巻号一覧
58 巻, 4 号
選択された号の論文の12件中1～12を表示しています
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Hwa DAI, Haruko ICHIKAWA-RYO, Sohei KONDO1983 年 58 巻 4 号 p. 283-295
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーTo study the dose-rate dependence of mutagenesis in Escherichia coli by ultraviolet radiation (UV) and UV-mimetic chemical, 4-nitroquinoline 1-oxide (4NQO), equal total doses of UV or 4NQO were given to bacteria at high dose- rates in single doses and at low dose-rates by continuous exposure or in fractionated doses during a 7 hr period of holding the cells in buffer. Yields of mutations to prototrophy in a repair-proficient strain greatly decreased after low dose-rate treatment with either UV or 4NQO when compared to those under high dose-rate treatment. On the other hand, a uvrA- derivative of the repair-proficient which lacks excision rapair ability, showed no reduction in UV- or 4NQO-induced mutation frequencies by lowering the dose-rate. These results support the assumption that excision repair works at higher efficiency for UV- or 4NQO-induced damage in DNA under low dose-rate treatment than under high dose-rate treatment. Mutagenicity of 4NQO was reduced about 20 times in the repair-proficient strain by lowering the dose-rate. The mutation-frequency-versus-dose curve showed, however, no indication of a threshold dose below which bacteria with proficient DNA repair become resistant to mutagenesis.抄録全体を表示PDF形式でダウンロード (569K) -
Terumi MUKAI, Shin-ichi KUSAKABE, Hidenori TACHIDA1983 年 58 巻 4 号 p. 297-314
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーUsing the estimates of additive genetic variance and dominance variance as well as the regression coefficient of heterozygotes on the sums of the component homozygotes (βY•X) and the inverse of the regression coefficient of the sum of the two homozygotes on their heterozygotes (1/βX•Y) with respect to viability estimated by the Cy method, it was tested whether or not frequency- dependent selection is a general rule with respect to viability polygenes. Two types of frequency-dependent selection models were considered: (1) gene frequency-dependent model and (2) zygotic frequency-dependent model. The βY•X and 1/βY•X values predicted on the basis of the frequency-dependent selection models and the ratio of the dominance variance to the additive variance are inconsistent with the actual estimates of these parameters for the Florida, Ishigaki-jima (Japan), Raleigh (N.C.) and Aomori (Japan) populations. The same conclusion was obtained for newly arisen polygenic viability mutations. Thus, it is speculated that frequency-dependent selection is not a general rule for viability polygenes as well as polymorphic isozyme genes.抄録全体を表示PDF形式でダウンロード (667K) -
Ken-Ichi WAKAHAMA, Tamiko SHINOHARA, Machiko HATSUMI, Satoko UCHIDA, O ...1983 年 58 巻 4 号 p. 315-326
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーMetaphase chromosome configurations of 23 species and subspecies belonging to five subgroups of the immigrans species group of Drosophila were examined by the Giemsa staining method, from the point of view of the phylogenetic relationships in this species group.
New to science are the descriptions of the karyotypes of five species, Taxon-C, Taxon-F, D. niveifrons, D. quadrilineata and D. neohypocausta which are 2n=8, 2R+1V+1D; 2n=8, 2R+1V+1D; 2n=8, 2R+1V+1D; 2n=12, 4R+1V+1D; and 2n=6, 2R+1V, respectively.
The karyotypes of the other species were also examined and compared with earlier descriptions. Some of our observations agreed with earlier ones but the remainder showed some major or minor differences from the previous reports.
The basic karyotype of the species belonging to the immigrans species group was 2n=8, 2R+1V+1D (or short rod). The karyotypes of D. annulipes and D. quadrilineata of the D. quadrilineata subgroup, of D. argentostriata and D. silvistriata of the D. lineosa subgroup and of D. neohypocausta of the D. hypocausta subgroup differed fundamentally from the basic type of the immigrans species group. These five species might be somewhat remote from the other species of the immigrans group.
