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Volume 56, Issue 1
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Hirohisa TSUDA1981 Volume 56 Issue 1 Pages 1-8
Published: 1981
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSChromosomal aberrations were observed in cultured mammalian cells (CHO-K1 Chinese hamster cells, V79 Chinese hamster cells, Syrian hamster cells, and BALB/c mouse cells) after treatment with hydrogen peroxide (H2O2; 0.1-0.5mM or 0.01-0.1mM) for 3h. The cytotoxic and clastogenic effects of H2O2 were clearly reduced by the addition of catalase. In contrast to the clastogenic potential, H2O2 did not enhance the frequency of mutation in V79 cells, whether the marker for mutation was 8-azaguanine resistance or ouabain resistance.View full abstractDownload PDF (698K) -
Hirohisa TSUDA1981 Volume 56 Issue 1 Pages 9-18
Published: 1981
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSEffects of a tumor promotor, 12-O-tetradecanoylphorbol-13-acetate (TPA), on mutagenesis (resistance to 8-azaguanine and to ouabain) in Chinese hamster V79-H3 cells were examined. TPA, at concentrations ranging from 10-6 μg/ml to 5μg/ml, enhanced the frequency of 8-azaguanine-resistant mutation induced by N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). Whether TPA was present during the mutation expression time (0-72h after MNNG treatment) or during the mutation selection time (72-240h after MNNG treatment), this enhancing effect was observed. The enhancing effect of TPA reached a plateau at a concentration of 10-5μg/ml. It was suspected that the effect of TPA might be due to its inhibitory action on metabolic cooperation. However, this possibility was almost eliminated by measuring the amount of actual metabolic cooperation. At present, it is difficult to explain at the molecular level why TPA enhances the frequency of 8-azaguanine-resistant mutation induced by MNNG. The results, however, are consistent with the "two stage" theory of carcinogenesis. TPA did not affect the frequency of ouabain-resistant mutation induced by MNNG.View full abstractDownload PDF (407K) -
Studies on the genetical and biochemical properties of the Kiuki mutant of the silkworm, Bombyx moriToshio MAZDA, Motoo TSUSUÉ, Sakae SAKATE, Hiroshi DOIRA1981 Volume 56 Issue 1 Pages 19-26
Published: 1981
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSGenetic studies of the Bombyx mori Kiuki mutant were made on the segregation of the F2 and BF1 phenotypes. Assay of sepialumazine in these phenotypes revealed that the Kiuki mutant is an incomplete dominant. A symbol Sel is given to the mutant gene. Enzymatic studies on F2 progeny showed that the yellow larval integument colour characteristic of the mutant, which is due to accumulation of sepialumazine, is dependent on the activity of sepiapterin deaminase. Linkage test showed that the Sel is independent of the so far established 23 linkage groups but represents one of the still unknown group among remaining five chromosomes.View full abstractDownload PDF (364K) -
Mitsuru MINEZAWA, Kazuo MORIWAK, Kyoji KONDO1981 Volume 56 Issue 1 Pages 27-39
Published: 1981
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSElectrophoretic survey of ten genetic loci, Es-1, Es-2, Es-5, Es-6, Amy-1, Amy-2, Prt-1, Prt-2, Mod-1 and Trf was carried out in wild populations of Japanese house mouse. All loci except Trf were polymorphic and two distribution patterns were observed in several alleles. E3-2a, E3-2b, Amy-1a and Prt-1a were distributed more frequently in the peripheral regions as well as Hbbd allele, and Es-5b was found in the southern regions as well as Id-1a and Id-1c previously reported. Calculation of genetic distance on 12 loci demonstrates three regional groups, Hokkaido, Mainland and Southern regions. This feature is consistent with the multiple migration hypothesis.
