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Volume 36, Issue 1-2
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Hikaru KUWADA1961 Volume 36 Issue 1-2 Pages 1-5
Published: 1961
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESS(1) Paper-chromatographic experiments were carried out in order to determine the kind of anthocyanins, and to clarify their genetical behaviours, using the flowers of amphidiploid and its parents.
(2) Material used were Abelmoschus esculentus (2n=124), A. Manihot (2n=68), F1 (2n=96) of the above two, and“Nori-Asa”(2n=192) which is an artificially raised amphidiploid between them.
(3) The results have shown that the coloring matters in esculentus consist of ilicicyanin, chrysanthemin (or idaein) and cyanidin, and that the pigments in Manihot are delphinidin 3-glucoside (or empetrin) and delphinidin together with all components appearing in esculentus.
(4) The coloring matters in F1 and amphidiploid were found to be identical, in spite of an appreciable difference in their chromosomal constitution. The number of pigment components in these two plants was equal to that of Manihot, but was apparently superior to that of esculentus plant.View full abstractDownload PDF (220K) -
Sohei KONDO1961 Volume 36 Issue 1-2 Pages 6-17
Published: 1961
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESSi) A general theory for the frequency distribution of the number of mutants per individual has been developed on the basis of proper assumptions.
ii) The conditions for leading to a Poisson distribution of the number of mutants have been obtained.
iii) The comparison of the theory with the experiments which disclosed an appreciable deviation from a Poisson distribution shows excellent agreement. The occurrence of mutants in a large cluster is also in good agreement with the calculated frequency.
iv) A method for estimating the number of germ cells present when treated with a mutagenic agent has been proposed. The estimated number of germ cells is in agreement with the observed number of the irradiated silkworm gonia.
v) A connection of cluster mutants and sample size of germ cells (used for recovery of mutations) per individual with the estimated mutation rate has been discussed.View full abstractDownload PDF (669K) -
Toshifumi TAIRA1961 Volume 36 Issue 1-2 Pages 18-31
Published: 1961
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESSSingle and double or triple eye color mutants of Drosophila melanogaster were used for the experiments. The relative amounts of eye pigments, extracted from heads without proboscis by means of“double extraction”method, were estimated by photometrical measurement. Several kinds of pteridines, which were contained mainly in eyes and testes, were separated by paper chromatography and their amounts were measured fluorometrically. Their relative amounts could be estimated by comparing them with each other.
The eye pigments of Drosophila are composed of three kinds, red, yellow and brown. Red and yellow pigments have been proved to be pteridine derivatives, and a metabolic pathway from yellow to red was suggested on the basis of experimental results. A metabolic relationship between several pteridines was indicated on the basis of the influence of various mutant genes on the amount of pteridines.
Since pteridines are located in eyes and in testes, a remarkable sexual difference was detected; their total amount in male bodies was about 20 times as large as in female bodies. The genic actions of both w and bw strains are assumed to block up the supply of the common pteridine precursor. The route of supply is more or less depressed by the action of ca, ry and Hnr-3 genes. The homozygous Hnr-3 fly was considered to have incomplete conversion of sepiapterin to tetrahydropterin, because of reduced activity of pterine reductase. The cl and Hnr-1 genes inhibit considerably the transformation of tetrahydropterin into red pigment, but the se gene blocks it completely. From all results, a scheme on pteridine metabolism of Drosophila was devised.View full abstractDownload PDF (851K) -
Yasuko TOYOFUKU1961 Volume 36 Issue 1-2 Pages 32-36
Published: 1961
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESSThe present study describes some polymorphic aberrations found in the salivary gland chromosomes of Drosophila immigrans which was based on three natural populations in Hokkaido.
The standard salivary gland chromosomes of D. immigransof Hokkaido are generally similar to those in Brazilian population according to the report of Freire-Maia et al. (1953).
In 384 larvae examined in this study, eight different types of chromosome aberrations (0.05 per larva) were observed in the second and the third chromosomes. The subterminal inversion in the right limb of the second chromosome was most frequent in occurrence (60.8per cent). There were two aberrations which were morphologically identical with those reported in Chiliean population by Brncic (1955).
In order to examine the frequency in occurrence of heterozygous inversions in the laboratory culture, brother-sister matings were carried out with a pair of flies with a subterminal inversion. The results showed that, during 10 mating generations, the ratio of the standard gene-arrangement to the heterozygous inversion was 1:1.View full abstractDownload PDF (809K) -
Tiharu Suto1961 Volume 36 Issue 1-2 Pages 37-54
Published: 1961
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESSSome of the salient findings of genetic studies on maize carried out over a period of twenty-two years since 1939 are herein presented. This period is divisible into two. In the first fourteen years, genic analyses of 27 mutant characters were mainly made at the Hokkaido University. In this period, 55 genes were analyzed, and linkage relationships of 39 out of these 55 were ascertained. Mapping of 18 of these loci on the maize chromosome map established was possible (Table 1). In the subsequent eight years, 1953 to the current year, researches were on the characteristics of oriental maize in relation to the expression of heterosis. This work was done at the National Institute of Agricultural Sciences, Hiratsuka.View full abstractDownload PDF (4071K)
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