著者

大西 近江 長久保 有之

出版者

日本遺伝学会

雑誌

遺伝学雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.57, no.6, pp.641-650, 1982

被引用文献数

3 5

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Allelism tests among 15 independently established dwarf lines revealed that five loci are involved in dwarfism in common buckwheat. They are designated dwA, dwB, dwC, dwD and dwE. The frequencies of dwarf mutants at four loci, dwA, dwB, dwC and dwD were investigated in three Japanese populations, Iwate, Togakushi, Higashi-Iyayama, by using four representative homozygous lines as the testers. The frequencies varied slightly among the populations, but on the average they were 0.235%, 0.067%, 0.294% and 0.196% for the dwA, dwB, dwC and dwD loci, respectively. These low allele frequencies imply that the recurrent mutation is balanced by selection against the dwarf alleles. This conclusion was confirmed by supplemental data on the frequency of dwarf mutants per gamete and a field survey of dwarf homozygotes in randomly mating populations in farmer′s field. Approximately 0.50% of the gametes contain a dwarf allele, whereas the incidence of dwarfism in the randomly mating populations was only 4.25 ×10^-6. The latter estimate was based on a study of more than 3 million plants.

著者

大西 近江

出版者

日本遺伝学会

雑誌

The Japanese journal of genetics (ISSN:0021504X)

巻号頁・発行日

vol.68, no.4, pp.303-316, 1993-08-25

参考文献数

28

被引用文献数

4 20

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Allozyme variability at 19 loci affecting 12 enzymes was analyzed electrophoretically in 21 populations from Europe and six populations from the silk road. Most of the populations were polymorphic at seven loci, <i>Dia-2</i>, <i>Got-2</i>, <i>Mdh-1</i>, <i>Mdh-3</i>, <i>Pgm-1</i>, <i>Pgm-2</i> and <i>Sdh-1</i>. As compared with Chinese populations, European populations have completely lost variability at <i>Adh</i> and <i>6-Pgdh-1.</i> Populations from southern Europe have less variability than those from other parts of Europe. They have lost variability at <i>Pgm-2</i> and have a greatly reduced frequency of the F allele at <i>Mdh-1</i>; occasionally, however, they show an increase in the frequency of the U allele at the <i>Got-2 </i>locus. Southern European populations show an increase in the <i>det</i> allele and in grey colored varieties. As a group, European populations show the smallest genetic distance with populations from the silk road and northern China. Combining these genetic findings with written documents and archeological evidence, I conclude that European buckwheat came from northern China via the silk road, and that it changed in many respects within the last 500 years.<br>

著者

榎本 中衞

出版者

日本遺伝学会

雑誌

遺伝學雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.5, no.1, pp.49-72, 1929

