Hokkaido University Collection of Scholarly and Academic Papers
(65.354 recursos)
HUSCAP (Hokkaido University Collection of Scholarly and Academic Papers) contains peer-reviewed journal articles, proceedings, educational resources and any kind of scholarly works of Hokkaido University.
Mostrando recursos 1 - 20 de 93
1.
Gene Expression of Autographa californica multiple Nucleopolyhedrovirus (AcMNPV) in Mammalian Cells and Upregulation of Host β-actin Gene - Fujita, Ryosuke; Matsuyama, Takahiro; Yamagishi, Junya; Sahara, Ken; Asano, Shinichiro; Bando, Hisanori
The gene expression of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) was examined in two types of mammalian cells, human HeLa14 and hamster BHK cells. DNA microarray analysis followed by RT-PCR identified at least 12 viral genes transcribed in both HeLa14 cells and BHK cells inoculated with AcMNPV. 5'A RACE was carried out to examine the transcriptional fidelity of these genes in HeLa14 cells. The transcription of ie-1, ie-0 and gp64 was initiated at a baculovirus early gene motif, CAGT, accompanied by a TATA motif. In addition, the same splicing observed for ie-0 mRNA in Sf9 cells occurred in HeLa14 cells. While...
2.
DNA methylation is not necessary for the inactivation of the Tam3 transposon at non-permissive temperature in Antirrhinum - Hashida, Shin-nosuke; Kishima, Yuji; Mikami, Tetsuo
It has been proposed that DNA methylation plays an important role in the inactivation of transposons. This view stems from a comparison of the degree of methylation of transposons in the active and inactive state. However, direct evidence for the degree of methylation required for the suppression of transposition has not been reported. Transposon Tam3 in Antirrhinum majus undergoes somatic reversal of its transposition activity, which is tightly controlled by temperature: low temperature around 15℃ permits transposition, high temperatures around 25℃ strongly inhibits it. Our previous study had shown that the methylation state of the Tam3 end regions is negatively...
3.
Inhibition of stem elongation in spinach by theobroxide - Kong, Fanjiang; Gao, Xiquan; Nam, Kyong-Hee; Takahashi, Kosaku; Matsuura, Hideyuki; Yoshihara, Teruhiko
In the current studies, we investigated the influences of theobroxide on stem elongation in spinach (Spinacia oleracea L.). Our results showed that stem elongation and flower formation were inhibited by spraying spinach plants with theobroxide under inductive, long day conditions (16 h light/8 h dark), while application of exogenous applied GA3 prevented the effect of theobroxide. Quantitative analysis showed that theobroxide suppressed GA1 biosynthesis, whereas the endogenous content of jasmonic acid was unchanged. However, under short day conditions (10 h light/14 h dark), there were no differences in stem length between treated and untreated plants. These results suggest that the...
4.
Allene oxide cyclase is essential for theobroxide-induced jasmonic acid biosynthesis in Pharbitis nil - Kong, Fanjiang; Abe, Jun; Takahashi, Kosaku; Matsuura, Hideyuki; Yoshihara, Teruhiko; Nabeta, Kensuke
Theobroxide, a natural product, strongly stimulates the biosynthesis of jasmonic acid (JA) in Pharbitis nil. In this study, we investigated the accumulation of protein by the immunoblot analysis of lipoxygenase (LOX), allene oxide synthase (AOS) and allene oxide cyclase (AOC), key enzymes in JA biosynthesis, and how the endogenous levels of JA in Pharbitis nil are affected by theobroxide. The effect of JA on the accumulations of these proteins was monitored simultaneously. The results show that theobroxide treatment led to a high level accumulation of JA, which is due to high accumulations of LOX, AOS and AOC proteins induced by...
5.
Theobroxide inhibits stem elongation in Pharbitis nil by regulating jasmonic acid and gibberellin biosynthesis - Kong, Fanjiang; Gao, Xiquan; Nam, Kyong-Hee; Takahashi, Kosaku; Matsuura, Hideyuki; Yoshihara, Teruhiko
In this study, exogenous factors affecting the elongation growth in the short day plant, Pharbitis nil, was investigated. Theobroxide inhibited stem elongation in Pharbitis nil both under short day (SD) and long day (LD) conditions. Salicylhydroxamic acid (SHAM), an inhibitor of jasmonic acid (JA) biosynthesis, and GA3 recovered the inhibitory effect of theobroxide on stem elongation. Quantitative analysis of JA showed that the level of endogenous JA increased significantly in theobroxide treated plants, while exogenously applied GA3 and SHAM suppressed JA biosynthesis stimulated by theobroxide. The activity of lipoxygenase (LOX, the key enzyme of JA biosynthesis) also was stimulated by...
