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International audience; Recent agricultural intensification threatens global biodiversity with amphibians being one of the most impacted groups. Because of their biphasic life cycle, amphibians are particularly vulnerable to habitat loss and fragmentation that often result in small, isolated populations and loss of genetic diversity. Here, we studied how landscape heterogeneity affects genetic diversity, gene flow and demographic parameters in the marbled newt, Triturus marmoratus, over a hedgerow network landscape in Western France. While the northern part of the study area consists of preserved hedged farm-land, the southern part was more profoundly converted for intensive arable crops production after WWII. Based on 67 sampled ponds and 10 microsatellite loci, we characterized regional population genetic structure and evaluated the correlation between landscape variables and (i) local genetic diversity using mixed models and (ii) genetic distance using multiple regression methods and commonality analysis. We identified a single genetic population characterized by a spatially heterogeneous isolation- by- distance pattern. Pond density in the surrounding landscape positively affected local genetic diversity while arable crop land cover negatively affected gene flow and connectivity. We used demographic inferences to quantitatively assess dif-ferences in effective population density and dispersal between the contrasted land-scapes characterizing the northern and southern parts of the study area. Altogether, results suggest recent land conversion affected T. marmoratus through reduction in both effective population density and dispersal due to habitat loss and reduced connectivity.

International audience; Linear transport infrastructure can impact wildlife directly or indirectly, and amphibians are particularly affected. In some cases, mitigation measures e such as tunnels below the linear transport infrastructure e are implemented, but an evaluation of their effectiveness is often lacking, especially for small animals such as amphibians. Few studies have focused on crossing behaviour in underpasses, yet this information may be crucial to improve mitigation measures. In this study, we conducted experiments in three tunnels below a high-speed railway with individually marked amphibians (great crested newt Triturus cristatus, marbled newt Triturus marmoratus, alpine newt Ichthyosaura alpestris, fire sala- mander Salamandra salamandra, spined toad Bufo spinosus, agile frog Rana dalmatina and edible/pool frog Pelophylax kl. esculentus/lessonae) which were released at the entrance of tunnels varying in length. Behaviours (e.g. completed crossing, U-turn, not moving, and stay) and crossing speed were recorded. R. dalmatina, S. salamandra and T. cristatus (but not B. spinosus) exhibited crossing rate differences between tunnels 21 m and 40 m in length. More individuals performed “complete crossing” through the shorter tunnel. The crossing speed of the S. salamandra and T. cristatus did not differ between the tunnels of different lengths. In a second experiment, we evaluated the effect of acoustic enrichment on the crossing behaviour of one frog and three newt species by broadcasting a soundtrack of mating calls of syntopic anuran species in the tunnels. Pelophylax kl exhibited a large in- crease in complete crossings and in speed. T. cristatus showed an increase in tunnel complete crossings (but not speed) in one of the acoustically enhanced tunnels. These results indicate that acoustic enrichment can improve the crossing of underpasses. This low cost and easily implementable method could help to inform the design of wildlife passages as mitigation measures for impacted amphibian populations, though more ex- periments on the effect of tunnel characteristics on amphibian behaviour would be valuable.

The maintenance of gene flow and colonization of new areas are influenced by an organism's movements in the landscape. Movement favors genetic mixing and limits inbreeding risk, hence decreasing the risk of extinction. Movement is a multifactorial process, however, and might be influenced by both individual traits and environmental factors. Studying the influence of individual characteristics and landscape features on movement is becoming an important challenge in evolutionary ecology and conservation biology, especially among threatened species such as amphibians. In a low-disperser species (Triturus marmoratus), we expected differences in movement ability to vary with individual traits, such as body length, as well as features of the landscape. On the basis of radiotracking surveys in both forests and agricultural lands, we revealed that landscape features and climatic conditions influenced the distances traveled by newts. Moreover, the individual traits, and particularly the body length and t...

