bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteasome inhibition suppresses essential immune functions of human CD4+ T cells
Authors: Berges Carsten , Haberstock Heinrich , Fuchs Dominik , Miltz Marion , Sadeghi Mahmoud , Opelz Gerhard , Daniel Volker , Naujokat Cord 
Published: May 2008

SummaryThe proteasome constitutes the central proteolytic component of the highly conserved ubiquitin–proteasome system, which is required for the maintenance and regulation of basic cellular processes, including differentiation, proliferation, cell cycling, gene transcription and apoptosis. Here we show that inhibition of proteasomal proteolytic activity by the proteasome inhibitors bortezomib and lactacystin suppresses essential immune functions of human CD4+ T cells activated by allogeneic dendritic cells (DCs). In activated CD4+ T cells, proteasome inhibition induces apoptosis accompanied by rapid accumulation and stabilization of the tumour suppressor protein p53. Activated CD4+ T cells surviving proteasome inhibition undergo inhibition of proliferation by induction of G1 phase cell‐cycle arrest. Induction of G1 arrest is accompanied by the accumulation of cyclin‐dependent kinase inhibitors p21WAF1/CIP1 and p27KIP1 and the disappearance of cyclin A, cyclin D2 and proliferating cell nuclear antigen, proteins known to regulate G1 to S phase cell‐cycle transitions. Expression of the activation‐associated cell surface receptors CD25, CD28, CD120b and CD134 as well as production of interferon‐γ (IFN‐γ), tumour necrosis factor‐α (TNF‐α), interleukin‐4 (IL‐4) and IL‐5 is suppressed in response to proteasome inhibition in CD4+ T cells activated by DCs. Expression of CD25, IFN‐γ, TNF‐α, IL‐4 and IL‐5 is known to be mediated by the transcriptional activity of nuclear factor of activated T cells (NFAT), and we show here that proteasome inhibition suppresses activation and nuclear translocation of NFATc2 in activated CD4+ T cells. Thus, the proteasome is required for essential immune functions of activated CD4+ T cells and can be defined as a molecular target for the suppression of deregulated and unwanted T‐cell‐mediated immune responses.
Enhanced immunostimulatory activity of oligodeoxynucleotides by Y‐shape formation
Authors: Nishikawa Makiya , Matono Mitsuhiro , Rattanakiat Sakulrat , Matsuoka Nao , Takakura Yoshinobu 
Published: May 2008

SummaryDNA containing unmethylated CpG dinucleotides (CpG DNA) is a potent activator of innate and acquired immune responses. Although the sequence‐specific immunostimulatory activity of CpG DNA has been extensively explored, little information is available about the importance of the stereochemical properties of CpG DNA. In this study, Y‐shaped oligodeoxynucleotides (Y‐ODNs) were prepared using three ODNs with the halves of each ODN being partially complementary to a half of the other two ODNs. Y‐ODN induced greater amounts of tumour necrosis factor‐α and interleukin‐6 from RAW264.7 macrophage‐like cells than did conventional single‐stranded ODN (ssODN) or double‐stranded ODN (dsODN). The Y‐ODN was less stable in serum than dsODN, but greater amounts of Y‐ODN were taken up by macrophage‐like cells compared with dsODN. A newly designed Y‐ODN containing three potent CpG motifs generated significantly higher levels of cytokines compared with dsODN containing the identical sequences. These results indicate that the Y‐shaped form of ODN is a novel, reproducible and reliable approach to enhancing the immunostimulatory activity of ODNs.
Covariation between intraspecific genetic diversity and species diversity within a plant functional group
Authors: He Tianhua , Lamont Byron B. , Krauss Siegfried L. , Enright Neal J. , Miller Ben P. 
Published: May 2008

