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排序方式: 共有216条查询结果,搜索用时 109 毫秒
101.
Effect of dissolved oxygen concentration and impeller tip speed on itaconic acid production by Aspergillus terreus 总被引:1,自引:0,他引:1
Summary Effect of aeration rate and impeller tip speed on mycelium growth and itaconic acid production was investigated in a batch culture of Aspergillus terreus IFO-6365. When impeller tip speed was 94.2 cm/sec at a fixed aeration rate of 0.5 vvm, itaconic acid concentration was 3.6 and 1.6 times higher than those in the impeller tip speed of 62.8 and 125.7 cm/sec, respectively. When an oxygen-enriched air was supplied at a fixed impeller tip speed of 94.2 cm/sec and dissolved oxygen concentration was maintained in the 20–60 % range, both itaconic acid concentration and mycelium growth were not affected by the dissolved oxygen concentration. 相似文献
102.
Shogo Asano Atsushi Suzuki Sahoko Sekiguchi Keiko Nishiwaki-Yasuda Megumi Shibata Mitsuyasu Itoh 《Prostaglandins, leukotrienes, and essential fatty acids》2009,81(4):247-251
Inorganic phosphate (Pi) transport probably represents an important function of bone-forming cells in relation to extracellular matrix mineralization. In the present study, we investigated the effect of prostaglandin D2 (PGD2) on Pi transport activity and its intracellular signaling mechanism in MC3T3-E1 osteoblast-like cells. PGD2 stimulated Na-dependent Pi uptake time- and dose-dependently in MC3T3-E1 cells during their proliferative phase. A protein kinase C (PKC) inhibitor calphostin C partially suppressed the stimulatory effect of PGD2 on Pi uptake. The selective inhibitors of mitogen-activated protein (MAP) kinase pathways such as ERK, p38 and Jun kinases suppressed PGD2-induced Pi uptake. The inhibitors of phosphatidylinositol (PI) 3-kinase and S6 kinase reduced this effect of PGD2, while Akt kinase inhibitor did not. These results suggest that PGD2 stimulates Na-dependent Pi transport activity in the phase of proliferation of osteoblasts. The mechanisms responsible for this effect are activation of PKC, MAP kinases, PI 3-kinase and S6 kinase. 相似文献
103.
Yuji Hiwatashi Mari Obara Yoshikatsu Sato Tomomichi Fujita Takashi Murata Mitsuyasu Hasebe 《The Plant cell》2008,20(11):3094-3106
Microtubules form arrays with parallel and antiparallel bundles and function in various cellular processes, including subcellular transport and cell division. The antiparallel bundles in phragmoplasts, plant-unique microtubule arrays, are mostly unexplored and potentially offer new cellular insights. Here, we report that the Physcomitrella patens kinesins KINID1a and KINID1b (for kinesin for interdigitated microtubules 1a and 1b), which are specific to land plants and orthologous to Arabidopsis thaliana PAKRP2, are novel factors indispensable for the generation of interdigitated antiparallel microtubules in the phragmoplasts of the moss P. patens. KINID1a and KINID1b are predominantly localized to the putative interdigitated parts of antiparallel microtubules. This interdigitation disappeared in double-deletion mutants of both genes, indicating that both KINID1a and 1b are indispensable for interdigitation of the antiparallel microtubule array. Furthermore, cell plates formed by these phragmoplasts did not reach the plasma membrane in ∼20% of the mutant cells examined. We observed that in the double-deletion mutant lines, chloroplasts remained between the plasma membrane and the expanding margins of the cell plate, while chloroplasts were absent from the margins of the cell plates in the wild type. This suggests that the kinesins, the antiparallel microtubule bundles with interdigitation, or both are necessary for proper progression of cell wall expansion. 相似文献
104.
Okamoto O Kobayashi K Kawamoto H Ito S Satoh A Kato T Yamamoto I Mizutani S Hashimoto M Shimizu A Sakoh H Nagatomi Y Iwasawa Y Takahashi H Ishii Y Ozaki S Ohta H 《Bioorganic & medicinal chemistry letters》2008,18(11):3278-3281
Structure-activity studies on benzimidazole lead 1 obtained from library screening led to the discovery of potent and selective ORL1 antagonist 28, 5-chloro-2-[(1-ethyl-1-methylpropyl)thio]-6-[4-(2-hydroxyethyl)piperazin-1-yl]-1H-benzimidazole, which is structurally distinct from conventional non-peptide antagonists known to date. 相似文献
105.
Yoichi?TanabeEmail author Makoto?Uchida Mitsuyasu?Hasebe Motomi?Ito 《Journal of plant research》2003,116(1):69-73
Recent progress in plant molecular genetics has revealed that floral organ development is regulated by several homeotic selector
genes, most of which belong to the MADS-box gene family. Here we report on SrMADS1, a MIKCc-type MADS-box gene from Selaginella, a spikemoss belonging to the lycophytes. SrMADS1 phylogenetically forms a monophyletic clade with genes of the LAMB2 group, which are MIKCc genes of the clubmoss Lycopodium, and is expressed in whole sporophytic tissues except roots and rhizophores. Our results and the previous report on Lycopodium MIKCc genes suggest that the ancestral MIKCc gene of primitive dichotomous plants in the early Devonian was involved in the development of basic sporophytic tissues such
as shoot, stem, and sporangium.
