巻号一覧
63 巻, 4 号
選択された号の論文の7件中1～7を表示しています
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I. Chromosome constitutions and reproductive properties of both parental and progeny plantsAkinori UCHINO, Kazunari TANAKA1988 年 63 巻 4 号 p. 283-293
発行日: 1988年
公開日: 2006/07/25
ジャーナル フリーOne diploid plant with 2n=18 and 26 aneuploids with 2n=37 to 60 of different ploidy levels were obtained among open-pollinated progeny plants from the asynaptic amphidiploid plants (2n=34+4f+2F, AABB) of Scilla scilloides.
This species is a long-lived perennial herb propagating vegetatively by bulb multiplication, as well as sexually by seed production. On the both parental and progeny plants, reproductive properties were analyzed in comparison with those of the normal amphidiploid plants. In the parental asynaptic plants, the majority of pollen grains revealed a very low fertility which varied slightly among clonal plants and years, the average value being 5.50%. The seed setting rate was vely low, the average value being 1.8% in 1969, and 1.2% in 1970. Some of the seeds germinated in the following spring. Thus, asynaptic plants were capable of sexually producing a few progenies. They have also produced on the average 16.7 bulblets during ten years. As for the progeny plants with various chromosome numbers, the pollen fertility was greatly variable among plants, from 10.3 to 96.0%. The seed setting rate and germination rate were considerably variable among progeny plants, and were, as a whole, lower than those of the normal amphidiploid plants, similar to the case of pollen fertility. All progeny plants reproduced also vegetatively during 16 or 17 years.抄録全体を表示PDF形式でダウンロード (1315K) -
Nobuhiko ASADA1988 年 63 巻 4 号 p. 295-301
発行日: 1988年
公開日: 2006/07/25
ジャーナル フリーA large genetic variation in pyokori-like jumping behavior was found among the wild flies of the Drosophila nasuta subgroup belonging to the D. immigrans species group. The parallel relationship between phylogenetic divergence and the degree of pyokori-like jumping behavior was demonstrated; that is, the ancestral species, D. pallidifrons, responded more actively than the derived species, e.g., D. kepulauana. Hence this behavior might be used as a marker response for the study of the evolutionary process of Drosophila.抄録全体を表示PDF形式でダウンロード (248K) -
Eiji NITASAKA, Tsuneyuki YAMAZAKI1988 年 63 巻 4 号 p. 303-312
発行日: 1988年
公開日: 2006/07/25
ジャーナル フリーThe X-linked singed locus is concerned with the bristle phenotype and female sterility, and is known as a hot spot of P element insertion. A moderate allele of singed, singed-weak (snw) (Engels, 1979; 1984) is inserted with P elements. It is used as an index of P element activity, since it mutates at a high frequency to either a more extreme allele, singed-extreme (sne), or to a phenotype that is equivalent to the wild type (sn+) when an autonomous P element exists. We show here that snw is inserted with two defective P elements in reverse orientation, and the two alternate mutational events (sn+ and sne) are caused by the excision of one or the other of the P elements present in the singed gene. It is interesting that sn+ and sne are inserted with a single P element in the same position, but show very different phenotypes. The insertional sites of P elements in the singed locus possibly contain an unidentified repetitive sequence, which is repeated dozens of times per haploid genome of the wild-type strain Canton-S.抄録全体を表示PDF形式でダウンロード (610K) -
II. The fusion burst in man and mouseHirotami T. IMAI, Naoyuki TAKAHATA, Takeo MARUYAMA, Art DANIEL, Takeo ...1988 年 63 巻 4 号 p. 313-342
発行日: 1988年
公開日: 2006/07/25
