Induced mutations for human welfare through agriculture

International Nuclear Information System (INIS)

Patil, S.A.

2009-01-01

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

Radiation-induced mutations and plant breeding

International Nuclear Information System (INIS)

Naqvi, S.H.M.

1985-01-01

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

Induced mutations - a tool in plant research

International Nuclear Information System (INIS)

1981-01-01

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

Induced mutations for crop improvement- the generation next

International Nuclear Information System (INIS)

Bhatia, C.R.

2000-01-01

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Induced Mutations in Thai Rice

International Nuclear Information System (INIS)

Klakhaeng, Kanchana

2014-01-01

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

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

International Nuclear Information System (INIS)

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

2006-01-01

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

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

International Nuclear Information System (INIS)

Kato, T.; Nakano, E.

1981-01-01

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

Improvement of basic food crops in Africa through plant breeding, including the use of induced mutations. Proceedings of a final research co-ordination meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

The Co-ordinated Research Programme (CRP) on Improvement of Basic Food Crops in Africa Through Plant Breeding, Including the Use of Induced Mutations, funded by the Italian Government, was initiated in 1989 in the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The primary objective of this CRP was to breed improved varieties of stable food crops of Africa with the main emphasis on the indigenous species and their local cultivars. The fourth and final Research Co-ordination meeting under the CRP was held in Naples, Italy from 30 October - 3 November 1995. This publication includes the reports, conclusions and recommendations made by the participants. We hope that it will be of value to researchers, students and policy makers alike in their endeavour to promote plant breeding and increase food productions in Africa. Refs, figs, tabs.

Improvement of basic food crops in Africa through plant breeding, including the use of induced mutations. Proceedings of a final research co-ordination meeting

International Nuclear Information System (INIS)

1997-07-01

The Co-ordinated Research Programme (CRP) on Improvement of Basic Food Crops in Africa Through Plant Breeding, Including the Use of Induced Mutations, funded by the Italian Government, was initiated in 1989 in the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The primary objective of this CRP was to breed improved varieties of stable food crops of Africa with the main emphasis on the indigenous species and their local cultivars. The fourth and final Research Co-ordination meeting under the CRP was held in Naples, Italy from 30 October - 3 November 1995. This publication includes the reports, conclusions and recommendations made by the participants. We hope that it will be of value to researchers, students and policy makers alike in their endeavour to promote plant breeding and increase food productions in Africa. Refs, figs, tabs

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-12-01

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

Alkylating agent (MNU)-induced mutation in space environment

Science.gov (United States)

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

2001-01-01

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

Mutation induced with ion beam irradiation in rose

Energy Technology Data Exchange (ETDEWEB)

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

2003-05-01

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

Mutation Breeding Newsletter. No. 37

International Nuclear Information System (INIS)

1991-01-01

This newsletter contains a brief account of FAO/IAEA meetings held in 1990 on plant breeding involving the use of induced mutations. It also features a list of commercially available plant cultivars produced by such techniques. Refs and tabs

Induced mutation in tropical fruit trees

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-05-15

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

Induced mutation in tropical fruit trees

International Nuclear Information System (INIS)

2009-05-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-15

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

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

International Nuclear Information System (INIS)

Kusaba, Makoto

2007-01-01

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

Induced skeletal mutations

International Nuclear Information System (INIS)

Selby, P.B.

1979-01-01

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

Molecular analysis of carbon ion-induced mutations in Arabidopsis thaliana

International Nuclear Information System (INIS)

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

1998-01-01

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

ENU-induced phenovariance in mice: inferences from 587 mutations

Directory of Open Access Journals (Sweden)

Arnold Carrie N

2012-10-01

Full Text Available Abstract Background We present a compendium of N-ethyl-N-nitrosourea (ENU-induced mouse mutations, identified in our laboratory over a period of 10 years either on the basis of phenotype or whole genome and/or whole exome sequencing, and archived in the Mutagenetix database. Our purpose is threefold: 1 to formally describe many point mutations, including those that were not previously disclosed in peer-reviewed publications; 2 to assess the characteristics of these mutations; and 3 to estimate the likelihood that a missense mutation induced by ENU will create a detectable phenotype. Findings In the context of an ENU mutagenesis program for C57BL/6J mice, a total of 185 phenotypes were tracked to mutations in 129 genes. In addition, 402 incidental mutations were identified and predicted to affect 390 genes. As previously reported, ENU shows strand asymmetry in its induction of mutations, particularly favoring T to A rather than A to T in the sense strand of coding regions and splice junctions. Some amino acid substitutions are far more likely to be damaging than others, and some are far more likely to be observed. Indeed, from among a total of 494 non-synonymous coding mutations, ENU was observed to create only 114 of the 182 possible amino acid substitutions that single base changes can achieve. Based on differences in overt null allele frequencies observed in phenotypic vs. non-phenotypic mutation sets, we infer that ENU-induced missense mutations create detectable phenotype only about 1 in 4.7 times. While the remaining mutations may not be functionally neutral, they are, on average, beneath the limits of detection of the phenotypic assays we applied. Conclusions Collectively, these mutations add to our understanding of the chemical specificity of ENU, the types of amino acid substitutions it creates, and its efficiency in causing phenovariance. Our data support the validity of computational algorithms for the prediction of damage caused by

Advances and prospects for induced mutation breeding in Helongjiang Province

International Nuclear Information System (INIS)

Sun Guangzu

1995-12-01

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

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

International Nuclear Information System (INIS)

Zhou Xin; Wang Zhenhua; Zhang Hong

2012-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

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

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

International Nuclear Information System (INIS)

Levy, A.; Ashri, A.

1978-01-01

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

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

International Nuclear Information System (INIS)

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

1984-01-01

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

Induced mutations for resistance to leaf rust in wheat

International Nuclear Information System (INIS)

Borojevic, K.

1983-01-01

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

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

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...

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

International Nuclear Information System (INIS)

Abrahamson, S.; Wolff, S.

1976-01-01

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

Application of DNA based marker mutations for improvement of cereals and other sexually reproduced crop plants. Proceedings of a final research co-ordination meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

The Co-ordinated Research Programme (CRP) on the Application of DNA Based Marker Mutations for Improvement of Cereals and Other Sexually Reproduced Crop Plants represents the first of three CRPs dealing with the application of molecular markers to mutations and plant breeding and was implemented between 1992 and 1996. A second companion CRP entitled Use of Novel DNA Fingerprinting Techniques for the Detection and Characterization of Genetic Variation in Vegetatively Propagated Crops devoted to the application of molecular markers in vegetatively propagated crops species was implemented between 1993 and 1997. One positive consequence of these two CRPs has been the implementation of a third CRP entitled Radioactively Labeled DNA Probes for Crop Improvement, which began in 1995 and aims to provide enabling technologies, in the form of probes and primers, to laboratories in developing countries. The rapid development of molecular marker technologies has also resulted in a dramatic increase in request from developing Member States for technical co-operation projects utilizing molecular markers to improve local varieties for biotic and abiotic stresses and other traits of relevance. With the intensified use of induced mutations in genetic studies, it will be important to continue the important work of understanding induced mutations at the molecular level. Evidence of the progress made in implementing molecular marker technologies in laboratories around the world is presented in this publication, which contains the results presented by the participants at the fourth and final Research Co-ordination Meeting of the CRP held in Vienna, 4-8 November 1996. The FAO and IAEA wish to express their sincere appreciation to the participants of the meeting for their work during the project period resulting in the summary and scientific reports presented in this publication. Refs, figs, tabs.

Application of DNA based marker mutations for improvement of cereals and other sexually reproduced crop plants. Proceedings of a final research co-ordination meeting

International Nuclear Information System (INIS)

1998-03-01

The Co-ordinated Research Programme (CRP) on the Application of DNA Based Marker Mutations for Improvement of Cereals and Other Sexually Reproduced Crop Plants represents the first of three CRPs dealing with the application of molecular markers to mutations and plant breeding and was implemented between 1992 and 1996. A second companion CRP entitled Use of Novel DNA Fingerprinting Techniques for the Detection and Characterization of Genetic Variation in Vegetatively Propagated Crops devoted to the application of molecular markers in vegetatively propagated crops species was implemented between 1993 and 1997. One positive consequence of these two CRPs has been the implementation of a third CRP entitled Radioactively Labeled DNA Probes for Crop Improvement, which began in 1995 and aims to provide enabling technologies, in the form of probes and primers, to laboratories in developing countries. The rapid development of molecular marker technologies has also resulted in a dramatic increase in request from developing Member States for technical co-operation projects utilizing molecular markers to improve local varieties for biotic and abiotic stresses and other traits of relevance. With the intensified use of induced mutations in genetic studies, it will be important to continue the important work of understanding induced mutations at the molecular level. Evidence of the progress made in implementing molecular marker technologies in laboratories around the world is presented in this publication, which contains the results presented by the participants at the fourth and final Research Co-ordination Meeting of the CRP held in Vienna, 4-8 November 1996. The FAO and IAEA wish to express their sincere appreciation to the participants of the meeting for their work during the project period resulting in the summary and scientific reports presented in this publication

Use of induced mutations for potato improvement

International Nuclear Information System (INIS)

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

1975-01-01

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

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

International Nuclear Information System (INIS)

Stoilov, M.; Daskaloff, S.

1976-01-01

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

Radiation-induced dominant skeletal mutations in mice

International Nuclear Information System (INIS)

Selby, P.B.

1979-01-01

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

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

International Nuclear Information System (INIS)

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

2007-01-01

Complete text of publication follows. Objective: Densely ionizing (high LET) radiation can increase the relative biological effectiveness of cell and tissue. Astronauts in the space exploration have the potential exposure of chronic low-dose radiations in the field of low-flux galactic cosmic rays (GCR) and the subsequent biological effects have become one of the major concerns of space science. Furthermore, Heavy ions also are used new radiation therapy owing increased lethal effectiveness of high LET radiation. During radiation therapy, normal tissues also are exposed to ionizing radiation. Radiation can induce genomic mutation and instability in descendants of irradiated cells. Induction of genomic instability can represent one of the initiating steps leading to malignant transformation. Higher frequencies of mutation can be expected to provide higher rates of carcinogenicity with human exposure. Therefore, the study of radiation induced genomic mutation and instability is relevant to the estimates of the risk of secondary malignancies associated with radiation therapy and the carcinogenic effects of space environmental radiation. The hypoxanthine-guanine phosphoribosyltransferase (hprt) locus has been the most commonly used as a target gene for mutation detection studies. In this study, we investigated the generation expression dependence of mutation induction on HPRT locus in CHO cells irradiated with carbon ions. Methods: Chinese hamster ovary (CHO) cells were irradiated with graded doses of carbon ions (290MeV/u, LET:13kev/um) accelerated with Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences(NIRS). The survival effect of cells plated immediately after irradiation was measured with cell colony formation assay. After irradiation, cells were continues reseeding and cultures for lone-term proliferation. Cell samples were collected at 6, 12, 18, 24, 30, 37 and 44 days post irradiation. Mutation induction of cell

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Development of breeding materials in rice by use of induced mutation

International Nuclear Information System (INIS)

Amano, Etsuo

1988-01-01

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

Radiation-induced cell mutations as a function of dose rate

International Nuclear Information System (INIS)

Kiefer, J.

1987-01-01

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

Use of induced mutations for cotton breeding in India

International Nuclear Information System (INIS)

Raut, R.N.

1980-01-01

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

Genetic improvement of 'NPq' rice with induced mutations

International Nuclear Information System (INIS)

Ram, Mahabal

1974-01-01

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

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

International Nuclear Information System (INIS)

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

1988-01-01

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

Irradiation-induced mutation experiments with eiploid and tetraploid tomato plants

International Nuclear Information System (INIS)

Boda, J.

1979-01-01

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

Genetic improvement of Sesamun indicum through induced mutations

International Nuclear Information System (INIS)

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

2001-01-01

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

p53 gene mutation hotspots in skin cancer and ultraviolet induced mutation

International Nuclear Information System (INIS)

Ikehata, Hironobu

1998-01-01

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

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

International Nuclear Information System (INIS)

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

2003-01-01

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

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)

Datta, SK.

2001-01-01

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

Induced mutations in citrus

International Nuclear Information System (INIS)

Spiegel-Roy, P.; Vardi, Aliza

1990-01-01

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

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

International Nuclear Information System (INIS)

Gupta, M.N.

1980-01-01

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

Use of induced mutations for the improvement of grain legume production in Southeast Asia

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-07-01

The improvement of grain legume production encompasses numerous possible actions. Some of these include (1) the upgrading of the quality of seeds used by farmers, (2) insurance that effective symbiotic nitrogen fixation is carried out through the use of effective inoculants, and (3) the development of superior, high-yielding, pathogen-resistant new varieties of crop varieties through plant breeding. It is only the last of these topics which was considered in detail at the Sri Lanka seminar. This meeting was organized with the dual purpose of identifying breeding objectives in the grain legumes and also to suggest ways in which induced mutations may be used in attaining these objectives. The work of the meeting was systematized by considering the complex task of defining breeding objectives as follows: A. Plant architecture: Breeders put forth ideas as to what the most desirable features of plant morphology should be with respect to different crop species and for local conditions. B. Disease and pest resistance: Breeders spoke about the major pathogens and pests which affect specific grain legume crops grown in different countries at different times. The magnitude of the problem was also indicated along with the availability of genetic resources with which to breed against particular pests. C. Physiological characters: Such topics as photoperiodic sensitivity, seed viability, nitrogen fixation, maturity time and other characteristics were considered and the ways in which these factors affect production. Following these discussions, the group documented the breeding needs for the major grain legumes of the region. In this context the participants were asked to identify potential situations where the induced mutation approach to plant breeding would prove valuable. During the meeting, breeders from different countries, unknown to one another previously, who work towards almost identical objectives, established communication and even arranged to begin to exchange germ

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

Science.gov (United States)

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

1989-08-01

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

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

Science.gov (United States)

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

2004-02-01

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

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

International Nuclear Information System (INIS)

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

2003-01-01

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

Feeding the world with induced mutations and biotechnology

International Nuclear Information System (INIS)

Mohan Jain, S.

2002-01-01

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

Induced mutations and marker assisted breeding in soybean

Energy Technology Data Exchange (ETDEWEB)

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

2002-02-01

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

Utilization of induced mutations in improving legumes in Egypt

International Nuclear Information System (INIS)

Abo-Hegazi, A. M. T.

1993-01-01

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

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

International Nuclear Information System (INIS)

Sasaki, Mutsuo; Nakata, Noboru; Yasumuro, Yoshimasa

1982-01-01

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

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

International Nuclear Information System (INIS)

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

1993-01-01

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

Achievements and trends of using induced mutations in crop improvement

International Nuclear Information System (INIS)

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

2000-01-01

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

Genetic improvement of black gram using induced mutations

International Nuclear Information System (INIS)

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

2000-01-01

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

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

International Nuclear Information System (INIS)

1998-01-01

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

Radiation induced mutations in Phaseolus vulgaris L

International Nuclear Information System (INIS)

Al-Rubeai, M.A.F.

1982-01-01

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Cellular repair and its importance for UV-induced mutations

Energy Technology Data Exchange (ETDEWEB)

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

1975-01-01

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

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

Science.gov (United States)

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

2005-09-16

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

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

International Nuclear Information System (INIS)

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

1988-01-01

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

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

International Nuclear Information System (INIS)

Do Khac Thinh; Hung Phi Oanh; Nguyen Thi Cuc; Nguyen Ngoc Quynh

2001-01-01

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 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 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)

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)

Induced mutations for improvement of grain legume production II

International Nuclear Information System (INIS)

1982-02-01

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

Induced mutations of rust resistance genes in wheat

International Nuclear Information System (INIS)

McIntosh, R.A.

1983-01-01

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

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

International Nuclear Information System (INIS)

Traut, H.

1979-01-01

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

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)

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

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-08-01

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

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

International Nuclear Information System (INIS)

2003-08-01

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

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

International Nuclear Information System (INIS)

Barragan, Raul; Rubio, Santiago

1993-01-01

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

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.

Molecular analysis of radiation-induced mutations in vitro

International Nuclear Information System (INIS)

Kronenberg, A.

1996-01-01

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Current status and outlook perspectives of induced mutations for plant improvement

International Nuclear Information System (INIS)

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

2009-01-01

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

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

International Nuclear Information System (INIS)

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

1977-01-01

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

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

Science.gov (United States)

James, A P; Kilbey, B J

1977-10-01

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

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

Science.gov (United States)

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

2017-01-01

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

Gamma ray induced somatic mutations in rose

International Nuclear Information System (INIS)

Datta, S.K.

1989-01-01

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

Plant breeding: Induced mutation technology for crop improvement

International Nuclear Information System (INIS)

Novak, F.J.; Brunner, H.

1992-01-01

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

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

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

International Nuclear Information System (INIS)

Cornu, Andre

1978-01-01

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

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

International Nuclear Information System (INIS)

Klu, G. Y. P.

2000-01-01

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

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

International Nuclear Information System (INIS)

Abrahamson, S.

1981-02-01

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

Induced mutations in highly heterozygous vegetatively propagated grasses

International Nuclear Information System (INIS)

Powell, J.B.

1976-01-01

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

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

International Nuclear Information System (INIS)

Prakash, L.

1974-01-01

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

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

Science.gov (United States)

Prakash, L

1974-12-01

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

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

International Nuclear Information System (INIS)

Micke, A.; Maluszynski, M.; Donini, B.

1985-01-01

Since 1969 we have collected information on cultivated varieties of plants, developed by using induced mutations. Whenever we learn about a cultivar presumably derived from an induced mutant or from use of mutants in crosses. we mail a questionnaire to the breeder. The information gathered in this way is stored in our file on ''Mutant Varieties''. Excerpts are published regularly in the form of a list in the FAO/IAEA Mutation Breeding Newsletter. Our mutant variety list has repeatedly provided a basis for analyses on the value and prospects of mutation breeding

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

Energy Technology Data Exchange (ETDEWEB)

Micke, A; Maluszynski, M; Donini, B [Joint FAO/IAEA Division, Plant Breeding and Genetics Section, Vienna (Austria)

1985-05-01

Since 1969 we have collected information on cultivated varieties of plants, developed by using induced mutations. Whenever we learn about a cultivar presumably derived from an induced mutant or from use of mutants in crosses. we mail a questionnaire to the breeder. The information gathered in this way is stored in our file on ''Mutant Varieties''. Excerpts are published regularly in the form of a list in the FAO/IAEA Mutation Breeding Newsletter. Our mutant variety list has repeatedly provided a basis for analyses on the value and prospects of mutation breeding.

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

International Nuclear Information System (INIS)

Aleksandrova, M.V.; Lapidus, I.L.; Aleksandrov, I.D.; Karpovskij, A.L.

1996-01-01

The white locus in D.Melanogaster was selected as a target gene for the study of the mutational spectra of spontaneously arising and radiation-induced gene mutations in a whole organism. Analysis of 6 spontaneous and 73 γ-ray-induced white mutations by a combination of cytological, genetic and molecular techniques revealed that on the chromosomal and genetic levels all spontaneous mutations showed themselves to be point mutants. The share of such mutants among all heritable radiation-induced gene mutations is about 40%, whereas the rest ones are due to exchange breaks (8%) as well as multilocus, single-locus or partial-locus (intragenic) deletions (52%). The DNAs from 4 spontaneous and 17 γ-ray-induced point mutants were analysed by Southern blot-hybridization. The three spontaneous and 7 radiation mutants showed an altered DNA sequence at the left (distal) half of the white gene due to insertion or DNA rearrangement. The rest (58%) of the radiation-induced point mutations did not indicate any alternations in this part of the gene as detected by this technique and probes employed. 15 refs., 3 figs., 1 tab

Development of radiation-induced mutation techniques and functional genomics studies

International Nuclear Information System (INIS)

Kim, Dong Sub; Kang, Si Yong; Kim, Jin Baek

2012-01-01

This project has been performed to develop plant genetic resources using radiation (gamma-rays, ion-beam, space environments), to conduct functional genomics studies with mutant resources, and to develop new radiation plant breeding techniques using various radiation sources during 3 years. In the first section, we developed flower genetic resources, functional crop resources, and bio-industrial plant resources. In the second section, we cloned several mutated genes and studied mechanisms of gene expression and genetic diversity of mutations induced by gamma-rays. In the third section, we developed new plant breeding techniques using gamma-phytotron, heavy ion-beam, and space environments. Based on these results, a total of 8 cultivars containing Chrysanthemum, Hibiscus, kenaf, rice, and soybean were applied for plant variety protection (PVP) and a total of 4 cultivars were registered for PVP. Also, license agreement for the dwarf type Hibiscus mutant 'Ggoma' was conducted with Supro co. and the manufacturing technology for natural antioxidant pear-grape vinegar was transferred into Enzenic co. Also, 8 gene sequences, such as F3'H and LDOX genes associated with flower color in Chrysanthemum and EPSPS gene from Korean lawn grass, were registered in the database of National Center for Biotechnology Information (NCBI). In the future study, we will develop new radiation mutation breeding techniques through the mutation spectrum induced by various radiation sources, the studies for mechanism of the cellular response to radiation, and the comparative·structural·functional genomics studies for useful traits

Induced mutation in soybean (Glycine max L.) breeding

International Nuclear Information System (INIS)

Tulmann Neto, A.; Menten, J.O.M.; Ando, A.

1984-01-01

The induced mutation in soybean (Glycine max, L.) breeding is studied. Seed treatment with gamma-rays or methanesulfonic acid ethyl ester (EMs) is used in the following varieties: Parana, Santa Rosa, UFV-1, Foscarin 31 and IAC-8. The study to obtain resistance to the soybean bud blight virus and mutants resistant to rust was done. Early mutants are also researched. (M.A.C.) [pt

Where antibiotic resistance mutations meet quorum-sensing

Directory of Open Access Journals (Sweden)

Rok Krašovec

2014-06-01

Full Text Available We do not need to rehearse the grim story of the global rise of antibiotic resistant microbes. But what if it were possible to control the rate with which antibiotic resistance evolves by de novo mutation? It seems that some bacteria may already do exactly that: they modify the rate at which they mutate to antibiotic resistance dependent on their biological environment. In our recent study [Krašovec, et al. Nat. Commun. (2014, 5, 3742] we find that this modification depends on the density of the bacterial population and cell-cell interactions (rather than, for instance, the level of stress. Specifically, the wild-type strains of Escherichia coli we used will, in minimal glucose media, modify their rate of mutation to rifampicin resistance according to the density of wild-type cells. Intriguingly, the higher the density, the lower the mutation rate (Figure 1. Why this novel density-dependent ‘mutation rate plasticity’ (DD-MRP occurs is a question at several levels. Answers are currently fragmentary, but involve the quorum-sensing gene luxS and its role in the activated methyl cycle.

Induction of somatic mutations by low-dose X-rays: the challenge in recognizing radiation-induced events.

Science.gov (United States)

Nagashima, Haruki; Shiraishi, Kumiko; Ohkawa, Saori; Sakamoto, Yuki; Komatsu, Kenshi; Matsuura, Shinya; Tachibana, Akira; Tauchi, Hiroshi

2017-10-19

It is difficult to distinguish radiation-induced events from spontaneous events during induction of stochastic effects, especially in the case of low-dose or low-dose-rate exposures. By using a hypersensitive system for detecting somatic mutations at the HPRT1 locus, we investigated the frequency and spectrum of mutations induced by low-dose X-rays. The mutant frequencies induced by doses of >0.15 Gy were statistically significant when compared with the spontaneous frequency, and a clear dose dependency was also observed for mutant frequencies at doses of >0.15 Gy. In contrast, mutant frequencies at doses of 0.2 Gy. Our observations suggest that there could be a critical dose for mutation induction at between 0.1 Gy and 0.2 Gy, where mutagenic events are induced by multiple DNA double-strand breaks (DSBs). These observations also suggest that low-dose radiation delivered at doses of <0.1 Gy may not result in DSB-induced mutations but may enhance spontaneous mutagenesis events. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Genetic and molecular analyses of UV radiation-induced mutations in the fem-3 gene of Caenorhabditis elegans

Energy Technology Data Exchange (ETDEWEB)

Hartman, P S; De Wilde, D; Dwarakanath, V N [Texas Christian Univ., Fort Worth, TX (United States). Dept. of Biology

1995-06-01

The utility of a new target gene (fem-3) is described for investigating the molecular nature of mutagenesis in the nematode Caenorhabditis elegans. As a principal attribute, this system allows for the selection, maintenance and molecular analysis of any type of mutation that disrupts the gene, including deletions. In this study, 86 mutant strains were isolated, of which 79 proved to have mutations in fem-3. Twenty of these originally tested as homozygous inviable. Homozygous inviability was expected, as Stewart and coworkers had previously observed that, unlike in other organisms, most UV radiation-induced mutations in C. elegans are chromosomal rearrangements of deficiencies (Mutat. Res 249, 37-54, 1991). However, additional data, including Southern blot analyses on 49 of the strains, indicated that most of the UV radiation-induced fem-3 mutations were not deficiencies, as originally inferred from their homozygous inviability. Instead, the lethals were most likely ``coincident mutations`` in linked, essential genes that were concomitantly induced. As such, they were lost owing to genetic recombination during stock maintenance. As in mammalian cells, yeast and bacteria, the frequency of coincident mutations was much higher than would be predicted by chance. (Author).

A radiation-induced compact type Granny Smith apple mutation

International Nuclear Information System (INIS)

Hurter, N.; Van Tonder, M.J.

1982-01-01

More successful compact mutant clones of Granny Smith apple are being sought, for those that have so far arisen naturally have undesirable tree and fruit charateristics. For this purpose, gamma rays from a Cobalt-60 radiation unit were used to induce mutant types artificially. One compact mutation of Granny Smith was produced via re-irradiation

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.

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Analysis of chlorophyll mutations induced by γ-rays in barley (hordeum vulgare)

International Nuclear Information System (INIS)

Wang Cailian; Shen Mei; Xu Gang; Zhao Kongnan; Chen Qiufang

1991-06-01

Thirty varieties of dormant barley seeds were irradiated with 137 Cs γ-rays. Dose-effect relations of chlorophyll mutation frequency in M 2 seedling and differences resulting from cultured types or radiosensitive types were investigated. Experimental results show that the relations between chlorophyll mutation frequency and doses can be fitted by a linear regression equation Y = A + BX. According to analysis of covariance, there is no considerable difference in various cultured types, but the difference of five different radiosensitive types is remarkable. The sensitive and intermediate types need much lower doses than other types to induce maximum chlorophyll mutation

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

International Nuclear Information System (INIS)

Yao Suyan; Zhang Chaoyang; Dai Lianlian; Gao Changwen

1991-01-01

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 60 Co γ irradiation is 5.59%. The effect of dominant lethal mutation is higher than that of the aneuploidy

Induced mutations for improvement of grain legume production

International Nuclear Information System (INIS)

1980-11-01

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

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

International Nuclear Information System (INIS)

Beckman, C.; Roy, R.M.; Sproule, A.

