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Ichikawa S, Wushur S. Further yearly analyses of spontaneous pink mutant events in the stamen hairs of tradescantia clone BNL 4430 cultivated in the NSC growth chamber. Genes Genet Syst 2001; 76:199-207. [PMID: 11569503 DOI: 10.1266/ggs.76.199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In order to confirm the results obtained in the previous 1-year-term (December 12, 1998, through December 10, 1999) scorings and analyses of spontaneous pink mutant events (PMEs) in the stamen hairs of Tradescantia clone BNL 4430 cultivated in a nutrient solution circulating (NSC) growth chamber, similar scorings and analyses were continued for another 52-week period from December 11, 1999, through December 8, 2000. The environmental conditions were not changed, except for a minor modification in the method of supplying the nutrient solution used. During the scoring period, 732,128 stamen hairs with an average cell number of 24.90 cells were observed, and 2,368 PMEs were detected. The overall spontaneous somatic mutation frequency was 1.35 +/- 0.03 PMEs per 10(4) hair-cell divisions, which was significantly lower than the value of 1.56 +/- 0.03 determined in the previous 52-week period, and the frequencies were lower during April through September than in other months, the period showing lower frequencies lasting 1-month longer than in the previous year. The present results reconfirmed the occurrence of a clear seasonal variation in the spontaneous mutation frequency in the NSC growth chamber, and the lower overall frequency, probably related to the minor modification in supplying the nutrient solution, is helpful for conducting mutagenicity tests at low levels, offering a lower background level. The analyses of the sectoring patterns of all these PMEs showed that the most of the 203 cases of multiple (two to five) pink sectors observed in the same stamen hairs (scored as 253 PMEs for calculating mutation frequency) were the results of events involving somatic recombinations occurred in single cells or cell lineages, rather than those of two or more independent somatic mutations occurred in different cells, agreeing with our previous study, and the significance of somatic recombinations in causing single PMEs was also reconfirmed.
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Affiliation(s)
- S Ichikawa
- Department of Regulation Biology, Faculty of Science, Saitama University, Saitama City, Japan
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Ichikawa S, Wushur S. Analyses of spontaneous pink mutant events in the stamen hairs of Tradescantia clone BNL 4430 cultivated in a nutrient solution circulating growth chamber. Mutat Res 2000; 472:37-49. [PMID: 11113696 DOI: 10.1016/s1383-5718(00)00102-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In order to obtain more fundamental data on Tradescantia clone BNL 4430, one of the most suitable testers for environmental mutagens, the occurrences of spontaneous somatic pink mutations in the stamen hairs were scored for 52 weeks from 12 December 1998 to 10 December 1999, cultivating the young inflorescence-bearing shoots with roots in a nutrient solution circulating (NSC) growth chamber. The environmental conditions in the chamber were 22.0+/-0.5 degrees C during the 16h day with the light intensity of 7.5klx from white fluorescent tubes, and 20.0+/-0.5 degrees C at night. During the scoring period, 697,443 stamen hairs with an average cell number of 25.36 were observed and 2642 pink mutant events (PMEs) were detected. The overall spontaneous mutation frequency was 1.56+/-0.03 PMEs per 10(4) hair-cell divisions, and the frequency was significantly lower in May, July and August and significantly higher in November and December. By analyzing the sectoring patterns of 1856 PMEs (70.25% of PMEs detected), the most of 172 cases of multiple (two to five) pink sectors observed in the same hairs (scored as 232 PMEs for calculating mutation frequency) were found to be the results of events involving somatic recombinations occurred in single cells or cell lineages, rather than those of two or more independent somatic mutations occurred in different cells. This finding clearly shows the significance of somatic recombinations in producing such multiple sectors (382 sectors in total) which occupied 19.0% of the 2006 pink sectors in total analyzed. Somatic recombinations were considered to be playing a significant role also in producing single PMEs in the stamen hairs.
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Affiliation(s)
- S Ichikawa
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University, 338-8570, Urawa, Japan
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Ichikawa S, Shima N, Ishii C, Kanai H, Sanda-Kamigawara M, Matsuura-Endo C. Variation of spontaneous somatic mutation frequency in the stamen hairs of Tradescantia clone BNL 02. Genes Genet Syst 1996. [DOI: 10.1266/ggs.71.159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Sadao Ichikawa
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Naoko Shima
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Chizu Ishii
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Hiromi Kanai
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Marie Sanda-Kamigawara
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Chie Matsuura-Endo
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
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SANDA-KAMIGAWARA M, TOMIYAMA M, ICHIKAWA S. Sectoring patterns of spontaneous and induced somatic pink mutations in the stamen hairs and petals of mutable and stable clones of Tradescantia. Genes Genet Syst 1995. [DOI: 10.1266/ggs.70.339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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ICHIKAWA S, SHIMA N, XIAO LZ, MATSUURA-ENDO C, HARADA H, YOGO A, OKUMURA M. Flower production, stamen-hair growth, and spontaneous and induced somatic mutation frequencies in Tradescantia cuttings and shoots with roots cultivated with nutrient solutions. Genes Genet Syst 1995. [DOI: 10.1266/ggs.70.585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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ICHIKAWA S, SHIMA N, XIAO LZ, MATSUURA-ENDO C, HARADA H, YOGO A, OKUMURA M. Flower production, stamen-hair growth, and spontaneous and induced somatic mutation frequencies in Tradescantia cuttings and shoots with roots cultivated with nutrient solutions. ACTA ACUST UNITED AC 1995. [DOI: 10.1266/jjg.70.585] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Sadao ICHIKAWA
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Naoko SHIMA
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Ling Zhi XIAO
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Chie MATSUURA-ENDO
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Hiroshi HARADA
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Akiko YOGO
