bluuebunny/crossref_metadata_2025_split huggingface dataset:
The annexin gene family in the malaria mosquito Anopheles gambiae
Authors: Kotsyfakis M. , Vontas J. , Siden‐Kiamos I. , Louis C. 
Published: August 2005

AbstractAnnexins belong to a class of proteins that are known to bind to, and hold together structures such as membranes. Interestingly, Anopheles gambiae (and Drosophila melanogaster) annexins bind Plasmodium ookinetes in vitro. In the malaria mosquito three genes in two cytogenetic loci on chromosome arm 2R encode annexin homologues; their expression, monitored by quantitative real‐time PCR during mosquito development, as well as in various tissues, revealed little fluctuation in patterns of expression during all life stages. A different mode of transcription was observed for the three genes in the midgut in relation to the uptake of a blood meal. Immunohistochemical staining of midguts and ovaries with polyclonal anti‐annexin sera reveals that the Anopheles polypeptides are present in the epithelial cells of both tissues and associated with the plasma membrane.
Prediction of general mental ability based on neural oscillation measures of sleep
Authors: BÓDIZS RÓBERT , KIS TAMÁS , LÁZÁR ALPÁR SÁNDOR , HAVRÁN LINDA , RIGÓ PÉTER , CLEMENS ZSÓFIA , HALÁSZ PÉTER 
Published: August 2005

SummaryThe usual assessment of general mental ability (or intelligence) is based on performance attained in reasoning and problem‐solving tasks. Differences in general mental ability have been associated with event‐related neural activity patterns of the wakeful working brain or physical, chemical and electrical brain features measured during wakeful resting conditions. Recent evidences suggest that specific sleep electroencephalogram oscillations are related to wakeful cognitive performances. Our aim is to reveal the relationship between non‐rapid eye movement sleep‐specific oscillations (the slow oscillation, delta activity, slow and fast sleep spindle density, the grouping of slow and fast sleep spindles) and general mental ability assessed by the Raven Progressive Matrices Test (RPMT). The grouping of fast sleep spindles by the cortical slow oscillation in the left frontopolar derivation (Fp1) as well as the density of fast sleep spindles over the right frontal area (Fp2, F4), correlated positively with general mental ability. Data from those selected electrodes that showed the high correlations with general mental ability explained almost 70% of interindividual variance in RPMT scores. Results suggest that individual differences in general mental ability are reflected in fast sleep spindle‐related oscillatory activity measured over the frontal cortex.
Trypanosoma cruzi proline racemases are involved in parasite differentiation and infectivity
Authors: Chamond Nathalie , Goytia Maira , Coatnoan Nicolas , Barale Jean‐Christophe , Cosson Alain , Degrave Wim M. , Minoprio Paola 
Published: August 2005

SummaryPolyclonal lymphocyte activation is one of the major immunological disturbances observed after microbial infections and among the primary strategies used by the parasite Trypanosoma cruzi to avoid specific immune responses and ensure survival. T. cruzi is the insect‐transmitted protozoan responsible for Chagas’ disease, the third public health problem in Latin America. During infection of its mammalian host, the parasite secretes a proline racemase that contributes to parasite immune evasion by acting as a B‐cell mitogen. This enzyme is the first described eukaryotic amino acid racemase and is encoded by two paralogous genes per parasite haploid genome, TcPRACA and TcPRACB that give rise, respectively, to secreted and intracellular protein isoforms. While TcPRACB encodes an intracellular enzyme, analysis of TcPRACA paralogue revealed putative signals allowing the generation of an additional, non‐secreted isoform of proline racemase by an alternative trans‐splicing mechanism. Here, we demonstrate that overexpression of TcPRAC leads to an increase in parasite differentiation into infective forms and in its subsequent penetration into host cells. Furthermore, a critical impairment of parasite viability was observed in functional knock‐down parasites. These results strongly emphasize that TcPRAC is a potential target for drug design as well as for immunomodulation of parasite‐induced B‐cell polyclonal activation.
It works: combinatorial biosynthesis for generating novel glycosylated compounds
Authors: Luzhetskyy Andriy , Bechthold Andreas 
Published: August 2005

