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Volume 59, Issue 1
Displaying 1-8 of 8 articles from this issue
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BY H. T. IMAI, C. BARONI URBANI, M. KUBOTA, G. P. SHARMA, M. N. NARASI ...1984 Volume 59 Issue 1 Pages 1-32
Published: 1984
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSThe karyotypes of 94 species of Indian ants were examined. Their chromosome numbers range almost continuously between n=5 and 38, though the frequency distribution is bimodal with a remarkable antimode at n=11 and two modal points at n=10 and 15. Based on this bimodal distribution, Indian ants were classified into two groups: Lower-numbered species (n≤11) and higher-numbered species (n>11), the former being characterized by metacentric -rich karyotypes, and acrocentrics predominate in the latter. The three major subfamilies (Ponerinae, Myrmicinae, and Formicinae) showed a highly divergent distribution in chromosome number, ranging between n= 7-38, 6-35, and 8-27, respectively, suggesting a convergence in karyotype evolution of each subfamily, Another three subfamilies, of which only a few species were examined, had moderate or lower numbers, i.e., n=5-14 in Dolichoderinae, n=14 in Cerapachyinae, and n=12 in Dorylinae. We found four Robertsonian polymorphisms, two pericentric inversion polymorphisms, and four reciprocal translocations, three of which were fixed. Robertsonian polymorphisms were found only in higher-numbered species, while translocations were restricted to lower-numbered species. A possible biological significance for this nonrandom distribution of rearrangements is discussed with reference to karyotype evolution in ants.View full abstractDownload PDF (4322K) -
I. Protein polymorphism, lethal gene, sterility gene, inversion polymorphism and linkage disequilibriumTsuneyuki YAMAZAKI, Yoshinori MATSUO, Yasuhisa INOUEI, Yasubumi MATSUO1984 Volume 59 Issue 1 Pages 33-49
Published: 1984
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSGenetic parameters such as allozyme polymorphisms, lethal frequency, sterility frequency, inversion frequency and linkage disequilibrium were examined simultaneously in 780 second and third chromosomes, extracted from 2 natural populations of Drosophila melanogaster. The following results were obtained. 1) The average heterozygosities of 16 allozyme loci were 0.159 in the Akayu (AK) population and 0.181 in the Tanushimaru (TS) population. Little genetic differentiation was observed between populations (I=0.99). No linkage disequilibrium was observed between allozyme loci. 2) The frequency of the polymorphic inversion In(2L)t was 0.188 and 0.106 in the Akayu and Tanushimaru populations. That of the In(2R)NS was 0.115 and 0.049. That of the In(3L)P was 0.009 and 0.037, and that of the In(3R)P was 0.107 and 0.052. There were no significant linkage disequilibria between inversions. 3) The frequency of lethal carrying second chromosomes was 0.315 and 0.182 in the Akayu and Tanushimaru populations. Those on the third chromosome were found at a frequency of 0.327 and 0.305. The frequencies of sterile second chromosomes in Akayu were 0.147 and 0.127 in males and females, and of the third chromosomes, the respective frequencies were 0.093 and 0.084. Corresponding values for the Tanushimaru population were 0.091 and 0.07, and 0.0 and 0.084, respectively. Significant statistical associations were found between male and female sterility of the same shromosome, indicating pleiotropic gene action. 4) Negative or repulsion linkage disequilibria were found between inversions and allozymes, and between inversions. No evidence of frequency dependent selection with minority advantage was found.View full abstractDownload PDF (761K) -
Takashi NARISE, Kenji MIKASA1984 Volume 59 Issue 1 Pages 51-59
Published: 1984
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSIn order to examine the effect of one population on the emigration behavior of another population, seven wild strains of Drosophila melanogaster were used. The SI and KG strain were chosen as tester strain. Single and mixed strain experiments were done, in which two strains were mixed, and three kinds of relative frequencies in the mixtures-0.9, 0.5, and 0.1- were utilized. In mixtures of SI and its neighboring populations, emigration activity was decreased in comparison with the strain in the single condition, but the activity increased when distant populations were mixed. The same tendency was observed in mixtures of KG and other four strains. The increase or decrease in activity was mainly due to the stimulation or diminution of activity in the SI or KG strain. The A/B ratio was also calculated, and it was less than 1.0 in the mixtures of tester strain and its neighbouring populations, while greater than 1.0 in mixtures of tester strain and distant populations. Since A/B ratio is lower when genetically similar populations are mixed, this ratio may be useful to determine genetic relationships among populations.View full abstractDownload PDF (335K) -
Akishi FUKATAMI1984 Volume 59 Issue 1 Pages 61-70
Published: 1984
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSDifferentiation in low temperature resistance was investigated in two closely related species, Drosophila lutescens and D. takahashii. Drosophila flies at various developmental phases from an egg to an adult fly stage were chilled by low temperature of -3°C for six hours and the percent of hatching or hatchability for eggs, the percent of emergence for nonadult individuals and the percent of flies remaining alive after the treatment or the survival rate for adult flies were measured.