6.
α-Glucosidase inhibition of 6-hydroxyflavones. Part 3, Synthesis and evaluation of 2,3,4-trihydroxybenzoyl-containing flavonoid analogs and 6-aminoflavones as α-previous termglucosidasenext term inhibitors - Gao, Hong; Kawabata, Jun
The SAR studies suggested that the C-ring of baicalein (1) was not necessary for the activity, and validated the importance of 2,3,4-trihydroxybenzoyl structure of 1. Thus, a series of 2,3,4-trihydroxybenzoyl-containing flavonoid analogs were investigated for the α-previous termglucosidasenext term inhibitory activity. The results indicated that 5,6,7-trihydroxy-2-phenyl-4-quinolone (2) and 5,6,7-trihydroxyflavanone (4) showed the comparable activity to 1, while 3,5,6,7-tetrahydroxyflavone (7), 5,6,7-trihydroxyisoflavone (8), and 6-hydroxygenistein (9) showed moderate α-previous termglucosidasenext term inhibitory activity. In addition, it was found that 6-amino-5,7-dihydroxyflavone (16) was a more potent and specific rat intestinal α-previous termglucosidasenext term inhibitor than 1, and showed the comparable activity to acarbose....
7.
Gene expression and genetic mapping analyses of a perennial ryegrass glycine-rich RNA-binding protein gene suggest a role in cold adaptation - Shinozuka, H; Hisano, H; Yoneyama, S; Shimamoto, Y; Jones, ES; Forster, JW; Yamada, T; Kanazawa, Akira
A perennial ryegrass cDNA clone encoding a putative glycine-rich RNA binding protein (LpGRP1) was isolated from a cDNA library constructed from crown tissues of cold-treated plants. The deduced polypeptide sequence consists of 107 amino acids with a single N-terminal RNA recognition motif (RRM) and a single C-terminal glycine-rich domain. The sequence showed extensive homology to glycine-rich RNA binding proteins previously identified in other plant species. LpGRP1-specific genomic DNA sequence was isolated by an inverse PCR amplification. A single intron which shows conserved locations in plant genes was detected between the sequence motifs encoding RNP-1 and RNP-2 consensus protein domains. A...
8.
A novel preparation of microcast for wood micromorphology using polydimethylsiloxane without digesting cell wall - Uraki, Yasumitsu; Nemoto, Junji; Sano, Yuzou
We developed a novel method for preparation of microcasts of wood with silicone elastomer (polydimethylsiloxane; PDMS). PDMS was so flexible and elastic that it was possible to isolate the microcasts by simply pulling them out of the mold without digesting the cell wall after the resin was cured for 2 days at room temperature. The casts of some cell wall sculptures, such as spiral thickenings and bordered pits, had high fidelity. By contrast, the casts of distinctly bordered pits and tails of vessel elements were often deformed or broken. Bars of scalariform perforation plates were always torn and remained in...
9.
Ingestion of difructose anhydride III partially restores calcium absorption impaired by vitamin D and estrogen deficiency in rats - Mitamura, Rieko; Hara, Hiroshi
Background Vitamin D (VD) and estrogen deficiencies impair Ca absorption and bone mineralization, and the relevance of the interaction between these factors has not been fully understood.
Aim of the study The aim of the present study was to clarify the effects of a nondigestible saccharide, difructose anhydride III (DFAIII), on the interaction of VD and estrogen deficiencies involved in Ca malabsorption by assessing changes in intestinal Ca absorption and bone mineralization by feeding of DFAIII in rats with VD or estrogen deficiency or with a combined loss of VD and estrogen.
Methods Three-week-old female Sprague-Dawley rats were divided into four groups:...
10.
The regulatory function of the upstream sequence of the beta-conglycinin alpha subunit gene in seed-specific transcription is associated with the presence of the RY sequence - Yoshino, Michiko; Nagamatsu, Atsushi; Tsutsumi, Ken-ichi; Kanazawa, Akira
β-conglycinin, a major component of seed-storage proteins in soybean, comprises three subunits: α, α', and β. Expression of these genes is spatially regulated in a stringent manner and occurs during seed development. To understand the mechanisms that control expression of the α subunit gene, we analyzed the nucleotide sequence of the 2.9-kb region upstream of the gene. The upstream sequence up to –1357 or a series of its 5'-deleted derivatives was fused to the β-glucuronidase (GUS) gene. These reporter gene constructs were introduced into Arabidopsis thaliana plants via Agrobacterium-mediated gene transfer. Prominent GUS activity was detected in developing seeds of...