Summary

Species diversity and genetic diversity are fundamental components of biodiversity. A primary goal of biodiversity studies is to explain the distribution of species and alleles in space and time. A new challenge is to cross discipline boundaries and explore the relationship between these two scales of diversity.
In the biodiverse northern sandplain shrublands of south‐western Australia, the woody shrub Banksia attenuata occurs on patchily distributed sand dunes, and coexists with B. hookeriana, B. menziesii, and two small tree species, Eucalyptus todtiana and Xylomelum angustifolium, which together comprise a plant functional group of large shrubs/small trees.
Genetic variation (alleles per locus and heterozygosity) between 736 B. attenuata individuals on 27 discrete dunes was assessed using 11 polymorphic microsatellite markers. For each dune, the physical properties of area and height, and species diversity (richness and evenness) of the functional group, were measured.
Synthesis. Genetic diversity of B. attenuata covaried positively with species diversity, which in turn covaried strongly with dune height rather than dune area. The positive relationship between species and genetic diversity demonstrated here supports the theory of common environmental, rather than neutral, processes acting directly or indirectly on both scales of diversity, and suggests the possibility of predicting one component of diversity on the basis of the other.
Genetic structure of natural Nasonia vitripennis populations: validating assumptions of sex‐ratio theory
Authors: GRILLENBERGER B. K. , KOEVOETS T. , BURTON‐CHELLEW M. N. , SYKES E. M. , SHUKER D. M. , VAN DE ZANDE L. , BIJLSMA R. , GADAU J. , BEUKEBOOM L. W. 
Published: May 2008

AbstractThe parasitic wasp Nasonia vitripennis has been used extensively in sex allocation research. Although laboratory experiments have largely confirmed predictions of local mate competition (LMC) theory, the underlying assumptions of LMC models have hardly been explored in nature. We genotyped over 3500 individuals from two distant locations (in the Netherlands and Germany) at four polymorphic microsatellite loci to validate key assumptions of LMC theory, in terms of both the original models and more recent extensions to them. We estimated the number of females contributing eggs to patches of hosts and the clutch sizes as well as sex ratios produced by individual foundresses. In addition, we evaluated the level of inbreeding and population differentiation. Foundress numbers ranged from 1 to 7 (average 3.0 ± 0.46 SE). Foundresses were randomly distributed across the patches and across hosts within patches, with few parasitizing more than one patch. Of the hosts, 40% were parasitized by more than one foundress. Clutch sizes of individual foundresses (average 9.99 ± 0.51 SE) varied considerably between hosts. The time period during which offspring continued to emerge from a patch or host correlated strongly with foundress number, indicating that sequential rather than simultaneous parasitism is the more common. Genetic differentiation at the regional level between Germany and the Netherlands, as estimated by Slatkin's private allele method (0.11) and Hedrick's corrected G′LT (0.23), indicates significant substructuring between regions. The level of population inbreeding for the two localities (FIL = 0.168) fitted the expectation based on the average foundress number per patch.
A novel role for oleosins in freezing tolerance of oilseeds in Arabidopsis thaliana
Authors: Shimada Takashi L. , Shimada Tomoo , Takahashi Hideyuki , Fukao Yoichiro , Hara‐Nishimura Ikuko 
Published: May 2008

SummaryOil bodies in seeds of higher plants are surrounded with oleosins. Here we demonstrate a novel role for oleosins in protecting oilseeds against freeze/thaw‐induced damage of their cells. We detected four oleosins in oil bodies isolated from seeds of Arabidopsis thaliana, and designated them OLE1, OLE2, OLE3 and OLE4 in decreasing order of abundance in the seeds. For reverse genetics, we isolated oleosin‐deficient mutants (ole1, ole2, ole3 and ole4) and generated three double mutants (ole1 ole2, ole1 ole3 and ole2 ole3). Electron microscopy showed an inverse relationship between oil body sizes and total oleosin levels. The double mutant ole1 ole2, which had the lowest levels of oleosins, had irregular enlarged oil‐containing structures throughout the seed cells. Germination rates were positively associated with oleosin levels, suggesting that defects in germination are related to the expansion of oil bodies due to oleosin deficiency. We found that freezing followed by imbibition at 4°C abolished seed germination of single mutants (ole1, ole2 and ole3), which germinated normally without freezing treatment. The treatment accelerated the fusion of oil bodies and the abnormal‐positioning and deformation of nuclei in ole1 seeds, which caused seed mortality. In contrast, ole1 seeds that had undergone freezing treatment germinated normally when incubated at 22°C instead of 4°C, because degradation of oils abolished the acceleration of fusion of oil bodies during imbibition. Taken together, our findings suggest that oleosins increase the viability of over‐wintering oilseeds by preventing abnormal fusion of oil bodies during imbibition in the spring.
Advances in the field of cannabinoid–opioid cross‐talk
Authors: Robledo Patricia , Berrendero Fernando , Ozaita Andrés , Maldonado Rafael 
Published: May 2008

