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Volume 60 (1985)
- Issue 6 Pages 531-
- Issue 5 Pages 391-
- Issue 4 Pages 273-
- Issue 3 Pages 167-
- Issue 2 Pages 81-
- Issue 1 Pages 1-
Volume 60, Issue 4
Displaying 1-10 of 10 articles from this issue
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Junpei ISHIGURO1985 Volume 60 Issue 4 Pages 273-280
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSA cycloheximide-resistant mutant which also displays coreversion of leu2-1 UAA and met8-1 UAG mutations was isolated and characterized in the yeast, S. cerevisiae. One of the ribosomal protein (L23) differed electrophoretically in the mutant strain from that of the parental one. Diploid cells heterozygous for the mutation contained both altered and normal proteins and gave rise to tetrads of 2:2 segregation for the protein alteration, indicating that a single structural gene coding for L23 protein was mutated. In the meiotic progenies, however, alteration of the L23 protein did not cosegregate with any phenotypes of cycloheximide-resistance or reversion of the nonsense mutations. Trisomic analysis was performed to determine the genetic locus for the L23 protein, suggesting that the gene may not be on the chromosomes I through XVI examined.View full abstractDownload PDF (1371K) -
D. M. LAMBERT, A. A. HARPER1985 Volume 60 Issue 4 Pages 281-291
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSIn October 1954, Mori and his collaborators isolated a number of wild-type strains of Drosophila melanogaster and placed then in constant darkness. We have investigated the mate recognition system of individuals from these strains by comparing them with control strains. Mating activity rhythms for each strain were determined by measuring their mating propensity. Deviation in mate recognition was measured at times when "eagerness" of the "dark" lines and their controls were comparable. Our results show that despite such a long period under unusual environmental conditions the mate recognition system of individuals from "dark" strains had not significantly changed from their controls.View full abstractDownload PDF (1223K) -
IV. Allozyme variability in Nepali and Kashmirian populationsOhmi OHNISHI1985 Volume 60 Issue 4 Pages 293-305
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSElectrophoretic analyses of nine enzymes in 15 Nepali and two Kashmirian populations of common buckwheat were conducted by horizontal starch gel electrophoresis. The Nepali populations maintained as much allozyme variability as other outcrossing annual plant species. They were polymorphic at the loci, ADH, 6-PGDH-1, PGM-2, MDH-1, MDH-3 and some populations were also polymorphic at the GOT-1 and GDH loci. The percentage of poly-morphic loci was 32.5% and the average heterozygosity was 0.077 on the average. No distinct local differentiation among the Nepali populations was found. The Kashmirian populations which probably came from the Nepali Himalayan region had less genetic variability. They lost the variant alleles at the ADH, 6-PGDH-1 and PGM-2 loci, probably during the spread of cultivation. The low level of allozyme variability previously found in Japanese and European populations may also be interpreted by the loss of genetic variability during the spread of cultivation.View full abstractDownload PDF (1218K) -
Hiroshi YOSHIMARU, Terumi MUKAI1985 Volume 60 Issue 4 Pages 307-334
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSThe polygenes affecting developmental rate were characterized and its role in natural populations was investigated. Using the second chromosome lines of Drosophila melanogaster in which genetic variation is entirely due to newly arisen mutations and those extracted from the Ishigakijima natural population, several experiments were conducted, and the following findings were obtained: (1) The minimum estimate of spontaneous mutation rate was 0.148 per second chromosome per generation. This estimate is similar to that of viability polygenes (0.14, Mukai 1964). (2) The maximum estimate of homozygous effect of a mutant polygene was 0.0095, which is slightly smaller than the average effect of viability polygenes (0.027, Mukai 1964). (3) The average degree of dominance of newly arisen mutant polygenes was 0.400. This is nearly equal to that of viability polygenes (0.41, Mukai and Yamazaki 1968). The average degree of dominance of the genes in question which experienced natural selection was estimated to be 0.150 in the Ishigakijima population. It is slightly smaller than that of viability polygenes (0.21, Tachida et al. 1983). (4) Positive genotypic correlations between developmental rates and viabilities were observed for not only the chromosomes having newly arisen mutations but also those extracted from a natural population. The above (1) and (4) may indicate that the change of developmental rate is a pleiotropic effect of viability polygenes. (5) The above findings suggest mutation-selection balance as the main mechanism of maintenance of genetic variation in developmental rate.View full abstractDownload PDF (2527K) -
Takahiro TAGUCHI, Yukimasa SHIRAISHI1985 Volume 60 Issue 4 Pages 335-345
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSThe rates of DNA chain growth in four Bloom syndrome (BS) and one normal B-lymphoblastoid cell lines (B-LCLs) were studied using DNA fiber autoradiography. Four BS cell lines were classed into two groups, one with high sister chromatid exchange (SCE) character, the other with normal (low) SCE. Hot pulse warm chase (hot-warm) labeling was used to measure the replicon sizes, and pulse labeling with three different durations (30, 60 and 120mins) was used to estimate DNA chain growth rates. There was no significant difference in the rate of chain growth per minute among all of the cell lines studied. The finding that there is no difference of DNA chain growth rate between normal and BS cells with both high and normal SCE which originated from the same blood sample strongly indicates that BS DNA chain growth is basically normal and is independent of the SCE character.View full abstractDownload PDF (3250K) -
