Sex allocation theory reveals a hidden cost of neonicotinoid exposure in a parasitoid wasp

P.R.W. was funded by the University of Stirling, C.V.B. and S.M.G. were funded by Nuffield Research Placements and N.C., J.G. and D.M.S. were funded by NERC (NE/J024481/1).Sex allocation theory has proved to be one the most successful theories in evolutionary ecology. However, its role in more applied aspects of ecology has been limited. Here we show how sex allocation theory helps uncover an otherwise hidden cost of neonicotinoid exposure in the parasitoid wasp Nasonia vitripennis. Female N. vitripennis allocate the sex of their offspring in line with Local Mate Competition (LMC) theory. Neonicotinoids are an economically important class of insecticides, but their deployment remains controversial, with evidence linking them to the decline of beneficial species. We demonstrate for the first time to our knowledge, that neonicotinoids disrupt the crucial reproductive behaviour of facultative sex allocation at sub-lethal, field-relevant doses in N. vitripennis. The quantitative predictions we can make from LMC theory show that females exposed to neonicotinoids are less able to allocate sex optimally and that this failure imposes a significant fitness cost. Our work highlights that understanding the ecological consequences of neonicotinoid deployment requires not just measures of mortality or even fecundity reduction among non-target species, but also measures that capture broader fitness costs, in this case offspring sex allocation. Our work also highlights new avenues for exploring how females obtain information when allocating sex under LMC.Publisher PDFPeer reviewe

Pathology of chronic achilles-tendon injuries in athletes

Overuse tendon conditions have traditionally been considered to result from an inflammatory process and were treated as such. Microscopic examination of abnormal Achilles-tendon tissues, however, reveals a non-inflammatory degenerative process. The histopathology found in surgical specimens in patients with chronic overuse Achilles tendinopathy and those with Achilles-tendon rupture are reviewed. Seminal studies suggest that so-called tendinitis is a rare condition that might occur occasionally in the Achilles tendon in association with a primary tendinosis. These data have clinical implications and require a review of the traditional classification of pathologies seen in tendon conditions, The authors recommend that nomenclature be based on histopathological findings rather than traditional hypothesis. <br /

Inducing cold-sensitivity in the frigophilic fly Drosophila montana by RNAi

The work was supported by CNPq (Fellowship to FMV) and a NERC Studentship to DJP.Cold acclimation is a critical physiological adaptation for coping with seasonal cold. By increasing their cold tolerance individuals can remain active for longer at the onset of winter and can recover more quickly from a cold shock. In insects, despite many physiological studies, little is known about the genetic basis of cold acclimation. Recently, transcriptomic analyses in Drosophila virilis and D.montana revealed candidate genes for cold acclimation by identifying genes upregulated during exposure to cold. Here, we test the role of myo-inositol-1-phosphate synthase (Inos), in cold tolerance in D. montana using an RNAi approach. D. montana has a circumpolar distribution and overwinters as an adult in northern latitudes with extreme cold. We assessed cold tolerance of dsRNA knock-down flies using two metrics: chill-coma recovery time (CCRT) and mortality rate after cold acclimation. Injection of dsRNAInos did not alter CCRT,either overall or in interaction with the cold treatment, however it did induced cold specific mortality, with high levels of mortality observed in injected flies acclimated at 5°C but not at 19°C. Overall, injection with dsRNAInos induced a temperature sensitive mortality rate of over 60% in this normally cold-tolerant species. qPCRanalysis confirmed that dsRNA injection successfully reduced gene expression of Inos. Thus, our results demonstrate the involvement of Inos in increasing cold tolerance in D. montana. The potential mechanisms involved by which Inos increases cold tolerance are also discussed.Publisher PDFPeer reviewe

International Olympic Committee Consensus Statement: Molecular Basis of Connective Tissue and Muscle Injuries in Sport

Tendon and ligament injures cause significant loss of performance in sport and decreased functional capacity in the workplace. Many of these injures remain difficult to treat, and many individuals have long-term pain and discomfort. Animal studies of growth factor and cell-based therapies have shown promising results, but these treatments also can be misused to enhance athletic performance. The International Olympic Committee (IOC) now has high-level scientific advisors who can advise the IOC as to the use and abuse of these technologies