1982-01-01

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)

Mutations induced by the action of metal ions in Pisum

Energy Technology Data Exchange (ETDEWEB)

von Rosen, G

1957-01-01

Simple metal ions may induce both radiomimetic effects and genuine gene mutations of the same type which occurs from ionizing radiation and from treatment with some chemical agencies as e.g., mustard gas. The main material during the experiments has been species of Pisum. The biochemical principle which lies behind these reactions is the complex-forming ability among those reactive bivalent metal elements. The author assumes that interruptions of the chelate formation in the cell synthesis form the real background to the observed activity of the metal ions. The possible role in the evolution of the plant- and animal kingdom and the probable value for plant-breeding of the mutation activity observed are suggested. A new field for mutation experiments may here be opened and the results must hitherto be judged as interesting and promising. 13 references, 7 figures, 4 tables.

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

International Nuclear Information System (INIS)

Zambrano A, F.; Guzman R, J.; Paredes G, L.; Delfin L, A.

1997-01-01

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)

Mutation direction by irradiation in rice

International Nuclear Information System (INIS)

Wang Cailian; Chen Qiufang; Jin Wei; Lu Yimei

2001-01-01

The mutation directions of rice were studied. The results indicated that the mutation directions of rice induced by 14 C were invert correlation to their genetic backgrounds of tested rice varieties, i.e. early mature and short stem varieties produced later mature and higher stem mutation; late mature and high stem varieties produced earlier mature and shorter stem mutation; the varieties of middle maturity and height produced both direction mutations of earlier and later maturity or shorter and higher stem. The mutation directions induced by 14 C were also related to treated doses and stages. Frequency of earlier maturity mutation by protons treatment were higher than those induced by other mutagens. Frequency of later maturity by γ-rays were higher than those induced by other mutagens. Frequency of short stem mutation by synchronous irradiation (soft X-rays) were higher than those induced by other mutagens. Frequency of beneficial mutation induced by proton treatment were higher than those induced by γ-rays

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)

Kimura, Hiroshi; Kato, Takesi.

1992-01-01

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)

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

International Nuclear Information System (INIS)

Kitahashi, Tsukasa; Takahashi, Mami; Yamada, Yutaka

2008-01-01

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

Induced mutations for quantitative traits in rice

International Nuclear Information System (INIS)

Chakrabarti, B.N.

1974-01-01

The characteristics and frequency of micro-mutations induced in quantitative traits by radiation treatment and the extent of heterozygotic effects of different recessive chlorophyll-mutant-genes on quantitative trait has been presented. Mutagenic treatments increased the variance for quantitative traits in all cases although the magnitude of increase varied depending on the treatment and the selection procedure adopted. The overall superiority of the chlorophyll-mutant heterozygotes over the corresponding wild homozygotes, as noted in consecutive two seasons, was not observed when these were grown at a high level of nitrogen fertiliser. (author)

A population genetic analysis of the potential for a crude oil spill to induce heritable mutations and impact natural populations

Energy Technology Data Exchange (ETDEWEB)

Cronin, M.A. [LGL Alaska Research Associates Inc., Anchorage, AK (United States); Bickham, J.W. [Texas A and M University, College Station, TX (United States). Dept. of Wildlife and Fisheries Sciences; LGL Ecological Genetics Inc., Bryan, TX (United States)

1998-07-01

The primary environmental impact following an oil spill typically is acute toxicity to fish and wildlife. However, multigenerational effects through toxicant-induced heritable mutations might also occur. Some polycyclic aromatic hydrocarbon (PAH) components of crude oil are potentially mutagenic, although specific components and doses that induce mutations are poorly known. We applied population genetics concepts to assess the extent of mortality and the persistence of deleterious heritable mutations resulting from exposure to potential mutagens, such as crude oil. If lethal mutations are induced, the population will experience some mortality, but the mutations are quickly removed or reduced to low frequency by natural selection. This occurs within one or a few generations when mutations are dominant or partially recessive. Totally recessive alleles persist in low frequency for many generations, but result in relatively little impact on the population, depending on the number of mutated loci. We also applied population genetics concepts to assess the potential for heritable mutations induced by the Exxon Valdez oil spill in Prince William Sound, Alaska, to affect pink salmon populations. We stress that breeding units (e.g., streams with distinct spawning populations of salmon) must be considered individually to assess heritable genetic effects. For several streams impacted by the oil spill, there is inconsistency between observed egg mortality and that expected if lethal heritable mutations had been induced by exposure to crude oil. Observed mortality was either higher or lower than expected depending on the spawning population, year, and cohort considered. Any potential subtle effect of lethal mutations induced by the Exxon Valdez oil spill is overridden by natural environmental variation among spawning areas. We discuss the need to focus on population-level effects in toxicological assessments because fish and wildlife management focuses on populations, not

Frequency and spectrum of mutations induced by gamma irradiation in single, double and triple dwarf wheats

International Nuclear Information System (INIS)

Dhonukshe, B.L.

1981-01-01

Induced mutation studies were carried with three dwarf wheat varieties viz., ''Sonalika'', ''Chhoti Lerma'' and ''Hira'', considered to be single, double and trible dwarfs, respectively. Gamma-rays were used as a source of irradiation. Frequency of chlorophyll mutations were comparatively low and the spectrum was narrow. Chlorophyll mutations were altogether absent in the variety ''Sonalika''. A very wide spectrum of viable mutations affecting stem, leaf, ear growth habit, maturity and fertility characteristics was observed in the M 2 . The cumulative frequency of all the mutants together was quite high, which varied with the varieties. There were varietal differences in the composition and width of the spectrum induced by gamma-rays. The dwarf mutants having desirable leaf and spike characters were isolated in all the three varieties. (author)

Effect of 60-Hz magnetic fields on ultraviolet light-induced mutation and mitotic recombination in Saccharomyces cerevisiae.

Science.gov (United States)

Ager, D D; Radul, J A

1992-12-01

The purpose of this study was to examine the effect of extremely low frequency (ELF) magnetic fields on the induction of genetic damage. In general, mutational studies involving ELF magnetic fields have proven negative. However, studies examining sister-chromatid exchange and chromosome aberrations have yielded conflicting results. In this study, we have examined whether 60-Hz magnetic fields are capable of inducing mutation or mitotic recombination in the yeast Saccharomyces cerevisiae. In addition we determined whether magnetic fields were capable of altering the genetic response of S. cerevisiae to UV (254 nm). We measured the frequencies of induced mutation, gene conversion and reciprocal mitotic crossing-over for exposures to magnetic fields alone (1 mT) or in combination with various UV exposures (2-50 J/m2). These experiments were performed using a repair-proficient strain (RAD+), as well as a strain of yeast (rad3) which is incapable of excising UV-induced thymine dimers. Magnetic field exposures did not induce mutation, gene conversion or reciprocal mitotic crossing-over in either of these strains, nor did the fields influence the frequencies of UV-induced genetic events.

Effect of tumor promoters on ultraviolet light-induced mutation and mitotic recombination in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Kunz, B.A.; Hannan, M.A.; Haynes, R.H.

1980-01-01

Recently, it has been suggested that mitotic recombination is involved in tumor promotion. On this basis, one might expect tumor promoters to be recombinagenic. D7 is a diploid strain of yeast in which both mutation and mitotic recombination can be measured. We have used this strain to assay the known tumor promoters, iodacetate, anthralin, and 12-0-tetradecanoylphorbol-13-acetate, and the cocarcinogen, catechol, for mutagenicity, recombinagenicity, and the ability to enhance ultraviolet light (UV)-induced genetic events. In the absence of preirradiation with UV, iodoacetate was found to be recombinagenic whereas catechol was mutagenic; however, in both cases, the effects were small. Iodoacetate, anthralin, and catechol potentiated UV-induced mitotic crossing-over, aberrant colony formation, and mutation, while catechol also increased UV-induced gene conversion. We were unable to detect any mutagenic or recombinagenic effect of 12-0-tetradecanoyl-phorbol-13-acetate in either whole cells or spheroplasts. Our results do not indicate any consistent correlation between tumor-promoting activity and the ability of an agent to induce mitotic recombination in yeast. However, the ability to potentiate UV-induced mutation and mitotic recombination may reflect the cocarcinogenic activity of certain promoters

HPRT gene locus mutation in peripheral blood lymphocytes induced by internal exposure to radionuclides

Energy Technology Data Exchange (ETDEWEB)

Jingyong, Zhao; Yongzhong, Xu; Tao, Zhao; Fengmei, Cui; Liuyi, Wang; Qinhua, Lao [Suzhou Univ., Suzhou (China). Radiation Medicine Department

2001-07-01

HPRT gene locus mutation in peripheral blood lymphocytes induced by internal exposure to radionuclides was performed and the relationships between mutation frequency and dose were studied. Rats were injected intravenously with radionuclides, the blood was sampled at different time after injection; HPRT gene locus mutation frequency (GMF) were examined by methods of multi-nucleus cell and Brdurd assay, working out the Dose-response function. GMF rose with the increase of dose and dose-rates and were clearly interrelated. The HPRT gene locus mutation is very sensitive to radiation and may be used as a biological dosimeter.

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-06-25

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

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Effect of AC magnetic fields on ultraviolet light-induced mutation and mitotic recombination in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Ager, D.D.; Radul, J.A.

1994-01-01

The ability of 60-Hz magnetic fields to induce genetic damage in Saccharomyces cerevisiae was studied. The frequencies of induced mutation, gene conversion, and reciprocal mitotic crossing over were measured for exposures to 1-millitesla magnetic fields alone or in combination with various preliminary exposures to 254-nm ultraviolet light at intensities of 2-50 J/m 2 . These experiments were performed using a repair-proficient strain as well as a strain incapable of excising ultraviolet-induced thymine dimers. Magnetic field exposures did not induce mutation, gene conversion, or reciprocal mitotic crossing over in either of these strains, nor did the fields influence the frequencies of ultraviolet-induced genetic events. 32 refs., 4 tabs

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

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

International Nuclear Information System (INIS)

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

1977-01-01

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

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

International Nuclear Information System (INIS)

Xu Honglan; Cao Yi; Duan Zhikai; Wu Qiqing; Chen Ying; Zhang Shuxian

1998-12-01

The somatic induction frequencies of mutation at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus induced by 60 Co 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 V 79 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(+S 9 ) treatments. The dose ranges for the two mutagens were compared when they induced the same mutation frequencies. In V 79 /HGPRT assay system, when the mutation frequencies were 5∼35 mutants/10 6 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/10 5 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 60 Co γ-rays

Analysis of mutations in the human HPRT gene induced by accelerated heavy-ion irradiation

International Nuclear Information System (INIS)

Kagawa, Yasuhiro; Yatagai, Fumio; Hanaoka, Fumio; Suzuki, Masao; Kase, Youko; Kobayashi, Akiko; Hirano, Masahiko; Kato, Takesi; Watanabe, Masami.

1995-01-01

Multiplex PCR analysis of HPRT(-) mutations in human embryo (HE) cells induced by 230 keV/μm carbon-ion irradiation showed no large deletion around the exon regions of the locus gene in contrast to the irradiations at different LETs. To identify these mutations, the sequence alterations in a cDNA of hprt gene were determined for 18 mutant clones in this study. Missing of exon 6 was the most frequent mutational event (10 clones), and missing of both exons 6 and 8 was next most frequent event (6 clones), then base substitutions (2 clones). These characteristics were not seen in a similar analysis of spontaneous mutations, which showed base substitution (5 clones), frameshift (2 clones), missing of both exons 2 and 3 (2 clones), and a single unidentified clone. Direct sequencing and restriction enzyme digestion of the genomic DNA of the mutants which showed missing of exons 6 and 8 in the cDNA, supports the possibility that they were induced by aberrant mRNA splicing. (author)

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Induced mutations in castor

International Nuclear Information System (INIS)

Ganesan, K.; Javad Hussain, H.S.; Vindhiyavarman, P.

2001-01-01

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 M 3 generation were bred true in subsequent generations up to M 8 generation. Critical evaluation of the mutants in yield evaluation trials is in progress

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

International Nuclear Information System (INIS)

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

1994-01-01

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

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

International Nuclear Information System (INIS)

1977-01-01

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

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

International Nuclear Information System (INIS)

Machida, I.; Nakai, S.

1980-01-01

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.)

[Mutants of the yeast Saccharomyces cerevisiae characterized by enhanced induced mutagenesis. III. Effect of the him mutation on the effectiveness and specificity of UF-induced mutagenesis].

Science.gov (United States)

Ivanov, E L; Koval'tsova, S V; Korolev, V G

1987-09-01

We have studied the influence of him1-1, him2-1, him3-1 and himX mutations on induction frequency and specificity of UV-induced adenine-dependent mutations in the yeast Saccharomyces cerevisiae. Him mutations do not render haploid cells more sensitive to the lethal action of UV-light; however, in him strains adenine-dependent mutations (ade1, ade2) were induced more frequently (1.5--2-fold), as compared to the HIM strain. An analysis of the molecular nature of ade2 mutants revealed that him1-1, him2-1 and himX mutations increase specifically the yield of transitions (AT----GC and GC----AT), whereas in the him3-1 strain the yield of transversions was enhanced as well. We suggest him mutations analysed to affect specific repair pathway for mismatch correction.

On the effect of hyperaldosteronism-inducing mutations in Na/K pumps.

Science.gov (United States)

Meyer, Dylan J; Gatto, Craig; Artigas, Pablo

2017-11-06

Primary aldosteronism, a condition in which too much aldosterone is produced and that leads to hypertension, is often initiated by an aldosterone-producing adenoma within the zona glomerulosa of the adrenal cortex. Somatic mutations of ATP1A1, encoding the Na/K pump α1 subunit, have been found in these adenomas. It has been proposed that a passive inward current transported by several of these mutant pumps is a "gain-of-function" activity that produces membrane depolarization and concomitant increases in aldosterone production. Here, we investigate whether the inward current through mutant Na/K pumps is large enough to induce depolarization of the cells that harbor them. We first investigate inward currents induced by these mutations in Xenopus Na/K pumps expressed in Xenopus oocytes and find that these inward currents are similar in amplitude to wild-type outward Na/K pump currents. Subsequently, we perform a detailed functional evaluation of the human Na/K pump mutants L104R, delF100-L104, V332G, and EETA963S expressed in Xenopus oocytes. By combining two-electrode voltage clamp with [ 3 H]ouabain binding, we measure the turnover rate of these inward currents and compare it to the turnover rate for outward current through wild-type pumps. We find that the turnover rate of the inward current through two of these mutants (EETA963S and L104R) is too small to induce significant cell depolarization. Electrophysiological characterization of another hyperaldosteronism-inducing mutation, G99R, reveals the absence of inward currents under many different conditions, including in the presence of the regulator FXYD1 as well as with mammalian ionic concentrations and body temperatures. Instead, we observe robust outward currents, but with significantly reduced affinities for intracellular Na + and extracellular K + Collectively, our results point to loss-of-function as the common mechanism for the hyperaldosteronism induced by these Na/K pump mutants. © 2017 Meyer et al.

Improvement of basic food crops in Africa through plant breeding, including the use of induced mutations. Report of the third research co-ordination meeting of FAO/IAEA/ITALY co-ordinated research programme. Working material

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-01

A Co-ordinated Research Programme, on ``Improvement of basic food corps in Africa through plant breeding including the use of induced mutations``, funded by the Italian Governmnet, was initiated in the Joint Division of the Food and Agriculture Organization and International Atomic Energy Agency, Vienna. The primary objective of this CRP was to breed improved varieties of staple food crops of Africa with main emphasis on the indigenous species and local cultivars. The Third Research Co-ordination Meeting (RCM) under the FAO/IAEA/ITALY Co-ordinated Research Programme was held in Nairobi, Kenya, 20-24 September 1993 in which 24 persons participated and 18 scientific reports were presented. These included reports from 10 Research Contract holders from Africa, 3 Technical Contract holders from Italy and the update on the backstopping of research carried out at the IAEA Laboratories, Seibersdorf. The reports, and conclusions and recommendations made by the participants are presented in this publication. Refs, figs, tabs.

Improvement of basic food crops in Africa through plant breeding, including the use of induced mutations. Report of the third research co-ordination meeting of FAO/IAEA/ITALY co-ordinated research programme. Working material

International Nuclear Information System (INIS)

1997-01-01

A Co-ordinated Research Programme, on ''Improvement of basic food corps in Africa through plant breeding including the use of induced mutations'', funded by the Italian Governmnet, was initiated in the Joint Division of the Food and Agriculture Organization and International Atomic Energy Agency, Vienna. The primary objective of this CRP was to breed improved varieties of staple food crops of Africa with main emphasis on the indigenous species and local cultivars. The Third Research Co-ordination Meeting (RCM) under the FAO/IAEA/ITALY Co-ordinated Research Programme was held in Nairobi, Kenya, 20-24 September 1993 in which 24 persons participated and 18 scientific reports were presented. These included reports from 10 Research Contract holders from Africa, 3 Technical Contract holders from Italy and the update on the backstopping of research carried out at the IAEA Laboratories, Seibersdorf. The reports, and conclusions and recommendations made by the participants are presented in this publication. Refs, figs, tabs

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

International Nuclear Information System (INIS)

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

2001-01-01

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

Molecular cytogenetics of radiation-induced gene mutations in Drosophila melanogaster

International Nuclear Information System (INIS)

Aleksandrov, I.D.; Aleksandrova, M.V.; Lapidus, I.L.; Karpovskij, A.L.

1996-01-01

The classical paradigm of spatially unrelated lesions for gene mutations and chromosomal exchange breakpoints induced by ionizing radiations in eukaryotic cells was re-examined in the experiments on the mapping of gamma-ray- or neutron-induced breakpoints in and outside of white (w) and vestigial (vg) genes of Drosophila melanogaster using the in situ hybridization of the large fragments of the genes under study with the polythene chromosomes of the relevant mutants. The results for the random sample of 60 inversion and translocation breakpoints analysed to date have shown that (i) 50% of them are mapped as the hot spots within big introns of both the genes, and (ii) 21 of 60 breaks (35%) are located outside of genes. It is important to note that 26% (16/60) of the breakpoints analysed are flanked by the deletions, the sizes of which vary from the quarter to a whole of the gene. It was found that the deletions flank both the inversion and translocation breakpoints and arise more often after action of neutrons than photons. An unexpectedly high frequency of the multiple-damaged w and vg mutants that have the gene/point mutation and additional, but separate, chromosome exchange (the so-called double- or triple-site mutants) has shown that the genetic danger of ionizing radiation is higher than usually accepted on the base of single gene/point mutation assessments. 11 refs., 3 figs

Specialists meeting on LMFBR flow induced vibrations. Summary report

International Nuclear Information System (INIS)

1977-12-01

A Specialists' Meeting on LMFBR Flow-Induced Vibrations was held at ANL in the United States which was sponsored by the International Atomic Energy Agency (IAEA) on the recommendations of the International Working Group on Fast Reactors (IWGFR). It was attended by participants from France, the Federal Republic of Germany, Italy, Japan, Netherlands, the United Kingdom, the Union of Soviet Socialist Republics, the United States and the IAEA. The purpose of the meeting was to provide, for the first time, a common forum for the exchange of information on flow-induced vibration programs of the member countries. As this was a first meeting, information was sought in the broad areas of: 1. Design Criteria and Problem Areas in LMFBR Design; 2. Current Design Procedures; and 3. Ongoing Research. A session was devoted to each of the above topics wherein papers were presented and discussed followed by open discussions on the session topic. The objective of the open discussions was to identify, from a review of specific reactor designs, (a) flow induced vibration problem areas (expected and observed) and their potential for occurrence; (b) failure modes and associated design criteria; (c) specific components that are susceptible to flow induced vibration; and (d) probable excitation mechanisms. It was aimed to assess the current state-of-the-art in designing to avoid flow induced vibration with consideration of licensing requirements; to evaluate existing methods of analysis, testing, and surveillance, along with their limitations and to identify areas requiring research and review ongoing research programmes relative to these research needs

Specialists meeting on LMFBR flow induced vibrations. Summary report

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-12-01

A Specialists' Meeting on LMFBR Flow-Induced Vibrations was held at ANL in the United States which was sponsored by the International Atomic Energy Agency (IAEA) on the recommendations of the International Working Group on Fast Reactors (IWGFR). It was attended by participants from France, the Federal Republic of Germany, Italy, Japan, Netherlands, the United Kingdom, the Union of Soviet Socialist Republics, the United States and the IAEA. The purpose of the meeting was to provide, for the first time, a common forum for the exchange of information on flow-induced vibration programs of the member countries. As this was a first meeting, information was sought in the broad areas of: 1. Design Criteria and Problem Areas in LMFBR Design; 2. Current Design Procedures; and 3. Ongoing Research. A session was devoted to each of the above topics wherein papers were presented and discussed followed by open discussions on the session topic. The objective of the open discussions was to identify, from a review of specific reactor designs, (a) flow induced vibration problem areas (expected and observed) and their potential for occurrence; (b) failure modes and associated design criteria; (c) specific components that are susceptible to flow induced vibration; and (d) probable excitation mechanisms. It was aimed to assess the current state-of-the-art in designing to avoid flow induced vibration with consideration of licensing requirements; to evaluate existing methods of analysis, testing, and surveillance, along with their limitations and to identify areas requiring research and review ongoing research programmes relative to these research needs.

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-04-01

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

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

International Nuclear Information System (INIS)

Halliday, Gary M.

2005-01-01

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

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

International Nuclear Information System (INIS)

Maeda, Munetoshi; Kobayashi, Katsumi; Matsumoto, Hideki; Usami, Noriko; Tomiya, Masanori

2013-01-01

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 µm 2 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)

Neutron-induced mutation experiments and total radiation-induced genetic damage in entire genomes of Drosophila melanogaster. Final report, November 1, 1967-August 31, 1980

International Nuclear Information System (INIS)

Abrahamson, S.

1981-02-01

Neutron-induced mutation experiments with Drosophila oogonia were conducted at the University of Wisconsin, with irradiations being carried out at the RARAF facility at Brookhaven National Laboratory. X-linked recessive lethals and specific locus mutations were studied. Using the α value of the weighted linear regression equation for lethal data, RBE's relative to X-rays were calculated for the energies of neutrons studied. They are: 15 MeV to 2.0; 6 MeV to 2.9; 2 MeV to 3.2; .66 MeV to 4.0; .43 MeV to 4.8. The dose/frequency response curves for lethal data of all neutron energies studied was suggestive of a quadratic component. All data best fit a linear hypothesis, however. Control data for specific locus mutations was used to estimate the number of loci on the X-chromosome which are capable of mutating to lethals. Neutron-induced data for specific locus mutation was inconclusive due to the high error inherent in the frequencies obtained

Insight on Mutation-Induced Resistance from Molecular Dynamics Simulations of the Native and Mutated CSF-1R and KIT.

Directory of Open Access Journals (Sweden)

Priscila Da Silva Figueiredo Celestino Gomes

Full Text Available The receptors tyrosine kinases (RTKs for the colony stimulating factor-1, CSF-1R, and for the stem cell factor, SCFR or KIT, are important mediators of signal transduction. The abnormal function of these receptors, promoted by gain-of-function mutations, leads to their constitutive activation, associated with cancer or other proliferative diseases. A secondary effect of the mutations is the alteration of receptors' sensitivity to tyrosine kinase inhibitors, compromising effectiveness of these molecules in clinical treatment. In particular, the mutation V560G in KIT increases its sensitivity to Imatinib, while the D816V in KIT, and D802V in CSF-1R, triggers resistance to the drug. We analyzed the Imatinib binding affinity to the native and mutated KIT (mutations V560G, S628N and D816V and CSF-1R (mutation D802V by using molecular dynamics simulations and energy calculations of Imatinib•target complexes. Further, we evaluated the sensitivity of the studied KIT receptors to Imatinib by measuring the inhibition of KIT phosphorylation. Our study showed that (i the binding free energy of Imatinib to the targets is highly correlated with their experimentally measured sensitivity; (ii the electrostatic interactions are a decisive factor affecting the binding energy; (iii the most deleterious impact to the Imatinib sensitivity is promoted by D802V (CSF-1R and D816V (KIT mutations; (iv the role of the juxtamembrane region, JMR, in the imatinib binding is accessory. These findings contribute to a better description of the mutation-induced effects alternating the targets sensitivity to Imatinib.

Radiation-induced germ-line mutations detected by a direct comparison of parents and children DNA sequences containing SNPs

International Nuclear Information System (INIS)

Morimyo, M.; Hongo, E.; Higashi, T.; Wu, J.; Matsumoto, I.; Okamoto, M.; Kawano, A.; Tsuji, S.

2003-01-01

Full text: Germ-line mutation is detected in mice but not in humans. To estimate genetic risk of humans, a new approach to extrapolate from animal data to humans or to directly detect radiation-induced mutations in man is expected. We have developed a new method to detect germ-line mutations by directly comparing DNA sequences of parents and children. The nucleotide sequences among mouse strains are almost identical except SNP markers that are detected at 1/1000 frequency. When gamma-irradiated male mice are mated with female mice, heterogeneous nucleotide sequences induced in children DNA are a candidate of mutation, whose assignment can be done by SNP analysis. This system can easily detect all types of mutations such as transition, transversion, frameshift and deletion induced by radiation and can be applied to humans having genetically heterogeneous nucleotide sequences and many SNP markers. C3H male mice of 8 weeks of gestation were irradiated with gamma rays of 3 and 1 Gy and after 3 weeks, they were mated with the same aged C57BL female mice. After 3 weeks breeding, DNA was extracted from parents and children mice. The nucleotide sequences of 150 STS markers containing 300-900 bp and SNPs of parents and children DNA were determined by a direct sequencing; amplification of STS markers by Taq DNA polymerase, purification of PCR products, and DNA sequencing with a dye-terminator method. At each radiation dose, a total amount of 5 Mb DNA sequences were examined to detect radiation-induced mutations. We could find 6 deletions in 3 Gy irradiated mice but not in 1 Gy and control mice. The mutation frequency was about 4.0 x 10 -7 /bp/ Gy or 1.6 x 10 -4 /locus/Gy, and suggested the non-linear increase of mutation rate with dose

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

International Nuclear Information System (INIS)

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

1979-01-01

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

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

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

Energy Technology Data Exchange (ETDEWEB)

Hu, C H [Taiwan Provincial Chung-Hsing University, Taichung, Taiwan (China); Wu, H P; Li, H W [Academia Sinica, Nankang, Taipei, Taiwan (China)

1970-03-01

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)

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

International Nuclear Information System (INIS)

Hu, C.H.; Wu, H.P.; Li, H.W.