SummaryCombinatorial biosynthesis is a valuable method to generate novel glycosylated natural products. By coexpression of deoxysugar gene cassettes and genes from the staurosporine biosynthetic gene cluster it has now been applied to the generation of novel staurosporine derivatives. The work of Salas and co‐workers is highlighted in this article.
Cold‐ and salinity stress‐induced bipolar pea DNA helicase 47 is involved in protein synthesis and stimulated by phosphorylation with protein kinase C
Authors: Vashisht Ajay Amar , Pradhan Arun , Tuteja Renu , Tuteja Narendra 
Published: August 2005

SummaryHelicases are involved in the metabolism of nucleic acid; this is very sensitive to the abiotic stresses that reduce plant growth and productivity. However, the molecular targets responsible for this sensitivity have not been well studied. Here we report on the isolation and characterization of cold‐ and salinity stress‐induced pea DNA helicase 47 (PDH47). The transcript of PDH47 was induced in both shoots and roots under cold (4°C) and salinity (300 mm NaCl) stress, but there was no change in response to drought stress. Tissue‐specific differential regulation was observed under heat (37°C) stress. ABA treatment did not alter expression of PDH47 in shoots but induced its mRNA in roots, indicating a role for PDH47 in both the ABA‐independent and ABA‐dependent pathways in abiotic stress. The purified recombinant protein (47 kDa) contains ATP‐dependent DNA and RNA helicase and DNA‐dependent ATPase activities. With the help of photoaffinity labeling, PDH47 was labeled by [α‐32P]‐ATP. PDH47 is a unique bipolar helicase that contains both 3′ to 5′ and 5′ to 3′ directional helicase activities. Anti‐PDH47 antibodies immunodeplete the activities of PDH47 and inhibit in vitro translation of protein. Furthermore, the PDH47 protein showed upregulation of protein synthesis. The activities of PDH47 are stimulated after phosphorylation by protein kinase C at Ser and Thr residues. Western blot analysis and in vivo immunostaining, followed by confocal microscopy, showed PDH47 to be localized in both the nucleus and cytosol. The discovery of cold‐ and salinity stress‐induced DNA helicase should make an important contribution to a better understanding of DNA metabolism and stress signaling in plants. Its bipolar helicase activities may also be involved in distinct cellular processes in stressed conditions.
Combining probability from independent tests: the weighted Z‐method is superior to Fisher's approach
Authors: WHITLOCK M. C. 
Published: August 2005

AbstractThe most commonly used method in evolutionary biology for combining information across multiple tests of the same null hypothesis is Fisher's combined probability test. This note shows that an alternative method called the weighted Z‐test has more power and more precision than does Fisher's test. Furthermore, in contrast to some statements in the literature, the weighted Z‐method is superior to the unweighted Z‐transform approach. The results in this note show that, when combining P‐values from multiple tests of the same hypothesis, the weighted Z‐method should be preferred.
Paternal inheritance of the primary sex ratio in a copepod
Authors: VOORDOUW M. J. , ROBINSON H. E. , ANHOLT B. R. 
Published: August 2005

AbstractUniparentally inherited genetic elements are under strong selection to manipulate sex determination in their host and shift the host sex ratio towards the transmitting sex. For any sex‐ratio trait, lineage analysis and quantitative genetics are important tools for characterizing the mode of inheritance (biparental vs. maternal vs. paternal) thereby narrowing the field of possible sex‐determining mechanisms (e.g. polygenic, sex chromosomes with meiotic drive, cytoplasmic microorganisms). The primary sex ratio of the harpacticoid copepod,Tigriopus californicusis often male‐biased and is highly variable among full sib families. We found that this extra‐binomial variation for the primary sex ratio is paternally but not maternally transmitted inT. californicus. Paternal transmission of the primary sex ratio has been well documented in the haplo–diploid hymenoptera but is relatively rare in diplo–diploid organisms. If the sex‐ratio trait is paternally transmitted in other closely related harpacticoid copepods it would explain why male biased primary sex ratios are so common in this group.
The anther smut disease on Gypsophila repens: a case of parasite sub‐optimal performance following a recent host shift?
Authors: LÓPEZ‐VILLAVICENCIO M. , ENJALBERT J. , HOOD M. E. , SHYKOFF J. A. , RAQUIN C. , GIRAUD T. 
Published: August 2005