Genomics of sex allocation in the parasitoid wasp Nasonia vitripennis

This research was funded by the Netherlands Genomics Initiative (Zenith 93511041) and the by the Natural Environment Research Council (NE/J024481/1).Background Whilst adaptive facultative sex allocation has been widely studied at the phenotypic level across a broad range of organisms, we still know remarkably little about its genetic architecture. Here, we explore the genome-wide basis of sex ratio variation in the parasitoid wasp Nasonia vitripennis, perhaps the best studied organism in terms of sex allocation, and well known for its response to local mate competition. Results We performed a genome-wide association study (GWAS) for single foundress sex ratios using iso-female lines derived from the recently developed outbred N. vitripennis laboratory strain HVRx. The iso-female lines capture a sample of the genetic variation in HVRx and we present them as the first iteration of the Nasonia vitripennis Genome Reference Panel (NVGRP 1.0). This panel provides an assessment of the standing genetic variation for sex ratio in the study population. Using the NVGRP, we discovered a cluster of 18 linked SNPs, encompassing 9 annotated loci associated with sex ratio variation. Furthermore, we found evidence that sex ratio has a shared genetic basis with clutch size on three different chromosomes. Conclusions Our approach provides a thorough description of the quantitative genetic basis of sex ratio variation in Nasonia at the genome level and reveals a number of inter-related candidate loci underlying sex allocation regulation.Publisher PDFPeer reviewe

THE FIRST VATICAN COUNCIL IN THE ZAGREB PRESS

U članku se donose informacije o pripremama i radu Prvoga vatikanskog koncila kako ih je prenosio zagrebački tisak. Istražuje se pisanje triju zagrebačkih tiskovina: Narodnih novina, Agramer Zeitunga i Zagrebačkoga katoličkog lista. Na osnovi vijesti iz navedenih izvora izlaže se početak, djelovanje i rad Prvoga vatikanskog koncila sve od njegova sazivanja 29. lipnja 1869. pa do prekida 1. rujna 1870., nakon čega je uslijedila okupacija Rima, što je učinila Kraljevina Italija, i prekid postojanja Papinske Države. Posebna pozornost posvećuje se koncilskom zasjedanjima na kojima je najaktualnija bila tema o papinoj nepogrešivosti. Na kraju rada u zaključnim razmatranjima donosi se analiza pisanja zagrebačkog tiska, iščitava se njihov stav o radu Koncila i proglašenoj dogmi, uočava se važnost tiska i javnosti u odnosu na zasjedanje Koncila. Opća konstatacija je da zagrebačke tiskovine nisu blagonaklono gledale na proglašenje dogme o papinoj nepogrešivosti, već su slijedile politiku vlastite države i stavove većine domaćeg episkopata.This article reveals information about preparations and work of the First Vatican Council as it was reported in the contemporary Zagreb press. Authors investigate writings in three newspapers from Zagreb: Narodne novine [National newspapers], Agramer Zeintug [Zagreb Newspapers] and Zagrebački katolički list [Zagreb Catholic Newspapers]. On the basis of the articles and information published in these newspapers, authors reconstruct opening and work of the First Vatican Council from its convocation (29th June 1869) until its downtime on 1st September 1870, which was followed by Italian occupation of Rome and abolishment of the Papal state. Authors give special attention to the Council’s sessions in which the most important topic was thesis about the papal impeccability. In the conclusion authors deliver an analysis of the texts published in the Zagreb press concerning the Council, in which they reveal press’ attitude and opinions about the work of the Council and the decreed dogma. Finally, authors have deduced that the press was quite important in making of the public opinion about the Council. Namely, it is quite clear that Zagreb press did not welcome decree of dogma on the papal impeccability, and in this manner press followed state policy and views of the majority of the local episcopacy