被引用文献数

4

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(1) 茨城縣農事試驗場に於て甞て水稻糯品種「愛國糯」に年々少數宛の粳粒を混生する事實あり。著者は其材料の一部を得て系統栽培を行ひ次に示す事實を確めたり。<br>(a) 前記材料水稻品種愛國糯は年々少數宛の粳粒を混生す。其歩合は 1926-0.67%, 1927-0.16%, 1928-0.29%, 合計-0.44%なり。而して此突變粳の發現歩合は系統に依りて著しき變異を示し (合計M&plusmn;&sigma;=1.01&plusmn;1.86) 不稔程度高き系統に於て寧ろ發現歩合高き傾向を示したり。<br>(b) 突變粳合計180粒に就て試驗せるに、すべて其翌代に於ては粳糯に分裂し其比は大約 3:1 に近し(糯歩合24.20%, D/P.E. 25%として2.76, 24%として0.69)。即ち突變粳は粳糯性につきてヘテロ状態にあり、且粳は糯に對して優性なるを示す。<br>(c) 突變粳の翌代の粳粒につき其次代を檢したる結果粳糯分裂系統と粳固定系統との割合は大約2:1に近し、(粳固定系統歩合31.56%, 理論歩合34%としてD/P.E.=0.89)<br>(d) 分裂系統に於ける粳糯分裂比は、其偏差を考ふるときは正しく3:1ならずして極少量の偏差を示す。即ち糯歩合を25%とするときはD/P.E=10.58にして偏差著しく大なるに反し之を24%とするときD/P.E=2.25にして偏差小なり。然るに前記分裂比は系統に依りて著しき變異を示し糯粒歩合を24%とするも尚偏差著しく大なる系統あり。<br>(e) 突變粳より生じたる粳固定系統に於ては糯粒を生ずることなし。即ち此場合に於ては逆轉化(Reversion)の現象を認めず。<br>(f) 1928年糯系統植物の花粉につき沃度反應に依りて花粉澱粉の粳糯性を檢したり。其結果愛國糯には約0.104%の粳花粉を混生することを認めたり(60頁附圖參照)。<br>(2) 上記の實驗結果に依れば、愛國糯に於て粳粒を混生するは、粳糯性を支配する遺傳因子(粳をGとし糯をgとす)に於て常に少數%のg&rarr;Gなる因子突然變異起るに依る。<br>(3) 此場合に於ける突然變異は恐らく配偶子形成のときに現はるものなるべし。如何と衣れば營養組織の細胞分裂のとき起るものとせば糯植物並にヘテロ粳植物の兩者に於ける粳粒の分布こ就き所謂モザイツクのもの存すべし。然るに本實驗の範圍内に於ては未だかくの如きモザイツク状植物を發見せられず。<br>(4) 配偶子に於ける粳粒歩合(<i>x</i>) (即ち突然變異歩合) を基礎とし之を實驗價0.10% となし、(1) 接合子に於ける粳粒發現歩合(2) 同上ホモ粳粒歩合、(3) 粳糯分裂比(4) 分裂系統と粳固定系統の割合等を計算したり。此數値は1928年に於ける實驗結果と可成よく一致せり。(63頁 參照)。<br>(5) 粳糯分裂比に於ける糯粒の不足は前記の如きg&rarr;Gなる優性因子突然變異に依つて當然起るべく、且此場合糯粒の著しく不足するものは不稔程度高き系統なるは恰も突變粳の發現歩合が不稔程度高き系統に多き傾向を示す事實と一致するものなり。即ち粳粒の發現歩合引いては粳糯分裂比に於ける糯の不足は共に不稔程度と關係するものゝ如し。然れども粳糯分裂比に於て系統に依り糯歩合の過多なる場合あり、此等は前記の突然變異を以て説明する能はず他に何等か粳糯分裂比を亂す原因の存在することを示すものなるべし。

著者

Motoo KIMURA

出版者

The Genetics Society of Japan

雑誌

遺伝学雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.66, no.4, pp.367-386, 1991 (Released:2006-06-10)

参考文献数

67

被引用文献数

98 172

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In sharp contrast to the Darwinian theory of evolution by natural selection, the neutral theory claims that the overwhelming majority of evolutionary changes at the molecular level are caused by random fixation (due to random sampling drift in finite populations) of selectively neutral (i.e., selectively equivalent) mutants under continued inputs of mutations. The theory also asserts that most of the genetic variability within species at the molecular level (such as protein and DNA polymorphism) are selectively neutral or very nearly neutral and that they are maintained in the species by the balance between mutational input and random extinction. The neutral theory is based on simple assumptions, enabling us to develop mathematical theories based on population genetics to treat molecular evolution and variation in quantitative terms. The theory can be tested against actual observations. Neo-Darwinians continue to criticize the neutral theory, but evidence for it has accumulated over the last two decades. The recent outpouring of DNA sequence data has greatly strengthened the theory. In this paper, I review some recent observations that strongly support the neutral theory. They include such topics as pseudoglobin genes of the mouse, αA-crystallin genes of the blind mole rat, genes of influenza A virus and nuclear vs. mitochondrial genes of fruit flies. I also discuss such topics as the evolution of deviant coding systems in Mycoplasma, the origin of life and the unified understanding of molecular and phenotypic evolution. I conclude that since the origin of life on Earth, neutral evolutionary changes have predominated over Darwinian evolutionary changes, at least in number.

