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Do islands harbour less diverse disease communities than mainland? The island biogeography theory predicts more diverse communities on mainland than on islands due to more niches, more diverse habitats and availability of greater range of hosts. We compared bacteria prevalences of Campylobacter, Chlamydia and Salmonella in cloacal samples of a small shorebird, the Kentish plover (Charadrius alexandrinus) between two island populations of Macaronesia and two mainland locations in the Iberian Peninsula. Bacteria were found in all populations but, contrary to the expectations, prevalences did not differ between islands and mainland. Females had higher prevalences than males for Salmonella and when three bacteria genera were pooled together. Bacteria infection was unrelated to bird’s body condition but females from mainland were heavier than males and birds from mainland were heavier than those from islands. Abiotic variables consistent throughout breeding sites, like high salinity that is known to inhibit bacteria growth, could explain the lack of differences in the bacteria prevalence between areas. We argue about the possible drivers and implications of sex differences in bacteria prevalence in Kentish plovers

Transposable Elements (TEs) are ubiquitous genetic elements with the ability to move within a genome. TEs contribute to a large fraction of the repetitive elements of a genome, and because of their nature, they are not routinely analyzed in RNA-Seq gene expression studies. Amyotrophic Lateral Sclerosis (ALS) is a lethal neurodegenerative disease, and a well-accepted model for its study is the mouse harboring the human SOD1G93A mutant. In this model, landmark stages of the disease can be recapitulated at specific time points, making possible to understand changes in gene expression across time. While there are several works reporting TE activity in ALS models, they have not explored their activity through the disease progression. Moreover, they have done it at the expense of losing their locus of expression. Depending on their genomic location, TEs can regulate genes in cis and in trans, making locus-specific analysis of TEs of importance in order to understand their role in modulating gene expression. Particularly, the locus-specific role of TEs in ALS has not been fully elucidated. In this work, we analyzed publicly available RNA-Seq datasets of the SOD1G93A mouse model, to understand the locus-specific role of TEs. We show that TEs become up-regulated at the early stages of the disease, and via statistical associations, we speculate that they can regulate several genes, which in turn might be contributing to the genetic dysfunction observed in ALS.

