TY - JOUR AB - Down syndrome cell adhesion molecule 1 (Dscam1) has widereaching and vital neuronal functions although the role it plays in insect and crustacean immunity is less well understood. In this study, we combine different approaches to understand the roles that Dscam1 plays in fitness-related contexts in two model insect species. Contrary to our expectations, we found no short-term modulation of Dscam1 gene expression after haemocoelic or oral bacterial exposure in Tribolium castaneum, or after haemocoelic bacterial exposure in Drosophila melanogaster. Furthermore, RNAi-mediated Dscam1 knockdown and subsequent bacterial exposure did not reduce T. castaneum survival. However, Dscam1 knockdown in larvae resulted in adult locomotion defects, as well as dramatically reduced fecundity in males and females. We suggest that Dscam1 does not always play a straightforward role in immunity, but strongly influences behaviour and fecundity. This study takes a step towards understanding more about the role of this intriguing gene from different phenotypic perspectives. AU - Peuß, Robert AU - Wensing, Kristina AU - Woestmann, Luisa AU - Eggert, Hendrik AU - Milutinovic, Barbara AU - Sroka, Marlene AU - Scharsack, Jörn AU - Kurtz, Joachim AU - Armitage, Sophie ID - 1255 IS - 4 JF - Royal Society Open Science TI - Down syndrome cell adhesion molecule 1: Testing for a role in insect immunity, behaviour and reproduction VL - 3 ER - TY - JOUR AU - Milutinovic, Barbara AU - Kurtz, Joachim ID - 1268 IS - 4 JF - Seminars in Immunology TI - Immune memory in invertebrates VL - 28 ER - TY - JOUR AB - The rare socially parasitic butterfly Maculinea alcon occurs in two forms, which are characteristic of hygric or xeric habitats and which exploit different host plants and host ants. The status of these two forms has been the subject of considerable controversy. Populations of the two forms are usually spatially distinct, but at Răscruci in Romania both forms occur on the same site (syntopically). We examined the genetic differentiation between the two forms using eight microsatellite markers, and compared with a nearby hygric site, Şardu. Our results showed that while the two forms are strongly differentiated at Răscruci, it is the xeric form there that is most similar to the hygric form at Şardu, and Bayesian clustering algorithms suggest that these two populations have exchanged genes relatively recently. We found strong evidence for population substructuring, caused by high within host ant nest relatedness, indicating very limited dispersal of most ovipositing females, but not association with particular host ant species. Our results are consistent with the results of larger scale phylogeographic studies that suggest that the two forms represent local ecotypes specialising on different host plants, each with a distinct flowering phenology, providing a temporal rather than spatial barrier to gene flow. AU - Tartally, András AU - Kelager, Andreas AU - Fürst, Matthias AU - Nash, David ID - 1431 IS - 3 JF - PeerJ TI - Host plant use drives genetic differentiation in syntopic populations of Maculinea alcon VL - 2016 ER - TY - GEN AB - Summary: Declining populations of bee pollinators are a cause of concern, with major repercussions for biodiversity loss and food security. RNA viruses associated with honeybees represent a potential threat to other insect pollinators, but the extent of this threat is poorly understood. This study aims to attain a detailed understanding of the current and ongoing risk of emerging infectious disease (EID) transmission between managed and wild pollinator species across a wide range of RNA viruses. Within a structured large-scale national survey across 26 independent sites, we quantify the prevalence and pathogen loads of multiple RNA viruses in co-occurring managed honeybee (Apis mellifera) and wild bumblebee (Bombus spp.) populations. We then construct models that compare virus prevalence between wild and managed pollinators. Multiple RNA viruses associated with honeybees are widespread in sympatric wild bumblebee populations. Virus prevalence in honeybees is a significant predictor of virus prevalence in bumblebees, but we remain cautious in speculating over the principle direction of pathogen transmission. We demonstrate species-specific differences in prevalence, indicating significant variation in disease susceptibility or tolerance. Pathogen loads within individual bumblebees may be high and in the case of at least one RNA virus, prevalence is higher in wild bumblebees than in managed honeybee populations. Our findings indicate widespread transmission of RNA viruses between managed and wild bee pollinators, pointing to an interconnected network of potential disease pressures within and among pollinator species. In the context of the biodiversity crisis, our study emphasizes the importance of targeting a wide range of pathogens and defining host associations when considering potential drivers of population decline. AU - Mcmahon, Dino AU - Fürst, Matthias AU - Caspar, Jesicca AU - Theodorou, Panagiotis AU - Brown, Mark AU - Paxton, Robert ID - 9720 TI - Data from: A sting in the spit: widespread cross-infection of multiple RNA viruses across wild and managed bees ER - TY - JOUR AB - Emerging infectious diseases (EIDs) have contributed significantly to the current biodiversity crisis, leading to widespread epidemics and population loss. Owing to genetic variation in pathogen virulence, a complete understanding of species decline requires the accurate identification and characterization of EIDs. We explore this issue in the Western honeybee, where increasing mortality of populations in the Northern Hemisphere has caused major concern. Specifically, we investigate the importance of genetic identity of the main suspect in mortality, deformed wing virus (DWV), in driving honeybee loss. Using laboratory experiments and a systematic field survey, we demonstrate that an emerging DWV genotype (DWV-B) is more virulent than the established DWV genotype (DWV-A) and is widespread in the landscape. Furthermore, we show in a simple model that colonies infected with DWV-B collapse sooner than colonies infected with DWV-A. We also identify potential for rapid DWV evolution by revealing extensive genome-wide recombination in vivo. The emergence of DWV-B in naive honeybee populations, including via recombination with DWV-A, could be of significant ecological and economic importance. Our findings emphasize that knowledge of pathogen genetic identity and diversity is critical to understanding drivers of species decline. AU - Mcmahon, Dino AU - Natsopoulou, Myrsini AU - Doublet, Vincent AU - Fürst, Matthias AU - Weging, Silvio AU - Brown, Mark AU - Gogol Döring, Andreas AU - Paxton, Robert ID - 1262 IS - 1833 JF - Proceedings of the Royal Society of London Series B Biological Sciences TI - Elevated virulence of an emerging viral genotype as a driver of honeybee loss VL - 283 ER -