International audience; The Montagu’s harrier (Circus pygargus) is a semi-colonial raptor species widely but patchily distributed across the Palearctic region with recorded cases of philopatry and presence of extra-pair copulation. In order to assess Montagu’s harrier spatial genetic structure and contemporary gene flow, we developed 16 new microsatellite markers using 454 pyrosequencing. Genotypes of 117 chicks sampled in a 200 × 300 km farmland area in Central Western France were analyzed to characterize genetic polymorphism at each locus and regional and fine-scale genetic structure. Fourteen markers were found polymorphic, with a number of alleles ranging from 3 to 11. The expected and observed heterozygosities ranged from 0.36 to 0.856 and from 0.35 to 0.868, respectively. A single genetic unit was found at the regional scale with higher genetic similarity observed at a small spatial scale (up to 10 km). Our results are consistent with overall large-scale juvenile and adult dispersal together with small-scale male philopatry. Cross-species amplification of this set of microsatellites makers has been successful in two closely related harrier species: the marsh harrier (Circus aeruginosus) and the Hen harrier (Circus cyaneus) for which 14 and 12 markers were polymorphic, respectively. These new microsatellite markers could be used to study the population genetic structure, contemporary gene flow and parentage analyses in these three species and to conduct microsatellite-based demographic inferences on the Montagu’s harrier.

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Amphibians are particularly sensitive to landscape fragmentation. Potential barriers between breeding sites can negatively infuence the dispersal of individuals and increase genetic structure between populations. In this study, we genotyped 10 microsatellites for 334 marbled newts (Triturus marmoratus) at 11 diferent locations in Western France. Samples were collected in diferent regions with contrasting agricultural landscapes (low and high proportion of arable land in the north and south, respectively). We found a strong genetic structure between the northern and southern sampling sites. Isolation by distance was recorded after 62km, but within the northern region, little or no genetic structure was detected over large distances (up to 114km). Genetic structure at shorter distance (43km) was found between sites situated in landscapes with larger amounts of arable lands. A signifcant positive relationship was found between the pairwise genetic distance (Fst) between sites and the amount of arable land together with the distance between sites. Our results suggest that the Loire River might act as a corridor for the marbled newt, while arable land might act as a barrier. Finally, although a large city is located between sampling sites, no efect was detected on population structure.

Preserving amphibian genetic diversity through ecological restoration and conservation actions is a major challenge since their populations are declining worldwide. We studied the genetic diversity and spatial genetic structure of the palmate newt (Lissotriton helveticus) 2 years after the restoration of a pond network in northwestern France with the aim of reconstructing fine-scale genetic structure and patterns of colonization. We sampled newts from 29 forest ponds including both restored and non-degraded reference ponds, and genotyped 391 individuals at 12 microsatellite loci. We used two Bayesian clustering methods to spatially delineate genetic clusters, and we also detected potential recent migrants within the network. All ponds showed low levels of observed heterozygosity (Ho = 0.534) and a mean F IS of 0.251, possibly indicating a Wahlund or bottleneck effect. Pairwise F ST suggested limited evidence of genetic differentiation among ponds. Within the pond network, we identified 3 to 4 genetic clusters. Combined with the detection of migrants, the results suggest an increase in gene flow within the restored pond network and that a high number of migrants came from the reference ponds. Our findings indicate an unexpected high dispersal ability for this small-bodied species. Overall, the absence of population structure represents a positive beginning for the restoration project. It also emphasizes the importance of spatial design in restoring a pond network and that such genetic data and methods should be used to monitor amphibians in restored habitats.

The physiological mechanisms underlying the ‘cost of reproduction’ remain under debate, though oxidative stress has emerged as a potential candidate. The ‘oxidative cost of reproduction’ has received considerable attention with regards to food and antioxidant availability, however the limitation of water availability has thus far been neglected. In this study we experimentally examined the combined effect of pregnancy and water-deprivation on oxidative status in a viviparous snake (Vipera aspis), a species naturally exposed to periods of water and food deprivation. We predicted a cumulative effect of pregnancy and dehydration on oxidative stress levels. Our results support the occurrence of an oxidative cost of reproduction since we found higher oxidative damage levels in pregnant females than in non-reproductive individuals, despite an up-regulation of antioxidant defences. Surprisingly, water-deprivation was associated with an up-regulation of antioxidant defences, and did not increase oxidative damage, either alone or in combination with reproduction.

