24, 48, 72, 144 h after irradiation,respectively. Whole genome DNA including mtDNA were extracted at each time point, and amplified by polymerase chain reaction (PCR). Then the PCR product was subjected to BSAXI digestion, all of digestion product then underwent a brief electrophoresis. Results showed D310 mutation can be induced by 4 Gy X-ray irradiation and D310 mutation can overwhelm the normal phenotype 144 h after irradiation. (authors)

  6. Analysis of dominant and recessive sex-linked lethal mutations induced by low radiation doses in genetically different strains of Drosophila melanogaster w and MS

    International Nuclear Information System (INIS)

    Frequencies of induced recessive sex-linked lethal mutations (RSLLM) and dominant lethal mutations (DLM) were analyzed in genetically different Drosophila melanogaster strains w and MS after their exposure to radiation on radioactive soil in laboratory conditions. The RSLLM test applied to males after their 14-day radiation exposure yielded controversial results. An analysis of induced and spontaneous DLM demonstrated an increase in the frequency of early embryonic lethal mutations in the experiment (radiation exposure) in comparison with the control (spontaneous mutation rate) in both strains examined

  7. ATM dependent low-dose hyper-radiosensitivity in mutation induced by heavy ions in mammalian cells

    International Nuclear Information System (INIS)

    On the basis of our last year's work that proved the existence of Low dose Hyper-radiosensitivity (HRS) and later appeared radioresistance (termed Induced radioresistance (IRR)) in normal human skin fibroblast cells exposed to carbon ions irradiation with the endpoints of survival and mutation, we further study the role of ataxia telangiectasia mutated (ATM) kinase, which has been indicated to work in the mechanism of HRS/IRR by low linear energy transfer (LET) irradiation. Normal human fibroblast cells were pretreated with stimulator for ATM kinase, chloroquine, or with ATM inhibitor, KU55933 prior to carbon irradiation, survival fraction and HPRT mutation frequency were measured to test the existence of HRS/IRR. Interestingly there was no HRS/IRR in either ATM stimulator or inhibitor pretreatment. The western blot suggest a dose-dependent increase of ATM kinase activity, which further confirm the role of ATM in the mechanism of HRS/IRR. (author)

  8. Pathogenicity of missense mutations in SURF1 deficiency inducing the Leigh syndrome. Importance in diagnosis.

    Science.gov (United States)

    Dubot, A; Hervouet, E; Mandon, G; Zabot, M T; Godinot, C

    2004-06-01

    Leigh syndrome with cytochrome oxidase (COX) deficiency has been associated with SURF1 mutations. For patient diagnosis, distinction between neutral polymorphisms and pathogenic missense SURF1 mutations in Leigh syndrome is essential. We show that several missense SURF1 mutations did not allow a stable protein to be expressed. Absence of immunologically reactive SURF1 is, therefore, helpful to demonstrate their pathogenicity. In addition, we show that out of two previously described missense mutations housed by the same allele, only one, the T737 C was pathogenic. Indeed, transfection of T737 C mutated SURF1 in SURF1-deficient cells did not restore normal SURF1 stability and COX activity. On the contrary, the G604 C-mutated SURF1 did it and, hence, is a neutral variant. PMID:16120373

  9. The use of radiations to induce useful mutations in fruit trees

    International Nuclear Information System (INIS)

    The researches carried out at Casaccia in this field had covered the problems of technique of mutagenic treatment, mechanism of mutation induction and methodology of somatic mutation isolation. To enhance the efficiency of somatic mutation induction several conditions during and after the treatment have been studied. More experience has been gained with regard to the induction of somatic mutation which raises from genetical event or by tissue arrangement of a chimaeric shoot apex. To increase the size of mutated sector treatment have been carried out on the primordia in a very early stages and to improve the methodology of somatic mutation special techniques have been adapted of handling the material in the propagation. Possibility for early detection of mutants has been explored in cherry by establishing a correlation between mutants and hormonal content. By using the above mentioned techniques, useful mutants have been isolated in cherries, grapes, olives and peaches. (author)

  10. Closing Statement [International Symposium on Induced Mutations in Plants, Vienna (Austria), 12-15 August 2008

    International Nuclear Information System (INIS)

    This Symposium was the eighth in the Joint FAO/IAEA Programme's Symposium series, dedicated to harnessing and disseminating information on current trends in induced mutagenesis in plants. The first meeting was held in 1969, and the most recent in 1995. Thirteen years on, in a climate of increasing food shortages, it was high time that this Symposium was held. Although mutation breeding is 80 years old, as we just heard, new applications continue to be found and will continue to be developed. The application of mutation techniques, such as 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 in countries throughout the world. The importance of these techniques is reflected in the large number of participants gathered here: a total of 500 delegates from 81 countries that are IAEA and FAO Member States and nine organizations. I believe that the extensive scientific programme, which included 126 oral and 252 poster presentations, is an indicator of the range, depth and relevance of the topic. Being aware of the scientific nature of this Symposium, let me however, say a few words on behalf of the IAEA's TC Programme. The programme provided financial support to several participants to attend this Symposium, but more importantly, many of the participants have been trained through the Technical Cooperation Programme, supported by the FAO/IAEA Joint Division. Technical training of this sort is a core component in the implementation of the IAEA mandate 'Atoms for Peace, Health and Prosperity'. Over the past five years, food and agriculture has accounted for one of the largest areas of the IAEA Technical Cooperation Programme around the world, and projects in this area are on the increase in the 2009-2011 programme cycle. The Agency's combination of technical and managerial expertise offers Member States significant benefits in the formulation and

  11. Mutations in uvrD induce the SOS response in Escherichia coli.

    OpenAIRE

    Ossanna, N; Mount, D W

    1989-01-01

    We have isolated three new mutations in uvrD that increase expression of the Escherichia coli SOS response in the absence of DNA damage. Like other uvrD (DNA helicase II) mutants, these strains are sensitive to UV irradiation and have high spontaneous mutation frequencies. Complementation studies with uvrD+ showed that UV sensitivity and spontaneous mutator activity were recessive in these new mutants. The SOS-induction phenotype, however, was not completely complemented, which indicated that...

  12. Cellular and Deafness Mechanisms Underlying Connexin Mutation-Induced Hearing Loss – A Common Hereditary Deafness

    OpenAIRE

    Wingard, Jeffrey C.; Zhao, Hong-Bo

    2015-01-01

    Hearing loss due to mutations in the connexin gene family, which encodes gap junctional proteins, is a common form of hereditary deafness. In particular, connexin 26 (Cx26, GJB2) mutations are responsible for ~50% of non-syndromic hearing loss, which is the highest incidence of genetic disease. In the clinic, Cx26 mutations cause various auditory phenotypes ranging from profound congenital deafness at birth to mild, progressive hearing loss in late childhood. Recent experiments demonstrate th...

  13. Induced mutations in tomato SlExp1 alter cell wall metabolism and delay fruit softening.

    Science.gov (United States)

    Minoia, Silvia; Boualem, Adnane; Marcel, Fabien; Troadec, Christelle; Quemener, Bernard; Cellini, Francesco; Petrozza, Angelo; Vigouroux, Jacqueline; Lahaye, Marc; Carriero, Filomena; Bendahmane, Abdelhafid

    2016-01-01

    Fruit ripening and softening are key traits for many fleshy fruit. Since cell walls play a key role in the softening process, expansins have been investigated to control fruit over ripening and deterioration. In tomato, expression of Expansin 1 gene, SlExp1, during fruit ripening was associated with fruit softening. To engineer tomato plants with long shelf life, we screened for mutant plants impaired in SlExp1 function. Characterization of two induced mutations, Slexp1-6_W211S, and Slexp1-7_Q213Stop, showed that SlExp1 loss of function leads to enhanced fruit firmness and delayed fruit ripening. Analysis of cell wall polysaccharide composition of Slexp1-7_Q213Stop mutant pointed out significant differences for uronic acid, neutral sugar and total sugar contents. Hemicelluloses chemistry analysis by endo-β-1,4-d-glucanase hydrolysis and MALDI-TOF spectrometry revealed that xyloglucan structures were affected in the fruit pericarp of Slexp1-7_Q213Stop mutant. Altogether, these results demonstrated that SlExp1 loss of function mutants yield firmer and late ripening fruits through modification of hemicellulose structure. These SlExp1 mutants represent good tools for breeding long shelf life tomato lines with contrasted fruit texture as well as for the understanding of the cell wall polysaccharide assembly dynamics in fleshy fruits. PMID:26566837

  14. Induced mutations in ornamental plants by 'in vitro' irradiation of Petunia hybrida meristems

    International Nuclear Information System (INIS)

    In recent decades it has been observed that for the induction of mutation in ornamental plants we can obtain better results when the plants are irradiated in vegetative state and even better 'in vitro' that when its are irradiated 'in vivo'. In this work the possibilities are showed to avoid the best use of a new biotechnology: the gamma irradiations on the meristem 'in vitro'. A tissue culture method was described for the best vegetative propagation of Petunia hybrid hort through morphogenesis induction of meristem. These were planted in the Murashige and Skoog's basic medium added with BAP and ANA. The pH was adjusted to 6.5 prior autoclaving at 121 Centigrade degree and 1.1 Kg/ cm2 for 15 minutes. Latter the meristem of plantules in immature and mature physiology stated were irradiated with gamma ray doses ranging from 1.0 at 10.0 Gy. The meristem were then subcultived aseptically with the following results: 1) The immature stage was higher radio sensibilities. 2) The LD 50 for the matured plants was to ranged from 1.0 at 9.0 Gy. and immature 1.0 at 8.0 Gy. 3) The better doses was at 7.5 Gy. 4) The meristem gamma irradiation at 7.5 Gy. showed in the first culture: the adventitious bud induced and the multi meristem formation. 5) In the second cultured the results reveals the 'variegadas' plants formations and the new purples flowers. (Author)

  15. Improvement of banana (Musa cvs.) through in vitro culture techniques and induced mutations

    International Nuclear Information System (INIS)

    Rapidly multiplying shoot tip cultures were established from meristem explants of banana (Musa cvs.). Banana cultivars were successfully propagated on modified Murashige and Skoog medium with 4.5 mg/l BAP. Roots were induced on plantlets cultured on 1/2 strength MS medium containing 0.20 mg/l IBA. Plantlets were acclimatized and transferred to soil for further evaluation. Proembryogenic calli were initiated from basal leaf sheaths and rhizome tissue cultured on SH medium with 6.63 mg/l dicamba. Protoplasts were isolated form rhizome tissue using an enzyme solution containing 3% cellulase R-10, 1% macerozyme R-10 and 1% pectinase. Efforts are in progress to regenerate plants via somatic embryogenesis and from isolated protoplasts. A mutation induction experiment was carried out by irradiating vegetative shoot apices at 5, 10, 15 and 20 Gy using a 60Co source. Radiosensitivity was assessed by determining the subsequent rate of shoot differentiation. (author). 19 refs, 1 fig., 1 tab

  16. Improvement of traditional local rice varieties through induced mutations using nuclear techniques

    International Nuclear Information System (INIS)

    'Improvement of local rice varieties for high yield, resistance to disease and insect pests (brown plant hopper and rice blast) and export quality through induced mutations for the Mekong Delta' started in 1993. After six years, it showed effecting on the field in the MD as well as at the south of Vietnam. TNDB-100 manifest very wide adaptation and yield stable variety. THDB is suitable for deepwater rice region, coastal area, where rice cultivation effected by acid sulphate and salinity conditions. Both varieties are good example for the method. Thank to good Co-operation from extension center from provinces, hundred classes of extension were organized to recommend to the farmers. And thank to the strongly supporting from IAEA so that nearly 400,000 ha of TNDB-100 occupied at the south of Vietnam as well as nearly 15,000 ha of THDB grown in the coastal as well as rainfed lowland rice areas at the South of Vietnam. To continue the rice improvement by this technique, seeds of six traditional local varieties were exposed under different dose of gamma rays to create new mutants. At present day hundred improved breeding lines were selected, a dozen of uniform lines were isolated and entranced the yield trail as well as regional testing program. From these improved varieties would be selected to contribute to the rice cultivation at the south of Vietnam in the next years. (author)

  17. Possible contribution of induced mutations on breaking the rice yield barrier

    International Nuclear Information System (INIS)

    At The World Rice Research Conference in Tsukuba, Japan, on 4 — 7 November 2004, there was an active discussion on how to increase the world rice yield production. Breeders agreed that after IR8, the yield potential of rice varieties could not increase drastically. From the breeding point of view, there were two approaches that already started in three to one decade ago, but it is still unfinished yet. These two approaches were to do breeding for hybrid rice varieties or breeding for new plant idiotype varieties. The idea to produce hybrid rice was stimulated by the success of hybrid corn, onion, and sorghum on commercial basis. Among the countries that are working for producing hybrid rice varieties, China was the leading one. China produced hybrid rice varieties and which are planted already in very large area. This success influenced other countries to do the same, including Indonesia. Now Indonesia has already released 11 hybrid rice varieties. Knowing so many characters that are already present in the rice collection, the idea to produce new plant idiotype appears. It seems not difficult to unite selected characters to become a new plant idiotype. In fact, however, up to now there are still a lot of obstacles that make those two approaches could not reach the real goal. This paper will discuss the possible contribution of induced mutations toward the success of these two approaches. (author)

  18. A Novel ENU-Induced Mutation in Myo6 Causes Vestibular Dysfunction and Deafness

    Science.gov (United States)

    Wong, Elaine Y. M.; Xu, Chelsea Y.; Brahmachary, Manisha; Xu, Pin-Xian

    2016-01-01

    Mouse N-ethyl-N-nitrosourea (ENU) mutagenesis has generated many useful animal models for human diseases. Here we describe the identification of a novel ENU-induced mouse mutant strain Turner (Tur) that displays circling and headtossing behavior and progressive hearing loss. Tur/Tur homozygous animals lack Preyer and righting reflexes and display severe headtossing and reaching response defect. We mapped the Tur mutation to a critical region of 11 cM on chromosome 9 that includes myosin VI. Direct sequence analysis revealed a c.820A>T substitution in exon 8 of the Myo6 gene that changes amino acid Asn200 to Ile (p.N200I) in the motor domain. Analysis of inner ear hair cells by immunohistochemistry, scanning electron microscopy and histology revealed degeneration of hair cells in the inner ear and structural malformation of the stereocilia in the cochlea of Turner homozygous mutant mice. Our data indicate that this novel mouse strain provides a useful model for future studies on the function of myosin VI in mammalian auditory and non-auditory systems and in human syndromes. PMID:27171474

  19. Reduced Tyk2 gene expression in β-cells due to natural mutation determines susceptibility to virus-induced diabetes.

    Science.gov (United States)

    Izumi, Kenichi; Mine, Keiichiro; Inoue, Yoshitaka; Teshima, Miho; Ogawa, Shuichiro; Kai, Yuji; Kurafuji, Toshinobu; Hirakawa, Kanako; Miyakawa, Daiki; Ikeda, Haruka; Inada, Akari; Hara, Manami; Yamada, Hisakata; Akashi, Koichi; Niho, Yoshiyuki; Ina, Keisuke; Kobayashi, Takashi; Yoshikai, Yasunobu; Anzai, Keizo; Yamashita, Teruo; Minagawa, Hiroko; Fujimoto, Shuji; Kurisaki, Hironori; Shimoda, Kazuya; Katsuta, Hitoshi; Nagafuchi, Seiho

    2015-01-01

    Accumulating evidence suggests that viruses play an important role in the development of diabetes. Although the diabetogenic encephalomyocarditis strain D virus induces diabetes in restricted lines of inbred mice, the susceptibility genes to virus-induced diabetes have not been identified. We report here that novel Tyrosine kinase 2 (Tyk2) gene mutations are present in virus-induced diabetes-sensitive SJL and SWR mice. Mice carrying the mutant Tyk2 gene on the virus-resistant C57BL/6 background are highly sensitive to virus-induced diabetes. Tyk2 gene expression is strongly reduced in Tyk2-mutant mice, associated with low Tyk2 promoter activity, and leads to decreased expression of interferon-inducible genes, resulting in significantly compromised antiviral response. Tyk2-mutant pancreatic β-cells are unresponsive even to high dose of Type I interferon. Reversal of virus-induced diabetes could be achieved by β-cell-specific Tyk2 gene expression. Thus, reduced Tyk2 gene expression in pancreatic β-cells due to natural mutation is responsible for susceptibility to virus-induced diabetes. PMID:25849081

  20. Antibody-induced down-regulation of a mutated insulin receptor lacking an intact cytoplasmic domain

    International Nuclear Information System (INIS)

    Insulin receptor down-regulation was studied in various Chinese hamster ovary (CHO) cell lines expressing transfected human insulin receptor cDNAs. In addition to a cell line expressing the normal receptor (CHO.T line), three lines expressing mutated receptors were studied: the CHO.T-t line, which expresses a receptor with a degraded cytoplasmic domain due to the removal of the C-terminal 112 amino acids, and the CHO.YF1 and CHO.YF3 lines, in which important autophosphorylation sites of the receptor kinase (tyrosines-1162 and -1163) have been replaced by phenylalanine. A monoclonal anti-receptor antibody, but not insulin itself, was found to down-regulate cell surface receptor levels in all four cell lines by 60-80% after 18-h treatment at 370C. Down-regulation of the CHO.T and CHO.T-t receptors occurred at similar antibody concentrations and with a similar time course, although the maximum level of CHO.T-t down-regulation (60%) was generally lower than the level of CHO.T down-regulation (80%). Pulse-chase labeling of these two cell types with [35S]methionine revealed that antibody treatment of both CHO.T and CHO.T-t cells resulted in a similar increase in the rate of degradation of mature receptor subunits. These results indicate that antibody-induced down-regulation of the insulin receptor in these cells can occur in the absence of various autophosphorylation sites of the receptor and that the mechanism of antibody-induced down-regulation is different from that for insulin

  1. Induced mutations in chickpea (Cicer arietinum L.) I. comparative mutagenic effectiveness and efficiency of physical & chemical mutagens

    International Nuclear Information System (INIS)

    Mutagenic effectiveness usually means the rate of mutation as related to dose. Mutagenic efficiency refers to the mutation rate in relation to damage. Studies on comparative mutagenic effectiveness and efficiency of two physical (gamma rays and fast neutrons) and two chemical mutagens (NMU and EMS) on two desi (G 130 & H 214), one kabuli (C 104) and one green seeded (L 345) chickpea (Cicer arietinum L.) have been reported. The treatments included three doses each of gamma rays (400, 500 and 600 Gy) and fast neutrons (5, 10 and 15 Gy) and two concentrations with two different durations of two chemical mutagens, NMU 0.01% 20h and 0.02% 8h) and EMS (0.1% 20h and 0.2% 8h). Results indicated that chemical mutagens, particularly NMU are not only more effective but also efficient than physical mutagens in inducing mutations in chickpea. Mutagenic effectiveness and efficiency showed differential behaviour depending upon mutagen and varietal type. Chemical mutagens were more efficient than physical in inducing cholorophyll as well as viable and total number of mutations. Among the mutagens NMU was the most potent, while in the physical, gamma rays were more effective. Out of four mutagens, NMU was the most effective and efficient in inducing a high frequency and wide spectrum of chlorophyll mutations in the M2 followed by fast neutrons. While gamma rays showed least effectiveness, EMS was least efficient mutagens. Major differences in the mutagenic response of the four cultivars were observed. The varieties of desi type were more resistant towards mutagenic treatment than kabuli and green seeded type

  2. Induced mutation in dwarf growth habits of apple trees by gamma rays and its evaluation in practical uses

    International Nuclear Information System (INIS)

    A series of mutation breeding experiments on apple has been made. The dwarf type mutants having dwarfing rootstock effects on top varieties were developed in the gamma field. In this paper, the induction efficiency that the desirable spur type mutants for top, and the effective dwarf type mutants for rootstocks are produced in a gamma field in comparison with acute irradiation, and some evaluation of the induced mutants for practical purposes are described. A large number of the spur type mutants of apple trees having dwarf growth habit and a desirable tree form for high density planting have been induced by chronic or acute irradiation of gamma-ray since 1962. The mutation with dwarf growth habit including spur types was detected in the grafts on the clonal rootstocks of Marubakaido Malus prunifolia. No useful mutation toward the trees with dwarf growth habit and favorable fruit quality was recognized in the mutants derived from acute irradiation. Chronic treatment has been conducted in the uninjurious area in the gamma field on settled trees. High mutability in the dwarf growth of aged resting buds of settled trees was examined by twice-repeated cutting back treatments. In conclusion, for the induction of useful mutants or effective dwarfing mutants as clonal rootstocks, the artificial mutation breeding with gamma-ray should be conducted under chronic conditions and by planned cutting back treatments, in order to avoid various chromosomal aberrations and intrasomatic selection. (Kato, T.)

  3. Gamma-ray induced mutations in Pisum arvense (L.s.s.)

    International Nuclear Information System (INIS)

    The subject of the studies was the progeny of seven lines of field pea, treated with gamma rays (at the doses of 1, 6, 12, 15, 50 kR) in the generations M2- M4. Of the total number of analysed 15630 plants 249 mutants have been isolated which constituted 1.59% of the total population. The mutation frequency was significantly different depending on the line under study and on the radiation dose. In the mutation spectrum lethal and semilethal mutations were prevalent. The cause of these phenomena were either chlorophyll aberrations or disturbances in the development, growth and morphology of plants. These mutations died in different periods of vegetation or did not come to flowering and died. A number of morphologic-developmental mutations have been isolated; their genotypes have been established, cytologically examined and characterized. Some of the isolated fertile mutations are similar to those obtained at other research centres (e.g., cirrhifolialis, viciaefolialis, fasciata), others seem to be original (eg. pumilio, celeriter crescens, gynaecei, multiplicis). It is necessary, however, to perform identification tests to introduce these mutations into the Pisum Genebank, the more so, as most of papers on mutations concerned edible and garden peas (P. sativum L.), and in our work we considered field forms (P. arvense L.s.s.). (author)

  4. Molecular nature of spontaneous and radiation-induced mutations with allelic loss in human cells

    International Nuclear Information System (INIS)

    An assay system was developed for dissecting the second step in loss of function mutations and for determining the potency of physical and chemical agents to produce such mutations. Results obtained suggest that somatic recombination and/or deletion occurs close to the border between the heterochromatic and euchromatic regions of chromosome 16q. (author)

  5. Presenilin-1 regulates induction of hypoxia inducible factor-1α: altered activation by a mutation associated with familial Alzheimer's disease

    OpenAIRE

    Sosa Miguel; De Gasperi Rita; Dracheva Stella; Elder Gregory A

    2010-01-01

    Abstract Background Mutations in presenilin-1 (Psen1) cause familial Alzheimer's disease (FAD). Both hypoxia and ischemia have been implicated in the pathological cascade that leads to amyloid deposition in AD. Here we investigated whether Psen1 might regulate hypoxic responses by modulating induction of the transcription factor hypoxia inducible factor 1-α (HIF-1α). Results In fibroblasts that lack Psen1 induction of HIF-1α was impaired in response to the hypoxia mimetic cobalt chloride, as ...

