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Volume 52 (1977)
- Issue 6 Pages 417-
- Issue 5 Pages 327-
- Issue 4 Pages 261-
- Issue 3 Pages 171-
- Issue 2 Pages 87-
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Volume 52, Issue 5
Displaying 1-9 of 9 articles from this issue
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SACHIKO ITO1977 Volume 52 Issue 5 Pages 327-340
Published: 1977
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESS1) The structure of the nuclei in the silk gland cells of the silkworm, Bombyx mori, was investigated with special reference to the fine structure of the sex-heterochromatin body (SB), using both diploids and experimentally induced polyploids.
2) Microscopic observations revealed that the SB was not a homogeneous mass, but it was surrounded by a layer of chromatin substances formed by the coiling and folding of fibrils.
3) The SB was clearly observed in the silk gland nuclei in acetic orcein squashed preparations, being 100% in the female (SB1) and 0% in the male (SB0) in diploids. In the tetraploids, the female nucleus had two SBs (SB2), and the male nucleus contained no SB (SB0).
4) On the observation of the segregation of the number of the SB in triploid offsprings from the backcross of the tetraploid female, it was revealed that the ratio of SB2:SB1:SB0 was 1:4:1. The behavior of sex chromosomes in meiosis of the tetraploid female was considered according to the above results.
5) Using triploid offsprings from the strain having a translocated Y chromosome marked with visible genes, it is apparent that the SB is corresponding to a Y chromosome.View full abstractDownload PDF (4394K) -
AKISHI FUKATAMI1977 Volume 52 Issue 5 Pages 341-356
Published: 1977
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSEnzyme polymorphisms in natural populations of a semidomestic species, Drosophila lutescens, were studied. Electrophoretic techniques were employed to investigate allelic variations at four enzyme loci (Est-α, Est-β, Acph and Mdh) in twenty-five natural populations and at other four enzyme loci (Me, Idh, G6pd and Adh) in three to five populations. The most frequent allele at a given locus was generally the most frequent allele in all populations, and the allelic frequencies at six dimorphic loci showed a remarkable similarity from population to population. A comparison of genetic distances (D by Nei) among twenty-one populations estimated on the basis of the allelic frequency for four enzyme loci surveyed showed little difference, giving an average distance of 0.0079. Glucose-metabolizing enzymes such as Mdh, Me, Idh and G6pd were less genetically variable than non-glucose-metabolizing enzymes (Est-α, Est-β, Acph and Adh).View full abstractDownload PDF (1411K) -
HIROKO MORISHIMA, H. I. OKA1977 Volume 52 Issue 5 Pages 357-372
Published: 1977
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSTo look into the microevolution of weed populations in copper-polluted rice fields, we have been engaged in observations of weed communities. This paper deals with the results so far obtained in the barnyard grass (Echinochloa oryzicola, 4X and E. crusgalli, 6X). A total of 210 barnyard grass strains (progenies of single plants) collected from copper-polluted (25-310ppm) and control (1-18ppm) fields were tested for copper tolerance and other characters. Copper tolerance was evaluated by the ratio of performance in copper-treated plot to that in control (no copper) plot, mainly in gravel culture and partly in water culture. The 4X species tended to be more tolerant than the 6X species. It was also found that 6X strains resembling the 4X species morphologically had higher tolerance than typical 6X strains. In both species, the populations in polluted fields showed a higher frequency of tolerant plants or a higher mean tolerance than those in control fields. But the populations were polymorphic not only morphologically but also in copper tolerance. There were tolerant plants in normal fields and sensitive plants in polluted fields. The tolerant plants were generally small in the size of various organs and inferior in performance when tested in normal conditions. They were also inferior in competitive ability. The tolerant strains showed a lower copper content in the leaves and stems than normal strains in the copper-treated plot of gravel culture. The data were largely comparable with those reported by British workers in perennial grass species growing on strongly polluted sites, though the level of copper pollution in Japanese rice fields was much lower.View full abstractDownload PDF (1608K) -
TOKI-O YAMAMOTO1977 Volume 52 Issue 5 Pages 373-377
Published: 1977