General contextual effects on neglected tropical disease risk in rural Kenya

The neglected tropical diseases (NTDs) are characterized by their tendency to cluster within groups of people, typically the poorest and most marginalized. Despite this, measures of clustering, such as within-group correlation or between-group heterogeneity, are rarely reported from community-based studies of NTD risk. We describe a general contextual analysis that uses multi-level models to partition and quantify variation in individual NTD risk at multiple grouping levels in rural Kenya. The importance of general contextual effects (GCE) in structuring variation in individual infection with Schistosoma mansoni, the soil-transmitted helminths, Taenia species, and Entamoeba histolytica/dispar was examined at the household-, sublocation- and constituency-levels using variance partition/intra-class correlation co-efficients and median odds ratios. These were compared with GCE for HIV, Plasmodium falciparum and Mycobacterium tuberculosis. The role of place of residence in shaping infection risk was further assessed using the spatial scan statistic. Individuals from the same household showed correlation in infection for all pathogens, and this was consistently highest for the gastrointestinal helminths. The lowest levels of household clustering were observed for E. histolytica/dispar, P. falciparum and M. tuberculosis. Substantial heterogeneity in individual infection risk was observed between sublocations for S. mansoni and Taenia solium cysticercosis and between constituencies for infection with S. mansoni, Trichuris trichiura and Ascaris lumbricoides. Large overlapping spatial clusters were detected for S. mansoni, T. trichiura, A. lumbricoides, and Taenia spp., which overlapped a large cluster of elevated HIV risk. Important place-based heterogeneities in infection risk exist in this community, and these GCEs are greater for the NTDs and HIV than for TB and malaria. Our findings suggest that broad-scale contextual drivers shape infectious disease risk in this population, but these effects operate at different grouping-levels for different pathogens. A general contextual analysis can provide a foundation for understanding the complex ecology of NTDs and contribute to the targeting of interventions

Yielding and irreversible deformation below the microscale: Surface effects and non-mean-field plastic avalanches

Nanoindentation techniques recently developed to measure the mechanical response of crystals under external loading conditions reveal new phenomena upon decreasing sample size below the microscale. At small length scales, material resistance to irreversible deformation depends on sample morphology. Here we study the mechanisms of yield and plastic flow in inherently small crystals under uniaxial compression. Discrete structural rearrangements emerge as series of abrupt discontinuities in stress-strain curves. We obtain the theoretical dependence of the yield stress on system size and geometry and elucidate the statistical properties of plastic deformation at such scales. Our results show that the absence of dislocation storage leads to crucial effects on the statistics of plastic events, ultimately affecting the universal scaling behavior observed at larger scales.Comment: Supporting Videos available at http://dx.plos.org/10.1371/journal.pone.002041

Oviposition but not sex allocation is associated with transcriptomic changes in females of the parasitoid wasp Nasonia vitripennis

This work was supported by Natural Environment Research Council (NERC) grant (NE/J024481/1). DMS was previously funded by a NERC Advanced Research Fellowship.Linking the evolution of the phenotype to the underlying genotype is a key aim of evolutionary genetics and is crucial to our understanding of how natural selection shapes a trait. Here we consider the genetic basis of sex allocation behaviour in the parasitoid wasp Nasonia vitripennis using a transcriptomics approach. Females allocate offspring sex in line with Local Mate Competition (LMC) theory. Female-biased sex ratios are produced when one or few females lay eggs on a patch. As the number of females contributing offspring to a patch increases, less female-biased sex ratios are favoured. We contrasted the transcriptomic responses of females as they oviposit under conditions known to influence sex allocation: foundress number (a social cue) and the state of the host (parasitised or not). We found, that when females encounter other females on a patch, or assess host quality with their ovipositors, the resulting changes in sex allocation is not associated with significant changes in whole-body gene expression. We also found that the gene expression changes produced by females, as they facultatively allocate sex in response to a host cue and a social cue, are very closely correlated. We expanded the list of candidate genes associated with oviposition behaviour in Nasonia, some of which may be involved in fundamental processes underlying the ability to facultatively allocate sex, including sperm storage and utilisation.Publisher PDFPeer reviewe