AbstractThe study of how parasites adapt to new hosts is of great importance for understanding the emergence of new diseases. Here, we report a study of the anther smut disease on Gypsophila repens (Caryophyllaceae). In contrast to what is usually found on other host species, infected natural populations of G. repens are extremely rare. Moreover, symptoms of diseased plants are incomplete and highly variable over the time. These results suggest that the fungus infecting G. repens is a case of a parasite not capable of exploiting its host optimally. Molecular analyses of Microbotryum violaceum strains infecting this and other Caryophyllaceae revealed that this sub‐optimal behaviour probably resulted from a recent host shift from the morphologically similar plant Petrorhagia saxifraga. With its exceptionally low virulence and prevalence, but apparent self‐sustainability, the disease on G. repens may thus represent an interesting case study for investigating the conditions leading to adaptation of parasites on new hosts.
The evolution of male genitalia: patterns of genetic variation and covariation in the genital sclerites of the dung beetle Onthophagus taurus
Authors: HOUSE C. M. , SIMMONS L. W. 
Published: August 2005

AbstractThree main hypotheses, have been invoked to explain divergent genital evolution, the lock and key, pleiotropy, and sexual selection hypotheses, each of which make different predictions about how genital traits are inherited. Here we used a half‐sib breeding design to examine the patterns of genetic variation and covariation between male genital sclerites, and their covariance with general body morphology in the dung beetle Onthophagus taurus. We found CVA's and CVP's were similar for both genital and general morphological traits and that CVR's were large for both trait types. We found that male genital sclerites were negatively genetically correlated with general morphological traits. Variation in male genital morphology has direct implications for a male's fertilization success and the resulting sexual selection acting on male genitalia is predicted to maintain high levels of additive genetic variance. Contrary to this prediction, we found that individual genital sclerites all had low levels of additive genetic variance and large maternal and environmental sources of variation. Our data suggest that the genital sclerites in O. taurus are not inherited independently but as a genetically integrated unit. More importantly, the way the different sclerites function to influence male fertilization success reflects this genetic integration. Even though levels of VA in individual genital sclerites may be low, there may still be sufficient VA in multivariate trait space for selection to generate evolutionary change in the overall morphology of male genitalia.
The social parasite waspPolistes atrimandibularisdoes not form host races
Authors: FANELLI D. , HENSHAW M. , CERVO R. , TURILLAZZI S. , QUELLER D. C. , STRASSMANN J. E. 
Published: August 2005

AbstractParasites that exploit the parental behaviour of several host species may be selected to form distinct host‐specific genetic lineages. This process is well documented in bird brood parasites, but not in insect social parasites.Polistes atrimandibularisis the only paper‐wasp social parasite known to exploit four host species. It does not form genetically distinct host races according to analyses based on microsatellite loci. Also, there were no size‐matching between parasites and host species. Instead,P. atrimandibularisqueens seemed to be successful as parasites in this population only when they originated from nests ofP. dominulus, the largest species. The other host species are a sink forP. atrimandibularissince adult females emerging from those nests appear too small to usurp colonies themselves. Traits that may helpP. atrimandibularisinfiltrate multiple species may include its nonaggressive usurpation tactics and its ability to acquire host cuticular hydrocarbon recognition labels.
On the worldwide spread of an insecticide resistance gene: a role for local selection
Authors: LABBE P. , LENORMAND T. , RAYMOND M. 
Published: August 2005

