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121.
As it walks, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) spins a trail of silk threads, that is followed by the predatory mite, Neoseiulus womersleyi Schicha (Acari: Phytoseiidae). Starved adult female N. womersleyi followed T. urticae trails laid down by five T. urticae females but did not follow a trail of one T. urticae female, suggesting that the amount of spun threads and their chemical components should correlate positively with the number
of T. urticae individuals. To examine whether chemical components of T. urticae trails are responsible for the predatory mite’s trail following, we collected separate T. urticae threads from the exuviae and eggs, and then washed the threads with methanol to separate chemical components from physical
attributes of the threads. Female N. womersleyi did not follow T. urticae trails that had been washed with methanol but contained physical residues, but they did follow the direction to which the
methanol extracts of the T. urticae trails was applied. These results suggest that the predatory mite follows chemical, not physical, attributes of T. urticae trails. 相似文献
122.
Okamoto T Yamada M Sekiya S Okuhara T Taguchi G Inatomi S Shimosaka M 《Bioscience, biotechnology, and biochemistry》2010,74(11):2327-2329
Agrobacterium tumefaciens was used to transform the vegetative dikaryotic mycelium of Flammulina velutipes using a hygromycin B resistance gene as selectable marker. The gene coding for urogen III methyltransferase (cob) was introduced into F. velutipes dikaryotic cells. The resulting transformant cells generated a bright red fluorescence, indicating that cob is promising as a reporter gene in F. velutipes. 相似文献
123.
Masaki Asada Tetsuo Obitsu Atsushi Kinoshita Yoshihiko Nakai Toshihiko Nagase Isamu Sugimoto Motoyuki Tanaka Hiroya Takizawa Ken Yoshikawa Kazutoyo Sato Masami Narita Shuichi Ohuchida Hisao Nakai Masaaki Toda 《Bioorganic & medicinal chemistry letters》2010,20(8):2639-2643
A series of novel N-acylsulfonamide analogs were synthesized and evaluated for their binding affinity and antagonist activity for the EP3 receptor subtype. Representative compounds were also evaluated for their inhibitory effect on PGE2-induced uterine contraction in pregnant rats. Among those tested, a series of N-acylbenzenesulfonamide analogs were found to be more potent than the corresponding carboxylic acid analogs in both the in vitro and in vivo evaluations. The structure activity relationships (SAR) are also discussed. 相似文献
124.
Masa-aki Yoshida Shuichi Shigeno Kazuhiko Tsuneki Hidetaka Furuya 《Evolution & development》2010,12(1):25-33
SUMMARY The highly specialized cephalopod cardiovascular system has long been considered a valuable model for understanding the evolution of circulatory systems. Despite the number of studies devoted to this topic, the developmental regulatory mechanisms remain largely unexplored. Here, we focus on the vascular endothelial growth factor receptor (VEGFR). This factor is known to mediate levels of endothelial growth factor that is involved in hematopoiesis and vasculogenesis including multichambered heart development in vertebrates. We found a squid VEGFR ortholog that is expressed in the developing blood vessels, notably in the sheet-like endothelial cells of the systemic and branchial hearts. The highly restricted localization of VEGFR in the vascular endothelial cells and its shared expression pattern in the developing hearts of cephalopods and vertebrates suggest a shared molecular signature of closed circulatory systems that has been independently elaborated during evolution. 相似文献
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As it is important to understand how protein conformational changes affect the separation performance in ion exchange chromatography (IEC), we investigated two model systems, unfolded proteins (lysozyme and bovine serum albumin) with urea and dithiothreitol, and PEGylated proteins (lysozyme attached with polyethyleneglycol molecular weight 5000). Linear gradient elution IEC experiments were carried out and the data were analysed by our model previously presented in order to obtain the binding site value B and the peak salt concentration I(R). Unfolded proteins (bovine serum albumin and lysozyme) with urea and dithiothreitol showed weaker retention and larger binding site values compared with the values for native proteins. Multiple PEGylated lysozyme peaks were separated, and eluted earlier than the native peak appeared. There is a good correlation between B and I(R) for PEGylated lysozymes. 相似文献
127.
Yoshida K Obata S Ono M Esaki M Maejima T Sawada H 《European journal of cell biology》2007,86(8):461-471
The 5F9A cell, which is a mesenchymal stem cell-like clone established from rat bone marrow substrate adherent cells, can differentiate into adipocytes and osteoblasts in vitro under the appropriate conditions. Multinucleated cells could be also induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in 5F9A cells. This effect was mediated by protein kinase C. Possible mechanisms of multinucleation by TPA were hypothesized to be either karyokinesis without cytokinesis or cell-cell fusion. By observation using time-lapse phase-contrast microscopy, we determined that the multinucleated cells were generated mainly by karyokinesis without cytokinesis. Cell fusion was studied using time-lapse photography, and confocal laser scanning microscopy using two differentially labeled cells. These techniques demonstrated that multinucleated 5F9A cells could be produced by cell fusion, albeit at a low frequency. We conclude that multinucleated 5F9A cells are formed primarily by karyokinesis without cytokinesis, although some cells are also formed by cell-cell fusion. 相似文献
128.
Reduced Contamination by the Fusarium Mycotoxin Zearalenone in Maize Kernels through Genetic Modification with a Detoxification Gene 总被引:4,自引:0,他引:4
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Tomoko Igawa Naoko Takahashi-Ando Noriyuki Ochiai Shuichi Ohsato Tsutomu Shimizu Toshiaki Kudo Isamu Yamaguchi Makoto Kimura 《Applied microbiology》2007,73(5):1622-1629
Maize is subject to ear rot caused by toxigenic Aspergillus and Fusarium species, resulting in contamination with aflatoxins, fumonisins, trichothecenes, and zearalenone (ZEN). The trichothecene group and ZEN mycotoxins are produced by the cereal pathogen Fusarium graminearum. A transgenic detoxification system for the elimination of ZEN was previously developed using an egfp::zhd101 gene (gfzhd101), encoding an enhanced green fluorescent protein fused to a ZEN-degrading enzyme. In this study, we produced a transgenic maize line expressing an intact copy of gfzhd101 and examined the feasibility of transgene-mediated detoxification in the kernels. ZEN-degrading activity has been detected in transgenic kernels during seed maturation (for a period of 6 weeks after pollination). The level of detoxification activity was unaltered after an additional storage period of 16 weeks at 6°C. When the seeds were artificially contaminated by immersion in a ZEN solution for 48 h at 28°C, the total amount of the mycotoxin in the transgenic seeds was uniformly reduced to less than 1/10 of that in the wild type. The ZEN in the transgenic maize kernels was also efficiently decontaminated under conditions of lower water activity (aw) and temperature; e.g., 16.9 μg of ZEN was removed per gram of seed within 48 h at an aw of 0.90 at 20°C. F. graminearum infection assays demonstrated an absence of ZEN in the transgenic maize seeds, while the mycotoxin accumulated in wild-type kernels under the same conditions. Transgene-mediated detoxification may offer simple solutions to the problems of mycotoxin contamination in maize. 相似文献
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