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Mikiko OKUMURA
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
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ICHIKAWA S. Sectoring patterns of spontaneous and radiation-induced somatic pink mutations in the stamen hairs of a temperature-sensitive mutable clone of Tradescantia. Genes Genet Syst 1994. [DOI: 10.1266/ggs.69.577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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SANDA-KAMIGAWARA M, ICHIKAWA S. Identity of normal and mutant flower-color pigments in four different Tradescantia clones confirmed by means of microspectrophotometry. ACTA ACUST UNITED AC 1993. [DOI: 10.1266/jjg.68.137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Marie SANDA-KAMIGAWARA
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Sadao ICHIKAWA
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
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SANDA-KAMIGAWARA M, ICHIKAWA S. Identity of normal and mutant flower-color pigments in four different Tradescantia clones confirmed by means of microspectrophotometry. Genes Genet Syst 1993. [DOI: 10.1266/ggs.68.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Ichikawa S. Tradescantia stamen-hair system as an excellent botanical tester of mutagenicity: its responses to ionizing radiations and chemical mutagens, and some synergistic effects found. Mutat Res 1992; 270:3-22. [PMID: 1383719 DOI: 10.1016/0027-5107(92)90096-k] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The stamen-hair system of Tradescantia heterozygous for flower color (blue/pink, the pink color being recessive) is an excellent botanical tester of mutagenicity. It is especially useful for detection of the genetic effects of both ionizing radiations and chemical mutagens at the low levels of exposure to which the human population may actually be exposed. This system exhibits a high accuracy in laboratory experiments, and is also applicable for in situ monitoring in the environment. The use of the Tradescantia stamen-hair system is inexpensive and requires only a short training time. Simplified scoring methods which endorse a high statistical accuracy have newly been developed to score larger samples of pink somatic mutations. In the present paper, the most widely used clones, methods for their cultivation, and use in a variety of experiments with radiations and chemical mutagens are also reviewed.
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Affiliation(s)
- S Ichikawa
- Department of Regulation Biology, Faculty of Science, Saitama University, Urawa, Japan
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Ichikawa S, Ishii C. Somatic mutation frequencies in the stamen hairs of Tradescantia grown in soil samples from the Bikini Island. IDENGAKU ZASSHI 1991; 66:27-40. [PMID: 2064800 DOI: 10.1266/jjg.66.27] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Somatic pink mutation frequencies in the stamen hairs of Tradescantia BNL 02 clone grown for 76 days in two soil samples taken from the Bikini Island (where a hydrogen bomb explosion test had been conducted in 1954) were investigated. A significantly high mutation frequency (2.58 +/- 0.17 pink mutant events per 10(3) hairs or 1.34 +/- 0.09 pink mutant events per 10(4) hair-cell divisions) was observed for the plant grown in one of the two Bikini soil samples, as compared to the control plants (1.70 +/- 0.14 or 0.88 +/- 0.07, respectively) grown in the field soil of Saitama University. The soil sample which caused the significant increase in mutation frequency contained 6,880 +/- 330 mBq/g 137Cs, 62.5 +/- 4.4 mBq/g 60Co, and some other nuclides; a 150 microR/hr exposure rate being measured on the surface of the soil sample. The effective cumulative external exposures measured for the inflorescences of the plant grown in this soil sample averaged at most 60.8 mR, being too small to explain the significant elevation in mutation frequency observed. On the other hand, internal exposure due to uptake of radioactive nuclides was estimated to be 125 mrad (1.25 mGy) as an accumulated effective dose, mainly based on a gamma-spectrometrical analysis. However, it seemed highly likely that this value of internal exposure was a considerable underestimate, and the internal exposure was considered to be more significant than the external exposure.
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Affiliation(s)
- S Ichikawa
- Department of Regulation Biology, Faculty of Science, Saitama University, Urawa
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ICHIKAWA S, IMAI T, NAKANO A. Comparison of somatic mutation frequencies in the stamen hairs of one mutable and two stable clones of Tradescantia treated with small doses of gamma rays. ACTA ACUST UNITED AC 1991. [DOI: 10.1266/jjg.66.513] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Sadao ICHIKAWA
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Toshihiko IMAI
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
| | - Atsushi NAKANO
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University
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Vig BK. Somatic mosaicism in plants with special reference to somatic crossing over. ENVIRONMENTAL HEALTH PERSPECTIVES 1978; 27:27-36. [PMID: 367771 PMCID: PMC1637313 DOI: 10.1289/ehp.782727] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Plant systems in use for the detection of environmental mutagens appear capable of detecting all types of genetic effects which can be studied in animals. The study of somatic mosaicism, however, is better developed in plants than in higher animals. A case is presented here which shows the ability of plant systems in analyzing a host of genetic end points, including chromosome aberrations like deletions, somatic crossing over, numerical inequality, gene conversion, paramutations and point mutations. The systems in general use utilize certain varieties of Tradescantia, Glycine max, Nicotiana tabacum, Antirrhinum majus, Petunia hybrida, and Arabidopsis thaliana. Heterozygous plants or their homozygous counterparts with gene markers affecting chlorophyll development or anthocyanin in floral parts are exploited in these studies. Mutagens produce different frequencies of different types of spots typical of the mode of action of the agent. Analysis of these parameters may be used to predict, at least qualitatively, the kind of genetic damage that might be produced in man. Besides, one can test the validity of interpretation by traditional progeny tests of plants raised from tissue culture from sectors as in Nicotiana and/or by precursor analysis as done in Antirrhinum. The study of mosaicism in plants offers quite inexpensive, rapid, and reliable tests of mutagenicity at least as a preliminary eukaryotic test system.
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