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991.
Simone Van Mourik 《Applied animal behaviour science》1985,14(3):275-287
A group of 50 hinds and four Rusa stags (Cervus rusa timorensis) were observed over a 2-year period under farming conditions. The aim of the study was to investigate the expression and relevance of dominance. A dominance order was calculated for the hinds. No significant influence of dominance value in relation to calving time, presence or absence of calf, mating time for the following season or the age of the hinds was found. The number of victories in comparison to the total number of interactions between stags was influenced by possession of a full set of antlers for young as well as old stags. However, the antler size or shape did not affect successful participation in the rutting activities of the stags. Hinds did not show a preference for stags based on antler appearance. It is recommended that stags should be velveted so as to minimize differences in antler shape and consequently to reduce dominance interactions between them. 相似文献
992.
Colonization of a novel depauperate habitat leads to trophic niche shifts in three desert lizard species 下载免费PDF全文
In a novel, depauperate ecosystem, colonizing species may experience changes in their trophic niche as a result of a new resource base and fewer competitors and predators. To examine trophic niche shifts of recent colonists, we focused on three ecologically and phylogenetically divergent lizard species that inhabit both the geologically distinctive depauperate habitat of White Sands and the surrounding Chihuahuan ‘dark soil’ desert in New Mexico. In White Sands the three species comprise the entire lizard community, whereas in the dark soils habitat, they constitute less than half of the lizard community abundance. As a result, we hypothesized that the three focal species would collectively represent a greater variety of trophic positions in the White Sands habitat than in the dark soils habitat. We hypothesized that the extent of shifts in each species’ trophic position would parallel diet and ecomorphology differences between habitats. To test these hypotheses, we combined analysis of lizard stomach contents with carbon and nitrogen stable isotopes in the context of previously published ecomorphology measurements. Stable isotope data indicated that as predicted, species were more different from one another in White Sands than in dark soils, suggesting community‐wide ecological release. Overall, all species were lower on the White Sands food chain; however, only one species decreased trophic level significantly, one increased trophic level variance, and one did not change significantly. Furthermore, stomach content data paralleled both stable isotope and ecomorphological data, showing different degrees of dietary overlap between habitats, depending on the species. That species’ differences in trophic ecology also correspond with ecomorphological differences suggests that these factors are either causally linked or collectively responding to similar ecological pressures, such as competition. By examining diet, trophic position, and ecomorphology of three colonist species, we demonstrate both species‐specific and community‐wide trophic differences in adjacent, but distinct habitats. 相似文献
993.
Rapid selection and characterization of Cry1F resistance in a Brazilian strain of fall armyworm 总被引:1,自引:0,他引:1 下载免费PDF全文
Natália A. Leite Simone M. Mendes Oscar F. Santos‐Amaya Chritiane A. Santos Thaís P. M. Teixeira Raul N. C. Guedes Eliseu J. G. Pereira 《Entomologia Experimentalis et Applicata》2016,158(3):236-247
Transgenic maize (Zea mays L., Poaceae) event TC1507, producing the Cry1F protein of Bacillus thuringiensis Berliner, has been used for management of the fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), in Brazil since 2009. A strain of S. frugiperda, obtained from field collections of larvae in TC1507 maize in Minas Gerais state in 2010, was selected in the laboratory for resistance to Cry1F using leaves of TC1507 maize in two selection regimes. Continuous exposure of larvae to Cry1F was more effective than exposure for 6, 8, and 10 days in the selection of resistant S. frugiperda individuals. With only four generations of laboratory selection, a strain with high levels of resistance to Cry1F was obtained, as indicated by the survival of insects reared on leaves of TC1507 maize plants and by the more than 300‐fold resistance level measured in bioassays with the purified Cry1F protein. Importantly, reciprocal crosses between control and the Cry1F‐selected strains revealed that the resistance is autosomal and incompletely recessive, and the response obtained in the backcross of the F1 generation with the resistant strain was consistent with simple monogenic inheritance. Additionally, there were no apparent fitness costs associated with resistance either for survival or larval growth on non‐Bt maize leaves. Our findings provide experimental evidence for rapid evolution of Cry1F resistance in S. frugiperda in the laboratory and further reinforce the potential of this species to evolve field resistance to the TC1507 maize as previously reported. The resistant strain isolated in this study provides an opportunity to estimate the resistance allele frequency in the field and to determine the biochemical and molecular basis of the resistance, which should provide further information to assist in the resistance management of S. frugiperda on transgenic maize producing B. thuringiensis proteins. 相似文献
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996.
Justin Warne Gareth Pryce Julia M. Hill Xiao Shi Felicia Lenner?s Fabiola Puentes Maarten Kip Laura Hilditch Paul Walker Michela I. Simone A. W. Edith Chan Greg J. Towers Alun R. Coker Michael R. Duchen Gyorgy Szabadkai David Baker David L. Selwood 《The Journal of biological chemistry》2016,291(9):4356-4373
The mitochondrial permeability transition pore is a recognized drug target for neurodegenerative conditions such as multiple sclerosis and for ischemia-reperfusion injury in the brain and heart. The peptidylprolyl isomerase, cyclophilin D (CypD, PPIF), is a positive regulator of the pore, and genetic down-regulation or knock-out improves outcomes in disease models. Current inhibitors of peptidylprolyl isomerases show no selectivity between the tightly conserved cyclophilin paralogs and exhibit significant off-target effects, immunosuppression, and toxicity. We therefore designed and synthesized a new mitochondrially targeted CypD inhibitor, JW47, using a quinolinium cation tethered to cyclosporine. X-ray analysis was used to validate the design concept, and biological evaluation revealed selective cellular inhibition of CypD and the permeability transition pore with reduced cellular toxicity compared with cyclosporine. In an experimental autoimmune encephalomyelitis disease model of neurodegeneration in multiple sclerosis, JW47 demonstrated significant protection of axons and improved motor assessments with minimal immunosuppression. These findings suggest that selective CypD inhibition may represent a viable therapeutic strategy for MS and identify quinolinium as a mitochondrial targeting group for in vivo use. 相似文献
997.
