Selected stable standard Solanum genotypes and two populations of asymmetric somatic hybrids between Solanum brevidens (2n=2x=24) and dihaploid S. tuberosum (2n=2x=24) were analyzed to test the resolution of flow cytometric determination of nuclear DNA content (2C value) in terms of a loss or gain of chromosomes, and to analyze the correlation between the 2C value and the chromosome number. Correlation was high within the standard genotypes (r=0.99, P<0.001). However, the correlation was low within the two populations of somatic hybrids (r=0.54 and 0.65, 0.01
{"title":"Analysis of correlation between nuclear DNA content, chromosome number, and flowering capacity of asymmetric somatic hybrids of diploid Solanum brevidens and (di) haploid S. tuberosum","authors":"J. Valkonen, K. Watanabe, E. Pehu","doi":"10.1266/JJG.69.525","DOIUrl":"https://doi.org/10.1266/JJG.69.525","url":null,"abstract":"Selected stable standard Solanum genotypes and two populations of asymmetric somatic hybrids between Solanum brevidens (2n=2x=24) and dihaploid S. tuberosum (2n=2x=24) were analyzed to test the resolution of flow cytometric determination of nuclear DNA content (2C value) in terms of a loss or gain of chromosomes, and to analyze the correlation between the 2C value and the chromosome number. Correlation was high within the standard genotypes (r=0.99, P<0.001). However, the correlation was low within the two populations of somatic hybrids (r=0.54 and 0.65, 0.01<P<0.05). Highly chimeric , hybrids were readily detected by flow cytometry, whereas microscopic chromosome observations failed to detect them. Data were analyzed regarding their potential usefulness in predicting the flowering capacity. The 2C values deviating from those of the euploid standard genotypes were highly associated with abnormal morphology and lack of flowering. Flowering capacity did not correlate with chromosome number. These results suggest that flow cytometry can be utilized for initial selection of somatic hybrids.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"124 1","pages":"525-536"},"PeriodicalIF":0.0,"publicationDate":"1994-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87888121","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 chromosomal locations of glutamate oxaloacetate transaminase gene loci in Japanese bunching onion (Allium fistulosum L., 2n=2X= 16, FF) and shallot (A. cepa L. Aggregatum group, 2n=2X = l6, AA) were investigated using alien monosomic addition lines (2n=2X+1=17, FF+nA, AA+nF) and hypoallotriploid lines (2n=3X-1=23, AFF-nA, AAF-nF) between these two species. The gene locus Got-2 was located on the homoeologous sub-telocentric chromosomes, 6F in A. fistulosum and 6A in A. cepa Aggregatum group. The gene locus Got-1 was on the other chromosomes. The present results indicate that chromosomal locations of these gene loci, at least Got-2, were conservative both in A. fistulosum and A. cepa Aggregatum group during speciation and subsequent evolution.
{"title":"Chromosomal locations of glutamate oxaloacetate transaminase gene loci in Japanese bunching onion (Allium fistulosum L.) and shallot (A. cepa L. Aggregatum group)","authors":"M. Shigyo, Y. Tashiro, S. Miyazaki","doi":"10.1266/JJG.69.417","DOIUrl":"https://doi.org/10.1266/JJG.69.417","url":null,"abstract":"The chromosomal locations of glutamate oxaloacetate transaminase gene loci in Japanese bunching onion (Allium fistulosum L., 2n=2X= 16, FF) and shallot (A. cepa L. Aggregatum group, 2n=2X = l6, AA) were investigated using alien monosomic addition lines (2n=2X+1=17, FF+nA, AA+nF) and hypoallotriploid lines (2n=3X-1=23, AFF-nA, AAF-nF) between these two species. The gene locus Got-2 was located on the homoeologous sub-telocentric chromosomes, 6F in A. fistulosum and 6A in A. cepa Aggregatum group. The gene locus Got-1 was on the other chromosomes. The present results indicate that chromosomal locations of these gene loci, at least Got-2, were conservative both in A. fistulosum and A. cepa Aggregatum group during speciation and subsequent evolution.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"26 1","pages":"417-424"},"PeriodicalIF":0.0,"publicationDate":"1994-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87296138","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}
Seventy five rice genomic clones were hybridized to eight cereal genomes, i.e., rice, maize, barley, rye, Einkorn wheat, Emmer Wheat, and two common wheats to characterize the genome features of cereals. The sequence of 75% (56 clones) of these clones were commonly detected in the eight cereal DNAs, indicating that the cereal genomes contain those sequences homologous to probe DNAs. Sixteen percent (12 clones) revealed positive signals only in the rice DNA, harboring rice-specific sequences. Only 9 clones (12%) gave discrete bands in wheat DNAs, showing them to be possible candidates for probes for construction of a wheat RFLP map. Approximately, one-third of the clones (26/75) were transcribed in the green leaves of cereals. Although these genomic clones were originally selected as low-copy clones, a quarter of them (18 clones) were multiplied in the rice geome, but not repetitively, and were thus defined as multiplecopy clones. The remaining 76% of clones were classified as single-copy ones. The genome regions around multiple-copy clones had tendency to be more conservatively retained among the cereal genomes, and showed more frequent transcription activity than single-copy regions. The distributions of these characterized clones were traced in the rice RFLP map. While rice-specific sequences were dispersed throughout the chromosomes, those commonly detected among the cereal genomes had a tendency to occur in clusters.