Electronic Publication 相似文献
106.
107.
The present study was conducted to determine the mechanism of chalaza formation in eggs of the Japanese quail Coturnix japonica and to determine the production site of chalaza materials in the oviduct. Electrophoretic profiles of the chalaza materials
showed six bands of 480, 320, 210, 180, 96, and 58 kDa following Coomassie Blue staining and one band of 600 kDa after immunoblotting.
An antiserum was produced against the 180-kDa band. This antiserum and an antiserum generated against the 600-kDa protein
were used as probes to detect chalaza materials. Immunofluorescent and immunoelectron-microscopic observations revealed that
chalazae and chalaziferous layers overlaid to approximately 40 μm upon the vitelline membrane of the ovum were composed of
the same materials as those produced by both types of secretory cells in the luminal and glandular epithelia at the infundibulum.
We propose that the mechanism of chalaza formation is as follows: (1) chalazae first appear as fine filaments at the presumptive
sharp and blunt ends of the ovum at the infundibulum; (2) these filaments are twisted into a lead fiber while the ovum is
rotating and descending in the magnum; (3) at the posterior end of the magnum, the lead fiber is anchored to the thick egg
white and lifted outward with the chalaziferous sublayers when the inner egg white is liquefied by absorbing water; (4) the
lead fiber and chalaziferous sublayers are twisted further into the chalaza in the uterus. 相似文献
108.
Involvement of mitochondrial-targeted RecA in the repair of mitochondrial DNA in the moss, Physcomitrella patens 总被引:1,自引:0,他引:1
Homologous recombination is a universal process that contributes to genetic diversity and genomic integrity. Bacterial-type RecA generally exists in all bacteria and plays a crucial role in homologous recombination. Although RecA homologues also exist in plant mitochondria, there have been few reports about the in vivo functions of these homologues. We identified a recA gene orthologue (named PprecA1) in a cDNA library of the moss, Physcomitrella patens. N-terminal fusion of the putative organellar targeting sequence of PpRecA1 to GFP caused a targeting of PpRecA1 to mitochondria. PprecA1 partially complemented the effects of a DNA damaging agent in an Escherichia coli recA deficient strain. Additionally, the expression of PprecA1 was induced by treating the plants with DNA damaging agents. Disruption of PprecA1 by targeted replacement resulted lower rate of the recovery of the mitochondrial DNA from methyl methan sulfonate damage. This is the first report about the characteristics of a null mutant of bacterial-type recA gene in plant. The data suggest that PprecA1 participates in the repair of mitochondrial DNA in P. patens. 相似文献
109.
Evolution of Reproductive Organs in Land Plants 总被引:4,自引:0,他引:4
Mitsuyasu Hasebe 《Journal of plant research》1999,112(4):463-474
LEAFY gene is the positive regulator of the MADS-box genes in flower primordia. The number of MADS-box genes presumably increased
by gene duplications before the divergence of ferns and seed plants. Most MADS-box genes in ferns are expressed similarly
in both vegetative and reproductive organs, while in gymnosperms, some MADS-box genes are specifically expressed in reproductive
organs. This suggests that (1) the increase in the number of MADS-box genes and (2) the subsequent recruitment of some MADS-box
genes as homeotic selector genes were important for the evolution of complex reproductive organs. The phylogenetic tree including
both angiosperm and gymnosperm MADS-box genes indicates the loss of the A-function genes in the gymnosperm lineage, which
is presumably related to the absence of perianths in extant gymnosperms. Comparison of expression patterns of orthologous
MADS-box genes in angiosperms, Gnetales, and conifers supports the sister relationship of Gnetales and conifers over that
of Gnetales and angiosperms predicted by phylogenetic trees based on amino acid and nucleotide sequences.
Received 30 July 1999/ Accepted in revised form 9 September 1999 相似文献
110.
Hiroyuki Uehara Bok Du Choi Enoch Y. Park Mitsuyasu Okabe 《Biotechnology and Bioprocess Engineering》2000,5(1):7-12
The expression of the mouse α-amylase gene in the methylotrophic yeast,P. pastoris was investigated. The mouse α-amylase gene was inserted into the multi-cloning site of a Pichia expression vector, pPIC9,
yielding a new expression vector pME624. The plasmid pME624 was digested withSalI orBglII, and was introduced intoP. pastoris strain GS115 by the PEG1000 method. Fifty-three transformants were obtained by the transplacement of pME624 digested withSalI orBglII into theHIS
4 locus (38 of Mut+ clone) or into theAOX1 locus (45 of Muts clone). Southern blot was carried out in 11 transformants, which showed that the mouse α-amylase gene was integrated into
thePichia chromosome. When the second screening was performed in shaker culture, transformant G2 showed the highest α-amylase activity,
290 units/ml after 3-day culture, among 53 transformants. When this expression level of the mouse α-amylase gene is compared
with that in recombinantSaccharomyces cerevisiae harboring a plasmid encoding the same mouse α-amylase gene, the specific enzyme activity is eight fold higher than that of
the recombinantS. cerevisiae. 相似文献