Crystal structure of the deglycating enzyme Amadoriase I in its free form and substrate‐bound complex 下载免费PDF全文
Andrea Dalle Vedove Anna Paola Lucarelli Simone Vesentini Emilio Parisini 《Proteins》2016,84(6):744-758
Amadoriases, also known as fructosyl amine oxidases (FAOX), are enzymes that catalyze the de‐glycosylation of fructosyl amino acids. As such, they are excellent candidates for the development of enzyme‐based diagnostic and therapeutic tools against age‐ and diabetes‐induced protein glycation. However, mostly because of the lack of a complete structural characterization of the different members of the family, the molecular bases of their substrate specificity have yet to be fully understood. The high resolution crystal structures of the free and the substrate‐bound form of Amadoriase I shown herein allow for the identification of key structural features that account for the diverse substrate specificity shown by this class of enzymes. This is of particular importance in the context of the rather limited and partially incomplete structural information that has so far been available in the literature on the members of the FAOX family. Moreover, using molecular dynamics simulations, we describe the tunnel conformation and the free energy profile experienced by the ligand in going from bulk water to the catalytic cavity, showing the presence of four gating helices/loops, followed by an “L‐shaped” narrow cavity. In summary, the tridimensional architecture of Amadoriase I presented herein provides a reference structural framework for the design of novel enzymes for diabetes monitoring and protein deglycation. Proteins 2016; 84:744–758. © 2016 Wiley Periodicals, Inc. 相似文献
998.
TDP‐43 loss of function inhibits endosomal trafficking and alters trophic signaling in neurons 下载免费PDF全文
Benjamin M Schwenk Hannelore Hartmann Alperen Serdaroglu Martin H Schludi Daniel Hornburg Felix Meissner Denise Orozco Alessio Colombo Sabina Tahirovic Meike Michaelsen Franziska Schreiber Simone Haupt Michael Peitz Oliver Brüstle Clemens Küpper Thomas Klopstock Markus Otto Albert C Ludolph Thomas Arzberger Peer‐Hendrik Kuhn Dieter Edbauer 《The EMBO journal》2016,35(21):2350-2370
999.
Grazia Luisi Adriano Mollica Simone Carradori Alessia Lenoci Anastasia De Luca 《Journal of enzyme inhibition and medicinal chemistry》2016,31(6):924-930
Context: The inhibition of glutathione S-transferase P1-1 (GSTP1-1) is a sound strategy to overcome drug resistance in oncology practice.Objective: The nitrobenzoxadiazolyl (NBD) S-conjugate of glutathione and the corresponding γ-oxa-glutamyl isostere (compounds 1 and 5, respectively) have been disclosed as GST inhibitors. The rationale of their design is discussed in juxtaposition to non-peptide NBD thioethers.Materials and methods: Synthesis of derivatives 1 and 5 and in vitro evaluation on human GSTP1-1 and M2-2 are reported.Results: Conjugates 1 and 5 were found to be low micromolar inhibitors of both isoforms. Furthermore, they display a threefold reduction in selectivity for GSTM2-2 over the P1-1 isozyme in comparison with the potent non-peptide inhibitor nitrobenzoxadiazolyl-thiohexanol (NBDHEX).Discussion and conclusions: Spectroscopic data are congruent with the formation of a stable sigma-complex between GSH and the inhibitors in the protein active site. Conjugate 5 is suitable for in vivo modulation of GST activity in cancer treatment. 相似文献
1000.
Experimental Manipulation of Food Accessibility Affects Conflict Management Behaviour in Ravens 下载免费PDF全文
Miriam Jennifer Sima Simone Pika Thomas Bugnyar 《Ethology : formerly Zeitschrift fur Tierpsychologie》2016,122(2):114-126
Conflict management strategies such as reconciliation and bystander affiliation have been described for a variety of species. A common determinant seems to be a ‘complex’ social life, with individuals relying on affiliate relationships or social bonds. Little is known, however, about the strategic and flexible use of conflict management skills in experimental settings in species other than primates. We here investigated conflict and post‐conflict behaviour of ravens by manipulating the accessibility of food and, thus, the likelihood of aggressive interactions while foraging. Specifically, we presented birds with a certain amount of highly preferred food that varied in the number of pieces (one piece, two pieces or, as a control, small pieces matching the number of participating birds) and observed their agonistic behaviour during feeding and their affiliative behaviour afterwards. The results showed that high levels of conflicts during feeding in the 1‐piece and 2‐piece conditions led to high levels of affiliation after feeding. Depending on the experimental condition, this effect is best explained (a) by the affiliative behaviour of former aggressors (1‐piece condition) and (b) by the affiliation directed to the receivers of aggression after feeding (2‐piece condition). Those dyads that engaged in allo‐preening after feeding also engaged in allo‐preening outside the experimental setting, suggesting that socially bonded individuals provided third‐party affiliation to victims of aggression. Moreover, socially bonded ravens fed close to each other in the experiment when food was clumped, indicating that they actively coordinated their behaviour when there was a high conflict potential. Taken together, these findings support the assumption that ravens use their social bonds to avoid conflicts by choosing with whom to feed, and to buffer effects of conflicts by engaging in third‐party affiliation as post‐conflict behaviour. 相似文献