1970-01-01

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)

Mutated genes as research tool

International Nuclear Information System (INIS)

1981-01-01

Green plants are the ultimate source of all resources required for man's life, his food, his clothes, and almost all his energy requirements. Primitive prehistoric man could live from the abundance of nature surrounding him. Man today, dominating nature in terms of numbers and exploiting its limited resources, cannot exist without employing his intelligence to direct natural evolution. Plant sciences, therefore, are not a matter of curiosity but an essential requirement. From such considerations, the IAEA and FAO jointly organized a symposium to assess the value of mutation research for various kinds of plant science, which directly or indirectly might contribute to sustaining and improving crop production. The benefit through developing better cultivars that plant breeders can derive from using the additional genetic resources resulting from mutation induction has been assessed before at other FAO/IAEA meetings (Rome 1964, Pullman 1969, Ban 1974, Ibadan 1978) and is also monitored in the Mutation Breeding Newsletter, published by IAEA twice a year. Several hundred plant cultivars which carry economically important characters because their genes have been altered by ionizing radiation or other mutagens, are grown by farmers and horticulturists in many parts of the world. But the benefit derived from such mutant varieties is without any doubt surpassed by the contribution which mutation research has made towards the advancement of genetics. For this reason, a major part of the papers and discussions at the symposium dealt with the role induced-mutation research played in providing insight into gene action and gene interaction, the organization of genes in plant chromosomes in view of homology and homoeology, the evolutionary role of gene duplication and polyploidy, the relevance of gene blocks, the possibilities for chromosome engineering, the functioning of cytroplasmic inheritance and the genetic dynamics of populations. In discussing the evolutionary role of

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

International Nuclear Information System (INIS)

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

1995-01-01

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

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

International Nuclear Information System (INIS)

Gao Yong; Zhang Weiguang

2004-01-01

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

Chemotherapy-induced amenorrhea in patients with breast cancer with a BRCA1 or BRCA2 mutation.

Science.gov (United States)

Valentini, Adriana; Finch, Amy; Lubinski, Jan; Byrski, Tomasz; Ghadirian, Parviz; Kim-Sing, Charmaine; Lynch, Henry T; Ainsworth, Peter J; Neuhausen, Susan L; Greenblatt, Ellen; Singer, Christian; Sun, Ping; Narod, Steven A

2013-11-01

To determine the likelihood of long-term amenorrhea after treatment with chemotherapy in women with breast cancer who carry a BRCA1 or BRCA2 mutation. We conducted a multicenter survey of 1,954 young women with a BRCA1 or BRCA2 mutation who were treated for breast cancer. We included premenopausal women who were diagnosed with invasive breast cancer between 26 and 47 years of age. We determined the age of onset of amenorrhea after breast cancer for women who were and were not treated with chemotherapy, alone or with tamoxifen. We considered chemotherapy-induced amenorrhea to have occurred when the patient experienced ≥ 2 years of amenorrhea, commencing within 2 years of initiating chemotherapy, with no resumption of menses. Of the 1,426 women who received chemotherapy, 35% experienced long-term amenorrhea. Of the 528 women who did not receive chemotherapy, 5.3% developed long-term amenorrhea. The probabilities of chemotherapy-induced amenorrhea were 7.2% for women diagnosed before age 30 years, 33% for women age 31 to 44 years, and 79% for women diagnosed after age 45 years (P trend amenorrhea was higher for women who received tamoxifen than for those who did not (52% v 29%; P amenorrhea in women who carry a BRCA1 or BRCA2 mutation. The risk of induced long-term amenorrhea does not seem to be greater among mutation carriers than among women who do not carry a mutation.

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

Directory of Open Access Journals (Sweden)

Mansoureh Tabatabaeifar

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

Characterization of ultraviolet light-induced diphtheria toxin-resistant mutations in normal and Xeroderma pigmentosum human fibroblasts

International Nuclear Information System (INIS)

Glover, T.W.

1979-01-01

Quantitative mutagenesis studies in human cells have been severely limited by the lack of reliable genetic markers. Experiments were therefore performed to develop and characterize a better quantitative mutation assay for human cells. The uv-induction of diphtheria toxin resistant (DT/sup r/) mutations in normal and excision repair defective xeroderma pigmentosum (XP) fibroblasts has been quantitatively characterized. A concentration of diphtheria toxin to use in the selection of resistant mutants was determined whereby DT/sup r/ cells are cross-resistant to Pseudomonas aeurginosa exotoxin A, indicating mutants have altered elongation factor-2 (EF-2) which is not susceptible to ADP-ribosylation by either toxin. Results of this study indicate that XP fibroblasts have higher uv-induced mutation frequencies per unit uv-dose but similar frequencies per unit survival compared to normal cells as measured using a new genetic marker for quantitative mutagenesis. Furthermore, these results support a prediction of the mutation theory of cancer, namely, that cells from individuals with certain human syndromes that predispose the individual to cancer will have higher induced mutation frequencies than cells from non-susceptible individuals. This newly characterized genetic marker should be useful in quantitative mutagenesis studies in human cells

Effects of a chromosome-3 mutator gene on radiation-induced mutability in Drosophila melanogaster females

Energy Technology Data Exchange (ETDEWEB)

Sankaranarayanan, K. (Rijksuniversiteit Leiden (Netherlands). Dept. of Radiation Genetics and Chemical Mutagenesis; Cohen (J.A.) Inst. voor Radiopathologie en Stralenbescherming, Leiden (Netherlands))

1982-01-01

A series of X-irradiation experiments was carried out using Drosophila melanogaster females homozygous for a third chromosome mutator gene and females which had a similar genetic background except that the mutator-bearing third chromosomes were substituted by normal wild-type chromosomes. In the present work, the sensitivity of the pre-meiotic germ cells of mutator and normal females to the X-ray induction (2000 R) of sex-linked recessive lethals was studied. In addition, experiments were conducted to examine the sensitivity of the immature (stage 7; prophase I of meiosis) oocytes of both kinds of females to the induction of dominant lethals, X-linked recessive lethals and X-chromosome losses. The results show that in pre-meiotic germ cells, the frequencies of radiation-induced recessive lethals are similar in both kinds of females. However, the proportion of these mutations that occur in clusters of size 3 and higher, is higher in mutator than in normal females. In stage-7 oocytes, the frequencies of radiation-induced dominant lethals and sex-linked recessive lethals were similar in both kinds of females. The X-loss frequencies however, were consistently higher in mutator females although statistical significance was obtained only at higher exposures (3000 and 3750 R) and not at lower ones (750-2250 R). Possible reasons for the discrepancy between the present results and those of Gold and Green with respect to pre-meiotic germ cells are discussed.

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

International Nuclear Information System (INIS)

Datta, S.K.

2002-01-01

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 (M 1 V 1 , M 1 V 2 , M 1 V 3 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

Mutation induction by and mutational interaction between monochromatic wavelength radiations in the near-ultraviolet and visible ranges

International Nuclear Information System (INIS)

Tyrrell, R.M.

1980-01-01

The induction of mutations (reversion to tryptophan independence) by various UV (254, 313, 334 and 365 nm) and visible (405 and 434 nm) wavelengths was measured in exponential phase populations of Escherichia coli B/r thy trp and B/r thy trp uvr A by assay of irradiated populations on semi-enriched media. No mutations were induced in the repair proficient strain at wavelengths longer than 313 nm. Mutations were induced to the excisionless strain at wavelengths as long as 405 nm but less than expected from the known amount of DNA damage induced. Irradiation at the long wavelenths (434, 405, 365 and 334 nm) suppressed the appearance of 254- or 313 nm-induced mutations in the repair competent strain but not in the excision deficient strain. The relative dose-requirement for mutation suppression was related to the relative efficiency of these wavelengths in inducing growth delay. These results suggest that the growth delay induced by near-UV and visible wavelenghts allows more time for the 'error-free' excision repair process to act on the potentially mutagenic lesions induced by 254- and 313-nm radiations, thereby reducing the mutation frequency observed in the repair-proficient strain. The level of near-UV mutation induced in the excision deficient strain is lower than expected from the DNA damage known to be induced. It is possible that near-UV radiation induces a class of lethal lesions that are not susceptible to error-prone repair. (author)

UV-induced tandem double mutations in the trpA gene of E. coli

International Nuclear Information System (INIS)

Piechocki, R.; Langhammer, R.

1980-01-01

The ultraviolet light induction of tandem double mutations in a reverse mutation system was shown using trpA mutants which are characterized by the codon sequences GAA and AAG in codon position 211. Among 597 Trp + independent revertants of the trpA (AAG211) strain 3 full revertants were detected arising from UV-induced tandem double base exchanges. In the codon unit 211 full revertants due to single base exchanges are at least 20 times as frequent as full revertants due to tandem double base exchanges. (author)

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

International Nuclear Information System (INIS)

Dumaz, N.; Drougard, C.; Sarasin, A.; Daya-Grosjean, L.

1993-01-01

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

Bibliography. Examples of literature related to the use of induced mutations in cross-breeding

International Nuclear Information System (INIS)

Micke, A.

1976-01-01

The bibliography contains about 400 references arranged alphabetically under the following 20 headings: Genetic analysis of mutants; Mutant gene combination and interaction; Pleiotropy versus linkage; Genetic background; Heterosis and overdominance; Mutations in heterozygous plants such as vegetatively propagated plants; Mutations in hybrids of self-pollinators; Distant hybridization; Increasing recombination; Alteration in the reproductive system; Alteration of photoperiodic response; Self and cross-incompatibility; Male or female sterility; Adaptability of mutants and mutant hybrids; Mutation induction in cross pollinators; Dwarfing mutant genes in cross-breeding; Protein mutants in cross-breeding; Disease resistant mutants in cross-breeding; Practical cross-breeding programmes using mutants; Spontaneous versus induced genetic diversity

X-ray-induced specific-locus mutations in the ad-3 region of two-component heterokaryons of Neurospora crass

International Nuclear Information System (INIS)

De Serres, F.J.

1990-01-01

More extensive complementation tests than those performed initially on a series of 832 X-ray-induced specific-locus mutations in the adenine-4 (ad-3) region of a two-component heterokaryon (H-12) of Neurospora crassa showed that unexpectedly high frequencies of specific-locus mutations in the ad-3 region have additional, but separate, sites of recessive lethal damage in the immediately adjacent genetic regions. In the present paper, X-ray-induced irreparable ad-3 mutants of the folowing genotypes and numbers (ad-3A ad-3B, ad-3A ad-3B nic-2, and ad-3B nic-2) have also subjected to the same genetic fine structure analysis. These experiments, in the previous and present papers, were designed to determine the extent of the functional inactivation in the ad-3 and immediately adjacent genetic regions in individual mutants classified as presumptive multilocus deletions or multiplelocus mutations. The data in the present paper have shown that in Neurospora crassa most X-ray-induced irreparable mutants of genotype ad-3A ad-3B, ad-3A ad-3B nic-2, and ad-3 nic-2 map as a series of overlapping multilocus deletions. In addition, genetic fine structure analysis has shown that some of the mutants classified, initially, as multilocus deletions, are actually multiple-locus mutations: multilocus deletions with closely linked, and separate, sites of recessive lethal damage with a wide variety of genotyes. Combining data from the present experiments with previously published date, the frequency of multiple-locus mutations among X-ray-induced gene/point mutations and multilocus deletions in the ad-3 region is 6.2%. (author). 27 refs.; 4 figs.; 7 tab

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

International Nuclear Information System (INIS)

Donini, B.

1982-01-01

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)

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

International Nuclear Information System (INIS)

Mukh-Syaifudin

2006-01-01

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

Gamma-ray induced mutation breeding in tree fruit crops

International Nuclear Information System (INIS)

Ito, Yuji

1998-01-01

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

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....

Studies on mutation techniques in rice breeding

International Nuclear Information System (INIS)

Wang Cailian; Chen Qiufang; Jin Wei

2001-01-01

Synthetical techniques for improving rice mutation breeding efficiency were studied. The techniques consist of corresponding relationship between radiosensitivity and mutation frequency, choosing appropriate materials, combination of physical and chemical mutagens, mutagenic effects of the new mutagenic agents as proton, ions, synchronous irradiation and space mutation. These techniques and methods for inducing mutations are very valuable to increase inducing mutation efficiency and breeding level

RFLP analysis of rice semi-dwarf mutation induced by high energy argon ion radiation

International Nuclear Information System (INIS)

Zhuang Chuxiong; Hu Weimin; Mei Mantong

1997-01-01

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 Bianpizhen 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

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

International Nuclear Information System (INIS)

Zhuang Chuxiong; Hu Weimin; Mei Mantong

1997-01-01

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)

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.

Induced Mutations for Improving Production on Bread and Durum Wheat

International Nuclear Information System (INIS)

Stamo, Ilirjana; Ylli, Ariana; Dodbiba, Andon

2007-01-01

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

Next-Gen Sequencing-Based Mapping and Identification of Ethyl Methanesulfonate-Induced Mutations in Arabidopsis thaliana.

Science.gov (United States)

Zhang, Xue-Cheng; Millet, Yves; Ausubel, Frederick M; Borowsky, Mark

2014-10-01

Forward genetic analysis using ethyl methanesulfonate (EMS) mutagenesis has proven to be a powerful tool in biological research, but identification and cloning of causal mutations by conventional genetic mapping approaches is a painstaking process. Recent advances in next-gen sequencing have greatly invigorated the process of identifying EMS-induced mutations corresponding to a specific phenotype in model genetic hosts, including the plant Arabidopsis thaliana and the nematode Caenorhabditis elegans. Next-gen sequencing of bulked F2 mutant recombinants produces a wealth of high-resolution genetic data, provides enhanced delimitation of the genomic location of mutations, and greatly reduces hands-on time while maintaining high accuracy and reproducibility. In this unit, a detailed procedure to simultaneously map and identify EMS mutations in Arabidopsis is described. Copyright © 2014 John Wiley & Sons, Inc.

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

International Nuclear Information System (INIS)

Pawar, S.E.; Wanjari, K.B.

1994-01-01

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

Utilization of induced mutation techniques in rice improvement in the Philippines

International Nuclear Information System (INIS)

Asencion, A.B.; Santos, I.S.; Barrida, A.C.; Medina, F.I.S. III

2001-01-01

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)

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)

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

International Nuclear Information System (INIS)

Paul, P.; Fujiwara, Y.

1981-01-01

Microbial protease inhibitors elastatinal and leupeptin were tested for cytotoxicity and for effects on spontaneous and u.v.-induced 6-thioguanine-resistant (6TGsup(r)) 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 exposures of 6-8 h and this was partially abolished by the presence of 2.5 μg 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 6TGsup(r) mutation and SCE. However, reconstruction experiments revealed that pretreatments of 6TGsup(r) and 6TGsup(s) (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 nor mutagenic by themselves, and do not alter mutation fixation and expression. (author)

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

International Nuclear Information System (INIS)

Paul, P.; Fujiwara, Y.

1981-01-01

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

Effect of genes controlling radiation sensitivity on chemically induced mutations in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, L.

1976-01-01

The effect of 16 different genes (rad) conferring radiation sensitivity on chemically induced reversion in the yeast Saccharomyces cerevisiae was determined. The site of reversion used was a well-defined chain initiation mutant mapping in the structural gene coding for iso-1-cytochrome c. High doses of EMS and HNO 2 resulted in decreased reversion of cyc1-131 in rad6, rad9 and rad15 strains compared to the normal RAD + strains. In addition, rad52 greatly decreased EMS reversion of cyc1-131 but had no effect on HNO 2 -induced reversion; rad18, on the other hand, increased HNO 2 -induced reversion but did not alter EMS-induced reversion. When NQO was used as the mutagen, every rad gene tested, except for rad18, had an effect on reversion; rad6, rad9, rad15, rad17, rad18, rad22, rev1, rev2, and rev3 lowered NQO reversion while rad1, rad2, rad3, rad4, rad10, rad12, and rad16 increased it compared to the RAD + strain. The effect of rad genes on chemical mutagenesis is discussed in terms of their effect on uv mutagenesis. It is concluded that although the nature of the repair pathways may differ for uv- and chemically-induced mutations in yeast, a functional repair system is required for the induction of mutation by the chemical agents NQO, EMS, and HNO 2

The influence of large deletions on the mutation frequency induced by tritiated water and X-radiation in male Drosophila melanogaster post-meiotic germ cells

International Nuclear Information System (INIS)

Fossett, N.G.; Byrne, B.J.; Kelley, S.J.; Tucker, A.B.; Arbour-Reily, P.; Lee, W.R.

1994-01-01

Tritium beta radiation ( 3 H β-radiation) in the form of tritiated water was used to induce mutations at the alcohol dehydrogenase (Adh) locus in male Drosophila melanogaster post-meiotic germ cells. All 23 Adh null mutations were large deletions (>20 kb), determined by genetic complementation and Southern blot analyses. 27 Adh null mutations have been induced by 100-kVp X-rays and have been genetically and molecularly characterized. In contrast to 3 H β-radiation, 100-kVp X-rays induced a bimodal distribution of Adh null mutations, intragenic mutations, ≤250 bp, and large deletions, >100 kb. A statistically significant difference was observed between the frequency of large deletions (23/23 or 1.0) induced by 3 H β-radiation and the frequency of large deletions (19/27 or 0.7) induced by 100-kVp X-rays. However, a statistical difference was not observed between the size distribution of the large deletions induced by 3 H β-radiation and X-rays. The relative deletion frequency (RDF) induced by 3 H β-radiation and 100-kVp X-rays was (1.0/0.7=1.4). The relative biological effectiveness (RBE) of these two radiation sources was 1.4, determined from the ratio of the regression coefficients of the respective 3 H β-radiation and X-ray sex-linked recessive lethal (SLRL) dose-response data. The large difference in size between the two classes of X-ray-induced Adh null mutations and the increase in mutation frequency and deletion frequency for 3 H β-radiation with respect to X-rays may indicate that the relative deletion frequency (RDF) is the molecular biological basis for the increase in the RBE for radiation sources with a mean LET value ≤10 keV/μm

Advances in improvement of stress tolerance by induced mutation and genetic transformation in alfalfa

International Nuclear Information System (INIS)

Huang Xin; Ye Hongxia; Shu Xiaoli; Wu Dianxing

2008-01-01

In order to provide references for stress-tolerant breeding of alfalfa, genetic basis of stress-tolerant traits was briefly introduced and advanced in improvement of stress-tolerance by induced mutation and genetic transformation in alfalfa were reviewed. (authors)

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-08-05

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

Embryonic left-right separation mechanism allows confinement of mutation-induced phenotypes to one lateral body half of bilaterians.

Science.gov (United States)

Ma, Kun

2013-12-01

A fundamental question in developmental biology is how a chimeric animal such as a bilateral gynandromorphic animal can have different phenotypes confined to different lateral body halves, and how mutation-induced phenotypes, such as genetic diseases, can be confined to one lateral body half in patients. Here, I propose that embryos of many, if not all, bilaterian animals are divided into left and right halves at a very early stage (which may vary among different types of animals), after which the descendants of the left-sided and right-sided cells will almost exclusively remain on their original sides, respectively, throughout the remaining development. This embryonic left-right separation mechanism allows (1) mutations and the mutation-induced phenotypes to be strictly confined to one lateral body half in animals and humans; (2) mothers with bilateral hereditary primary breast cancer to transmit their disease to their offspring at twofold of the rate compared to mothers with unilateral hereditary breast cancer; and (3) a mosaic embryo carrying genetic or epigenetic mutations to develop into either an individual with the mutation-induced phenotype confined unilaterally, or a pair of twins displaying complete, partial, or mirror-image discordance for the phenotype. Further, this left-right separation mechanism predicts that the two lateral halves of a patient carrying a unilateral genetic disease can each serve as a case and an internal control, respectively, for genetic and epigenetic comparative studies to identify the disease causations. © 2013 Wiley Periodicals, Inc.

Bystander effect-induced mutagenicity in HPRT locus of CHO cells following BNCT neutron irradiation: Characteristics of point mutations by sequence analysis

Energy Technology Data Exchange (ETDEWEB)

Kinashi, Yuko [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka (Japan)], E-mail: kinashi@rri.kyoto-u.ac.jp; Suzuki, Minoru; Masunaga, Shinichiro; Ono, Koji [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka (Japan)

2009-07-15

To investigate bystander mutagenic effects induced by alpha particles during boron neutron capture therapy (BNCT), we mixed cells that were electroporated with borocaptate sodium (BSH), which led to the accumulation of {sup 10}B inside the cells, with cells that did not contain the boron compound. BSH-containing cells were irradiated with {alpha} particles produced by the {sup 10}B(n,{alpha}){sup 7}Li reaction, whereas cells without boron were only affected by the {sup 1}H(n,{gamma}){sup 2}H and {sup 14}N(n,{rho}){sup 14}C reactions. The frequency of mutations induced in the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus was examined in Chinese hamster ovary (CHO) cells irradiated with neutrons (Kyoto University Research Reactor: 5 MW). Neutron irradiation of 1:1 mixtures of cells with and without BSH resulted in a survival fraction of 0.1, and the cells that did not contain BSH made up 99.4% of the surviving cell population. Using multiplex polymerase chain reactions (PCRs), molecular structural analysis indicated that most of the mutations induced by the bystander effect were point mutations and that the frequencies of total and partial deletions induced by the bystander effect were lower than those resulting from the {alpha} particles produced by the {sup 10}B(n,{alpha}){sup 7}Li reaction or the neutron beam from the {sup 1}H(n,{gamma}){sup 2}H and {sup 14}N(n,{rho}){sup 14}C reactions. The types of point mutations induced by the BNCT bystander effect were analyzed by cloning and sequencing methods. These mutations were comprised of 65.5% base substitutions, 27.5% deletions, and 7.0% insertions. Sequence analysis of base substitutions showed that transversions and transitions occurred in 64.7% and 35.3% of cases, respectively. G:C{yields}T:A transversion induced by 8-oxo-guanine in DNA occurred in 5.9% of base substitution mutants in the BNCT bystander group. The characteristic mutations seen in this group, induced by BNCT {alpha} particles

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

International Nuclear Information System (INIS)

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

2003-01-01

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

Induced mutations in pomoid trees breeding

International Nuclear Information System (INIS)

Hamed, Faysal

1986-01-01

Induction of mutations in fruit trees by ionizing radiation complements a cross-breeding program. The objectives are: 1) the improvements of methods of induction, identification and selection of useful mutations, and 2) the initiation of useful mutations either for immediate use as improved cultivars or as a parent material for conventional cross-breeding. The induction of mutants in pomoid fruits, with special emphasis on apple, was realized by gamma-ray treatment of dormant scions subsequently propagated on a rootstoch in the nursery. The aim was to obtain compacts, presuming the feasibility of selecting compact shoots formed by the irradiated scions in the first vegetative generation and also assuming that chance of finding (e.g. fruit mutants) would be thus increased rather than lessened. Selection was carried out on one-season old shoots, formed on the same material for two or three seasons, by using a cut-back at the end of the first and second season. The procedure was highly effective. Moderate exposures, resulting in 60% survival gave high mutation frequencies. Buds 6-10 on the primary shoot gave higher frequencies of recognizable mutations than either buds 1-5 or 11-15. Preliminary results seem to indicate that, at least in some apple cultivars, there is opportunity to obtain compact growth types with good biological characteristics. 8 refs. (author)

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

International Nuclear Information System (INIS)

Kharkwal, M.C.

1998-01-01

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

DNA replication in necessary for fixing induced mutations to streptomycin-resistance in UV-irradiated Escherichia coli cells

Energy Technology Data Exchange (ETDEWEB)

Dubinin, N P; Filippov, V D

1986-01-01

A suspension of E.coli cells has been subjected to UV radiation, then it has been incubated in the growth medium for 15 min. After that one of the portions was incubated with nalidixic acid (NA), and the other one without it in the presence of an antibiotic. Frequency of mutations depending on or irrespective of photoactivation, has been determined. Dependence of Str mutation fixing, induced by low UV radiation doses, on DNA synthesis is determined. Results indicate that both photoreactivation of mutations and its senstivity to mfd system are simultaneously lost.

In vivo somatic mutation systems in the mouse

International Nuclear Information System (INIS)

Russell, L.B.

1979-01-01

In an effort to meet the need for a fast and cheap in vivo prescreen for inherited mammalian point mutations, a somatic forward-mutation method, originally developed in an x-ray experiment, has more recently been tested in work with chemical mutagens. The method makes use of coat-color mutations because the gene product is usually locally expressed, mosaics can be detected with minimal effort, and opportunities for making comparison with induction of germinal point mutations are greatest.--Following treatment of embryos that are heterozygous at specific coat-color loci, various induced genetic changes can result in expression of the recessive (RS) in clones derived from mutant melanocyte precursor cells. However, other events, such as decrease in the number of precursor cells, or disturbed differentiation, can also result in spots, which with careful classification can usually be distinguished from RS's on the basis of their location and color. When this is done, the relative RS frequencies for a series of compounds at least roughly parallel the relative spermatogonial mutation rates. The fact that easily measurable (though low) RS rates are obtained with compounds that have yielded negative results in spermatogonial tests is not surprising in view of the fact that RS's can be caused by several mechanisms besides point mutation.--In spite of the parallelism observed in one laboratory, the usefulness of the in vivo somatic mutation method as a prescreen could come to be doubted because of major discrepancies between results of similar experiments at different laboratories. However, It appears probable that at least some of these discrepancies are due to failure to discriminate between spots that probably resulted from melanocyte insufficiency and spots that resulted from expression of the recessive.--Reverse somatic mutation systems can potentially avoid some of the pitfalls of forward mutation systems. Such system are still in developmental stages

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

International Nuclear Information System (INIS)

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

2012-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-07-01

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

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

Science.gov (United States)

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

2018-05-01

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

Jatropha curcas improvement Induced mutation: Thies University Senegal

International Nuclear Information System (INIS)

Diédhiou, Ibrahima

2011-06-01

The objectives are: 1. to collect accessions of Jatropha curcas in Senegal and establish the genetic variability of this collection. 2. to improve the oil yield of Jatropha curcas by using radiation induced mutation methods to produce highly productive genotypes adapted to local conditions. The choice of Jatropha Curcas is explained by: * Intensive cultivation of Jatropha curcas initiated in many countries of West Africa to produce biodiesel. *There is a craze of private companies to promote this new agricultural value chain. * Jobs and substantial revenues are expected for the rural. *Unfortunately, there is little reliable knowledge to support this dynamic development. Also, the preliminary results showed a high variability of agro-morphological traits in local accessions which could affect negatively the profitability.

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

International Nuclear Information System (INIS)

Lapade, Avelina G.; Veluz, Ana Maria S.; Marbella, Lucia J.; Rama, Manny G.

2001-01-01

Mutation breeding using cobalt-60 ( 60 Co) 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 M 2 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 V 3 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)

SETBP1 mutations drive leukemic transformation in ASXL1-mutated MDS.

