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Volume 44 (1969)
- Issue 6 Pages 341-
- Issue 5 Pages 275-
- Issue 4 Pages 193-
- Issue 3 Pages 117-
- Issue 2 Pages 57-
- Issue 1 Pages 1-
Volume 44, Issue 4
Displaying 1-7 of 7 articles from this issue
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TOSHIHIKO OKADA, HISAKO TORII, SIGERU KUNO1969 Volume 44 Issue 4 Pages 193-205
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESS1. Biochemical characteristics of two types of thymine-less mutant of E. coli K12 with high and low thymine requirements (Thy20- and Thy2-) were compared.
2. The excretion of deoxyribose into the medium by Thy2- during thymine starvation was a unique character associated with the mutation of Thy20- to Thy2-, suggesting a deficiency of phosphodeoxyribomutase (Mut) and/or deoxyriboaldolase (Ald) whichparticipate in deoxyribonucleoside catabolism.
3. The mutation also results in change in the activities and inducibilities of thymidine phosphorylase (Tpp), purine nucleoside phosphorylase (Pup) and deoxyriboaldolase (Ald). Thy2- mutants were classified into four groups on the characters of these enzymes; 1) constitutive and may lack Mut, 2) inducible by thymidine or thymine starvation and lack Ald, 3a) non-inducible and may lack Mut, and 3b) non- or only slightly inducible and lack Ald.
4. Our data together with those of genetical studies show that a) the gene specifying all four enzymes participating in the catabolism of deoxyribonucleosides-Tpp, Pup, Ald, and Mut-might constitute an operon. The inducer for the operon is suggested to be dR-1-P. b) Accumulation of dR-5-P in the cells inhibits bacterial growth.View full abstractDownload PDF (1383K) -
YAW-EN CHU, HIROKO MORISHIMA, HIKO-ICHI OKA1969 Volume 44 Issue 4 Pages 207-223
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSF1 plants from 2, 728 crosses in total, made between strains of Oryza perennis Moench, O. sativa L., O. breviligulata Chev. et Roehr., and O. glaberrima Steud., were observed in a survey of hybrid sterility and other developmental abortions which constitute reproductive barriers. All the F1 plants observed showed no significant disturbance in chromosome pairing. Reproductive barriers were found as follows:
1) A low crossability due to deterioration of young F1 zygotes was found between the African form of perennis (subsp. barthii) and other taxa.
2) Vegetative weakness of F1 plants was frequently found among strains of glaberrima and breviligulata as well as in their hybrids with barthii and other taxa. It was sporadical among perennis and sativa strains.
3) F1 pollen sterility was found in various cross-combinations. Strains of glaberrima and breviligulata were inter-fertile with a few exceptions, and generally showed high F1 sterility with most perennis and sativa strains. Strains of perennis could be largely divided into four inter-sterile groups, Asian, African, American and Oceanian, suggesting that isolation by the ocean might have played an important role in phylogenetic differentiation. But some African (barthii) strains showed partial fertilities with others.
4) Embryosac fertility was shown by the percentage of anatomically normal embryosacs, which was comparable to the rate of successful back-crossing. No F1 hybrids were completely embryosac-sterile. They were divided into two groups, one in which pollen and embryosac fertilities were correlated and the other in which pollen fertility was near zero but embryosac fertility was apparently higher. Crosses between perennis-sativa and breviligulata-glaberrima series and some other distant crosses belonged to the latter group, in which embryosac tetrads tended to deteriorate.View full abstractDownload PDF (2731K) -
YAW-EN CHU, HIROKO MORISHIMA, HIKO-ICHI OKA1969 Volume 44 Issue 4 Pages 225-229
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSThree plants of the African form of Oryza perennis Moench (subsp. barthii) were tested for self-incompatibility by comparing self- and cross-pollinations. They were found to be partly self-incompatible. When selfed, the pollen grains germinated on the stigma, but a considerable number of pollen tubes did not grow further and showed swollen tips.View full abstractDownload PDF (905K) -
SUSUMU TAKAYAMA, YOSHIO OJIMA1969 Volume 44 Issue 4 Pages 231-240
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSCultured cells were exposed to each of 8 polycyclic hydrocarbons, and then illuminated with white light from a tungsten lamp. Carcinogenic hydrocarbons, benzo(a)pyrene, dimethylbenzacridine, methylcholanthrene, dimethylbenzanthracene, and benz(a)anthracene, were found to be much stronger in photosensitizing activity than noncarcinogenic ones, anthracene, pyrene, and acridine. Among the former compounds, benzopyrene is the strongest and benzanthracene the weakest. As far as the present experimental system is concerned, a clear positive association between photodynamic activity and carcinogenicity was found.