{"title":"Toward construction of synteny maps among cereal genomes. I. Molecular characterization of cereal genomes as probed by rice genomic clones","authors":"Y. Ogihara, K. Isono, A. Saito","doi":"10.1266/JJG.69.347","DOIUrl":"https://doi.org/10.1266/JJG.69.347","url":null,"abstract":"Seventy five rice genomic clones were hybridized to eight cereal genomes, i.e., rice, maize, barley, rye, Einkorn wheat, Emmer Wheat, and two common wheats to characterize the genome features of cereals. The sequence of 75% (56 clones) of these clones were commonly detected in the eight cereal DNAs, indicating that the cereal genomes contain those sequences homologous to probe DNAs. Sixteen percent (12 clones) revealed positive signals only in the rice DNA, harboring rice-specific sequences. Only 9 clones (12%) gave discrete bands in wheat DNAs, showing them to be possible candidates for probes for construction of a wheat RFLP map. Approximately, one-third of the clones (26/75) were transcribed in the green leaves of cereals. Although these genomic clones were originally selected as low-copy clones, a quarter of them (18 clones) were multiplied in the rice geome, but not repetitively, and were thus defined as multiplecopy clones. The remaining 76% of clones were classified as single-copy ones. The genome regions around multiple-copy clones had tendency to be more conservatively retained among the cereal genomes, and showed more frequent transcription activity than single-copy regions. The distributions of these characterized clones were traced in the rice RFLP map. While rice-specific sequences were dispersed throughout the chromosomes, those commonly detected among the cereal genomes had a tendency to occur in clusters.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"42 1","pages":"347-360"},"PeriodicalIF":0.0,"publicationDate":"1994-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84418508","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}
Transformation of ciliates was attempted with a circular plasmid containing a chromosomal DNA of the hypotrichous ciliate Stylonychia lemnae by calcium phosphate-mediated transfection. The plasmid, designated Tubingen-3, was constructed from a bacterial plasmid, a gene for neomycin resistance derived from a vector for the cellular slime mold Dictyostelium, and a 1.2 kb macronuclear chromosomal DNA of Stylonychia. Transformants were obtained at a frequency of one per 104 to 105 of input cells in Stylonychia lemnae and at a lower frequency, one per 10 6, in Tetrahymena thermophila. The vector when simply linearized by digestion with restriction enzymes failed to give transformants, whereas when the vector was linearized so as to have short telomeric sequences at both ends, effective transformation was again observed. The Dictyostelium vector, pCERF DRpl4, with a segment of DNA that contained the putative origin of replication was found, unexpectedly, to be effective in transforming Stylonychia cells. The origin of replication in Stylonychia and Dictyostelium might thus be functionally similar.
