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Volume 50 (1975)
- Issue 6 Pages 433-
- Issue 5 Pages 361-
- Issue 4 Pages 283-
- Issue 3 Pages 179-
- Issue 2 Pages 99-
- Issue 1 Pages 1-
Volume 50, Issue 3
Displaying 1-11 of 11 articles from this issue
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AKIO MURAKAMI1975 Volume 50 Issue 3 Pages 179-187
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSMutagenic effects of ethyl methanesulphonate (EMS) on the cells in oogenesis of the silkworm (Bombyx mori L.) have been studied by a larval and pupal injection method. Germ-cells at the time of injection were from middle growth stage oocytes to pre-meiotic prophase I oocytes. Frequencies of mutations were estimated by the egg-color specific locus method using pe and re gene loci. A remarkable high mutagenicity was observed after EMS treatment of the late pupal prophase I oocytes. No marked mutagenicity of EMS was observed in larval growth stage oocytes. Simple mosaic mutants having mutant and non-mutant cells predominated in the progeny derived from EMS-treated late pupal prophase I oocytes. In this stage oocytes other types of mutations such as double mosaics having two mutant phenotypes, yellowish-white (pe) and red (re) cells, triple mosaics having three possible phenotypes, pe, re and +, and complete mutants were also observed. The results indicate that EMS might be mutagenic for pre-meiotic oocytes, egg pronuclei and cleavage nuclei.View full abstractDownload PDF (908K) -
SEI-ICHI MATSUI, MOTOMICHI SASAKI1975 Volume 50 Issue 3 Pages 189-204
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSSome cytological, biochemical and biophysical studies were made on the G-banding mechanism of chromosomes, using isolated metaphase chromosomes of the Chinese hamster. The results obtained are:
1. All G-banding techniques tested cause the loss of certain macromolecules including DNA and proteins, leading to an uneven distribution of chromatin substances. The amounts of such macromolecules resided in the G-banded chromosomes approximate the morphologically estimated genome size of the Giemsa-positive bands.
2. The acrylamide gel electrophoresis reveals that the banding procedures remove non-histone proteins of relatively larger molecular sizes.
3.The major non-histone proteins reside in the G-banded chromosomes represent relatively small molecules containing a large number of SS bonds.
4. The residual G-band chromatin shows higher Tm and hyperchromicities as compared to the extracted one, suggesting that DNA in the former is more stabilized.
5. A slight difference in the DNA base composition between the residual and extracted chromatins does not seem to account for the banding mechanism.
6. Removal of RNA and histone does not affect the band formation.
7. In conclusion, the Giemsa-positive bands represent relatively thermostable chromatins constituting of smaller non-histone protein molecules.View full abstractDownload PDF (2847K) -
1. SELECTION AND GENETIC ANALYSISJONG-KIL CHOO1975 Volume 50 Issue 3 Pages 205-215
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSThe phototactic behavior of a population, derived from 11 iso-female lines of D. melanogaster collected in Okinawa, Japan, was studied by using a maze apparatus. Directional selections for positive and negative phototaxis were performed for 35 generations. The realized heritability for the first 20 generations was estimated to be 2.3% and 2.7% for the positive and negative phototactic behaviors, respectively.
The response to selection for photopositive and photonegative directions advanced symmetrically for the early generations, but it was biased for the later generations.
The response of the photopositive population to the reverse selection was about two times stronger than that of the photonegative population.