著者

鈴木 仁 HOSODA Tetsuji SAKURAI Susumu TSUCHIYA Kimiyuki MUNECHIKA Isao KORABLEV Vladimir P.

出版者

Genetics Society of Japan

雑誌

The Japanese journal of genetics (ISSN:0021504X)

巻号頁・発行日

vol.69, no.4, pp.397-406, 1994-08-25

被引用文献数

7 10

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We analyzed the restriction fragment length polymorphisms in the spacer regions of ribosomal DNA (rDNA), using twelve restriction enzymes, to examine whether the Iriomote cat is related to the leopard cat (<i>Felis bengalensis</i>). A restriction map for each taxon was constructed and the major taxon-specific types of repeating unit (repetypes) were characterized on the basis of the arrangements of restriction sites. The Iriomote cat and the leopard cat share a common repetype but this repetype is different from that of the domestic cat (<i>F. catus</i>) with an estimated sequence divergence of 1.5% and from that of the ocelot (<i>F. paradalis</i>) with an estimated sequence divergence of 2.5%. These results indicate that, phylogenetically, the Iriomote cat is closely related to the leopard cat and that the ancestral population moved from the continent to Iriomote Island quite recently. The rDNA arrays of the leopard cat exhibit considerable intragenomic size-variation, which is thought to have emerged as a result of differences in numbers of repeated DNA segments, whereas the extent of such size-variation is much lower in the rDNA of the Iriomote cat. It appears that, even though migration of the Iriomote cat occurred relatively recently, the population has diverged to some extent from its continental counterpart, perhaps via fixation of preexistent intraspecific variations rather than by generation of new variations.<br>

著者

市川 定夫 今井 敏彦 中野 篤

出版者

Genetics Society of Japan

雑誌

The Japanese journal of genetics (ISSN:0021504X)

巻号頁・発行日

vol.66, no.4, pp.513-525, 1991-08

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Induced somatic pink mutation frequencies in the stamen hairs of Tradescantia KU 20 clone, a blue/pink heterozygote highly mutable spontaneously at lower temperature, were studied after treating with relatively small doses of Co-60 gamma rays (39 to 551 mGy or 3.9 to 55.1 rad), and were compared with those of two stable clones (non-mutable spontaneously), BNL 02 and KU 9, which are also blue/pink heterozygotes. It was found that the gamma-ray-induced mutation frequency in KU 20 clone was comparable (18.8 pink mutant events per 10(4) hair-cell divisions per Gy) to those in BNL 02 (12.2 and 21.2) and KU 9 (17.4) clones, when the spontaneous mutation frequencies of KU 20 clone were relatively low (at most about 5.7 and 2.3 times of BNL 02 and KU 9 clones, respectively). However, when the spontaneous mutation frequecies of KU 20 clone were much higher (up to about 65 and 27 times of BNL 02 and KU 9 clones, respectively), induced mutation frequency was significantly higher in KU 20 clone (58.8 pink mutant events per 10(4) hair-cell divisions per Gy) than in BNL 02 and KU 9 clones. The extent of increase in the gamma-ray-induced mutation frequency in the latter case was nevertheless very much less than the increase in the spontaneous mutation frequency, suggesting different mechanisms of initiation and repair of radiation-induced and spontaneous mutations.

著者

市川 定夫

出版者

The Genetics Society of Japan

雑誌

JAPANESE JOURNAL OF GENETICS (ISSN:0021504X)