ABSTRACTA remarkable amount of literature has been generated demonstrating the functional similarities between the endogenous opioid and cannabinoid systems. Anatomical, biochemical and molecular data support the existence of reciprocal interactions between these two systems related to several pharmacological responses including reward, cognitive effects, and the development of tolerance and dependence. However, the assessment of the bidirectionality of these effects has been difficult due to their variety and complexity. Reciprocal interactions have been well established for the development of physical dependence. Cross‐tolerance and cross‐sensitization, although not always bidirectional, are also supported by a number of evidence, while less data have been gathered regarding the relationship of these systems in cognition and emotion. Nevertheless, the most recent advances in cannabinoid–opioid cross‐modulation have been made in the area of drug craving and relapse processes. The present review is focused on the latest developments in the cannabinoid–opioid cross‐modulation of their behavioural effects and the possible neurobiological substrates involved.
Discrimination of Variation in a Male Signaling Trait Affects Detection Time in Visual Predators
Authors: Roberts J. Andrew , Uetz George W. 
Published: May 2008

AbstractIn many species, expression of elaborate male characteristics likely represents a balance between sexual selection and natural selection via predation, as male traits selected to elicit rapid detection or response on the part of females also increase detection by predators. Predation costs are frequently inferred, but the underlying mechanisms associated with specific traits have rarely been directly explored. Males of the wolf spiderSchizocosa ocreata(Araneae: Lycosidae) exhibit a sexually selected signaling trait (dark tufts of bristles) on their forelegs, and are sympatric with a number of visually hunting generalist predators, including cannibalistic conspecifics, that may impact spider survival. Here we use latency of orientation response of the American toad,Bufo americanus(Anura: Bufonidae), to video, ‘virtual’ courtingS. ocreatamale stimuli as an index of predator detection, and latency of orientation response of femaleS. ocreatato the same stimuli as an index of conspecific detection. When compared with stimuli representing the population average, elimination of the signal trait had no significant effect on predator detection but did increase latency to orient in conspecifics. Increasing the size of the signal trait had no effect on conspecific detection but did significantly reduce latency to orient for predatory toads. Results clearly indicate that for a courting male spider of a given size and vigor level, variation in the expression of a secondary sexual characteristic alone can incur differential direct costs and benefits by influencing latency of orientation to visual signals by predators and conspecifics.
Do Hosts Discriminate between Sexually Dichromatic Male and Female Brown‐headed Cowbirds?
Authors: Gill Sharon A. , Neudorf Diane L. H. , Sealy Spencer G. 
Published: May 2008

AbstractFemale brood parasites are recognized as threats to reproductive success by many host species. Male brood parasites may accompany females while they search for nests to parasitize and males depredate nests throughout the nesting cycle. Hence, selection may also favour recognition of males. We examined whether two common host species perceive male brown‐headed cowbirds (Molothrus ater) as brood parasites, as nest predators, or neither. We quantified visits of male cowbirds to nests of yellow warblers (Dendroica petechia) and red‐winged blackbirds (Ageliaus phoeniceus) to assess the frequency with which these host species interact with male cowbirds. Males were observed near nests during hosts’ laying and incubating stages, although less frequently than female cowbirds. No visits by cowbirds occurred while parents cared for nestlings. We then presented models of male and female cowbirds plus a non‐threatening control to yellow warblers and red‐winged blackbirds during laying and nestling periods. If hosts perceive males and females similarly, they should respond more intensely to the cowbird models during the laying period, when nests are most likely to be parasitized. Both species responded similarly to male and female cowbird models during laying, which suggests that hosts view cowbirds of both sexes as threats. The responses of yellow warblers with nestlings to male cowbirds were strongly influenced by the order of model presentation. Warblers first presented with the male cowbird gave much reduced anti‐parasite responses than those that first interacted with the female then the male cowbird. These results suggest that yellow warblers recognized male vs. female cowbirds, but that discrimination was not expressed during laying. By contrast, red‐winged blackbirds did not discriminate between male and female cowbirds at either nesting stage.
Inter‐Mount Social Interactions During Heterosexual and Homosexual Consortships in Japanese Macaques
Authors: Vasey Paul L. , VanderLaan Doug P. , Rains Derek , Duckworth Nadine , Kovacovsky Stefani D. 
Published: May 2008

