{"title":"Evolution of mitochondrial DNA in Paramecium caudatum","authors":"Y. Tsukii","doi":"10.1266/JJG.69.307","DOIUrl":"https://doi.org/10.1266/JJG.69.307","url":null,"abstract":"","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"55 1","pages":"307-319"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73600593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dynamic changes in the morphology of barley chromosomes during the mitotic metaphase stage were observed and attributed to the differential condensation of the chromosome arms. The mitotic stage of the 250 metaphase spreads was classified into five sub-stages from early metaphase to late metaphase. At each sub-stage, the relative length (RL) and the arm ratio (AR) of the chromosomes were examined and the ranking of the chromosomes for the two parameters was also determined for the respective chromosomal spreads. As a result, the RL and AR values of some of the chromosomes as well as their ranking for the two parameters were found to vary with the progression of the metaphase stage. The dynamic changes in the RL and AR values were closely related to the differences in the condensation rate of the chromosome arm. Factors involved in the differential chromosome condensation are discussed.
{"title":"Dynamic changes in the morphology of barley chromosomes during the mitotic metaphase stage","authors":"K. Kakeda, K. Fukui","doi":"10.1266/JJG.69.545","DOIUrl":"https://doi.org/10.1266/JJG.69.545","url":null,"abstract":"Dynamic changes in the morphology of barley chromosomes during the mitotic metaphase stage were observed and attributed to the differential condensation of the chromosome arms. The mitotic stage of the 250 metaphase spreads was classified into five sub-stages from early metaphase to late metaphase. At each sub-stage, the relative length (RL) and the arm ratio (AR) of the chromosomes were examined and the ranking of the chromosomes for the two parameters was also determined for the respective chromosomal spreads. As a result, the RL and AR values of some of the chromosomes as well as their ranking for the two parameters were found to vary with the progression of the metaphase stage. The dynamic changes in the RL and AR values were closely related to the differences in the condensation rate of the chromosome arm. Factors involved in the differential chromosome condensation are discussed.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"496 1","pages":"545-554"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78841863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The nearly neutral theory proposes that interaction of selection and drift is important in molecular evolution. The theory predicts that evolutionary rate is negatively correlated with the species population size, for those genes whose function has been fixed long time ago. The prediction is tested through analysis of sequence data of 17 mammalian genes by estimating divergence among genes separately for synonymous substitutions and nonsynonymous substitutions. Star phylogenies composed of rodentia, artiodactyla and primates are examined. The generation-time effect is found to be more conspicuous for synonymous substitutions than for nonsynonymous substitutions. This result supports the nearly neutral theory.
{"title":"Interaction of selection and drift in molecular evolution","authors":"T. Ohta","doi":"10.1266/JJG.68.529","DOIUrl":"https://doi.org/10.1266/JJG.68.529","url":null,"abstract":"The nearly neutral theory proposes that interaction of selection and drift is important in molecular evolution. The theory predicts that evolutionary rate is negatively correlated with the species population size, for those genes whose function has been fixed long time ago. The prediction is tested through analysis of sequence data of 17 mammalian genes by estimating divergence among genes separately for synonymous substitutions and nonsynonymous substitutions. Star phylogenies composed of rodentia, artiodactyla and primates are examined. The generation-time effect is found to be more conspicuous for synonymous substitutions than for nonsynonymous substitutions. This result supports the nearly neutral theory.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"5 1","pages":"529-537"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79467430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Retrospective of the last quarter century of the neutral theory","authors":"Motoo KlMURA","doi":"10.1266/JJG.68.521","DOIUrl":"https://doi.org/10.1266/JJG.68.521","url":null,"abstract":"","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"45 1","pages":"521-528"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86913584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
By adding data on allozyme variability in 35 populations from southern and central China, I completed a worldwide survey of allozyme variability in common buckwheat. The following remarks were born out from the survey. (1) At all loci, allele frequency does not vary so much among the populations from a wide range of Asian countries. (2) Most of the evolutionary events which might occur during the spread of buckwheat cultivation are the losses of variant alleles by random drift. (3) Drastic changes of gene frequency have been observed only in marginal populations, in Kumaun, Garwhal hills and Kashmir in India and in southern Europe. (4) Cultivated buckwheat has more genetic variability than the natural populations of the wild ancestor. Large population size and complete panmixis of a population and enough migration between populations may be responsible for observation (1) and may also have led to the accumulation of variant alleles in cultivated populations, i.e. observation (4). Random drift, such as founder effect, took place only in marginal populations, accounting for observations (2) and (3). Buckwheat provides an example that contradicts Vavilov's assertion; it says that the center of genetic diversity of a cultivated plant is the place of its origin. Buckwheat is apparently monocentric, but the pattern of variation suggests domestication over a wide area, instead of progressive decline in diversity from the center of origin to the periphery. The structure of buckwheat populations and their mating system are mainly responsible for this unexpected result.