巻号頁・発行日

vol.66, no.4, pp.513-525, 1991

被引用文献数

19

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Induced somatic pink mutation frequencies in the stamen hairs of Tradescantia KU 20 clone, a blue/pink heterozygote highly mutable spontaneously at lower temperature, were studied after treating with relatively small doses of Co-60 gamma rays (39 to 551 mGy or 3.9 to 55.1 rad), and were compared with those of two stable clones (non-mutable spontaneously), BNL 02 and KU 9, which are also blue/pink heterozygotes. It was found that the gamma-ray-induced mutation frequency in KU 20 clone was comparable (18.8 pink mutant events per 10(4) hair-cell divisions per Gy) to those in BNL 02 (12.2 and 21.2) and KU 9 (17.4) clones, when the spontaneous mutation frequencies of KU 20 clone were relatively low (at most about 5.7 and 2.3 times of BNL 02 and KU 9 clones, respectively). However, when the spontaneous mutation frequecies of KU 20 clone were much higher (up to about 65 and 27 times of BNL 02 and KU 9 clones, respectively), induced mutation frequency was significantly higher in KU 20 clone (58.8 pink mutant events per 10(4) hair-cell divisions per Gy) than in BNL 02 and KU 9 clones. The extent of increase in the gamma-ray-induced mutation frequency in the latter case was nevertheless very much less than the increase in the spontaneous mutation frequency, suggesting different mechanisms of initiation and repair of radiation-induced and spontaneous mutations.

著者

小原 良孝

出版者

Genetics Society of Japan

巻号頁・発行日

vol.60, no.2, pp.157-160, 1985 (Released:2014-03-27)

著者

小原 良孝

出版者

Genetics Society of Japan

雑誌

The Japanese journal of genetics (ISSN:0021504X)

巻号頁・発行日

vol.60, no.2, pp.157-160, 1985-04

著者

塩田 義蔵

出版者

日本遺伝学会

雑誌

遺伝学雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.37, no.3, pp.248-252, 1962 (Released:2007-05-21)

参考文献数

4

被引用文献数

1

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1951年から1960年にわたる10年間, 異なった種類の組合せ(銀黒×銀黒, プラチナ×プラチナ,銀黒×プラチナ)についてそれぞれ10組の交配を行ない, その産児の litter size, 性比および毛色の分離を調査した。その結果は第1~4表と第1図に要約される。プラチナ形質は銀黒に対して優性でプラチナ遺伝子をホモにもつと致死作用を現わし, プラチナ狐はその遺伝子に関して常にヘテロの状熊にある。従ってプラチナ相互の交配による産児の表現は銀黒とプラチナに分離しその割合は 1:2となる。litter size は毛色の組合せによって異なり, 銀黒×プラチナでは銀黒相互交配の場合よりかなり小さく, むしろプラチナ相互交配の litter size に近い値を示した。このことより銀黒狐に対してプラチナ狐を配すると, より多くの虚弱胎児をもつことが想像され, それにはプラチナ親の生殖細胞かプラチナ遺伝子ヘテロの胎児に原因があるように思われる。産児の性比はいずれの場合も正常で, 銀黒およびプラチナ形質は常染色体性の遺伝をなすものと考えられる。

著者

近藤 宗平 野村 大成 梁 治子

出版者

日本遺伝学会

雑誌

遺伝学雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.57, no.3, pp.p321-336, 1982-06

著者

野口 彌吉 菅原 友太

出版者

日本遺伝学会

雑誌

遺伝學雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.18, no.2, pp.117-118, 1942

著者

野口 彌吉

出版者

日本遺伝学会

雑誌

遺伝學雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.19, no.3, pp.106-107, 1943

被引用文献数

1

著者

古川 貴久 小早川 義尚 田村 公実子 木村 賢一 川市 正史 谷村 禎一 本庶 佑

出版者

日本遺伝学会

雑誌

The Japanese journal of genetics (ISSN:0021504X)

巻号頁・発行日

vol.70, no.4, pp.505-524, 1995-08-25

参考文献数

63

被引用文献数

1

著者

Masa-Aki YAMADA Saburo NAWA Takao K. WATANABE

出版者

The Genetics Society of Japan

雑誌

遺伝学雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.57, no.3, pp.301-305, 1982 (Released:2006-07-25)

参考文献数

5

被引用文献数

12 17

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A mutant of a strain of the SR organisms (SRO, transovarially transmitted male-killing spiroplasmas) of Drosophila is described. The mutant, NSRO-A, has lost the male-specific killing activity on host flies, but maintains other properties such as the clump forming spectrum and the extractable titer of the associated virus as original NSRO strain.