11.
DPPH (=2,2-diphenyl-1-picrylhydrazyl=2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) radical-scavenging reaction of protocatechuic acid esters (=3,4-dihydroxybenzoates) in alcohols : Formation of bis-alcohol adduct - Saito, Shizuka; Gao, Hong; Kawabata, Jun
Protocatechuic acid esters (=3,4-dihydroxybenzoates) scavenge ca. 5 equiv. of radical in alcoholic solvents. whereas they consume only 2 equiv. of radical in nonalcoholic solvents. While the high radical-scavenging activity of protocatechuic acid esters in alcoholic solvents as compared to that in nonalcoholic solvents is due to a nucleophilic addition of an alcohol molecule at C(2) of an intermediate o-quinone structure, thus regenerating a catechol (=benzene-1,2-diol) structure, it is still unclear why protocatechuic acid esters scavenge more than 4 equiv. of radical (C(2) refers to the protocatechuic acid numbering). Therefore, to elucidate the oxidation mechanism beyond the formation of the C(2)...
12.
Difructose anhydride III and sodium caprate activate paracellular transport via different intracellular events in Caco-2 cells - Suzuki, Takuya; Hara, Hiroshi
A nondigestible disaccharide, difructose anhydride (DFA) III, is known to activate calcium transport via tight junctions (TJs); however, the characteristics of and mechanisms for the increase in paracellular transport induced by DFAIII have not been clarified. We compared the effect of DFAIII with that of sodium caprate (C10), a well-known enhancer of TJ permeability, on the changes in TJ proteins, transport of paracellular markers, and effects of nine cellular signaling blockers using Caco-2 monolayers. The addition of DFAIII (0-100mmol/L) and C10 (0-10mmol/L) to the apical medium of the Caco-2 monolayers dose-dependently decreased transepithelial electrical resistance (TER), which is an indicator...
13.
Double copulation of a female with sterile diploid and polyploid males recovers fertility in Bombyx mori - Sahara, Ken; Kawamura, Naoko
Silkworm males produce dimorphic sperm, nucleate eupyrene sperm and anucleate apyrene sperm.
Apyrene sperm have been speculated to have an assisting role in fertilisation. However, the coexistence
of eupyrene and apyrene sperm in the testis and female reproductive organs has made it difficult to
define the role of apyrene sperm. Polyploid males are highly sterile. Microscopic observation revealed
that the elimination of eupyrene nuclei by peristaltic squeezing caused the sterility of polyploids. Heatshock
applied to pupae of Daizo males (DH) also induced high sterility due to the lack of normal apyrene
sperm. When eupyrene sperm of sterile DH males and apyrene sperm of sterile polyploid males...
14.
Significance of peristaltic squeezing of sperm bundles in the silkworm, Bombyx mori: elimination of irregular eupyrene sperm nuclei of the triploid - Sahara, Ken; Kawamura, Naoko; Yamashiki, Naoko; Saitoh, Hiroshi
Silkworm (Lepidoptera) males produce dimorphic sperm: nucleate eupyrene sperm and anucleate apyrene sperm. The eupyrene sperm are ordinary sperm to fertilise the eggs, while the function of apyrene sperm remains uncertain. After meiosis, 256 sperm cells are enclosed by a layer of cyst cells, forming a sperm bundle. We have previously documented that the nucleus of eupyrene sperm anchors to the head cyst cell, which locates at the anterior apex of the bundle, by an acrosome tubule-basal body assembly. Neither the basal body attachment to the nucleus nor the acrosome is seen in apyrene sperm, and the nuclei remain in...
15.
Application of artificial insemination technique to eupyrene and/or apyrene sperm in Bombyx mori - Sahara, Ken; Takemura, Yoko
The silkworm, Bombyx mori, has a dimorphic sperm system. The eupyrene sperm
is the sperm to fertilize eggs and the apyrene sperm plays a crucial role for assisting fertilization.
Heat-treated (331C for 96h) Daizo (DH) males, one of the strains in the silkworm, produce only
eupyrene sperm, while in triploid males only apyrene sperm are functional. Though both types of
males are found to be sterile, double copulation of the two males with a single female greatly
increases fertility. Here we examined the fertilizing ability of eupyrene and apyrene sperm by means
of an artificial insemination technique previously established in B. mori. Neither the eupyrene
sperm collected...