AbstractAdaptation occurs by gene replacement (or transient balanced polymorphism). Replacement may be caused by selection (local or global) and/or genetic drift among alleles. In addition, historical events may blur the respective effects of selection and drift during the course of replacement. We address the relative importance of these processes in the evolution of insecticide resistance genes in the mosquito Culex pipiens. The resistance allele, Ester2, has a broad geographic distribution compared to the other resistance alleles. To distinguish between the different processes explaining this distribution, we reviewed the literature and analysed updated data from the Montpellier area of southern France. Overall, our data indicate that Ester2 prevails over other Ester resistance alleles in moderately treated areas. Such conditions are common and favour the hypothesis of selection acting at a local level. This places an emphasis on the importance of ecological conditions during the evolution of resistance. Finally, we highlight that historical events have contributed to its spread in some areas.
Influence of genotype‐temperature interaction on pollen performance
Authors: HEDHLY A. , HORMAZA J. I. , HERRERO M. 
Published: August 2005

AbstractPollen competition and selection have significant evolutionary consequences, but very little is known about how they can be modulated. We have examined in cherry (Prunus avium L.) how pollen performance is affected by the genotype of the pollen and by the environmental conditions under which it grows, namely the pistilar tissue and temperature. The different pollen donor genotypes tested in this work differed in their behaviour both in vitro and in vivo and this behaviour was modulated depending on the female recipient they grew on. Furthermore, there was a significant temperature‐genotype interaction that affected the pollen tube population census that succeeded in reaching the base of the style. The combination of these three factors, while enabling a capacity of response to variations in environmental pressures, could maintain variability in pollen performance avoiding the fixation of the genes that control pollen tube growth rate.
Interspecific variation in the use of carotenoid‐based coloration in birds: diet, life history and phylogeny
Authors: OLSON V. A. , OWENS I. P. F. 
Published: August 2005

AbstractBirds show striking interspecific variation in their use of carotenoid‐based coloration. Theory predicts that the use of carotenoids for coloration is closely associated with the availability of carotenoids in the diet but, although this prediction has been supported in single‐species studies and those using small numbers of closely related species, there have been no broad‐scale quantitative tests of the link between carotenoid coloration and diet. Here we test for such a link using modern comparative methods, a database on 140 families of birds and two alternative avian phylogenies. We show that carotenoid pigmentation is more common in the bare parts (legs, bill and skin) than in plumage, and that yellow coloration is more common than red. We also show that there is no simple, general association between the availability of carotenoids in the diet and the overall use of carotenoid‐based coloration. However, when we look at plumage coloration separately from bare part coloration, we find there is a robust and significant association between diet and plumage coloration, but not between diet and bare part coloration. Similarly, when we look at yellow and red plumage colours separately, we find that the association between diet and coloration is typically stronger for red coloration than it is for yellow coloration. Finally, when we build multivariate models to explain variation in each type of carotenoid‐based coloration we find that a variety of life history and ecological factors are associated with different aspects of coloration, with dietary carotenoids only being a consistent significant factor in the case of variation in plumage. All of these results remain qualitatively unchanged irrespective of the phylogeny used in the analyses, although in some cases the precise life history and ecological variables included in the multivariate models do vary. Taken together, these results indicate that the predicted link between carotenoid coloration and diet is idiosyncratic rather than general, being strongest with respect to plumage colours and weakest for bare part coloration. We therefore suggest that, although the carotenoid‐based bird plumage may a good model for diet‐mediated signalling, the use of carotenoids in bare part pigmentation may have a very different functional basis and may be more strongly influenced by genetic and physiological mechanisms, which currently remain relatively understudied.
Games among cannibals: competition to cannibalize and parent‐offspring conflict lead to increased sibling cannibalism
Authors: PERRY J. C. , ROITBERG B. D. 
Published: August 2005