ジャーナル フリーAs a theoretical standard for evaluating the high incidence of centric fusion in man and mouse, the relative probabilities of occurrence of reciprocal translocation (Tr), inversion (In) and centric fusion (Fu) were estimated based on the random- contact-and-exchange model. It was shown by this model that centric fusion was extremely rare (Fu=0.0002, In=0.0521 and Tr=0.9477 for a human haploid karyotype). On the other hand, the occurrence rate of centric fusion in human newborn babies and European feral mice was about 500-1, 000 times higher than the theoretically expected values, which is termed here the "fusion burst". We suggest that the fusion burst may be induced by the physical proximity of telomeres on the nuclear membrane, and the exchange of DNA strands by errors of telomere replication mechanisms. The cytogenetical significance of the fusion burst is discussed with regard to the minimum interaction hypothesis proposed by Imai et al. (1986). We suggest two closely linked possibilities that (1) the fusion burst in man and mouse can theoretically be placed in karyotype evolution as a transitional phase in the main stream of the fission-inversion cycle, and (2) it may be accelerated by some unknown (mutagenic) factors other than ionizing radiation.抄録全体を表示PDF形式でダウンロード (1220K) -
Kuniharu OHNISHI, Akira HASEGAWA, Keiko MATSUBARA, Takayasu DATE, Tosh ...1988 年 63 巻 4 号 p. 343-357
発行日: 1988年
公開日: 2006/07/25
ジャーナル フリーThe genetically difined gleR-brnQ region responsible for the branched-chain amino acid transport in Salmonella typhimurium was mapped in the 3.3-kilobase SalI-PstI segment of plasmid pOH56 by complementation analysis. By subcloning and genetic recombination analysis, the gleR and brnQ3 mutational sites were localized within the 0.85-kilobase SalI-EcoRV segment, and brnQ4 within the 0.8-kilobase EcoRV-HindIII segment. The nucleotide sequence of the brnQ gene and its flanking regions was determined. The brnQ gene is encoded by the sequence starting 24 base pairs upstream from the EcoRV site. Transcription of the brnQ gene starts at three sites separated by 171, 173 and 174 nucleotides, respectively, from the initiation colon. The promoter sequences can be seen in the immediate upstream region of the transcription initiation sites. There is a long silent region between the transcription initiation sites and a potential Shine-Dalgarno nucleotide sequence. The coding sequence of the brnQ gene, which is 1317 base pairs long, specifies a very hydrophobic protein of 439 amino acid residues.抄録全体を表示PDF形式でダウンロード (702K) -
Kiichi FUKUI, Yasuhiko MUKAI1988 年 63 巻 4 号 p. 359-366
発行日: 1988年
公開日: 2006/07/25
ジャーナル フリーThe method of using conventional numerical parameters, such as length and arm ratio, is insufficient to distinguish the chromosomes of Atriplex rosea L. (2n=18) completely, as they are very small. Therefore a new image parameter, condensation pattern (CP), was defined and employed to obtain additional information for chromosome identification. The CP of a chromosome was represented by a profile line of the density distribution along the midrib of unilateral chromatid, and was measured semi-automatically by the CHromosome Image Analyzing System, CHIAS. It was shown that the CP is a valuable parameter for identification of the small chromosomes in plants.抄録全体を表示PDF形式でダウンロード (861K) -
Kei-ich KUMA, Hidenori HAYASHIDA, Takashi MIYATA1988 年 63 巻 4 号 p. 367-371
発行日: 1988年
公開日: 2006/07/25
ジャーナル フリーNucleotide sequences of the human X-linked red and green pigment genes were compared, and the number of silent substitutions per site (KSc) between these genes was analysed in comparison with the corresponding values of primate genes. Taking the retarded mutation rate of X-linked genes into consideration (Miyata et al., 1987), the red and green pigment genes were shown to have undergone gene conversion at around the time of separation of African apes and orangutan. Thus the recent gene conversion and retarded mutation rate in these X-linked genes are probably responsible for the strong sequence similarity between these genes, which is likely to facilitate the occurrence of red-green color blindness in the human population. It was also shown that the red pigment gene evolved about five times more rapidly than the green pigment gene since the latest gene conversion.抄録全体を表示PDF形式でダウンロード (253K)
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