AbstractIn this study, we examined whether female Japanese macaques (Macaca fuscata) exhibited male‐typical patterns of inter‐mountsocialbehaviour during homosexual consortships. Data were collected on heterosexual and homosexual consortships from a population of free‐ranging Japanese macaques in Arashiyama, Japan. Inter‐mount intervals were defined as the period between two consecutive mounts. A total of 3374 heterosexual inter‐mount intervals and 1412 homosexual inter‐mount intervals were analysed. We examined nine different categories of inter‐mount behaviour. Sex differences between heterosexually consorting males and females existed for three of the inter‐mount behaviours we examined (i.e. ventral‐to‐dorsal orientation, aggression directed toward third party individuals, tree‐shaking displays). The subordinate female partners in homosexually consorting pairs exhibited some sex‐atypical inter‐mount behaviours. This sex‐atypicality did not appear to reflect generalized developmental canalization in the direction of a male‐typical suite of behaviours. Rather, the observed behavioural sex‐atypicality could be best explained in terms of the unique alliance‐related dynamics that characterized homosexual consortships in Japanese macaques.
Does Competition for Clients Increase Service Quality in Cleaning Gobies?
Authors: Soares Marta C. , Bshary Redouan , Cardoso Sónia C. , Côté Isabelle M. 
Published: May 2008

AbstractIn a biological market, members of one trading class try to outbid each other to gain access to the most valuable partners. Competition within class can thus force individuals to trade goods or services more cheaply, ultimately resulting in conflict (e.g. cheating) over the value of commodities. Cleaning symbioses among fish appear to be good examples of biological markets. However, the existence and effect of outbidding competition among either types of traders (cleaners or clients) have never been tested. We examined whether increasing competition among cleaning gobies (Elacatinusspp.) for access to clients results in outbidding in the form of provision of a better cleaning service. On reefs where fish clients visited cleaning stations less frequently, and thus competition among cleaners was higher, cleaning gobies ingested fewer scales relative to the number of ingested parasites, i.e. they cleaned more honestly. This shift in cleaner behaviour towards greater honesty is consistent with a greater market value of access to clients in the face of competition among cleaners. However, this pattern could have also arisen as a result of differences in ectoparasite availability across reefs and therefore in value of the commodity offered by clients. Experimental manipulations will be required to determine whether cleaning service quality by cleaning gobies was enhanced solely because of competitive outbidding.
Innate and Learned Colour Preference in the Zebrafish,Danio rerio
Authors: Spence Rowena , Smith Carl 
Published: May 2008

AbstractReceiver biases towards specific sensory signals have been demonstrated in insects, birds and fish, both in the context of foraging and mate choice. In some cases, signals important in sexual selection appear to have evolved by exploiting a pre‐existing bias in the sensory system. For instance, female preferences for male nuptial colouration may have arisen from selection on foraging practices. Using the zebrafish (Danio rerio), a species in which red is not a factor in mate choice, we tested for a foraging bias towards the colour red. We further investigated the plasticity of foraging biases by raising groups of fish on diets consisting solely of red, blue, green or white food. When we subsequently tested their colour preferences in a foraging context, each group responded most strongly to red, irrespective of the colour of food with which they had been conditioned. We also detected a significant effect of conditioning on colour preferences; fish responded more strongly to the colour that matched diet colour than to other colours. The observed receiver bias towards red may have evolved as an adaptive preference for carotenoid compounds in their diet. While the bias to red appears to be innate, our results indicate that learning is also important in shaping foraging biases.
Efficiency of alternative MCMC strategies illustrated using the reaction norm model
Authors: Shariati M. , Sorensen D. 
Published: May 2008