  6. Genetic analysis of wild-isolated Neurospora crassa strains identified as dominant suppressors of repeat-induced point mutation.

    OpenAIRE

    Bhat, Ashwin; Noubissi, Felicite K.; Vyas, Meenal; Kasbekar, Durgadas P

    2003-01-01

    Repeat-induced point mutation (RIP) in Neurospora results in inactivation of duplicated DNA sequences. RIP is thought to provide protection against foreign elements such as retrotransposons, only one of which has been found in N. crassa. To examine the role of RIP in nature, we have examined seven N. crassa strains, identified among 446 wild isolates scored for dominant suppression of RIP. The test system involved a small duplication that targets RIP to the easily scorable gene erg-3. We prev...

  7. Elastatinal and leupeptin: effects on u.v.-induced mutation and sister-chromatid exchanges in Chinese hamster cells

    International Nuclear Information System (INIS)

    Microbial protease inhibitors elastatinal and leupeptin were tested for cytotoxicity and for effects on spontaneous and u.v.-induced 6-thioguanine-resistant (6TGr) mutation and sister-chromatid exchange (SCE) in V79 Chinese hamster cells. Continuous treatment with elastatinal exhibited marked cytotoxicity, while leupeptin was almost non-cytotoxic. Elastatinal rapidly induced cytotoxic effects as a function of its concentration and time of exposure. Near maximum cytotoxicity was reached after exposure of 6-8 h and this was partially abolished by the presence of 2.5 micrograms cycloheximide per ml. Concentrations of either protease inhibitor which gave 60-80% survival had no appreciable effects on u.v. survival and frequencies of spontaneous and u.v.-induced 6TGr mutation and SCE. However, reconstruction experiments revealed that pretreatments of 6TGr and 6TGs (wild-type) cells with these inhibitors for 6 days tended to block metabolic co-operation in their co-cultures. Thus, elastatinal and leupeptin are neither clastogenic mutagenic by themselves, and do not alter mutation fixation and expression

  8. Modulation of radiation-induced mutation frequencies and DNA synthesis by deoxycytidine in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    The goal of this project is to elucidate and model the impact of perturbations in cellular metabolism on the cellular response to DNA damage. Previously reported experiments established roles for DNA synthesis and the inhibition of DNA synthesis in the expression of radiation-induced mutations. This year, these experiments were continued and the study was expanded. Two different Chinese hamster ovary (CHO) cell lines were examined. Experimental measurements were obtained for cells in one of two growth media: (1) medium A, which consisted of Ham's F-12 containing 10% fetal calf serum; or (2) medium B, which consisted of medium A containing 2 mm deoxycytidine (CdR). The presence of CdR differentially affected the nature of DNA replication, the inhibition of replication by radiation, and the corresponding mutation frequency responses. Results suggest that the effect of CdR on mutation-induction is not locus-specific. Moreover, the phenomenal reduction in the mutation response in the presence of CdR is also seen following exposure to ionizing radiation, which implies that the effect of CdR is not mutagen-specific. Time-dependent changes in profiles of pulse-labeled DNA on alkaline sucrose gradients were employed to measure and compare nascent DNA chain growth processes in the two media. Results suggest that a more rapid DNA chain elongation and/or replicon mutation rate occurs in cells in medium B. In contrast, the sedimentation of one pulse-labeled CHO cell line DNA is always greater when cells are grown in medium A. UV radiation appears to inhibit postirradiation replicon initiation events and results in reduced mutation frequencies when cells are grown in the medium that promotes the more rapid rate of polymerization

  9. Dominant male sterility in sorghum: effect of nuclear background on inheritance of tissue-culture-induced mutation.

    Science.gov (United States)

    Elkonin, Lev A

    2005-11-01

    Occurrence of genetic instability and formation of stable mutations are basic genetic processes. This study demonstrates that nuclear background may influence the formation of stable dominant nuclear gene of male sterility (MS) on the basis of unstable mutation, which was induced in tissue culture of the sorghum haploid (cv. Milo-145). The mutants with complete or partial MS segregated in variable ratios in the progenies of diploid regenerants were obtained from different experiments on cultivation of haploid tissues. In the Milo-145 genetic background the mutation demonstrated somatic instability and was gradually eliminated by self-pollination of partially sterile plants. Hybridization of the MS-plants with the sorghum line SK-723, a fertility-restorer of the cytoplasmic MS A1 (milo) type, maintained the induced mutation. By repeated backcrossing of MS-plants with SK-723, the male-sterile versions of this line (SK-723- Ms(tc)) have been created. In BC-generations, fertile, partially and completely sterile plants were observed. The MS-plants from BC-generations are proposed to contain a dominant gene Ms(tc) while fertile plants were ms(tc)/ms(tc) homozygotes. Crossing the original MS-plants with SK-723 was a key factor in stabilization of the Ms(tc) gene. Dominant expression of the Ms(tc) was observed in male-sterile versions of other sorghum lines created by backcrossing to SK-723- Ms(tc). The lines fertility-restorers for this mutation have been revealed. In the crosses of restored F1 hybrids with emasculated plants of the non-restoring line, the Ms(tc) has been transferred through the pollen and manifested in the F1 generation. The possibility of the Ms(tc) originating as a result of interaction of an unstable allele of the Milo-145 with the SK-723 genome is discussed. PMID:16205908

  10. Complete Spectrum of CRISPR/Cas9-induced Mutations on HBV cccDNA.

    Science.gov (United States)

    Seeger, Christoph; Sohn, Ji A

    2016-08-01

    Hepatitis B virus (HBV) causes chronic infections that cannot yet be cured. The virus persists in infected hepatocytes, because covalently closed circular DNA (cccDNA), the template for the transcription of viral RNAs, is stable in nondividing cells. Antiviral therapies with nucleoside analogues inhibit HBV DNA synthesis in capsids in the cytoplasm of infected hepatocytes, but do not destroy nuclear cccDNA. Because over 200 million people are still infected, a cure for chronic hepatitis B (CHB) has become one of the major challenges in antiviral therapy. As a first step toward the development of curative therapies, we previously demonstrated that the CRISPR/Cas9 system can be used to functionally inactivate cccDNA derived from infectious HBV. Moreover, some evidence suggests that certain cytokines might induce an APOBEC-mediated cascade leading to the destruction of cccDNA. In this report we investigated whether a combination of the two mechanisms could act synergistically to inactivate cccDNA. Using next generation sequencing (NGS), we determined the complete spectrum of mutations in cccDNA following Cas9 cleavage and repair by nonhomologous end joining (NHEJ). We found that over 90% of HBV DNA was cleaved by Cas9. In addition our results showed that editing of HBV DNA after Cas9 cleavage is at least 15,000 times more efficient that APOBEC-mediated cytosine deamination following treatment of infected cells with interferon alpha (IFNα). We also found that a previously used method to detect cytosine deaminated DNA, termed 3D-PCR, overestimates the amount and frequency of edited HBV DNA. Taken together, our results demonstrated that the CRISPR/Cas9 system is so far the best method to functionally inactivate HBV cccDNA and provide a cure for CHB. PMID:27203444

  11. M 127- A promising tomato variety developed through induced mutation technique

    International Nuclear Information System (INIS)

    Bacterial wilt (BW) is the most serious constraints for tomato cultivation in Sri Lanka. At present, the producers and consumers are more interested in yield and quality of produce. The objective of this study was to develop genotypes having BW resistance, high yield potential (>20 t/ha) with desirable fruit qualities. Application of induced mutations was practiced on Manik variety. It is a well adapted variety with BW resistance, large fruit size with low fruit weight (76 g) due to large empty locular cavities. Several beneficial mutants better than the parent variety were identified in M2 generation and confirmed in M4 generation. The most promising 05 mutants were evaluated for BW resistance, fruit quality and yield. During dry and wet seasons, the yield evaluation studies were conducted in research and farmer fields. The mutant M 127 gave significantly higher yields (32.2 t/ha) than the check variety T 245 (21.7 t/ha) during the both seasons. Bacterial wilt screening in the field and laboratory demonstrated that M 127 was moderately resistant. The National Coordinated Varietal Trials confirmed that it was a promising mutant under different Agro-ecological zones in both dry and wet seasons. On farm trials indicated that farmer acceptability was higher for the mutant than the check variety. The mutant M 127 possesses high fruit weight (158.6 g), red, slightly flattened firm fruits. It is highly acceptable for table purpose. In near future the mutant M 127 will be officially released to farmers and at present, it is utilized as a donor parent in the development of new HF3 hybrid under the heterosis breeding programme. (author)

  12. Evaluating and validating the protocol for gamma radiation induced mutations in floral distinct rosa spp

    International Nuclear Information System (INIS)

    Among the highly fragrant Rosa species, Rosa gruss an teplitz and Rosa centifolia have high value in terms of commercial importance and economical trade. However, the absence of floral diversification and diversity in color patterns in these species acts as limiting factors in floriculture trade of these species. In the present study, we aimed to induce mutations using gamma radiations up to 120 Gy to observe the rate and the correlated effects on the several plant traits in micropropagated shoot tips of Rosa gruss an teplitz and Rosa centifolia. Irradiated shoot tips were micropropagated for one culture cycle and were acclimatized in a green house after in vitro rooting. Plants of irradiated population at 60 and 30 Gy showed 78.12 and 38.50 percentage less culture rooting percentage age as well as 23.82 and 7 percentage less flower size as compared to non irradiated population of Rosa gruss an teplitz and Rosa centifolia respectively. Moreover, flower color component a* (+ redness - green, 36.16 and 27.16) and chroma (37.77 and 27.5) depicted minimum while L* (Lightness, 45.12 and 76.64), b* (+ yellow - blue, 10.69 and -4.14) and hue angle (17.1 and -8.58) maximum value. Apart from these variations, mutants of Rosa gruss an teplitz also produced variegated, pink color and different shape flowers. Genetic variations observed among the putative mutants of Rosa gruss an teplitz and Rosa centifolia were evaluated using twelve decamer RAPD primers. Phylogenetic inferences showed large genetic diversity in putative mutants as compared to mother plant. (author)

  13. Prospects of induced mutations and biotechnology in vegetatively propagated crop improvement

    International Nuclear Information System (INIS)

    Nuclear applications in food and agriculture have contributed greatly in enhancing agriculture production of seed and vegetatively propagated crops. As the human population grows continuously and climate changes furthermore, plant breeders are under pressure to adopt new technologies in genetic improvement of vegetative propagated crops for sustainable production. Plant tissue culture has a great potential in plant improvement, provided plants can be readily regenerated in large numbers. It provides the options to reduce costs in generating the useful traits and pre-breeding materials for plant breeders, as well as shortening the screening program. In vitro culture techniques together with nuclear technology is effective in generating genetic variability, selection of useful mutants and their multiplication in large numbers, especially in vegetative propagated crops. Shoot tips can be irradiated with an optimal radiation dose, induce direct shoot formation, and shoot multiplication. Excise individual shoots and put them for rooting and rooted plantlets are hardened in the greenhouse for further evaluations. Radiation treatment of somatic embryogenic cell suspension cultures is suitable for mutation induction, mutant selection, and plant regeneration. For example, bayoud disease resistant date palm mutant plants have been regenerated, which are already in the field. In banana, black sigatoka disease resistant mutant lines are in field trials for the final confirmation of the selected mutants before releasing to the farmers. A wide range of mutants of several ornamental plants including chrysanthemum, roses, orchids, gerbera, and curcuma have been isolated by physical mutagen treatment. Some of the selected traits of the mutant ornamental plants are flower colour, flower morphology, plant architecture, compact growth, flower type, and variegated leaves; many flower mutant varieties have been released to growers. (author)

  14. M 127- A Promising Tomato Variety Developed Through Induced Mutation Technique

    International Nuclear Information System (INIS)

    Bacterial wilt (BW) is the most serious constraints for tomato cultivation in Sri Lanka. At present, the producers and consumers are more interested in yield and quality of produce. The objective of this study was to develop genotypes having BW resistance, high yield potential (>20 t/ha) with desirable fruit qualities. Application of induced mutations was practiced on the Manik variety. It is a well-adapted variety with BW resistance, large fruit size with low fruit weight (76 g) due to large empty locular cavities. Several beneficial mutants better than the parent variety were identified in the M2 generation and confirmed in the M4 generation. The five most promising mutants were evaluated for BW resistance, fruit quality and yield. During dry and wet seasons, the yield evaluation studies were conducted in research and farmers' fields. The mutant M 127 gave significantly higher yields (32.2 t/ha) than the check variety T 245 (21.7 t/ha) during the both seasons. Bacterial wilt screening in the field and laboratory demonstrated that M 127 was moderately resistant. The National Coordinated Varietal Trials confirmed that it was a promising mutant under different agro-ecological zones in both dry and wet seasons. Farm trials indicated that farmer acceptability was higher for the mutant than the check variety. The mutant M 127 possesses high fruit weight (158.6 g), red, slightly flattened firm fruits. It is highly acceptable for table purposes. In the near future the mutant M 127 will be officially released to farmers and at present, it is utilized as a donor parent in the development of new HF3 hybrid under the heterosis breeding programme. (author)

  15. Aminoglycoside-induced mutation suppression (stop codon readthrough) as a therapeutic strategy for Duchenne muscular dystrophy

    OpenAIRE

    Malik, Vinod; Rodino-Klapac, Louise R.; Viollet, Laurence; Mendell, Jerry R.

    2010-01-01

    Duchenne muscular dystrophy (DMD) is the most common, lethal, X-linked genetic disease, affecting 1 in 3500 newborn males. It is caused by mutations in the DMD gene. Owing to the large size of the gene, the mutation rate in both germline and somatic cells is very high. Nearly 13–15% of DMD cases are caused by nonsense mutations leading to premature termination codons in the reading frame that results in truncated dystrophin protein. Currently there is no cure for DMD. The only available treat...

  16. X-rays induce more mutations at the tk locus than at the hgprt locus in human lymphoblastoid cells

    International Nuclear Information System (INIS)

    In rodent cell systems, it has previously been noted that higher levels of gene-locus mutations are induced at autosomal loci than at X-linked loci. Generally, this has been attributed to the likelihood that the presence of alleles of essential genes on the homologous autosome permits large-scale alterations (deletion, recombination, gene conversion, etc.) in the chromosome which contains the + allele of the selectable marker, without deleterious effects to the cell. The authors found a similar result in human lymphoblastoid cells. X-rays induced two classes of mutants at the autosomal tk locus. These were differentiated by their growth rates. Both classes were induced by x-rays with linear kinetics as a function of dose; however, about 4-5 times as many slow-growing mutants appeared. Only mutants with normal growth rates were observed at the X-linked hgprt locus; the level of induced mutation was equal to the fraction of normally-growing tk mutants. They interestingly, found that ethylmethanesulfonate (EMS) also induced both classes of mutants at the tk locus, although only about 1/3 of the total were of the slow-growing variety. Molecular characterizations of a large number of these mutants have been performed and the data are presented in the paper

  17. Somatic-cell mutation induced by short exposures to cigarette smoke in urate-null, oxidative stress-sensitive Drosophila.

    Science.gov (United States)

    Uchiyama, Tomoyo; Koike, Ryota; Yuma, Yoko; Okamoto, Keinosuke; Arimoto-Kobayashi, Sakae; Suzuki, Toshinori; Negishi, Tomoe

    2016-01-01

    We previously reported that a urate-null strain of Drosophila is hypersensitive to cigarette smoke (CS), and we suggested that CS induces oxidative stress in Drosophila because uric acid is a potent antioxidant. Although the carcinogenic risk of CS exposure is widely recognized; documentation of in vivo genotoxic activity of environmental CS, especially gaseous-phase CS, remains inconclusive. To date, somatic-cell mutations in Drosophila resulting from exposure to CS have not been detected via the somatic mutation and recombination test (wing spot test) with wild-type flies, a widely used Drosophila assay for the detection of somatic-cell mutation; moreover, genotoxicity has not been documented via a DNA repair test that involves DNA repair-deficient Drosophila. In this study, we used a new Drosophila strain (y v ma-l; mwh) to examine the mutagenicity induced by gaseous-phase CS; these flies are urate-null due to a mutation in ma-l, and they are heterozygous for multiple wing hair (mwh), a mutation that functions as a marker for somatic-cell mutation. In an assay with this newly developed strain, a superoxide anion-producing weed-killer, paraquat, exhibited significant mutagenicity; in contrast, paraquat was hardly mutagenic with a wild-type strain. Drosophila larvae were exposed to CS for 2, 4 or 6h, and then kept at 25°C on instant medium until adulthood. After eclosion, mutant spots, which consisted of mutant hairs on wings, were scored. The number of mutant spots increased significantly in an exposure time-dependent manner in the urate-null females (ma-l (-/-)), but not in the urate-positive females (ma-l (+/-)). In this study, we showed that short-term exposure to CS was mutagenic in this in vivo system. In addition, we obtained suggestive data regarding reactive oxygen species production in larva after CS exposure using the fluorescence probe H2DCFDA. These results suggest that oxidative damage, which might be countered by uric acid, was partly responsible

  18. Long-term exposure to a magnetic field (5 mT at 60 Hz) increases X-ray-induced mutations

    International Nuclear Information System (INIS)

    Exposure to extremely low frequency magnetic field (ELFMF) at 400 mT has been shown to induce mutations (Mutat. Res., 349: 109-114, 1996; Int. J. Radiat. Biol., 71: 75-79, 1997; and Biochem. Biophys. Res. Commun., 243: 579-584, 1998). However, whether ELFMF at low flux densities (under 1 mT) induces mutations is debatable. We investigated the effect of long-term exposure to 5 mT ELFMF at 60 Hz on mutant frequency. Chinese hamster ovary K1 (CHO-K1) cells were exposed or sham-exposed to 5 mT ELFMF for up to 6 weeks with or without X-irradiation (3 Gy), and the mutant frequency of the hypoxanthine-guanine phosphoribosyl transferase (HPRT) gene was analyzed. Long-term exposure to 5 mT ELFMF did not increase mutations, suggesting a threshold for mutation induction greater than 115 mA/m2 or a magnetic density of 5 mT. However, enhancement of the X-ray-induced mutation rate was observed after treatment with X-irradiation followed by long-term exposure to 5 mT ELFMF. At little as a 1-week exposure to ELFMF after X-irradiation enhanced the mutation rate. We also found that 400 mT exposure enhanced the mutation rate induced by X-irradiation (Mutat. Res., 349: 109-114, 1996). These results suggest that exposure to more than 5 mT ELFMF may promote X-ray-induced mutations. (author)

  19. Herpesvirus Telomerase RNA (vTR) with a Mutated Template Sequence Abrogates Herpesvirus-Induced Lymphomagenesis

    OpenAIRE

    Kaufer, Benedikt B; Sina Arndt; Sascha Trapp; Nikolaus Osterrieder; Jarosinski, Keith W.

    2011-01-01

    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)...

  20. Somaclonal variation and comparison to mutation induced by X-rays in rice (Oryza sativa L.) by using rice landmarker

    International Nuclear Information System (INIS)

    By using rice DNA clones of landmarker set 1, set 2 and new set, RFLP analysis was carried out in plants of cv. Tsugaruotome and cv. Mutsuhomare which were derived from 300 Gy of X-ray-irradiated seeds. In the three landmarker sets were consisted of 106 genomic DNA clones and 235 cDNA clones. Each cultivar has five plants which showed polymorphism. It is considered that the occurrence of some mutation of gene concerned with DNA repairing because certain plants showed polymorphism by many landmarkers as probes. Activity of retrotransposon such as Tos17 and alteration of methylation pattern were not observed on any plants derived from X-ray-irradiated seeds. On the other hand, in plants regenerated from cultured calli, it was found the movement of Tos17 to certain area of hot spot and alteration of methylation pattern. Furthermore, it has been reported that amplification of repeated DNA segment which was not observed in the mutation induced by X-rays. Thus, on plant breeding the somaclonal variation may be more useful than the mutation induced by X-rays

  1. Protective effect of curcumin and chlorophyllin against DNA mutation induced by cyclophosphamide or benzo[a]pyrene

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, M.A.; Elbehairy, A.M.; Ghoneim, M.A.; Amer, H.A. [Cairo Univ., Giza (Egypt). Biochemistry Dept. and Biotechnology Center

    2007-03-15

    The current study was carried out to evaluate the potency of curcumin and chlorophyllin as natural antioxidants to reduce the oxidative stress markers induced by cyclophosphamide (CP) and benzo[a]pyrene [B(a)P] which were used as free radical inducers. For this purpose, 126 male albino rats were used. The animals were assigned into 4 main groups: negative control group; oxidant-treated group (subdivided into two subgroups: cyclophosphamide- treated group and benzo[a]pyrene-treated group); curcumin-treated group; and chlorophyllin-treated group. Liver samples were collected after two days post the oxidant inoculation and at the end of the experimental period (10 weeks). These samples were examined for determination of liver microsomal malondialdehyde (MDA), DNA fragmentation, restriction fragment length polymorphism (RFLP) and 8-hydroxy deoxyguanosine (8-OHdG) concentration. Both CP and B(a)P caused increments in DNA fragmentation percentages, liver microsomal MDA, concentration of 8-OHdG and induced point mutation. Treatment of rats with either curcumin or chlorophyllin revealed lower DNA fragmentation percentages, liver microsomal MDA concentration, concentration of 8-OHdG and prevented induction of mutations, i. e., reversed the oxidative stress induced by CP and B(a)P and proved that they were capable of protecting rats against the oxidative damage evoked by these oxidants. (orig.)