{"title":"Transformation of ciliates with a circular plasmid derived from an overamplified macronuclear DNA of Stylonychia lemnae","authors":"H. Endoh","doi":"10.1266/JJG.69.377","DOIUrl":"https://doi.org/10.1266/JJG.69.377","url":null,"abstract":"Transformation of ciliates was attempted with a circular plasmid containing a chromosomal DNA of the hypotrichous ciliate Stylonychia lemnae by calcium phosphate-mediated transfection. The plasmid, designated Tubingen-3, was constructed from a bacterial plasmid, a gene for neomycin resistance derived from a vector for the cellular slime mold Dictyostelium, and a 1.2 kb macronuclear chromosomal DNA of Stylonychia. Transformants were obtained at a frequency of one per 104 to 105 of input cells in Stylonychia lemnae and at a lower frequency, one per 10 6, in Tetrahymena thermophila. The vector when simply linearized by digestion with restriction enzymes failed to give transformants, whereas when the vector was linearized so as to have short telomeric sequences at both ends, effective transformation was again observed. The Dictyostelium vector, pCERF DRpl4, with a segment of DNA that contained the putative origin of replication was found, unexpectedly, to be effective in transforming Stylonychia cells. The origin of replication in Stylonychia and Dictyostelium might thus be functionally similar.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"19 1","pages":"377-383"},"PeriodicalIF":0.0,"publicationDate":"1994-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86899099","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}
Triticum aestivum cv. Norin 26 with Aegilops crassa cytoplasm shows photo-period-sensitive cytoplasmic male sterility (PCMS). This alloplasmic line is almost completely male sterile under a long-day condition (15 h light period), but highly male fertile under a short-day condition (14.5 h light period). The alloplasmic line of T. aestivum cv. Chinese Spring with the same cytoplasm does not express PCMS. Conventional and telosomic analyses revealed that the fertility restoration manifested by Chinese Spring is controlled mainly by a single dominant gene (designated Rfd1) located on the long arm of chromosome 7B, and that a large number of modifiers are involved in modifying the level of fertility restoration. The function of the Rfd1 gene is expressed sporophytically. A slight certation was observed between the two types of pollen grains, one carrying and the other not carrying this gene, under the presence of Ae. crassa cytoplasm.
{"title":"Genetic analysis on the fertility restoration by Triticum aestivum cv. Chinese Spring against photoperiod-sensitive cytoplasmic male sterility","authors":"K. Murai, K. Tsunewaki","doi":"10.1266/JJG.69.195","DOIUrl":"https://doi.org/10.1266/JJG.69.195","url":null,"abstract":"Triticum aestivum cv. Norin 26 with Aegilops crassa cytoplasm shows photo-period-sensitive cytoplasmic male sterility (PCMS). This alloplasmic line is almost completely male sterile under a long-day condition (15 h light period), but highly male fertile under a short-day condition (14.5 h light period). The alloplasmic line of T. aestivum cv. Chinese Spring with the same cytoplasm does not express PCMS. Conventional and telosomic analyses revealed that the fertility restoration manifested by Chinese Spring is controlled mainly by a single dominant gene (designated Rfd1) located on the long arm of chromosome 7B, and that a large number of modifiers are involved in modifying the level of fertility restoration. The function of the Rfd1 gene is expressed sporophytically. A slight certation was observed between the two types of pollen grains, one carrying and the other not carrying this gene, under the presence of Ae. crassa cytoplasm.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"9 1","pages":"195-202"},"PeriodicalIF":0.0,"publicationDate":"1994-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90169803","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}
Chromosome evolution in primitive Australian ants of the Myrmecia pilosula species complex is investigated in the context of the minimum interaction theory. Under the minimum interaction theory, selection favors rearrangements tending to reduce the occurrence of deleterious chromosomal mutations, and hence chromosome numbers are expected to increase. The complex is chromosomally highly heterogeneous (2n = 2-32), and comprises at least 5 karyotypically distinct species: M. croslandi (2n=2-4), M. imaii (2n=6-8), M. banksi (2n=9-10), M. haskinsorum (2n=12-24), and M. pilosula (2n=18-32). Statistical considerations using the karyograph method and chromosomal alteration network analysis indicate that chromosome evolution of the complex proceeds as a whole towards increase in chromosome number by centric fission and, inversions converting chromosomes from aero- to metacentrics (A-M-inversion). These conclusions are consistent with the predictions of the minimum interaction theory. Both centric fusion and A-M-inversion serve to eliminate constitutive heterochromatin (visible as C-bands), which appears to increase in a saltatory fashion after centric fission, probably due to telomere instability. Newly observed phenomena which we term "fusion burst" and "fission burst" suggest that rates of chromosome evolution in M. pilosula have fluctuated with time.
