遺伝学雑誌
Online ISSN : 1880-5787
Print ISSN : 0021-504X
ISSN-L : 0021-504X
46 巻, 5 号
選択された号の論文の9件中1~9を表示しています
  • YUZO KUROKI, MASAHIDE KURITA
    1971 年 46 巻 5 号 p. 295-300
    発行日: 1971年
    公開日: 2007/05/21
    ジャーナル フリー
    At interphase nuclei of Rumex acetosa, two Y-chromosomes and H-segments of certain autosomes usually reveal themselves as chromocenters. In each sex of the species, two different clones, one bear H-segment and the other no such segment, were studied for counting the chromocenters in relation to H-segment-bearing autosomes, to the Y-chromosomes and to both the autosomes and Y's.
    In female, the number of chromocenter corresponds to that of H-segment-bearing autosomes. In male, the chromocenters are more in number than the Y-chromosomes in one clone and also more than the Y's plus the H-segment-bearing autosomes in the other clone. Supporting our earlier study, the above facts seem to show that the heterochromatin of Y-chromosomes has a tendency to gather euchromatin granules into a mass which must be treated as a chromocenter, and that the heterochromatin of autosomes has no such a tendency.
  • HARUO CHIKUSHI, HIROSHI DOIRA, BUNGO SAKAGUCHI
    1971 年 46 巻 5 号 p. 301-307
    発行日: 1971年
    公開日: 2007/05/21
    ジャーナル フリー
    The dominant mutant “Retarded growth” (symbol Rg) was found as a gamma-ray induced phenomenon. It is characterized by a departure from the normal type representing distinctly delayed larval growth. The homozygote is completely lethal in embryonic stage.
    Linkage test showed the Rg locus to be in the third chromosome at 24.9. Further crosses with the recessive gene sm(N) gave without exception pseudo-dominantly manifested sm(N) character in Rg females. While the crosses with allelic sm(S) gave sm(S) character in only a part of Rg females, which is explained as due to a position effect. It is concluded from these results that Rg is not a gene mutation but a deletion of intercalary chromosomal segment. The left break is at 24.9 and the right break is just left by the sm(S) locus at 41.8. The deficit is about 17 units of the length of the third chromosome.
  • NORIAKI EBITANI
    1971 年 46 巻 5 号 p. 309-319
    発行日: 1971年
    公開日: 2007/05/21
    ジャーナル フリー
    Body weight of Drosophila ananassae at different developmental stages was measured under different nutritional and temperature conditions. Comparison of body weight was made among four different karyotypes, derived from a subterminal inversion In2L.
    Body weight of inversion heterozygotes was significantly heavier than that of homozygotes throughout all developmental stages under most of the experimental conditions. Larval weight increment per hour was larger in heterozygotes than homozygotes, especially in earlier larval stages.
    Heterozygote superiority was also true for nitrogen content, which was strongly correlated with body weight.
  • YASUO NAKAI, KOICHIRO TSUNEWAKI
    1971 年 46 巻 5 号 p. 321-336
    発行日: 1971年
    公開日: 2007/05/21
    ジャーナル フリー
    Esterase isozymes in all Aegilops species were analyzed by the disc gel electrofocusing method using pH 5-8 carrier ampholite. Details of the procedure and the reliability of isozyme separation using this method were described.
    Esterase zymograms of individual strains were analyzed (Fig. 2), and an average zymogram of all species was obtained (Table 2). Zymogram complexity, given by summation of activity scores of all bands in the average zymogram, was compared among all species; Ae. columnaris showed the greatest while Ae. bicornis and Ae. biuncialis showed the least complexity. When compared among the three ploidy levels; di-, tetra-and hexaploid, no significant difference was found.
    Intraspecific variability of the zymogram was expressed as sum of two variances attributable, respectively, to differences among the strains and to the interaction between the strains and isozyme bands. Variability was low in diploid and high in tetraploid species. However, two exceptional diploids, both belonging to the Sitopsis section, showed high variabilities. Hexaploid species showed few variations.