  2. Gamma ray, EMS and sodium azide induced effectiveness and efficiency of chlorophyll mutations in basmati rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    The effectiveness and efficiency of gamma ray, EMS, sodium azide alone or in combination in relation to chlorophyll mutations in two varieties of Basmati rice (Oryza sativa L.) in M2 generation were studied. The chlorophyll mutations were induced by all the doses of mutagens alone or in combination relatively at a fair frequency in both the varieties in M2 generation. In general, it was found that combination treatments of gamma rays and EMS were observed to be more efficient in Taraori Basmati, while EMS alone and combination treatment of gamma rays and EMS were more efficient in Pusa Basmati 1 on sterility and growth injury basis both. Sodium azide at 0.5 mM was found as the most effective dose in both Taraori Basmati and Pusa Basmati 1 cultivars. (author)

  3. Development of Sorghum Tolerant to Acid Soil Using Induced Mutation with Gamma Irradiation

    Directory of Open Access Journals (Sweden)

    S. Human

    2010-04-01

    Full Text Available Water scarcity still becomes a problem in some dryland agricultural areas in Indonesia. Development of dryland farming system may be focused on crops that are required less water such as sorghum. Sorghum is a cereal crop that is usually grown under hot and dry condition and it is ideal for Indonesia. Sorghum is a good source of food, animal feed and raw material for ethanol. Indonesia is currently looking for alternative renewable energy resources and sorghum is regarded as one of the promising source of bioethanol as bioenergy. Unfortunately, most agricultural land in western part of the country particularly in Sumatera and Kalimantan is dryland and dominated by acid soil. The main constraint of crop production in acid soil is deficiency and Al toxicity. Therefore, development of sorghum cultivation in dryland farming system requires a variety which is tolerant to such conditions. Sorghum breeding for acid soil tolerance had been conducted at PATIR-BATAN by using induced mutations with gamma irradiation. The breeding objective was to search for sorghum genotypes tolerant to acid soil condition and with regard to sorghum use for bioethanol production. A number of 66 breeding materials, including the mutants, had been screened for acid soil tolerance on land with soil pH of 4.2 and 39% Al saturation in Lampung Province. Ten sorghum genotypes had been identified as high yielding in the acid soil condition. The mutant lines GH-ZB-41-07, YT30-39-07, B-76 and B-92 had grain yield higher (>4.5 t/ha than the control plants (Durra, Mandau and Numbu. Sorghum mutants ZH30-29-07, ZH30-30-07 and ZH30-35-07 were promising for grain-base bioethanol production with ethanol yield exceeded 2,000 l/ha. Meanwhile, the sweet sorghum mutants ZH30-35-07, ZH30-30-07 and ZH30-29-07 had brix content of 11.59, 11.95 and 10.50%, respectively. These mutant lines are promising to be developed further in sorghum breeding since they are highly tolerant to acid soils.

  4. Development Of Sorghum Tolerant To Acid Soil Using Induced Mutation With Gamma Irradiation

    International Nuclear Information System (INIS)

    Water scarcity still becomes a problem in some dry land agricultural areas in indonesia. Development of dry land farming system may be focused on crops that are required less water such sorghum. Sorghum is a cereal crop that is usually grown under hot and dry condition and it is ideal for Indonesia. Sorghum is good source of food, animal feed and raw material for ethanol. Indonesia is currently looking for alternative renewable energy resources and sorghum is regarded as one of the promising source of bio ethanol as bio energy. Unfortunately, most agricultural land in western part of the country particularly in Sumatera and Kalimantan is dry land and dominated by acid soil. The main constrain of crop production in acid soil is a deficiency and Al toxic. Therefore, development of sorghum cultivation in dry land farming system requires a variety which is tolerant to such conditions. Sorghum breeding for acid soil tolerance had been conducted at PATIR-BATAN by using induced mutations with gamma irradiation. The breeding objective was search for sorghum genotype tolerant to acid soil condition and regard to sorghum use for bio ethanol production. A number of 66 breeding materials, including the mutants, had been screened for acid soil tolerance on land with soil pH of 4.2 and 39 % Al saturation in Lampung Province. Ten sorghum genotypes had been identified as high yielding in the acid soil condition. the mutant lines GHZB41-07, YT30-39-07, B-76 and B-29 had grain yield higher(>4.5 t/ha) than the control plants (Durra, Mandau and Numbu). Sorghum mutants ZH30-29-07, ZH30-30-07 and ZH30-35-07 were promising for grain base bio etahnol production with ethanol yield exceeded 2,000 l/ha. Meanwhile, the sweet sorghum mutants ZH30-35-07, ZH30-29-07 had brix content of 11.59, 11.95 and 10.50%, respectively. These mutant lines are promising to be developed further in sorghum breeding since they are highly tolerant to acid soils. (author)

  5. Induced mutation breeding for resistance to yellow vein mosaic virus in okra

    International Nuclear Information System (INIS)

    Seeds of Annie and Okura okra varieties were irradiated by gamma rays to induce mutations for resistance to yellow vein mosaic virus disease (YVMD). In experiment I, seeds were irradiated at 400, 600 and 800 Gy and then planted at Huaysai King's Project, Petchaburi Province. Plants with a good plant type and green pods were selected for M2 generation. M3 plants were grown at Phichit Horticultural Research Center (PHRC) where YVMD was seriously widespread. 33 plants without disease symptoms were selected for further screening. By using white fly transmission under greenhouse conditions, only four lines showed no disease symptoms. They were transplanted to the field at PHRC. Only Okura irradiated at 400 Gy, designated Rd53-3 showed disease resistance. Subsequent selections were conducted under greenhouse and field conditions up to M7 generation. Twelve resistant lines showing uniformity of plant type were selected for yield trial observation. All bore reasonable yield but their fruit shape was not suitable for the export market. They will be used as parental lines in further breeding programs. In experiment II, seeds of Annie and Okura were irradiated at doses of 400 and 600 Gy and then planted at Huaysai. M2 seeds were collected by two methods, the pedigree method by collecting seeds from selected healthy plants, and then planted them at Huaysai. The other method was bulk selection and then seeds were planted at Huaysai and PHRC. The M3 generation was screened for disease resistance under greenhouse and field conditions. The plants from bulk selection were all infected. By pedigree selection, 34 and 35 lines of Annie and Okura, respectively were obtained. Screening for okra YVMD resistance under greenhouse and field conditions in M4 generation, it was found that only one plant of Okura irradiated at 400 Gy designated B-21, showed no disease symptoms. Disease resistance screenings under greenhouse and field conditions were performed during M5 to M7 generation. Ten

  6. Improvement of rapeseed and mustard by induced mutations and in vitro techniques

    International Nuclear Information System (INIS)

    Research on the improvement of rapeseed (Brassica napus L.) and mustard (Brassica juncea Czern and Coss.) was initiated during 1995-96 with the objective to develop genotypes with high yield potential, high oil content, canola quality and improved polyenoic fatty acid composition or high erucic acid for industrial applications, and tolerance to different stresses. The results of the M1 and M2 generations have been reported in the second RCM at Giessen, Germany. Stable mutants (M5) of a photo period sensitivity exotic juncea genotype (DLJ-3) were assessed in preliminary yield trials (PYT) in the field for yield and other agronomic characteristics in comparison with the parent (P) variety. The mutants performing better in PYTs were further assessed in advanced yield trials (AYT) in comparison with P and a local commercial cultivar (LC). Fatty acid composition of promising mutants and interspecific hybrid lines was analysed by gas chromatography (GC) and total seed glucosinolates by spectrophotometry. The quality analyses showed that 50 mutants had low erucic acid contents and 10 of them showed 0%. Two mutants were isolated for high oleic acid (∼50%), 16 mutant plants had more than 35% linoleic acid and one mutant had the desirable low linolenic acid content, 3%. No mutant with more than 60% erucic acid for industrial uses was found. The yield tests indicated that significant variability existed among the mutant lines with regards to different traits. 58 mutants flowered significantly earlier, reducing their growing period by 17 to 55% as compared to P (control), 43 were significantly shorter than P (7-30% reduction in height), and 32 mutants out yielded the parent line significantly by a margin of 26-71% during two years of field testing. Some of the mutants exhibited better performance than P and LC under local short photo period environment, indicating adaptability and great potential to replace the indigenous non-canola genotypes. Induced mutations appear to

  7. Mutations in uvrD induce the SOS response in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Ossanna, N.; Mount, D.W.

    1989-01-01

    We have isolated three new mutations in uvrD that increase expression of the Escherichia coli SOS response in the absence of DNA damage. Like other uvrD (DNA helicase II) mutants, these strains are sensitive to UV irradiation and have high spontaneous mutation frequencies. Complementation studies with uvrD+ showed that UV sensitivity and spontaneous mutator activity were recessive in these new mutants. The SOS-induction phenotype, however, was not completely complemented, which indicated that the mutant proteins were functioning in some capacity. The viability of one of the mutants in combination with rep-5 suggests that the protein is functional in DNA replication. We suggest that these mutant proteins are deficient in DNA repair activities (since UV sensitivity is complemented) but are able to participate in DNA replication. We believe that defective DNA replication in these mutants increases SOS expression.

  8. Mutations in uvrD induce the SOS response in Escherichia coli

    International Nuclear Information System (INIS)

    We have isolated three new mutations in uvrD that increase expression of the Escherichia coli SOS response in the absence of DNA damage. Like other uvrD (DNA helicase II) mutants, these strains are sensitive to UV irradiation and have high spontaneous mutation frequencies. Complementation studies with uvrD+ showed that UV sensitivity and spontaneous mutator activity were recessive in these new mutants. The SOS-induction phenotype, however, was not completely complemented, which indicated that the mutant proteins were functioning in some capacity. The viability of one of the mutants in combination with rep-5 suggests that the protein is functional in DNA replication. We suggest that these mutant proteins are deficient in DNA repair activities (since UV sensitivity is complemented) but are able to participate in DNA replication. We believe that defective DNA replication in these mutants increases SOS expression

  9. Low-energy (30 keV) carbon ion induced mutation spectrum in the LacZα gene of M13mp18 double-stranded DNA

    International Nuclear Information System (INIS)

    Double-stranded M13mp18 DNA was irradiated with 30 keV carbon ions in dry state under vacuum to investigate the low-energy heavy ion induced mutation spectra. When the irradiated DNA was used to transfect Escherichia coli JM105, 3.6-5.7-fold increases in mutation frequency were observed, in contrast to the spontaneous group. Sequences of the 92 induced mutants showed that the carbon ions in this study could induce an interesting mutation spectrum in the lacZα gene. One-base mutations (96.8%) and base pair substitutions (56.4%) were predominant, most of which involved G:C base pairs (90.6%), especially G:C → T:A transversions (49.6%) and G:C → A:T transitions (39.6%). This is similar to the spectra induced by γ-rays in the same ds M13, wild type E. coli system. We also found a considerable amount of carbon ion induced one-base deletion (38.5%) and the mutation sites distribution on the target lacZα gene was obviously non-random. We compared this study with previous data employing γ-rays to discuss the possible causes of the mutation spectrum

  10. Mutations of winter wheat induced by radionuclide contamination resulted from Chernobyl catastrophe

    International Nuclear Information System (INIS)

    It is shown that a high level of radionuclide contamination has been retained until 1992 in the zone of Chernobyl catastrophe (village Chistogalovka and the town of Pripyat).This causes the increase of the frequency of chromosome aberrations and visible mutations within the winter wheat (2.49 to 6.39 times) and (2.6 to 13.0 times), correspondingly. Chromosome aberrations and visible mutations which effect qualitative and quantitative characteristics, revealed over a long period of time, indicate that the retaining level of radionuclide contamination continues to be an efficient mutagen factor of the environment

  11. Synergy between Apc min and an activated ras mutation is sufficient to induce colon carcinomas.

    OpenAIRE

    D Abaco, G. M.; Whitehead, R. H.; Burgess, A W

    1996-01-01

    Colon carcinomas appear to arise from the cumulative effect of mutations to several genes (APC, DCC, p53, ras, hMLH1, and hMSH2). By using novel colonic epithelial cell lines derived from the Immorto mouse, named the YAMC (young adult mouse colon) cell line, and an Immorto-Min mouse hybrid, named the IMCE (Immorto-Min colonic epithelial) cell line, carrying the Apc min mutation, we investigated the effect of an activated v-Ha-ras gene on tumor progression. The YAMC and IMCE cell lines are nor...

  12. Specific UV-induced mutation spectrum in the p53 gene of skin tumors from DNA-repair-deficient xeroderma pigmentosum patients

    International Nuclear Information System (INIS)

    The UV component of sunlight is the major carcinogen involved in the etiology of skin cancers. The authors have studied the rare, hereditary syndrome xeroderma pigmentosum (XP), which is characterized by a very high incidence of cutaneous tumors on exposed skin at an early age, probably due to a deficiency in excision repair of UV-induced lesions. It is interesting to determine the UV mutation spectrum in XP skin tumors in order to correlate the absence of repair of specific DNA lesions and the initiation of skin tumors. The p53 gene is frequently mutated in human cancers and represents a good target for studying mutation spectra since there are >100 potential sites for phenotypic mutations. Using reverse transcription-PCR and single-strand conformation polymorphism to analyze >40 XP skin tumors (mainly basal and squamous cell carcinomas), the authors have found that 40% (17 out of 43) contained at least one point mutation on the p53 gene. All the mutations were located at dipyrimidine sites, essentially at CC sequences, which are hot spots for UV-induced DNA lesions. Sixty-one percent of these mutations were tandem CC → TT mutations considered to be unique to UV-induced lesions; these mutations are not observed in internal human tumors. All the mutations, except two, must be due to translesion synthesis of unrepaired dipyrimidine lesions left on the nontranscribed strand. These results show the existence of preferential repair of UV lesions [either pyrimidine dimers or pyrimidine-pyrimidone (6-4) photoproducts] on the transcribed strand in human tissues

  13. Role of combined use of classical induced mutation breeding and biotechnology in development of new flower colour/form in ornamentals

    International Nuclear Information System (INIS)

    In floriculture trade there is always demand and necessity of new and novel ornamental varieties. Flower colour is one of the most important component of novelties. Induced somatic mutation techniques by using ionizing radiations and other mutagens have successfully produced quite a large number of new promising varieties (50 Nos.) in different ornamental (Bougainvillea, Chrysanthemum, Hibiscus, Rose, Tuberose, Lantana depressa etc.) plants by bringing about genetic changes at Floriculture Section, National Botanical Research Institute, India. For inducing novelties in flower colour of different plants the technique of selection of proper type/state of plant material for experiment, suitable dose, detection of mutation at right stage of development, isolation and multiplication of chimeric tissue have been standardised. The capability of the technique is well understood from significant number of new varieties developed via direct mutation breeding in already adapted, modern genotypes and enriched the germplasm. The mutations in flower lour/shape were detected as chimera in M1v1, M1v2, M1v3 generations. The mutation frequency varied with the cultivar and exposure of gamma rays. The main bottleneck of mutation breeding is that the mutation appears as chimera. When the entire branch is mutated, mutants can be isolated through conventional propagation techniques while small sectorial mutation in the floret cannot be isolated using existing conventional techniques. Therefore, many new flower colour/shape mutants are lost due to the lack of a suitable propagation technique. By applying biotechnological technique on the same mutagen treated gamma rays population a novel tissue culture technique hasbeen standardised to regenerate plants directly from such mutated sectors (ray florets) of Chrysanthemum. A number of somatic flower colour/shape mutants have been developed in Chrysanthemum by using this in vitro technique. Combination of classical mutation breeding and

  14. BRD4-targeted therapy induces Myc-independent cytotoxicity in Gnaq/11-mutatant uveal melanoma cells.

    Science.gov (United States)

    Ambrosini, Grazia; Sawle, Ashley D; Musi, Elgilda; Schwartz, Gary K

    2015-10-20

    Uveal melanoma (UM) is an aggressive intraocular malignancy with limited therapeutic options. Both primary and metastatic UM are characterized by oncogenic mutations in the G-protein alpha subunit q and 11. Furthermore, nearly 40% of UM has amplification of the chromosomal arm 8q and monosomy of chromosome 3, with consequent anomalies of MYC copy number. Chromatin regulators have become attractive targets for cancer therapy. In particular, the bromodomain and extra-terminal (BET) inhibitor JQ1 has shown selective inhibition of c-Myc expression with antiproliferative activity in hematopoietic and solid tumors. Here we provide evidence that JQ1 had cytotoxic activity in UM cell lines carrying Gnaq/11 mutations, while in cells without the mutations had little effects. Using microarray analysis, we identified a large subset of genes modulated by JQ1 involved in the regulation of cell cycle, apoptosis and DNA repair. Further analysis of selected genes determined that the concomitant silencing of Bcl-xL and Rad51 represented the minimal requirement to mimic the apoptotic effects of JQ1 in the mutant cells, independently of c-Myc. In addition, administration of JQ1 to mouse xenograft models of Gnaq-mutant UM resulted in significant inhibition of tumor growth.Collectively, our results define BRD4 targeting as a novel therapeutic intervention against UM with Gnaq/Gna11 mutations. PMID:26397223

  15. A sucrose-rich diet induces mutations in the rat colon

    DEFF Research Database (Denmark)

    Dragsted, Lars O.; Daneshvar, Bahram; Vogel, Ulla;

    2002-01-01

    sucrose-rich diet. No significant increase in mutations was observed in the liver. To seek an explanation for this finding, a variety of parameters were examined representing different mechanisms, including increased oxidative stress, changes in oxidative defense, effects on DNA repair, or changes in the...

  16. Gamma rays induced bract colour mutation in single bracted bougainvillea 'Palekar'

    International Nuclear Information System (INIS)

    Bougainvillea (Nyctaginaceae) is a hardy perennial climbing ornamental plant. It is in good demand in floriculture and landscaping specially in the tropical and sub-tropical regions. Bougainvillea Palekar a floriferous cultivar with attractive bracts, was included in the mutation breeding programme for genetic improvement

  17. An assessment of gamma ray induced mutations in rice (Oryza sativa l.)

    International Nuclear Information System (INIS)

    Gamma ray seed treatment (10, 20 and 30 kR doses) of two cultivars, namely, MPRI-7 and Lanjhi was found to affect pollen and spikelet fertility in M1 generation at higher dose. Chlorophyll and morphological mutations having wider spectrum were also obsrved in M2 generation

  18. Studies on radiation induced mutation of pollen, ovary and plant of wheat

    International Nuclear Information System (INIS)

    The pollen, ovary and whole plants of wheat in spike forming stage, ear sprouting stage and the end of flowering stage were irradiated by 60Co γ-rays. The seed setting rate in the treated generation were calculated. The survival rate of M1 plants, the mutation rate and the mutant types in M2 were investigated. The results show that the optimal dose for irradiation of wheat living plants is 0.206 to 0.516 C/kg(800∼2000 R) that is only one tenth for irradiation of dry wheat seeds, and the whole mutation rate, beneficial mutation frequency and percentage of beneficial mutation for irradiation of living plants are 50 ∼57%,, 22∼24% and 83∼127% higher than that for irradiation of dry seeds, respectively. The results also show that in the same exposure range the smaller exposure rate has more effects. The optimal exposure rate is 7.74∼12.9 mC/kg (30∼50 R) per minute

  19. How does the 'ancient' asexual Philodina roseola (Rotifera : Bdelloidea) handle potential UVB-induced mutations?

    NARCIS (Netherlands)

    Fischer, Claus; Ahlrichs, Wilko H.; Buma, Anita G. J.; van de Poll, Willem H.; Bininda-Emonds, Olaf R. P.

    2013-01-01

    Like other obligate asexuals, bdelloid rotifers are expected to suffer from degradation of their genomes through processes including the accumulation of deleterious mutations. However, sequence-based analyses in this regard remain inconclusive. Instead of looking for historical footprints of mutatio

  20. Opening Remarks by W Burkart [International Symposium on Induced Mutations in Plants, Vienna (Austria), 12-15 August 2008

    International Nuclear Information System (INIS)

    This international Symposium, promoted by the Joint FAO/IAEA Division, is the eighth of its kind - the first was held in 1969 - dedicated to harnessing and disseminating information on current trends in induced mutagenesis in plants. These symposia have 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. The Joint FAO/IAEA Division has been promoting the efficient use of mutation techniques since the late 1960's, in line with the Agency's 'atoms for peace' agenda, very much related to agricultural policy and practices of some our main donor nations. In 1960, for example, in the United States, disease heavily damaged the bean crop in Michigan - except for a promising new variety that had been made by radiation breeding, which quickly replaced the old bean. The Manual on Mutation Breeding, edited by the Agency and first published in 1970, updated in 1979 and reprinted several times afterwards, was the first book of its kind in the world. It has been widely used both as textbook in universities (translated into a couple of local languages) and reference book for breeders in their profession. Together with the training provided to scientists in developing countries and the support and coordination of research activities in this area, this manual has greatly promoted the correct and efficient use of mutation techniques in crop improvement. At a time when the world is facing a food and energy crisis of unprecedented proportions, plant mutation breeding can be a catalyst in developing improved, higher-yield, saline-resistant sturdier crop varieties. More and more, the interest of the scientific community in this discipline has focused on the discovery of genes that control important traits, and on understanding the functions and

  1. Proteomic analysis of the low mutation rate of diploid male gametes induced by colchicine in Ginkgo biloba L.

    Directory of Open Access Journals (Sweden)

    Nina Yang

    Full Text Available Colchicine treatment of G. biloba microsporocytes results in a low mutation rate in the diploid (2n male gamete. The mutation rate is significantly lower as compared to other tree species and impedes the breeding of new economic varieties. Proteomic analysis was done to identify the proteins that influence the process of 2n gamete formation in G. biloba. The microsporangia of G. biloba were treated with colchicine solution for 48 h and the proteins were analyzed using 2-D gel electrophoresis and compared to protein profiles of untreated microsporangia. A total of 66 proteins showed difference in expression levels. Twenty-seven of these proteins were identified by mass spectrometry. Among the 27 proteins, 14 were found to be up-regulated and the rest 13 were down-regulated. The identified proteins belonged to five different functional classes: ATP generation, transport and carbohydrate metabolism; protein metabolism; ROS scavenging and detoxifying enzymes; cell wall remodeling and metabolism; transcription, cell cycle and signal transduction. The identification of these differentially expressed proteins and their function could help in analysing the mechanism of lower mutation rate of diploid male gamete when the microsporangium of G. biloba was induced by colchicine.

  2. Sesame improvement by induced mutations: Results of the co-ordinated research project and recommendation for future studies

    International Nuclear Information System (INIS)

    The FAO/IAEA Co-ordinated Research Project has brought together sesame breeders from 11 countries. They, together with pathologists, agronomists and physiologists, have made considerable effort to advance the genetic improvement in sesame. The results and conclusions from this project cover the mutation techniques used for the genetic improvement of various aspects of sesame. These recommendations do not only deal with the application of mutation induction, but also with the wider plant breeding related objectives and methods to be considered for this semi-domesticated crop. It is clear that more advanced techniques can and should be incorporated in the process which would enhance the genetic improvement. Although five years is a relatively limited time in a plant breeding programme, the participants have been able to produce and make available a considerable pool of agronomically interesting mutant sesame germplasm. The participants in the CRP considered that, together with other specialists, plant breeders can gain fuller benefit from the mutations induced by radiation or chemicals. Work on these mutants must continue in co-operation/consultation with plant physiologists and pathologists, and with biotechnologists who may in the future be able to provide in the future methods for introducing beneficial traits from other crops into sesame. The sesame programme should include scientists from the Member States where sesame grows and scientists from developed countries who may have greater access to physiological and molecular research facilities. (author)

  3. Antimutagenic effect of Phellinus rimosus (Berk) Pilat against chemical induced mutations of histidine dependent Salmonella typhimurium strains.