Science.gov (United States)

Inoue, D; Kitaura, J; Matsui, H; Hou, H-A; Chou, W-C; Nagamachi, A; Kawabata, K C; Togami, K; Nagase, R; Horikawa, S; Saika, M; Micol, J-B; Hayashi, Y; Harada, Y; Harada, H; Inaba, T; Tien, H-F; Abdel-Wahab, O; Kitamura, T

2015-04-01

Mutations in ASXL1 are frequent in patients with myelodysplastic syndrome (MDS) and are associated with adverse survival, yet the molecular pathogenesis of ASXL1 mutations (ASXL1-MT) is not fully understood. Recently, it has been found that deletion of Asxl1 or expression of C-terminal-truncating ASXL1-MTs inhibit myeloid differentiation and induce MDS-like disease in mice. Here, we find that SET-binding protein 1 (SETBP1) mutations (SETBP1-MT) are enriched among ASXL1-mutated MDS patients and associated with increased incidence of leukemic transformation, as well as shorter survival, suggesting that SETBP1-MT play a critical role in leukemic transformation of MDS. We identify that SETBP1-MT inhibit ubiquitination and subsequent degradation of SETBP1, resulting in increased expression. Expression of SETBP1-MT, in turn, inhibited protein phosphatase 2A activity, leading to Akt activation and enhanced expression of posterior Hoxa genes in ASXL1-mutant cells. Biologically, SETBP1-MT augmented ASXL1-MT-induced differentiation block, inhibited apoptosis and enhanced myeloid colony output. SETBP1-MT collaborated with ASXL1-MT in inducing acute myeloid leukemia in vivo. The combination of ASXL1-MT and SETBP1-MT activated a stem cell signature and repressed the tumor growth factor-β signaling pathway, in contrast to the ASXL1-MT-induced MDS model. These data reveal that SETBP1-MT are critical drivers of ASXL1-mutated MDS and identify several deregulated pathways as potential therapeutic targets in high-risk MDS.

Mutation Breeding Newsletter. No. 39

International Nuclear Information System (INIS)

1992-01-01

This newsletter contains brief articles on the use of radiation to induce mutations in plants; radiation-induced mutants in Chrysanthemum; disrupting the association between oil and protein content in soybean seeds; mutation studies on bougainvillea; a new pepper cultivar; and the use of mutation induction to improve the quality of yam beans. A short review of the seminar on the use of mutation and related biotechnology for crop improvement in the Middle East and Mediterranean regions, and a description of a Co-ordinated Research Programme on the application of DNA-based marker mutations for the improvement of cereals and other sexually reproduced crop species are also included. Two tables are given: these are based on the ''FAO/IAEA Mutant Varieties Database'' and show the number of mutated varieties and the number of officially released mutant varieties in particular crops/species. Refs and tabs

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

Energy Technology Data Exchange (ETDEWEB)

Mashnenkov, A S [Krasnodar Research Institute of Agriculture, Krasnodar (USSR)

1990-01-01

Full text: Seed samples of 9 inbreds were treated with MNU. Mutant individuals were visually selected in M{sub 2} and M{sub 3}. 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)

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

International Nuclear Information System (INIS)

Mashnenkov, A.S.

1990-01-01

Full text: Seed samples of 9 inbreds were treated with MNU. Mutant individuals were visually selected in M 2 and M 3 . 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)

Mutations induced by X-rays and UV radiation during the nuclear cycle in the yeast Schizosarccharomyces pombe

International Nuclear Information System (INIS)

Barale, R.; Rusciano, D.; Loprieno, N.

1982-01-01

The availability of a cell-division-cycle (cdc) mutant in the fission yeast S. pombe, wee 1-50, has made possible the production of a large population of G 1 nuclear-stage synchronized cells. During their development, yeast cells from the G 1 into the G 2 nuclear stages were treated with X-rays and UV radiation at various doses. The DNA pre-replicative and replicative phases were the most sensitive to both cell lethality and mutant induction with either X-rays or UV radiation. The trends of induced biological effects that were observed suggest that the induction of mutations is dependent on the number of unrepaired DNA lesions that reach the replicating fork or of those that occur at that time. The X-ray-induced mutations were earlier saturated, possibly because of the higher number of lethal lesions so induced. (orig.)

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.

Sequencing analysis of mutations induced by N-ethyl-N-nitrosourea at different sampling times in mouse bone marrow.

Science.gov (United States)

Wang, Jianyong; Chen, Tao

2010-03-01

In our previous study (Wang et al., 2004, Toxicol. Sci. 82: 124-128), we observed that the cII gene mutant frequency (MF) in the bone marrow of Big Blue mice showed significant increase as early as day 1, reached the maximum at day 3 and then decreased to a plateau by day 15 after a single dose of carcinogen N-ethyl-N-nitrosourea (ENU) treatment, which is different from the longer mutation manifestation time and the constancy of MFs after reaching their maximum in some other tissues. To determine the mechanism underlying the quick increase in MF and the peak formation in the mutant manifestation, we examined the mutation frequencies and spectra of the ENU-induced mutants collected from different sampling times in this study. The cII mutants from days 1, 3 and 120 after ENU treatment were randomly selected from different animals. The mutation frequencies were 33, 217, 305 and 144 x 10(-6) for control, days 1, 3, and 120, respectively. The mutation spectra at days 1 and 3 were significantly different from that at day 120. Considering that stem cells are responsible for the ultimate MF plateau (day 120) and transit cells are accountable for the earlier MF induction (days 1 or 3) in mouse bone marrow, we conclude that transit cells are much more sensitive to mutation induction than stem cells in mouse bone marrow, which resulted in the specific mutation manifestation induced by ENU.

Comparative studies of dose-response curves for recessive lethal mutations induced by ethylnitrosourea in spermatogonia and in spermatozoa of Drosophila melanogaster

Energy Technology Data Exchange (ETDEWEB)

Yoshikawa, I.; Ayaki, T.; Ohshima, K.

1984-01-01

Induction of recessive lethal mutation by N-ethyl-N-nitrosourea (ENU) was studied for the second chromosome of spermatogonia and spermatozoa in Drosophila melanogaster. ENU (0.03, 0.3, and 1.0 mM) was given to flies by dissolving it in feeding sucrose solution. When plotted against absorbed doses of ENU, the observed frequencies to recessive lethals showed a linear relationship for induction in spermatozoa but a sigmoidal relationship for induction in spermatogonia. These results suggest that in spermatogonia ENU-induced mutational damage is more repairable in a lower dose range of ENU. Mosaic lethal mutations were induced by ENU but not in spermatogonia.

Sequential mutations in Notch1, Fbxw7, and Tp53 in radiation-induced mouse thymic lymphomas.

Science.gov (United States)

Jen, Kuang-Yu; Song, Ihn Young; Banta, Karl Luke; Wu, Di; Mao, Jian-Hua; Balmain, Allan

2012-01-19

T-cell acute lymphoblastic lymphomas commonly demonstrate activating Notch1 mutations as well as mutations or deletions in Fbxw7. However, because Fbxw7 targets Notch1 for degradation, genetic alterations in these genes are expected to be mutually exclusive events in lymphomagenesis. Previously, by using a radiation-induced Tp53-deficient mouse model for T-cell acute lymphoblastic lymphoma, we reported that loss of heterozygosity at the Fbxw7 locus occurs frequently in a Tp53-dependent manner. In the current study, we show that these thymic lymphomas also commonly exhibit activating Notch1 mutations in the proline-glutamic acid-serine-threonine (PEST) domain. Moreover, concurrent activating Notch1 PEST domain mutations and single-copy deletions at the Fbxw7 locus occur with high frequency in the same individual tumors, indicating that these changes are not mutually exclusive events. We further demonstrate that although Notch1 PEST domain mutations are independent of Tp53 status, they are completely abolished in mice with germline Fbxw7 haploinsufficiency. Therefore, Notch1 PEST domain mutations only occur when Fbxw7 expression levels are intact. These data suggest a temporal sequence of mutational events involving these important cancer-related genes, with Notch1 PEST domain mutations occurring first, followed by Fbxw7 deletion, and eventually by complete loss of Tp53.

Improving protein quality of soybean through induced mutations

International Nuclear Information System (INIS)

Manjaya, J.G.

2011-01-01

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Improvements of root and tuber crops in tropical countries of Asia by induced mutations. Proceedings of a final research co-ordination meeting held in Kagoshima, Japan, 22-26 February 1993

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

Root and tuber crops like potato, sweet potato are important starchy foods in tropical countries. However, being vegetatively propagated or difficult to reproduce by seeds, these crops remained in a relatively primitive state in terms of plant breeding. This proceeding contains research papers that deal with the use of external irradiation or induced mutations techniques that are expected to broaden their genetic diversity, thus facilitating screening for desired characteristics.

Manual on mutation breeding. 2. ed.

International Nuclear Information System (INIS)

1977-01-01

The manual is a compilation of work done on the use of induced mutations in plant breeding, and presents general methods and techniques in this field. The use of chemical mutagens and ionizing radiations (X-rays, gamma rays, α- and β-particles, protons, neutrons) are described as well as the effects of these mutagens. The different types of mutations achieved can be divided into genome mutations, chromosome mutations and extra nuclear mutations. Separate chapters deal with mutation techniques in breeding seed-propagated species and asexually propagated plants (examples of development of cultivars given). Plant characters which can be improved by mutation breeding include yield, ripening time, growth habit, disease resistance and tolerance to environmental factors (temperature, salinity etc.). The use of mutagens for some specific plant breeding problems is discussed and attention is also paid to somatic cell genetics in connection with induced mutations. The manual contains a comprehensive bibliography (60 p. references) and a subject index

X-ray-induced specific-locus mutations in the ad-3 region of two-component heterokaryons of Neurospora crassa

International Nuclear Information System (INIS)

Serres, F.J. de

1989-01-01

More extensive genetic tests have been preformed on a series of 832 X-ray-induced specific-locus mutations in the ad-3 region of a 2-component heterokaryon of Neurospora crassa, reported earlier. Using new tester strains and techniques for performing large-scale genetic tests to characterize ad-3 mutants induced in 2-component heterokaryons, new data have been obtained on this sample of X-ray-induced mutants. These new data show that unexpectedly high frequencies of both single-locus mutations and multilocus deletions in the ad-3 region have addition, but separate, sites of recessive lethal damage in the imeediately adjacent genetic regions. The frequencies of these X-ray-induced multiple-locus mutants in the ad-3 region are orders of magnitude higher than expected on the basis of target theory and classical models of chromosome structure during interphase. Current models of interphase chromosome structure in higher eukaryotes as revealed by chromosome 'painting' offer a possible explanation of the Neurospora data. (author). 25 refs.; 5 figs

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

International Nuclear Information System (INIS)

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

1985-01-01

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

Mutational specificity of γ-rays

International Nuclear Information System (INIS)

Hoebee, Barbara.

1990-01-01

The aim of the study described in this thesis was to get more information on the mutagenic properties of radiation-induced DNA modifications and the possible mechanisms involved in radiation-induced mutagenesis, principally by investigating the kinds of mutations by DNA sequence analysis. The mutations were analyzed after γ-irradiation of recombinant bacteriophage M13 and plasmide pUC DNA in diluted aqueous solutions, followed by transfection or transformation to E. coli cells, in which the damaged DNA molecules are repaired and replicated. Error-prone repair, misrepair or bypass of lesions during replication may lead to the introduction of mutations. Both the M13 and the plasmid DNA used in our mutation studies contain a mutation target sequence, which makes an easy selection and sequence analysis of mutant DNA molecules possible. Under the radiation conditions used, e.g. irradiation of diluted aqueous DNA solutions, only DNA damage occurs introduced by the water derived OH* and H* radicals and the hydrated electrons. By using different gas conditions during irradiation the relative yields of these reaction species can be manipulated, which opens up the opportunity to determine their effects separately. The mutation spectrum obtained in double-stranded (ds) M13DNA after irradiation under oxic conditions and the mutation spectrum obtained under the same conditions and in the same mutation target but cloned in plasmid DNA, are described. The mutation specificity under anoxic conditions in ds M13DNA is given. Results obtained after irradiation of ds M13DNA under N 2 conditions are discussed together with experiments with single-stranded DNA. Similarities and differences between radiation-induced mutation spectra obtained by other groups and those presented in this thesis are discussed. (author). 155 refs.; 134 figs.; 16 tabs

Radiation-Induced Mutation and Crop Improvement

International Nuclear Information System (INIS)

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

1987-01-01

Radiation induced mutations have not only been used directly as a cultivar in crop plants, but also indirectly as a genetic resource that is essential to conventional plant breeding. M 1 plant survivals of three rice cultivars treated with gamma rays of 200-350 Gy varied from 30-40%. The survival of the Sawing variety was less sensitive to radiation, but its fertility was more sensitive in comparison with Seomjin and Sponging. Various dwarf or semi-dwarf mutants and early=matured mutants have been selected in the M 2 and M 3 generations of the three rice cultivars irradiated with gamma rays. Other desirable mutants also have been selected, such as high-yielding, high-tailoring and disease-resistant. The genetic nature of most of the selected short calm and earliness mutants was fixed in M 2 or M 3 generations. Dwarfism of IEAR 308 and Monogynol 10 were found to have a single recessive gene. However, the dwarf of IEAR 308 has a recessive deficit phenomenon. The highest genetic heritability of plant height was observed in the cross combination of Monogynol 10 Χ Pawling

Induced mutation breeding in fruit trees

International Nuclear Information System (INIS)

Sanada, Tetsuro

1988-01-01

The black spot disease of Japanese pear is the most serious disease, and Nijusseiki which is one of the leading cultivars of Japanese pear is known to be susceptible to the disease. One branch of a tree planted at the distance of 53 m from a Co-60 source (15 R/day) was selected as a mutant resistant to the disease in 1981, as the spraying of fungicide was reduced when the pathogen was naturally inoculated. The symptom of black spot disease on the mutant observed under field conditions for the period of 5 years after the selection was minimal. The characteristics and the resistance of this mutant were examined. The development of a simple and reliable selection method is essential for mutation breeding. A selection method using a phytotoxin solution was developed. The induced mutant was obviously different from the original Nijusseiki in the susceptibility to the disease, but its resistance was medium. The faint brown spots observed on the leaves and fruit skins of the mutant were due to the aggregation of cytoplasm only in epidermal cells. By the selection method developed, about 500 shoots can be screened in a day. (Kako, I.)

Induced mutation breeding by fast neutron

International Nuclear Information System (INIS)

Chen Zhengba; You Risheng

1988-09-01

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 10 11 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 10 8 cm 2 )

Improvements of root and tuber crops in tropical countries of Asia by induced mutations. Proceedings of a final research co-ordination meeting held in Kagoshima, Japan, 22-26 February 1993

International Nuclear Information System (INIS)

1995-07-01

Root and tuber crops like potato, sweet potato are important starchy foods in tropical countries. However, being vegetatively propagated or difficult to reproduce by seeds, these crops remained in a relatively primitive state in terms of plant breeding. This proceeding contains research papers that deal with the use of external irradiation or induced mutations techniques that are expected to broaden their genetic diversity, thus facilitating screening for desired characteristics. Refs, figs and tabs

MT-CYB mutations in hypertrophic cardiomyopathy

DEFF Research Database (Denmark)

Hagen, Christian M; Aidt, Frederik H; Havndrup, Ole

2013-01-01

Mitochondrial dysfunction is a characteristic of heart failure. Mutations in mitochondrial DNA, particularly in MT-CYB coding for cytochrome B in complex III (CIII), have been associated with isolated hypertrophic cardiomyopathy (HCM). We hypothesized that MT-CYB mutations might play an important...... and m.15482T>C; p.S246P were identified. Modeling showed that the p.C93Y mutation leads to disruption of the tertiary structure of Cytb by helix displacement, interfering with protein-heme interaction. The p.S246P mutation induces a diproline structure, which alters local secondary structure and induces...... of HCM patients. We propose that further patients with HCM should be examined for mutations in MT-CYB in order to clarify the role of these variants....

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

International Nuclear Information System (INIS)

Micke, A.

1996-01-01

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

Mutation breeding newsletter. No. 33

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-01-01

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.

Mutation breeding newsletter. No. 33

International Nuclear Information System (INIS)

1989-01-01

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

Crop improvement through mutation techniques in Chinese agriculture

International Nuclear Information System (INIS)

Wen, X.; Qu, L.

1996-01-01

Induced mutations for crop improvement is the most developed field in China's nuclear-agricultural sciences. It is well known that China has supported 22% of the world's population with only 7% of its cultivated land. The continued rise in population stresses the importance of increasing food production. Although developing crop varieties is efficient in increasing food production, plant breeders are approaching the outer limits of existing and useful genetic variability. As nuclear techniques provide an efficient route to inducing genetic mutations, more and more efforts have been focused on induced genetic variability. Induced mutations have become an effective way of improving cultivars and supplementing existing germplasm. Since 1981 two nationwide co-operation programs for mutation breeding, organized by the IAEA, have been carried out. 3 tabs

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

International Nuclear Information System (INIS)

Bhatia, C.R.; Nichterlein, K.; Maluszynski, M.

1999-01-01

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)

In vitro techniques for selection of radiation induced mutations adapted to adverse environmental conditions. Proceedings of a final research co-ordination meeting

International Nuclear Information System (INIS)

2001-06-01

The ever increasing human population and dwindling land and water resources worldwide make it essential to produce more food, fibre and fodder from less and less land. During the last century, plant breeding contributed remarkably to increasing food by producing varieties which give higher yield, have improved quality and nutrition, and resist diseases and pests. Nearly 50% of the increase in food production in Asia during the last fifty years can be attributed to the high yielding, short height varieties of rice and wheat, the remaining to the improved agronomic inputs and management. Many crops, such as cassava, potato, pineapple, sweet potato, sugarcane, banana and plantain are major food crops, and others such as sugarcane and pineapple are important to the economies of many developing countries. One of the solutions to have a sustainable and secure food production is to breed varieties which are tolerant of stress conditions during their growth and development. Hence a Co-ordinated Research Project on In vitro Techniques for Selection of Radiation Induced Mutations Adapted to Adverse Environmental Conditions was initiated and focused primarily on the improvement of vegetatively propagated plants. Since the inception of this project, several participating scientists established the optimal dose requirement for in vitro cultured material. Investigations were carried out on the effect of radiation to alter traits which affect survival under stress conditions and high temperature stress in potato, pineapple, sweet potato and garlic. The possibility to change traits such as tolerance to saline and water logged soils in sugarcane and gene regulation for salinity tolerance were studied. The limited number of available reports suggest that callus cultures are much more sensitive to radiation treatment and require much lower doses (2 to 5 Gy) than stem cuttings or seeds, and that relatively higher doses (15 to 20 Gy) cause necrosis or loss of regenerative capacity. The

In vitro techniques for selection of radiation induced mutations adapted to adverse environmental conditions. Proceedings of a final research co-ordination meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-06-01

The ever increasing human population and dwindling land and water resources worldwide make it essential to produce more food, fibre and fodder from less and less land. During the last century, plant breeding contributed remarkably to increasing food by producing varieties which give higher yield, have improved quality and nutrition, and resist diseases and pests. Nearly 50% of the increase in food production in Asia during the last fifty years can be attributed to the high yielding, short height varieties of rice and wheat, the remaining to the improved agronomic inputs and management. Many crops, such as cassava, potato, pineapple, sweet potato, sugarcane, banana and plantain are major food crops, and others such as sugarcane and pineapple are important to the economies of many developing countries. One of the solutions to have a sustainable and secure food production is to breed varieties which are tolerant of stress conditions during their growth and development. Hence a Co-ordinated Research Project on In vitro Techniques for Selection of Radiation Induced Mutations Adapted to Adverse Environmental Conditions was initiated and focused primarily on the improvement of vegetatively propagated plants. Since the inception of this project, several participating scientists established the optimal dose requirement for in vitro cultured material. Investigations were carried out on the effect of radiation to alter traits which affect survival under stress conditions and high temperature stress in potato, pineapple, sweet potato and garlic. The possibility to change traits such as tolerance to saline and water logged soils in sugarcane and gene regulation for salinity tolerance were studied. The limited number of available reports suggest that callus cultures are much more sensitive to radiation treatment and require much lower doses (2 to 5 Gy) than stem cuttings or seeds, and that relatively higher doses (15 to 20 Gy) cause necrosis or loss of regenerative capacity. The

Tbc1d1 mutation in lean mouse strain confers leanness and protects from diet-induced obesity

DEFF Research Database (Denmark)

Chadt, Alexandra; Leicht, Katja; Deshmukh, Atul

2008-01-01

We previously identified Nob1 as a quantitative trait locus for high-fat diet-induced obesity and diabetes in genome-wide scans of outcross populations of obese and lean mouse strains. Additional crossbreeding experiments indicated that Nob1 represents an obesity suppressor from the lean Swiss Jim...... Lambert (SJL) strain. Here we identify a SJL-specific mutation in the Tbc1d1 gene that results in a truncated protein lacking the TBC Rab-GTPase-activating protein domain. TBC1D1, which has been recently linked to human obesity, is related to the insulin signaling protein AS160 and is predominantly...... and reduced glucose uptake in isolated skeletal muscle. Our data strongly suggest that mutation of Tbc1d1 suppresses high-fat diet-induced obesity by increasing lipid use in skeletal muscle....

Mutation induction by ion beams in arabidopsis

International Nuclear Information System (INIS)

Tanaka, Atsushi

1999-01-01

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

Mutation induction by ion beams in arabidopsis

Energy Technology Data Exchange (ETDEWEB)

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

1999-07-01

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

Hypercholesterolemia Induced by a PCSK9 Gain-of-Function Mutation Augments Angiotensin II-Induced Abdominal Aortic Aneurysms in C57BL/6 Mice-Brief Report.

Science.gov (United States)

Lu, Hong; Howatt, Deborah A; Balakrishnan, Anju; Graham, Mark J; Mullick, Adam E; Daugherty, Alan

2016-09-01

Gain-of-function mutations of PCSK9 (proprotein convertase subtilisin/kexin type 9) lead to hypercholesterolemia. This study was to determine whether infection of normocholesterolemic mice with an adeno-associated viral (AAV) vector expressing a gain-of-function mutation of mouse PCSK9 increased angiotensin II (AngII)-induced abdominal aortic aneurysms. In an initial study, male C57BL/6 mice were injected intraperitoneally with either an empty vector or PCSK9 gain-of-function mutation (D377Y). AAV at 3 doses and fed a saturated fat-enriched diet for 6 weeks. Two weeks after AAV injection, mice were infused with AngII for 4 weeks. Plasma PCSK9 concentrations were increased dose dependently in mice injected with AAV containing PCSK9D377Y mutation and positively associated with elevations of plasma cholesterol concentrations. Infection with intermediate and high doses of PCSK9D377Y.AAV led to equivalent increases of maximal width of abdominal aortas in C57BL/6 mice infused with AngII. Therefore, the intermediate dose was used in subsequent experiments. We then determined effects of PCSK9D377Y.AAV infection on 5 normolipidemic mouse strains, demonstrating that C57BL/6 mice were the most susceptible to this AAV infection. PCSK9D377Y.AAV infected male C57BL/6 mice were also compared with age-matched male low-density lipoprotein receptor(-/-) mice. Although plasma cholesterol concentrations were lower in mice infected with PCSK9D377Y.AAV, these mice had equivalent abdominal aortic aneurysmal formation, compared to low-density lipoprotein receptor(-/-) mice. In a separate study, reduced plasma PCSK9 concentrations by PCSK9 antisense oligonucleotides in male low-density lipoprotein receptor(-/-) mice did not influence AngII-induced abdominal aortic aneurysms. AAV-mediated infection with a mouse PCSK9 gain-of-function mutation is a rapid, easy, and efficient approach for inducing hypercholesterolemia and promoting abdominal aortic aneurysms in C57BL/6 mice infused with Ang

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

International Nuclear Information System (INIS)

Bhatia, C.R.; Maluszynski, M.; Nichterlein, K.; Zanten, L. van

2001-01-01

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)

In silico analysis of conformational changes induced by mutation of aromatic binding residues: consequences for drug binding in the hERG K+ channel.

Directory of Open Access Journals (Sweden)

Kirsten Knape

Full Text Available Pharmacological inhibition of cardiac hERG K(+ channels is associated with increased risk of lethal arrhythmias. Many drugs reduce hERG current by directly binding to the channel, thereby blocking ion conduction. Mutation of two aromatic residues (F656 and Y652 substantially decreases the potency of numerous structurally diverse compounds. Nevertheless, some drugs are only weakly affected by mutation Y652A. In this study we utilize molecular dynamics simulations and docking studies to analyze the different effects of mutation Y652A on a selected number of hERG blockers. MD simulations reveal conformational changes in the binding site induced by mutation Y652A. Loss of π-π-stacking between the two aromatic residues induces a conformational change of the F656 side chain from a cavity facing to cavity lining orientation. Docking studies and MD simulations qualitatively reproduce the diverse experimentally observed modulatory effects of mutation Y652A and provide a new structural interpretation for the sensitivity differences.

Better plants through mutations

International Nuclear Information System (INIS)

1988-01-01

This is a public relations film describing problems associated with the genetic improvement of crop plants through induced mutations. Mutations are the ultimate source of genetic variation in plants. Mutation induction is now established as a practical tool in plant breeding. The Joint FAO/IAEA Division and the IAEA's laboratory at Seibersdorf have supported research and practical implementation of mutation breeding of both seed propagated and vegetatively propagated plants. Plant biotechnology based on in vitro culture and recombinant DNA technology will make a further significant contribution to plant breeding

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

International Nuclear Information System (INIS)

Solanki, I.S.; Sharma, B.

