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101.
Kensuke Nakata Yusuke Shigemiya 《Biological journal of the Linnean Society. Linnean Society of London》2015,116(4):954-963
Animal body coloration serves several functions such as thermoregulation, camouflage, aposematism, and intraspecific communication. In some orb‐web spiders, bright and conspicuous body colours are used to attract prey. On the other hand, there are other species whose body colour does not attract prey. Using a spider species showing individual body‐colour variation, the present study aimed to determine whether or not the variation in body colour shows a correlation with predation rates. We studied the orb‐web spider (Cyclosa argenteoalba) using both field observations and T‐maze experiments, in which the prey were exposed to differently coloured spiders. Cyclosa argenteoalba has silver‐ and black‐coloured areas on its dorsal abdomen, with the ratio of these two colours varying continuously among individuals. The bright and conspicuous silver area reflects ultraviolet light. Results of both field observations and colour choice experiments using Drosophila flies as prey showed that darker spiders have a greater chance of capturing prey than silver spiders. This indicates that body‐colour variation affects predation success among individuals and that the bright silver colour does not function to attract prey in C. argenteoalba. 相似文献
102.
103.
Multiplexin (Mp) is the Drosophila orthologue of vertebrate collagens XV and XVIII. Like them, Mp is widely distributed in the basement membranes of the developing embryos, including those of neuroblasts in the central and peripheral nervous systems, visceral muscles of the gut, and contractile cardioblasts. Here we report the identification of mutant larvae bearing piggyBac transposon insertions that exhibit decrease Mp production associated with abdominal cuticular and wing margin defects, malformation of sensory organs and impaired sensitivity to physical stimuli. Additional findings include the abnormal ultrastructure of fatbody associated with abnormal collagen IV deposition, and reduced Wingless deposition. Collectively, these findings are consistent with the notion that Mp is required for the proper formation and/or maintenance of basement membrane, and that Mp may be involved in establishing the Wingless signaling gradients in the Drosophila embryo. 相似文献
104.
Tanabe G Otani T Cong W Minematsu T Ninomiya K Yoshikawa M Muraoka O 《Bioorganic & medicinal chemistry letters》2011,21(10):3159-3162
Four analogs with 3′-O-alkyl groups (9a: CH3, 9b: C2H5, 9c: C13H27 or 9d: CH2Ph) instead of the 3′-O-sulfate anion in salacinol (1), a naturally occurring potent α-glucosidase inhibitor, were synthesized by the coupling reaction of 1,4-dideoxy-1,4-epithio-d-arabinitols (18a and 18b) with appropriate epoxides (10a-10d). These analogs showed equal or considerably higher inhibitory activity against rat small intestinal α-glucosidases than the original sulfate (1), and one of them (9d) was found more potent than currently used α-glucosidase inhibitors as antidiabetics. Thus, introduction of a hydrophobic moiety at the C3′ position of this new class of inhibitor was found beneficial for onset of stronger inhibition against these enzymes. 相似文献
105.
Kurata H Otsuki K Kusumi K Kurono M Terakado M Seko T Mizuno H Ono T Hagiya H Minami M Nakade S Habashita H 《Bioorganic & medicinal chemistry letters》2011,21(5):1390-1393
Structure-activity relationship of sphingosine-1-phosphate receptor agonist was examined. In terms of reducing the flexibility of molecule, hit compound 1 was modified to improve S1P1 agonistic activity as well as selectivity over S1P3 agonistic activity. Novel S1P agonists with cinnamyl scaffold or 1,2,5,6-tetrahydropyridine scaffold were identified. 相似文献
106.
Saito T Obitsu T Kondo T Matsui T Nagao Y Kusumi K Matsumura N Ueno S Kishi A Katsumata S Kagamiishi Y Nakai H Toda M 《Bioorganic & medicinal chemistry》2011,19(18):5432-5445
To identify an orally active corticotropin-releasing factor 1 receptor antagonist, a series of 6,7-dihydro-5H-cyclopenta[d]pyrazolo[1,5-a]pyrimidines and their derivatives were designed, synthesized and evaluated. An in vitro study followed by in vivo and pharmacokinetic studies of these heterotricyclic compounds led us to the discovery of an orally active CRF1 receptor antagonist. The results of a structure-activity relationship study are presented. 相似文献
107.
We report the synthesis and characterization of the arsonic acid-presenting superparamagnetic iron oxide (SPIO). We used arsonoacetic acid as the ligand for SPIOs in aqueous media. The surface modification of the SPIOs was accomplished via the ligand exchange from undecanoic acid to the carboxyl moiety of arsonoacetic acid. Consequently, the well-dispersed arsonic acid-presenting SPIOs in water were obtained. We found that the dispersion state of the arsonic acid-presenting SPIOs can be sharply regulated by pH changes in the biological significant region. The well dispersion state of the arsonic acid-presenting SPIOs can be maintained at the neutral pH region. In contrast, the arsonic acid-presenting SPIOs can sensitively form the aggregation below pH 6.1. Moreover, these dispersion states can be controlled reversibly by the pH alteration in the narrow region. 相似文献
108.
109.
Mehmet Zeynel Cilek Satoshi Hirohata Omer Faruk Hatipoglu Hiroko Ogawa Toru Miyoshi Junko Inagaki Takashi Ohtsuki Hiroshi Harada Shigeshi Kamikawa Shozo Kusachi Yoshifumi Ninomiya 《Cell biology international》2011,35(1):1-8
ADAMTS1 (a disintegrin and metalloproteinase with thrombospondin motifs 1) is an early immediate gene. We have previously reported that ADAMTS1 was strongly induced by hypoxia. In this study, we investigated whether ADAMTS1 promoter‐driven reporter signal is detectable by acute hypoxia. We constructed the GFP (green fluorescent protein) expression vector [AHR (acute hypoxia‐response sequence)‐GFP] under the control of ADAMTS1 promoter and compared it with the constitutive GFP‐expressing vector under the control of CMV (cytomegalovirus promoter‐GFP). We transduced AHR‐GFP and examined whether GFP signals can be detected under the acute hypoxia. When the human umbilical vein [HUVEC (human umbilical vein endothelial cells)] was transduced under normoxia, there were few GFP signals, while CMV‐GFP showed considerable GFP signals. When HUVEC was stimulated with hypoxia, GFP signals from AHR‐GFP gene were induced under hypoxic conditions. Notably, the GFP signals peaked at 3 h under hypoxia. In ischaemic hind limb model, transduced AHR‐GFP showed hypoxic induction of GFP signals. In summary, we have demonstrated that the AHR system induced the reporter gene expression by acute hypoxia, and its induction is transient. This is the first report showing the unique acute hypoxia‐activated gene expression system. 相似文献
110.
Kakazu E Ueno Y Kondo Y Inoue J Ninomiya M Kimura O Wakui Y Fukushima K Tamai K Shimosegawa T 《PloS one》2011,6(8):e23402