    Science.gov (United States)

    Ajith, T A; Janardhanan, K K

    2011-10-01

    Mutations are one of the important factors contributing to oncogenesis. Somatic mutations have been detected in oncogenes and tumor suppressor genes in various types of cancers. In vitro antimutagenic activity of ethyl acetate extract of macro fungus, Phellinus rimosus was evaluated by Ames' mutagenicity assay. The effect was evaluated against the direct acting mutagens (sodium azide, N-methyl-N'-nitro-N-nitrosoguanidine, doxorubicin and 4-nitro-o-phenylenediamine) and mutagen needing activation (2-acetyl aminofluorine, and benzo[a]pyrene). The extract was significantly (p<0.05) and dose dependently effective against direct acting mutagens and mutagen needing activation. Among the antimutagenic activity against directly acting mutagens, effect was found to be highest against doxorubicin-induced mutation. The antimutagenic effect of the extract against indirect acting mutagen in the presence of mammalian metabolic activation system was also found to be significant (p<0.01). The background bacterial growth and number of revertant colonies in the extract alone treated plate with or with out metabolic activator was almost same as that of spontaneous revertants. This indicated the non-toxic nature of the extract. The effect was partially ascribed to the antioxidant activity. The results of the study suggest the possible antitumor mechanisms of P. rimosus. PMID:21784121

  4. Proteomic analysis of the low mutation rate of diploid male gametes induced by colchicine in Ginkgo biloba L.

    Science.gov (United States)

    Yang, Nina; Sun, Yuhan; Wang, Yaru; Long, Cui; Li, Yingyue; Li, Yun

    2013-01-01

    Colchicine treatment of G. biloba microsporocytes results in a low mutation rate in the diploid (2n) male gamete. The mutation rate is significantly lower as compared to other tree species and impedes the breeding of new economic varieties. Proteomic analysis was done to identify the proteins that influence the process of 2n gamete formation in G. biloba. The microsporangia of G. biloba were treated with colchicine solution for 48 h and the proteins were analyzed using 2-D gel electrophoresis and compared to protein profiles of untreated microsporangia. A total of 66 proteins showed difference in expression levels. Twenty-seven of these proteins were identified by mass spectrometry. Among the 27 proteins, 14 were found to be up-regulated and the rest 13 were down-regulated. The identified proteins belonged to five different functional classes: ATP generation, transport and carbohydrate metabolism; protein metabolism; ROS scavenging and detoxifying enzymes; cell wall remodeling and metabolism; transcription, cell cycle and signal transduction. The identification of these differentially expressed proteins and their function could help in analysing the mechanism of lower mutation rate of diploid male gamete when the microsporangium of G. biloba was induced by colchicine. PMID:24167543

  5. Mutation induced extinction in finite populations: lethal mutagenesis and lethal isolation.

    Science.gov (United States)

    Wylie, C Scott; Shakhnovich, Eugene I

    2012-01-01

    Reproduction is inherently risky, in part because genomic replication can introduce new mutations that are usually deleterious toward fitness. This risk is especially severe for organisms whose genomes replicate "semi-conservatively," e.g. viruses and bacteria, where no master copy of the genome is preserved. Lethal mutagenesis refers to extinction of populations due to an unbearably high mutation rate (U), and is important both theoretically and clinically, where drugs can extinguish pathogens by increasing their mutation rate. Previous theoretical models of lethal mutagenesis assume infinite population size (N). However, in addition to high U, small N can accelerate extinction by strengthening genetic drift and relaxing selection. Here, we examine how the time until extinction depends jointly on N and U. We first analytically compute the mean time until extinction (τ) in a simplistic model where all mutations are either lethal or neutral. The solution motivates the definition of two distinct regimes: a survival phase and an extinction phase, which differ dramatically in both how τ scales with N and in the coefficient of variation in time until extinction. Next, we perform stochastic population-genetics simulations on a realistic fitness landscape that both (i) features an epistatic distribution of fitness effects that agrees with experimental data on viruses and (ii) is based on the biophysics of protein folding. More specifically, we assume that mutations inflict fitness penalties proportional to the extent that they unfold proteins. We find that decreasing N can cause phase transition-like behavior from survival to extinction, which motivates the concept of "lethal isolation." Furthermore, we find that lethal mutagenesis and lethal isolation interact synergistically, which may have clinical implications for treating infections. Broadly, we conclude that stably folded proteins are only possible in ecological settings that support sufficiently large populations

  6. Mutation induced extinction in finite populations: lethal mutagenesis and lethal isolation.

    Directory of Open Access Journals (Sweden)

    C Scott Wylie

    Full Text Available Reproduction is inherently risky, in part because genomic replication can introduce new mutations that are usually deleterious toward fitness. This risk is especially severe for organisms whose genomes replicate "semi-conservatively," e.g. viruses and bacteria, where no master copy of the genome is preserved. Lethal mutagenesis refers to extinction of populations due to an unbearably high mutation rate (U, and is important both theoretically and clinically, where drugs can extinguish pathogens by increasing their mutation rate. Previous theoretical models of lethal mutagenesis assume infinite population size (N. However, in addition to high U, small N can accelerate extinction by strengthening genetic drift and relaxing selection. Here, we examine how the time until extinction depends jointly on N and U. We first analytically compute the mean time until extinction (τ in a simplistic model where all mutations are either lethal or neutral. The solution motivates the definition of two distinct regimes: a survival phase and an extinction phase, which differ dramatically in both how τ scales with N and in the coefficient of variation in time until extinction. Next, we perform stochastic population-genetics simulations on a realistic fitness landscape that both (i features an epistatic distribution of fitness effects that agrees with experimental data on viruses and (ii is based on the biophysics of protein folding. More specifically, we assume that mutations inflict fitness penalties proportional to the extent that they unfold proteins. We find that decreasing N can cause phase transition-like behavior from survival to extinction, which motivates the concept of "lethal isolation." Furthermore, we find that lethal mutagenesis and lethal isolation interact synergistically, which may have clinical implications for treating infections. Broadly, we conclude that stably folded proteins are only possible in ecological settings that support sufficiently

  7. A modified TILLING approach to detect induced mutations in tetraploid and hexaploid wheat

    Directory of Open Access Journals (Sweden)

    Tsai Helen

    2009-08-01

    Full Text Available Abstract Background Wheat (Triticum ssp. is an important food source for humans in many regions around the world. However, the ability to understand and modify gene function for crop improvement is hindered by the lack of available genomic resources. TILLING is a powerful reverse genetics approach that combines chemical mutagenesis with a high-throughput screen for mutations. Wheat is specially well-suited for TILLING due to the high mutation densities tolerated by polyploids, which allow for very efficient screens. Despite this, few TILLING populations are currently available. In addition, current TILLING screening protocols require high-throughput genotyping platforms, limiting their use. Results We developed mutant populations of pasta and common wheat and organized them for TILLING. To simplify and decrease costs, we developed a non-denaturing polyacrylamide gel set-up that uses ethidium bromide to detect fragments generated by crude celery juice extract digestion of heteroduplexes. This detection method had similar sensitivity as traditional LI-COR screens, suggesting that it represents a valid alternative. We developed genome-specific primers to circumvent the presence of multiple homoeologous copies of our target genes. Each mutant library was characterized by TILLING multiple genes, revealing high mutation densities in both the hexaploid (~1/38 kb and tetraploid (~1/51 kb populations for 50% GC targets. These mutation frequencies predict that screening 1,536 lines for an effective target region of 1.3 kb with 50% GC content will result in ~52 hexaploid and ~39 tetraploid mutant alleles. This implies a high probability of obtaining knock-out alleles (P = 0.91 for hexaploid, P = 0.84 for tetraploid, in addition to multiple missense mutations. In total, we identified over 275 novel alleles in eleven targeted gene/genome combinations in hexaploid and tetraploid wheat and have validated the presence of a subset of them in our seed stock

  8. Molecular nature of mutations induced in aging process and X-irradiation in spleen, liver and brain of LacZ-Transgenic mouse

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Tetsuya; Ikehata, Hironobu; Nakamura, Shingo; Saito, Yusuke [Tohoku Univ., Sendai (Japan). Graduate School of Medicine

    2000-07-01

    Mutation is believed to be one of the important factors in radiation-induced carcinogenesis as well as in aging. The study of mutation, however, has long been limited to cultured cells and blood cells. Thus little is known about various tissues in a body. The absence of information on molecular nature of mutations which appear in tissues makes it difficult to understand mechanisms responsible for long-term effects of radiation. The problem, however, has been overcome lately by a development of transgenic mice which are made suitable for mutation assay by introduction of E. coli gene into mouse genome. In the present study, we have used one of these transgenic mice named Muta{sup TM} and examined molecular nature of mutants accumulated in aging process and those induced by high dose of radiation. (author)

  9. Molecular nature of mutations induced in aging process and X-irradiation in spleen, liver and brain of LacZ-Transgenic mouse

    International Nuclear Information System (INIS)

    Mutation is believed to be one of the important factors in radiation-induced carcinogenesis as well as in aging. The study of mutation, however, has long been limited to cultured cells and blood cells. Thus little is known about various tissues in a body. The absence of information on molecular nature of mutations which appear in tissues makes it difficult to understand mechanisms responsible for long-term effects of radiation. The problem, however, has been overcome lately by a development of transgenic mice which are made suitable for mutation assay by introduction of E. coli gene into mouse genome. In the present study, we have used one of these transgenic mice named MutaTM and examined molecular nature of mutants accumulated in aging process and those induced by high dose of radiation. (author)

  10. Cytogenetic and genetic studies of radiation-induced chromosome damage in mouse oocytes. Part 2. Induced chromosome loss and dominant visible mutations

    International Nuclear Information System (INIS)

    The rates of X-ray induced loss of chromosome 19 in mouse oocytes were investigated in 2 experiments using a genetic complementation test. After 1 Gy of acute X-rays to immediately preovulatory stage oocytes, chromosome 19 loss was estimated to have occurred in 1.68% of cells. In comparison, after 4 Gy of acute X-rays to dictyate stage oocytes, the rate was estimated at 1.18%. The slightly higher rate of chromosome loss in the former cell stage after a smaller dose of radiation reflects the known increased radiosensitivity of mouse oocytes in the period shortly before ovulation. Comparison of the observations here for chromosome 19 with published data for chromosome 1 suggests that chromosome length is one of the principal factors in determining the initial rate of induced loss in mouse oocytes. Ten dominant visible mutations were recovered among 1674 offspring following irradiation of preovulatory oocytes, and 8 in 2025 offspring after treatment of dictyate cells. Nine dominant mutations were karyotyped, 5 of these were found to be associated with a visible chromosome rearrangement. The data obtained in the present study show that radiation-induced chromosome anomalies in female germ cells are not all filtered out by prenatal embryonic death but that a proportion has the potential to contribute to the genetic burden of the next generation

  11. Early maturation and distinct tau pathology in induced pluripotent stem cell-derived neurons from patients with MAPT mutations.

    Science.gov (United States)

    Iovino, Mariangela; Agathou, Sylvia; González-Rueda, Ana; Del Castillo Velasco-Herrera, Martin; Borroni, Barbara; Alberici, Antonella; Lynch, Timothy; O'Dowd, Sean; Geti, Imbisaat; Gaffney, Daniel; Vallier, Ludovic; Paulsen, Ole; Káradóttir, Ragnhildur Thóra; Spillantini, Maria Grazia

    2015-11-01

    Tauopathies, such as Alzheimer's disease, some cases of frontotemporal dementia, corticobasal degeneration and progressive supranuclear palsy, are characterized by aggregates of the microtubule-associated protein tau, which are linked to neuronal death and disease development and can be caused by mutations in the MAPT gene. Six tau isoforms are present in the adult human brain and they differ by the presence of 3(3R) or 4(4R) C-terminal repeats. Only the shortest 3R isoform is present in foetal brain. MAPT mutations found in human disease affect tau binding to microtubules or the 3R:4R isoform ratio by altering exon 10 splicing. We have differentiated neurons from induced pluripotent stem cells derived from fibroblasts of controls and patients with N279K and P301L MAPT mutations. Induced pluripotent stem cell-derived neurons recapitulate developmental tau expression, showing the adult brain tau isoforms after several months in culture. Both N279K and P301L neurons exhibit earlier electrophysiological maturation and altered mitochondrial transport compared to controls. Specifically, the N279K neurons show abnormally premature developmental 4R tau expression, including changes in the 3R:4R isoform ratio and AT100-hyperphosphorylated tau aggregates, while P301L neurons are characterized by contorted processes with varicosity-like structures, some containing both alpha-synuclein and 4R tau. The previously unreported faster maturation of MAPT mutant human neurons, the developmental expression of 4R tau and the morphological alterations may contribute to disease development. PMID:26220942

  12. Induced mutations for the improvement of grain legumes in South East Asia (1975)

    International Nuclear Information System (INIS)

    The report is divided into seven sections containing papers on the following subjects: regional cooperation for improving grain legume production in South-East Asia and the role of FAO in this connection; national reports on the production and consumption of grain legumes (mainly beans, soybeans, peas, peanuts) in various Asian countries (separate reports for Pakistan, India, Sri Lanka, Bangladesh, Burma, Philippines, Indonesia, Papua New Guinea, Taiwan, and Australia). Specific papers are presented on the following: modifications of field pea; chickpea breeding at ICRISAT; mutation breeding in winged bean; mutation breeding in improving groundnut cultivars; and the consumption of grain legumes in Singapore. Finally, some conclusions and recommendations adopted by the participants of the meeting are presented

  13. Myopathy-inducing mutation H40Y in ACTA1 hampers actin filament structure and function.

    Science.gov (United States)

    Chan, Chun; Fan, Jun; Messer, Andrew E; Marston, Steve B; Iwamoto, Hiroyuki; Ochala, Julien

    2016-08-01

    In humans, more than 200 missense mutations have been identified in the ACTA1 gene. The exact molecular mechanisms by which, these particular mutations become toxic and lead to muscle weakness and myopathies remain obscure. To address this, here, we performed a molecular dynamics simulation, and we used a broad range of biophysical assays to determine how the lethal and myopathy-related H40Y amino acid substitution in actin affects the structure, stability, and function of this protein. Interestingly, our results showed that H40Y severely disrupts the DNase I-binding-loop structure and actin filaments. In addition, we observed that normal and mutant actin monomers are likely to form distinctive homopolymers, with mutant filaments being very stiff, and not supporting proper myosin binding. These phenomena underlie the toxicity of H40Y and may be considered as important triggering factors for the contractile dysfunction, muscle weakness and disease phenotype seen in patients. PMID:27112274

  14. Evaluation of genetic variability for heading date and height in triticale obtained by induced mutations and artificial crosses

    International Nuclear Information System (INIS)

    The adjustment of adaptive characters such as heading date and height, allows one to arrange successive cultures and to apply efficient agronomic techniques, resulting in productivity increase. Methods that increase genetic variability have great significance in plant breeding, once they amplify the opportunities for selecting superior genotypes. The aim of this study was to evaluate the effect of induced mutations and reciprocal crosses in families segregating for heading date and height and to analyze the correlation between these characters. The populations were obtained from reciprocal crosses and induced mutation with gamma radiation. In the latter, radiation dosages of 0, 5, 10, 20, 40 kR were obtained from exposition to Cobalt - 60. Changes in the mean and variance in two triticale genotypes Triticale BR4 e EMBRAPAI8, were analyzed. The results obtained indicated families with wide segregation patterns for heading date and height and also suggested the possibility to identify families with distinct values compared to the control population for both characters and both genotypes. There was a tendency to reductions in height and increases in heading date for the families evaluated. However, there was not an expressive correlation between heading date and height for the majority of the treatments, therefore allowing the breeder to select plant types adapted to the environment of cultivation. (author)

  15. Rice breeding with induced mutations II. Report of an FAO/IAEA research co-ordination meeting

    International Nuclear Information System (INIS)

    This report contains the proceedings of the fourth meeting of participants in the FAO/IAEA Co-ordinated Program of Research on the Use of Induced Mutations in Rice Breeding, a program which was initiated in 1964. The three previous meetings were reported as follows: First: proceedings published in the International Rice Commission Newsletter, Vol. XV, No. 1 (1966). Second: report presented to the IRC Working Party meeting at Lake Charles, Louisiana, 18-30 July 1966. Third: proceedings published by the IAEA as Technical Reports Series No. 86 under the title 'Rice breeding with induced mutations'. The fourth meeting was held at Oiso, Japan, on 12-14 August 1968. Co-operators from nine countries attended, together with scientists from five other countries, the International Rice Research Institute, the Rockefeller Foundation, the International Rice Commission, and the FAO and IAEA. In addition, a number of scientists from the host country were present. The purpose of the meeting was to present reports on research related to or carried out under the co-ordinated program in 1967/68, to review and co-ordinate research plans for 1968/69, and to draw up technical recommendations for future work

  16. Induced Mutations for Improved Lycopene, Total Antioxidant Properties and Other Quality Factors in Wild Tomato (Solanum pimpinellifolium L

    Directory of Open Access Journals (Sweden)

    Emmanuel K. Quartey

    2012-08-01

    Full Text Available The objective of the study was to determine biochemical changes in (5 gamma radiation induced variant lines of wild tomato after mutation induction. Five gamma radiation-induced variant lines of wild tomato (Solanum pimpinellifolium L., selected in the M3 generation following mutagenic treatment of seeds using three doses (150, 300 and 450 Gy, respectively of gamma radiation from a Co-60 gamma source, were analysed for their lycopene content, total antioxidant properties, total and soluble solids as well as pH. Fruits of variant line BV-21 (deep red fruits recorded higher lycopene contents of 146.1 mg/kg on fresh weight basis and 156.7 mg/kg on dry weight basis compared to 136 and 152 mg/kg, respectively for the control. They also recorded higher total antioxidant properties compared to the control. Fruits of variant line BV-40 (yellow fruits recorded higher total solids of 17.9% and the lowest pH value of 4.17 compared to 12.8% and 4.36 for fruits from unirradiated plants. The highest amounts of total soluble solids (7% were contained in fruits harvested from variant lines BV-27 (light red fruits and BV-23 (deep red fruits as against 5.6% for fruits from control plants. The study indicates that wild tomato has immense nutritional properties which can be further improved through mutation breeding.

  17. Assessing the potential of an induced-mutation strategy for avermectin overproducers.

    Science.gov (United States)

    Gao, Hong; Liu, Mei; Zhuo, Ying; Zhou, Xianlong; Liu, Jintao; Chen, Difei; Zhang, Wenquan; Gou, Zhongxuan; Shang, Peng; Zhang, Lixin

    2010-07-01

    Mutant libraries of avermectin-producing Streptomyces avermitilis strains were constructed by different mutagenesis strategies. A metric was applied to assess the mutation spectrum by calculating the distribution of average phenotypic distance of each population. The results showed for the first time that a microgravity environment could introduce larger phenotype distribution and diversity than UV and N-methyl-N-nitro-N-nitrosoguanidine (NTG) could. PMID:20453119

  18. Failure of irradiated onion to induce sex-linked recessive lethal mutations in Drosophila melanogaster

    International Nuclear Information System (INIS)

    The feeding of Drosophila for all of their entire larval life plus 2 days as an adult on onion powder that had been irradiated with 15, 950 or 1500 krad did not significantly increase sex-linked recessive lethal mutations. The Drosophila were fed on a mixture that contained 24.5% of onion powder by dry weight. The onion powder had been exposed to a cobalt-60 source of 1.2 million Curies. (orig.)

  19. In Vivo Spectrum of UVC-induced Mutation in Mouse Skin Epidermis May Reflect the Cytosine Deamination Propensity of Cyclobutane Pyrimidine Dimers.

    Science.gov (United States)

    Ikehata, Hironobu; Mori, Toshio; Yamamoto, Masayuki

    2015-11-01

    Although ultraviolet radiation (UVR) has a genotoxicity for inducing skin cancers, the skin may tolerate UVC component because the epidermal layer prevents this short wavelength range from passing through. Here, UVC genotoxicity for mouse skin was evaluated in terms of DNA damage formation and mutagenicity. UVC induced UVR photolesions and mutations remarkably in the epidermis but poorly in the dermis, confirming the barrier ability of the epidermis against shorter UVR wavelengths. Moreover, the epidermis itself responded to UVC mutagenicity with mutation induction suppression, which suppressed the mutant frequencies to a remarkably low, constant level regardless of UVC dose. The mutation spectrum observed in UVC-exposed epidermis showed a predominance of UV-signature mutation, which occurred frequently in 5'-TCG-3', 5'-TCA-3' and 5'-CCA-3' contexts. Especially, for the former two contexts, the mutations recurred at several sites with more remarkable recurrences at the 5'-TCG-3' sites. Comparison of the UVC mutation spectrum with those observed in longer UVR wavelength ranges led us to a mechanism that explains why the sequence context preference of UV-signature mutation changes according to the wavelength, which is based on the difference in the mCpG preference of cyclobutane pyrimidine dimer (CPD) formation among UVR ranges and the sequence context-dependent cytosine deamination propensity of CPD. PMID:26335024

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

    Energy Technology Data Exchange (ETDEWEB)

    Vreeswijk, Maaike P.G., E-mail: vreeswijk@lumc.nl [Department of Toxicogenetics, Leiden University Medical Center, Einthovenweg 20, P.O. Box 9600, Postzone S4-P, 2300 RC Leiden (Netherlands); Department of Human Genetics, Center for Human and Clinical Genetics, Leiden University Medical Center, Building 2, Postzone S-04, P.O. Box 9600, 2300 RC Leiden (Netherlands); Meijers, Caro M.; Giphart-Gassler, Micheline; Vrieling, Harry; Zeeland, Albert A. van; Mullenders, Leon H.F.; Loenen, Wil A.M. [Department of Toxicogenetics, Leiden University Medical Center, Einthovenweg 20, P.O. Box 9600, Postzone S4-P, 2300 RC Leiden (Netherlands)

    2009-04-26

    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.