AbstractSibling cannibalism occurs in many species, yet understanding of sibling cannibalism as an adaptation currently lags behind understanding of other antagonistic interactions among siblings. Observed sibling cannibalism phenotypes likely reflect the interaction between competitive games among siblings and parent‐offspring conflict. Using a game‐theoretic approach, we derive optimal offspring cannibalism behaviour and parental modifiers that limit or facilitate cannibalism. The results are compared to contemporary frequency‐independent analysis. With the addition of game interactions among siblings or parent‐offspring co‐evolution, our model predicts increased cannibalism (compared to the frequency‐independent prediction), as offspring compete to eat siblings. When infertile eggs are present – strengthening competition – offspring risk eating viable siblings in order to gain access to infertile eggs, intensifying parent‐offspring conflict. We use the results to make new predictions about the occurrence of sibling cannibalism. Additionally, we demonstrate the utility of trophic egg laying as a maternal mechanism to promote egg eating.
Female common lizards (Lacerta vivipara) do not adjust their sex‐biased investment in relation to the adult sex ratio
Authors: LE GALLIARD J.‐F. , FITZE P. S. , COTE J. , MASSOT M. , CLOBERT J. 
Published: August 2005

AbstractSex allocation theory predicts that facultative maternal investment in the rare sex should be favoured by natural selection when breeders experience predictable variation in adult sex ratios (ASRs). We found significant spatial and predictable interannual changes in local ASRs within a natural population of the common lizard where the mean ASR is female‐biased, thus validating the key assumptions of adaptive sex ratio models. We tested for facultative maternal investment in the rare sex during and after an experimental perturbation of the ASR by creating populations with female‐biased or male‐biased ASR. Mothers did not adjust their clutch sex ratio during or after the ASR perturbation, but produced sons with a higher body condition in male‐biased populations. However, this differential sex allocation did not result in growth or survival differences in offspring. Our results thus contradict the predictions of adaptive models and challenge the idea that facultative investment in the rare sex might be a mechanism regulating the population sex ratio.
Local adaptation and population structure at a micro‐geographical scale of a fungal parasite on its host plant
Authors: CAPELLE J. , NEEMA C. 
Published: August 2005

AbstractLocal adaptation, which has been detected for several wild pathosystems is influenced by gene flow and recombination. In this study, we investigate local adaptation and population structure at a fine scale in wild populations of a plant‐pathogen fungus. We sampled hierarchically strains of Colletotrichum lindemuthianum in a wild population of its host. The analysis of AFLP patterns obtained for 86 strains indicated that: (i) many different haplotypes can be discriminated, although occurrence of recombination could not be shown; (ii) migration between adjacent plants seemed rare during the season; and (iii) neutral diversity is structured according to groups of plants and individual host plants. Furthermore, we tested for the occurrence of local adaptation using a cross‐inoculation experiment. Our results showed local adaptation at the scale of the individual host plant. These results indicate that fine‐scale dynamics has evolutionary consequences in this pathosystem.
Medicago – Sinorhizobium symbiotic specificity evolution and the geographic expansion of Medicago
Authors: BÉNA G. , LYET A. , HUGUET T. , OLIVIERI I. 
Published: August 2005

AbstractThe legume genus Medicago interacts with soil bacteria commonly referred to as rhizobia, in a nitrogen fixing symbiosis. We analysed the diversity of symbiotic association specificity among the two organisms, and its evolution in the plant genus. Nitrogen fixation tests and molecular phylogenetic reconstructions revealed that the genus Medicago includes more symbiotic specificity groups than previously suggested and that plant specificity is highly unstable and has repeatedly switched along the diversification of this genus. A phylogenetic analysis including geographical data shows that bacterial geographical diversity distribution has a strong influence on the geographic distribution of plant species and their ability to colonize new areas. Multiple other modifications of specificity occurred along the diversification of the genus, presumably due to selection for specialization to a single bacterial biovar. Codivergence between plants and bacteria may also have taken place.