Background Venturia inaequalis is an ascomycete fungus responsible for apple scab, a disease that has invaded almost all apple growing regions worldwide, with the corresponding adverse effects on apple production. Monitoring and predicting the effectiveness of intervention strategies require knowledge of the origin, introduction pathways, and population biology of pathogen populations. Analysis of the variation of genetic markers using the inferential framework of population genetics offers the potential to retrieve this information. Methodology/Principal Findings Here, we present a population genetic analysis of microsatellite variation in 1,273 strains of V. inaequalis representing 28 orchard samples from seven regions in five continents. Analysis of molecular variance revealed that most of the variation (88%) was distributed within localities, which is consistent with extensive historical migrations of the fungus among and within regions. Despite this shallow population structure, clustering analyses partitioned the data set into separate groups corresponding roughly to geography, indicating that each region hosts a distinct population of the fungus. Comparison of the levels of variability among populations, along with coalescent analyses of migration models and estimates of genetic distances, was consistent with a scenario in which the fungus emerged in Central Asia, where apple was domesticated, before its introduction into Europe and, more recently, into other continents with the expansion of apple growing. Across the novel range, levels of variability pointed to multiple introductions and all populations displayed signatures of significant post-introduction increases in population size. Most populations exhibited high genotypic diversity and random association of alleles across loci, indicating recombination both in native and introduced areas. Conclusions/Significance Venturia inaequalis is a model of invasive phytopathogenic fungus that has now reached the ultimate stage of the invasion process with a broad geographic distribution and well-established populations displaying high genetic variability, regular sexual reproduction, and demographic expansion., Contexte Venturia inaequalis est un champignon ascomycete responsable de la tavelure du pommier, une maladie qui a envahi presque toutes les régions du monde où le pommier est cultivé posant ainsi de graves problèmes en production. Prévenir et enrayer efficacement la réussite d’un tel succès invasif nécessite des connaissances approfondies sur l’origine, les voies d’introduction, la biologie et la génétique de ces populations invasives. En utilisant le potentiel d’inférence de la génétique des populations, l’analyse de la variation de marqueurs génétiques offre la possibilité d’accéder à ces informations. Méthodologie et Principaux résultats Ici nous présentons l’analyse de données microsatellites obtenues pour 1273 souches de V. inaequalis provenant de 28 vergers prélevées dans 7 régions sur les 5 continents. L’analyse de la variance moléculaire révèle que 88% de la variation se retrouve dans les vergers échantillonnés, ce qui est compatible avec d’importantes migrations historiques du champignon entre et à l’intérieur même des régions. Malgré cette très faible structuration des populations, les différentes analyses de clustering mettent en évidence un partage des populations en groupes séparés correspondant à leur origine géographique, montrant ainsi que chaque région héberge une population distincte du champignon. Ensemble, les résultats obtenus sur la comparaison du niveau de variabilité entre populations, les analyses de coalescence et les modèles de migration testés plaident en faveur d’un scénario dans lequel le champignon aurait émergé d’Asie Centrale, où le pommier a été domestiqué, avant d’être introduit en Europe puis plus récemment dans les autres continents suite à l’expansion de la culture du pommier. Les niveaux de variabilité indiquent que ces territoires ont subi des introductions multiples et que les populations portent toutes des signatures révélant de fortes expansions démographiques après leur introduction. Enfin, la forte diversité génotypique des populations et l’association aléatoire des allèles entre loci suggèrent que le champignon présente une reproduction sexuée régulière à la fois dans les régions où il a été introduit et dans sa région native. Conclusion et Portée. Venturia inaequalis est un modèle de champignons phytopathogène invasif qui a maintenant atteint le stade ultime du processus invasif, c’est à dire une très large distribution géographique par des populations bien établies montrant une grande diversité génétique, une reproduction sexuée régulière et une histoire d’expansion démographique.

Mitochondrial flux is currently accessible at low resolution. Here we introduce a genetically-encoded FRET sensor for pyruvate, and methods for quantitative measurement of pyruvate transport, pyruvate production and mitochondrial pyruvate consumption in intact individual cells at high temporal resolution. In HEK293 cells, neurons and astrocytes, mitochondrial pyruvate uptake was saturated at physiological levels, showing that the metabolic rate is determined by intrinsic properties of the organelle and not by substrate availability. The potential of the sensor was further demonstrated in neurons, where mitochondrial flux was found to rise by 300% within seconds of a calcium transient triggered by a short theta burst, while glucose levels remained unaltered. In contrast, astrocytic mitochondria were insensitive to a similar calcium transient elicited by extracellular ATP. We expect the improved resolution provided by the pyruvate sensor will be of practical interest for basic and applied researchers interested in mitochondrial function.

Novel solutions to conserve biodiversity whilst allowing for resource harvesting are urgently needed. In marine systems, Territorial User Rights for Fisheries (TURFs) are promoted to enable sustainable use of resources. We investigate the potential for synergies between nature-based tourism and TURFs on Chile's central coast. Of 135 recreational divers surveyed, 77% indicated that the fish species they preferred sighting were declining and 80% indicated that they would dive more often in TURFs, which have higher abundance of favoured species. Regression analysis shows that respondents that perceive that TURFs fulfil a conservation function are more willing to pay to dive in a TURF. However, respondents who understand the bureaucratic functioning of a TURF are less willing to pay, and there is diversity in how divers feel payments should be made. A participatory approach is required to navigate these complexities to achieve synergies between nature-based tourism and resource harvesting in TURFs., FONDECYT (project 11070034) Iniciativa Cientifica Milenio of the Ministerio de Economia, Fomento y Turismo grants RC130024 and NC 120086 and financiamiento Basal FB0002.