  1. Mitochondrial COX2 G7598A Mutation May Have a Modifying Role in the Phenotypic Manifestation of Aminoglycoside Antibiotic-Induced Deafness Associated with 12S rRNA A1555G Mutation in a Han Chinese Pedigree

    Science.gov (United States)

    Chen, Tianbin; Liu, Qicai; Jiang, Ling; Liu, Can

    2013-01-01

    Recent studies suggest that certain mitochondrial haplogroup markers and some specific variants in mitochondrial haplogroup may also influence the phenotypic expression of particular mitochondrial disorders. In this report, the clinical, genetic, and molecular characterization were identified in a Chinese pedigree with the aminoglycoside antibiotic (AmAn)-induced deafness and nonsyndromic hearing loss (NSHL). The pathogenic gene responsible for this hereditary NSHL pedigree was determined by Microarray chip, which possessed the nine NSHL hot-spot mutations, including GJB2 (35delG, 176dell6bp, 235de1C, and 299delAT), GJB3 (538C>T), SLC26A4 (IVS7-2A>G and 2168A>G), and mitochondrial DNA (mtDNA) 12S rRNA (C1494T and A1555G). Only the homoplasmic A1555G mutation was detected, which was confirmed by direct sequencing. Also, real-time amplification refractory mutation system quantitative polymerase chain reaction methodology was performed to calculate the A1555G mutation load. The proband's complete mtDNA genome were amplified and direct sequencing was performed to determine the mitochondrial haplogroup and private mutations. The proband's mitochondrial haplogroup belonges to M7b1 and a private mutation MTCOX2 G7598A (p.Ala 5 Thr) is found. Phylogenetic analysis of COX2 polypeptide sequences demonstrates that the alanine residue is relatively conserved, but owing to the missense mutation (p.Ala 5 Thr), its side chain hydrophobicity will be changed, and what is more, as it is adjacent to a glutamine residue, which is highly conserved and hydrophilic, in an evolutionary stable domain; G7598A (p.Ala 5 Thr) may alter the protein secondary structure and physiological function of COX2 and, thus, aggravate the mitochondrial dysfunction conferred by the A1555G mutation. Furthermore, the G7598A mutation is absent in 100 unrelated healthy controls; therefore, G7598A (p.Ala 5 Thr) in the mitochondrial haplogoup M7b1 may have a modifying role, enhancing its penetrance and severity

  2. Radiation-induced dominant skeletal mutations in mice: mutation rate, characteristics, and usefulness in estimating genetic hazard to humans from radiation

    Energy Technology Data Exchange (ETDEWEB)

    Selby, P. B.

    1979-05-01

    The work discussed in this paper represents a major advance in the difficult task of trying to estimate the effects that an increase in mutation frequency would have on human health. Male mice were bred to three females prior to being killed and skeleton studies made. Guidelines were instituted for checking progeny mutations. Surprising results showed a mutation frequency of 1.4% per gamete where none would have been expected. It is now clear that mice can be greatly deformed without showing external effects. (PCS)

  3. Radiation-induced dominant skeletal mutations in mice: mutation rate, characteristics, and usefulness in estimating genetic hazard to humans from radiation

    International Nuclear Information System (INIS)

    The work discussed in this paper represents a major advance in the difficult task of trying to estimate the effects that an increase in mutation frequency would have on human health. Male mice were bred to three females prior to being killed and skeleton studies made. Guidelines were instituted for checking progeny mutations. Surprising results showed a mutation frequency of 1.4% per gamete where none would have been expected. It is now clear that mice can be greatly deformed without showing external effects

  4. Antimutagenic effect of essential oil of sage (Salvia officinalis L. and its fractions against UV-induced mutations in bacterial and yeast cells

    Directory of Open Access Journals (Sweden)

    Knežević-Vukčević Jelena B.

    2005-01-01

    Full Text Available The inhibition of spontaneous and UV-induced mutations by essential oil (EO of sage (Salvia officinalis L. and its fractions F1-F5 containing different proportions of mono- and sesquiterpenes was studied with the Salmonella/microsome, E. coli K12, and S. cerevisiae D7 reversion assays. The EO, F1, and F2 exhibited antimutagenic potential against UV-induced mutations in all tests. Fractions F3 and F4 produced a toxic, mutagenic, or antimutagenic response, depend­ing on the test organism used. Reduction of spontaneous and UV-induced mutations by F5 was detected only in permeable strains of E. coli. The obtained results demonstrate antimutagenic activity of volatile sage terpenes and recommend them for further antimutagenesis and anticarcinogenesis studies.

  5. Application Of Induced Mutation Combined With Hybridization Method In Rice Improvement In Southern Vietnam

    International Nuclear Information System (INIS)

    Rice plays an important role of social-economic issues in Vietnam, especially in Mekong River Delta (MRD). Rice mutation breeding was not initiated until 1992 in Southern Vietnam. Therefore, no mutant rice varieties were cultivated in MRD before 1995. Dry and germinated seeds of varieties as IR64, Tam Xoan, Nang Huong were exposed to 60 Co gamma rays at doses of 200-300 Gy. Population of 10,000-15,000 M1 plants were established by direct seeded practice. Mutant elite lines were used in hybridization program, assessed according to the standard system for rice (IRRI 1996) from M2 - M7 generations. The promising selected lines were tested in multi-location trials. The mutated characters developed so far consist of better resistance to lodging, disease and insect damages, higher tolerance to soil stresses such as acid sulphate, drought etc, and also earliness and higher yield potential. Mutation techniques have shown very useful in rice improvement, especially for characters controlled by close linked genes that are difficult to break by recombination. Some best mutant varieties: VND95-19, VND95-20, VND99-3, TNDB-100 have been released for large-scale production in MRD. Among them, VND95-20 has become one of the top 5 varieties for export and grown annually about 300,000 ha in Southern Vietnam. In combination with hybridization method, some mutants gave promising recombinants in aroma, tolerance to BPH, Grassy Stunt Virus and Ragged Stunt Virus diseases. Selected varieties as VN121, VN24-4 are largely released into production in recent time. (author)

  6. Analysis of relation between the mutation frequencies and somatic recombination induced by neutrons and the age of D. Melanogaster larvae

    International Nuclear Information System (INIS)

    Neutrons are subatomic particles with neutral electric charge, equal zero, which are emitted during the fissile material fission in nuclear reactors. It is known a little about biological effects induced by neutrons. There is a world interest in the use of reactors and accelerators for patients radiotherapy using neutrons with the purpose to destroy malignant cells of deep tumours where traditional methods have not given satisfactory results. There for it is required to do wide studies of biological effects of neutrons as well as their dosimetry. It was used the Smart test (Somatic Mutation and Recombination Test) of D. Melanogaster for quantifying the mutation induction and somatic recombination induced by neutrons of the National Institute of Nuclear Research reactor, at power of 300 and 1000 k W, with equivalent doses calculated 95.14 and 190.2 Sv for 300 k W and of 25.64 and 51.29 Sv for 1000 k W, using larvae with 72 or 96 hours aged. It was observed a linear relation between equivalent dose and genetic effects frequency, these last were greater when the reactor power was 1000 k W than those 300 k W. It was observed too that the damage was greater in 96 hours larvae than those 72 hours. The stain size presented an inverse relation with respect to larvae age. It is concluded that the Smart system is sensitive to neutrons effect and it responds of a directly proportional form to radiation dose, as well as to dose rate. It is noted more the effect when are used larvas in pre pupa stage where the irradiation target (imagal cells) is greater. The Smart is sensitive to damage induced by neutrons , thus can be used to studying its direct biological effects or by the use of chemical modulators. (Author)

  7. Study on toxicity mutation of crown-vetch induced by radiation

    International Nuclear Information System (INIS)

    The suckers of Germany crown-vetch were irradiated by 60Co gamma ray and fast neutron. The toxicity mutation frequency and genetic stability of crown-vetch were studied. The various toxicity mutants were found in M1. Most of the toxicity mutants was unstable in M2, Stable mutant was very few (about 2.0-12.9%). β-nitropropionic acid in the low toxicity mutants selected was 31.7-39.8 mg/g. Genetic characteristics of low toxicity mutants were stable in M3-M5

  8. Molecular analysis of heavy ion induced mutations in the budding yeast

    International Nuclear Information System (INIS)

    The aim of this study is to elucidate the molecular mechanism of mutagenesis caused with heavy ion irradiation. Yeast cells were irradiated with accelerated carbon ion (290 MeV/u, 13-75 keV/mm) and helium ion (150 MeV/u, 2.2 keV/mm). The survival rate of carbon ion beam irradiated cells was reduced with linear energy transfer (LET), and the mutation frequency increased consistently with LET. The survival rate of helium ion beam (0.45 keV/mm) was slightly higher than that of carbon ion beam (LET: 25 keV/ mm) irradiated cells. (author)

  9. Induced mutations and molecular techniques for crop improvement. Proceedings of an international symposium

    International Nuclear Information System (INIS)

    The symposium was aimed at reviewing current aspects of mutation and molecular biology techniques for use in crop improvement and to bridge the gap between practical plant breeding and molecular laboratory techniques. Over the past few years, many transgenic plants have been developed in important crops such as rice, wheat, maize, soybean, banana, cassava and cotton, as well as in many food, industrial and pharmaceutical plant species. More than 180 participants from 48 countries of which 31 were from developing countries, attended which provided a forum for the discussion of problems related to crop improvement world wide, and their possible solutions. Refs, figs and tabs

  10. Dominant lethal mutation induced by continuous irradiation of 60Co gamma rays in mice

    International Nuclear Information System (INIS)

    Female and male mice were exposed to 60Co gamma rays for 10 days, the accumulative doses were 0.396-2.024 and 0.462-2.552 Gy respectively. The number of dominant lethal mutations was calculated as follows: PRE = CL - (ED + LD + VIA). The results showed that Preimplantation Loss (PRE) ranged from 1.222 to 3.714 for female mice and 0.0345 to 2.2308 for male mice. In both cases a linear dose-effect relationship was observed. The PRE of oocytes is 1.66 times higher than that of spermatids

  11. Identification of potential molecular markers of ionizing radiation-induced mutations at the hprt locus in CHO cells

    International Nuclear Information System (INIS)

    Using multiplex polymerase chain reaction-based exon deletion analysis, we have analyzed mutations at the hprt locus from independent CHO cell mutants isolated from untreated, 60Co x-ray-, and 212Bi-exposed CHO-K1 cello and its radiation-sensitive derivative, xrs-5. In the 71 spontaneous CHO-K1 mutants analyzed, 78% showed no change in exon number or size, 20% showed loss of 1-8 exons (partial deletion), and 3% showed loss of all nine hprt exons (total deletion). Exposure of CHO-K1 cells to 6 Gy of γ rays (10% survival) produced 45% of the 20 mutants analyzed showing partial deletion, and 30% showing total deletion. Exposure to an equitoxic dose of a radiation from 212Bi, a 220Rn daughter, resulted in a spectrum similar to the γ-ray spectrum in that more than 75% of the 49 mutants analyzed were deletions. The α-radiation, however, tended to produce larger intragenic deletions that γ radiation. Of the 87 spontaneous xrs-5 mutants analyzed for deletions 44% showed partial deletion, and 14% showed total deletion. Exposure to α radiation (10% survival) resulted in a deletion spectrum similar to that seen in CHO-K1 cells. Of the 49 mutants analyzed, 43% showed no change in exon number or size, 16% showed partial deletion, and 41% showed total deletion. While the defect in xrs-5 has a profound effect on spontaneous mutation spectra, it does not appear to affect α-induced mutation spectra

  12. Precise Correction of Disease Mutations in Induced Pluripotent Stem Cells Derived From Patients With Limb Girdle Muscular Dystrophy.

    Science.gov (United States)

    Turan, Soeren; Farruggio, Alfonso P; Srifa, Waracharee; Day, John W; Calos, Michele P

    2016-04-01

    Limb girdle muscular dystrophies types 2B (LGMD2B) and 2D (LGMD2D) are degenerative muscle diseases caused by mutations in the dysferlin and alpha-sarcoglycan genes, respectively. Using patient-derived induced pluripotent stem cells (iPSC), we corrected the dysferlin nonsense mutation c.5713C>T; p.R1905X and the most common alpha-sarcoglycan mutation, missense c.229C>T; p.R77C, by single-stranded oligonucleotide-mediated gene editing, using the CRISPR/Cas9 gene-editing system to enhance the frequency of homology-directed repair. We demonstrated seamless, allele-specific correction at efficiencies of 0.7-1.5%. As an alternative, we also carried out precise gene addition strategies for correction of the LGMD2B iPSC by integration of wild-type dysferlin cDNA into the H11 safe harbor locus on chromosome 22, using dual integrase cassette exchange (DICE) or TALEN-assisted homologous recombination for insertion precise (THRIP). These methods employed TALENs and homologous recombination, and DICE also utilized site-specific recombinases. With DICE and THRIP, we obtained targeting efficiencies after selection of ~20%. We purified iPSC corrected by all methods and verified rescue of appropriate levels of dysferlin and alpha-sarcoglycan protein expression and correct localization, as shown by immunoblot and immunocytochemistry. In summary, we demonstrate for the first time precise correction of LGMD iPSC and validation of expression, opening the possibility of cell therapy utilizing these corrected iPSC. PMID:26916285

  13. Rasfonin, a novel 2-pyrone derivative, induces ras-mutated Panc-1 pancreatic tumor cell death in nude mice.

    Science.gov (United States)

    Xiao, Z; Li, L; Li, Y; Zhou, W; Cheng, J; Liu, F; Zheng, P; Zhang, Y; Che, Y

    2014-01-01

    Rasfonin is a novel 2-pyrone derivative reported to induce apoptosis in ras-dependent cells. In this study, its effects on ras-mutated pancreatic cancer cells were investigated in vitro and in vivo. Two human pancreatic cancer cell lines Panc-1 (mutated K-ras) and BxPC-3 (wild-type K-ras) were selected to test the effects of rasfonin on cell proliferation, clone formation, migration and invasion in vitro. Immunoblotting was used to detect the expressions of EGFR-Ras-Raf-MEK-ERK signaling pathway proteins. Ras activity was measured using a pull-down ELISA kit and guanine exchange factor (GEF)/GTPase-activating proteins (GAP) activity was measured by [(3)H]-GDP radiometric ligand binding. For an in vivo study, CD1 nude mice bearing Panc-1 cells were treated with rasfonin or Salirasib (FTS). We found that rasfonin suppressed proliferation more strongly in Panc-1 cells (IC50=5.5 μM) than BxPC-3 cells (IC50=10 μM) in vitro. Clone formation, migration and invasion by Panc-1 cells were also reduced by rasfonin. Rasfonin had little effect on the farnesylation of Ras, but it strongly downregulated Ras activity and consequently phosphorylation of c-Raf/MEK/ERK. Further experiments indicated that rasfonin reduced Son of sevenless (Sos1) expression but did not alter GEF and GAP activities. The in vivo experiments also revealed that rasfonin (30 mg/kg) delayed the growth of xenograft tumors originating from Panc-1 cells. Tumor weight was ultimately decreased after 20 days of treatment of rasfonin. Rasfonin is a robust inhibitor of pancreatic cancers with the K-ras mutation. The reduction of Sos1 expression and the consequently depressed Ras-MAPK activity could be important in its anticancer activity. PMID:24853419

  14. Genetics of the radiation-induced yellow vein mosaic disease resistance mutation in okra

    International Nuclear Information System (INIS)

    The yellow vein mosaic disease (YVMD) is one of the major diseases affecting okra production in Thailand. YVMD-resistant B4610 mutant was generated through gamma irradiation of the Okura variety of okra. In an attempt to develop a DNA marker for YVMD-resistance, a BC1F1 and an F2 mapping population were generated from the cross between B4610 and Pichit 03, a YVMD-susceptible variety. The populations were naturally inoculated with YVMD virus in the field at Pichit Horticultural Research Center, Pichit province, where the disease is widespread. Analysis of F1 and F2 progeny revealed the semi-dominant nature of the resistance which appeared to be caused by a single-locus mutation. AFLP and MFLP fingerprintings of the F2 and the BC1F1 population revealed DNA fragments that are potentially linked to the mutation. In addition to the visual assessment of YVMD, a PCR method was developed for the assay of the presence of YVMD virus in leaf tissues. Sequencing of the amplified DNA fragments confirmed the presence of okra YVMD virus in the infected leaf tissues in susceptible plants. (author)

  15. Genetics of the Radiation-Induced Yellow Vein Mosaic Disease Resistance Mutation in Okra

    International Nuclear Information System (INIS)

    Yellow vein mosaic disease (YVMD) is one of the major diseases affecting okra production in Thailand. YVMD-resistant B4610 mutant was generated through gamma irradiation of the Okura variety of okra. In an attempt to develop a DNA marker for YVMD-resistance, a BC1F1 and an F2 mapping population were generated from the cross between B4610 and Pichit 03, a YVMD-susceptible variety. The populations were naturally inoculated with YVMD virus in the field at Pichit Horticultural Research Center, Pichit province, where the disease is widespread. Analysis of F1 and F2 progeny revealed the semi-dominant nature of the resistance which appeared to be caused by a single-locus mutation. MFLP fingerprintings of the F2 and the BC1F1 populations revealed a DNA fragment that is potentially linked to the mutation. In addition to the visual assessment of YVMD, a PCR method was developed for the assay of the presence of YVMD virus in leaf tissues. Sequencing of the amplified DNA fragments confirmed the presence of okra YVMD virus in the infected leaf tissues in susceptible plants. (author)

  16. Radiation-induced mutations in sweet cherry (Prunus avium L. ) cvs Napoleon and Bing

    Energy Technology Data Exchange (ETDEWEB)

    Saamin, S.

    1987-01-01

    Experiments were conducted using gamma radiation to determine radiosensitivities of main and accessory buds, to increase the proportion of mutant tissue, and to determine the type of damage and mode of recovery in irradiated shoot spices of sweet cherry cvs Napoleon and Bin. Survival, growth, and the types of mutations of V/sub 1/ (primary) shoots and V/sub 2/ plants were observed. LD/sub 50/ values, based on survival of forced buds were about 5kR for both acute and fractionated irradiation in air, 5.5kR for acute exposure in water, and 6kR for fractionated dose in water. 0.39-0.69 accessory buds/site on non-irradiated Napoleon had forced after 30 days in the glasshouse. In the Bing field experiment with main buds, the LD/sub 50/ for both acute and fractionated irradiation in air was 3.5kR. In water, the LD/sub 50/ was 5kR for acute treatment and 6.5kR for fractionated dose. The overall mutation frequency in Napoleon V/sub 2/ shoots derived from main buds was 7.6%: 0.04% growth-reduced mutants, 0.4% total leaf mutants, and7.1% partial leaf mutants.

  17. Point mutation impairs centromeric CENH3 loading and induces haploid plants.

    Science.gov (United States)

    Karimi-Ashtiyani, Raheleh; Ishii, Takayoshi; Niessen, Markus; Stein, Nils; Heckmann, Stefan; Gurushidze, Maia; Banaei-Moghaddam, Ali Mohammad; Fuchs, Jörg; Schubert, Veit; Koch, Kerstin; Weiss, Oda; Demidov, Dmitri; Schmidt, Klaus; Kumlehn, Jochen; Houben, Andreas

    2015-09-01

    The chromosomal position of the centromere-specific histone H3 variant CENH3 (also called "CENP-A") is the assembly site for the kinetochore complex of active centromeres. Any error in transcription, translation, modification, or incorporation can affect the ability to assemble intact CENH3 chromatin and can cause centromere inactivation [Allshire RC, Karpen GH (2008) Nat Rev Genet 9 (12):923-937]. Here we show that a single-point amino acid exchange in the centromere-targeting domain of CENH3 leads to reduced centromere loading of CENH3 in barley, sugar beet, and Arabidopsis thaliana. Haploids were obtained after cenh3 L130F-complemented cenh3-null mutant plants were crossed with wild-type A. thaliana. In contrast, in a noncompeting situation (i.e., centromeres possessing only mutated or only wild-type CENH3), no uniparental chromosome elimination occurs during early embryogenesis. The high degree of evolutionary conservation of the identified mutation site offers promising opportunities for application in a wide range of crop species in which haploid technology is of interest. PMID:26294252

  18. Characterization of Cat-2t, a radiation-induced dominant cataract mutation in mice

    International Nuclear Information System (INIS)

    A dominant cataract mutation was detected recently among the offspring of x-ray-irradiated male mice. The mutation, which causes total lens opacity, has provisionally been designated by the gene symbol Cat-2t. In the lenses of heterozygous and homozygous Cat-2t mutants, the epithelial and fiber cells were swollen and the lens capsule was ruptured. The histologic analysis demonstrated a complete destruction of the cellular organization of the lens, which might be caused by its altered developmental processes. The data derived from biochemical investigations indicate that biochemistry of the cataractous Cat-2t lenses is affected: the osmotic state as indicated by the increased water content and increased Na(+)-K(+)-adenosinetriphosphatase (ATPase) activity; the energy state as indicated by the decreased adenosine triphosphate (ATP) concentration; and the redox state as indicated by the enhanced content of oxidized glutathione. Additionally, the lenticular protein composition is altered because of the presence of vimentin in the water-soluble fraction. This cannot be explained by the enhanced crosslinking activity of transglutaminase. The changes of the osmotic, energy, and redox states are considered to be secondary in relation to the altered lenticular development. In contrast, the variations concerning vimentin and transglutaminase might be a biochemical indication of the changed development. Possible similarities to other dominantly expressed murine cataract mutants are discussed

  19. Induced mutation of Egypt cotton variety and selection of long fiber cotton mutant by irradiation

    International Nuclear Information System (INIS)

    In order to obtain long fiber cotton variety which would be adaptable to the ecological conditions of Yellow River Region, the mutation induction of Egypt cotton variety, Ashmouni, was carried out by γ-ray of 279 Gy in 1985. In M1 generation, serious radiation damage was shown in seed-lings, the death percentage of seedling was 63.3%. Two plants with early maturity were selected and their seeds were planted individually in 1986. The complex segregation appeared in M2 generation. The selection and domestication were carried out for several years and four stable mutant lines which included early maturity, dwarf plant, compact pattern, stranger bollbearing ability as well as upland cotton characters were obtained in 1991. The fiber length of these lines reached 33 ∼ 35 mm, and the mutants were adaptable to ecological condition in Shandong Province. The mutant line, 90197-1, whose growing period and plant height shorter than those of upland cotton cultivar, Zhong-mian No.12, has compact plant pattern, high bollbearing ability and ginning out turn of about 40%. Further yield test is required for these lines. The hereditary variability of the progeny in mutated Egypt cotton variety, preliminary cytological observation and the analysis of isoenzyme in mutants are also discussed

  20. SCN5A mutation in patients with Brugada electrocardiographic pattern induced by fever

    Institute of Scientific and Technical Information of China (English)

    俞建华

    2014-01-01

    Objective To explore the relationship between SCN5A,SCN1b,SCN3b and GPD1L genotypes and the risk of malignant arrhythmia in patients with Brugada electrocardiographic pattern induced by fever.Methods The clinical data and peripheral blood of patients with Brugada electrocardiographic pattern induced by fever were

  1. Presenilin-1 regulates induction of hypoxia inducible factor-1α: altered activation by a mutation associated with familial Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Sosa Miguel

    2010-09-01

    Full Text Available Abstract Background Mutations in presenilin-1 (Psen1 cause familial Alzheimer's disease (FAD. Both hypoxia and ischemia have been implicated in the pathological cascade that leads to amyloid deposition in AD. Here we investigated whether Psen1 might regulate hypoxic responses by modulating induction of the transcription factor hypoxia inducible factor 1-α (HIF-1α. Results In fibroblasts that lack Psen1 induction of HIF-1α was impaired in response to the hypoxia mimetic cobalt chloride, as well as was induction by insulin and calcium chelation. Reintroduction of human Psen1 using a lentiviral vector partially rescued the responsiveness of Psen1-/- fibroblasts to cobalt chloride induction. HIF-1α induction did not require Psen1's associated γ-secretase activity. In addition, the failure of insulin to induce HIF-1α was not explicable on the basis of failed activation of the phosphatidylinositol 3-kinase (PI3K/Akt pathway which activated normally in Psen1-/- fibroblasts. Rather we found that basal levels of HIF-1α were lower in Psen1-/- fibroblasts and that the basis for lower constitutive levels of HIF-1α was best explained by accelerated HIF-1α degradation. We further found that Psen1 and HIF-1α physically interact suggesting that Psen1 may protect HIF-1α from degradation through the proteasome. In fibroblasts harboring the M146V Psen1 FAD mutation on a mouse Psen1 null background, metabolic induction of HIF-1α by insulin was impaired but not hypoxic induction by cobalt chloride. Unlike Psen1-/- fibroblasts, basal levels of HIF-1α were normal in FAD mutant fibroblasts but activation of the insulin-receptor pathway was impaired. Interestingly, in Psen1-/- primary neuronal cultures HIF-1α was induced normally in response to cobalt chloride but insulin induction of HIF-1α was impaired even though activation of the PI3K/Akt pathway by insulin proceeded normally in Psen1-/- neuronal cultures. Basal levels of HIF-1α were not

  2. Cytologic Investigations on Identification of Induced Mutation Effects in Sultani Çekirdeksiz ve Kalecik Karası Grape cvs. (Vitis vinifera L.)