{"title":"Population genetics of cultivated common buckwheat, Fagopyrum esculentum Moench. IX. Concluding remarks on worldwide survey of allozyme variability","authors":"O. Ohnishi","doi":"10.1266/JJG.68.317","DOIUrl":"https://doi.org/10.1266/JJG.68.317","url":null,"abstract":"By adding data on allozyme variability in 35 populations from southern and central China, I completed a worldwide survey of allozyme variability in common buckwheat. The following remarks were born out from the survey. (1) At all loci, allele frequency does not vary so much among the populations from a wide range of Asian countries. (2) Most of the evolutionary events which might occur during the spread of buckwheat cultivation are the losses of variant alleles by random drift. (3) Drastic changes of gene frequency have been observed only in marginal populations, in Kumaun, Garwhal hills and Kashmir in India and in southern Europe. (4) Cultivated buckwheat has more genetic variability than the natural populations of the wild ancestor. Large population size and complete panmixis of a population and enough migration between populations may be responsible for observation (1) and may also have led to the accumulation of variant alleles in cultivated populations, i.e. observation (4). Random drift, such as founder effect, took place only in marginal populations, accounting for observations (2) and (3). Buckwheat provides an example that contradicts Vavilov's assertion; it says that the center of genetic diversity of a cultivated plant is the place of its origin. Buckwheat is apparently monocentric, but the pattern of variation suggests domestication over a wide area, instead of progressive decline in diversity from the center of origin to the periphery. The structure of buckwheat populations and their mating system are mainly responsible for this unexpected result.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"6 1","pages":"317-326"},"PeriodicalIF":0.0,"publicationDate":"1993-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82422922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cloned sequences of three retrotransposons of rice, Tos1-1, Tos2-1 and Tos3-1, were used as molecular genetic markers to distinguish the cultivars of Asian and African rice, Oryza sativa and Oryza glaberrima. DNAs of six cultivars each of Indica and Japonica types of O. sativa were analyzed after digestion with four different restriction enzymes. Indica cultivars could be distinguished from each other by any of three types of one probe-one restriction enzyme combination. Although the hybridization patterns were similar among Japonica cultivars, these cultivars could be distinguished from each other by one type of one probe-one enzyme combination. Five cultivars of O. glaberrima examined were also distinguished from each other by using one probe-one enzyme combination. The results shown here indicate that retrotransposon-mediated fingerprinting is an efficient method to distinguish or identify the cultivars of rice. Retrotransposonmediated fingerprinting should become a general method, because retrotransposons are ubiquitous in plant species and retrotransposon probes can easily be obtained from any plant species.