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSA few Ginbuna, Carassius auratus langsdorfii, with nacreous-like (tomeirin-modoki) scaleness (symbolized ne) have been collected in upper reaches of the Tempaku river. Matings of a male nacreous-like fish with a matt Shubunkin (TT) female and a Wakin (tt) female have been made. It was found that nacreous-like scaleness is autosomal and controlled by a new mutant gene (ne) which is independent from the t-alleles of the goldfish.View full abstractDownload PDF (863K) -
III. ELECTROPHORETICAL STUDIES ON PEROXIDASE ISOZYMESARMANDO GARCIA, KOICHIRO TSUNEWAKI1977 Volume 52 Issue 5 Pages 379-386
Published: 1977
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSComparison of the peroxidase zymograms of the avocado, Persea americana between states from which a large number of strains were collected indicated that the strains from Michoacan, Mexico, Morelos, Puebla and Veracruz have 15, 13, 10, 12 and 12 active regions in the zymograms, respectively. The form having activities at more regions of zymograms would be regarded as more advanced ones than those possessing lower number of active regions. The percentage of strains in which statistically significant variation of zymograms within strains were found was high in Puebla (60.0%), Michoacan (43.1%) and Veracruz (37.4%). Also these states are the major places where avocado is cultivated more abundantly. Considering the higher frequencies of strains having significant differences of peroxidase zymograms within strains and lower number of active regions in the zymograms, the Puebla-Veracruz region was postulated as the possible center of the origin of the Mexican type of avocado. Archeological evidences found in the Valley of Tehuacan in Puebla, and the fact that P. schiedeana and P. floccosa, semicultivated and wild relatives of P. americana, respectively, grow in the Puebla-Veracruz area support this postulation.
Differences of peroxidase zymograms between Mexican, Guatemalan and West Indian types were also found to be highly significant. From the frequency of strains which showed significant variations within strains (62.5%, 50.0% and 39.1% in Guatemalan, West Indian and Mexican types, respectively), it was presumed that Guatemalan type is the most ancient form.View full abstractDownload PDF (795K) -
WATARU TESHIROGI, SHUN-ICHI SASAKI1977 Volume 52 Issue 5 Pages 387-396
Published: 1977
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSBy using the squash method, researches on the karyotype of Phagocata teshirogii and chromosomal variations found in neoblasts of regenerating pieces have been carried out. Observations were also made on the meiotic divisions of primary spermatocytes and oocytes.
The chromosome number of this species was 2n=24 and n=12. The karyotype consisted of 5 pairs of metacentric chromosomes, 1 pair of subtelocentric and 6 pairs of submetacentric chromosomes (Table 2). Chromosome No. 1 is particularly large. Chromosome No. 2 is medium in size, while all the others are distinctly small (Fig. 3). Although many neoblasts in regenerating pieces have the chromosome number of 2n=24, some others have different chromosome numbers. This finding seems to support Chandebois' view that various kinds of abnormal cell division, such as amitosis, budding and endomitosis, occur in neoblasts during regeneration (1965, 1976). No abnormality in chromosome number was found during the meiosis of spermatocytes and oocytes.View full abstractDownload PDF (2528K) -
TAEKO SHIGENOBU, SADAO SAKAMOTO1977 Volume 52 Issue 5 Pages 397-401
Published: 1977
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSDownload PDF (1016K) -
E. INAGAKI, K. FUJIKAWA, T. MIYAMOTO, Y. TERANISHI, Y. NAKAO1977 Volume 52 Issue 5 Pages 403-406
Published: 1977
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSDownload PDF (354K) -
KAJURO KOMEDA, YUTAKA MIZUMA, YOSHIO OKI1977 Volume 52 Issue 5 Pages 407-411
Published: 1977
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSA type of aliesterase designated as band D, was separated by starch-gel electrophoresis, and effects of thyroid hormone on its enzyme activity were examined in two inbred strains of mice. The staining intensity of band D enzyme in serum of C3H/HeJ strain of mice was apparently stronger in thyroidectomized mice than in untreated normal mice. It diminished extremely in the thyroidectomized mice when L-thyroxine was given. The thyroid hormone had the same effect on male and female mice. The activity of band D enzyme was absent in female and male mice of SS strain and did not appear after thyroidectomy.View full abstractDownload PDF (1139K)
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