    International Nuclear Information System (INIS)

    The effects of induced mutation applied by 5 different doses of gamma irradiation (20, 25, 30, 40 ve 50 Gy) were cytologic investigated on Vitis vinifera L. cultivars, Sultani Çekirdeksiz (SÇ) ve Kalecik karası (KK). Mutant candidates were selected through the morphological observations of the mutation-induced phenotypic changes in the first (M1V1), second (M1V2) and third (M1V3) vegetations. In cytological studies, diploid cells (2n=38) were observed for both cultivars. Cells showing ploidy level other than diploidy were found only in the individual SÇ 30 Gy 34. (author)

  3. Arsenic trioxide and all-trans retinoic acid target NPM1 mutant oncoprotein levels and induce apoptosis in NPM1-mutated AML cells.

    Science.gov (United States)

    Martelli, Maria Paola; Gionfriddo, Ilaria; Mezzasoma, Federica; Milano, Francesca; Pierangeli, Sara; Mulas, Floriana; Pacini, Roberta; Tabarrini, Alessia; Pettirossi, Valentina; Rossi, Roberta; Vetro, Calogero; Brunetti, Lorenzo; Sportoletti, Paolo; Tiacci, Enrico; Di Raimondo, Francesco; Falini, Brunangelo

    2015-05-28

    Nucleophosmin (NPM1) mutations represent an attractive therapeutic target in acute myeloid leukemia (AML) because they are common (∼30% AML), stable, and behave as a founder genetic lesion. Oncoprotein targeting can be a successful strategy to treat AML, as proved in acute promyelocytic leukemia by treatment with all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO), which degrade the promyelocytic leukemia (PML)-retinoic acid receptor fusion protein. Adjunct of ATRA to chemotherapy was reported to be beneficial for NPM1-mutated AML patients. Leukemic cells with NPM1 mutation also showed sensibility to ATO in vitro. Here, we explore the mechanisms underlying these observations and show that ATO/ATRA induce proteasome-dependent degradation of NPM1 leukemic protein and apoptosis in NPM1-mutated AML cell lines and primary patients' cells. We also show that PML intracellular distribution is altered in NPM1-mutated AML cells and reverted by arsenic through oxidative stress induction. Interestingly, similarly to what was described for PML, oxidative stress also mediates ATO-induced degradation of the NPM1 mutant oncoprotein. Strikingly, NPM1 mutant downregulation by ATO/ATRA was shown to potentiate response to the anthracyclin daunorubicin. These findings provide experimental evidence for further exploring ATO/ATRA in preclinical NPM1-mutated AML in vivo models and a rationale for exploiting these compounds in chemotherapeutic regimens in clinics. PMID:25795919

  4. Epigenetic Characterization of the FMR1 Promoter in Induced Pluripotent Stem Cells from Human Fibroblasts Carrying an Unmethylated Full Mutation

    Directory of Open Access Journals (Sweden)

    Celine E.F. de Esch

    2014-10-01

    Full Text Available Silencing of the FMR1 gene leads to fragile X syndrome, the most common cause of inherited intellectual disability. To study the epigenetic modifications of the FMR1 gene during silencing in time, we used fibroblasts and induced pluripotent stem cells (iPSCs of an unmethylated full mutation (uFM individual with normal intelligence. The uFM fibroblast line carried an unmethylated FMR1 promoter region and expressed normal to slightly increased FMR1 mRNA levels. The FMR1 expression in the uFM line corresponds with the increased H3 acetylation and H3K4 methylation in combination with a reduced H3K9 methylation. After reprogramming, the FMR1 promoter region was methylated in all uFM iPSC clones. Two clones were analyzed further and showed a lack of FMR1 expression, whereas the presence of specific histone modifications also indicated a repressed FMR1 promoter. In conclusion, these findings demonstrate that the standard reprogramming procedure leads to epigenetic silencing of the fully mutated FMR1 gene.

  5. CYP2U1 mutations in two Iranian patients with activity induced dystonia, motor regression and spastic paraplegia

    Science.gov (United States)

    Kariminejad, A.; Schöls, L.; Schüle, R.; Tonekaboni, S.H.; Abolhassani, A.; Fadaee, M.; Rosti, R.O.; Gleeson, J.G.

    2016-01-01

    Hereditary spastic paraplegia (HSP) is a heterogeneous condition characterized by progressive spasticity and weakness in the lower limbs. It is divided into two major groups, complicated and uncomplicated, based on the presence of additional features such as intellectual disability, ataxia, seizures, peripheral neuropathy and visual problems. SPG56 is an autosomal recessive form of HSP with complicated and uncomplicated manifestations, complicated being more common. CYP2U1 gene mutations have been identified as responsible for SPG56. Intellectual disability, dystonia, subclinical sensory motor neuropathy, pigmentary degenerative maculopathy, thin corpus callosum and periventricular white-matter hyperintensities were additional features noted in previous cases of SPG56. Here we identified two novel mutations in CYP2U1 in two unrelated patients by whole exome sequencing. Both patients had complicated HSP with activity-induced dystonia, suggesting dystonia as an additional finding in SPG56. Two out of 14 previously reported patients had dystonia, and the addition of our patients suggests dystonia in a quarter of SPG56 patients. Developmental regression has not been reported in SPG56 patients so far but both of our patients developed motor regression in infancy. PMID:27292318

  6. Radiation induced mutation to develop dwarf and precocious lines of papaya

    International Nuclear Information System (INIS)

    Papaya (Carica papaya L.) is one of the most important fruit cultivated throughout the tropical and subtropical regions of the country. Almost all the varieties of papaya developed either through selection or hybridization. As regards mutation breeding, very little work has been done in India. Only one variety PusaNanha has been developed through mutation breeding by treating the seed of papaya strain Pusa 1-15 with 15Kr gamma rays. Mutation breeding is the most appropriate for improving one or two easily identifiable traits in an otherwise well accepted breeding lines or commercial variety. Dwarfness and earliness in flowering are important traits in high density planting as breeding objective for improving papaya varieties for high yield with medium size fruits and good fruit quality. With these objectives, seeds of the papaya P 7-2 were treated with gamma rays 0.1, 0.15, 0.2, 0.25 and 0.3 kGy. The control recorded maximum germination (68%). Among the other treatments maximum germination (64.25%) was recorded at 0.1 kGy. The germination percentage was observed to be least (45%) at 0.3 kGy. Minimum length of seedlings (8.5 cm) and diameter (3.92 mm) was recorded in treatment 0.1 kGy while maximum length (19.2 cm) and diameter (6.26 mm) was recorded in treatment 0.3 kGy after 30 days of sowing. Minimum height of the plant (79.24 cm) was recorded in treatment 0.1 kGy while maximum (112.20) in control. Minimum plant girth (33.40 cm) was measured in 0.3 kGy while maximum (44.34 cm) in 0.15 kGy treatment. Minimum height at first flower initiation (55.28 cm), days to flower initiation (78.28) and length of petiole (60.45 cm) was noted in treatment 0.1 kGy while maximum height at first flower initiation (78.2 cm), days to flower initiation (87.46) and length of petiole (68.24 cm) was found in control. Among treatments, maximum number (18) of fruit was counted in 0.3 kGy treatment while maximum weight of fruit (750 g) was recorded in control. Maximum TSS (10.6 °Brix) in

  7. Comparative evolutionary analyses of beta globin gene in eutherian, dinosaurian and neopterygii taxa

    Directory of Open Access Journals (Sweden)

    Gauri Awasthi, Garima Srivastava & Aparup Das

    2011-03-01

    Full Text Available Background & objectives: Comparative genomics and evolutionary analyses of conserved genes have enabled usto understand the complexity of genomes of closely related species. For example: -globin gene present inhuman hemoglobin is one such gene that has experienced many genetic changes in many related taxa andproduced more than 600 variants. One of the variant, HBS causes sickle-cell anemia in humans but offersprotection against severe malaria due to Plasmodium falciparum. In the present study, we characterized andperformed evolutionary comparative analyses of the -globin gene in different related and unrelated taxa tohave a comprehensive view of its evolution.Methods: DNA and protein sequences of -globin gene were downloaded from NCBI and characterized in detailin nine eutherian (Homo sapiens, Pan troglodytes, Macaca mulatta, Mus musculus, Rattus norvegicus, Bostaurus, Canis familiaris, Equus caballus, Oryctolagus cuniculus, a dinosaurian (Gallus gallus and a neopterygii(Danio rerio taxa. Three more eutherian (Papio anubis, Ovis aries and Sus scrofa taxa were included for ananalysis at the protein level but not included at the gene level owing to lack of genomic information. Computationaland phylogenetic analyses were performed using evolutionary comparative approach.Results: Results of comparative and phylogenetic analyses revealed less conservation of genetic architecture of-globin compared to its protein architecture in all eutherian taxa. Both dinosaurian and neopterygii taxa servedas outgroups and varied at gene and protein levels.Interpretation & conclusion: Most remarkably, all primates from eutherian taxa including P. anubis showedonly nine codon position differences and an absolute similarity between H. sapiens and P. troglodytes. Absoluteconservation of coding region in Equus caballus (horse was observed. The results were discussed with aninference on the role of evolutionary forces in maintaining such close similarities and variations across closelyrelated taxa. Further, the need to utilize more comparative approaches in understanding the disease causinggenes’ evolution in closely related taxa is hoped for.

  8. Distribution of beta-globin haplotypes among the tribes of southern Gujarat, India.

    Science.gov (United States)

    Aggarwal, Aastha; Khurana, Priyanka; Mitra, Siuli; Raicha, Bhavesh; Saraswathy, K N; Italia, Yazdi M; Kshatriya, Gautam K

    2013-06-01

    The present study was carried out in Indo-European speaking tribal population groups of southern Gujarat (India) to elucidate the allelic and haplotypic content of β-globin system in individuals with HbAA genotypes. 6 neutral restriction sites of the β-globin system were analysed and various statistical parameters were estimated to draw meaningful interpretations. All the 6 sites were found to be polymorphic and most were in Hardy-Weinberg Equilibrium in the studied group. Haplotypes were constructed using two different combinations of the 6 restriction sites analysed. Analysis of the 5 sites revealed a set of three predominant haplotypes, '+----', '-++-+' and '-+-++'; and haplotypes '+--', '++-' and '+++' were found to be the most frequent when the 3 sites were used to construct the haplotypes. Haplotypic heterozygosity levels (>83%) observed in the present study group were comparable to those observed in African and Afro-American populations and greater than other world populations. All the ancestral haplotypes, +-----, -++-+, -+-++ and ----+ were found in the study group. The distribution pattern of various haplotypes was consistent with the global pattern. The paucity of comparable data from other Indian populations restricted one from making interpretations about the study group's relationships with other Indian populations but the results were indicative of older population histories or experience of gene flow by the study group and their affinities with populations of southern India. PMID:23500448

  9. Photoreactivation of UV induced cell killing, chromosome aberrations, sister chromatide exchanges, mutations and pyrimidine dimers in Xenopus laevis fibroblasts

    International Nuclear Information System (INIS)

    Fibroblasts from Xenopus laevis, which posses photoreactivating enzyme were used to study the influence of photoreactivating light on the frequency of pyrimidine dimers in DNA, chromosomal aberrations, sister chromatid exchanges, cell killing and the induction of gene mutations (ouabain-resistance) induced by 254 nm ultraviolet irradiation. The frequency of all biological endpoints studied were reduced following exposure to photoreactivating light parallel to the reduction in the frequencies of pyrimidine dimers (determined as endonuclease sensitive sites). However, there was not always an absolute quantitative relationship between the reduction in the frequency of pyrimidine dimers and the reduction in the biological effects. This probably reflects a fast fixation process for the biological effects prior to removal of the dimers by photoreactivation. (orig.)

  10. Use of induced mutations and biotechnology to tailor industrial crops for new crop rotations and quality improvement

    International Nuclear Information System (INIS)

    The induced mutation approach was employed to develop photo period insensitive mutants in jute (Corchorus olitorius), black hull in sunflower (Helianthus annuus) and double zero lines in Brassica napus. A late flowering mutant isolated in the M2 generation of jute variety TJ-40 was insensitive to the inductive short photo period for a significantly longer time than the parent. This trait of the mutant was confirmed by protracted sowing and exposure to short-days. In sunflower, black hulls are preferred by consumers. Black-hulled mutants with high seed yield were isolated in the variety 'Surya' having black and white zebra patches. Three of these mutants had significantly higher yield than the parent at two different locations. In Brassica napus, early flowering, high yielding mutants with double zero traits were developed. The fatty acid profile showed significant increase in the oleic acid content in these mutants. (author)

  11. Induced mutations of rice for short-culm selections in M2 generation

    International Nuclear Information System (INIS)

    Seeds of a leading rice variety Palkweng, japonica, were treated with X-rays and thermal neutrons to obtain mutations having short culm, earliness, resistance to lodging and blast disease, and a high yielding ability. 507 plants were selected for short-culm length; on the average they were also shorter in panicle length, lighter in weight of panicles, less in 100-grain weight and earlier in days to heading. There was no strict correlation between culm length and panicle length. Some plants had longer panicles in spite of a distinct reduction in culm length, but the number of panicles, weight of panicle and days to heading were positively correlated with culm length in the selected plants. The length of each internode from the base of the panicle down to the basal internode was gradually reduced. The lodging index was lower than that of the original variety, and culm length was positively correlated with lodging index. (author)

  12. Plant breeding for resistance to insect pests: Considerations about the use of induced mutations

    International Nuclear Information System (INIS)

    The Panel was intended to stimulate proposals on specific plant breeding objectives, for immediate and long term solution. Nine papers considered the host plant resistance to particular insect pests in a variety of cases. The desirability of achieving some measure of pest control via the development of disease-resistant mutants was discussed. In its conclusions, the Panel stressed the need to consider host plant resistance as one of the primary lines of defense in all pest management programmes. Consequently, resistance to insects was recommended to become an integral part of plant breeding programmes. Preference might need to be given to developing insect resistance in those crop plants for which practical control is lacking or where current methods of pest control present critical environmental hazards. The roles of the IAEA and FAO in such projects is outlined. Guidelines and recommendations on mutation breeding for resistance to insects are given in an appendix

  13. Induced mutation breeding in Cassava (Manihot esculenta Crantz) cultivar 'Bosom Nsia'

    International Nuclear Information System (INIS)

    Cassava is one of the most important staple food crops in the lowland tropics. In most cassava producing countries, it is mainly utilized for human consumption. Cassava leaves are a good source of protein and vitamins, and are used as food in Africa. In Ghana, 'Bosom Nsia' is one of the most widely grown cultivars probably because of its good cooking quality and fast maturation in six months. However, this cultivar is highly susceptible to cassava mosaic virus disease (CMV), hence the need to improve its resistance to the disease. Various in vitro techniques have been developed for cassava research, Klu and Lamptey reported irradiation doses of 25 and 30 Gy to be ideal for in vitro mutagenesis of cassava. These doses were applied to in vivo and in vitro mutation for breeding CMV resistance in the cultivar 'Bosom Nsia'. 6 refs

  14. [Malignant transformation of human fibroblasts by neutrons and by gamma radiation: Relationship to mutations induced

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    A brief overview if provided of selected reports presented at the International Symposium on Molecular Mechanisms of Radiation- and Chemical Carcinogen-Induced Cell Transformation held at Mackinac Island, Michigan on September 19-23, 1993.

  15. Isolation and propagation of mutations by in vitro culture. Part of a coordinated programme on improvement of vegetatively propagated crops and tree crops through radiation induced mutations

    International Nuclear Information System (INIS)

    Tuberous roots of two Dahlia cultivars were irradiated with 1000 - 2000 R of x-rays. Chlorophyll and flower colour mutations were scored on M1 plants and the subsequent vegetatively propagated generations. The project aimed at the development of experimental methods suitable for easy isolation of mutated tissue chimeras deriving from mutagen treatment. In comparing in vivo methods such as leaf bud cutting and root propagation with in vitro methods using explants from leaves and florets, the problems encountered by in vitro culture were so manifold, that this method is not considered to be at present of much promise. These experimental results should not discourage from developing and using in vitro culture methods for mutant isolation in other plant species, particularly those were in vivo adventitious bud techniques are not available. Besides the main result obtained, the following valuable observations were made: a) The genotype used for mutation induction is not only relevant for the number and the spectrum of mutations, but also size of chimerical sectors. b) Flower colour changes, which were investigated in some detail, revealed that pigments were lost as groups e.g. all buteins in one case and all cyanins plus pelargonins in another case. c) When using the leaf bud cutting method the greatest frequency of mutations was recovered from the axillary bud of the leaf, that is at the youngest primordial stage at the time of mutagen treatment

  16. Modulatory effects of Tabebuia impetiginosa (Lamiales, Bignoniaceae on doxorubicin-induced somatic mutation and recombination in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Neila C. de Sousa

    2009-01-01

    Full Text Available The wing Somatic Mutation and Recombination Test (SMART in D. melanogaster was used to study genotoxicity of the medicinal plant Tabebuia impetiginosa. Lapachol (naphthoquinone and β-lapachone (quinone are the two main chemical constituents of T. impetiginosa. These compounds have several biological properties. They induce apoptosis by generating oxygen-reactive species, thereby inhibiting topoisomerases (I and II or inducing other enzymes dependent on NAD(PH:quinone oxidoreductase 1, thus affecting cell cycle checkpoints. The SMART was used in the standard (ST version, which has normal levels of cytochrome P450 (CYP enzymes, to check the direct action of this compound, and in the high bioactivation (HB version, which has a high constitutive level of CYP enzymes, to check for indirect action in three different T. impetiginosa concentrations (10%, 20% or 40% w/w. It was observed that T. impetiginosa alone did not modify the spontaneous frequencies of mutant spots in either cross. The negative results observed prompted us to study this phytotherapeuticum in association with the reference mutagen doxorubicin (DXR. In co-treated series, T. impetiginosa was toxic in both crosses at higher concentration, whereas in the HB cross, it induced a considerable potentiating effect (from ~24.0 to ~95.0% on DXR genotoxity. Therefore, further research is needed to determine the possible risks associated with the exposure of living organisms to this complex mixture.

  17. Effects of gamma-irradiation-induced mutation on upland cotton pollen grains

    International Nuclear Information System (INIS)

    Despite the demonstrated value of gamma ray as a tool in plant mutation research, in the genetic plant species upland cotton (Gossypium hirsutum L.), such mutations have not been extensively studied. To investigate these questions, the upland cotton cultivar 'Sumian 22' pollen grains were irradiated by gamma rays (20Gy). The irradiation effects on pollen grains were tested considering the ultrastructure changes in the exine and interior walls of pollen grains, their germination rate, DNA polymorphism in the pollen grains, the actin filament in pollen tube, fertilization, and boll development after the pistils were pollinated by the pollen grains which were irradiation with γ-rays. As compared with the control, although the cell structures inside the pollen grain were destroyed, its exine and interior walls of the pollen grain were not etched. The amount and the density of pollen grain inclusions decreased and the size of the lacuna and starch granules increased. Pollen grain germination rate decreased by 37%. The number of pollen tubes in the style declined by 38%, but the growth speed of the tubes did not change. All of the pollen tubes reached the end of the style at 13-h after pollination. This result was consistent with that of the control. Also, the weight and the diameter of the ovary decreased and shortened. No evident change of the fecundation time of ovule was observed. The significant difference on DNA polymorphism was found between irradiation pollen grain and control after pollination by Simple sequence repeats (SSR) molecular marker. The actin filament of the apical domain in pollen tube was destabilized, and in the approximately apical domain, the actin cytoskeleton component disappeared. Various mutants were appeared in the M1 progenies. These results indicate that gamma rays can cause a series of biological changes in irradiated-pollen grains and their progenies of upland cotton. (author)

  18. The effects of heat shock induction expression of HSP70 on hprt genetic mutation induced by X-ray in lymphocytes

    International Nuclear Information System (INIS)

    Objective: To explore the effects of heat shock pretreatment on hprt genetic mutation induced by X-ray in lymphocytes. Method: The rat peripheral lymphocytes were cultured under 42 degree C and 5% CO2 for 90 min, then the cells were divided into 4 groups (control group, heat shock, radiation group, heat shock + radiation group), each group including 6 parallel samples. And each group was fractionated into 2 parts, one part with 6-TG (final concentration was 0.1 mmol/L) and the other without 6-TG. Each group of cells were irradiated by 0.5 Gy, 1.0 Gy, 1.5 Gy, 2.0 Gy, 2.5 Gy, 3.0 Gy X-ray and recovery cultured for 3 h, 6 h, 10 h, and then polykaryocytes test was used to detect the hprt mutation in the rat peripheral lymphocytes. Results: After exposure to different dose X-ray and recovery culture for 3 h, 6 h, 10 h, the mutation rate of hprt in heat shock + radiation group was significantly decreased (P<0.01) compared to radiation group. Conclusion: Heat shock pretreatment has protection effects on hprt mutation induced by X-ray. HSP70 has more obvious protection effects in low dose radiation than high dose radiation on hprt mutation induced by X-ray (P<0.01). There is negative correlation between protection effects and radiation doses. (authors)

  19. Anti-GD(2) with an FC point mutation reduces complement fixation and decreases antibody-induced allodynia.

    Science.gov (United States)

    Sorkin, Linda S; Otto, Mario; Baldwin, William M; Vail, Emily; Gillies, Stephen D; Handgretinger, Rupert; Barfield, Raymond C; Ming Yu, Hui; Yu, Alice L