{"title":"DNA fingerprinting of cultivated rice with rice retrotransposon probes","authors":"Atushi Fukuchi, F. Kikuchi, H. Hirochika","doi":"10.1266/JJG.68.195","DOIUrl":"https://doi.org/10.1266/JJG.68.195","url":null,"abstract":"Cloned sequences of three retrotransposons of rice, Tos1-1, Tos2-1 and Tos3-1, were used as molecular genetic markers to distinguish the cultivars of Asian and African rice, Oryza sativa and Oryza glaberrima. DNAs of six cultivars each of Indica and Japonica types of O. sativa were analyzed after digestion with four different restriction enzymes. Indica cultivars could be distinguished from each other by any of three types of one probe-one restriction enzyme combination. Although the hybridization patterns were similar among Japonica cultivars, these cultivars could be distinguished from each other by one type of one probe-one enzyme combination. Five cultivars of O. glaberrima examined were also distinguished from each other by using one probe-one enzyme combination. The results shown here indicate that retrotransposon-mediated fingerprinting is an efficient method to distinguish or identify the cultivars of rice. Retrotransposonmediated fingerprinting should become a general method, because retrotransposons are ubiquitous in plant species and retrotransposon probes can easily be obtained from any plant species.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"14 1","pages":"195-204"},"PeriodicalIF":0.0,"publicationDate":"1993-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78624050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An indirect immunofluorescence method detecting the incorporation of BrdU was applied to analyze the DNA replication pattern in soybean chromosomes which are very small among plant species so far examined. Discrete fluorescent images in the distal, interstitial and proximal regions of the chromosome arms were revealed at prometaphase. Time-course analysis indicated that the DNA replication starts at the distal region. The replication patterns are discussed in relation to other chromosomal characteristics such as the location of constitutive heterochromatin and the stainability with the Giemsa.
{"title":"Analysis of replication pattern in soybean chromosomes by indirect immunofluorescence method","authors":"T. Yanagisawa, S. Tano, K. Fukui, K. Harada","doi":"10.1266/JJG.68.119","DOIUrl":"https://doi.org/10.1266/JJG.68.119","url":null,"abstract":"An indirect immunofluorescence method detecting the incorporation of BrdU was applied to analyze the DNA replication pattern in soybean chromosomes which are very small among plant species so far examined. Discrete fluorescent images in the distal, interstitial and proximal regions of the chromosome arms were revealed at prometaphase. Time-course analysis indicated that the DNA replication starts at the distal region. The replication patterns are discussed in relation to other chromosomal characteristics such as the location of constitutive heterochromatin and the stainability with the Giemsa.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"310 1","pages":"119-125"},"PeriodicalIF":0.0,"publicationDate":"1993-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76453815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To obtain new information on the phylogenetic relationships between wild and cultivated einkorn wheats and their relation to polyploid wheats, we made restriction fragment length polymorphism (RFLP) analyses of the nuclear DNAs of diploid and polyploid wheats. Two to three accessions of three einkorn species, Triticum boeoticum and T. urartu (both wild), and T. monococcum (cultivated), and a single accession each of emmer and common wheats were used. Forty-six DNA clones known to hybridize the DNA of the A genome chromosomes were selected from the genomic library of common wheat and used as probes in Southern hybridization of the total DNAs of all above accessions which were digested with BamHI or HindIII. Genetic distances were calculated between all the pairs of accessions from RFLP data obtained from 88 probe-enzyme combinations, clustering being obtained by the UPGMA method. All the accessions of T. urartu, T. durum and T. aestivum were clustered in one group. Those of T. boeoticum and T. monococcum were in a different group. We conclude that T. monococcum is derived from T. boeoticum and that the A genomes of the emmer and common wheats originated in T. urartu.