2003-01-01

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 M 1 damage, except that some mutation types occurred more frequently, than others in certain groups. (author)

The Pattern and Distribution of Induced Mutations in J. curcas Using Reduced Representation Sequencing

Directory of Open Access Journals (Sweden)

Fatemeh Maghuly

2018-04-01

Full Text Available Mutagenesis in combination with Genotyping by Sequencing (GBS is a powerful tool for introducing variation, studying gene function and identifying causal mutations underlying phenotypes of interest in crop plant genomes. About 400 million paired-end reads were obtained from 82 ethylmethane sulfonate (EMS induced mutants and 14 wild-type accessions of Jatropha curcas for the detection of Single Nucleotide Polymorphisms (SNPs and Insertion/Deletions (InDels by two different approaches (nGBS and ddGBS on an Illumina HiSeq 2000 sequencer. Using bioinformatics analyses, 1,452 induced SNPs and InDels were identified in coding regions, which were distributed across 995 genes. The predominantly observed mutations were G/C to A/T transitions (64%, while transversions were observed at a lower frequency (36%. Regarding the effect of mutations on gene function, 18% of the mutations were located in intergenic regions. In fact, mutants with the highest number of heterozygous SNPs were found in samples treated with 0.8% EMS for 3 h. Reconstruction of the metabolic pathways showed that in total 16 SNPs were located in six KEGG pathways by nGBS and two pathways by ddGBS. The most highly represented pathways were ether-lipid metabolism and glycerophospholipid metabolism, followed by starch and sucrose metabolism by nGBS and triterpenoid biosynthesis as well as steroid biosynthesis by ddGBS. Furthermore, high genome methylation was observed in J. curcas, which might help to understand the plasticity of the Jatropha genome in response to environmental factors. At last, the results showed that continuously vegetatively propagated tissue is a fast, efficient and accurate method to dissolve chimeras, especially for long-lived plants like J. curcas. Obtained data showed that allelic variations and in silico analyses of gene functions (gene function prediction, which control important traits, could be identified in mutant populations using nGBS and ddGBS. However, the

Multi-walled carbon nanotubes (NM401) induce ROS-mediated HPRT mutations in Chinese hamster lung fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Rubio, Laura [Grup de Mutagènesi, Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra (Spain); El Yamani, Naouale [Health Effects Laboratory-MILK, NILU-Norwegian Institute for Air Research, Kjeller (Norway); Kazimirova, Alena [Department of Biology, Slovak Medical University, Bratislava (Slovakia); Dusinska, Maria, E-mail: maria.dusinska@nilu.no [Health Effects Laboratory-MILK, NILU-Norwegian Institute for Air Research, Kjeller (Norway); Marcos, Ricard, E-mail: ricard.marcos@uab.es [Grup de Mutagènesi, Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra (Spain); CIBER Epidemiología y Salud Pública, Instituto de Salud Carlos III, Madrid (Spain)

2016-04-15

Although there is an important set of data showing potential genotoxic effects of nanomaterials (NMs) at the DNA (comet assay) and chromosome (micronucleus test) levels, few studies have been conducted to analyze their potential mutagenic effects at gene level. We have determined the ability of multi-walled carbon nanotubes (MWCNT, NM401), to induce mutations in the HPRT gene in Chinese hamster lung (V79) fibroblasts. NM401, characterized in the EU NanoGenotox project, were further studied within the EU Framework Programme Seven (FP7) project NANoREG. From the proliferation assay data we selected a dose-range of 0.12 to 12 µg/cm{sup 2} At these range we have been able to observe significant cellular uptake of MWCNT by using transmission electron microscopy (TEM), as well as a concentration-dependent induction of intracellular reactive oxygen species. In addition, a clear concentration-dependent increase in the induction of HPRT mutations was also observed. Data support a potential genotoxic/ carcinogenic risk associated with MWCNT exposure. - Highlights: • MWCNT were tested in V79 cells. • Cellular uptake of MWCNT was detected using TEM. • Intracellular ROS induction was observed after MWCNT exposure. • MWCNT induced a concentration-dependent increase of HPRT mutations.

Multi-walled carbon nanotubes (NM401) induce ROS-mediated HPRT mutations in Chinese hamster lung fibroblasts

International Nuclear Information System (INIS)

Rubio, Laura; El Yamani, Naouale; Kazimirova, Alena; Dusinska, Maria; Marcos, Ricard

2016-01-01

Although there is an important set of data showing potential genotoxic effects of nanomaterials (NMs) at the DNA (comet assay) and chromosome (micronucleus test) levels, few studies have been conducted to analyze their potential mutagenic effects at gene level. We have determined the ability of multi-walled carbon nanotubes (MWCNT, NM401), to induce mutations in the HPRT gene in Chinese hamster lung (V79) fibroblasts. NM401, characterized in the EU NanoGenotox project, were further studied within the EU Framework Programme Seven (FP7) project NANoREG. From the proliferation assay data we selected a dose-range of 0.12 to 12 µg/cm 2 At these range we have been able to observe significant cellular uptake of MWCNT by using transmission electron microscopy (TEM), as well as a concentration-dependent induction of intracellular reactive oxygen species. In addition, a clear concentration-dependent increase in the induction of HPRT mutations was also observed. Data support a potential genotoxic/ carcinogenic risk associated with MWCNT exposure. - Highlights: • MWCNT were tested in V79 cells. • Cellular uptake of MWCNT was detected using TEM. • Intracellular ROS induction was observed after MWCNT exposure. • MWCNT induced a concentration-dependent increase of HPRT mutations.

Molecular nature of forvard gene mutations induced by γ- and UV-irradiation ip the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Ivanov, E.L.; Koval'tsova, S.V.; Korolev, V.G.

1983-01-01

Gamma and UV-radiation induce the following mutation spectra in the ADE2 gene of Saccharomyces cerevisial yeast respectively: 27 and 41% of GTs→AT transitions, 8 and 11% of AT→GTs transitions, 59 and 40% transversions, 6 and 8% mutations of the reading fame shift type. The results obtained prove the presence of specific nature of UV rays in respect to induction of GTs→AT transitions. The experimental data are discussed from the point of view of studying molecular mechanisms of radiation mutagenesis

Mutation studies on garden roses: a review

International Nuclear Information System (INIS)

Datta, S.K.

1997-01-01

Most of the modern roses are the result of hybridization, selection and spontaneous mutation. For floriculture trade, there is always demand and necessity for new varieties due to change in taste and fashion. Mutation breeding is an established method for crop improvement. Induced somatic mutation breeding holds promise for effective improvement and have high potential for bringing about genetic improvement and it has led to a great burst of flower colour, form, pattern and other variations in rose by using ionizing radiations. The details of prospects and utilization of induced mutation breeding technique for developing new rose varieties have been compiled. (author)

Manifestation of x-radiation induced sex-linked recessive lethal mutation impairing the development of imaginal disks and gonads in Drosophila Melanogaster

International Nuclear Information System (INIS)

Abeleva, Eh.A.; Ivanov, A.I.

1982-01-01

A study was made of Drosophila melanogaster mutations impairing the development of imaginal disks. The state of gonads in these mutants was not studied. Using X-radiation a lethal mutation in X chromosome was obtained that induced degeneration of imaginal disks at the 3d stage of larva development. The gonads of the mutants at this stage of development vary in size. The transplantation tests showed that the mutation manifests itself in both the imaginal disks and the gonads

Modification of mutation frequency in Saccharomyces Cerevisiae

International Nuclear Information System (INIS)

Vashishat, R.K.; Kakar, S.N.

1976-01-01

In a reverse mutation system, using haploid, histidine-requirinq strain of Saccharomyces cerevisiae, the frequency of uv-induced prototrophs increased if the post-irradiation minimal medium was supplemented with limited amounts of histidine. Addition of natural amino acids or RNA bases in the post-irradiation minimal medium, with or without histidine, also increased the uv-induced mutation frequency. Thus, post-irradiation conditions favouring protein and RNA synthesis, are effective in increasing uv-induced mutations in yeast. As compared to uv light, nitrous acid was more effective in inducing reversions in this strain and the frequency increased if the treated cells were plated on minimal medium supplemented with limited amounts of histidine. However, the addition of amino acids or RNA bases decreased the number of revertants. An additional inclusion of histidine reversed the suppressive effect of these metabolites. The mutation induction processes are thus different or differently modifiable in uv and nitrous acid. (author)

The role of radiation induced mutations in crop Improvement

International Nuclear Information System (INIS)

Souframanien, J.

2017-01-01

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. Gregor Mendel in 1865 used several such natural 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. Primarily, simple selection of desirable offspring and cross breeding were the earlier methods of breeding and this utilized the occurrence of spontaneous mutations. In nature, occurrence of natural variability in the form of spontaneous mutations is extremely low (about 10 -6 ), which can be enhanced several fold (∼10 -3 ) by using ionizing radiations or chemical mutagens

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

International Nuclear Information System (INIS)

Wessendorf, Petra; Vijg, Jan; Nussenzweig, André; Digweed, Martin

2014-01-01

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

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.

Stamina pistilloida: a new mutation induced in pea.

Science.gov (United States)

Monti, L M; Devreux, M

1969-01-01

After diethylsulphate treatment of seeds of the pea variety 'Parvus', a new floral mutation was isolated in the second generation. This mutation, named stamina pistilloida, is characterized by a partial fusion of the androecium with the gynoecium; the two marginal stamens of the staminal column are transformed in rudimentary carpels more or less differentiated according to ecoclimatic conditions. The genetic analysis has shown the monogenic and recessive behaviour of the mutation (gene proposed stp) and its linkage with the gene oh in the chromosome II.

Recent research in DNA repair, mutation and recombination: a report of the DNA Repair Network meeting, held at City University, London on 18 December 1995.

Science.gov (United States)

Jones, N J; Strike, P

1996-09-02

The now traditional one day Christmas DNA Repair meeting was held at City University, London for the third year in succession. With over 130 participants and a programme consisting of a total of 24 pre-offered presentations the meeting reached record dimensions. Attendees were from 24 institutions throughout the United Kingdom, and with several distinct research groups contained within the large contingents from the ICRF Clare Hall Laboratories and the MRC Cell Mutation Unit in Brighton, this indicates the increasing interest and depth of UK research in DNA repair. One slight disappointment of the meeting was the fall in the numbers of non-UK participants. Although the meeting in 1994 (Strike, 1995) saw an increase in presentations from Continental Europe (six countries including France, Germany. The Netherlands and Switzerland), the trend did not continue this year, with only Denmark being represented. The 24 contributors consisted of approximately equal numbers of postgraduate students, postdoctoral researchers and more "established' scientists reflecting the continuing policy of encouraging younger members of the repair community to present their work. The mix of presenters was particularly well illustrated by two excellent and consecutive talks by Professor Bryn Bridges (MRC Cell Mutation Unit) and Alison Mitchell, a postgraduate student in Stephen West's laboratory (ICRF, Clare Hall). The organisms under study were as equally disparate and included Archaebacteria, Escherichia coli. Saccharomyces cerevisiae, Schizosaccharomyces pombe, Aspergillus, mice and men. The range of topics was also varied and included bacterial mutagenesis, NMR studies of Ada protein, preferential DNA repair, cell cycle checkpoint genes, reconstitution of nucleotide excision repair and V(D)J recombination in vitro, creation of repair deficient transgenic mice and mismatch defects in human cells. The result was a very successful meeting which was characterized by the consistently high

Improvement of pulse crops through induced mutations: Reconstruction of plant type

International Nuclear Information System (INIS)

Rao, C.H.; Tickoo, J.L.; Ram, H.; Jain, H.K.

1975-01-01

Many species of grain legumes, because of their cultivation under marginal conditions for centuries, have retained a number of semi-wild characteristics, such as a bushy and spreading growth, which contribute to their adaptability but reduce their yields. The observations presented here indicate that induced mutations may prove effective in generating new plant-types in these crops, which are marked by an improvement in the harvest index and which will show a response to increased plant densities. The present report describes observations on the M 2 progenies of pigeon pea and mung bean on which work has been initiated. (author)

Global impact of induced mutation in plant breeding

International Nuclear Information System (INIS)

Bhatia, R.

2001-01-01

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

Study on the abnormalities in sperm and gene mutation induced by retention of 147Pm in testis

International Nuclear Information System (INIS)

Zhu Shoupeng; Lun Mingyue; Yang Shuqin

1990-05-01

The purpose of the present study is to ascertain 147 Pm retention in testis and its radiogenotoxicological effects of gene mutation through varying radioactivities of internal exposure. Especially the accumulation of 147 Pm in testis induces the dominant lethal, dominant skeletal mutation and abnormalities in sperm. Studies indicated that the cumulative absorption dose in testis increases as the internal exposure of 147 Pm increases. The internal exposure of 147 Pm can destroy the genetic materials and raise the rates of dominant lethal and dominant mutation of skeletal abnormalities in the offspring. The relationship between the rate of dominant skeletal mutation (B) and accumulated radioactivities of 147 Pm (D) in testis can be described by a linear equation that is B 20.68 + 35.48 D. The relationship between abnormalities of the sperm and the cumulative dose from 147 Pm in testis can be expressed by the following equation: S = 10.8705 D 0.5224 + 3.1768

Use of induced mutations in soybean breeding

International Nuclear Information System (INIS)

Zakri, A.H.; Jalani, B.S.; Ng, K.F.

1981-01-01

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)

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.

Mutated N-ras does not induce p19 arf in CO25 cell line | Saleh ...

African Journals Online (AJOL)

The mouse cell line (CO25) used in this study was transfected with a glucocorticoid inducible mutated human N-ras oncogene under transcriptional control of the steroid-sensitive promoter of the mouse mammary tumors virus long terminal repeat MMTV-LTR. This study was aimed to investigate the expression of p19arf and ...

Mutation breeding newsletter. No. 45

International Nuclear Information System (INIS)

2001-07-01

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

TAL effector nucleases induce mutations at a pre-selected location in the genome of primary barley transformants

DEFF Research Database (Denmark)

Wendt, Toni; Holm, Preben Bach; Starker, Colby G

2013-01-01

, and their broad targeting range. Here we report the assembly of several TALENs for a specific genomic locus in barley. The cleavage activity of individual TALENs was first tested in vivo using a yeast-based, single-strand annealing assay. The most efficient TALEN was then selected for barley transformation....... Analysis of the resulting transformants showed that TALEN-induced double strand breaks led to the introduction of short deletions at the target site. Additional analysis revealed that each barley transformant contained a range of different mutations, indicating that mutations occurred independently...

Epistatic participation of REV1 and REV3 in the formation of UV-induced frameshift mutations in cell cycle-arrested yeast cells

Energy Technology Data Exchange (ETDEWEB)

Heidenreich, Erich [Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)]. E-mail: erich.heidenreich@meduniwien.ac.at; Eisler, Herfried [Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria); Steinboeck, Ferdinand [Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)

2006-01-29

Mutations arising in times of cell cycle arrest may provide a selective advantage for unicellular organisms adapting to environmental changes. For multicellular organisms, however, they may pose a serious threat, in that such mutations in somatic cells contribute to carcinogenesis and ageing. The budding yeast Saccharomyces cerevisiae presents a convenient model system for studying the incidence and the mechanisms of stationary-phase mutation in a eukaryotic organism. Having studied the emergence of frameshift mutants after several days of starvation-induced cell cycle arrest, we previously reported that all (potentially error-prone) translesion synthesis (TLS) enzymes identified in S. cerevisiae did not contribute to the basal level of spontaneous stationary-phase mutations. However, we observed that an increased frequency of stationary-phase frameshift mutations, brought about by a defective nucleotide excision repair (NER) pathway or by UV irradiation, was dependent on Rev3p, the catalytic subunit of the TLS polymerase zeta (Pol {zeta}). Employing the same two conditions, we now examined the effect of deletions of the genes coding for polymerase eta (Pol {eta}) (RAD30) and Rev1p (REV1). In a NER-deficient strain background, the increased incidence of stationary-phase mutations was only moderately influenced by a lack of Pol {eta} but completely reduced to wild type level by a knockout of the REV1 gene. UV-induced stationary-phase mutations were abundant in wild type and rad30{delta} strains, but substantially reduced in a rev1{delta} as well as a rev3{delta} strain. The similarity of the rev1{delta} and the rev3{delta} phenotype and an epistatic relationship evident from experiments with a double-deficient strain suggests a participation of Rev1p and Rev3p in the same mutagenic pathway. Based on these results, we propose that the response of cell cycle-arrested cells to an excess of exo- or endogenously induced DNA damage includes a novel replication

Use of induced mutations in improving sorghum hybrids

Energy Technology Data Exchange (ETDEWEB)

Shashidhar, L S; Patil, S S; Goud, J V [University of Agricultural Sciences, Dharwad (India)

1990-01-01

Full text: The established male sterile line '296A' and a restorer line '5501' were mutagenised using 0.05% MMS, and the mutagenised populations were involved in the following cross combinations: 296A x 5501 (M{sub 1} and M{sub 2}), 296A (M{sub 1}) x 5501, 296A (M{sub 1}) x 5501 (M{sub 1}). The derived F{sub 1} populations of these combinations were compared with control F{sub 1} populations with respect to yield/plant. Induced mutations increased combining ability of the restorer parent as evidenced by an increase in the mean of the derived F{sub 1} populations, involving M{sub 1} and M{sub 2} populations of 5501 as males. On the contrary, the mean combining ability of 296A remained unchanged. However, variability in all these derived F{sub 1} populations was increased over that of control F{sub 1} indicating that selection can be practiced for mutants with better combining ability. (author)

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

Science.gov (United States)

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

2016-01-01

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

Mutation breeding of oil seed crops. Proceedings of a final research co-ordination meeting of an FAO/IAEA co-ordinated research programme held in Vienna, 11-15 January 1993

International Nuclear Information System (INIS)

1994-12-01

The document contains 19 papers presented at the final Research Co-ordination Meeting on 'Mutation Breeding of Oil Seed Crops' held in Vienna between 11-15 January 1993. A separate abstract was prepared for each paper. Refs, figs and tabs

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

Directory of Open Access Journals (Sweden)

Ying Shen

2014-01-01

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

Homologous leaf mutations induced in small- and large seeded lentils and their effect on some economic characters

International Nuclear Information System (INIS)

Sharma, S.K.; Sharma, B.

1978-01-01

Large-seeded 'L 1492' and small-seeded 'L 235' varieties of lentil (Lens culinaris Medic.) were treated with gamma-rays and NMU (N-nitroso-N-methyl urea.). The leaves of the 2 groups are also usually large and small respectively. Some homologous leaf mutations were isolated in both the varieties. In the small-seeded variety, leaf mutations similar to the large-seeded variety were induced and vice versa. The leaf mutations in the 2 groups did not show any change in pod or seed size. Thus the genes responsible for taxonomic differentiation of the small and large-seeded types seem to be different from those reported here, which simply modify the leaf morphology. The seed yield of all the leaf mutants was less than that of the parent varieties. (author)

The potential role of biotechnology and induced mutations in plant breeding

International Nuclear Information System (INIS)

Rubluo, A.; Brunner, I.; Palomino, G.; Rodriguez Garay, B.

2001-01-01

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

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

International Nuclear Information System (INIS)

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

1999-01-01

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

Whole-Genome Sequencing and iPLEX MassARRAY Genotyping Map an EMS-Induced Mutation Affecting Cell Competition in Drosophila melanogaster

Directory of Open Access Journals (Sweden)

Chang-Hyun Lee

2016-10-01

Full Text Available Cell competition, the conditional loss of viable genotypes only when surrounded by other cells, is a phenomenon observed in certain genetic mosaic conditions. We conducted a chemical mutagenesis and screen to recover new mutations that affect cell competition between wild-type and RpS3 heterozygous cells. Mutations were identified by whole-genome sequencing, making use of software tools that greatly facilitate the distinction between newly induced mutations and other sources of apparent sequence polymorphism, thereby reducing false-positive and false-negative identification rates. In addition, we utilized iPLEX MassARRAY for genotyping recombinant chromosomes. These approaches permitted the mapping of a new mutation affecting cell competition when only a single allele existed, with a phenotype assessed only in genetic mosaics, without the benefit of complementation with existing mutations, deletions, or duplications. These techniques expand the utility of chemical mutagenesis and whole-genome sequencing for mutant identification. We discuss mutations in the Atm and Xrp1 genes identified in this screen.

Evolution of high yielding chickpea varieties, having improved plant type and disease resistance, through induced mutations

International Nuclear Information System (INIS)

Sadiq, M.; Hussan, M.; Haq, M.A.

1989-01-01

The breeding programme on the use of induced mutations, in chickpea for genetic variability for better plant type, grain yield and disease resistance has been started. The chickpea mutant variety is one of the leading varieties being extensively grown throughout Pakistan and has played its role in stabilizing the chickpea production in the country. Four chickpea varieties were treated, each with two dosed of gamma rays. The main purpose of the mutagenic treatment of these varieties/cultivars, was induce multiple resistance. (A.B.)

Radiation-induced mutations in fish

International Nuclear Information System (INIS)

Schroeder, J.H.

1980-01-01

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 F 1 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 F 1 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 F 1 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 F 1 males with 500 R, the cohesiveness of F 1 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 F 1 generation of the seawater substrain but were unchanged in that of freshwater's. In F 2 generation the mean values of the same behavioral characters decreased in both seawater and freshwater substrains. (Nakanishi, T.)

Adaptive mutation: has the unicorn landed?

Science.gov (United States)

Foster, P L

1998-04-01

Reversion of an episomal Lac- allele during lactose selection has been studied as a model for adaptive mutation. Although recent results show that the mutations that arise during selection are not "adaptive" in the original sense, the mutagenic mechanism that produces these mutations may nonetheless be of evolutionary significance. In addition, a transient mutational state induced in a subpopulation of starving cells could provide a species with a mechanism for adaptive evolution.

Adaptive mutation: has the unicorn landed?

Science.gov (United States)

Foster, P L

1998-01-01

Reversion of an episomal Lac- allele during lactose selection has been studied as a model for adaptive mutation. Although recent results show that the mutations that arise during selection are not "adaptive" in the original sense, the mutagenic mechanism that produces these mutations may nonetheless be of evolutionary significance. In addition, a transient mutational state induced in a subpopulation of starving cells could provide a species with a mechanism for adaptive evolution. PMID:9560365

Mutation breeding in malting barley

Energy Technology Data Exchange (ETDEWEB)

Hiraki, Makoto; Sanada, Matsuyoshi

1984-03-01

The released varieties of malting barley through mutation breeding is more than ten in number, including foreign varieties. In Japan four varieties has been released so far. We started mutation breeding in 1956 together with cross breeding that we employed before. Until now, Gamma 4, Amagi Nijo 1 and Fuji Nijo 2 have been produced from the direct use of induced mutations and Nirasaki Nijo 8 from the indirect use of them. Mutation breeding has been used mainly in the partial improvement of agronomic characteristics since the selection for malting quality was very complicated. As the variety bred by induced mutation is usually equivalent to the original variety in malting quality, both this new variety and the original one could be cultivated in the same area without any problem on later malt production. Particularly when one farmer cultivates barley in an extensive acreage, he can harvest at the best time according to the different maturing time of each variety. From these points of view, mutation breeding is an efficient tool in malting barley breeding. Mutagens we have used so far are X-rays, ..gamma..-rays, neutron and chemicals such as dES. From our experience in selection, the low dose of radiation and chemical mutagens are more effective in selection of point mutation than the high dose of radiation which tends to produce many abnormal but few practical mutants. (author).

Mutations induced by X-radiation in the yeast Schizosaccharomyces pombe

International Nuclear Information System (INIS)

Loprieno, N.; Barale, R.; Baroncelli, S.; Cammellini, A.; Melani, M.; Nieri, R.; Nozzolini, M.; Rossi, A.M.; Pisa Univ.

1975-01-01

Experiments on strains of yeast with different genetic backgrounds were done to evaluate the kinetics of inactivation and mutation induction by X-radiation. A system of forward mutation induction in five loci was used and a specific mutation rate was evaluated for the wild type. From a comparison of observations with wild type and radiation-sensitive strains, it may be assumed that in this yeast, mutations are mainly the result of a repair-active process. The range of genotypic and phenotypic influence upon the specific locus mutation rate was evaluated with appropriate biological material and experiments

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)

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

IAEA specialist meeting on flow induced vibrations in fast breeder reactors, Paris, France, 22-24 October 1986

International Nuclear Information System (INIS)

Perez, M.A.

1986-10-01

The Specialists' Meeting on ''Flow Induced Vibrations in FBRs for LMFBR Applications'' was held in Paris under the auspices of the French CEA on 21-24 October 1982. The meeting was sponsored by the IAEA on the recommendation of the 14th Meeting of the IWGFR and was attended by 31 participants from France, the Federal Republic of Germany, India, Italy, Japan, the United Kingdom, the Union of Soviet Socialist Republics, the United States of America and one international organization (IAEA). The meeting was presided over by Pr. R.J. Gibert of France. After the first session on review of national positions in the subject field (7 papers), the meeting was divided into five technical sections as follows: fluid-structures interaction, calculation methods (3 papers); tubes bundles vibration and weir (4 papers); instability (6 papers); induced vibrations in the pumps (2 papers). A separate abstract was prepared for each of these papers

Induced mutations for soybean rust resistance

International Nuclear Information System (INIS)

Smutkupt, S.; Wongpiyasatid, A.; Lamseejan, S.

1983-01-01

Soybean mutation experiments for inducing rust resistance in the cultivars G 8375, Wakashima mutant number 10, Taichung N, S.J.2, S.J.4, BM 50, BM 98, G 8377, G 8586 and G 8587 have been carried out since 1979. Six pods from each of 4438 control and 43,907 M 1 plants were randomly harvested. M 2 seeds of each cultivar of different doses were bulked (M 2 bulk). In addition, 270 good M 1 plants were selected and threshed singly (M 2 single). M 2 -bulk and M 2 -single seeds were advanced to M 3 . Both, M 3 -bulk and M 3 -single plants, together with the remaining M 2 -bulk seeds were screened for rust resistance in the rainy season of 1980 in Nong Hoi Valley (altitude about 1000 m above sea level) and at Mae Joe Station, both in Chiang Mai Province (latitude 18 deg. 31'-19 deg. N). Based on the IWGSR rating system, soybean plants with slow growth of rust were selected from both locations. The results were as follows: Six plants were selected from a total of 2802 control plants, and 115 from a total of 28,834 M 2 and M 3 plants. Further evaluation of these selections for rust resistance will be carried out in the rainy season of 1981 in Nong Hoi Valley, Chiang Mai. (author)

Deletion mutations of bacteriophage

International Nuclear Information System (INIS)

Ryo, Yeikou

1975-01-01

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

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

International Nuclear Information System (INIS)

Ikeda, Fukio

1979-01-01

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.)

A Somatic HIF2α Mutation-Induced Multiple and Recurrent Pheochromocytoma/Paraganglioma with Polycythemia: Clinical Study with Literature Review.

Science.gov (United States)

Liu, Qiuli; Wang, Yan; Tong, Dali; Liu, Gaolei; Yuan, Wenqiang; Zhang, Jun; Ye, Jin; Zhang, Yao; Yuan, Gang; Feng, Qingxing; Zhang, Dianzheng; Jiang, Jun

2017-03-01

A syndrome known as pheochromocytomas (PCC)/paragangliomas (PGL) and polycythemia resulted from gain-of-function mutation of hypoxia-inducible factor 2α (HIF2α) has been reported recently. However, clinical features of this syndrome vary from patient to patient. In our study, we described the clinical features of the patient within 15-year follow-up with a literature review. The patient presented with "red face" since childhood and was diagnosed with polycythemia and pheochromocytoma in 2000, and then, tumor was removed at his age of 27 (year 2000). However, 13 years later (2013), he was diagnosed with multiple paragangliomas. Moreover, 2 years later (2015), another two paragangaliomas were also confirmed. Genetic analysis of hereditary PCC/PGL-related genes was conducted. A somatic heterozygous missense mutation of HIF2α (c.1589C>T) was identified at exon 12, which is responsible for the elevated levels of HIF2α and erythropoietin (EPO) and subsequent development of paragangaliomas. However, this mutation was only found in the tumors from three different areas, not in the blood. So far, 13 cases of PCC/PGL with polycythemia have been reported. Among them, somatic mutations of HIF2α at exon 12 are responsible for 12 cases, and only 1 case was caused by germline mutation of HIF2α at exon 9. The HIF2α mutation-induced polycythemia with PCC/PGL is a rare syndrome with no treatment for cure. Comprehensive therapies for this disease include removal of the tumors and intermittent phlebotomies; administration of medications to control blood pressure and to prevent complications or death resulted from high concentration of red blood cell (RBC). Genetic test is strongly recommended for patients with early onset of polycythemia and multiple/recurrent PCC/PGL.