16.
Resolution of sex chromosome constitution by genomic in situ hybridization and fluorescence in situ hybridization with (TTAGG) n telomeric probe in some species of Lepidoptera - Yoshido, Atsuo; Marec, František; Sahara, Ken
Abstract We have developed a simple method to resolve
the sex chromosome constitution in females of Lepidoptera
by using a combination of genomic in situ hybridization
(GISH) and fluorescence in situ hybridization with
(TTAGG)n telomeric probe (telomere-FISH). In pachytene
configurations of sex chromosomes, GISH differentiated
W heterochromatin and telomere-FISH detected the chromosome
ends.With this method we showed that Antheraea
yamamai has a standard system with a fully differentiated
W–Z sex chromosome pair. In Orgyia antiqua, we confirmed
the presence of neo-W and neo-Z chromosomes,
which most probably originated by fusion of the ancestral
W and Z with an autosome pair. In contrast to earlier
data, Orgyia thyellina females displayed a neo-ZW1W2
sex chromosome constitution....
17.
Roles of actin networks in peristaltic squeezing of sperm bundles in Bombyx mori - Sahara, Ken; Kawamura, Naoko
Two types of sperm are produced in the silkworm, Bombyx mori. Nucleate eupyrene sperm is an ordinary sperm that contributes to fertilization, while anucleate apyrene sperm is considered to play important roles in assisting eupyrene sperm. At the very late stage of spermatogenesis, a phenomenon called peristaltic squeezing occurs in both types of sperm, whereby cytoplasm of the eupyrene and nuclei of the apyrene sperm are discarded from the posterior end, forming matured sperm. In this study, rhodamine-phalloidin staining for actin was applied to sperm bundles. Before the start of peristaltic squeezing, actin filament networks are spread on the cyst...
18.
W-derived BAC probes as a new tool for identification of the W chromosome and its aberrations in Bombyx mori - Sahara, Ken; Yoshido, Atsuo; Kawamura, Naoko; Ohnuma, Akio; Abe, Hiroaki; Mita, Kazuei; Oshiki, Toshikazu; Shimada, Toru; Asano, Shin-ichiro; Bando, Hisanori; Yasukochi, Yuji
We isolated four W chromosome-derived bacterial artificial chromosome (W-BAC) clones from Bombyx mori BAC libraries by the polymerase chain reaction and used them as probes for fluorescence in situ hybridization (FISH) on chromosome preparations from B. mori females. All four W-BAC probes surprisingly highlighted the whole wild-type W sex chromosome and also identified the entire original W-chromosomal region in W chromosome-autosome translocation mutants. This is the first successful identification of a single chromosome by means of BAC-FISH in species with holokinetic chromosomes. Genomic in situ hybridization (GISH) by using female-derived genomic probes highlighted the W chromosome in a similar chromosome-painting...
19.
Moth sex chromatin probed by comparative genomic hybridization (CGH) - Sahara, Ken; Marec, František; Eickhoff, Ulrike; Traut, Walther
Comparative genomic hybridization (CGH) with a probe mixture of differently labeled
genomic DNA from females and males highlighted the W chromosomes in mitotic plates and the W
chromatin in polyploid interphase nuclei of the silkworm Bombyx mori, the flour moth Ephestia
kuehniella, and the wax moth Galleria mellonella. The overproportionate fluorescence signal
indicated an accumulation of repetitive sequences in the respective W chromosomes. Measurements
of the fluorescence signals revealed two components, one that is present also in male DNA (non-W
chromosomes) and another one that is present only in or preponderantly in female DNA (W
chromosomes). While the W chromosomes of E. kuehniella and G. mellonella had...
20.
In vitro cultivation of spermatocysts to matured sperm in the silkworm Bombyx mori - Kawamura, Naoko; Sahara, Ken
Bombyx spermatogonia are bipotential, producing nucleate eupyrene sperm and anucleate apyrene sperm. An in vitro cultivation of spermatocysts of Bombyx mori from spermatocytes to matured sperm was established. The present experiment made clear that: (i) spermatocysts must be isolated; (ii) constant shaking at 45 r.p.m. was necessary; and (iii) the addition of Bombyx hemolymph (BH) was indispensable for successful cultivation. In the absence of BH, spermatogenesis proceeded normally for 2 or 3 days and, thereafter, spermatocytes and sperm bundles began to degenerate. The best results for normal eupyrene spermatogenesis were obtained when culture medium containing BH of the corresponding stage...
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