巻号一覧
69 巻, 3 号
選択された号の論文の8件中1～8を表示しています
- |<
- <
- 1
- >
- >|
ARTICLES
-
Sangvorn KITTHAWEE, Visut BAIMAI1994 年 69 巻 3 号 p. 227-231
発行日: 1994年
公開日: 2004/08/11
ジャーナル フリーCytological investigations of salivary gland polytene chromosomes of the Drosophila kikkawai complex in Thailand have revealed an interesting pattern of species divergence. Drosophila bocki, D. leontia and D. kikkawai share chromosome arrangement 3LB. However, additional gene arrangements of 3LA and 3LC have been observed in D. kikkawai and D. leontia, respectively, while D. bocki remains polymorphic for inversion 3LB. Chromosomal evidence seems to suggest that D. bocki is similar to a common ancestor of the D. kikkawai complex.
抄録全体を表示PDF形式でダウンロード (631K) -
Myriam HARRY1994 年 69 巻 3 号 p. 233-250
発行日: 1994年
公開日: 2004/08/11
ジャーナル フリーMorphometric variability was studied in six domestic Venezuelan populations of the blood-sucking bug Rhodnius prolixus Stal 1897 (Reduviidae, Triatominae) and in a sylvatic population identified as R. robustus Larrousse 1927. Evidence is here provided by both uni- and multifactorial analyses of extensive variation of morphological traits between the R. prolixus populations studied. Regardless the geographic or climatic environmental factor tested, none can be retained in a selective model accounting for the morphological variability observed. Moreover, the results failed to support any correlation between the morphological Mahalanobis' distances and geographical distances. The genetic relationships between these populations inferred from the present data, are more consistent with some demic structure, resulting from random genetic drift by founder effects, than with any alternative population genetic model. It is noteworthy that the range of variation of these morphological traits in R. prolixus includes the putative R. robustus population. Therefore, the species-specific status of R. robustus, at the very least the local Trujillo population studied, is questioned. In addition, a preliminary multifactorial analysis bearing on three other Rhodnius relatives, R. pictipes Stal 1872, R. nasutus Stal 1859 and R. neglectus Lent 1954, confirmed the marked morphological differentiation of R. pictipes from all other species and showed a clear morphological differentiation of R. nasutus and R. neglectus both from one another and from R. prolixus.
抄録全体を表示PDF形式でダウンロード (2792K) -
Hiroki SHIBATA, Tsuneyuki YAMAZAKI1994 年 69 巻 3 号 p. 251-258
発行日: 1994年
公開日: 2004/08/11
ジャーナル フリーA comparative study was done on the enzymological features of α-amylase among six sibling species belonging to the Drosophila melanogaster species subgroup. The pH optima were 7.6 for D. melanogaster, D. mauritiana and D. simulans and 7.4 for D. erecta, D. teissieri and D. yakuba. The temperature optima were commonly 37 C in all species studied. However, there are two types of temperature dependence; a strict one as observed in D. melanogaster, D. mauritiana and D. simulans, and a flat one as observed in D. erecta, D. teissieri and D. yakuba. These separations are consistent with the general phylogeny within this species subgroup. The substrate dependence was almost the same in all the species studied. The V max and Km were also estimated for each species. We found clear differences in the enzymological features between the species. Thus these differences might reflect an adaptation of the amylase enzyme system to speciation in this species subgroup.
抄録全体を表示PDF形式でダウンロード (941K) -
Naohiko SEKI, Satoshi ISHIKIRIYAMA, Masatake YAMAUCHI, Tada-aki HORI1994 年 69 巻 3 号 p. 259-267
発行日: 1994年
公開日: 2004/08/11
ジャーナル フリーFragile X syndrome is the most common familial form of mental retardation and known to be associated with the fragile site at Xq27.3 (FRAXA). The syndrome has recently been characterized by a unique genetic mechanism which involves dynamic mutation due to a heritable unstable DNA sequence, p(CCG)n repeat, in the FRAXA locus. We were asked to make a genetic diagnosis on the case of a normal male who has two brothers and a maternal uncle with mental retardation. We performed the pedigree analysis of the fragile X syndrome using both cytogenetic and molecular techniques. The affected two brothers and the uncle showed cytogenetic expression of the fra (X)(q27.3) and carried hypermethylated full mutation in the FRAXA locus. The phenotypically normal mother also exhibited fragile X expression and was found to be a carrier of premutation. Via female transmission, the premutation converted to full mutation and exhibited somatic heterogeneity and hypermethylation. However, both cytogenetic and molecular data did not show any evidence of fragile X mutation in the normal male client and, thus, excluded the possibility of his being a carrier.