The mean photoscores of hybrid populations maintained by disruptive selection and of hybrid populations between photopositive and photonegative flies at generations 27, 31 and 35 inclined gradually to photonegative side. In such populations, the polygenes manifesting the photonegative behavior was epistatic or partially dominant over the polygenes manifesting the photopositive behavior.View full abstractDownload PDF (956K) -
FUMIE SASAKI1975 Volume 50 Issue 3 Pages 217-233
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSImmunological phylogenetic relationships of the α- and β-esterases of Drosophila have been studied for 31 species from 13 different species groups of four subgenera. The results of immunodiffusion tests against anti-α and anti-β serum, which were prepared against α- and β-esterase of D. virilis respectively, revealed remarkable differentiation in both these esterases among Drosophila species. Eight species belonging to the subgenera other than the subgenus Drosophila to which virilis belonged, reacted with neither anti-α nor anti-β serum. The same situation was found for the species in the quinaria section of the subgenus Drosophila, with the exception only of multispina (funebris group) in which faint precipitin lines were found against only anti-α serum. Fly extracts from 12 species of the virilis section in the subgenus Drosophila cross-reacted with both anti-α and anti-β sera without exception. However, differentiation of esterases between species groups in the virilis section as well as differentiation between three species of the virilis group was proven to be based on (a) different esterase activity of the precipitin lines, (b) the formation of the spur and (c) on inhibition of esterase activity by antisera. The amount of cross-reacting materials in reference to β-esterase estimated in comparison with virilis is as follows: about one half in ezoana (virilis group), one eighth in hydei (repleta group, vivilis section) and zero in funebris (funebris group, quinaria section). In general β-esterase seem to differentiate more than α-esterases. Differentiation of Drosophila esterases disclosed here by immunological methods coincides well with Throckmorton's scheme of phylogenetic relationships based upon morphological and biochemical characters.View full abstractDownload PDF (3856K) -
TOSHIAKI KAMEYA1975 Volume 50 Issue 3 Pages 235-246
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSIn examining the influence of various substances on protoplasts it was found that high molecules of dextran sulfate had the effect of causing protoplast aggregation like gelatin. In order to distinguish one protoplast from another, the vacuoles of the protoplasts were stained with neutral red. When protoplasts of two different species were mixed in the dextran sulfate solution, they aggregated with each other at random. In the aggregated protoplasts between different species, they made cell walls and showed cell division at several times, but then they stoped their cell division and did not grow as colonies. It was thought their specificity appeared gradually in the process of cell division and development of cells into colonies, though it did not at early stages. Using dextran sulfate and gelatin, hybrid plants were induced from the aggregated protoplasts between green leaf and albino callus of haploid tobacco.View full abstractDownload PDF (5839K) -
FUMIO SUZUKI, MASAKATSU HORIKAWA1975 Volume 50 Issue 3 Pages 247-256
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSNutritionally deficient cells were detected and isolated from cultures of Chinese hamster hai cells by our replica plating method. The nutritionally sufficient characteristics (Ala+, Asn+, Pro+, Asp+, Hyp+) of a prototrophic clone isolated in the first survey, which was performed about one month after the cells were transferred to the complete medium from the original medium, were stable. On the other hand, the majority among the nutritionally deficient characteristics (Ala-, Asn-, Pro-, Ser-, Gly-, TdR-) of an auxotrophic clone isolated in the second survey, which was performed about one year after the cells were transferred to the complete medium, were unstable. Only the thymidine-deficient characteristics of this clone were stable, and the mean reverse mutation frequency of this characteristic was 4.7×10-6. These results indicate that epigenetic as well as genetic changes may be related to the changes in nutritional requirement of mammalian cells and that our replica plating method might equally detect the cells having apparently genetic characteristics altered by epigenetic as well as genetic changes.View full abstractDownload PDF (1051K) -
YOSHIHIKO FURUTA, KOZO NISHIKAWA, TAKABUMI MAKINO1975 Volume 50 Issue 3 Pages 257-263
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSFeulgen-cytophotometrical measurement of nuclear DNA content in 27 strains of Ae. squarrosa revealed intraspecific variation, which was continuous, the highest value being 1.23 times greater than the lowest. Mean DNA values in an increasing order were var. typica (435.5), var. meyeri (446.6), var. anathera (464.7) and var. strangulata (468.6) and an intermediate type between typica and anathera was between the two in mean DNA value, also.
Intravarietal differences were significant in all varieties measured except var. stragulata. Variation in nuclear DNA content of Ae. squarrosa may be caused by lengthwise duplications or deficiencies of small segments of almost all chromosomes.View full abstractDownload PDF (588K) -
YOSHIZANE MAEDA, TSUTOMU HASHIGUCHI, MANJIRO TAKETOMI1975 Volume 50 Issue 3 Pages 265-268
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSDownload PDF (481K) -
TAKAO K. WATANABE1975 Volume 50 Issue 3 Pages 269-271
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSDownload PDF (288K) -
KOJI MYOHARA, KOICHI HIWATASHI1975 Volume 50 Issue 3 Pages 273-275
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSDownload PDF (542K) -
TOKUHIKO MAKINO1975 Volume 50 Issue 3 Pages 277-280
Published: 1975
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSDownload PDF (817K)
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