A Study of the Somatic Chromosomes of Rats

Tanaka, Tatsuya

doi:10.1508/cytologia.18.343

Cited by 21 publications

(6 citation statements)

References 11 publications

(7 reference statements)

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“…Somatic polyploidy, that is, so-called polysomaty has been reported in the roottips of plants and animal tissues by numerous workers (Witkus and Bergner 1947;Witkus 1946,1950;Duncan 1945;Therman and Timonen 1951;Boothroyd and Walker 1952;Tanaka 1953;Ono and Sakai 1952;Kato 1955), but a phenomenon of "complex chromosome mosaics" as it is called by Frankhauser (1945), containing at meiosis a mixture of cells with normal diploid and various aberrant chromosome numbers in the same anther-loculus, has attracted no attention of cytogeneticists and plant breeders until such aberrant PMC's have been found with considerably high frequency in the progenies of wheat pentaploid hybrids by Love (1938). However, the rare occurrence of one or a small group of PMC's with less than the normal number of chromosomes has been reported earlier in the normal varieties and hybrids of wheat.…”

Section: Discussionmentioning

confidence: 99%

Chromosome-mosaics Observed in a Variety of Wheat, “Shirahada”

Watanabe

1962

The Japanese journal of genetics

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When the meiotic indices of wheat varieties were examined to serve the breeding program of the future, the author's attention was attracted to a variety called "Shirahada ", since it shows a very low meiotic index (56.55%). With the aim of making clear this cause, a cytological study was carried out on this variety.This paper deals briefly with the results obtained. Material and MethodsThe seeds of a variety of common wheat, " Shirahada " (Triticum vulgare Vill. 2n=42), used in this experiment, were presented by Mr. Ootani, the Head of the Wheat Breeding Laboratory, Tohoku National Agricultural Experiment Station. These had been preserved for a long time in the experimental field of his laboratory.The author wishes to express his sincere thanks to Mr. Ootani for his kindness.In the first year of this experiment, a population of 50 plants were grown in the field in the usual way, and after harvest the seed-fertility and the morphological characters were measured for all plants.On the basis of this result, five plants altogether, one with the highest fertility, two with low (including one with the lowest fertility), and two with pubescent hairs on the glumes, were selected for the cytological studies of the following year. The latter two plants with pubescent hairs on the glumes belonged to the intermediate class of fertility. Thus, the self-pollinated seeds of these five plants respectively were sown in the field, and from the plants which matured, 25 plants altogether, five plants from each one, were selected at random and from each plant the young anthers, which attained to the meiotic stage, were collected and fixed by acetic-alcohol

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Section: Discussionmentioning

confidence: 99%

Chromosome-mosaics Observed in a Variety of Wheat, “Shirahada”

Watanabe

1962

The Japanese journal of genetics

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“…The chromosome constitution of normal mitotic cells of the rat was reported by several investigators (Sachs 1952, Makino and Hsu 1954, Yosida 1955, Tj io and Levan 1956, Tanaka and Kano 1957. Though they agree on 2n=42 as the normal chromosome number of rats, the numbers of V-, J-and rod-shaped elements belonging to the karyotype are different by the author.…”

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confidence: 74%

“…There are different opinions on the morphology of the sex-chromosomes. Hsu (1954), Yosida (1955), Tanaka and Kano (1957) reported that the X-and Y-chromosomes are of Jshape, while Tjio and Levan (1956) described them to be rod-shaped. In order to identify the sex-elements, the chromosomes were arranged for each group according to their size (Figs.…”

mentioning

confidence: 99%

Chromosomal Alteration and Development of Tumor, IV. Comparative Idiogram Analysis in Cells of Normal Rat Liver and Rat Ascites Hepatoma No. 7974

Yosida

Ishihara

Odashiro

1960

The Japanese journal of genetics

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“…I n this connection, it is interesting to know that the ordinary tissue cells taking important part in growth also show a simpler relationship. In the cytological study of the regenerating rat liver, Makino and Tanaka (1953~) and Tanaka (1953) have found that, although there is a wide variation of the chromosome numbers in the liver cells of adult rats during restoration after partial extirpation, the most frequent chromosome numbers fall into the following three ranges: the diploid range (36 to 46 chromosomes), the triploid range (59 to 68 chromosomes), and the tetraploid range (78 to 89 chromosomes). The cells of the diploid range exist always in the highest frequency, and they then play a significant role in the regenerating rat liver, with cooperation of the cells of tetraploid and triploid ranges, which appear in more reduced percentage than the former.…”

Section: Mtk-it/mentioning

confidence: 99%