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Volume 69 (1994)
- Issue 6 Pages 619-
- Issue 5 Pages 455-
- Issue 4 Pages 347-
- Issue 3 Pages 227-
- Issue 2 Pages 101-
- Issue 1 Pages 1-
Volume 69, Issue 4
Displaying 1-8 of 8 articles from this issue
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ARTICLES
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Yasunari OGIHARA, Kazuhiro ISONO, Akira SAITO1994 Volume 69 Issue 4 Pages 347-360
Published: 1994
Released on J-STAGE: September 10, 2004
JOURNAL FREE ACCESSSeventy 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.
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Minoru MURATA, Yutaka OGURA, Fusao MOTOYOSHI1994 Volume 69 Issue 4 Pages 361-370
Published: 1994
Released on J-STAGE: September 10, 2004
JOURNAL FREE ACCESSTwo highly repetitive DNA sequences have been cloned from Arabidopsis thaliana, ecotype Columbia, and were characterized by molecular and cytological analyses. These two sequences belong to the same repeat family with 180-bp basic unit, being tandemly organized in clusters. Pulsed field gel electrophoresis showed that this repeat sequence family forms at least seven clusters from ca. 100 to 1200 kb in length and ca. 3500 kb in total. Fluorescent in situ hybridization to somatic metaphase cells with the monomeric repeat unit as a probe clearly revealed that this repeat family is located at the centromeric regions of all chromosomes. It was also shown that this repetitive sequence is closely associated with limited parts of heterochromatic blocks on the centromeric regions which are visible distinctly at meiotic prophase from leptotene to diakinesis. Furthermore, this sequence hybridized preferentially to both polar sides of five bivalent chromosomes at the first metaphase. These results suggest that the repetitive sequences of this family were derived from the regions very close to the centromeres or on the centromeres themselves.
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Kozo NISHIKAWA, Shima MIZUNO, Yoshihiko FURUTA1994 Volume 69 Issue 4 Pages 371-376
Published: 1994
Released on J-STAGE: September 10, 2004
JOURNAL FREE ACCESSWith the aid of telocentric lines of Emmer wheat, the chromosomes involved in seven chromosome types (one standard type and six translocation types) in wild Emmer, Triticum dicoccoides, were identified. Type Ela was of almost the same chromosome structure as that of durum LD 222 with a small reciprocal translocation between chromosomes 4B and 2B. Type Elb had a major translocation between 2A and 2B and a minor one probably between 2B and 3B. Type E2 had a major translocation between 2B and 3B. Type E3 had a major translocation between 5B and 7B. Type E4 had a major translocation between 4B and 3B and a minor one between 2B and 4B or 3B. Type E5 had a major translocation between 6B and 7B. Type E6 had a major translocation between 1A and 5A. We discussed the result in comparison with the previously reported data on the same translocations.
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Hiroshi ENDOH1994 Volume 69 Issue 4 Pages 377-383
Published: 1994
Released on J-STAGE: September 10, 2004
JOURNAL FREE ACCESSTransformation 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 Tübingen-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.
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Toshinori ABE, Yasuhiro OKA, Takeo SASAHARA1994 Volume 69 Issue 4 Pages 385-396
Published: 1994
Released on J-STAGE: September 10, 2004
JOURNAL FREE ACCESSCalli initiated from 7 rice varieties belonging to 3 subspecies, indica, japonica, and javanica were cultured for 2 and 14 months on the callus maintenance medium, transferred to the plant regeneration medium, and various organ redifferentiation/plant regeneration abilities were examined. Considerable variations especially in the shoot regeneration were observed among the varieties; four varieties [Tadukan (indica), Nipponbare and Sasanishiki (japonica) and Allorio (javanica)] retained the same redifferentiation abilities, while the remaining 3 varieties [Fujisaka 5 (japonica) and Te-tep and Choukoutou (indica)] showed only very much lowered abilities after 14 months. During the redifferentiation/regeneration period, samples were taken at 4-day intervals up to 36 days and peroxidase and acid phosphatase activities were measured. Activities of these enzymes increased after transfer to the regeneration medium. The patterns of the increase, although the same among varieties within the same subspecies, differed markedly between subspecies. Significant correlations between the redifferentiation/regeneration abilities and the activities of the two enzymes were observed.
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Hitoshi SUZUKI, Tetsuji HOSODA, Susumu SAKURAI, Kimiyuki TSUCHIYA, Isa ...1994 Volume 69 Issue 4 Pages 397-406
Published: 1994
Released on J-STAGE: September 10, 2004
JOURNAL FREE ACCESSWe 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 (Felis bengalensis). 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 (F. catus) with an estimated sequence divergence of 1.5% and from that of the ocelot (F. paradalis) 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.
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Masahiro HIZUME1994 Volume 69 Issue 4 Pages 407-415
Published: 1994
Released on J-STAGE: September 10, 2004
JOURNAL FREE ACCESSAllium wakegi Araki could be originated from cross hybridization between close relatives of a form of A. cepa and A. fistulosum. Chromosomes of each parental haploid set were identified in the chromosome complement of A. wakegi by genomic in situ hybridization using probes of the total, parental genomic DNAs of A. cepa and A. fistulosum, respectively. The results of GISH suggested significant differentiation of genomic DNAs between these closely related species. Allium cepa had two 5S rDNA loci at the interstitial regions of the short arms of small chromosome pair (the 7th pair) and A. fistulosum had one locus at the interstitial region of the homologous short arms. Allium wakegi had two chromosomes carrying one and two 5S rDNA loci which appeared to correspond to those of A. fistulosum and A. cepa, respectively. Chromosomes carrying 18S rDNA loci originated from those of both A. cepa and A. fistulosum were also observed in the chromosome complement of A. wakegi.
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Masayoshi SHIGYO, Yosuke TASHIRO, Sadami MIYAZAKI1994 Volume 69 Issue 4 Pages 417-424
Published: 1994
Released on J-STAGE: September 10, 2004
JOURNAL FREE ACCESSThe 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.
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