{"title":"Wheat phytogeny determined by RFLP analysis of nuclear DNA. 1. Einkorn wheat","authors":"S. Takumi, S. Nasuda, Yaoguang Liu, K. Tsunewaki","doi":"10.1266/JJG.68.73","DOIUrl":"https://doi.org/10.1266/JJG.68.73","url":null,"abstract":"To obtain new information on the phylogenetic relationships between wild and cultivated einkorn wheats and their relation to polyploid wheats, we made restriction fragment length polymorphism (RFLP) analyses of the nuclear DNAs of diploid and polyploid wheats. Two to three accessions of three einkorn species, Triticum boeoticum and T. urartu (both wild), and T. monococcum (cultivated), and a single accession each of emmer and common wheats were used. Forty-six DNA clones known to hybridize the DNA of the A genome chromosomes were selected from the genomic library of common wheat and used as probes in Southern hybridization of the total DNAs of all above accessions which were digested with BamHI or HindIII. Genetic distances were calculated between all the pairs of accessions from RFLP data obtained from 88 probe-enzyme combinations, clustering being obtained by the UPGMA method. All the accessions of T. urartu, T. durum and T. aestivum were clustered in one group. Those of T. boeoticum and T. monococcum were in a different group. We conclude that T. monococcum is derived from T. boeoticum and that the A genomes of the emmer and common wheats originated in T. urartu.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"46 1","pages":"73-79"},"PeriodicalIF":0.0,"publicationDate":"1993-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74334983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nei's (1972) genetic distance were estimated among 21 populations of the common freshwater shrimp Paratya compressa improvisa, living in the northern part of Japan. The estimates were based on examination of 18 enzyme loci by starch-gel electrophoresis. These shrimp populations were genetically classified into three geographic groups on the basis of predominating alleles typical for two loci Fdp-1 and Fdp-2. The "Kanto group" consisted of individuals having Fdp-1a and Fdp-2c, the "Japan Sea group" having Fdp-1b and Fdp-2a, and the "Pacific Ocean group" having Fdp-1b and Fdp-2c. Nei's genetic distance among the three different geographic groups, varied from 0.0572 to 0.2136. Average genetic distances were 0.1001 between Pacific Ocean and Japan Sea groups, 0.0851 between Pacific Ocean and Kanto groups, and 0.1990 between Japan Sea and Kanto groups. These values of genetic distance among the three groups are comparable with those among different subspecies.
{"title":"Genetic differentiation among local populations of common freshwater shrimp Paratya compressa improvisa","authors":"M. Ikeda, A. Kijima, Y. Fujio","doi":"10.1266/JJG.68.293","DOIUrl":"https://doi.org/10.1266/JJG.68.293","url":null,"abstract":"Nei's (1972) genetic distance were estimated among 21 populations of the common freshwater shrimp Paratya compressa improvisa, living in the northern part of Japan. The estimates were based on examination of 18 enzyme loci by starch-gel electrophoresis. These shrimp populations were genetically classified into three geographic groups on the basis of predominating alleles typical for two loci Fdp-1 and Fdp-2. The \"Kanto group\" consisted of individuals having Fdp-1a and Fdp-2c, the \"Japan Sea group\" having Fdp-1b and Fdp-2a, and the \"Pacific Ocean group\" having Fdp-1b and Fdp-2c. Nei's genetic distance among the three different geographic groups, varied from 0.0572 to 0.2136. Average genetic distances were 0.1001 between Pacific Ocean and Japan Sea groups, 0.0851 between Pacific Ocean and Kanto groups, and 0.1990 between Japan Sea and Kanto groups. These values of genetic distance among the three groups are comparable with those among different subspecies.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"18 1","pages":"293-302"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90580225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The genes responsible for three types of chlorosis found in hybrids between the Emmer and the Timopheevi group of tetraploid wheats were analyzed by test crosses. The presence of the complementary genes, Cs1 and cs1 in the Emmer group and Cs2s, Cs2m, Cs2w and cs2 in the Timopheevi group were confirmed. The frequency of Cs1 in the Emmer group was very low and none of the wild Triticum dicoccoides strains had Cs1. On the other hand, about half of the strains of the wild Timopheevi, T. araraticum, and all strains of the cultivated T. timopheevi had either Cs2s, Cs2m or Cs2w.
{"title":"Genetic analysis of Cs chlorosis in tetraploid wheats","authors":"T. Kawahara","doi":"10.1266/JJG.68.147","DOIUrl":"https://doi.org/10.1266/JJG.68.147","url":null,"abstract":"The genes responsible for three types of chlorosis found in hybrids between the Emmer and the Timopheevi group of tetraploid wheats were analyzed by test crosses. The presence of the complementary genes, Cs1 and cs1 in the Emmer group and Cs2s, Cs2m, Cs2w and cs2 in the Timopheevi group were confirmed. The frequency of Cs1 in the Emmer group was very low and none of the wild Triticum dicoccoides strains had Cs1. On the other hand, about half of the strains of the wild Timopheevi, T. araraticum, and all strains of the cultivated T. timopheevi had either Cs2s, Cs2m or Cs2w.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"84 1","pages":"147-153"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77497696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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