Abnormality in size of the Y chromosome was observed in 6 out of 7 male patients with neuropsychiatric diseases. Mensural examinations revealed that the long Y chromosome in cases 1 to 4 corresponded in length to chromosomes of group 16-18. Case No. 5 had a short Y chromosome which was much shorter than the chromosome 22. Of special interest is that patients with neuropsychiatric defects here studied showed the anomaly in size of the Y, although current reports indicate that the unusual length of the Y seems to be not necessarily associated with phenotypical anomaly in man.
An investigation was made of the effects of fission neutrons on the induction of visible recessive mutations in early and in late gonial cells of the silkworm. The results were compared with those of our previous reports, in which 14MeV neutrons and 137Cs γ-rays were used. 1) Dose-mutation frequency curve for fission neutrons is essentially the same as that for other radiations, showing a slow rise in the lower dose range but a rapid rise in the higher dose range. 2) Mutation response to fission neutrons was almost similar for male and female gonial cells, although higher frequencies were observed for fission neutrons than for γ-rays or 14MeV neutrons. 3) When radiation doses producing a frequency of 10-3 of visible recessive egg-color mutations were used as a criterion, the relative biological effectiveness of fission neutrons to γ-rays was about 1.7 to 2.4 for early stage gonia and 3.0 to 4.2 for late stage gonia. Similar results have already been reported for 14MeV neutrons, although the values were smaller. 4) All the dose-frequency curves obtained in the recent series of our work with γ-rays, 14MeV neutrons and fission neutrons are given in the present paper to make them available for further investigations in this field.
To detect at least one desirable mutant with a minimum total number of X2-plants or of combined X1- and X2-plants, two methods were established as suitable in relation to tillers of X1-plants. They are: a type of the “one-plant-two-grain method” (method D2) and of the “one-plant-three-grain method” (method E3) in which one grain is taken from each of two or three heads of an X1-plant respectively. These methods have been evaluated by considering the probability that one or more plants with the mutant allele in homozygous recessive form will appear in the total X2-plants in relation to the number of heads per X1-plant and to the independent degrees of mutation among the heads of the X1-plant. The “one-plant-one-grain method” (method C) proposed by Yoshida (1962) is the best when the number of heads per X1-plant (t) is equal to or smaller than three and method C or D2 is the best when t_??_4. No single method is known to cover all of the advantages. However, methods D2 and E3 will be better than the “one-plant-two-grain method” and the “one-plant-three-grain method” proposed in the first report of this series when t_??_2 and t_??_3 respectively. Generally speaking, it does not seem advantageous to use the “one-ear-one-grain method”. especially the “one-ear-two-grain method” and the “one-ear-three-grain method”.
The damage to tumor cells following the application of Solarson, an arsenical medicine to remove warts, was cytologically studied in HeLa and HL-C cells in tissue culture. The abnormalities induced in cultured cells by the agent are: partial agglutination of chromatin, swelling or deformation of nucleoli, and the production of cytoplasmic inclusions. The pattern of response to Solarson was similar between HeLa and HL-C cells, while the effect was more severe in the former than in the latter at comparatively low concentration.
Among offsprings of Strain 056 of Japanese morning glory which is assumed to have dominant gene Blown (B) and recessive genes delicate (dl) and feathered (fe), and also those of Strain 058 assumed to have genes Blown and feathered, we found many individuals showing tumor-like shoot development at cotyledonary stage. As the result of the observation of those individuals, the coexistence of Blown and feathered genes in homozygous condition is considered to be connected with the occurrence of the tumor. In vitro tumor tissues grew slowly on modified White's agar medium but the addition of yeast extract stimulated the growth considerably. In the in vivo tumor tissues, we found irregular configurations of vascular elements.
PTC taste ability was studied in various populations in Formosa by using test paper method. Incidence of non-tasters is as follows: A) Formosan of continental origin 1) Fo-kien origin 5.29±0.32% 2) Kwang-tung origin 4.51±0.60% B) Native Formosan 1) Pepo (Plain population) Siraya population 7.72±0.46% 2) High-land populations a) Saisiyt 10.81±1.93% b) Bunun 10.07±1.77% c) Rukai 1.52±0.76% The remarkable variation observed among the high-land populations may be ascribable to genetic drift due to social and geographical isolation, since the incidence of non-tasters shows no correlation with ABO blood group distribution and geographical distance among these populations.