巻号一覧
54 巻, 2 号
選択された号の論文の7件中1～7を表示しています
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TADASHI IMAIZUMI1979 年 54 巻 2 号 p. 55-67
発行日: 1979年
公開日: 2007/05/21
ジャーナル フリーTwo different wild strains, Oregon-RS and Tokyo, have been maintained under constant darkness for about 24 years by Mori and his collaborators. Of these two strains, a morphological alteration, the striking elongation of head bristles, was detected in flies of Oregon-RS, whereas such remarkable alteration was not found in flies of Tokyo. Some discussions were carried out about the nature of alteration of bristles under darkness.抄録全体を表示PDF形式でダウンロード (2083K) -
YUTAKA INOUE, TAKAO K. WATANABE1979 年 54 巻 2 号 p. 69-82
発行日: 1979年
公開日: 2007/05/21
ジャーナル フリーFour common cosmopolitan inversions (2Lt, 2RNS, 3LP, 3RP), four rare cosmopolitan inversions (2LA, 3LM, 3RC, 3RMo) and two recurrent endemic inversions (2LW, 3LY) were found to be distributed in Japanese natural populations of Drosophila melanogaster. Moreover, seventeen unique endemic inversions were rather randomly detected in many natural populations as well as in stocks that originated from small number of wild caught flies. The frequency of inversions was generally higher in Southern populations than in Northern populations, especially in the case of In(3R)P. The polymorphic inversions did not show any heterosis in the present analysis. The frequencies of inversion heterozygotes were almost equal to the expectaions with a few exceptions of a scarcity of the heterozygotes over the expectation. In the Katsunuma population, some inversions decreased remarkably within ten years, which resulted in the change of abundance order among four common cosmopolitan inversions. This kind of change might have occurred in the Shiojiri population. Both populations are very interesting in that new inversions are increasing in frequency and replacing the old ones.抄録全体を表示PDF形式でダウンロード (1251K) -
YUTAKA INOUE1979 年 54 巻 2 号 p. 83-96
発行日: 1979年
公開日: 2007/05/21
ジャーナル フリーThree Japanese natural populations of Drosophila melanogaster were transferred to laboratory cages and kept at three temperature conditions (25°C constant, 20-30°C fluctuating and 18°C constant). Their chromosomal variation was examined after about 20 months. Polymorphic inversions found at high frequency in nature were almost eliminated from the cage populations at 25°C and 20-30°C condition, and were in the process of being eliminated at 18°C. The elimination of the polymorphic inversions was also confirmed in the periodical monitor of cage populations. Inversions were disadvantageous compared to the standard chromosomes in laboratory cages, and the selection coefficient of the average inversion was found to be 0.05 or 0.06 for the heterozygotes and 0.10 or 0.12 for the homozygotes. The direct estimates of fitness components showed that the inversion chromosomes had various selective values in productivity but they had relatively constant selective values in viability which might result in the elimination of inversions. The frequency of unique (newly occurring) inversions in cage populations was equal to that found in nature, 0.0026 per major autosome arm per generation.抄録全体を表示PDF形式でダウンロード (1287K) -
MASAMITSU YAMAGUCHI, MEI-YIN CHOU, HIROYUKI MATSUMOTO, HIROSUKE FUKASA ...1979 年 54 巻 2 号 p. 97-108
発行日: 1979年
公開日: 2007/05/21