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.

Study on the abnormalities in sperm and gene mutation induced by retention of {sup 147}Pm in testis

Energy Technology Data Exchange (ETDEWEB)

Shoupeng, Zhu; Mingyue, Lun; Shuqin, Yang [Suzhou Medical Coll., JS (China)

1990-05-01

The purpose of the present study is to ascertain {sup 147}Pm retention in testis and its radiogenotoxicological effects of gene mutation through varying radioactivities of internal exposure. Especially the accumulation of {sup 147}Pm in testis induces the dominant lethal, dominant skeletal mutation and abnormalities in sperm. Studies indicated that the cumulative absorption dose in testis increases as the internal exposure of {sup 147}Pm increases. The internal exposure of {sup 147}Pm can destroy the genetic materials and raise the rates of dominant lethal and dominant mutation of skeletal abnormalities in the offspring. The relationship between the rate of dominant skeletal mutation (B) and accumulated radioactivities of {sup 147}Pm (D) in testis can be described by a linear equation that is B 20.68 + 35.48 D. The relationship between abnormalities of the sperm and the cumulative dose from {sup 147}Pm in testis can be expressed by the following equation: S = 10.8705 D{sup 0.5224} + 3.1768.

Was Muller's 1946 Nobel Prize research for radiation-induced gene mutations peer-reviewed?

Science.gov (United States)

Calabrese, Edward J

2018-06-06

This historical analysis indicates that it is highly unlikely that the Nobel Prize winning research of Hermann J. Muller was peer-reviewed. The published paper of Muller lacked a research methods section, cited no references, and failed to acknowledge and discuss the work of Gager and Blakeslee (PNAS 13:75-79, 1927) that claimed to have induced gene mutation via ionizing radiation six months prior to Muller's non-data Science paper (Muller, Science 66(1699):84-87, 1927a). Despite being well acclimated into the scientific world of peer-review, Muller choose to avoid the peer-review process on his most significant publication. It appears that Muller's actions were strongly influenced by his desire to claim primacy for the discovery of gene mutation. The actions of Muller have important ethical lessons and implications today, when self-interest trumps one's obligations to society and the scientific culture that supports the quest for new knowledge and discovery.

Endurance exercise rescues progeroid aging and induces systemic mitochondrial rejuvenation in mtDNA mutator mice

Science.gov (United States)

Safdar, Adeel; Bourgeois, Jacqueline M.; Ogborn, Daniel I.; Little, Jonathan P.; Hettinga, Bart P.; Akhtar, Mahmood; Thompson, James E.; Melov, Simon; Mocellin, Nicholas J.; Kujoth, Gregory C.; Prolla, Tomas A.; Tarnopolsky, Mark A.

2011-01-01

A causal role for mitochondrial DNA (mtDNA) mutagenesis in mammalian aging is supported by recent studies demonstrating that the mtDNA mutator mouse, harboring a defect in the proofreading-exonuclease activity of mitochondrial polymerase gamma, exhibits accelerated aging phenotypes characteristic of human aging, systemic mitochondrial dysfunction, multisystem pathology, and reduced lifespan. Epidemiologic studies in humans have demonstrated that endurance training reduces the risk of chronic diseases and extends life expectancy. Whether endurance exercise can attenuate the cumulative systemic decline observed in aging remains elusive. Here we show that 5 mo of endurance exercise induced systemic mitochondrial biogenesis, prevented mtDNA depletion and mutations, increased mitochondrial oxidative capacity and respiratory chain assembly, restored mitochondrial morphology, and blunted pathological levels of apoptosis in multiple tissues of mtDNA mutator mice. These adaptations conferred complete phenotypic protection, reduced multisystem pathology, and prevented premature mortality in these mice. The systemic mitochondrial rejuvenation through endurance exercise promises to be an effective therapeutic approach to mitigating mitochondrial dysfunction in aging and related comorbidities. PMID:21368114

Non-homologous end joining dependency of {gamma}-irradiation-induced adaptive frameshift mutation formation in cell cycle-arrested yeast cells

Energy Technology Data Exchange (ETDEWEB)

Heidenreich, Erich [Institute of Cancer Research, Division of Molecular Genetics, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)]. E-mail: erich.heidenreich@meduniwien.ac.at; Eisler, Herfried [Institute of Cancer Research, Division of Molecular Genetics, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)

2004-11-22

There is a strong selective pressure favoring adaptive mutations which relieve proliferation-limiting adverse living conditions. Due to their importance for evolution and pathogenesis, we are interested in the mechanisms responsible for the formation of such adaptive, gain-of-fitness mutations in stationary-phase cells. During previous studies on the occurrence of spontaneous reversions of an auxotrophy-causing frameshift allele in the yeast Saccharomyces cerevisiae, we noticed that about 50% of the adaptive reversions depended on a functional non-homologous end joining (NHEJ) pathway of DNA double-strand break (DSB) repair. Here, we show that the occasional NHEJ component Pol4, which is the yeast ortholog of mammalian DNA polymerase lambda, is not required for adaptive mutagenesis. An artificially imposed excess of DSBs by {gamma}-irradiation resulted in a dramatic increase in the incidence of adaptive, cell cycle arrest-releasing frameshift reversions. By the use of DNA ligase IV-deficient strains we detected that the majority of the {gamma}-induced adaptive mutations were also dependent on a functional NHEJ pathway. This suggests that the same mutagenic NHEJ mechanism acts on spontaneously arising as well as on ionizing radiation-induced DSBs. Inaccuracy of the NHEJ repair pathway may extensively contribute to the incidence of frameshift mutations in resting (non-dividing) eukaryotic cells, and thus act as a driving force in tumor development.

Non-homologous end joining dependency of γ-irradiation-induced adaptive frameshift mutation formation in cell cycle-arrested yeast cells

International Nuclear Information System (INIS)

Heidenreich, Erich; Eisler, Herfried

2004-01-01

There is a strong selective pressure favoring adaptive mutations which relieve proliferation-limiting adverse living conditions. Due to their importance for evolution and pathogenesis, we are interested in the mechanisms responsible for the formation of such adaptive, gain-of-fitness mutations in stationary-phase cells. During previous studies on the occurrence of spontaneous reversions of an auxotrophy-causing frameshift allele in the yeast Saccharomyces cerevisiae, we noticed that about 50% of the adaptive reversions depended on a functional non-homologous end joining (NHEJ) pathway of DNA double-strand break (DSB) repair. Here, we show that the occasional NHEJ component Pol4, which is the yeast ortholog of mammalian DNA polymerase lambda, is not required for adaptive mutagenesis. An artificially imposed excess of DSBs by γ-irradiation resulted in a dramatic increase in the incidence of adaptive, cell cycle arrest-releasing frameshift reversions. By the use of DNA ligase IV-deficient strains we detected that the majority of the γ-induced adaptive mutations were also dependent on a functional NHEJ pathway. This suggests that the same mutagenic NHEJ mechanism acts on spontaneously arising as well as on ionizing radiation-induced DSBs. Inaccuracy of the NHEJ repair pathway may extensively contribute to the incidence of frameshift mutations in resting (non-dividing) eukaryotic cells, and thus act as a driving force in tumor development

Induced mutations for disease resistance in wheat

International Nuclear Information System (INIS)

Cerny, J.; Hanis, M.; Hanisova, A.; Knytl, V.; Sasek, A.

1983-01-01

Mutation induction has been used over a period of 20 years to obtain mutants of wheat with improved disease resistance. 34 wheat cultivars have been treated with X-rays, gamma rays, thermal neutrons or EMS. A great number of mutants were selected. Their mutational origin was verified by electrophoretic analysis of gliadin spectra. Resistances have been confirmed over several generations. None of the mutants have been released yet for commercial cultivation because of shortcomings in yield or susceptibility to other diseases. The use of mutants in cross-breeding is considered. (author)

Whole-Genome Sequencing and iPLEX MassARRAY Genotyping Map an EMS-Induced Mutation Affecting Cell Competition in Drosophila melanogaster.

Science.gov (United States)

Lee, Chang-Hyun; Rimesso, Gerard; Reynolds, David M; Cai, Jinlu; Baker, Nicholas E

2016-10-13

Cell competition, the conditional loss of viable genotypes only when surrounded by other cells, is a phenomenon observed in certain genetic mosaic conditions. We conducted a chemical mutagenesis and screen to recover new mutations that affect cell competition between wild-type and RpS3 heterozygous cells. Mutations were identified by whole-genome sequencing, making use of software tools that greatly facilitate the distinction between newly induced mutations and other sources of apparent sequence polymorphism, thereby reducing false-positive and false-negative identification rates. In addition, we utilized iPLEX MassARRAY for genotyping recombinant chromosomes. These approaches permitted the mapping of a new mutation affecting cell competition when only a single allele existed, with a phenotype assessed only in genetic mosaics, without the benefit of complementation with existing mutations, deletions, or duplications. These techniques expand the utility of chemical mutagenesis and whole-genome sequencing for mutant identification. We discuss mutations in the Atm and Xrp1 genes identified in this screen. Copyright © 2016 Lee et al.

Mutational specificity of SOS mutagenesis

International Nuclear Information System (INIS)

Kato, Takeshi

1986-01-01

In an approach to the isolation of mutants of E. coli unable to produce mutations by ultraviolet light, the author has found new umuC-mutants. Their properties could be explained by ''SOS hypothesis of Radman and Witkin'', which has now been justified by many investigators. Analysis of the umuC region of E. coli chromosome cloned in pSK 100 has led to the conclusion that two genes, umuD and umuC, having the capacity of mutation induction express in the same mechanism as that of SOS genes, which is known to be inhibited by LexA protein bonding to ''SOS box'' found at promotor region. Suppressor analysis for mutational specificity has revealed: (i) umuDC-independent mutagens, such as EMS and (oh) 4 Cy, induce selected base substitution alone; and (ii) umuDC-dependent mutagens, such as X-rays and gamma-rays, induce various types of base substitution simultaneously, although they have mutational specificity. In the umuDC-dependent processes of basechange mutagenesis, the spectra of base substitution were a mixture of base substitution reflecting the specific base damages induced by individual mutagens and nonspecific base substitution. In conclusion, base substitution plays the most important role in umuDC-dependent mutagenesis, although mutagenesis of umuDC proteins remains uncertain. (Namekawa, K.)

CRISPR Correction of a Homozygous Low-Density Lipoprotein Receptor Mutation in Familial Hypercholesterolemia Induced Pluripotent Stem Cells.

Science.gov (United States)

Omer, Linda; Hudson, Elizabeth A; Zheng, Shirong; Hoying, James B; Shan, Yuan; Boyd, Nolan L

2017-11-01

Familial hypercholesterolemia (FH) is a hereditary disease primarily due to mutations in the low-density lipoprotein receptor (LDLR) that lead to elevated cholesterol and premature development of cardiovascular disease. Homozygous FH patients (HoFH) with two dysfunctional LDLR alleles are not as successfully treated with standard hypercholesterol therapies, and more aggressive therapeutic approaches to control cholesterol levels must be considered. Liver transplant can resolve HoFH, and hepatocyte transplantation has shown promising results in animals and humans. However, demand for donated livers and high-quality hepatocytes overwhelm the supply. Human pluripotent stem cells can differentiate to hepatocyte-like cells (HLCs) with the potential for experimental and clinical use. To be of future clinical use as autologous cells, LDLR genetic mutations in derived FH-HLCs need to be corrected. Genome editing technology clustered-regularly-interspaced-short-palindromic-repeats/CRISPR-associated 9 (CRISPR/Cas9) can repair pathologic genetic mutations in human induced pluripotent stem cells. We used CRISPR/Cas9 genome editing to permanently correct a 3-base pair homozygous deletion in LDLR exon 4 of patient-derived HoFH induced pluripotent stem cells. The genetic correction restored LDLR-mediated endocytosis in FH-HLCs and demonstrates the proof-of-principle that CRISPR-mediated genetic modification can be successfully used to normalize HoFH cholesterol metabolism deficiency at the cellular level.

Tritiated uracil, tritiated thymidine, and bromodeoxyuridine induced mutations in eucaryotic cells

International Nuclear Information System (INIS)

Burki, H.J.; Moustacchi, E.; Cleaver, J.E.

1979-02-01

The induction of gene conversion at the ARG-4 locus in strain BZ34 of Saccharomyces cerevisiae was examined after the cells incorporated y- 3 H uracil under optimum growth conditions for 16 hours, and then received damage at 4 0 C from tritium decays at very low dose rates of 1.4 to 27.6 tritium decays per hour. The results were compared to the results of gene conversion induced by 60 Co. The induction of resistance to 6TG in Chinese hamster ovary (CHO) cells has been studied after incorporation of 3 H-methyl thymidine, 6- 3 H-thymidine, and bromodeoxyuridine under several experimental conditions. The induction of mutations by incorporated 6- 3 H-thymidine is about three times as effective as the induction of mutations by tritiated-methyl thymidine. These results suggest that the determination of the RBE for tritium decays in model eucaryotic systems like yeast and cultured Chinese hamster cells will be influenced by the precise experimental conditions employed. In particular, experiments with mammalian cells will be affected by hot times for mutagenesis in the cell cycle and hot positions within the DNA in the nucleus, and also by the position of tritium decay within the DNA-incorporated molecule

Induced mutations in Petunia hybrida Hort

International Nuclear Information System (INIS)

Kashikar, S.G.; Khalatkar, A.S.

1980-01-01

The seeds of a white flowering strain of Petunia hybrida hort. were treated with different concentrations of ethyl methane-sulphonate, sodium azide, diethyl sulphate, N-methyl-N'-nitro-N-nitrosoguanidine, ethylene imine and gamma radiations. A large number of flower colour and morphological mutants superior to the parental variety were obtained. The flower colour mutations took the form of sectors and whole colour changes. The latter included a large spectrum of colours from light to deep magenta, pink, purple and violet coloured petals. The anthocyanin analysis of these mutants showed different patterns of pigments responsible for the various colours. In addition to these, a broad spectrum of morphological mutations of ornamental value included dwarfs, unbranched, cristata, densa, campyloflora and velutiniflora types. The inheritance of horticulturally important characters was investigated in M 3 and M 4 generations. (author)

Radiation-induced mutations in sweet cherry (Prunus avium L.)

Energy Technology Data Exchange (ETDEWEB)

Saamin, S [Cocoa and Coconut Research Division, Malaysian Agricultural Research and Development Institute (Malaysia); Thompson, M M [Department of Horticulture, Oregon State University, Corvallis, OR (United States)

1989-01-01

Full text: Dormant scions of 'Bing' were exposed to 1-2.5 kR gamma radiation. The main buds were excised and the scions grafted to allow the growth of accessory buds into primary shoots. The frequency and types of mutations were described in a population of 3307 M{sub 1}V{sub 2} shoot. The overall mutation frequency was 2.7% incl. 0.15% growth-reduced mutants. The experiment was repeated using 3kR and 4kR fractionated doses in water. Differences in mutation frequency at 3kR and 4kR were not significant. Of 2765 surviving M{sub 1}V{sub 2} shoots derived from irradiation of accessory buds of both standard and V{sub 1} shoots, the overall mutation frequency was 3.3% incl. 1.7% partial leaf mutants, 1.0% leaf mutants, and 0.54% growth-reduced mutants. For maximum mutation rate with adequate survival we suggest acute irradiation of accessory buds in air at dosages approximating LD50. Mutant sectors in M{sub 1}V{sub 1} shoots derived from accessory buds are larger than those from main buds, as revealed by the higher number of mutant repeats. (author)

Plant mutation reports. Vol. 1, No. 1, May 2006

International Nuclear Information System (INIS)

2006-05-01

current status of induced mutations in rice germplasm enhancement, new variety development and functional genomics studies, and future perspectives of nuclear and related techniques in rice breeding and genetics. The Agency through RCA Project RAS/5/040 and National TC Projects VIE/5/014 and PAK/5/042, sponsored 15 participants. The host institute, the Institute of Radiation Breeding, National Institute of Agrobiological Resources, Japan, also invited and sponsored 5 Japanese participants. The participants presented their work on rice mutation breeding, new mutation techniques, biological basis of induced mutations, novel mutants for rice improvement and functional genomics research. Inside this issue, you will find the complete papers of some of the presentations. You will not only have an overview of the application of mutation techniques in rice breeding in these countries, but you will also be able to envision the future perspectives of nuclear techniques in rice improvement. We also included a few papers that were not presented in the meeting but are relevant to this theme and are beneficial for you to get a broader view. Based on my communications with these authors and my understanding of these papers, I got the following impressions on mutation techniques in rice improvement which I would like to share with you: (1) Mutation techniques can be successfully deployed even in institutes with limited infrastructure and laboratory facilities, a common situation in developing countries, which is a very important feature that made this technology widely accepted in almost all countries; (2) Mutation techniques have proven not only useful for improving agronomic traits, i.e., yield, plant height, growth duration, etc, but also for enhancing resistance to biotic stress such as disease and insect pests and tolerance to abiotic stress such as salinity and acidic soil; (3) Mutation techniques have also proven very useful in quality improvement, i.e. development of rice

NanoTIO2 (UV-Titan) does not induce ESTR mutations in the germline of prenatally exposed female mice

DEFF Research Database (Denmark)

Boisen, Anne Mette Zenner; Shipley, Thomas; Hougaard, Karin Sørig

2012-01-01

Particulate air pollution has been linked to an increased risk of cardiovascular disease and cancer. Animal studies have shown that inhalation of air particulates induces mutations in the male germline. Expanded simple tandem repeat (ESTR) loci in mice are sensitive markers of mutagenic effects o...

Induction of different types of mutations in yeast Saccharomyces serevisiae by γ-radiation

International Nuclear Information System (INIS)

Lyubimova, K.A.; Shvaneva, N.V.; Koltovaya, N.A.

2005-01-01

Several tester systems were used to study a wide spectrum of genetic changes induced by γ-radiation in the yeast Saccharomyces cerevisiae. The tester systems allow one to identify a loss of chromosomes, recombination (crossing over) and point mutations (frame shifts and base-pair substitutions.) Large genome changes were induced by γ-rays more efficiently than the point mutations. The dose dependence of the point mutations frequency was linear. Spontaneous and induced mutation rates per base pair corresponded with the known literature data for the same tester systems. Our finding shows that the used tester systems are not specific. They are useful for further study of mutations induced by ionizing radiation with various physical characteristics

The nature of radiation-induced mutations at the white locus of Drosophila melanogaster

International Nuclear Information System (INIS)

Pastink, A.; Schalet, A.P.; Vreeken, C.; Eeken, J.C.J.; Paradi, E.

1987-01-01

X-ray- and neutron-induced mutations at the white locus of Drosophila melanogaster were used to study the nature of radiation-induced genetic damage. Genetic analysis showed the presence of multi-locus deficiencies in 15 out of 31 X-ray mutants and in 26 out of 35 mutants induced by neutrons. The DNA from 11 X-ray and 4 neutron mutants, which were not multi-locus deficiencies, was analyzed by Southern blot-hybridization. Deletions were observed in 2 X-ray and 1 neutron mutant. In combination with cytogenetic techniques, chromosomal rearrangements affecting the white locus (translocations, inversions, etc.) were identified in 3 X-ray and in 2 neutron mutants. A hot-spot for translocation breakpoints was identified in the left arm of the third chromosome. 5 X-ray mutants, which apparently did not contain large deletions, were subjected to further analysis by the nuclease S1 protection method, after cloning of the white gene. In 4 mutants a small deletion could indeed be detected in this way. Thus it seems that by far the main part of X-ray- and neutron-induced white mutants have arisen through large changes in the white gene, especially deletions. (Auth.)

Somatic mutation in larvae of the silkworm, Bombyx mori, induced by heavy ion irradiation to diapause eggs

Energy Technology Data Exchange (ETDEWEB)

Kotani, Eiji; Furusawa, Toshiharu [Kyoto Inst. of Tech. (Japan). Faculty of Textile Science; Nagaoka, Shunji [Fujita Health Univ., Toyoake, Aichi (Japan). School of Health Sciences] [and others

2002-12-01

In order to investigate whether eggs of the black-striped strain (P{sup S}) of the silkworm, Bombyx mori, represent an appropriate model for estimating the biological effect of cosmic radiation, radiosensitivity of the eggs against X-rays and heavy ion particles was examined as ground-based experiments. The exposure of diapause eggs to X-rays or heavy ion particles resulted in somatic mutations appearing as a white spot on the black integument during larval stage. Irradiation of non-diapause eggs with X-rays demonstrated a significant difference in frequency of the mutation between fractionated and single administration doses, but no difference was observed in diapause eggs. Incidence of the mutation as induced by carbon ion beams for 15-day old eggs was higher for eggs that had been kept at 15 deg C than those kept at 25 deg C. Neon beam irradiation of diapause eggs displayed dose- and linear energy transfer (LET)-dependent effects, causing a maximal rate of the mutation at 150 keV/{mu}m. These results confirm that B. mori eggs represent valid models for estimating the biological effects of cosmic radiation. (author)

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

2016-08-05

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. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Induced mutations for disease resistance in wheat and barley

International Nuclear Information System (INIS)

Hanis, M.; Hanisova, A.; Knytl, V.; Cerny, J.; Benc, S.

1977-01-01

The induction of mutations in cultivars of wheat (Triticum aestivum), barley (Hordeum vulgare), and field beans (Phaseolus vulgaris) has been part of the breeding programme at the Plant Breeding Station at Stupice since 1960. A total of 26 cultivars or selections of winter wheat, 4 cultivars or selections of spring wheat, 2 cultivars of field beans, and 43 selections of spring barley have been treated since 1960. A total of 140 mutant lines of wheat and 37 mutant lines of barley with improved disease resistance of a race-specific type have been obtained. Several mutation programme derived cultivars have been registered in Czechoslovakia (''Diamant'', ''Ametyst'', ''Favorit'', ''Hana'', ''Rapid'', and ''Atlas'' in barley, and ''Alfa'' in field beans), but none of them is a mutation for disease resistance. A series of mutants have been used in crossing programmes. Approaches to improve the efficiency of mutation breeding for disease resistance are suggested. (author)

Biological effects of space-induced mutation on robinia pseudoacacia

International Nuclear Information System (INIS)

Yuan Cunquan; Li Yun; Lu Chao; Yang Min; Zhang Yuyao

2010-01-01

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)

PINK1 heterozygous mutations induce subtle alterations in dopamine-dependent synaptic plasticity

Science.gov (United States)

Madeo, G.; Schirinzi, T.; Martella, G.; Latagliata, E.C.; Puglisi, F.; Shen, J.; Valente, E.M.; Federici, M.; Mercuri, N.B.; Puglisi-Allegra, S.; Bonsi, P.; Pisani, A.

2014-01-01

Background Homozygous or compound heterozygous mutations in the PTEN-induced kinase 1 (PINK1) gene are causative of autosomal recessive, early onset PD. Single heterozygous mutations have been repeatedly detected in a subset of patients as well as in non-affected subjects, and their significance has long been debated. Several neurophysiological studies from non-manifesting PINK1 heterozygotes have shown the existence of neural plasticity abnormalities, indicating the presence of specific endophenotypic traits in the heterozygous state. Methods In the present study, we performed a functional analysis of corticostriatal synaptic plasticity in heterozygous PINK1 knock-out (PINK1+/−) mice by a multidisciplinary approach. Results We found that, despite a normal motor behavior, repetitive activation of cortical inputs to striatal neurons failed to induce long-term potentiation (LTP), whereas long-term depression (LTD) was normal. Although nigral dopaminergic neurons exhibited normal morphological and electrophysiological properties with normal responses to dopamine receptor activation, we measured a significantly lower dopamine release in the striatum of PINK1+/−, compared to control mice, suggesting that a decrease in stimulus-evoked dopamine overflow acts as a major determinant for the LTP deficit. Accordingly, pharmacological agents capable of increasing the availability of dopamine in the synaptic cleft restored a normal LTP in heterozygous mice. Moreover, MAO-B inhibitors rescued a physiological LTP and a normal dopamine release. Conclusions Our results provide novel evidence for striatal plasticity abnormalities even in the heterozygous disease state. These alterations might be considered an endophenotype to this monogenic form of PD, and a valid tool to characterize early disease stage and design possible disease-modifying therapies. PMID:24167038

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

International Nuclear Information System (INIS)

Amer, I.M.; Moustafa, H.A.M.; Mansour, M.F.

2009-01-01

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

Plant mutation reports, Vol. 2, No. 1, December 2008

International Nuclear Information System (INIS)

2008-12-01

The International Symposium on Induced Mutations in Plants (ISIMP) was successfully held in Vienna, Austria 12-15 August 2008. It attracted more almost 500 participants, demonstrating a broad interest in induced mutations in the plant breeding and research community. The titles of oral presentations are included in this issue. Some papers submitted to the Symposium by authors who were unable to attend the Symposium are included in this issue. In this issue, you will learn that mutations can be induced in uncommon plants using various means and utilized for various purposes. For example, Kacholam, guar and cocoyam are not widely cultivated crop species and there is very limited genetic variability, Kanakamanay, Arora et al. and Ndzana et al. reported the induction of mutations as a valuable source of genetic variability in these crops. Rice is a staple food crop and has a history of successful application of mutation techniques for its improvement; however, the virus resistant mutant varieties released in the United Republic of Tanzania, the cold tolerant mutant lines developed in Madagascar and the use of proton radiation for mutation induction in this field. The use of mutation techniques for improving tomato productivity in low water supply area, for increasing crossability and progeny fertility of mungbean crossed with its wild relative species and for investigating leaf structure in mungbean are convincing examples of the usefulness of mutation techniques

Induced mutation aiming at obtaining lodging resistance in wheat C V.Omid(Triticum Aestivum)

International Nuclear Information System (INIS)

Majd, F.; Rezazadeh, M.; Ghohari, A.

