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961.
Revollo JR Körner A Mills KF Satoh A Wang T Garten A Dasgupta B Sasaki Y Wolberger C Townsend RR Milbrandt J Kiess W Imai S 《Cell metabolism》2007,6(5):363-375
Intracellular nicotinamide phosphoribosyltransferase (iNampt) is an essential enzyme in the NAD biosynthetic pathway. An extracellular form of this protein (eNampt) has been reported to act as a cytokine named PBEF or an insulin-mimetic hormone named visfatin, but its physiological relevance remains controversial. Here we show that eNampt does not exert insulin-mimetic effects in vitro or in vivo but rather exhibits robust NAD biosynthetic activity. Haplodeficiency and chemical inhibition of Nampt cause defects in NAD biosynthesis and glucose-stimulated insulin secretion in pancreatic islets in vivo and in vitro. These defects are corrected by administration of nicotinamide mononucleotide (NMN), a product of the Nampt reaction. A high concentration of NMN is present in mouse plasma, and plasma eNampt and NMN levels are reduced in Nampt heterozygous females. Our results demonstrate that Nampt-mediated systemic NAD biosynthesis is critical for beta cell function, suggesting a vital framework for the regulation of glucose homeostasis. 相似文献
962.
Dale G. Nimmo Sarah Avitabile Sam C. Banks Rebecca Bliege Bird Kate Callister Michael F. Clarke Chris R. Dickman Tim S. Doherty Don A. Driscoll Aaron C. Greenville Angie Haslem Luke T. Kelly Sally A. Kenny Jos J. Lahoz‐Monfort Connie Lee Steven Leonard Harry Moore Thomas M. Newsome Catherine L. Parr Euan G. Ritchie Kathryn Schneider James M. Turner Simon Watson Martin Westbrooke Mike Wouters Matthew White Andrew F. Bennett 《Biological reviews of the Cambridge Philosophical Society》2019,94(3):981-998
Movement is a trait of fundamental importance in ecosystems subject to frequent disturbances, such as fire‐prone ecosystems. Despite this, the role of movement in facilitating responses to fire has received little attention. Herein, we consider how animal movement interacts with fire history to shape species distributions. We consider how fire affects movement between habitat patches of differing fire histories that occur across a range of spatial and temporal scales, from daily foraging bouts to infrequent dispersal events, and annual migrations. We review animal movements in response to the immediate and abrupt impacts of fire, and the longer‐term successional changes that fires set in train. We discuss how the novel threats of altered fire regimes, landscape fragmentation, and invasive species result in suboptimal movements that drive populations downwards. We then outline the types of data needed to study animal movements in relation to fire and novel threats, to hasten the integration of movement ecology and fire ecology. We conclude by outlining a research agenda for the integration of movement ecology and fire ecology by identifying key research questions that emerge from our synthesis of animal movements in fire‐prone ecosystems. 相似文献
963.
964.
Fangyuan Hua Robert J. Fletcher Jr Kathryn E. Sieving Robert M. Dorazio 《Proceedings. Biological sciences / The Royal Society》2013,280(1764)
Predation risk is widely hypothesized as an important force structuring communities, but this potential force is rarely tested experimentally, particularly in terrestrial vertebrate communities. How animals respond to predation risk is generally considered predictable from species life-history and natural-history traits, but rigorous tests of these predictions remain scarce. We report on a large-scale playback experiment with a forest bird community that addresses two questions: (i) does perceived predation risk shape the richness and composition of a breeding bird community? And (ii) can species life-history and natural-history traits predict prey community responses to different types of predation risk? On 9 ha plots, we manipulated cues of three avian predators that preferentially prey on either adult birds or offspring, or both, throughout the breeding season. We found that increased perception of predation risk led to generally negative responses in the abundance, occurrence and/or detection probability of most prey species, which in turn reduced the species richness and shifted the composition of the breeding bird community. Species-level responses were largely predicted from the key natural-history trait of body size, but we did not find support for the life-history theory prediction of the relationship between species'' slow/fast life-history strategy and their response to predation risk. 相似文献
965.
966.
967.
Kathryn B. Garber 《American journal of human genetics》2008,83(6):661-662
968.
969.
Jung-Kil Seo Jeana Stephenson J. Myron Crawford Kathryn L. Stone Edward J. Noga 《Marine biotechnology (New York, N.Y.)》2010,12(5):543-551
An antibacterial protein was purified from acidified gill extract of a bivalve mollusk, the American oyster (Crassostrea virginica). Protein isolation was best accomplished by briefly boiling the tissues in a weak acetic acid solution. Adding protease
inhibitors while boiling did not have a major effect on activity recovery. In contrast, use of only protease inhibitors (without
boiling) resulted in virtually no recovery of this activity. The amino acid sequence of this antibacterial protein was identified
as a histone H2B and was designated cvH2B. cvH2B had potent activity against gram-negative bacteria, including the human pathogens
Vibrio parahaemolyticus and Vibrio vulnificus, which commonly reside in oyster tissues. We estimated that the concentration of this protein was well within the concentration
that was inhibitory to these bacterial pathogens in vitro. This is the first report of the antimicrobial function of histone
H2B from any mollusk. 相似文献
970.
Colleen A. Burge Carolyn S. Friedman Rodman Getchell Marcia House Kevin D. Lafferty Laura D. Mydlarz Katherine C. Prager Kathryn P. Sutherland Tristan Renault Ikunari Kiryu Rebecca Vega-Thurber 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2016,371(1689)
Linking marine epizootics to a specific aetiology is notoriously difficult. Recent diagnostic successes show that marine disease diagnosis requires both modern, cutting-edge technology (e.g. metagenomics, quantitative real-time PCR) and more classic methods (e.g. transect surveys, histopathology and cell culture). Here, we discuss how this combination of traditional and modern approaches is necessary for rapid and accurate identification of marine diseases, and emphasize how sole reliance on any one technology or technique may lead disease investigations astray. We present diagnostic approaches at different scales, from the macro (environment, community, population and organismal scales) to the micro (tissue, organ, cell and genomic scales). We use disease case studies from a broad range of taxa to illustrate diagnostic successes from combining traditional and modern diagnostic methods. Finally, we recognize the need for increased capacity of centralized databases, networks, data repositories and contingency plans for diagnosis and management of marine disease. 相似文献