ジャーナル フリーTwo distinct DNA polymerases, designated A and B, have been partially purified from rapidly growing apical tissues of the cauliflower inflorescence (Brassica oleracea, var. botrytis). They were readily separable from each other, because enzyme A was adsorbable on an anion-exchanger, but enzyme B was not. The effects of divalent rations and ionic strength on both enzyme activities were very different. Enzyme A utilized activated DNA well at low concentration of MgCl2 or at low ionic strength, but heat-denatured DNA was utilized more effectively than was activated DNA at high concentration of MgCl2. Enzyme B also utilized much more heat-denatured DNA and poly (rA)•(dT)10 at high ionic strength. Gel chromatography with Sephadex G-200 revealed that enzyme A has a higher molecular weight (approx. 100, 000) than enzyme B (approx. 75, 000). It has been also described that some points of properties in enzyme A and B resemble to those of the two DNA polymerase -α and -β from mammalian cells, respectively. The existence of the third enzyme, designated C, in the fraction with enzyme A was suggested with an assay system using poly (rA)•(dT)10 as the template.抄録全体を表示PDF形式でダウンロード (1129K) -
FUMIO SUZUKI, HIROYOSHI HOSHI, MASAKATSU HORIKAWA1979 年 54 巻 2 号 p. 109-119
発行日: 1979年
公開日: 2007/05/21
ジャーナル フリーThe ability of Chinese hamster hai cells to repair damage related to cell death and mutational change induced by X-rays was studied by using a sensitive forward mutation system from prototrophic CH-hai Cl 23 cells to auxotrophs. The results obtained from the dose rate and split-dose experiments suggest that Chinese hamster hai cells have repair mechanisms for the sublethal and mutational damage induced by X-rays and that these mechanisms act in common for repair of both types of damage. In addition, we also found that these cells have repair abilities for lethal and mutational damage induced by a potentially lethal dose of radiation.抄録全体を表示PDF形式でダウンロード (1039K) -
1. GENIC ANALYSIS FOR THE F1 STERILITY BETWEEN O. SATIVA L. AND O. GLABERRIMA STEUDYOSHIO SANO, YAW-EN CHU, HIKO-ICHI OKA1979 年 54 巻 2 号 p. 121-132
発行日: 1979年
公開日: 2007/05/21
ジャーナル フリーThe F1 plants between Oryza sativa L. and O. glaberrima Steud. are highly pollen-sterile although the chromosomes normally pair in meiosis. They can be backcrossed as some embryosacs remain functional. Isogenic F1-sterile lines having the genetic background of sativa and glaberrima parents were isolated from B8F2 plants, respectively. They were self-fertile and showed semi-sterility in the F1 plants when crossed with the parental strains. But the F2 plants were fully fertile. This F1 sterility was most favorably explained by a “one locus sporo-gametophytic interaction” model of sterility genes which assumes that the sativa and glaberrima parents have S1aS1a S2S2 and S1S1 S2aS2a, respectively, and that if a S gene is present in the maternal tissue, gametes with Sa deteriorate. Then, the F1 plants having S/Sa are 50 percent sterile and produce S gametes only. Evidence for this hypothesis was that in an S1/S1a hybrid, a gene controlling apiculus coloration was closely linked with S1; then, the F2 produced colored plants only since the gametes carrying S1a and the colorless allele were eliminated.
The presence of other genic systems was also suggested. For instance, a true-breeding partly sterile line with sativa background was obtained, which seemed to be homozygous for some complementary or duplicate recessive genes causing sporophytic sterility. Possibly, the F1 sterility is controlled by a complex of genic systems, and the backcrossing to derive isogenic F1-sterile lines in this work resulted in extraction of one of them.抄録全体を表示PDF形式でダウンロード (1140K) -
MAKOTO IKEBUCHI, YOSHIO NAKAO1979 年 54 巻 2 号 p. 133-137
発行日: 1979年
公開日: 2007/05/21
ジャーナル フリーWhen Drosophila sperm treated with different doses of ethyl methanesulfonate (EMS) were stored in untreated females, changes in the yields of translocations and dominant lethals were examined. At high EMS doses yielding 25-33% X-linked recessive lethals, the frequencies of both translocations and dominant lethals increased markedly with increasing storage time. At low doses yielding 7-15% recessive lethals, however, no increase in their yields was detected after the storage of treated sperm, indicating that storage effects of EMS are dose dependent.抄録全体を表示PDF形式でダウンロード (464K)
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