抄録全体を表示PDF形式でダウンロード (1252K) -
Takafumi MAEKAWA, Eiichi OHTSUBO1994 年 69 巻 3 号 p. 269-285
発行日: 1994年
公開日: 2004/08/11
ジャーナル フリーTo analyze the region that determines the specificity of binding of the Tn3 transposase to the terminal inverted repeat sequences (IR), we first determined the nucleotide sequence of a Tn3-family transposon, γδ, which is supposed to encode a transposase similar to that of Tn3. γδ was 5981 bp in length and contained three coding frames: Two were the genes, tupA and tnpR, encoding transposase (1002 amino acids) and resolvase/repressor (183 amino acids), respectively, and the third, named tnpX, encoding a protein (698 amino acids) of unknown function but containing two NTP-binding motifs. Utilizing the tnpA sequence, we then constructed a series of Tn3-γδ hybrid genes encoding chimeric proteins in the N-terminal segments of the transposases (amino acid position 1 to 242 of Tn3 or 1' to 243' of γδ), which has been previously shown to be responsible for specific binding of transposase to IR sequences in Tn3. Examination of their DNA-binding activities revealed that the subsegment of the N-terminus from amino acid position 1 to 109 determines the specificity of binding to the IR sequences. The third coding frame found in γδ, tnpX, is located downstream of tnpR and is expressed from the tnpR promoter in the absence of the tnpR gene product, resolvase/repressor, to produce a protein that inhibits the growth of the host cells. Possible roles of this protein are discussed.
抄録全体を表示PDF形式でダウンロード (2586K) -
Fumio TAJIMA, Tohru TOKUNAGA, Naohiko T. MIYASHITA1994 年 69 巻 3 号 p. 287-295
発行日: 1994年
公開日: 2004/08/11
ジャーナル フリーIn order to understand the evolutionary process of self-incompatibility, we must know the genetic variability of the self-incompatibility genes within and between populations. Statistical methods for estimating the effective number of alleles, expected heterozygosity and genetic distance from pollination experiments were developed, which can be applied to both gametophytic and sporophytic self-incompatibility systems. In these methods, bud-pollination, which is necessary for obtaining homozygotes, is not required. Since bud-pollination, which is time-consuming, is not required in the present methods, they might be useful.
抄録全体を表示PDF形式でダウンロード (1042K) -
Naohiko T. MIYASHITA, Charles H. LANGLEY1994 年 69 巻 3 号 p. 297-305
発行日: 1994年
公開日: 2004/08/11
ジャーナル フリーRestriction map polymorphism at two X linked loci, forked and vermilion of Drosophila melanogaster was studied in three natural populations. The estimates of nucleotide variation were θ = 0.003 and π = 0.002 for the forked region and θ =0.004 and π =0.002 for the vermilion region. Three insertions (>500 bp) were observed at each locus. Typical of other regions of this species each of these large insertions was unique in the sample. Non-random association among polymorphisms was common at the vermilion locus, while the forked locus was not polymorphic enough to test linkage disequilibrium. The amounts of restriction site and size variation in the vermilion and forked were within the range observed for other loci of D. melanogaster.
抄録全体を表示PDF形式でダウンロード (1072K) -
Yuuji TSUKII1994 年 69 巻 3 号 p. 307-319
発行日: 1994年
公開日: 2004/08/11
ジャーナル フリーMitochondrial DNAs (mtDNAs) from eight and unknown syngens of Paramecium caudatum, including stocks of different geographic origin, were investigated for their evolutionary relationships using restriction endonucleases. Thirty-six mtDNA variants as to the restriction patterns were identified within 61 natural stocks. Pair-wise comparison of the ratios of shared restriction fragments were used to construct an evolutionary tree, in which mtDNAs were genealogically classified into several distinct groups. Collecting localities of stocks in each mtDNA group were overlapped with those in other groups. Distribution of the mtDNA groups was also overlapped among syngens, i.e., each group included several syngens shared with other groups. Classification of mtDNAs thus did not conform to that of syngens. The possible reasons are natural hybridization among syngens resulting in the introgression of mtDNAs and/or mutations changing the mating-type specificities similar to those of other syngens, which lead to the multiple origin of the syngens. These two possibilities are discussed in relation to the situation of syngens in this species.
抄録全体を表示PDF形式でダウンロード (1597K)
- |<
- <
- 1
- >
- >|