αβ T-cell lines specific for sulfatide, an abundant myelin glycosphingolipid presented by various CD1 molecules, have been previously derived from PBMCs of patients with demyelinating diseases such as multiple sclerosis (MS) but also from healthy subjects. Using an unbiased tetramer-based MACS enrichment method to enrich for rare antigen-specific cells, we confirmed the presence of CD1d-sulfatide-specific T cells in all healthy individuals examined. Surprisingly, the great majority of fresh sulfatide-specific T cells belonged to the γδ lineage. Furthermore, these cells used the Vδ1 TCR variable segment, which is uncommon in the blood but predominates in tissues such as the gut and specifically accumulates in MS lesions. Recombinant Vδ1 TCRs from different individuals were shown to bind recombinant CD1d-sulfatide complexes in a sulfatide-specific manner. These results provide the first direct demonstration of MHC-like-restricted, antigen-specific recognition by γδ TCRs. Together with previous reports, they support the notion that human Vδ1 T cells are enriched in CD1-specific T cells and suggest that the Vδ1 T-cell population that accumulates in MS lesions might be enriched in CD1-sulfatide-specific cells.

Rare CD1d-α-galactosylceramide–specific T cells that do not express the invariant Vα24 chain of human NKT cells were recently identified after expansion in vitro with the lipid Ag, but their phenotype and frequency in vivo and lineage relationship with NKT cells could not be elucidated. By using a CD1d tetramer-based method to enrich these cells from fresh peripheral blood, we demonstrated their naive-like CD62LhighCD45RO−CD4+ phenotype and relatively high frequency of ∼10−5 in several healthy individuals. Notably, these cells expressed the NKT lineage-specific transcription promyelocytic leukemia zinc finger (PLZF), indicating a developmental relationship with NKT cells and ruling out the possibility that they were conventional MHC-restricted T cells cross-reacting against CD1d-α-galactosylceramide. Although PLZF is known to direct the effector program of NKT cells, we show in this study that the naive-like cells expressed it at a significantly lower amount than NKT cells. Further, we present mouse studies demonstrating a sharp PLZF expression threshold requirement for induction of the effector phenotype. These findings directly demonstrate in vivo the existence of naive-like CD1d-restricted human T cells marked by intermediate levels of PLZF.

Invasive species represent a major threat to biodiversity, and the understanding of their population genetics is one of the most important goals in conservation biology. Recently, it has been proposed that methods using molecular tools could help define efficient eradication strategies and should be a preliminary step in the management process. The American mink was introduced in Europe for fur farming purposes in the 1920s, and, due to escapees, several feral populations have been mentioned in the last decades. In France, feral mink have been observed since the 1970s, and the largest population, located in Brittany, is considered to be still expanding. We investigated the genetic variability and population structure of 149 feral mink and 21 farmed mink from this area using six microsatellite loci. Our results showed three genetically distinct population units at the regional scale. A pattern of isolation by distance was observed for the whole sample. In our case we explain this pattern by recent admixture of the three genetic units. Our findings suggest that populations have recently met and started to homogenise.