It has been found from this experiment that cold resistance is in general higher in D. lutescens than in D. takahashii. For instance, adult flies 10 days after emergence of D. takahashii were all killed by the chilling, while in D. lutescens nearly all flies of the same age survived the low temperature treatment. The intraspecific variation of cold tolerance in both species was in the order of pupae>aged eggs>young eggs>larvae, leaving the larvae the most susceptible.
Cold tolerance of adult flies in D. lutescens showed little variation in relation to ageing of flies, but in D. takahashii older flies proved to be more susceptible than younger ones.
Genetic investigation by means of the chromosome substitution has proved that the cold tolerance is closely associated with the ratio of D. lutescens chromosomes involved in hybrid flies, suggesting that the relevant genes may be distributed in either sex chromosomes and autosomes of D. lutescens. Thus, the successful propagation of D. lutescens in the northern parts of Japan islands in contrast to D. takahashii, distribution of which is strictly limited to the southern parts, may most probably be due to the genetic differences in cold tolerance, mainly of adult flies, during the winter time.View full abstractDownload PDF (414K) -
IV. Differentiation of oviposition force in the melanogaster species sub-groupTsuguhiko TAKAMURA1984 Volume 59 Issue 1 Pages 71-81
Published: 1984
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSThe tendency to insert eggs into substrate was compared among 6 species of the Drosophila melanogaster species sub-group by measuring the proportion of eggs deposited on filter paper placed on medium. Flies having a strong tendency to insert eggs avoid paper because it is impossible for them to insert eggs into the paper. D. melanogaster has a large genetic variation in this behavior. But two of its sibling species, D. simulans and D. mauritiana, showed no intraspecific genetic difference in the choice of oviposition sites; they laid almost all the eggs on the medium. Three other siblings, D. yakuba, D. teissieri, and D. erecta, also showed a strong tendency to avoid paper. The force to insert eggs into the medium was measured by changing the agar concentration of the medium. Among 6 species, the order in strength of the pressure to insert eggs is D. teissieri<D. melanogaster<D. yakuba<D. simulans<D. mauritiana <D. erecta. Evolutionary aspects of this behavior are discussed.View full abstractDownload PDF (495K) -
Yoshihiko FURUTA, Kozo NISHIKAWA, Takafumi MAKINO, Yukihiko SAWAI1984 Volume 59 Issue 1 Pages 83-90
Published: 1984
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSIn order to consider at chromosomal level the phylogeny of wheat, DNA content of 21 individual chromosomes was measured cytophotometrically at M1 or A1 of meiosis in monosomic plants and compared among seven strains belonging to six subspecies of common wheat, Triticum aestivum.
1) Nuclear DNA content at pollen tetrad did not differ at all among seven strains.
2) DNA content of individual chromosomes varied from chromosome to chromosome in any strain.
3) Significant difference was found among three genomes, A, B and D, the ratio being 1.14:1.21:1.00. This ratio apparently differed from those of two earlier reports based on nuclear DNA content of putative diploid ancestors (T. monococcum: Aegilops speltoides: Ae. squarrosa). The authors suggested diploid species of section Sitopsis, with a little higher DNA content than Ae. speltoides as B genome donor to polyploid wheat.
4) There was not significant difference among seven homoeologous groups, but homologous chromosomes.
5) Total DNA content of seven strains calculated from DNA content of individual chromosomes was very similar to one another, being clearly compatible with the results of nuclear DNA content at pollen tetrad.View full abstractDownload PDF (342K) -
Yoshiaki FUYAMA1984 Volume 59 Issue 1 Pages 91-96
Published: 1984
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSA unique male sterile mutant of Drosophila melanogaster, ms(3)K81 (3-91.3), has been discovered. The male homozygous for ms(3)K81 produces those abnormal sperm which are defective in syngamy but are still capable of activating eggs. The eggs activated by these sperm usually produce haploid embryos that die before hatching. But some of them, by restoring diploidy, undergo normal development to produce impaternate adults. This demonstrates that D. melanogaster has a capacity to reproduce gynogenetically.View full abstractDownload PDF (496K) -
I. The reduction of the embryolethality of methyl methanesulfonate by caffeineTetsuji NAGAO, Masahiro MIZUTANI1984 Volume 59 Issue 1 Pages 97-101
Published: 1984
Released on J-STAGE: July 25, 2006
JOURNAL FREE ACCESSEffects of caffeine on methyl methanesulfonate (MMS)-induced embryolethality and chromosomal aberrations in hepatocytes of mouse embryos were examined. MMS was given intraperitoneally but caffeine subcutaneously on day 12 of gestation. Embryolethality was checked on day 18 of gestation but chromosomal aberrations at 3, 6, 12, 18, 24, 36 and 48 hours after administration of drugs. The dose of MMS was chosen, which caused severe embryolethality but not any observed chromosomal aberrations. The simultaneous administration of caffeine reduced the embryolethality of MMS while the frequency of chromosomal aberrations increased significantly. The reduction of the embryolethality of MMS may be ascribe to the toxic effects of MMS which must be antagonized by caffeine.View full abstractDownload PDF (200K)
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