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841.
842.
A new catalyst, which is composed of nonnatural ribonucleotides, was synthesized by the in vitro selection method. Nonnatural RNAs that bound to N-methylmesoporphyrin were selected from a pool of random-sequence RNAs containing 2'-amino cytidine 5'-triphosphate (2'-amino CTP) instead of CTP. The selected RNAs not only bound to the ligand, N-methylmesoporphyrin (NMM), but also catalyzed metalation reaction of porphyrin. 相似文献
843.
Sjoerd J D Tjalsma Mayako Hori Yuko Sato Aurelie Bousard Akito Ohi Ana Cludia Raposo Julia Roensch Agnes Le Saux Jumpei Nogami Kazumitsu Maehara Tomoya Kujirai Tetsuya Handa Sandra BagsArnal Yasuyuki Ohkawa Hitoshi Kurumizaka Simo Teixeira da Rocha Jan J ylicz Hiroshi Kimura Edith Heard 《EMBO reports》2021,22(3)
During X chromosome inactivation (XCI), in female placental mammals, gene silencing is initiated by the Xist long non‐coding RNA. Xist accumulation at the X leads to enrichment of specific chromatin marks, including PRC2‐dependent H3K27me3 and SETD8‐dependent H4K20me1. However, the dynamics of this process in relation to Xist RNA accumulation remains unknown as is the involvement of H4K20me1 in initiating gene silencing. To follow XCI dynamics in living cells, we developed a genetically encoded, H3K27me3‐specific intracellular antibody or H3K27me3‐mintbody. By combining live‐cell imaging of H3K27me3, H4K20me1, the X chromosome and Xist RNA, with ChIP‐seq analysis we uncover concurrent accumulation of both marks during XCI, albeit with distinct genomic distributions. Furthermore, using a Xist B and C repeat mutant, which still shows gene silencing on the X but not H3K27me3 deposition, we also find a complete lack of H4K20me1 enrichment. This demonstrates that H4K20me1 is dispensable for the initiation of gene silencing, although it may have a role in the chromatin compaction that characterises facultative heterochromatin. 相似文献
844.
Toward cataloguing all rice genes: large-scale sequencing of randomly chosen rice cDNAs from a callus cDNA library 总被引:17,自引:0,他引:17
Takuji Sasaki Jianyu Song Yasunori Koga-Ban Eriko Matsui Fang Fang Hiromi Higo Hideki Nagasaki Maki Hori Mikiko Miya Eiko Murayama-Kayano Tomoko Takiguchi Akiko Takasuga Tomoya Niki Ken Ishimaru Hrioshi Ikeda Yoshihisa Yamamoto Yoshiyuki Mukai Isamu Ohta Nobuo Miyadera Ilkka Havukkala Yuzo Minobe 《The Plant journal : for cell and molecular biology》1994,6(4):615-624
845.
846.
We present a new temporal model of animal behavior based on the ethological idea that the internal states of the individual essentially determine the behavior. The internal states, however, are conditioned by the external stimuli. This model, including environmental and internal parameters, predicts a fractal property of the behavior, that is, an inverse power law distribution of the duration. Being consistent with the model, we have found a fractal property of feeding in Drosophila melanogaster: The dwelling time of starved flies on food showed a clear inverse power law distribution. The dependence of the fractal dimension on the intensity of food stimuli has been observed, and the predicted change into an exponential distribution was proved. 相似文献
847.
Shinsuke Nozaki Tomoya Takeda Takuya Kitaura Nobuyuki Takenaka Tohru Kataoka Takaya Satoh 《Cellular signalling》2013,25(6):1361-1371
The small GTPase Rac1 plays a pivotal role in insulin-stimulated glucose uptake in skeletal muscle, which is mediated by GLUT4 translocation to the plasma membrane. However, regulatory mechanisms for Rac1 and its role in the signaling pathway composed of phosphoinositide 3-kinase and the serine/threonine kinase Akt remain obscure. Here, we investigate the role of Akt in the regulation of Rac1 in myocytes. Insulin-induced, but not constitutively activated Rac1-induced, GLUT4 translocation was suppressed by Akt inhibitor IV. Insulin-induced Rac1 activation, on the other hand, was completely inhibited by this inhibitor. Constitutively activated phosphoinositide 3-kinase induced Rac1 activation and GLUT4 translocation. This GLUT4 translocation was almost completely suppressed by Rac1 knockdown. Furthermore, constitutively activated phosphoinositide 3-kinase-induced, but not constitutively activated Rac1-induced, GLUT4 translocation was suppressed by Akt2 knockdown. Finally, insulin-induced Rac1 activation was indeed inhibited by Akt2 knockdown. Together, these results reveal a novel regulatory mechanism involving Akt2 for insulin-dependent Rac1 activation. 相似文献
848.
Pioglitazone inhibits cancer cell growth through STAT3 inhibition and enhanced AIF expression via a PPARγ‐independent pathway
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849.
Lloyd W. Morrison Elizabeth A. Kawazoe Rodney Guerra Lawrence E. Gilbert 《Ecological Entomology》2000,25(4):433-444
1. Solenopsis (Hymenoptera: Formicidae) fire ants are host to Pseudacteon (Diptera: Phoridae) parasitoids. The activity of S. geminata (F.) hosts and relative abundance of Pseudacteon phorids, along with five environmental variables, were measured at weekly intervals over an 8‐month period at two sites. 2. Pseudacteon relative abundances often varied greatly from week to week, and were only weakly positively correlated with S. geminata activity. 3. A quadratic function of soil temperature was the single best predictor of ant activity at both sites, explaining 32 and 73% of the variation in ant activity. A linear function of soil moisture was the single best predictor of phorid relative abundance at one site (r2 = 0.23) whereas no measured variables were significant predictors of phorid relative abundance at the other site. 4. Interspecific interactions at 600 baits were monitored at a third site to document dominance hierarchies and determine whether the presence of Pseudacteon phorids mediated interspecific interactions in their host, S. geminata. 5. Solenopsis geminata was near the top of dominance hierarchies, which did not diverge greatly from a linear pattern. Three species (S. geminata, S. invicta Buren, and Crematogaster laeviuscula Mayr) won the majority of their interspecific interactions and appear to be co‐dominants at this microhabitat‐rich site. 6. Overall, the presence of phorids had no significant effect on the outcome of interspecific contests involving S. geminata and all other ant species grouped together. Phorids may have contributed to some of the S. geminata losses against other co‐dominant species. 相似文献
850.