    2010-04-01

    Monoclonal antibodies against GD(2) ganglioside, such as ch14.18, the human-mouse chimeric antibody, have been shown to be effective for the treatment of neuroblastoma. However, treatment is associated with generalized, relatively opiate-resistant pain. We investigated if a point mutation in ch14.18 antibody (hu14.18K332A) to limit complement-dependent cytotoxicity (CDC) would ameliorate the pain behavior, while preserving antibody-dependent cellular cytotoxicity (ADCC). In vitro, CDC and ADCC were measured using europium-TDA assay. In vivo, allodynia was evaluated by measuring thresholds to von Frey filaments applied to the hindpaws after injection of either ch14.18 or hu14.18K332 into wild type rats or rats with deficient complement factor 6. Other rats were pretreated with complement factor C5a receptor antagonist and tested following ch14.18 injection. The mutation reduces the antibody's ability to activate complement, while maintaining its ADCC capabilities. Injection of hu14.18K322 (1 or 3mg/kg) produced faster resolving allodynia than that engendered by ch14.18 (1mg/kg). Injection of ch14.18 (1mg/kg) into rats with C6 complement deficiency further reduced antibody-induced allodynia, while pre-treatment with complement factor C5a receptor antagonist completely abolished ch14.18-induced allodynia. These findings showed that mutant hu14.18 K322 elicited less allodynia than ch14.18 and that ch14.18-elicited allodynia is due to activation of the complement cascade: in part, to formation of membrane attack complex, but more importantly to release of complement factor C5a. Development of immunotherapeutic agents with decreased complement-dependent lysis while maintaining cellular cytotoxicity may offer treatment options with reduced adverse side effects, thereby allowing dose escalation of therapeutic antibodies. PMID:20171010

  20. Induced Mutations for Crop Improvement in Africa. Proceedings of a Regional Seminar on the Utilization of Induced Mutations for Crop Improvement in Africa Held in Conjunction with an Advisory Group on the Role and Limitations of Induced Mutations in Plant Improvement

    International Nuclear Information System (INIS)

    This seminar has been arranged with the intention to give plant breeders and plant geneticists from African countries an opportunity for refreshing and updating their knowledge in a technology that can be a useful supplement to plant breeding programmes. There are some who had been participating in training courses or study tours organized by FAO and IAEA, others who had been studying abroad under a fellowship programme. Others are holding a research contract or are counterparts in a technical assistance project. Again, there are others who know about the subject of mutation induction and the utilization of induced mutants in plant breeding only from textbooks or university courses. Besides updating knowledge and exchanging experiences, the seminar should be an occasion to discuss the need for and the efficiency of training programmes, and other forms of assistance

  1. Chemical inducible promoter used to obtain transgenic plants with a silent marker and organisms and cells and methods of using same for screening for mutations

    Science.gov (United States)

    Zuo, Jianru; Chua, Nam-Hai

    2007-06-12

    Disclosed is a chemically inducible promoter for transforming plants or plant cells with genes which are regulatable by adding the plants or cells to a medium containing an inducer or by removing them from such medium. The promoter is inducible by a glucocorticoid, estrogen or inducer not endogenous to plants. Such promoters may be used with any plant genes that can promote shoot regeneration and development to induce shoot formation in the presence of a glucocorticoid, estrogen or inducer. The promoter may be used with antibiotic or herbicide resistance genes or other genes which are regulatable by the presence or absence of a given inducer. Also presented are organisms or cells comprising a gene wherein the natural promoter of the gene is disrupted and the gene is placed under the control of a transgenic inducible promoter. These organisms and cells and their progeny are useful for screening for conditional gain of function and loss of function mutations.

  2. Mutation-induced loop opening and energetics for binding of tamiflu to influenza N8 neuraminidase.

    Science.gov (United States)

    Kar, Parimal; Knecht, Volker

    2012-05-31

    Tamiflu, also known as oseltamivir (OTV), binds to influenza A neuraminidase (H5N1) with very high affinity (0.32 nM). However, this inhibitor binds to other neuraminidases as well. In the present work, a systematic computational study is performed to investigate the mechanism underlying the binding of oseltamivir to N8 neuraminidase (NA) in "open" and "closed" conformations of the 150-loop through molecular dynamics simulations and the popular and well established molecular mechanics Poisson-Boltzmann (MM-PBSA) free energy calculation method. Whereas the closed conformation is stable for wild type N8, it transforms into the open conformation for the mutants Y252H, H274Y, and R292K, indicating that bound to oseltamivir these mutants are preferentially in the open conformation. Our calculations show that the binding of wild type oseltamivir to the closed conformation of N8 neuraminidase is energetically favored compared to the binding to the open conformation. We observe water mediated binding of oseltamivir to the N8 neuraminidase in both conformations which is not seen in the case of binding of the same drug to the H5N1 neuraminidase. The decomposition of the binding free energy reveals the mechanisms underlying the binding and changes in affinity due to mutations. Considering the mutant N8 variants in the open conformation adopted during the simulations, we observe a significant loss in the size of the total binding free energy for the N8(Y252H)-OTV, N8(H274Y)-OTV, and N8(R292K)-OTV complexes compared to N8(WT)-OTV, mainly due to the decrease in the size of the intermolecular electrostatic energy. For R292K, an unfavorable shift in the van der Waals interactions also contributes to the drug resistance. The mutations cause a significant expansion in the active site cavity, increasing its solvent accessible surface compared to the crystal structures of both the open and closed conformations. Our study underscores the need to consider dynamics in rationalizing the

  3. Generation of a human induced pluripotent stem cell line via CRISPR-Cas9 mediated integration of a site-specific heterozygous mutation in CHMP2B

    DEFF Research Database (Denmark)

    Zhang, Yu; Schmid, Benjamin; Nielsen, Troels T.;

    2016-01-01

    have generated an induced pluripotent stem cell (iPSC) line of a healthy individual and inserted the CHMP2B IVS5AS G-C gene mutation into one of the alleles, resulting in aberrant splicing. This human iPSC line provides an ideal model to study CHMP2B-dependent phenotypes of FTD3....

  4. Antimutagenic action of mammalian placental extracts on mutations induced in Escherichia coli by UV radiation, γ-rays and N-methyl-N'-nitro-N-nitrosoguanidine

    International Nuclear Information System (INIS)

    Mammalian placental extracts prepared from human, monkey, dog, rat and mouse had strong antimutagenic activities for reverse mutations induced in Escherichia coli B/r WP2 trp- by UV radiation, γ-rays and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). (orig.)

  5. Induced pluripotent stem cells (iPSCs) derived from a patient with frontotemporal dementia caused by a P301L 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 froma 57-year-old woman diagnosed with frontotemporal dementia. The diseaseis caused by a P301L mutation in microtubule-associated protein tau (MAPT). Induced pluripotent stem cells (iPSCs) were established by electroporation with episomal plasmids containing hOCT4, h...

  6. Subquivers of mutation-acyclic quivers are mutation-acyclic

    CERN Document Server

    Warkentin, Matthias

    2011-01-01

    Quiver mutation plays a crucial role in the definition of cluster algebras by Fomin and Zelevinsky. It induces an equivalence relation on the set of all quivers without loops and two-cycles. A quiver is called mutation-acyclic if it is mutation-equivalent to an acyclic quiver. The aim of this note is to show that full subquivers of mutation-acyclic quivers are mutation-acyclic.

  7. Stage specificity, dose response, and doubling dose for mouse minisatellite germ-line mutation induced by acute radiation

    OpenAIRE

    Dubrova, Yuri E.; Plumb, Mark; Brown, Julia; Fennelly, Jan; Bois, Philippe; Goodhead, Dudley; Jeffreys, Alec J

    1998-01-01

    Germ-line mutation induction at mouse minisatellite loci by acute irradiation with x-rays was studied at premeiotic and postmeiotic stages of spermatogenesis. An elevated paternal mutation rate was found after irradiation of premeiotic spermatogonia and stem cells, whereas the frequency of minisatellite mutation after postmeiotic irradiation of spermatids was similar to that in control litters. In contrast, paternal irradiation did not affect the maternal mutation rate. A linear dose–response...

  8. Improvement of pigeonpea for drought, disease and insect tolerance/resistance through induced mutations

    International Nuclear Information System (INIS)

    Pigeonpea (Cajanus cajan L. Millsp) is the second most important grain legume after cowpea (Vigna unguiculata L. Walp) in the semi-arid areas of Kenya. At the farm level, the grain yield of pigeonpea is lower than that of other grain legumes and cereals. The low grain yields are mainly attributed to the late-maturity of the local land-races which are prone to drought, insect attack and disease damage. Recently, a mutation breeding program was initiated to augment the conventional breeding approaches to alleviate some of these constraints. Three varieties, namely, Kat 60/8, Kat E31/4 and Kat 777, representing early, medium and late maturing groups were irradiated with three doses of gamma rays, namely 80-100 Gy, 110-125 Gy, and 140-150 Gy. Single plant progenies from the M2 and M3 generations of were screened and selected for tolerance to drought, tolerance/resistance to Fusarium wilt and insect tolerance in the field. Selections were advanced to M4 generation. In this paper, preliminary results of these studies reported. (author). 5 refs, 7 tabs

  9. Promising induced mutations in soybean varieties resistant to leaf spot fungi

    International Nuclear Information System (INIS)

    Irradiated seeds (20 krad of gamma rays) of three soybean varieties, Calland, Williams and Columbus, were sown (M1). The plants were kept free from disease and insect infection. Different morphological mutations were recorded visually and the seeds of the phenotypically normal plants of each variety were harvested and sown in bulk populations for the M2 generation. The plants were subjected to heavy artificial epiphytosis with two physiological isolates of Alternaria alternata and Drechslera australeinsis in separate fields. The seeds of the M3 and M4 selection progenies were sown in separate disease nurseries as line to row. Susceptible and abnormal plants were removed. Single plant yield components were determined for the selected mutants. The number of resistant mutants of the cultivars Calland, Williams and Columbus was 16, 21 and 18 (M3), which were screened to 12, 12 and 11 mutants (M4), respectively. Further screening was carried out and the data revealed that six, six and five mutants, respectively, showed resistance in the M5 generation. The mutants of M6 and M7 were grown in a randomized block design surrounded by the susceptible parents as a border. This border was inoculated with the two fungal isolates to serve as disease spreaders. The results obtained in M7 revealed that one and four mutants proved their superior yield and disease resistance over the parent cultivars Williams and Columbus, respectively. (author). 6 refs, 4 tabs

  10. Evolution of improved varieties of rapeseed/mustard through induced mutation

    International Nuclear Information System (INIS)

    Mutation breeding using gamma rays led to the development and release of two high yielding yellow sarson mustard mutant varieties, 'Safal' and 'Agrani' which are now commercially cultivated by the farmers of Bangladesh. Further studies with Brassica napus created a lot of variabilities in M2 with the selection of eight early maturing mutants which took 82 - 85 days to mature compared to 105 days by the original cultivar. The mutants bred true in M3 for earliness. A few indehiscent and semi-indehiscent mutants were also developed. Seed yields of the early mutants were about 2,000 kg per hectare which was comparable to the original cultivar. The mutants have 44-45% oil content in the seed compared to previously released varieties with 42-43% oil content. Mutants are moderately resistant to Alternaria blight in field condition. Other mutants segregated in M3 in different ratios and further selection was made. Evaluation of yellow sarson mutant BINA 2 along with other high yielding varieties in three saline zones of Bangladesh revealed that BINA 2 is more tolerant to salinity compared to existing high yielding varieties with an average yield of 1,888 kg followed by 1,758 kg by 'Agrani' and 1,699 kg by 'Safal', per ha. (author). 5 refs, 3 tabs

  11. Ribonuclease H2 mutations induce a cGAS/STING-dependent innate immune response.

    Science.gov (United States)

    Mackenzie, Karen J; Carroll, Paula; Lettice, Laura; Tarnauskaitė, Žygimantė; Reddy, Kaalak; Dix, Flora; Revuelta, Ailsa; Abbondati, Erika; Rigby, Rachel E; Rabe, Björn; Kilanowski, Fiona; Grimes, Graeme; Fluteau, Adeline; Devenney, Paul S; Hill, Robert E; Reijns, Martin Am; Jackson, Andrew P

    2016-04-15

    Aicardi-Goutières syndrome (AGS) provides a monogenic model of nucleic acid-mediated inflammation relevant to the pathogenesis of systemic autoimmunity. Mutations that impair ribonuclease (RNase) H2 enzyme function are the most frequent cause of this autoinflammatory disorder of childhood and are also associated with systemic lupus erythematosus. Reduced processing of eitherRNA:DNAhybrid or genome-embedded ribonucleotide substrates is thought to lead to activation of a yet undefined nucleic acid-sensing pathway. Here, we establishRnaseh2b(A174T/A174T)knock-in mice as a subclinical model of disease, identifying significant interferon-stimulated gene (ISG) transcript upregulation that recapitulates theISGsignature seen inAGSpatients. The inflammatory response is dependent on the nucleic acid sensor cyclicGMP-AMPsynthase (cGAS) and its adaptorSTINGand is associated with reduced cellular ribonucleotide excision repair activity and increasedDNAdamage. This suggests thatcGAS/STINGis a key nucleic acid-sensing pathway relevant toAGS, providing additional insight into disease pathogenesis relevant to the development of therapeutics for this childhood-onset interferonopathy and adult systemic autoimmune disorders. PMID:26903602

  12. A single amino acid mutation in SNAP-25 induces anxiety-related behavior in mouse.

    Directory of Open Access Journals (Sweden)

    Masakazu Kataoka

    Full Text Available Synaptosomal-associated protein of 25 kDa (SNAP-25 is a presynaptic protein essential for neurotransmitter release. Previously, we demonstrate that protein kinase C (PKC phosphorylates Ser(187 of SNAP-25, and enhances neurotransmitter release by recruiting secretory vesicles near to the plasma membrane. As PKC is abundant in the brain and SNAP-25 is essential for synaptic transmission, SNAP-25 phosphorylation is likely to play a crucial role in the central nervous system. We therefore generated a mutant mouse, substituting Ser(187 of SNAP-25 with Ala using "knock-in" technology. The most striking effect of the mutation was observed in their behavior. The homozygous mutant mice froze readily in response to environmental change, and showed strong anxiety-related behavior in general activity and light and dark preference tests. In addition, the mutant mice sometimes exhibited spontaneously occurring convulsive seizures. Microdialysis measurements revealed that serotonin and dopamine release were markedly reduced in amygdala. These results clearly indicate that PKC-dependent SNAP-25 phosphorylation plays a critical role in the regulation of emotional behavior as well as the suppression of epileptic seizures, and the lack of enhancement of monoamine release is one of the possible mechanisms underlying these defects.

  13. Development of drought tolerant tomato varieties through induced mutation in Cuba

    International Nuclear Information System (INIS)

    Having in mind the need to have tomato varieties growing under low water input conditions a tomato breeding program using nuclear techniques was started with the purpose of obtaining adequate yielding-potential cultivars under drought conditions. Seeds from INCA 9-1 variety were irradiated with 60Co gamma rays irradiated using of 300 Gy and 500 Gy. Starting from M2 generation, selection of high yield potential genotypes under low water supply conditions was made during 4 generations. Individual selection was done, taking into account the following criteria: healthy plants, determinate growth habit, yield per plant, fruit number per plant, average fruit weight, equatorial and polar fruit diameters were recorded in individually selected plants. The total soluble solids (Brix), acidity, dry matter and water content were evaluated in fruit of M5 generation. Different isoenzymatic systems, the protein concentration as well as the Random Amplified Polymorphism DNA (RAPD) were used in order to evaluate the genetic variability between the selected mutants and the donor variety. The most frequent variations observed in each generation were: plant cycle, fruit size, number, shape, colour and yield. It was possible to release two varieties of high yielding under low water input conditions. The tomato mutants Maybel and Mali are being used in tomato production for industrial purposes. These varieties are the firsts tomato varieties obtain from mutation induction in Cuba. (author)

  14. Use of Induced Mutations to Adopt Aromatic Rice to Low Country Conditions of Sri Lanka

    International Nuclear Information System (INIS)

    Two aromatic rice accessions, Au 27789 and IR Basmati were used in mutation breeding by subjecting 12,000 seeds of each variety to γ-ray doses of 200 or 300Gy from a 60Co source. Based on agronomic characteristics, 635 M2 plants were selected and grown as M3 progenies. Sixty plants were selected from non-irradiated parental varieties using the same criteria, and tested along with mutant plant progenies. Both doses of γ-rays were effective in creating genetic variability for agronomic characteristics, with high heritability values when M2 parent to M3 progeny regression-based heritability was compared with selection in non-irradiated control varieties. Three mutant lines with compact plant type, erect and larger flag leaf, compact panicles and acceptable quality recording the highest yield were tested in five locations over four seasons using two recommended cultivars as controls. The mutant line 22/3 with a medium level of aroma recorded more than 2.5 t/ha, higher than the average yield of rice (1.5 -2 t/ha) in low-country wet zone. It has a compact panicle and narrow leaf angle allowing denser planting, which may help further increase the yield. The mutant lines maintained superior kernel length, linear elongation ratio and expansion index, all of which are important characteristics of aromatic long grain rice. (author)

  15. The mutation reversion of induced waxy gene of rice in Indica

    International Nuclear Information System (INIS)

    Some induced waxy gene lines such as Nanhui 175wxR, Xianghui 288wxR, Minghui 86wxR, Shuhui 527wxR, Minghui 63wxR, II-32wxB, Longtepu wxB and D62wxB, which developed through irradiation induction of the parents of hybrid rice in indica, were selected as the materials, and the properties of endosperm of their inbred descendant brown rice were identified by visual estimation and by the method of 1% KI-I2 determination. It was the first time to discover the reversion of induced waxy mutants (waxy endosperm reversed to non-waxy ones) in rice, and the reversion frequency was between 0 to 6.34 x 10-5, with a average of 3.74 x 10-5 Genetic analysis indicated that induced waxy mutants reversion gene was dominant. Except for 1000-grain weight, no significant difference in other traits was found among the induced waxy mutants, the waxy mutants reversion and the wilds. A new core seed production and seed purity control techniques of the parents of waxy hybrid rice was also put forward in this paper. (authors)

  16. Flower colour mutations

    International Nuclear Information System (INIS)

    In the floriculture trade there is always a demand for new ornamental varieties. Flower colour is one of the most important components. Induced somatic mutation techniques using ionizing radiation and other mutagens have successfully produced many promising varieties in different ornamental plants by bringing about genetic changes. Induced mutation is a chance process. It is not known what flower colour change is likely to occur after mutagen treatment. Attempts are being made to induce a direct mutation for the flower colour of ornamental plants. For a better understanding of the exact mechanisms involved in the origin and evolution of somatic flower colour mutations at the molecular level, much attention has been paid to comparative analyses of the original cultivars and their induced mutants. Efforts are being made to identify the flower pigments and to prepare a colour chart which will be helpful in inducing the desired novelties in ornamental plants using induced genetic manipulation. 8 refs, 3 figs

  17. Combining Single Strand Oligodeoxynucleotides and CRISPR/Cas9 to Correct Gene Mutations in β-Thalassemia-induced Pluripotent Stem Cells.

    Science.gov (United States)

    Niu, Xiaohua; He, Wenyin; Song, Bing; Ou, Zhanhui; Fan, Di; Chen, Yuchang; Fan, Yong; Sun, Xiaofang

    2016-08-01

    β-Thalassemia (β-Thal) is one of the most common genetic diseases in the world. The generation of patient-specific β-Thal-induced pluripotent stem cells (iPSCs), correction of the disease-causing mutations in those cells, and then differentiation into hematopoietic stem cells offers a new therapeutic strategy for this disease. Here, we designed a CRISPR/Cas9 to specifically target the Homo sapiens hemoglobin β (HBB) gene CD41/42(-CTTT) mutation. We demonstrated that the combination of single strand oligodeoxynucleotides with CRISPR/Cas9 was capable of correcting the HBB gene CD41/42 mutation in β-Thal iPSCs. After applying a correction-specific PCR assay to purify the corrected clones followed by sequencing to confirm mutation correction, we verified that the purified clones retained full pluripotency and exhibited normal karyotyping. Additionally, whole-exome sequencing showed that the mutation load to the exomes was minimal after CRISPR/Cas9 targeting. Furthermore, the corrected iPSCs were selected for erythroblast differentiation and restored the expression of HBB protein compared with the parental iPSCs. This method provides an efficient and safe strategy to correct the HBB gene mutation in β-Thal iPSCs. PMID:27288406

  18. Genetic signatures from amplification profiles characterize DNA mutation in somatic and radiation-induced sports of chrysanthemum

    International Nuclear Information System (INIS)

    The chrysanthemum (Dendranthema grandiflora Tzvelev.) cultivars 'Dark Charm', 'Salmon Charm', 'Coral Charm' and 'Dark Bronze Charm' are either radiation-induced mutants or spontaneous sports of 'Charm' and constitute a family or series of plants that primarily differ in flower color. These cultivars, which were difficult to differentiate genetically by DNA amplification fingerprinting (DAF), were easily identified by using arbitrary signatures from amplification profiles (ASAP). Genomic DNA was first amplified with three standard octamer arbitrary primers, all of which produced monomorphic profiles. Products from each of these DNA fingerprints were subsequently reamplified using four minihairpin decamer primers. The 12 primer combinations produced signatures containing approximately 37% polymorphic character loci, which were used to estimate genetic relationships between cultivars. Forty-six (32%) unique amplification products were associated with individual cultivars. The number of ASAP polymorphisms detected provided an estimate of the mutation rate in the mutant cultivars, ranging from 0.03% to 1.6% of nucleotide changes within an average of 18 kb of arbitrary amplified DAF sequence. The ASAP technique permits the clear genetic identification of somatic mutants and radiation-induced sports that are genetically highly homogeneous and should facilitate marker assisted breeding and protection of plant breeders rights of varieties or cultivars

  19. Development of seedless fruits mutants in citrus including tangerine (C. reticulata) and pummelo (C. grandis) through induced mutations and biotechnology

    International Nuclear Information System (INIS)

    The development of seedless fruit mutants in citrus, including Tangerine (C. reticulata) and Pummelo (C. grandis), through induced mutation and biotechnology was studied at the Gamma Irradiation Service and Nuclear Technology Center, Pichit and Phare Horticultural Research Center for 4 years (August 2000 to September 2004). The results showed successful induction of mutants with gamma irradiation using both chronic and acute procedures for pot plants, scions and in vitro plantlets of tangerine (Citrus reticulata var. Shogun and Sai Nam Puaeng) and pummelo (Citrus grandis viz. Kao Thong Dee). MS medium with 2 mgL-1 of BA was found to be the most suitable medium for shoot proliferation. The seedlings were sub-cultured at least 4 times, and then they were treated with acute and chronic irradiation. Shoot induction from M1V0 to M1V4 generation was performed in basic MS medium with 2 mgL-1 added BA. Rooting was induced in the M1V4 in halfstrength MS enriched with BA 2 mgL-1. Later, the shoots were excised and grafted on mature plants or the plantlets directly transferred in the field and later the fruits from mature trees were evaluated for seedlessness in M1V4 at Pichit and Phare Horticultural Research Center. (author)

  20. 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)

    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 60Co 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)

  1. Mutation breeding newsletter. No. 45

    International Nuclear Information System (INIS)

    This issue of the Mutation Breeding newsletter contains 39 articles dealing with radiation induced mutations and chemical mutagenesis techniques in plant breeding programs with the aims of improving crop productivity and disease resistance as well as exploring genetic variabilities

  2. Mutation breeding newsletter. No. 33

    International Nuclear Information System (INIS)

    This issue of the newsletter reports a number of research news and research abstracts on application of radiation induced mutation techniques to increase mutagenesis and mutation frequency in plant breeding projects

  3. Qualitative analysis of mouse specific-locus mutations: information on genetic organization, gene expression, and the chromosomal nature of induced lesions

    Energy Technology Data Exchange (ETDEWEB)

    Russell, L.B.