Triturus marmoratus is distributed throughout central, western and southern France as well as in a large portion of northern Iberia. Despite being categorized as of least concern by the IUCN, it is protected by the Annex IV of the EU Habitats Directive and the Annex III of the Bern Convention (Arntzen et al. 2009). As most amphibians, T. marmoratus is particularly sensitive to habitat loss and landscape fragmentation (Cushman 2006). Maintaining connectivity is therefore critical to ensure genetic diversity and sustainable populations. A good knowledge of the population genetic structure is necessary. Microsatellites are among the most commonly used genetic markers in numerous field of research (DeFaveri et al. 2013) and can be used in landscape genetics to assess population structure and quantify gene flow. Thus it can provide useful information for applied conservation ecology (Emel and Storfer 2015). Total genomic DNA from epithelial cells obtained from buccal swab and from tissue muscle of 15 marbled newts was isolated using the DNeasy Blood and Tissue kit (Qiagen, Valencia, USA) pooled in equal quantities, and 1 μg of the pooled DNA was used for the development of microsatellites libraries through 454 GS-FLX Titanium pyrosequencing of enriched DNA libraries as described in Malausa et al. (2011). Briefly, total DNAwas mechanically fragmented, ligated to standard adapters, enriched for AG, AC, AAC, AAG, AGG, ACG, ACAT and ATCT repeated motifs, and amplified by PCR. The purified products were then sequenced on a GsFLX PTP (Roche, Basel, Switzerland) following the manufacturer’s instructions. One hundred and seventythree microsatellite sequences were identified. From these, all sequences with an important number of repeats (as they have better chances to be polymorphic) and a size greater than 100 bp were selected. These resulted in the selection of

Pemphigus is a severe blistering condition of the skin and mucosa caused by autoantibodies directed against desmogleins, which are a type of keratinocyte adhesion protein. B cell depletion by rituximab has short-term efficacy against pemphigus. We aimed to assess the long-term course of pemphigus patients after B cell depletion and to understand the immunological mechanisms that mediate long-lasting remissions. We evaluated the clinical course of 22 pemphigus patients treated with rituximab after a 79-month median follow-up and compared the anti-desmoglein B cell response and B and T lymphocyte subpopulations and repertoire between patients who achieved complete remission (CR) and those who had incomplete remission (IR). Thirteen patients (59%) experienced CR during the study, including 10 patients off treatment and 3 patients with prednisone doses

Octopamine (OA) is an important neuroactive substance that modulates several physiological functions and behaviors of various invertebrate species. This biogenic monoamine, structurally related to noradrenaline, acts as a neurotransmitter, a neuromodulator, or a neurohormone in insects. The tyramine β-hydroxylase (TBH) catalyzes the last step in OA biosynthesis and thus plays a key role in the regulation of synthesis and secretion of OA in neurons. The aim of this study was to characterize TBH in the cockroach Periplaneta americana and to get a better understanding of its regulation under stress conditions in this insect. First of all, five full-length cDNAs encoding TBH isoforms were cloned from the nerve cord of the physiological model P. americana. PaTBH transcripts were found mainly expressed in nervous tissues and in octopaminergic dorsal unpaired median neurons. In addition, a new ELISA assay was developed so as to allow determination of both OA level and TBH activity in stressed cockroaches. Mechanical stressful stimulation led to a significant increase in TBH activity after 1 and 24 h, with a higher induction after 1 h than after 24 h. Thus, TBH could be considered as a promising biomarker of stress in insects rather than OA.

International audience; Genetic data are increasingly used in landscape ecology for the indirect assessment of functional connectivity, that is, the permeability of landscape to movements of organ- isms. Among available tools, matrix correlation analyses (e.g. Mantel tests or mixed models) are commonly used to test for the relationship between pairwise genetic dis- tances and movement costs incurred by dispersing individuals. When organisms are spatially clustered, a population-based sampling scheme (PSS) is usually performed, so that a large number of genotypes can be used to compute pairwise genetic distances on the basis of allelic frequencies. Because of financial constraints, this kind of sam- pling scheme implies a drastic reduction in the number of sampled aggregates, thereby reducing sampling coverage at the landscape level. We used matrix correlation analy- ses on simulated and empirical genetic data sets to investigate the efficiency of an individual-based sampling scheme (ISS) in detecting isolation-by-distance and isola- tion-by-barrier patterns. Provided that pseudo-replication issues are taken into account (e.g. through restricted permutations in Mantel tests), we showed that the use of inter- individual measures of genotypic dissimilarity may efficiently replace interpopulation measures of genetic differentiation: the sampling of only three or four individuals per aggregate may be sufficient to efficiently detect specific genetic patterns in most situa- tions. The ISS proved to be a promising methodological alternative to the more con- ventional PSS, offering much flexibility in the spatial design of sampling schemes and ensuring an optimal representativeness of landscape heterogeneity in data, with few aggregates left unsampled. Each strategy offering specific advantages, a combined use of both sampling schemes is discussed.

