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Volume 35, Issue 10
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Minoru SHIMOTSUMA1960 Volume 35 Issue 10 Pages 303-312
Published: 1960
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSIntra- and interspecific hybrids were easily obtained from crosses among two races (C. No. 1 and C. No. 3) of C. colocynthis Schrad. and a variety (V. No. 1) of C. vulgaris Schrad..
Chromosome behavior of the three parental races was normal throughout the course of their meiotic divisions. Chromosome conjugations at metaphase I in PMC's of the three hybrids showed 11 bivlaents in about 50% of the cells. The remaining cells showed irregular chromosome associations such as multivalents, mostly trivalents, and univalents. The frequency of the cells with multivalent associations differs among the three hybrids (Fig. 1 and Table 2). Pollen fertility was found to be approximately 50% in all of them (Table 3 and Fig. 3).
Morphological characters of the three hybrids were compared with those of their parents (Table 4, Figs. 4, 5 & 6). C. colocynthis was dominant over C. vulgaris in stripe pattern of exocarp and taste and color of flesh. On the contrary, C. vulgaris was dominant over C. colocynthis in seed and exocarp color.
Although C. No. 1 and C. No. 3 belong to the same species they differ in many morphological characters. C. No. 3 was dominant over C. No. 1 in color and stripe pattern of the exocarp. On the contrary, C. No. 1 was dominant over C. No. 3 in seed color.
Leaves of the three hybrids are intermediate in shape between their parents. Seeds and fruits of the three hybrids are intermediate in size and weight between their parents.
Female flowers of C. No. 3 were not produced until the end of August, however, two hybrids, C. No. 1×C. No. 3 and C. No. 3×V. No. 1 produced female flowers normally as early as the beginning of July.
All hybrids showed hybrid vigor and were resistant to Fusarium wilt.View full abstractDownload PDF (2310K) -
Takeharu KANEHISA1960 Volume 35 Issue 10 Pages 313-320
Published: 1960
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSIn order to inquire into the possible role of flavine and pteridine in the tumor-formation of Drosophila melanogaster, early third-instar larvae of wild, v, tu, and v tu flies have been investigated with the following results: 1) Iso-xanthopterine and flavine, probably flavine-adenine-di-nucleotide, were extracted from the materials and identified electrophoretically, paper-chromatographically and fluoro-spectropho-tometrically. 2) Iso-xanthopterine and flavine were quantatively measured with the Beckman-spectrophotometer with the use of extracts from the paper-chromatograms of larvae which were cultured in synthetic media different in quantity of riboflavine and xanthopterine.
Melanotic tumor-incidence and viability of flies cultured in the media with different amounts of riboflavine and xanthopterine were also investigated.
Based on the results of the above experiments, the suggestion may be possible that flavine is intimately related to the tumorformation itself in competition with isoxanthopterine.
A scheme was presented to illustrated melanization, tryptophane metabolic pathway, and metal, flavine and iso-xanthopterine metabolisms in relation to the formation of the melanotic tumor in Drosophila.View full abstractDownload PDF (716K) -
Atusi ZENNYOZI1960 Volume 35 Issue 10 Pages 321-328
Published: 1960
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSF1 hybrids between Triticum Timopheevi (AAGG, 2n=28) and induced autotetraploid Aegilops squarrosa (DDDD, 2n=28) have been studied cytogenetically.
Among the 6 F1 plants obtained, 5 are observed to have 2n=28 chromosomes (AGDD) in PMC's as expected, while the remaining one has 2n=29 (AGDD+1).
The chromosome conjugations and their frequencies at the first metaphase of PMC's are shown in Table 1 for the F1 plants having 28 chromosomes and in Table 4 for that having 29. Namely, 0-1Iv+0-2III+5-10II+8-16I and 0- 1IV+0-2III+4-9II+10-17I are observed, respectively. The average values of chromosomes conjugations per cell are 0.0016IV+0.0428III+ 7.2476II+13.37I for F1's having 2n=28 and 0.004IV+0.466III+6.692II+14.202I for F1 having 29 (Table 2).
Among the maximum conjugations observed, 10II, 7 bivalents might have been formed by the autosyndesis between the chromosomes of induced autotetraploid Ae. squarrosa, and therefore the remaining 3 must have been produced by the autosyndesis of A and G genomes of T. Timopheevi on the basis of the partial homology of the chromosomes. The index of chromosome syndesis (Haga 1940) for the hybrids has been calculated by using the frequency of chromosome pairing except the D-D conjugation, 7II, namely the autosyndesis between A and G genomes, and the index varies from 3.86% to 5.83% with the individual, and 4.71% on the average (Table 2). The index is higher than that of the syndesis between A and B genomes of Emmer wheat (Kihara 1936, Kondo and Kamanoi 1958) and slightly higher than that of the autosyndesis between the chromosomes of A and G genomes in T. Timopheevi haploid plant (Riley and Chapman 1957), as shown in Table 4. It appears that the difference in the indices of syndesis for A-B and A-G genome chromosomes is due to the distinction between the B and G genomes.
Multivalent formations occur at the meiosis of these F1's (Tables 1 and 2), and the trivalents are produced by the pairing of the D-D conjugation of the induced autotetraploid Ae. squarrosa with either or both of the genomes of T. Timopheevi, and the tetravalents by the pairing of the said D-D conjugation with the A-G conjugation of T. Timopheevi.
The F1 plant with 2n=29 chromosomes has only one more chromosome of D genome than the eu-F1 plants, and this seems to be due to the formation of the gamete of DD+1 in the autotetraploid Ae. squarrosa.View full abstractDownload PDF (1430K) -
Yoshikazu MATANO1960 Volume 35 Issue 10 Pages 329-336
Published: 1960
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSThe present study deals with the development of a new subline in a rat ascites tumor, MTK-sarcoma II, with special remarks on the difference of chromosome pattern in the new and original stemline cells. The behavior and history of the two stem cells were also studied in serial transfers and under some experimental conditions.
The new subline is characterized by the tumor cells which are provided with originally occurring two remarkably large median chromosomes and one large submedian chromosome. The data based on the idiogram analysis suggest that the latter chromosome would probably be produced as a result of pericentric inversion in one of the larger chromosomes occurring in the original stem-cell.
After transplantation of a metastatic invasion, the alteration in frequency of the two types of stem-cells occurred with a maintenance of the stemlines. The original stem-cells characterized by two large median chromosomes made their appearance together with the new stem-cells at a very low frequency for a long period through serial transfers, and they were lost from vision in the sample from the 646th transfer generation. The original stem-cells were isolated however in a single cell clone.View full abstractDownload PDF (1022K)
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