Yoshihisa FUJIO, Patricia Liliana Gil KODAKA, Motoyuki HARA1985 Volume 60 Issue 4 Pages 347-354
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSStarch gel electrophoresis was carried out to estimate the degree of genetic differentiation and amount of genetic variability in a haploid layer, Porphyra yezoensis. Twelve isozyme loci were examined in three locations. Fst value which measure genetic differentiation was 0.623, indicating that the population structure of Porphyra yezoensis had caused more geographical genetic differentiation than many other diploid organisms. The proportion of poly-morphic loci was 0.333 and heterozygosity over 12 loci varied from 0.100 to 0.141 with a mean of 0.127. The overall mean is similar to those obtained for various diploid organisms. High levels of genetic differentiation and genetic variability in these haploid plants can be explained by their system of propagation.View full abstractDownload PDF (736K) -
Seido OHNISHI, Takao K. WATANABE1985 Volume 60 Issue 4 Pages 355-358
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSFour Drosophila species, D. baimaii, D. bicornuta, D, burlai and D, truncata, belonging to the montium species subgroup, were examined for the abdominal tergite coloration. Females show dimorphsim, light or dark, in coloration. In all species examined, the color dimorphism is regulated by two alleles of a single autosomal locus and the dark allele is dominant. Males of the first three species show monomorphic tergite coloration, either light or dark, while males of the fourth species, D. truncata, show the light/dark color dimorphism. Here again it is controlled by two alleles of a single autosomal gene and the dark allele is dominant.View full abstractDownload PDF (357K) -
III. Cytogenetical studies on F2, B1 and other hybridsNobumichi INOMATA1985 Volume 60 Issue 4 Pages 359-371
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSCytogenetical studies on F2, B1 and other hybrids obtained from the F1 hybrids between Brassica campestris and B, oleracea were carried out. The plants examined were classified in three types. The first type plants had 29 chromosomes in root tip cells. The second type plants had 38 chromosomes and the third type plants had other than 29 or 38 chromosomes. Among the first type plants, the range of pollen fertility was 0% to 96.6%, with mean 53.2%, and the frequency of PMCs showing 10II+9I, 11II+7I and 12II+5I were 36.2%, 32.6% and 15.9%, respectively. In the second type plants, the range of pollen fertility varied from 14.0% to 99.0%, with mean 73.6%, and the frequency of PMCs showing 19II, 18II+2I and 17II+4I were 71.5%, 17.2% and 7.7%, respectively. The range of chromosome number in root tip cells of the third type plants was 18 to 58 in 33 plants examined, and the range of pollen fertility varied from 0% to 98.0%, with mean 31.8%. Many types of chromosome configuration in PMCs were observed. The possibility of newtype plants of B, campestris, B, oleracea and B. napus was discussedView full abstractDownload PDF (1902K) -
Myat Myat THU, W. Tum LIN, Anthony SEBASTIAN, Tozo KANDA, Kin MAY1985 Volume 60 Issue 4 Pages 373-380
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSAn attraction to biologically different characters, breeding site and behavioural features between two Burmese taxa, malaria vector members of the Anopheles (An.) balabacensis complex obliged us to evaluate their genetic divergence by morphological, genetic, and cytogenetic investigations. One of the two taxa was one from Kwang-ka-thang, Mudon Township, Mon State, and the other from Ye-sit-kan, Taikkyi Township. Although these two taxa were morphologically identified as An. dirus, they had different characters in fringe spot on wings at 5.1, 5.2 and 5.2 to 6vein (after Christophers 1933, and Reid 1968) from An. dims. In hybridization tests between the two, the F1 hybrids had low fertility in males and was revealed the existence of an inversion in 3R and some asynaptic segments. A distinct difference in the electrophoretic banding pattern of alphaesterase was found between the two. These results indicated that not a small amount of divergence occured between the two taxa.View full abstractDownload PDF (1751K) -
Tozo KANDA, Takiko MATSUNARI, Kenji TAKAI, CHEONG, Weng Hooi, LOONG, ...1985 Volume 60 Issue 4 Pages 381-386
Published: 1985
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSHybridization tests were performed between a morphological species, Anopheles (An.) takasagoensis elevated by Peyton and Harrison (1980) and four other taxa of the An. balabacensis complex (Kanda et al. 1983). From these tests validity of An. takasagoensis could be assessed and its phylogenic relationships to the following taxa were revised. The taxa used were: A taxon from Taiwan (TSG), the same colony of which was used for morphological identification by Peyton and Harrison (1980), two taxa from Kanchanaburi (KCH) and Chantaburi (CTB) in Thailand, and two taxa from Perlis (IMR) and Kotabelud, Sabah (KTD) in Malaysia. From these tests, the crosses between TSG and KTD yielded both fertile sexes of F1 hybrids. This meant lack of reproductive isolation between these two taxa. Results of other crosses between TSG and the other three taxa, KCH, CTB, and IMR showed a similar divergence to those of the crosses within the An. balabacensis complex. Therefore, An. takasagoensis is not a separate species from the balabacensis complex.View full abstractDownload PDF (520K)
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