International audience; This study introduces a novel DNA sampling method in amphibians using skin swabs. We assessed the relevancy of skin swabs relevancy for genetic studies by amplifying a set of 17 microsatellite markers in the alpine newt Ichthyosaura alpestris, including 14 new polymorphic loci, and a set of 11 microsatellite markers in Hyla arborea, from DNA collected with buccal swabs (the standard swab method), dorsal skin swabs and ventral skin swabs. We tested for quality and quantity of collected DNA with each method by comparing electrophoresis migration patterns. The consistency between genotypes obtained from skin swabs and buccal swabs was assessed. Dorsal swabs performed better than ventral swabs in both species, possibly due to differences in skin structure. Skin swabbing proved to be a useful alternative to buccal swabbing for small or vulnerable animals: by drastically limiting handling, this method may improve the trade-off between the scientific value of collected data, individual welfare and species conservation. In addition, the 14 new polymorphic microsatellites for the alpine newt will increase the power of genetic studies in this species. In four populations from France (n = 19-25), the number of alleles per locus varied from 2 to 16 and expected heterozygosities ranged from 0.04 to 0.91. Presence of null alleles was detected in two markers and two pairs displayed gametic disequilibrium. No locus appeared to be sex-linked.

International audience; We describe a non-invasive, PCR-RFLP-based method that allows reliable determination of the European water frog species Pelophylax lessonae and Pelophylax ridibundus and the hybrid form Pelophylax esculentus. Maximum-likelihood analysis of ITS2 sequences revealed two robust monophyletic clades corresponding to water frogs of the P. lessonae and P. ridibundus groups. Three restriction enzymes (KpnI, HaeII, and SmaI) were used to digest three conserved ITS2 domains. Taxonomic identification was unambiguous; the three restriction enzymes gave the same results. A French reference sample was identified using allozyme electrophoresis. Our PCR-RFLP method confirmed circa 83% of identification of the allozyme method. We conclude that the difference between identifications was caused by introgression. The western Palearctic water frog (WPWF) group is an impressive example demonstrating the importance of molecular methods for species determination (Hotz 1983; Pagano & Joly 1999; Hotz & Semlitsch 2000; Lodé & Pagano 2000; Plötner & Ohst 2001; Plötner et al. 2001, 2007), for example, in the context of conservation and biodiversity studies. Many WPWF species are morphologically uniform but exhibit specific molecular characters such as unique protein-coding alleles (Plötner & Ohst 2001), microsatellites (Garner et al. 2000; Zeisset & Beebee 2000; Hotz et al. 2001; Christiansen 2005; Holsbeek et al. 2008, 2009a,b), nuclear sequences (Ohst 2008; Plötner et al. 2009), and mitochondrial (mt) DNA markers (Plötner 1998; Holsbeek et al. 2008; Plötner et al. 2008). Widespread hybridization between genetically similar water frog species and lineages (e.g. Akın et al. 2010) may pose serious problems for species determination. In contrast to water frogs from Anatolia and central Asia, the Central and eastern European species Pelophylax lessonae and Pelophylax ridibundus and their hybridogenetic associate Pelophylax esculentus possess distinct morphological and bioacoustic characters that allow an almost exact determination of these forms (Günther 1990; Plötner 2005). Nevertheless, the occurrence of triploid hybrids that possess either two lessonae genomes and one ridibundus genome (LLR) or two ridibundus genomes and one lessonae genome (RRL) hampers identification because of gene-dosage effects (Berger et al. 1986; Vorburger 2001): in LLR individuals, the L genome is expressed twice resulting in a lessonae-like phenotype, while RRL hybrids are often similar to P. ridibundus. In western Europe, the determination of water frogs by morphological and bioacoustic methods may also fail because of extensive hybridization between autochthonous and allochthonous lineages (Günther et al. 1979; Pagano et al. 2003; Christiansen 2005; Holsbeek et al. 2008), which produces intermediate character states for many individuals. Furthermore, character expression depends on age; compared to adults, diagnostic characters are often less clearly expressed in juveniles. Thus, genetic markers are a valuable addition to morphology for identifying adult frogs and even more useful for the determination of juveniles and larvae. Here, we present a relatively inexpensive, rapid, and non-invasive molecular method that allows distinguishing the European water frog forms P. lessonae, P. ridibundus, and P. esculentus with high certainty. Our method is based on specific restriction sites in a 271- bp PCR fragment obtained from the internal transcribed spacer 2 (ITS2) of WPWFs. This ribosomal DNA region has high inter-specific variability and is useful in phylogeny (Van Doninck et al. 2002; Gottschling et al. 2005) and for determination purposes (Joseph et al. 1999; Nikoloudakis et al. 2008), especially in hybrid complexes (Malécot et al. 2009). Ninety-one individuals were collected in Europe and Asia at 28 localities (sample 1, Table 1). Additionally, 93 specimens were collected in southern France at eight localities (sample 2, locality information was given by Pagano et al. 2001a). DNA was isolated from tissue (blood, muscle, and buccal swabs) using QIAmp blood and tissue kits (Qiagen GmbH, Hilden, Germany) or the 5% Chelex 100 ion-exchange resin method (Walsh et al. 1991). Before DNA extraction, ethanol-preserved material was soaked in three changes of distilled water over a 48-h period.