SummaryThe Markov chain Monte Carlo (MCMC) strategy provides remarkable flexibility for fitting complex hierarchical models. However, when parameters are highly correlated in their posterior distributions and their number is large, a particular MCMC algorithm may perform poorly and the resulting inferences may be affected. The objective of this study was to compare the efficiency (in terms of the asymptotic variance of features of posterior distributions of chosen parameters, and in terms of computing cost) of six MCMC strategies to sample parameters using simulated data generated with a reaction norm model with unknown covariates as an example. The six strategies are single‐site Gibbs updates (SG), single‐site Gibbs sampler for updating transformed (a prioriindependent) additive genetic values (TSG), pairwise Gibbs updates (PG), blocked (all location parameters are updated jointly) Gibbs updates (BG), Langevin‐Hastings (LH) proposals, and finally Langevin‐Hastings proposals for updating transformed additive genetic values (TLH). The ranking of the methods in terms of asymptotic variance is affected by the degree of the correlation structure of the data and by the true values of the parameters, and no method comes out as an overall winner across all parameters. TSG and BG show very good performance in terms of asymptotic variance especially when the posterior correlation between genetic effects is high. In terms of computing cost, TSG performs best except for dispersion parameters in the low correlation scenario where SG was the best strategy. The two LH proposals could not compete with any of the Gibbs sampling algorithms. In this study it was not possible to find an MCMC strategy that performs optimally across the range of target distributions and across all possible values of parameters. However, when the posterior correlation between parameters is high, TSG, BG and even PG show better mixing than SG.
Development of multiplex PCR markers to distinguish evergreen and deciduous azaleas
Authors: Mizuta D. , Nakatsuka A. , Kobayashi N. 
Published: May 2008

AbstractWe successfully developed new PCR‐based markers for analysing the DNA inheritance patterns of vigorous inter‐subgeneric hybrids of azalea. The hybrids were between evergreen azaleas (Rhododendron nakaharae and its hybrids) and fragrant deciduous azaleas (Rhododendron arborescens and Rhododendron viscosum). We determined the sequence of the nuclear internal transcribed spacer (ITS) region in evergreen and deciduous azaleas, and found a deletion of five base pairs (bp) in evergreen azaleas compared with deciduous azaleas. Sequences for the chloroplast matK‐trnK region were obtained from GenBank. Primers for the multiplex PCRs were designed using these sequence data. In the multiplex PCR of the ITS region, evergreen azaleas showed a specific band of 140 bp and deciduous azaleas showed a specific band of 800 bp. In the multiplex PCR of the matK‐trnK region, evergreen azaleas showed a specific band of 560 bp and deciduous azaleas showed a specific band of 300 bp. These results indicate that multiplex PCR methods are useful to distinguish evergreen and deciduous azaleas easily and rapidly.
Top‐cross vs. poly‐cross as alternative to test‐cross for estimating the general combining ability in potato
Authors: Gopal J. , Kumar V. , Luthra S. K. 
Published: May 2008

AbstractTest‐crosses for estimating combining ability in potato although useful are difficult to make being labour intensive and time consuming, and due to the problem of sterility. The objective of the present study was to test methods for estimating general combining ability (GCA) of parents based on fewer matings. The GCA of 12 females estimated based on matings with specific single testers (top‐cross) and three types of bulk pollen (poly‐cross) were compared with those estimated by 72 (12 × 6) test‐crosses, using common testers in three types of matings. The study was conducted for 2 years at each of the two locations representing short‐days subtropical conditions in plains and long‐days temperate conditions in hills of India. Analysis of variance of test‐crosses showed that both general and specific combining ability effects were important for tuber yield, late blight resistance as well as general impression, the characters studied. Correlation coefficients among three types of matings showed that bulk pollen matings had poor effectiveness in predicting the GCA of the females, whereas matings with selected individual testers resulted in GCA estimates similar to those based on six testers. Thus use of top‐cross involving selected tester could substantially reduce the number of matings required for estimating the GCA. Among the six testers used, the tester CFK69.1 could estimate the GCA of the females with reasonably high accuracy both for tuber yield and general impression, and ‘Tobique’ for reaction to late blight.