Some species exhibited intraspecific variations among the forms of the Y chromosome and Chromosome 4, with additional heterochromatin.
In the D. nasuta subgroup, it seemed that fusions were important factors in their evolution. D. albomicans is the most advanced species, and from considerations of morphological similarities, results of hybridization tests, karyotypes, and geographical distribution, D. nasuta is the most plausible species from which D. albomicans originated.
D. albomicans collected from the Chiangmai population in Thailand had supernumerary chromosomes, the most peculiar phenomenon among the karyotype variations of the immigrans species group. These chromosomes may be maintained consistently in this population.抄録全体を表示PDF形式でダウンロード (567K) -
Tsuneyuki OIKAWA, Michihiro C. YOSHIDA, Hitoshi SATOH, Kenji YAMASHINA ...1983 年 58 巻 4 号 p. 327-336
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーSomatic cell hybrids between an AKR mouse thymic lymphoma cell line and normal F344 rat spleen cells were isolated in order to assign the rat major histocompatibility complex (MHC) (RT1) to a specific chromosome. Six primary hybrid clones and 3 of their derivatives were examined for expression of the RT1 antigens on the cell surface by the complement-dependent cytotoxicity test and simultaneously for their karyotypes by the Hoechst 33258/quinacrine mustard double staining method. All of these hybrid clones consisted of 2 sets of mouse and 1 set of rat parental cells, with a preferential loss of rat chromosomes. A high degree of concordance was shown between the expression of the RT1 antigen and the presence or absence of rat chromosome 14 in the original 6 hybrid clones. This was confirmed in 1 spontaneous and 2 immunoselected RT1-negative segregants from RT1-positive clones. These results led us to propose that the rat MHC is located on chromosome 14.抄録全体を表示PDF形式でダウンロード (450K) -
Motoe KATOH, Noriho TANAKA, Shigeo IWAHARA1983 年 58 巻 4 号 p. 337-344
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーCytogenetic studies of spermatogenic radiosensitivity were performed by analysis of the first cleavage metaphase and by dominant lethal tests in mice. Male mice were subjected to acute X-irradiation (500rad) and each male was then serially mated with two virgin females per week for six weeks. Chromosome aberrations were scored at the paternal chromosome sets in the first cleavage mataphases after fertilization. Spermatids were nearly twice as sensitive as spermatozoa to the induction of chromosome aberrations and dominant lethals, and chromosome-type aberrations were mainly induced. The profile of stage-specific chromosome aberrations induced by X-rays in male germ cells was different from that induced by chemical agents.抄録全体を表示PDF形式でダウンロード (980K) -
Motoe KATOH, Shigeo IWAHARA1983 年 58 巻 4 号 p. 345-351
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーA high dose (200mg/kg) of isopropyl methanesulfonate (iPMS) induced a high frequency of postimplantation loss in postmeiotic male germ cell stages, but the frequency of eggs with chromosome aberrations observed at the first cleavage metaphases was very low. Therefore, we suggest that the postimplantation loss in dominant lethal mutations induced by iPMS is mainly attributable to the alteration of subchromosome material at the first cleavage metaphases.抄録全体を表示PDF形式でダウンロード (283K) -
II. Induction of heritable translocationsNoriho TANAKA, Motoe KATOH, Shigeo IWAHARA, Koroku HASHIMOTO, Ichiro W ...1983 年 58 巻 4 号 p. 353-359
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーThe induction of heritable translocations with chemicals in postcopulation germ cells of female mice was investigated. In the methyl methanesulfonate (MMS)-treated group (100mg/kg), 14 partially sterile and 5 sterile males out of 118 F1 male progeny were found. In contrast, in the mitomycin C (MC)- treated group (3mg/kg and 4mg/kg) the frequencies were low. These results indicate that the yield of heritable translocations parallels the formation of chromosome-type aberrations at the first cleavage reported previously.抄録全体を表示PDF形式でダウンロード (254K) -