{"title":"Experimental bases for the minimum interaction theory. I. Chromosome evolution in ants of the Myrmecia pilosula species complex (Hymenoptera: Formicidae: Myrmeciinae)","authors":"H. Imai, Robert W. Taylor, R. Crozier","doi":"10.1266/JJG.69.137","DOIUrl":"https://doi.org/10.1266/JJG.69.137","url":null,"abstract":"Chromosome evolution in primitive Australian ants of the Myrmecia pilosula species complex is investigated in the context of the minimum interaction theory. Under the minimum interaction theory, selection favors rearrangements tending to reduce the occurrence of deleterious chromosomal mutations, and hence chromosome numbers are expected to increase. The complex is chromosomally highly heterogeneous (2n = 2-32), and comprises at least 5 karyotypically distinct species: M. croslandi (2n=2-4), M. imaii (2n=6-8), M. banksi (2n=9-10), M. haskinsorum (2n=12-24), and M. pilosula (2n=18-32). Statistical considerations using the karyograph method and chromosomal alteration network analysis indicate that chromosome evolution of the complex proceeds as a whole towards increase in chromosome number by centric fission and, inversions converting chromosomes from aero- to metacentrics (A-M-inversion). These conclusions are consistent with the predictions of the minimum interaction theory. Both centric fusion and A-M-inversion serve to eliminate constitutive heterochromatin (visible as C-bands), which appears to increase in a saltatory fashion after centric fission, probably due to telomere instability. Newly observed phenomena which we term \"fusion burst\" and \"fission burst\" suggest that rates of chromosome evolution in M. pilosula have fluctuated with time.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"4 1","pages":"137-182"},"PeriodicalIF":0.0,"publicationDate":"1994-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77994495","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}
RFLP mapping of a cloned peroxidase gene from rice was performed using a F2 population derived from a crossing of an indica ('Kasalath') × a japonica ('FL134'). The peroxidase gene was mapped between two RFLP markers (XNpb373 and XNpb244-2) in the relatively distal region opposite to chl-1 on chromosome 3. It is concluded that this locus of the peroxidase gene is different from the loci determined by isozyme analyses.
{"title":"RFLP mapping of a coding sequence for rice peroxidase: detection of a locus different from those determined by isozyme analyses","authors":"N. Kishimoto, Hiroyuki Ito, Y. Ohashi, A. Saito","doi":"10.1266/JJG.69.101","DOIUrl":"https://doi.org/10.1266/JJG.69.101","url":null,"abstract":"RFLP mapping of a cloned peroxidase gene from rice was performed using a F2 population derived from a crossing of an indica ('Kasalath') × a japonica ('FL134'). The peroxidase gene was mapped between two RFLP markers (XNpb373 and XNpb244-2) in the relatively distal region opposite to chl-1 on chromosome 3. It is concluded that this locus of the peroxidase gene is different from the loci determined by isozyme analyses.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"57 1","pages":"101-104"},"PeriodicalIF":0.0,"publicationDate":"1994-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76671692","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}
Reproducible random amplified polymorphic DNA (RAPD) patterns were obtained in two potato species (Solanum chacoense and S. phureja), one of their F1's, and its derived F2 population, by adjusting temperature profiles of the amplification process and template DNA concentrations (1 ng/μl reaction vol.). Although the number of amplified products and detectable differences between the two species increased with increasing GC content of the primer, 50% or 60% GC is recommended for maximizing scorable RAPDs in the F2 population. Using 82 primers, 589 RAPDs were detected between the parents, and 70% of them (409 RAPDs) in the F1 clone. The number of RAPDs reliably scored for their segregations in the F2 population was significantly lowered because of complicated RAPD patterns. Consequently, 22% of the RAPDs detected in the parents (129 RAPDs), an average of 1.57 RAPDs per primer, were obtained as genetic markers, which can be used for the construction of a genetic map for this particular population.
{"title":"Random amplified polymorphic DNA markers detected in a segregating hybrid population of Solanum chacoense × S. phureja","authors":"K. Hosaka, R. Hanneman","doi":"10.1266/JJG.69.53","DOIUrl":"https://doi.org/10.1266/JJG.69.53","url":null,"abstract":"Reproducible random amplified polymorphic DNA (RAPD) patterns were obtained in two potato species (Solanum chacoense and S. phureja), one of their F1's, and its derived F2 population, by adjusting temperature profiles of the amplification process and template DNA concentrations (1 ng/μl reaction vol.). Although the number of amplified products and detectable differences between the two species increased with increasing GC content of the primer, 50% or 60% GC is recommended for maximizing scorable RAPDs in the F2 population. Using 82 primers, 589 RAPDs were detected between the parents, and 70% of them (409 RAPDs) in the F1 clone. The number of RAPDs reliably scored for their segregations in the F2 population was significantly lowered because of complicated RAPD patterns. Consequently, 22% of the RAPDs detected in the parents (129 RAPDs), an average of 1.57 RAPDs per primer, were obtained as genetic markers, which can be used for the construction of a genetic map for this particular population.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"158 1","pages":"53-66"},"PeriodicalIF":0.0,"publicationDate":"1994-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80141737","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}
A critical evaluation of the digital data of 250 barley metaphase spreads obtained by image analysis revealed the instability of the chromosomal morphology during the mitotic metaphase stage. Both the relative length (RL) and arm ratio (AR) of the chromosomes, which are the two major numerical parameters in karyotype analysis, varied in the different chromosomal spreads. The ranking of the chromosomes for the respective parameters within a complement changed accordingly. The data indicated that karyotype analysis based merely on the numerical parameters RL and AR may lead to the misidentification of chromosomes, causing a misinterpretation of the data from different chromosomes when averaging several data. Thus, most of data of the RL and AR which have so far been reported may need reexamination except for the cases where chromosomes were identified based oh other critical parameters, e.g., banding pattern, condensation pattern, in situ hybridization, etc. Differential condensation between the chromosome arms may be the cause of the instability of the karyotype.