Rough estimation of the genetic distance and comparison of the allelic composition between Japanese and Western Hemisphere populations suggests close relationship of the Japanese mouse to M. m. musculus and remote relationship to three other Mus populations, M. m. domesticus, M. m, brevirostris and Mus spretus. Evidently, the Japanese mouse seems to belong to a unique Mus musculus subspecies, M. m, molossinus.View full abstractDownload PDF (529K) -
II. Identification of extra chromosomes in trisomic plants and banding structure on some chromosomesNori KURATA, Nobuo IWATA, Takeshi OMURA1981 Volume 56 Issue 1 Pages 41-50
Published: 1981
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSTwelve strains of primary trisomics were examined by the karyotype analysis. Four strains, B, C, E and H types were decided to have individual extra chromosomes K6, K12, K4 and K10 respectively. Between K5 and K9 and among K7, K8 and K11 chromosomes, there were some difficulties to discriminate each other. In well conditioned nuclei, however, K5, K7, K9 and K11 extra chromosomes were found to be carried by the A, D, L and F type trisomics respectively. Extra chromosome K8 was present in G, I, J and K type trisomics. Three kinds of extra chromosomes (K1, K2, K3) were not found in these 12 strains. Through the present study the modified technique for stretching the chromosomes appeared to be also promising to characterize chromosome bands.View full abstractDownload PDF (2019K) -
Kaname MOGAMI, Yoshiaki NONOMURA, Yoshiki HOTTA1981 Volume 56 Issue 1 Pages 51-65
Published: 1981
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSElectron microscopy revealed that, although both thick and thin filaments are present, Z-band and myofibrillar organization are totally lost in indirect flight muscle (IFM) of a Drosophila muscle mutant wings-up B (wup B). The Z-band deficiency correlates well with the gene dosage; in wup B/wup B+ heterozygotes, normal internal structure of the Z-band is restricted only within the central core of the myofibrils. Two-dimensional gel electrophoresis (O'Farrell 1975) revealed that nine myofibrillar proteins are either absent or reduced in the indirect flight muscle of the mutant. Some of the anomalies are not restored in heterozygotes. These observations suggest a possibility that the product of wup B+ gene is one of the Z-band components, without which the regular arrangement of thick and thin filaments cannot be maintained. Possible mechanisms for the fact that a single mutation causes multiple changes on the gel are discussed. We concluded that absence of one component causes disappearance or reduction of others which are functionally and/or structurally related.View full abstractDownload PDF (1972K) -
Taira KATAYAMA, Wataru ONIZUKA, Young-Boum SHIN1981 Volume 56 Issue 1 Pages 67-71
Published: 1981
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSCytological and morphological studies were made on the F1 plants (OF1141 and OF1139) obtained from the crosses Oryza minuta Presl. (Y22, 2n=48, BBCC)×O. ridleyi Hook. (W0001, 2n=48) and O. officinalis Wall. (W1281, 2n=24, CC)×O. ridleyi. Morphological characteristics of both the F1 plants resembled their female parents, O. minuta and O. officinalis, more closely than O. ridleyi. Moreover, the F1 plants were especially characterized by producing runners. In somatic cells of the F1 plants, 2n=48 chromosomes for the former and 2n=36 for the latter were counted. At meiotic division of the former cross-combination, most chromosomes failed to make pairing. These results suggest that the genome constitutions of O. ridleyi differed from the genomes of O. minuta, B and C.View full abstractDownload PDF (529K) -
III. Variation of glucosephosphate isomerase (GPI) in a natural population of P, iloktsuenensisTakeshi AGATSUMA1981 Volume 56 Issue 1 Pages 73-77
Published: 1981
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSElectrophoretic studies were carried out on glucosephosphate isomerase (GPI) in a parasitic helminth, Paragonimus iloktsuenensis, using starch gel electrophoresis. It was found that GPI isozymes are highly polymorphic in a natural population. From the observed distribution of phenotypes of banding patterns, it was considered that GPI isozymes have a dimeric structure and are controlled by a single locus with three codominant alleles.View full abstractDownload PDF (404K)
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