Makoto MUROFUSHI, Shohei NISHIKAWA, Tosihide H. YOSIDA1983 年 58 巻 4 号 p. 361-367
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーAll six sparoid fish species (Pagrus major, Evynnis japonica, Dentex tumifrons, Acanthopagrus schlegeli, A. latus and Sparus sarba) studied here showed a diploid chromosome number of 48. Although the total numbers of chromosomes in these species were identical, the numbers of the acrocentrics, subtelocentrics and submetacentrics were different from each other. Thus, they had different numbers of chromosome arms such as 50, 52, 58 and 60 (Table 2). Based on the karyotype analysis the sparoid species can be classified roughly into two groups according to the number of biarmed chromosomes; one of them had 2 or 4 biarmed chromosomes as found in P. major, E. japonica and D. tumifrons, and the other one had 10 or 12 biarmed chromosomes as seen in A. schlegeli, A. latus and S. sarba. The secondary constrictions were found in No. 4 chromosomes of two species (A. schlegeli and A. latus). Although a heteromorphic chromosome pair was found in No. 1 chromosomes of P. major and E. japonica, it can not be identified at present whether this heteromorphic pair is sex chromosome or not.抄録全体を表示PDF形式でダウンロード (311K) -
Hitoshi SUZUKI, Tosihide H. YOSIDA1983 年 58 巻 4 号 p. 369-372
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーThe sister chromatid exchange (SCE) in Chinese hamster D-6 cells was induced by treatment with the excess amounts of deoxyribonucleosides such as dA, dG, and dT or their mixtures. The induction of the SCE, however, was suppressed by additions of dC and combinations of the other deoxyribonucleosides with dC. These results suggested that SCEs could be induced by the inhibition of ribonucleotide reductase activity, namely, metabolic perturbation of deoxyribonucleotide synthesis. On the other hand, SCE was induced by hydroxyurea (HU) at about two times of control. SCE inducing by HU, however, was not suppressed by simultaneous addition of deoxyribonucleosides (dA, dG, dT, and dC). This result means that induction of SCE by HU was not due to the depletion of deoxyribonucleotides, but it might be due to any other factor which is unknown at present.抄録全体を表示PDF形式でダウンロード (168K) -
Kohji SHIRAISHI, Yasokazu HIRAI1983 年 58 巻 4 号 p. 373-375
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーLiver and pancreas mannosephosphate isomerase of the guinea fowl was examined electrophoretically. Three electrophoretic patterns, designated as A, AB and B, were observed in a closed population of the species (Galor strain). Mating experiments indicated that these phenotypes are controlled by autosomal codominant genes, which are symbolyzed as MPI-IA and MPI- IB. Of a total of 161 individuals examined, 59, 82 and 20 were classified as A, AB and B, respectively.抄録全体を表示PDF形式でダウンロード (120K) -
II. Formation of synaptinemal complexes in microsporocytesMichio ITO, Miyako H. TAKEGAMI, Shozo NODA1983 年 58 巻 4 号 p. 377-381
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリーAn achiasmatic meiosis is observed in microsporocytes of Fritillaria japonica group, in which paired chromosomes devoid of chiasmata are continuosly maintained through meiotic prophase. Experiments were aimed at examining whether the chromosome pairing is associated with normal synaptinemalcomplex (SC) structure. Examination in the electron micrscope of pachytene cells showed that the SC was present in all cross-sections through the chromosomes, and the SC seemed to be normal in appearance and dimension.抄録全体を表示PDF形式でダウンロード (652K) -
Tsuneyuki YAMAZAKI, Yoshinori MATSUO1983 年 58 巻 4 号 p. 383-386
発行日: 1983年
公開日: 2006/07/25
ジャーナル フリー"Inducibility" represents the effects of all the factors which control the amount of an enzyme production, amylase in this study, but does not contain the effects of the difference in the structure gene. "Inducibility", which turned out to be polymorphic in natural populations of D. melanogaster, was significantly correlated with fitness and responded positively to natural selection.抄録全体を表示PDF形式でダウンロード (188K)
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