{"title":"A critical assessment of karyotype analysis by imaging methods","authors":"K. Fukui, K. Kakeda","doi":"10.1266/JJG.69.537","DOIUrl":"https://doi.org/10.1266/JJG.69.537","url":null,"abstract":"A critical evaluation of the digital data of 250 barley metaphase spreads obtained by image analysis revealed the instability of the chromosomal morphology during the mitotic metaphase stage. Both the relative length (RL) and arm ratio (AR) of the chromosomes, which are the two major numerical parameters in karyotype analysis, varied in the different chromosomal spreads. The ranking of the chromosomes for the respective parameters within a complement changed accordingly. The data indicated that karyotype analysis based merely on the numerical parameters RL and AR may lead to the misidentification of chromosomes, causing a misinterpretation of the data from different chromosomes when averaging several data. Thus, most of data of the RL and AR which have so far been reported may need reexamination except for the cases where chromosomes were identified based oh other critical parameters, e.g., banding pattern, condensation pattern, in situ hybridization, etc. Differential condensation between the chromosome arms may be the cause of the instability of the karyotype.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"329 1","pages":"537-544"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77402901","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}
Plasmid-like DNAs were isolated from mitochondria in many stocks of Para- mecium caudatum. Fifty-two among 68 stocks examined contained unique double-stranded DNAs (designated type I) ranging from 6.0 to 6.8 kb in length, and 12 stocks contained a set of 4 kinds of DNAs (8.2, 4.1, 2.8 and 1.4 kb; type II). Five of the stocks containing the type-I DNA had an additional 8.9-kb DNA (type III). No plasmid-like DNAs were found in the remaining 4 stocks. All these DNAs are linear and closely associated with proteins which can be removed only after proteinase-K digestion, suggesting that they exist as unique DNA protein complexes in mitochondria. Restriction and Southern blot analyses revealed a large sequence divergence among both type-I and -II DNAs. Type-I DNAs were found in every lineages of mitochondrial genomic DNA (mtDNA) which were inferred from restriction analyses. Type-II DNAs were, in contrast, scattered throughout the evolutionary tree of the mtDNAs. No obvious relations were found between the distribution of the DNAs and that of syngens (mating-type groups). Type-I DNAs were also found in other species of Paramecium, P. jenningsi and P. multimicronucleatum, and type-II DNAs in P. polycaryum.
{"title":"Distribution and genetic variabilities of mitochondrial plasmid-like DNAs in Paramecium","authors":"Y. Tsukii, H. Endoh, K. Yazaki","doi":"10.1266/JJG.69.685","DOIUrl":"https://doi.org/10.1266/JJG.69.685","url":null,"abstract":"Plasmid-like DNAs were isolated from mitochondria in many stocks of Para- mecium caudatum. Fifty-two among 68 stocks examined contained unique double-stranded DNAs (designated type I) ranging from 6.0 to 6.8 kb in length, and 12 stocks contained a set of 4 kinds of DNAs (8.2, 4.1, 2.8 and 1.4 kb; type II). Five of the stocks containing the type-I DNA had an additional 8.9-kb DNA (type III). No plasmid-like DNAs were found in the remaining 4 stocks. All these DNAs are linear and closely associated with proteins which can be removed only after proteinase-K digestion, suggesting that they exist as unique DNA protein complexes in mitochondria. Restriction and Southern blot analyses revealed a large sequence divergence among both type-I and -II DNAs. Type-I DNAs were found in every lineages of mitochondrial genomic DNA (mtDNA) which were inferred from restriction analyses. Type-II DNAs were, in contrast, scattered throughout the evolutionary tree of the mtDNAs. No obvious relations were found between the distribution of the DNAs and that of syngens (mating-type groups). Type-I DNAs were also found in other species of Paramecium, P. jenningsi and P. multimicronucleatum, and type-II DNAs in P. polycaryum.","PeriodicalId":22578,"journal":{"name":"The Japanese Journal of Genetics","volume":"29 1","pages":"685-696"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76230316","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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