    Similarity of zymograms between all species was examined using correlation coefficients obtained from their average zymograms. In diploids, some species showed high positive correlations, while others showed negative correlations. Their genome homology, expressed by chromosome pairing in the F1 hybrids, was not related to zymogram similarity, indicating that the isozyme pattern is controlled only by a few genes. Zymograms of tetraploid species showed high correlations to those of either diploid ancestor. The epistasis relationship among esterase genes in five genomes was postulated as follows: Cu=S>C=M>D. Hexaploid species showed a close relationship to the tetraploid but not to the diploid ancestors.
  • SUNG LEE
    1971 年 46 巻 5 号 p. 337-344
    発行日: 1971年
    公開日: 2007/05/21
    ジャーナル フリー
    Caffeine induced a high frequency of chromatid aberrations in the cultured human leucocytes and the human embryonic cells in culture. The chromatid aberrations were predominantly gaps and breaks, and no exchange aberrations were observed. Experiments made by varying the interim between treatment and fixation, accompanied by the 3H-TdR labelling technique, showed that induction of damage was confined to the DNA-synthesis phase, in which the later part of the S phase was the most sensitive. Caffeine had no effect on the G1 and G2 phases. The rarity of exchange aberrations and the restriction of sensitivity to the DNA-synthesis phase may relate to the ambiguous results on the effectiveness of caffeine in the induction of dominant lethal mutations in laboratory animals.
  • I. LOCATION OF GENES AND VARIATION IN TETRA- AND HEXAPLOID WHEAT
    KOZO NISHIKAWA, MASAHIRO NOBUHARA
    1971 年 46 巻 5 号 p. 345-353
    発行日: 1971年
    公開日: 2007/05/21
    ジャーナル フリー
    For the purpose of showing homoeological relationship between chromosomes at the enzymatic level, α-amylase isozymes of germinated seeds of 27 ditelocentric lines of Chinese Spring wheat were analyzed with disc-isoelectrofocusing.
    Two triplicate genetic systems have been proved to specify six α-amylase isozymes out of 15 appeared on the zymogram, namely band 1 was controlled by a gene on the β-arm of chromosome 6D (Amy6D), band 2, band 3, band 11, band 13 and band 15 by a gene on the long arm of chromosome 6A, 6B, 7D, 7A and 7B (Amy6A, Amy6B, Amy7D, Amy7A and Amy7B), respectively. Three genes of each of group 6 and 7 were considered as homoeologous for one another, which might be derived from a gene of the primordial genome by gene mutation.
    Forty three varieties or cultivars of hexaploid wheat showed 13 different types of zymogram pattern of α-amylase isozymes and were divided into two clusters according to which of band 3 or band 4' they had, i.e. to Cluster 1 eight types having band 3 belong and to Cluster 2 five types having band 4'. Variation in zymogram patterns was concentrated on group 6 and 7 isozymes. Seven strains having band 10 were European wheat but Asian varieties or cultivars did not possess band 10.
    In tetraploid wheat (Emmer and Timopheevi group) band 1 specified by Amy6D and band 11 by Amy7D were absent. It is explainable based on that genome D is not present in tetraploid wheat. Genome A of Timopheevi group was apparently different from that of Emmer and hexaploid wheat in α-amylase isozymes.
    Genome specific shift of isoelectric point of α-amylase isozymes was found, i.e. those specified by genes of genome D took position at the most alkaline side, those of genome B at the acidic side and those of genome A between the two. This may have evolutionary significance.
  • YASUSHI TAKENOUCHI
    1971 年 46 巻 5 号 p. 355-360
    発行日: 1971年
    公開日: 2007/05/21
    ジャーナル フリー
    The chromosomes of two B. ezoana males were studied. One had 2n=34 (16II+XyP); and one, 2n=32. The latter corresponds to a former finding (15II+XyP). The 2n=32 specimen was a chromosomally polymorphic mosaic having 28 to circa 61 chromosomes. Cells with 32 chromosome (48.6%) were commonest.
  • NOBUO TAKAGI
    1971 年 46 巻 5 号 p. 361-363
    発行日: 1971年
    公開日: 2007/05/21
    ジャーナル フリー
  • TOMOAKI MUROTSU, TADAO HORIUCHI
    1971 年 46 巻 5 号 p. 365-368
    発行日: 1971年
    公開日: 2007/05/21
    ジャーナル フリー
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