1993-01-01

Mutation breeding has been an important part breeding research for solving some of the existing problems related to wheat. A locally adopted wheat cultivar 'Omid' which is a traditionally tall wheat mostly cultivated in regions with a continental climate and is susceptible to lodging was chosen as research material. The nuclear research department for agriculture of Atomic Energy Organization of Iran initiated a mutation breeding program for creating genetic variability in wheat using this local cultivar. Seeds of this variety was irradiated with gamma radiation (50-150 Gy) to induce short straw mutants with greater lodging resistance and yield potential. from a total of about 20000 irradiated seeds 1500 plants showing promising agronomic character were isolated as potential mutants. Following progeny tests and selection 18 mutants lines entered preliminary yield trail. Further field trails at different locations gave two promising lines which are characterized by higher yield, lodging resistance and early maturity. (author). 3 tabs

Sample preparation method for induced mutation on orchid

International Nuclear Information System (INIS)

Suhaimi Musa; Sakinah Ariffin

2005-01-01

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)

Methylmethane-sulphonate and X-ray-induced mutations in the Chinese hamster hprt gene: mRNA phenotyping using polymerase chain reactions

International Nuclear Information System (INIS)

Chaudhry, M.A.; Fox, Margaret

1990-01-01

Alterations in the hprt gene of Chinese hamster cells were determined in 71 spontaneous, methylmethane sulphonate (MMS)-and X-ray induced mutants, using the Southern blot hybridization technique. To investigate the possibility of small deletions, MMS-induced mutants were studied with proves derived from exons 3 and 9 but no evidence of specific deletion of these two exons was found. The polymerase chain reaction (PCR) was used to phenotype hprt transcripts in 48 MMS, X-ray and spontaneous Chinese hamster mutants by amplifying the coding region of their cDNA. Among 22 MMS-induced mutants the message was present in 16 instances. An analysis of 20 X-ray-induced mutants showed the presence of hprt mRNA in 11 of them with five having low levels of transcription. Among six spontaneous mutants, four were negative for mRNA on standard Northern blots and in one the message was only detected after PCR amplification. Direct DNA sequencing of 10 mutants revealed the presence of base substitutions in five of them while a 7 bp deletion was found in another. No mutations were found in another four mutants, suggesting the presence of mutation outside the coding region. (author)

A challenge to mutation theory of radiation carcinogenesis

International Nuclear Information System (INIS)

Watanabe, Masami

2006-01-01

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

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)

1979-11-01

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

Spontaneous mutation by mutagenic repair of spontaneous lesions in DNA

International Nuclear Information System (INIS)

Hastings, P.J.; Quah, S.-K.; Borstel, R.C. von

1976-01-01

It is stated that strains of yeast carrying mutations in many of the steps in pathways repairing radiation-induced damage to DNA have enhanced spontaneous mutation rates. Most strains isolated because they have enhanced spontaneous mutation carry mutations in DNA repair systems. This suggests that much spontaneous mutation arises by mutagenic repair of spontaneous lesions. (author)

Induced mutation for the improvement of soybean (Glycine max L.)

International Nuclear Information System (INIS)

Asencion, A.B.; Lapade, A.G.; Grafia, A.O.; Barrida, A.C.; Veluz, A.M.; Marbella, L.J.

2004-01-01

A study on the use of gamma radiation in the induction of mutations in eight varieties of soybean was conducted. The radiosensitivity of the seeds of both local and introduced soybean varieties was determined. The effects of gamma radiation in the M1 generation were evaluated. Percentage germination was not affected by doses of 200 and 250 Gy gamma radiation in all the eight soybean varieties. No significant differences in seedling height were observed at 200 Gy and the control except for the 250 Gy in BPI-Sy4, PSB-Sy4 and PSB-Sy5. In the Vietnamese varieties, significant differences in seedling height were obtained in doses of 200, 250 Gy and the control except for the variety AKO 6. There was significant difference in plant height of mature plants between the control and treatment dose of 250 Gy in varieties DT 95 and AKO 6. Likewise, significant differences in mature plant height were noted between the control and those at 250 Gy in local varieties BPI-Sy4, PSB-Sy5 and NSIC-Sy8. The number of days to flower was not affected by gamma radiation in both the local and introduced varieties. There were significant differences in the number of pods per plant between the control and a low dose of 200 Gy in Vietnamese variety DT 96 and the local varieties PSB-Sy4, PSB-Sy5 and NSIC-Sy8. The 3 types of chlorophyll mutation induced by gamma rays in the local varieties were: chlorina, striatia,and spotted yellow. Only chlorina mutant was induced in the introduced varieties. Desirable mutants that are early and high yielding were selected. Results of the drought tolerance tests indicated that the number of days to flowering of the control and 8 varieties was not affected by the duration of irrigation withdrawals 20,30,40 and 50 days after planting. Significant differences in seed weight among the different varieties were noted only in 20 and 30 day irrigation withdrawal treatment. When the effects of the different treatments were analyzed on a per variety bases, some of the

The use of radiations to induce useful mutations in fruit trees

International Nuclear Information System (INIS)

Donini, B.

1976-01-01

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)

An Alzheimer Disease-linked Rare Mutation Potentiates Netrin Receptor Uncoordinated-5C-induced Signaling That Merges with Amyloid β Precursor Protein Signaling.

Science.gov (United States)

Hashimoto, Yuichi; Toyama, Yuka; Kusakari, Shinya; Nawa, Mikiro; Matsuoka, Masaaki

2016-06-03

A missense mutation (T835M) in the uncoordinated-5C (UNC5C) netrin receptor gene increases the risk of late-onset Alzheimer disease (AD) and also the vulnerability of neurons harboring the mutation to various insults. The molecular mechanisms underlying T835M-UNC5C-induced death remain to be elucidated. In this study, we show that overexpression of wild-type UNC5C causes low-grade death, which is intensified by an AD-linked mutation T835M. An AD-linked survival factor, calmodulin-like skin protein (CLSP), and a natural ligand of UNC5C, netrin1, inhibit this death. T835M-UNC5C-induced neuronal cell death is mediated by an intracellular death-signaling cascade, consisting of death-associated protein kinase 1/protein kinase D/apoptosis signal-regulating kinase 1 (ASK1)/JNK/NADPH oxidase/caspases, which merges at ASK1 with a death-signaling cascade, mediated by amyloid β precursor protein (APP). Notably, netrin1 also binds to APP and partially inhibits the death-signaling cascade, induced by APP. These results may provide new insight into the amyloid β-independent pathomechanism of AD. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

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

International Nuclear Information System (INIS)

Correa-Victoria, F.J.

2001-01-01

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

Mutation breeding in jute

International Nuclear Information System (INIS)

Joshua, D.C.

1980-01-01

Mutagenic studies in jute in general dealt with the morphological abnormalities of the M 1 generation in great detail. Of late, induction of a wide spectrum of viable mutations have been reported in different varieties of both the species. Mutations affecting several traits of agronomic importance such as, plant height, time of flowering, fibre yield and quality, resistance to pests and diseases are also available. Cytological analysis of a large collection of induced mutants resulted in the isolation of seven trisomics in an olitorius variety. Several anatomical parameters which are the components of fibre yield, have also received attention. Some mutants with completely altered morphology were used for interpreting the evolution of leaf shape in Tiliaceas and related families. A capsularis variety developed using mutation breeding technique has been released for cultivation. Several others, including derivatives of inter-mutant hybridization have been found to perform well at different locations in the All India Coordinated Trials. Presently, chemical mutagenesis and induction of mutants of physiological significance are receiving considerable attention. The induced variability is being used in genetic and linkage studies. (author)

Transfection with extracellularly UV-damaged DNA induces human and rat cells to express a mutator phenotype towards parvovirus H-1

International Nuclear Information System (INIS)

Dinsart, C.; Cornelis, J.J.; Klein, B.; van der Eb, A.J.; Rommelaere, J.

1984-01-01

Human and rat cells transfected with UV-irradiated linear double-stranded DNA from calf thymus displayed a mutator activity. This phenotype was identified by growing a lytic thermosensitive single-stranded DNA virus (parvovirus H-1) in those cells and determining viral reversion frequencies. Likewise, exogenous UV-irradiated closed circular DNAs, either double-stranded (simian virus 40) or single-stranded (phi X174), enhanced the ability of recipient cells to mutate parvovirus H-1. The magnitude of mutator activity expression increased along with the number of UV lesions present in the inoculated DNA up to a saturation level. Unirradiated DNA displayed little inducing capacity, irrespective of whether it was single or double stranded. Deprivation of a functional replication origin did not impede UV-irradiated simian virus 40 DNA from providing rat and human cells with a mutator function. Our data suggest that in mammalian cells a trans-acting mutagenic signal might be generated from UV-irradiated DNA without the necessity for damaged DNA to replicate

Experimental mutations in soybean and their selection value

International Nuclear Information System (INIS)

Sichkar', V.I.

1979-01-01

Efficiency of widely used chemical mutagens and gamma irradiation in inducing chlorophyll changes in some soya varieties has been compared in order to further specify the relationship between this type of mutations and other morphological changes. The most active mutations found were NMU, NEU, EI and gamma radiation. The frequency of chrolophyll changes depended on the mutagen concentration and soya variety and varied from 1.58% to 19.04%. EO, NDMM and DMS produced 4-5 times lower yield of chlorophyll mutations. The following mutagen concentrations for the varieties studied were found optimum (in per cent): NMU - 0.0125, NEU - 0.025, EI - 0.03, EO - 0.05, NDMM - 0.0O625, DMS - 0.02. No relationship between the dose of gamma radiation and the mutation frequency was found. Varieties of VNIIMK 9186 and Lanka were the most mutable, 89-10 hybrid showed very low mutability. Mutagens that induced high frequency of mutations also gave the broadest spectrum of changes. Most frequent changes were xantha, lutescens and xanthaterminalis. Very few mutations from green color to white one were isolated

Mutation induction by ion beams in higher plants

Energy Technology Data Exchange (ETDEWEB)

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

2003-04-01

This review mainly describes study results obtained in the Takasaki ion-beam (IB) irradiation facility (TIARA) on the mutation induction in higher plants. Biological effects like lethality and on budding of IBs (carbon, Ne and Ar) are discussed in relation with their linear energy transfer (LET), relative biological effectiveness and the developmental states in shepherd's-purse and tobacco. Induced mutation by IB are characterized by those findings that the mutation rate by C beam is 1.9 x 10{sup -6}, being 17 times higher than the electron beam, in the shepherd's-purse, that C beam induces larger structural changes than electron beam when examined by molecular mechanism of tt and gl gene mutations, and that mutation spectrum of IB is different from that of {gamma}-ray and is wider. Novel mutants are described on shepherd's-purse (pigment mutants, ultraviolet (UV)-resistant and sensitive ones, and flowering ones), disease-resistant rice, barley and tobacco plants, and flowering plants. IB mutation is possibly useful for solving the problems of environment and foods in future. (N.I.)

In-vitro mutation breeding technology in maize

International Nuclear Information System (INIS)

Nesticky, M.

1988-08-01

Gamma-irradiation and in-vitro culture, separately or combined, as a tool for inducing mutation in maize were evaluated. This type of research has been hampered in maize because (i) maize is a cross pollinating crop and highly heterozygous and (ii) embryogenesis and plant regeneration of plants from in-vitro culture have been difficult. In the present study, carefully designed and elaborated experiments were conducted using an inbred line CH1 31 which is capable of somatic embryogenesis for the subject of mutagenesis and another line Bu 8Ro 2 for the test cross partner. Results showed: 1) Both the regeneration of plants from in-vitro culture and gamma-irradiation induced a similar spectrum of morphological variation. Although the variation with somaclones was more frequent that radiation induced mutations under the conditions used, combination of explant irradiation and in-vitro culture gave the highest frequencies of genetic variation. 2) Some of the mutations in quantitative characters can be recogned in heterozygous state. 3) Mutation can cause variation in combining ability (extent of heterosis). 4) Efficiency at embryogenesis differs with genotypes of maize. 3 refs, 11 figs, 4 tabs

In vitro technology for mutation breeding

International Nuclear Information System (INIS)

1986-10-01

The ultimate aim of the Co-ordinated Research Programme on In Vitro Technology for Mutation Breeding is to provide new effective tools for plant breeders to construct new cultivars, thus increasing agricultural production of food, feed and industrial raw material, particularly in developing countries. The participants of the research co-ordination meetings considered the potential of new advances of agricultural biotechnology, especially the use of in vitro techniques for mutation breeding. They discussed and co-ordinated plans in conjunction with the impact on plant breeding of novel technologies, such as use of somaclonal variation, cell hybridization and molecular genetics

Genetic Correction of Induced Pluripotent Stem Cells From a Deaf Patient With MYO7A Mutation Results in Morphologic and Functional Recovery of the Derived Hair Cell-Like Cells.

Science.gov (United States)

Tang, Zi-Hua; Chen, Jia-Rong; Zheng, Jing; Shi, Hao-Song; Ding, Jie; Qian, Xiao-Dan; Zhang, Cui; Chen, Jian-Ling; Wang, Cui-Cui; Li, Liang; Chen, Jun-Zhen; Yin, Shan-Kai; Huang, Tao-Sheng; Chen, Ping; Guan, Min-Xin; Wang, Jin-Fu

2016-05-01

The genetic correction of induced pluripotent stem cells (iPSCs) induced from somatic cells of patients with sensorineural hearing loss (caused by hereditary factors) is a promising method for its treatment. The correction of gene mutations in iPSCs could restore the normal function of cells and provide a rich source of cells for transplantation. In the present study, iPSCs were generated from a deaf patient with compound heterozygous MYO7A mutations (c.1184G>A and c.4118C>T; P-iPSCs), the asymptomatic father of the patient (MYO7A c.1184G>A mutation; CF-iPSCs), and a normal donor (MYO7A(WT/WT); C-iPSCs). One of MYO7A mutation sites (c.4118C>T) in the P-iPSCs was corrected using CRISPR/Cas9. The corrected iPSCs (CP-iPSCs) retained cell pluripotency and normal karyotypes. Hair cell-like cells induced from CP-iPSCs showed restored organization of stereocilia-like protrusions; moreover, the electrophysiological function of these cells was similar to that of cells induced from C-iPSCs and CF-iPSCs. These results might facilitate the development of iPSC-based gene therapy for genetic disorders. Induced pluripotent stem cells (iPSCs) were generated from a deaf patient with compound heterozygous MYO7A mutations (c.1184G>A and c.4118C>T). One of the MYO7A mutation sites (c.4118C>T) in the iPSCs was corrected using CRISPR/Cas9. The genetic correction of MYO7A mutation resulted in morphologic and functional recovery of hair cell-like cells derived from iPSCs. These findings confirm the hypothesis that MYO7A plays an important role in the assembly of stereocilia into stereociliary bundles. Thus, the present study might provide further insight into the pathogenesis of sensorineural hearing loss and facilitate the development of therapeutic strategies against monogenic disease through the genetic repair of patient-specific iPSCs. ©AlphaMed Press.

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

International Nuclear Information System (INIS)

Shen Jinjuan; Liu Yihua; Zhang Zhaorong; Ran Guangkui; Zhao Shouzhong; Xiao Li

2012-01-01

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)

Mutation induction by heavy ions

Science.gov (United States)

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

1994-10-01

Mutation induction by heavy ions is compared in yeast and mammalian cells. Since mutants can only be recovered in survivors the influence of inactivation cross sections has to be taken into account. It is shown that both the size of the sensitive cellular site as well as track structure play an important role. Another parameter which influences the probability of mutation induction is repair: Contrary to naive assumptions primary radiation damage does not directly lead to mutations but requires modification to reconstitute the genetic machinery so that mutants can survive. The molecular structure of mutations was analyzed after exposure to deuterons by amplification with the aid of polymerase chain reaction. The results-although preliminary-demonstrate that even with densely ionizing particles a large fraction does not carry big deletions which suggests that point mutations may also be induced by heavy ions.

Phonic and induced level of mutations and mutagenicity in bioorganisms habitating in the environs of Ignalina APP

International Nuclear Information System (INIS)

Lekevichius, R.; Morkunas, V.; Knabikas, A.

1992-01-01

The investigation of the extracts from the water, mud and hydrobionts of the lake Drukshiai before the construction of the Ignalina atomic power plant (1982-1984) and after its construction enabled to detect the moment of the build-up of mutagens in the hydrobionts (in 1986), when the extracts began to induce spot mutations in Salmonella typhimurium and exchanges of sister chromatids in human leukocytes in vitro. The mutagenicity of rain water, sewerage water and water from the cooler of the atomic power plant to drosophila and Salmonella typhimurium has been detected. The increments of mutations in the populations of Larus ridibundus and Microtus arvalis inhabiting the surroundings of the atomic power plant has not been noticed. (author). 4 figs., 4 refs

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

International Nuclear Information System (INIS)

Kang, C.W.

2001-01-01

''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 F 1 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 NaN 3 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 NaN 3 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 NaN 3 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

Mutation directional selection sheds light on prion pathogenesis

International Nuclear Information System (INIS)

Shen, Liang; Ji, Hong-Fang

2011-01-01

Highlights: → Most pathogenic mutations possess strong directional selection, i.e., enhancing hydrophobicity or decreasing negative and increasing positive charge. → Mutation-induced changes may strengthen the interactions between PrP and facilitating factors. → The findings also have significant implications for exploring potential regions involved in the conformational transition from PrP C to PrP Sc . -- Abstract: As mutations in the PRNP gene account for human hereditary prion diseases (PrDs), it is crucial to elucidating how these mutations affect the central pathogenic conformational transition of normal cellular prion protein (PrP C ) to abnormal scrapie isoform (PrP Sc ). Many studies proposed that these pathogenic mutations may make PrP more susceptible to conformational change through altering its structure stability. By evaluating the most recent observations regarding pathogenic mutations, it was found that the pathogenic mutations do not exert a uniform effect on the thermodynamic stability of the human PrP's structure. Through analyzing the reported PrDs-related mutations, we found that 25 out of 27 mutations possess strong directional selection, i.e., enhancing hydrophobicity or decreasing negative and increasing positive charge. Based on the triggering role reported by previous studies of facilitating factors in PrP C conversion, e.g., lipid and polyanion, we proposed that the mutation-induced changes may strengthen the interaction between PrP and facilitating factors, which will accelerate PrP conversion and cause PrDs.

Mutation directional selection sheds light on prion pathogenesis

Energy Technology Data Exchange (ETDEWEB)

Shen, Liang [Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Shandong University of Technology, Zibo 255049 (China); Ji, Hong-Fang, E-mail: jhf@sdut.edu.cn [Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Shandong University of Technology, Zibo 255049 (China)

2011-07-01

Highlights: {yields} Most pathogenic mutations possess strong directional selection, i.e., enhancing hydrophobicity or decreasing negative and increasing positive charge. {yields} Mutation-induced changes may strengthen the interactions between PrP and facilitating factors. {yields} The findings also have significant implications for exploring potential regions involved in the conformational transition from PrP{sup C} to PrP{sup Sc}. -- Abstract: As mutations in the PRNP gene account for human hereditary prion diseases (PrDs), it is crucial to elucidating how these mutations affect the central pathogenic conformational transition of normal cellular prion protein (PrP{sup C}) to abnormal scrapie isoform (PrP{sup Sc}). Many studies proposed that these pathogenic mutations may make PrP more susceptible to conformational change through altering its structure stability. By evaluating the most recent observations regarding pathogenic mutations, it was found that the pathogenic mutations do not exert a uniform effect on the thermodynamic stability of the human PrP's structure. Through analyzing the reported PrDs-related mutations, we found that 25 out of 27 mutations possess strong directional selection, i.e., enhancing hydrophobicity or decreasing negative and increasing positive charge. Based on the triggering role reported by previous studies of facilitating factors in PrP{sup C} conversion, e.g., lipid and polyanion, we proposed that the mutation-induced changes may strengthen the interaction between PrP and facilitating factors, which will accelerate PrP conversion and cause PrDs.

Induced mutations for crop improvement

International Nuclear Information System (INIS)

Micke, A.; Donini, B.; Maluszynski, M.

1990-01-01

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

Clinical and molecular analysis of a four-generation Chinese family with aminoglycoside-induced and nonsyndromic hearing loss associated with the mitochondrial 12S rRNA C1494T mutation

International Nuclear Information System (INIS)

Wang Qiuju; Li Qingzhong; Han Dongyi; Zhao Yali; Zhao Lidong; Qian Yaping; Yuan Hu; Li Ronghua; Zhai Suoqiang; Young Wieyen; Guan Minxin

2006-01-01

We report here the clinical, genetic, and molecular characterization of a four-generation Chinese family with aminoglycoside-induced and nonsyndromic hearing loss. Five of nine matrilineal relatives had aminoglycoside-induced hearing loss. These matrilineal relatives exhibited variable severity and audiometric configuration of hearing impairment, despite sharing some common features: being bilateral and having sensorineural hearing impairment. Sequence analysis of mitochondrial DNA (mtDNA) in the pedigree identified 16 variants and the homoplasmic 12S rRNA C1494T mutation, which was associated with hearing loss in the other large Chinese family. In fact, the occurrence of the C1494T mutation in these genetically unrelated pedigrees affected by hearing impairment strongly indicated that this mutation is involved in the pathogenesis of aminoglycoside-induced and nonsyndromic hearing loss. However, incomplete penetrance of hearing loss indicated that the C1494T mutation itself is not sufficient to produce a clinical phenotype but requires the involvement of modifier factors for the phenotypic expression. Those mtDNA variants, showing no evolutional conservation, may not have a potential modifying role in the pathogenesis of the C1494T mutation. However, nuclear background seems to contribute to the phenotypic variability of matrilineal relatives in this family. Furthermore, aminoglycosides modulate the expressivity and penetrance of deafness associated with the C1494T mutation in this family

Hypothesizing an ancient Greek origin of the GJB2 35delG mutation: can science meet history?

Science.gov (United States)

Kokotas, Haris; Grigoriadou, Maria; Villamar, Manuela; Giannoulia-Karantana, Aglaia; del Castillo, Ignacio; Petersen, Michael B

2010-04-01

One specific mutation of the GJB2 gene that encodes the connexin 26 protein, the 35delG mutation, has become a major interest among scientists who focus on the genetics of nonsyndromic hearing loss. The mutation accounts for the majority of GJB2 mutations detected in Caucasian populations and represents one of the most frequent disease mutations identified so far. The debate was so far between the arguments whether or not the 35delG mutation constitutes a mutational hot-spot or a founder effect; however, it was recently clarified that the latter seems the most likely. In an attempt to explore the origin and propagation of the 35delG mutation, several groups have reported the prevalence of the mutation and the carrier rates in different populations worldwide. It is now certain that the theory of a common founder prevails and that the highest carrier frequencies of the 35delG mutation are observed in southern European populations, giving rise to a discussion regarding the origin of the 35delG mutation. In this study, we discuss data previously published by our and other groups and also compare the haplotype distribution of the mutation in southern Europe, trying to understand the pathways of science and history and the conflict between them.

Effect of uvs1, uvs2 and xrs mutations on the radiosensitivity and the induced mitotic recombination frequency in diploid yeast cells

International Nuclear Information System (INIS)

Suslova, N.G.; Fedorova, I.V.; Zheleznyakova, N.Yu.

1975-01-01

The influence of the loci of radiosensitivity uvs1, uvs2, and xrs in the homozygous state at the diploid level on the sensitivity to UV and ionizing radiation and induced mitotic recombination was studied in the yeast Sacch. cerevisiae. Hypersensitivity to UV irradiation was detected in the diploids uvs2 uvs2 xrs xrs in comparision with the corresponding control. The diploid uvs1 uvs1 uvs2 uvs2 does not differ in UV sensitivity from the diploid uvs1 uvs1 UVS2 UVS2. These facts demonstrate that the uvs1 and uvs2 mutations, on the one hand, and the xrs mutations, on the other, normally control different pathways of elimination of UV-induced damages. It was shown that the diploid uvs2 uvs2 xrs3 xrs3 is far more sensitive to the lethal action of x rays than the control diploid UVS2 UVS2 xrs3 xrs3. Consequently, the mutations uvs2 and xrs3 block different modes of repair of damages induced by ionizing radiation. In all the double-mutant diploids, the frequency of mitotic recombination induced by UV rays increases sharply in comparison with that of the radioresistant diploids UVS UVS XRS XRS and the UV-sensitive diploids uvs2 uvs2 XRS XRS. Possible causes of the observed phenomenon are discussed. It was established that in a diploid homozygous for the loci uvs2 xrs5, the frequency of mitotic recombination induced by x rays increases extremely sharply. This fact confirms the hypothesis that the gene product of the locus uvs2 participates in the repair of DNA after the action of ionizing radiation. (author)

CHARACTERIZATION OF ENU-INDUCED MUTATIONS IN RED BLOOD CELL STRUCTURAL PROTEINS

Directory of Open Access Journals (Sweden)

Katrina Kildey

2013-03-01

Full Text Available Murine models with modified gene function as a result of N-ethyl-N-nitrosourea (ENU mutagenesis have been used to study phenotypes resulting from genetic change. This study investigated genetic factors associated with red blood cell (RBC physiology and structural integrity that may impact on blood component storage and transfusion outcome. Forward and reverse genetic approaches were employed with pedigrees of ENU-treated mice using a homozygous recessive breeding strategy. In a “forward genetic” approach, pedigree selection was based upon identification of an altered phenotype followed by exome sequencing to identify a causative mutation. In a second strategy, a “reverse genetic” approach based on selection of pedigrees with mutations in genes of interest was utilised and, following breeding to homozygosity, phenotype assessed. Thirty-three pedigrees were screened by the forward genetic approach. One pedigree demonstrated reticulocytosis, microcytic anaemia and thrombocytosis. Exome sequencing revealed a novel single nucleotide variation (SNV in Ank1 encoding the RBC structural protein ankyrin-1 and the pedigree was designated Ank1EX34. The reticulocytosis and microcytic anaemia observed in the Ank1EX34 pedigree were similar to clinical features of hereditary spherocytosis in humans. For the reverse genetic approach three pedigrees with different point mutations in Spnb1 encoding RBC protein spectrin-1β, and one pedigree with a mutation in Epb4.1, encoding band 4.1 were selected for study. When bred to homozygosity two of the spectrin-1β pedigrees (a, b demonstrated increased RBC count, haemoglobin (Hb and haematocrit (HCT. The third Spnb1 mutation (spectrin-1β c and mutation in Epb4.1 (band 4.1 did not significantly affect the haematological phenotype, despite these two mutations having a PolyPhen score predicting the mutation may be damaging. Exome sequencing allows rapid identification of causative mutations and development of

Mutation breeding in peas

Energy Technology Data Exchange (ETDEWEB)

Jaranowski, J [Institute of Genetics and Plant Breeding, Academy of Agriculture, Poznan (Poland); Micke, A [Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development, International Atomic Energy Agency, Vienna (Austria)

1985-02-01

The pea as an ancient crop plant still today has wide uses and is an import source of food protein. It is also an important object for genetic studies and as such has been widely used in mutation induction experiments. However, in comparison with cereals this ancient crop plant (like several other grain legumes) has gained relatively little from advances in breeding. The review focuses on the prospects of genetic improvement of pea by induced mutations, discusses principles and gives methodological information. (author)

Mutation breeding in peas

International Nuclear Information System (INIS)

Jaranowski, J.; Micke, A.