    1982-01-01

    Analysis of mouse specific-locus (SL) mutations at three loci has identified over 33 distinct complementation groups - most of which are probably overlapping deficiencies - and 13 to 14 new functional units. The complementation maps that have been generated for the d-se and c regions include numerous vital functions; however, some of the genes in these regions are non-vital. At such loci, hypomorphic mutants must represent intragenic alterations, and some viable nulls could conceivably be intragenic lesions also. Analysis of SL mutations has provided information on genetic expression. Homozygous deficiencies can be completely viable or can kill at any one of a range of developmental stages. Heterozygonus deficiencies of up to 6 cM or more in genetic length have been recovered and propagated. The time of death of homozygous and the degree of inviability of heterozygous deficiencies are related more to specific content of the missing segment than to its length. Combinations of deficiencies with x-autosome translocations that inactivate the homologous region in a mosaic fashion have shown that organismic lethals are not necessarily cell lethal. The spectrum of mutations induced depends on the nature of the mutagen and the type of germ cell exposed. Radiation of spermatogonia produces intragenic as well as null mutations. Spontaneous mutations have an admixture of types not present in populations of mutations induced in germ cells, and this raises doubts concerning the accuracy of doubling-dose calculations in genetic risk estimation. The analysis of SL mutations has yielded genetic tools for the construction of detailed gene-dosage series, cis-trans comparisons, the mapping of known genes and identification of new genes, genetic rescue of various types, and the identification and isolation of DNA sequences. (ERB)

  4. Qualitative analysis of mouse specific-locus mutations: information on genetic organization, gene expression, and the chromosomal nature of induced lesions

    International Nuclear Information System (INIS)

    Analysis of mouse specific-locus (SL) mutations at three loci has identified over 33 distinct complementation groups - most of which are probably overlapping deficiencies - and 13 to 14 new functional units. The complementation maps that have been generated for the d-se and c regions include numerous vital functions; however, some of the genes in these regions are non-vital. At such loci, hypomorphic mutants must represent intragenic alterations, and some viable nulls could conceivably be intragenic lesions also. Analysis of SL mutations has provided information on genetic expression. Homozygous deficiencies can be completely viable or can kill at any one of a range of developmental stages. Heterozygonus deficiencies of up to 6 cM or more in genetic length have been recovered and propagated. The time of death of homozygous and the degree of inviability of heterozygous deficiencies are related more to specific content of the missing segment than to its length. Combinations of deficiencies with x-autosome translocations that inactivate the homologous region in a mosaic fashion have shown that organismic lethals are not necessarily cell lethal. The spectrum of mutations induced depends on the nature of the mutagen and the type of germ cell exposed. Radiation of spermatogonia produces intragenic as well as null mutations. Spontaneous mutations have an admixture of types not present in populations of mutations induced in germ cells, and this raises doubts concerning the accuracy of doubling-dose calculations in genetic risk estimation. The analysis of SL mutations has yielded genetic tools for the construction of detailed gene-dosage series, cis-trans comparisons, the mapping of known genes and identification of new genes, genetic rescue of various types, and the identification and isolation of DNA sequences

  5. Induced mutation studies with Brachiaria brizantha Stapf. and some indica rice varieties from Ceylon

    International Nuclear Information System (INIS)

    Non-imbibed seeds of Brachiaria brizantha were irradiated with doses of 60Co gamma rays ranging from 7.5 to 75 kR and fresh stem cuttings containing three nodes were irradiated with doses ranging from 7.5 to 45 kR. Chromosome counts were made using the Carnoy method. There was no germination at 75 kR, and 18% germination at 60 kR with no survival of the seedlings. At the other doses germination and seedling survival decreased from 56% and 100% respectively for the control to 42% and 46% respectively at 45 kR. There were no chlorophyll mutants at 7.5 kR, while a few were observed among seedlings at the higher doses. In the stem cuttings establishment was poor and morphological variations were observed at all doses above 15 kR. A mutant of desirable plant type was obtained from the 45-kR seed treatment with an erect growth habit, reduced pubescence, short internodes, profuse tillering and rapid regrowth compared with the parent. Four indica rice varieties, H-4, H-8, H-7 and Pachchaiperumal 2462/11 (PP 2462/11), were subjected to gamma rays, neutrons and ethyl methane sulphonate (EMS) treatments. The LD50 level for gamma rays was 50 to 60 kR, for neutrons 1600 R and for EMS 0.4%. Germination and final plant stand in the M1 generation were affected only slightly by the neutron treatments, but were greatly reduced by EMS, and gamma irradiation above 35 kR. The final plant stand of the variety PP 2462/11 was most reduced by all the mutagens. In the M2 generation there was segregation for chlorophyll mutants, of the albina, chlorina, xantha, virescens and zebrina types. Other macro-mutations observed were for grain size and shape, plant height, flowering date and sterility. Grass clump types were found occasionally. (author)

  6. Improvement of pigenonpea and cowpea for drought, disease and insect pest tolerance through induced mutations

    International Nuclear Information System (INIS)

    Pigeonpea and cowpea are widely grown in the semi-arid and arid regions of Kenya by small scale farmers. The average yields are usually low due to insect pests, diseases and long growth duration of the local land races. Little success has been achieved through conventional breeding methods for tolerance to insect pests and diseases despite the development of high yielding and early maturing lines. Therefore, mutation induction was initiated to widen the genetic variability in the improved lines. Seeds of three promising pigeonpea cultivars KAT 60/8, KAT 777 and KAT E31/4 and of cowpea KAT 419, K80 and M66 were subjected to three doses of gamma rays; 80, 120 and 150 Gy for pigeonpea and 160, 200 and 250 Gy for cowpea. In M1 generation, doses of 150 Gy and 250 Gy reduced emergence by about 50% and increased seedling deformities in both crops. In M2 generation of KAT 60/8, high yielding mutants with oval shaped seeds (T1 P58) and branching (T3 P28) were identified. Two progenies of KAT 777 (T1 P7 and T1 P11) had small slender leaves. Selected plant progenies in M3, M4 and M5 generation gave some promising high yielding variants. Although, the difference in days to flower and maturity of mutant progenies and untreated bulk were small, some mutant progenies of KAT 777 and KAT 60/8 showed tolerance to Fusarium wilt. None of the progenies of KAT E31/4 gave better score for Cercospora leaf-spot compared to the check. (author). 2 refs, 4 tabs

  7. Use of induced mutations in beans and peas for resistance to rust

    International Nuclear Information System (INIS)

    Gamma rays and ethyl methane-sulphonate (EMS) were applied in a mutation induction programme for rust resistance in beans and peas. Bean and pea seeds were presoaked for 2 h before irradiation with 8, 10 and 12 krad. For chemical mutagen treatments, bean and pea seeds were presoaked for 8 h and treated with 0.5 and 1.5% EMS for 4 h. M2 seeds of beans and peas were planted in 1980. Resistant M2 plants were selected for their rust resistance and other morphological characters. Seeds of the selected M6 mutants were planted as the M7 generation in Kaluabia Province during the October 1985 growing season to study the stability of the characters. Seeds of each mutant were planted in four replicates with five rows each, each row containing 100 plants. Seed germination was reduced by gamma rays or EMS. Dwarf, malformed and abnormal plants were noticed. Some resistant M2 plants selected gave high grain yields. Some were different in morphological characters. In the M3 of selected plants, various other mutant characters appeared, such as varying heights of plants, early and late flowering, resistance to powdery mildew in peas, altered grain yield, thick stems, and different pod shapes and flower colour; these characters were still stable in the M7 generation. In the second phase of this project, other seeds of the same varieties of beans and peas were treated in 1980 with EMS in concentrations of 0.1 and 0.3% with the aim of studying the effects of these doses on the production of mutants that are resistant to rust. These treated seeds were planted during September 1980 (beans) and October 1980 (peas). No clear mutants were revealed in the M1-M4 generations. 3 refs, 3 tabs

  8. 'Anjitha'- A new okra variety through induced mutation in inter specific hybrids of Abelmoschus SPP

    International Nuclear Information System (INIS)

    Studies on inter specific hybrids of okra between A. esculentus (cultivated type) and A. manihot (wild type) revealed that no useful recombinants were obtained from the conventional combination breeding programme because of the strong linkage between yellow vein mosaic (YVM) resistant genes and wild character of A. manihot. The present study envisaged the breaking of undesirable linkage through gamma irradiation (10, 20, 30 and 40 kRad) of F1 seeds obtained by inter specific hybridization between A. esculentus var. Kiran and A. manihot and further evaluation and selection of high yielding YVM resistant types from the segregating generations till F6M6. The mutagenic effectiveness and efficiency increased with increasing doses of gamma rays. The mutated hybrids and the wild parent showed complete resistance to YVM disease incidence which was confirmed through grafting trials. In the segregating generations, the irradiated treatments were late flowering and had more number of leaves, flowers and fruits per plant. Average fruit weight was maximum in 20 kR while fruit yield was maximum in 40 kR due to larger number of fruits. A few high yielding disease resistant plants resembling the cultivated plants were obtained in 30kR which suggested that 30 kR could be the ideal irradiation dose in okra. Thirteen superior genotypes selected from F6M6 generation based on yield and YVM resistance were advanced to three Comparative Yield Trials (CYT). Culture AE18 out yielded the others in CYTs and Farm trials and was released as 'Anjitha' by the XXIII State Seed Sub Committee during 2006 for cultivation in Thiruvananthapuram District of Kerala. Anjitha is a high yielding variety having the fruit characters and quality of the cultivated parent A. esculentus var. Kiran combined with the YVM resistant character of the wild parent A. manihot. (author)

  9. Induced mutation and radiation sensitivity in vitro culture of soybean (Glycine Max L. Merrill)

    International Nuclear Information System (INIS)

    In our research, the seeds of J-357 soybean variety were irradiated with 50, 100, 200, 300 and 500 Gy of gamma rays. Callus and meristem cultures were established from the primary leaves and apical meristem of 5-day-old seeding from the irradiation seeds. The average callus fresh weight formed at the cultures were determined on the 30th day and GR50 dose which reduces the callus fresh weight at the rate 50% in accordance with control was found as 250 Gy. The regenerated plants from meristem cultures were determined on the 28th day and LD50 dose which decreases the regenerated plant percentage at the 50% in accordance with control was found as 220 Gy. Cytological investigation was done at the callus and meristem cultures obtained from both irradiated seeds and explants. At the seed and explant irradiations, gamma radiation dose between the ranges 50 to 200 Gy and 5 to 25 Gy; respectively were used. Observations were done at mitotic anaphase in the samples taken from meristem and callus cultures. In anaphase, two types of cytological aberrations, bridge and fragments were determined. The regenerated plants were grown in the climate chamber and the seeds were taken from each M1 plant and chlorophyll mutants were determined in M2 generation. The radiosensitivity of the meristem cultures established by irradiated seeds from view of plant regenerations and plant number which is taken seed was evaluated by comparing with the results of meristem cultures established from the irradiated explant from the point of in vitro mutation studies

  10. Current status and research direction of induced mutation application to seed crops improvement in Vietnam

    International Nuclear Information System (INIS)

    In Vietnam, nuclear techniques and chemical mutagens have been applied in Vietnam since the 1970s in order to improve seed crops as rice, soybean, maize, groundnut, many mutant varieties were recognized as national varieties and some promising regional lines. Main direction and methods using in varietal improvement in Vietnam were exploitation of gene resources, using and genetic methods consisting of hybridization, mutation, gene transformation to create crops having high yield, good quality, tolerance to diseases and unsuitable climate conditions. Up to the year 2007, according to preliminary statistic, in Vietnam 50 mutant varieties were created (as IAEA database, having 43 mutant varieties created, Vietnam is being the ninth of mutant breeding' achievement record in the world), among of those seed crops occupied 47 varieties, rice occupied 32 varieties, soybean was 11, maize was 2 and peanut was 2. At AGI has created 17 rice mutant varieties, 11 mutant varieties of soybean were created and adopted by Ministry of Agriculture and RD as national and regional varieties, among of those occupied more than 50% of Vietnam soybean cultivated area thanks to their grown ability of three crops per year, broad adaptation, good tolerance to hot, cold temperature and good resistance to diseases.These varieties are preponderance in the Northern provinces and every year occupies about 20 - 40% of cultivated area. In present, some best mutant varieties has become one of the top 5 varieties for export and grown recently more than 300,000 ha per year in Southern Vietnam, about double the yield ( 10 tons/ha) of its parent VTL-3 (5 tons/ha). (author)

  11. Use of induced mutations to adopt aromatic rice to low country conditions of Sri Lanka

    International Nuclear Information System (INIS)

    Two aromatic rice accessions, Au 27789 and IR Basmati were used in mutation breeding by subjecting 12000 seeds of each variety to γ-ray doses of 200 or 300 Gy from a 60Co source. Based on agronomic characteristics, 635 M2 plants were selected and grown as M3 progenies. Sixty plants were selected from non-irradiated parental varieties using the same criteria, and tested along with mutant plant progenies. Both doses of γ-rays were effective in creating genetic variability for agronomic characteristics, with high heritability values when M2 parent to M3 progeny regression based heritabilities were compared with selection in non-irradiated control varieties. Three mutant lines with compact plant type, erect and larger flag leaf, compact panicles and acceptable quality recording the highest yield were tested in five locations over four seasons using two recommended cultivars as controls. The mutant line 22/3 with a medium level of aroma recorded more than 2.5 t/ha, higher than the average yield of rice (1.5 -2 t/ha) in low-country wet zone. It has a compact panicle and narrow leaf angle allowing denser planting, which may help further increase the yield. The mutant lines maintained superior kernel length, linear elongation ratio and expansion index, all of which are important characteristics of aromatic long grain rice. High quality aromatic Basmati rice is almost triple the price of rice produced from standard varieties, making their cultivation more profitable. Such grades fetch approximately two times the price of average-grade rice in international markets. Investigation and implementation of agronomic practices that enable the optimisation of the yield and quality of new mutant lines will help to increase profitability of rice cultivation in the marginal areas. Their further improvement may be possible through hybridisation among mutants

  12. Dysregulation of Hypoxia-Inducible Factor by Presenilin/ Gamma-Secretase Loss-of-Function Mutations

    OpenAIRE

    Kaufmann, M. R.; Barth, S; Konietzko, U; Wu, Bei; Egger, Sascha; Kunze, Reiner; Marti, Hugo H; Hick, Meike; Müller, Ulrike; Camenisch, G; Wenger, R H

    2013-01-01

    Presenilin (PSEN) 1 and 2 are the catalytic components of the Gamma-secretase complex, which cleaves a variety of proteins, including the amyloid precursor protein (APP). Proteolysis of APP leads to the formation of the APP intracellular domain (AICD) and amyloid Beta that is crucially involved in the pathogenesis of Alzheimer’s disease. Prolyl-4-hydroxylase-domain (PHD) proteins regulate the hypoxia inducible factors (HIFs), the master regulators of the hypoxic response.Wepreviously identifi...

  13. Imidacloprid and Thiamethoxam Induced Mutations in Internal Transcribed Spacer 2 (ITS2) of Anopheles stephensi

    OpenAIRE

    Bhinder, Preety; Chaudhry, Asha; Barna, Bhupinder; Kaur, Satvinderjeet

    2012-01-01

    The present article deals with the polymerase chain reaction (PCR)-based genotoxicity evaluation of neonicotinoid pesticides, imidacloprid and thiamethoxam, by using the genome of a mosquito Anopheles stephensi taken as an experimental model. After treatment of the second instar larvae with LC20 of the pesticides for 24 h, the induced nucleotide sequence variations in the internal transcribed spacer 2 (ITS2) of freshly hatched unfed control and treated individuals was studied from the sequenc...

  14. Opening Remarks by S Pandey [International Symposium on Induced Mutations in Plants, Vienna (Austria), 12-15 August 2008

    International Nuclear Information System (INIS)

    Crop plants form the major components of human diets, providing the required calories and nutrients to sustain life. With recent soaring of food prices, which is one of the immediate causes of the current food security crisis, the need to efficiently increase food availability through the production of high yielding crop varieties under the contrary effect of climate change and variability, plays a key role in ensuring food security. As such, holding this Symposium at this moment in time is a significant and blissful coincidence. An essential aspect of crop improvement is the utilization of the available genetic variation to produce new crop varieties. Induced mutations are a proven tool in creating a wealth of desirable genetic variability in plants, and its success in crop improvement abound. Currently the Joint Division's mutant varieties database registers over 2,700 mutant and mutant-derived varieties. Furthermore, some of these mutant varieties have contributed significantly to the livelihoods of farmers and their respective country's economy. For instance: - Diamant and Golden Promise being the progenitors of most of the cultivated barley varieties used in brewery industry in Scotland and most of Europe, contributing over 20 million US dollars per annum in additional income to farmers annually; - Durum wheat varieties used in the pasta industry in Italy arising from mutants account for tens of millions of US dollars in additional income to farmers per annum; - Grapefruit in the US with Rio Star mutant accounting for 75% of the US grapefruit industry; - The mutant pear variety Gold Nijesseiki in Japan contributes 30 million US dollars in additional income to farmers annually; - The rice mutant variety Zhefu 802 yield 10.6 million ha in China, giving a yield increase of 10.5% between 1980 and 1995. This translates into providing food to an extra two million people per year; and - In Vietnam, where rice export is one of the main national revenue sources, eight

  15. Deletion mutations of bacteriophage

    International Nuclear Information System (INIS)

    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.)

  16. Genetic redundancy between SPT23 and MGA2: regulators of Ty-induced mutations and Ty1 transcription in Saccharomyces cerevisiae.

    OpenAIRE

    S. Zhang; Burkett, T J; Yamashita, I; Garfinkel, D J

    1997-01-01

    SPT23 was isolated as a dosage-dependent suppressor of Ty-induced mutations in Saccharomyces cerevisiae. SPT23 shows considerable sequence homology with MGA2, a gene identified as a dosage-dependent suppressor of a snf2-imposed block on STA1 transcription in S. cerevisiae var. diastaticus. Although single mutations in either of these genes have only modest effects on cell growth, spt23 mga2 double mutants are inviable. Unlike SPT23, multicopy expression of a truncated form of MGA2 suppresses ...

  17. Generation of a human induced pluripotent stem cell line via CRISPR-Cas9 mediated integration of a site-specific homozygous mutation in CHMP2B

    DEFF Research Database (Denmark)

    Zhang, Yu; Schmid, Benjamin; Nielsen, Troels T.;

    2016-01-01

    Frontotemporal dementia (FTD) is an early onset neurodegenerative disease. Mutations in several genes cause familial FTD and one of them is charged multivesicular body protein 2B (CHMP2B) on chromosome 3 (FTD3), a component of the endosomal sorting complex required for transport III (ESCRT-III). ...... have generated an induced pluripotent stem cell (iPSC) line of a healthy individual and inserted the CHMP2B IVS5AS G-C gene mutation into both alleles, resulting in aberrant splicing. This human iPSC line provides an ideal model to study CHMP2B-dependent phenotypes of FTD3....

  18. Translesion DNA polymerases Pol , Pol , Pol , Pol and Rev1 are not essential for repeat-induced point mutation in Neurospora crassa

    Indian Academy of Sciences (India)

    Ranjan Tamuli; C Ravindran; Durgadas P Kasbekar

    2006-12-01

    Pol , Pol , Pol , Pol and Rev1 are specialized DNA polymerases that are able to synthesize DNA across a damaged template. DNA synthesis by such translesion polymerases can be mutagenic due to the miscoding nature of most damaged nucleotides. In fact, many mutational and hypermutational processes in systems ranging from yeast to mammals have been traced to the activity of such polymerases. We show however, that the translesion polymerases are dispensable for repeat-induced point mutation (RIP) in Neurospora crassa. Additionally, we demonstrate that the upr-1 gene, which encodes the catalytic subunit of Pol , is a highly polymorphic locus in Neurospora.

  19. Hypersensitivity of A8344G MERRF mutated cybrid cells to staurosporine-induced cell death is mediated by calcium-dependent activation of calpains.

    Science.gov (United States)

    Rommelaere, Guillaume; Michel, Sébastien; Malaisse, Jérémy; Charlier, Sophie; Arnould, Thierry; Renard, Patricia

    2012-01-01

    Mutations in the mitochondrial DNA can lead to the development of mitochondrial diseases such as Myoclonic Epilepsy with Ragged Red Fibers (MERRF) or Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like episodes (MELAS). We first show that human 143B-derived cybrid cells harboring either the A8344G (MERRF) or the A3243G (MELAS) mutation, are more prone to undergo apoptosis then their wild-type counterpart, when challenged with various apoptotic inducers such as staurosporine, etoposide and TRAIL. In addition, investigating the mechanisms underlying A8344G cybrid cells hypersensitivity to staurosporine-induced cell death, we found that staurosporine treatment activates caspases independently of cytochrome c release in both wild-type and mutated cells. Caspases are activated, at least partly, through the activation of calcium-dependent calpain proteases, a pathway that is more strongly activated in mutated cybrid cells than in wild-type cells exposed to staurosporine. These results suggest that calcium homeostasis perturbation induced by mitochondrial dysfunction could predispose cells to apoptosis, a process that could take part into the progressive cell degeneration observed in MERRF syndrome, and more generally in mitochondrial diseases. PMID:22037425

  20. 'Abasin-95', a new oilseed rape cultivar developed through induced mutations

    International Nuclear Information System (INIS)

    Brassica oilseeds are the second most important source of vegetable oil in Pakistan. Due to the low priority attached to these to these crops in the past, no systematic breeding work was undertaken to develop improved varieties of rapeseed/mustard, resulting in a narrow genetic base of these crops. At the Nuclear Institute for Food and Agriculture (NIFA), gamma radiation was used to induce genetic variability in traits of economic importance thus diversifying the genetic base of indigenous/exotic cultivars of Brassica oilseeds