著者

菊池 秋雄

出版者

日本遺伝学会

雑誌

遺伝學雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.3, no.1, pp.1-21, 1924

被引用文献数

11

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I. ON THE RELATION BETWEEN CULTIVATED VARIETIES AND WILD SPECIES IN THE GENUS <i>Pyrus</i> OF THE ORIENT.

著者

市川 定夫 山口 明彦 奥村 幹子

出版者

Genetics Society of Japan

雑誌

The Japanese journal of genetics (ISSN:0021504X)

巻号頁・発行日

vol.68, no.4, pp.277-292, 1993-08-25

参考文献数

25

被引用文献数

11 23

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Young inflorescences of <i>Tradescantia</i> clones KU 27 and BNL 4430, the both of which are blue/pink heterozygotes and have been demonstrated to be highly sensitive to alkylating agents, were exposed either to aqueous solutions of methyl methanesulfonate (MMS) for 16hr alone (at 0.005 to 0.02% for KU 27 and at 0.005% for BNL 4430) or to acute 150 kVp X rays alone (161 to 531 mGy for KU 27 and 501 to 976 mGy for BNL 4430), or in combinations (134 to 448 mGy for KU 27 and 458 to 865mGy for BNL 4430 after the 0.005% MMS treatment). The induced somatic pink mutation frequencies per hair-cell division were studied and compared, and clone BNL 4430 was found to be nearly two times more sensitive to MMS than clone KU 27, while the X-ray-induced mutation frequencies in the latter was about 1.5 times higher than those in the former. The lower sensitivity to MMS of clone KU 27 (as compared with BNL 4430) was nevertheless about 5.6 times higher as compared with the responses of clone BNL 02 to MMS reported earlier, proving the high sensitivities of the two clones used in the present study. Clear synergistic effects of MMS and X rays were observed in the both clones, indicating that the mechanisms of inducing mutations are common at least in part between MMS and X rays.<br>

著者

Akihiko INABA

出版者

The Genetics Society of Japan

雑誌

遺伝学雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.34, no.5, pp.137-139, 1959 (Released:2007-05-21)

参考文献数

3

被引用文献数

4 6

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The chromosomes of two octopods, Octopus vulgaris (Lamarck) and O. variabilis Sasaki, were observed in male germ-cells. The chromosome number was found to be 28 (n) in both species. Morphologically there is a genearal similarity between the two in respect to the chromosomes. There is no evidence for the presence of a sex chromosome in the male.

著者

市川 定夫

出版者

The Genetics Society of Japan

雑誌

JAPANESE JOURNAL OF GENETICS (ISSN:0021504X)

巻号頁・発行日

vol.56, no.4, pp.409-423, 1981

被引用文献数

18

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Two triploid clones (KU 7 and KU 9) of Tradescantia heterozygous for flower color were exposed to 1 to 42.3R of gamma rays or the scattering radiation in the gamma field of the Institute of Radiation . Breeding. Occurrence of somatic pink mutations in the stamen hairs was investigated 10 to 16 (or 14) days after irradiation. The mutation frequency was found to increase linearly with increasing gamma-ray exposure in the both clones, and the frequencies of 0.437 and 0.468 pink mutant events per 103 hairs per R were determined for KU 7 and KU 9, respectively. When the data collected in the present study were analyzed together with those obtained in earlier experiments in the gamma field, linear relationships of the somatic mutation frequency with gamma-ray (2.1 to 201.6R) and scattering radiation (0.72 to 57.6R) exposures were confirmed. Scattering radiation was found to have a genetical efficiency more than two times higher than that of gamma rays. Variation of spontaneous mutation frequency observed in the present study and in earlier studies was inversely correlated to temperature variation.

著者

森脇 大五郎

出版者

日本遺伝学会

雑誌

遺伝学雑誌 (ISSN:0021504X)

巻号頁・発行日

vol.10, no.3-4, pp.250-254, 1934 (Released:2007-11-30)

参考文献数

14