The cell-uptake of benzopyrene occurred in as fast as 1 second of incubation. When cells were illuminated, lysosomal staining with neutral red became markdely reduced and equivocal. Such alteration in lysosomal staining took place prior to the occurrence Table 2. Absorption spectra of polycyclic compounds used in the present experiment of any other detectable abnormalities. The photodynamic effect produced by the combined use of a photosensitizing substance and light is mainly, if not exclusively, due to the cell autolysis by the hydrolytic enzymes which were released from lysosomes as a result of photodynamic damage of their membrane.View full abstractDownload PDF (3241K) -
CHUBUN T. SATO, KEN-ICHI TOMOCHIKA1969 Volume 44 Issue 4 Pages 241-246
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSImmunoelectrophoretic analysis of the whole cell extract of Chlamydomonas reinhardtii by using the antiserum against the wild strain (21gr) demonstrated at least 14 antigenic components. When 11 mutants were compared with the wild strain, a certain difference in pattern was found in the number and the intensity of the precipitin lines Of the 14 immune-precipitin lines in the wild strain, 8 were common to all the strains tested, and the remaining 6 were variable according to the strain. The present data suggest the division of C. reinhardtii into some immunologically related groups.
The correspondence of the immunoelectrophoretic pattern to the genetically marked strain was examined. However, there was no indication of the association of antigenic specificities with any identified mutant characters. Any immunological differences in the mating type could not be found, either. However, the 2:2 segregation for the formation of some of the immune-lines suggests that these may be a single Mendelian character.View full abstractDownload PDF (589K) -
KAZUHIKO KOSUDA, OSAMU KITAGAWA, DAIGORO MORIWAKI1969 Volume 44 Issue 4 Pages 247-258
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSA total of 1, 822 second chromosomes were isolated from eight samples of a natural population in Ichinomiya, Yamanashi prefecture over a two-year period beginning in October, 1964, and the preadult viability of these chromosomes in homozygous condition was measured. No significant seasonal differences in the frequency distribution of chromosomes with various viabilities were detected. The average frequency of lethal chromosomes was about 15%. There were also no significant seasonal changes in the lethal allelic rate. Sterile males increased in frequency toward winter, while the proportion of fertile, inseminated females remained constant at about 87%. Yearly changes in the frequency of lethal allelism and a visible mutant (bw) were observed. The relation of these various observations to proposed mechanisms for the maintenance of genetic loads in natural populations of D. melanogaster was discussed.View full abstractDownload PDF (1182K) -
YASUO NAKAI, TEI TERAMURA, KOICHIRO TSUNEWAKI1969 Volume 44 Issue 4 Pages 259-270
Published: 1969
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSUsing the gel isoelectrofocusing technique, the zymograms of esterase from germinating seeds of 78 strains belonging to 26 species of Triticum and Aegilops were studied. Although some esterase bands were observed only in a limited number of species, seven bands (band 1-7) at pI 7.3, 6.8, 5.4, 5.4, 5.3, 5.2 and 5.1 were found in common in several species. Among these, bands 5 and 6 showed high density, almost, in all species, whereas densities of bands 3 and 4 varied greatly among the species studied. Activities of bands 1, 2 and 7 were low in most of the species.
Among the Triticum species, T. dicoccoides (4 strains), T. timopheevi (11 strains), naked emmer wheat (10 strains) and naked common wheat (9 strains) exhibited marked variations in zymograms, while einkorn wheat (6 strains), T. dicoccum (5 strains), T. araraticum (3 strains) and T. macha (13 strains) showed relatively little variations in their zymogram patterns. In order to know changes in the zymogram during domestication of a wild species, wild and cultivated species having the same genome formula were compared. T. monococcum (cultivated einkorn) showed more complex zymograms than T. boeoticum (wild einkorn), while T. timopheevi had simpler zymograms than its wild form, T. araraticum. T. dicoccum (cultivated spelt emmer) showed comparatively complex zymograms than that of T. dicoccoides (wild emmer), whereas T. durum and T. turgidum (cultivated naked emmer) had simple zymograms. Apparently, these results suggest that domestication of a species could result in both simplification and complication of the esterase zymogram.
The zymograms of two synthesized polyploids, namely, synthesized common wheat (genome formula AABBDD) and synthesized Ae. triuncialis (CCCuCu), closely resembled the sum of the zymograms of their parents, i. e., emmer wheat (AABB) and Ae. squarrosa (DD) in the former, and Ae. caudata (CC) and. Ae. umbellulata (CuCu) in the latter. However, they differed from those of the existing species of common wheat and Ae. triuncialis having the same genome constitution.View full abstractDownload PDF (2561K)
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