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Mirville Melanie O. Ridley Amanda R. Samedi J. P. M. Vecellio Veronica Ndagijimana Felix Stoinski Tara S. Grueter Cyril C. 《International journal of primatology》2020,41(2):382-400
International Journal of Primatology - Group-living animals face a number of threats from extragroup conspecifics: from individuals seeking mating opportunities to rival groups attempting to access... 相似文献
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Christina M. Ridley Karen E. Thur Jessica Shanahan Nagendra Babu Thillaiappan Ann Shen Karly Uhl Charlotte M. Walden Ahad A. Rahim Simon N. Waddington Frances M. Platt Aarnoud C. van der Spoel 《The Journal of biological chemistry》2013,288(36):26052-26066
β-Glucosidase 2 (GBA2) is an enzyme that cleaves the membrane lipid glucosylceramide into glucose and ceramide. The GBA2 gene is mutated in genetic neurological diseases (hereditary spastic paraplegia and cerebellar ataxia). Pharmacologically, GBA2 is reversibly inhibited by alkylated imino sugars that are in clinical use or are being developed for this purpose. We have addressed the ambiguity surrounding one of the defining characteristics of GBA2, which is its sensitivity to inhibition by conduritol B epoxide (CBE). We found that CBE inhibited GBA2, in vitro and in live cells, in a time-dependent fashion, which is typical for mechanism-based enzyme inactivators. Compared with the well characterized impact of CBE on the lysosomal glucosylceramide-degrading enzyme (glucocerebrosidase, GBA), CBE inactivated GBA2 less efficiently, due to a lower affinity for this enzyme (higher KI) and a lower rate of enzyme inactivation (kinact). In contrast to CBE, N-butyldeoxygalactonojirimycin exclusively inhibited GBA2. Accordingly, we propose to redefine GBA2 activity as the β-glucosidase that is sensitive to inhibition by N-butyldeoxygalactonojirimycin. Revised as such, GBA2 activity 1) was optimal at pH 5.5–6.0; 2) accounted for a much higher proportion of detergent-independent membrane-associated β-glucosidase activity; 3) was more variable among mouse tissues and neuroblastoma and monocyte cell lines; and 4) was more sensitive to inhibition by N-butyldeoxynojirimycin (miglustat, Zavesca®), in comparison with earlier studies. Our evaluation of GBA2 makes it possible to assess its activity more accurately, which will be helpful in analyzing its physiological roles and involvement in disease and in the pharmacological profiling of monosaccharide mimetics. 相似文献
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Vocal Cues to Identity: Pied Babblers Produce Individually Distinct But Not Stable Loud Calls 下载免费PDF全文
David J. Humphries Fiona M. Finch Matthew B. V. Bell Amanda R. Ridley 《Ethology : formerly Zeitschrift fur Tierpsychologie》2016,122(7):609-619
The ability to identify social partners can play a key role in the coordination of social behaviours in group‐living animals. Coordinating social behaviours over long distances becomes problematic, as cues to identity are often limited to one or two sensory modalities. This limitation can often select for strong individuality in those cues used for long‐distance communication. Pied babblers, Turdoides bicolor, produce a number of different types of ‘loud calls’ which are frequently used to signal to individuals beyond the range of visual or olfactory pathways of communication. Here, we show that three of these ‘loud call’ types, the v‐shaped chatter, the double note ascending chatter and the atonal chatter, are each individually distinct. We hypothesise that individuality in the three loud call types tested here may represent a possible pathway to social recognition in this species that may have important consequences for social interactions. However, we also found that the atonal chatter was unstable between years suggesting that this particular call type may not be a reliable long‐term indicator to identity which may affect long‐term recognition in this species. 相似文献
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Many studies of social species have reported variation in the anti-predator vigilance behaviour of foraging individuals depending on the presence and relative position of other group members. However, little attention has focused on how foragers assess these variables. It is commonly assumed that they do so visually, but many social species produce frequent calls while foraging, and these 'close' calls might provide valuable spatial information. Here, we show that foraging pied babblers (Turdoides bicolor) are less vigilant when in larger groups, in the centre of a group and in closer proximity to another group member. We then show that foragers are less vigilant during playbacks of close calling by more individuals and individuals on either side of them when compared with calls of fewer individuals and calls on one side of them. These results suggest that foragers can use vocal cues to gain information on group size and their spatial position within a group. Future studies of anti-predator vigilance should consider the relative importance of both visual and vocal monitoring of group members. 相似文献
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Humphreys MJ Moon RP Klinder A Fowler SD Rupp K Bur D Ridley RG Berry C 《FEBS letters》1999,463(1-2):43-48
The gene encoding an aspartic proteinase precursor (proplasmepsin) from the rodent malaria parasite Plasmodium berghei has been cloned. Recombinant P. berghei plasmepsin hydrolysed a synthetic peptide substrate and this cleavage was prevented by the general aspartic proteinase inhibitor, isovaleryl pepstatin and by Ro40-4388, a lead compound for the inhibition of plasmepsins from the human malaria parasite Plasmodium falciparum. Southern blotting detected only one proplasmepsin gene in P. berghei. Two plasmepsins have previously been reported in P. falciparum. Here, we describe two further proplasmepsin genes from this species. The suitability of P. berghei as a model for the in vivo evaluation of plasmepsin inhibitors is discussed. 相似文献
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Lawrence Livermore National Laboratory (LLNL) uses a cost-effective sampling (CES) methodology to evaluate and review ground water contaminant data and optimize the site's ground water monitoring plan. The CES methodology is part of LLNL's regulatory approved compliance monitoring plan (Lamarre et al., 1996). It allows LLNL to adjust the ground water sampling plan every quarter in response to changing conditions at the site. Since the use of the CES methodology has been approved by the appropriate regulatory agencies, such adjustments do not need additional regulatory approval. This permits LLNL to respond more quickly to changing conditions. The CES methodology bases the sampling frequency for each location on trend, variability, and magnitude statistics describing the contaminants at that location, and on the input of the technical staff (hydrologists, chemists, statisticians, and project leaders). After initial setup is complete, each application of CES takes only a few days for as many as 400 wells. Effective use of the CES methodology requires sufficient data, an understanding of contaminant transport at the site, and an adequate number of monitoring wells downgradient of the contamination. The initial implementation of CES at LLNL in 1992 produced a 40% reduction in the required number of annual routine ground water samples at LLNL. This has saved LLNL $390,000 annually in sampling, analysis, and data management costs. 相似文献