1985-01-01

The pea as an ancient crop plant still today has wide uses and is an import source of food protein. It is also an important object for genetic studies and as such has been widely used in mutation induction experiments. However, in comparison with cereals this ancient crop plant (like several other grain legumes) has gained relatively little from advances in breeding. The review focuses on the prospects of genetic improvement of pea by induced mutations, discusses principles and gives methodological information. (author)

Mutations induced by ultraviolet radiation affecting virulence in Puccinia striiformis

International Nuclear Information System (INIS)

Shang Hongsheng; Jing Jinxue; Li Zhenqi

1994-01-01

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

Coordinated Changes in Mutation and Growth Rates Induced by Genome Reduction

Directory of Open Access Journals (Sweden)

Issei Nishimura

2017-07-01

Full Text Available Genome size is determined during evolution, but it can also be altered by genetic engineering in laboratories. The systematic characterization of reduced genomes provides valuable insights into the cellular properties that are quantitatively described by the global parameters related to the dynamics of growth and mutation. In the present study, we analyzed a small collection of W3110 Escherichia coli derivatives containing either the wild-type genome or reduced genomes of various lengths to examine whether the mutation rate, a global parameter representing genomic plasticity, was affected by genome reduction. We found that the mutation rates of these cells increased with genome reduction. The correlation between genome length and mutation rate, which has been reported for the evolution of bacteria, was also identified, intriguingly, for genome reduction. Gene function enrichment analysis indicated that the deletion of many of the genes encoding membrane and transport proteins play a role in the mutation rate changes mediated by genome reduction. Furthermore, the increase in the mutation rate with genome reduction was highly associated with a decrease in the growth rate in a nutrition-dependent manner; thus, poorer media showed a larger change that was of higher significance. This negative correlation was strongly supported by experimental evidence that the serial transfer of the reduced genome improved the growth rate and reduced the mutation rate to a large extent. Taken together, the global parameters corresponding to the genome, growth, and mutation showed a coordinated relationship, which might be an essential working principle for balancing the cellular dynamics appropriate to the environment.

Mutation breeding in ornamental plants

International Nuclear Information System (INIS)

Datta, S.K.

1990-01-01

Full text: Mutation induction produced a large number of new promising varieties in ornamental species. 37 new mutants of Chrysanthemum and 14 of rose have been developed by mutations and released for commercialisation. The mutations in flower colour/shape were detected as chimeras in M 1 V 1 , M 1 V 2 , M 1 V 3 generations. The mutation frequency varied with the cultivar and exposure to gamma rays. Comparative analysis of original cultivars and their respective induced mutants on cytomorphological, anatomical and biochemical characters are being carried out for better understanding of the mechanism involved in the origin and evolution of somatic flower colour/shape mutations. Cytological analysis with reference to chromosomal aberrations, chromosome number, ICV, INV and DNA content gave no differences between the original and mutant cultivars. Analysis of florets/petal pigments by TLC and spectrophotometric methods indicated both qualitative and quantitative changes. (author)

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

International Nuclear Information System (INIS)

Moryia, M.; Takeshita, M.; Johnson, F.; Peden, K.; Will, S.; Grollman, A.P.

1988-01-01

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 32 P-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

The carcinogenic air pollutant 3-nitrobenzanthrone induces GC to TA transversion mutations in human p53 sequences.

Science.gov (United States)

vom Brocke, Jochen; Krais, Annette; Whibley, Catherine; Hollstein, Monica C; Schmeiser, Heinz H

2009-01-01

3-Nitrobenzanthrone (3-NBA) is a potent mutagen and a suspected human carcinogen present in particulate matter of diesel exhaust and ambient air pollution. Employing an assay with human p53 knock-in (Hupki) murine embryonic fibroblasts (HUFs), we examined p53 mutations induced by 3-NBA and its active metabolite, N-hydroxy-3-aminobenzanthrone (N-OH-3-ABA). Twenty-nine immortalized cultures (cell lines) from 89 HUF primary cultures exposed at passage 1 for 5 days to 2 microM 3-NBA harboured 22 different mutations in the human DNA-binding domain sequence of the Hupki p53 tumour suppressor gene. The most frequently observed mutation was GC to TA transversion (46%), corroborating previous mutation studies with 3-NBA, and consistent with the presence of persistent 3-NBA-guanosine adducts found in DNA of exposed rodents. Six of the transversions found solely in 3-NBA-treated HUFs have not been detected thus far in untreated HUFs, but have been found repeatedly in human lung tumours. (32)P-post-labelling adduct analysis of DNA from HUF cells treated with 2 microM 3-NBA for 5 days showed a pattern similar to that found in vivo, indicating the metabolic competence of HUF cells to metabolize 3-NBA to electrophilic intermediates. Total DNA binding was 160 +/- 56 per 10(7) normal nucleotides with N(2)-guanosine being the major adduct. In contrast, identical treatment with N-OH-3-ABA resulted in a 100-fold lower level of specific DNA adducts and no carcinogen-specific mutation pattern in the Hupki assay. This indicates that the level of DNA adduct formation by the mutagen is critical to obtain specific mutation spectra in the assay. Our results are consistent with previous experiments in Muta Mouse and are compatible with the possibility that diesel exhaust exposure contributes to mutation load in humans and to lung cancer risk.

Mutation induction by ion beams in plants

International Nuclear Information System (INIS)

Tanaka, Atsushi

2001-01-01

The effect of ion beams such as C, He, and Ne ions was investigated on the mutation induction in plants with the expectation that ion beams of high linear energy transfer (LET) can frequently produce large DNA alternation such as inversion, translocation and large deletion rather than point mutation. Mutation frequency was investigated using Arabidopsis visible phenotype loci and was 8 to 33 fold higher for 220 MeV carbon ions than for electrons. Mutation spectrum was investigated on the flower color of chrysanthemum cv to find that flower mutants induced by ion beams show complex and stripe types rather than single color. Polymerase chain reaction analysis was performed to investigate DNA alteration of mutations. In conclusion, the characteristics of ion beams for the mutation induction are 1) high frequency, 2) broad mutation spectrum, and 3) novel mutants. (S. Ohno)

Mutation induction by ion beams in plants

Energy Technology Data Exchange (ETDEWEB)

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

2001-03-01

The effect of ion beams such as C, He, and Ne ions was investigated on the mutation induction in plants with the expectation that ion beams of high linear energy transfer (LET) can frequently produce large DNA alternation such as inversion, translocation and large deletion rather than point mutation. Mutation frequency was investigated using Arabidopsis visible phenotype loci and was 8 to 33 fold higher for 220 MeV carbon ions than for electrons. Mutation spectrum was investigated on the flower color of chrysanthemum cv to find that flower mutants induced by ion beams show complex and stripe types rather than single color. Polymerase chain reaction analysis was performed to investigate DNA alteration of mutations. In conclusion, the characteristics of ion beams for the mutation induction are 1) high frequency, 2) broad mutation spectrum, and 3) novel mutants. (S. Ohno)

Mutation breeding newsletter. No. 43

International Nuclear Information System (INIS)

1997-10-01

This issue of the Newsletter includes articles dealing with radiation induced mutation based plant breeding research findings aimed at improving productivity, disease resistance and tolerance of stress conditions

Utilization of radiations in mutation breeding of tuber crops

International Nuclear Information System (INIS)

Kukimura, H.

1981-01-01

Most of the tuber crops are vegetatively propagated and their spontaneous mutations have been constructively utilized to practical farming. Significance of utilization of mutations to breeding should not be overlooked, since mutation can be articially induced by various mutagenic agents. In tuber crops, ionizing radiations are mostly applied to induce mutations. Radiosensitivity varies with species, genotypes and organs. For the purpose of mutation induction, 10-20 kR of gamma-rays is given to tubers and/or shoots in sweet potato and 2-10 kR in potato. It should be noted that radiation damage is more or less transmissible to later vegetative generations. A useful characters in practical agriculture, following mutations have been obtained so far: skin colour, short stemmed, changes in dry matter content, total sugars content and tuber yield, earlier maturity and sculf resistance in sweet potato. And, skin colour, changes in starch content and stolon length, day-neutral tuberization and cyst-nematode resistance in potato. Apart from mutations, radiation can be utilized for breaking down the incompatibility in sweet potato. Promising mutant clones with probable release in Japan are Kyushu 78 of sweet potato and Koniku 16 and Konkei 55 of potato. (author)

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

Science.gov (United States)

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

2013-06-01

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

Mutation breeding in crop improvement - achievements and prospects

International Nuclear Information System (INIS)

Kharkwal, M.C.

2004-01-01

Crop improvement programmes through induced mutations were initiated about seven decades ago. Majority of the mutant varieties have been released during the last two decades. In terms of the development and release of mutant varieties, China (605), India (309), Russia (204), the Netherlands (176), USA (125) and Japan (120) are the leading countries. Radiation, especially gamma radiation was the most frequently used mutagen for inducing mutations in crop plants. Out of 1072 mutant varieties of cereals, rice alone accounts for 434 varieties followed by barley (269). Mutation breeding has made significant contribution in increasing the production of rice, ground nut, castor, chickpea, mungbean and urd bean in the Indian subcontinent. The future mutation breeding programmes should be aimed at improving the root characters, nodulation in legumes, alteration of fatty acid composition in oil seeds, host pathogen interactions, photo- insensitivity and apomixix in crop plants

Mutation breeding in pepper

International Nuclear Information System (INIS)

Daskalov, S.

1986-01-01

Pepper (Capsicum sp.) is an important vegetable and spice crop widely grown in tropical as well as in temperate regions. Until recently the improvement programmes were based mainly on using natural sources of germ plasma, crossbreeding and exploiting the heterosis of F 1 hybrids. However, interest in using induced mutations is growing. A great number of agronomically useful mutants as well as mutants valuable for genetic, cytological and physiological studies have been induced and described. In this review information is presented about suitable mutagen treatment procedures with radiation as well as chemicals, M 1 effects, handling the treated material in M 1 , M 2 and subsequent generations, and mutant screening procedures. This is supplemented by a description of reported useful mutants and released cultivars. Finally, general advice is given on when and how to incorporate mutation induction in Capsicum improvement programmes. (author)

Mutation breeding newsletter. No. 20

Energy Technology Data Exchange (ETDEWEB)

NONE

1982-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 17

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 16

Energy Technology Data Exchange (ETDEWEB)

NONE

1980-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 8

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-09-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 12

Energy Technology Data Exchange (ETDEWEB)

NONE

1978-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 10

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 32

Energy Technology Data Exchange (ETDEWEB)

NONE

1988-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 18

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 9

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-01-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 22

Energy Technology Data Exchange (ETDEWEB)

NONE

1983-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 15

Energy Technology Data Exchange (ETDEWEB)

NONE

1980-02-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 9

International Nuclear Information System (INIS)

1977-01-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 32

International Nuclear Information System (INIS)

1988-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 15

International Nuclear Information System (INIS)

1980-02-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 14

International Nuclear Information System (INIS)

1979-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 16

International Nuclear Information System (INIS)

1980-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 12

International Nuclear Information System (INIS)

1978-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 17

International Nuclear Information System (INIS)

1981-03-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 30

International Nuclear Information System (INIS)

1987-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 18

International Nuclear Information System (INIS)

1981-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 10

International Nuclear Information System (INIS)

1977-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 8

International Nuclear Information System (INIS)

1976-09-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 11

Energy Technology Data Exchange (ETDEWEB)

NONE

1978-02-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 31

Energy Technology Data Exchange (ETDEWEB)

NONE

1988-03-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 31

International Nuclear Information System (INIS)

1988-03-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 11

International Nuclear Information System (INIS)

1978-02-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 20

International Nuclear Information System (INIS)

1982-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 19

International Nuclear Information System (INIS)

1982-01-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 13

Energy Technology Data Exchange (ETDEWEB)

NONE

1979-02-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 30

Energy Technology Data Exchange (ETDEWEB)

NONE

1987-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 19

Energy Technology Data Exchange (ETDEWEB)

NONE

1982-01-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 23

Energy Technology Data Exchange (ETDEWEB)

NONE

1983-01-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 14

Energy Technology Data Exchange (ETDEWEB)

NONE

1979-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 23

International Nuclear Information System (INIS)

1983-01-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 13

International Nuclear Information System (INIS)

1979-02-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 22

International Nuclear Information System (INIS)

1983-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation Breeding for Crop Improvement

International Nuclear Information System (INIS)

Rajbir, S. Sangwan

2017-01-01

Chromosomes contain genes responsible of different traits of any organism. Induced mutation using chemical mutagens and radiation to modify molecular structure of plants played a major role in the development of high genetic variability and help develop new superior crop varieties. The Mutation Breeding is applicable to all plants and has generated lot of agronomically interesting mutants, both in vegetatively and seed propagated plants. The technique is easy but long and challenging to detect, isolate and characterize the mutant and gene. A specific dose of irradiation has to be used to obtain desired mutants. However, with modern molecular technique, the gene responsible for mutation can be identified. The CRISPR-Cas9 allows the removal of a specific gene which is responsible of unwanted trait and replacing it with a gene which induces a desired trait. There have been more than 2700 officially released mutant varieties from 170 different plant species in more than 60 countries throughout the world and A more participatory approach, involving all stakeholders in plant breeding, is needed to ensure that it is demand/farmers driven.

Molecular mutation breeding: Modern variety breeding for present and future needs

International Nuclear Information System (INIS)

Lagoda, P.J.L.; Mba, C.; Shu, Chikelu Mba; Shu, Q.Y.; Afza, R.; Till, B.; Spencer, M.; Lokko, Y.

2009-01-01

mutants enrich the crop germplasm useful for mitigating micronutrient deficiencies and meeting the requirements of niche industries. We also present the status of work on the use of a suite of integrated bio-/molecular technologies in enhancing the efficiency levels of induced crop mutagenesis. The paper highlights the central role of cellular biology in the rapid production of histonts as well as the innovative adaptation of the reverse genetics technology, Targeting Induced Local Lesions IN Genomes (TILLING) as a methodology for the high throughput detection of mutation events and hence significant reductions in the sizes of mutant populations for field trials. Reports on TILLING will include progress on the development of platforms for under-researched vegetative crops like banana and cassava. Perspectives for the future direction for the application of induced crop mutagenesis both as crop improvement and functional genomics tools are also provided. (author)

Nicotinamide starvation and inhibition of poly(ADP-Ribose) synthesis enhance the induced mutation in Chinese hamster V79 cells

International Nuclear Information System (INIS)

Okada, Gensaku; Kaneko, Ichiro; Mitsui, Hideki.

1987-01-01

The effects of nicotinamide (NA) deficiency and added NA and 3-aminobenzamide (3AB) on the cytotoxicity and the induction of mutations in Chinese hamster V79-14 cells were investigated. In NA deficiency the addition of NA (up to 4 mM) and 3AB (up to 7.5 mM) was not cytotoxic. The presence of NA prior to exposure to mitomycin C (MMC) or γ-rays produced a dose-dependent increase in the relative cloning ability of DNA-damaged cells. The lethality of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was significantly potentiated by pre-treatment with 5 mM 3AB, but no potentiation by 3AB was observed for MMC, ultraviolet (UV)-B light, or γ-rays. Among cells pre-cultured in NA-free medium there were increased frequencies of mutations at both the hypoxanthineguanine phosphoribosyltransferase (HGPRT) and the adenine phosphoribosyltransferase (APRT) loci following DNA damage. The enhancing effect by NA deficiency was time-dependent. Incubation with NA prior to DNA damage produced a significant reduction in the frequency of mutations. The addition of 3AB to the nicotinamide adenine dinucleotide (NAD + )-depleted cell cultures before or after the DNA damage also strongly increased the frequency of induced mutations, with increasing concentrations of 3AB up to 5 mM, but the frequency was reduced at higher concentrations. The interaction between NA deficiency and the addition of 3AB appears to act synergistically on mutation induction. A correlation was observed between the potential of inhibiting poly (ADP-ribose) polymerase and the enhancement of mutation frequency. (author)

Studies on induced mutations in garlic

International Nuclear Information System (INIS)

Selvaraj, N.; Natarajan, S.; Ramaraj, B.

2001-01-01

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

Molecular analysis of two mouse dilute locus deletion mutations: Spontaneous dilute lethal20J and radiation-induced dilute prenatal lethal Aa2 alleles

International Nuclear Information System (INIS)

Strobel, M.C.; Seperack, P.K.; Copeland, N.G.; Jenkins, N.A.

1990-01-01

The dilute (d) coat color locus of mouse chromosome 9 has been identified by more than 200 spontaneous and mutagen-induced recessive mutations. With the advent of molecular probes for this locus, the molecular lesion associated with different dilute alleles can be recognized and precisely defined. In this study, two dilute mutations, dilute-lethal20J (dl20J) and dilute prenatal lethal Aa2, have been examined. Using a dilute locus genomic probe in Southern blot analysis, we detected unique restriction fragments in dl20J and Aa2 DNA. Subsequent analysis of these fragments showed that they represented deletion breakpoint fusion fragments. DNA sequence analysis of each mutation-associated deletion breakpoint fusion fragment suggests that both genomic deletions were generated by nonhomologous recombination events. The spontaneous dl20J mutation is caused by an interstitial deletion that removes a single coding exon of the dilute gene. The correlation between this discrete deletion and the expression of all dilute-associated phenotypes in dl20J homozygotes defines the dl20J mutation as a functional null allele of the dilute gene. The radiation-induced Aa2 allele is a multilocus deletion that, by complementation analysis, affects both the dilute locus and the proximal prenatal lethal-3 (pl-3) functional unit. Molecular analysis of the Aa2 deletion breakpoint fusion fragment has provided access to a previously undefined gene proximal to d. Initial characterization of this new gene suggests that it may represent the genetically defined pl-3 functional unit

Clinical phenotype of 5 females with a CDKL5 mutation.

Science.gov (United States)

Stalpers, Xenia L; Spruijt, Liesbeth; Yntema, Helger G; Verrips, Aad

2012-01-01

Mutations in the X-linked cyclin dependent kinase like 5 (CDKL5) gene have been reported in approximately 80 patients since the first description in 2003. The clinical presentation partly corresponds with Rett syndrome, considering clinical features as intellectual disability, hypotonia, and poor visual, language, and motor development. However, these patients do not meet the consensus criteria for Rett syndrome since they lack the clear period of regression. Furthermore, in contrast to Rett syndrome, patients with CDKL5 mutations, have seizures or infantile spasms starting in the first weeks of life. We present clinical phenotype of 5 girls having a mutation in the CDKL5 gene. All mutations are novel and are pathogenic since they either lead to a frameshift in the reading frame or affect a consensus splice site. Four of the mutations are detected de novo in the affected girl.

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

International Nuclear Information System (INIS)

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

1993-01-01

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

Somatic mosaicism containing double mutations in PTCH1 revealed by generation of induced pluripotent stem cells from nevoid basal cell carcinoma syndrome.

Science.gov (United States)

Ikemoto, Yu; Takayama, Yoshinaga; Fujii, Katsunori; Masuda, Mokuri; Kato, Chise; Hatsuse, Hiromi; Fujitani, Kazuko; Nagao, Kazuaki; Kameyama, Kohzoh; Ikehara, Hajime; Toyoda, Masashi; Umezawa, Akihiro; Miyashita, Toshiyuki

2017-08-01

Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder characterised by developmental defects and tumorigenesis, such as medulloblastomas and basal cell carcinomas, caused by mutations of the patched-1 ( PTCH1 ) gene. In this article, we seek to demonstrate a mosaicism containing double mutations in PTCH1 in an individual with NBCCS. A de novo germline mutation of PTCH1 (c.272delG) was detected in a 31-year-old woman with NBCCS. Gene analysis of two out of four induced pluripotent stem cell (iPSC) clones established from the patient unexpectedly revealed an additional mutation, c.274delT. Deep sequencing confirmed a low-prevalence somatic mutation (5.5%-15.6% depending on the tissue) identical to the one found in iPSC clones. This is the first case of mosaicism unequivocally demonstrated in NBCCS. Furthermore, the mosaicism is unique in that the patient carries one normal and two mutant alleles. Because these mutations are located in close proximity, reversion error is likely to be involved in this event rather than a spontaneous mutation. In addition, this study indicates that gene analysis of iPSC clones can contribute to the detection of mosaicism containing a minor population carrying a second mutation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Mutation breeding newsletter. No. 28

International Nuclear Information System (INIS)

1986-09-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 24

Energy Technology Data Exchange (ETDEWEB)

NONE

1984-07-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 36

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-07-01

This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted.

Mutation breeding newsletter. No. 34

International Nuclear Information System (INIS)

1989-07-01

This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted

Mutation breeding newsletter. No. 34

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-07-01

This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted.

Mutation breeding newsletter. No. 25

International Nuclear Information System (INIS)

1985-01-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 28

Energy Technology Data Exchange (ETDEWEB)

NONE

1986-09-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 26

International Nuclear Information System (INIS)

1985-10-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 27

International Nuclear Information System (INIS)

1986-02-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 24

International Nuclear Information System (INIS)

1984-07-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 26

Energy Technology Data Exchange (ETDEWEB)

NONE

1985-10-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 25

Energy Technology Data Exchange (ETDEWEB)

NONE

1985-01-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 27

Energy Technology Data Exchange (ETDEWEB)

NONE

1986-02-01

This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 36

International Nuclear Information System (INIS)

1990-07-01

This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted

Establishment of induced pluripotent stem cell line (ZZUi010-A from an Alzheimer's disease patient carrying an APP gene mutation

Directory of Open Access Journals (Sweden)

Zhilei Wang

2017-12-01

Full Text Available Alzheimer's disease (AD is one of the most common neurodegenerative disorders. Previous studies have identified mutations in several genes, such as amyloid precursor protein (APP, presenilin-1 (PSEN1, and presenilin-2 (PSEN2, in patients with early-onset (<65 years familial AD. Recently, a patient with an APP gene mutation was identified; the dermal fibroblasts of the patient were obtained and a line of induced pluripotent stem cells (iPSCs was successfully generated using the Sendai-virus (SeV delivery system. The iPSC line will be useful for further study of the pathomechanism and drug screening for AD.

Rapid identification and recovery of ENU-induced mutations with next-generation sequencing and Paired-End Low-Error analysis.

Science.gov (United States)

Pan, Luyuan; Shah, Arish N; Phelps, Ian G; Doherty, Dan; Johnson, Eric A; Moens, Cecilia B

2015-02-14

Targeting Induced Local Lesions IN Genomes (TILLING) is a reverse genetics approach to directly identify point mutations in specific genes of interest in genomic DNA from a large chemically mutagenized population. Classical TILLING processes, based on enzymatic detection of mutations in heteroduplex PCR amplicons, are slow and labor intensive. Here we describe a new TILLING strategy in zebrafish using direct next generation sequencing (NGS) of 250 bp amplicons followed by Paired-End Low-Error (PELE) sequence analysis. By pooling a genomic DNA library made from over 9,000 N-ethyl-N-nitrosourea (ENU) mutagenized F1 fish into 32 equal pools of 288 fish, each with a unique Illumina barcode, we reduce the complexity of the template to a level at which we can detect mutations that occur in a single heterozygous fish in the entire library. MiSeq sequencing generates 250 base-pair overlapping paired-end reads, and PELE analysis aligns the overlapping sequences to each other and filters out any imperfect matches, thereby eliminating variants introduced during the sequencing process. We find that this filtering step reduces the number of false positive calls 50-fold without loss of true variant calls. After PELE we were able to validate 61.5% of the mutant calls that occurred at a frequency between 1 mutant call:100 wildtype calls and 1 mutant call:1000 wildtype calls in a pool of 288 fish. We then use high-resolution melt analysis to identify the single heterozygous mutation carrier in the 288-fish pool in which the mutation was identified. Using this NGS-TILLING protocol we validated 28 nonsense or splice site mutations in 20 genes, at a two-fold higher efficiency than using traditional Cel1 screening. We conclude that this approach significantly increases screening efficiency and accuracy at reduced cost and can be applied in a wide range of organisms.

The frequency pattern of dumpy mutations induced by x-rays in the successive stages of oocytes of Drosophila

International Nuclear Information System (INIS)

Miyamoto, Tomio; Nakao, Yoshio

1978-01-01

The frequency patterns of the different kinds of dumpy mutations induced by x-rays (1,500 and 3,000R) in the successive stages of oocyte development were investigated by transferring the inseminated females daily to fresh vials for 12 days. Under this transferring procedure, the first egg-laying period represents oocytes irradiated when they are at stage 14, and the subsequent ones represent progressively earlier stages of oocyte development at the time of irradiation. The results obtained indicate that (1) the overall yield of complete dumpy mutations recovered in the first six day egg-laying periods (1st-6th day) are relatively higher than that in the subsequent six day periods (7th-12th day), showing a response pattern with a higher mutation frequency in the early egg-laying periods and a lower frequency in the late egg-laying periods; (2) the frequency patterns for the exceptions of the ol and lv types and those of ov and olv types through the sampling periods are practically similar to those observed in the total dumpy mutations; (3) a somewhat peculiar frequency pattern, which seems to be variable by dose, is found in the yield of the o and v exceptions. At the exposure level of 1,500R, no definite difference in response pattern for these exceptions is found, though a response pattern which is practically similar to that observed in the total dumpy mutations is found at the exposure level of 3,000R. The foregoing findings seem to indicate that the different kinds of dumpy exceptions are affected at various degrees by the difference in the cell stages of oocyte. This may possibly suggest that these exceptions are different from each other in the nature of their mutations, that is to say, whether they are associated with chromosome breakage events or not. (auth.)

Induction of mutations in the blue-green alga Plectonema boryanum Gomont

International Nuclear Information System (INIS)

Singh, R.N.; Kashyap, A.K.

1977-01-01

Mutations to cyanophage and streptomycin resistance were induced in the filamentous blue-gree alga Plectonema boryanum IU 594 after treatment with ultraviolet irradiation, N-methyl-N'-nitro-Nnitrosoguanidine, acriflavine, 2-aminopurine and caffeine. Phage-resistant mutants were obtained with all the mutagens tested. Their efficiencies were in the order: MNNG>UV>acriflavine >2-AP>caffeine. In contrast, the drug-resistant mutants were not induced by base analogues: the efficiencies were: acriflavine>MNNG>UV. Lethal and mutational lesions induced with UV were efficiently repaired under photo-reactivating conditions whereas post-treatment with caffeine resulted in enhanced mutation frequencies especially at low UV doses. Neither survival nor mutagenesis was enhanced by keeping the MNNG-treated population in subdued light

Mutation breeding newsletter. No. 4

Energy Technology Data Exchange (ETDEWEB)

NONE

1974-08-01

This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 6

Energy Technology Data Exchange (ETDEWEB)

NONE

1975-08-01

This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 5

Energy Technology Data Exchange (ETDEWEB)

NONE

1975-02-01

This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 3

International Nuclear Information System (INIS)

1974-01-01

This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 3

Energy Technology Data Exchange (ETDEWEB)

NONE

1974-01-01

This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 29

Energy Technology Data Exchange (ETDEWEB)

NONE

1987-02-01

This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 4

International Nuclear Information System (INIS)

1974-08-01

This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

Mutation breeding newsletter. No. 7

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-01-01

This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 44

International Nuclear Information System (INIS)

1999-04-01

This issue of the Newsletter presents research reports on the role of radiation induced mutation and chemical mutagens in improving productivity, disease resistance; cold and salinity tolerance of various crops and ornamental plants

Mutation breeding newsletter. No. 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1972-05-01

This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.