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991.
Naoto Minamino Hiroshi Masuda Kenji Kangawa Hisayuki Matsuo 《Biochemical and biophysical research communications》1984,124(3):731-738
Neuromedin K and neuromedin L are novel mammalian tachykinins isolated from porcine spinal cord. We have developed a highly sensitive radioimmunoassay for neuromedin K. Since the radioimmunoassay for neuromedin K has significant crossreactivity with neuromedin L and substance P, we can simultaneously determine the tissue concentrations of neuromedin K, neuromedin L and substance P after separation of the tissue extracts by reverse phase high performance liquid chromatography. Substance P is found to be the most abundant mammalian tachykinin in every brain region. The ratio of the concentration of substance P to neuromedin K is small in cerebral cortex and large in medulla-pons, while that of substance P to neuromedin L is rather constant in a range of 2.0–2.5. In spinal cord, dorsal half contains more neuromedin K and L than ventral half as is the case with substance P. These results indicate that both neuromedin K and L are endogenous mammalian tachykinins with specific physiological functions. 相似文献
992.
Direct reciprocity, or repeated interaction, is a main mechanism to sustain cooperation under social dilemmas involving two individuals. For larger groups and networks, which are probably more relevant to understanding and engineering our society, experiments employing repeated multiplayer social dilemma games have suggested that humans often show conditional cooperation behavior and its moody variant. Mechanisms underlying these behaviors largely remain unclear. Here we provide a proximate account for this behavior by showing that individuals adopting a type of reinforcement learning, called aspiration learning, phenomenologically behave as conditional cooperator. By definition, individuals are satisfied if and only if the obtained payoff is larger than a fixed aspiration level. They reinforce actions that have resulted in satisfactory outcomes and anti-reinforce those yielding unsatisfactory outcomes. The results obtained in the present study are general in that they explain extant experimental results obtained for both so-called moody and non-moody conditional cooperation, prisoner’s dilemma and public goods games, and well-mixed groups and networks. Different from the previous theory, individuals are assumed to have no access to information about what other individuals are doing such that they cannot explicitly use conditional cooperation rules. In this sense, myopic aspiration learning in which the unconditional propensity of cooperation is modulated in every discrete time step explains conditional behavior of humans. Aspiration learners showing (moody) conditional cooperation obeyed a noisy GRIM-like strategy. This is different from the Pavlov, a reinforcement learning strategy promoting mutual cooperation in two-player situations. 相似文献
993.
Jun Xu Shuichi Nakamura Md. Shafiqul Islam Yijie Guo Kohei Ihara Rintaro Tomioka Mizuki Masuda Hiroshi Yoneyama Emiko Isogai 《PloS one》2016,11(4)
Mannose-binding lectin (MBL) is a key pattern recognition molecule in the lectin pathway of the complement system, an important component of innate immunity. MBL functions as an opsonin which enhances the sequential immune process such as phagocytosis. We here report an inhibitory effect of MBL on the motility of pathogenic bacteria, which occurs by affecting the energy source required for motility and the signaling pathway of chemotaxis. When Salmonella cells were treated with a physiological concentration of MBL, their motile fraction and free-swimming speed decreased. Rotation assays of a single flagellum showed that the flagellar rotation rate was significantly reduced by the addition of MBL. Measurements of the intracellular pH and membrane potential revealed that MBL affected a driving force for the Salmonella flagellum, the electrochemical potential difference of protons. We also found that MBL treatment increased the reversal frequency of Salmonella flagellar rotation, which interfered with the relative positive chemotaxis toward an attractive substrate. We thus propose that the motility inhibition effect of MBL may be secondarily involved in the attack against pathogens, potentially facilitating the primary role of MBL in the complement system. 相似文献
994.
Satoshi Yamamoto Kenji Minami Keiichi Fukaya Kohji Takahashi Hideki Sawada Hiroaki Murakami Satsuki Tsuji Hiroki Hashizume Shou Kubonaga Tomoya Horiuchi Masamichi Hongo Jo Nishida Yuta Okugawa Ayaka Fujiwara Miho Fukuda Shunsuke Hidaka Keita W. Suzuki Masaki Miya Hitoshi Araki Hiroki Yamanaka Atsushi Maruyama Kazushi Miyashita Reiji Masuda Toshifumi Minamoto Michio Kondoh 《PloS one》2016,11(4)
995.
Takuma Sato Alexei V. Abramov Evgeniy G. Raichev Pavel A. Kosintsev Risto Väinölä Takahiro Murakami Yayoi Kaneko Ryuichi Masuda 《Journal of Zoological Systematics and Evolutionary Research》2020,58(1):408-426
The least weasel (Mustela nivalis) is one of the most widely distributed carnivorans. While previous studies have identified distinct western and eastern mitochondrial DNA (mtDNA) lineages of the species in the western Palearctic, their broader distributions across the Palearctic have remained unknown. To address the broad-scale phylogeographical structure, we expanded the sampling to populations in Eastern Europe, the Urals, the Russian Far East, and Japan, and analyzed the mtDNA control region and cytochrome b, the final intron of the zinc finger protein on Y chromosome (ZFY), and the autosomal agouti signaling protein gene (ASIP). The mtDNA data analysis exposed the previous western lineage (Clade I) but poorly supported assemblage extending across Palearctic, whereas the previous eastern lineage (Clade II) was reconfirmed and limited in the south western part of the Palearctic. The ZFY phylogeny showed a distinctive split that corresponding to the mtDNA lineage split, although less phylogeographical structure was seen in the ASIP variation. Our data concur with the previous inference of the Black Sea–Caspian Sea area having an ancestral character. The Urals region harbored high mitochondrial diversity, with an estimated coalescent time of around 100,000 years, suggesting this could have been a cryptic refugium. Based on the coalescent-based demographic reconstructions, the expansion of Clade I across the Palearctic was remarkably rapid, while Clade II was relatively stable for a longer time. It seems that Clade II has maintained a constant population size in the temperate region, and the expansive Clade I represents adaptation to the cold regions. 相似文献
996.
Robert P. Smith Kenji Wellman Leila Haidari Hirohisa Masuda Myron L. Smith 《Genetics》2013,193(4):1175-1183
Type I ribonucleotide reductases (RNRs) are conserved across diverse taxa and are essential for the conversion of RNA into DNA precursors. In Neurospora crassa, the large subunit of RNR (UN-24) is unusual in that it also has a nonself recognition function, whereby coexpression of Oak Ridge (OR) and Panama (PA) alleles of un-24 in the same cell leads to growth inhibition and cell death. We show that coexpressing these incompatible alleles of un-24 in N. crassa results in a high molecular weight UN-24 protein complex. A 63-amino-acid portion of the C terminus was sufficient for un-24PA incompatibility activity. Redox active cysteines that are conserved in type I RNRs and essential for their catalytic function were found to be required for incompatibility activity of both UN-24OR and UN-24PA. Our results suggest a plausible model of un-24 incompatibility activity in which the formation of a complex between the incompatible RNR proteins is potentiated by intermolecular disulfide bond formation. 相似文献
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