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe, drug-induced reaction that involves both the skin and the viscera. Evidence for reactivation of herpes family viruses has been seen in some DRESS patients. To understand the immunological components of DRESS and their relationship to viral reactivation, we prospectively assessed 40 patients exhibiting DRESS in response to carbamazepine, allopurinol, or sulfamethoxazole. Peripheral blood T lymphocytes from the patients were evaluated for phenotype, cytokine secretion, and repertoire of CD4+ and CD8+ and for viral reactivation. We found Epstein-Barr virus (EBV), human herpes virus 6 (HHV-6), or HHV-7 reactivation in 76% of the patients. In all patients, circulating CD8+ T lymphocytes were activated, exhibited increased cutaneous homing markers, and secreted large amounts of tumor necrosis factor-alpha and interferon-gamma. The production of these cytokines was particularly high in patients with the most severe visceral involvement. In addition, expanded populations of CD8+ T lymphocytes sharing the same T cell receptor repertoire were detected in the blood, skin, liver, and lungs of patients. Nearly half of these expanded blood CD8+ T lymphocytes specifically recognized one of several EBV epitopes. Finally, we found that the culprit drugs triggered the production of EBV in patients' EBV-transformed B lymphocytes. Thus, cutaneous and visceral symptoms of DRESS are mediated by activated CD8+ T lymphocytes, which are largely directed against herpes viruses such as EBV.

Gene flow in riverine species is constrained by the dendritic (branching) structure of the river network. Spatial genetic structure (SGS) of freshwater insects is particularly influenced by catchment characteristics and land use in the surroundings of the river. Gene flow also depends on the life cycle of organisms. Aquatic larvae mainly drift downstream whereas flying adults can disperse actively overland and along watercourses. In-stream movements can generate isolation by distance (IBD) at a local scale and differentiation between subcatchments. However, these patterns can be disrupted by overland dispersal. We studied SGS across the Loire River in the damselfly Calopteryx splendens which is able to disperse along and between watercourses. Our sampling design allowed us to test for overland dispersal effects on genetic differentiation between watercourses. Amplified fragment length polymorphism markers revealed high genetic differentiation at the catchment scale but the genetic structure did not reflect the geographical structure of sampling sites. We observed IBD patterns when considering the distance following the watercourse but also the Euclidean distance, i.e. the shortest distance, between pairs of sites. Altogether, our results support the hypothesis of overland dispersal between watercourses. From a conservation perspective, attention should be paid to the actual pathways of gene flow across complex landscapes such as river networks.

Université d'Angers, Laboratoire Paysages & Biodiversité; International audience; We have developed eight di- and tetranucleotide Lissotriton microsatellite markers. Eight loci were polymorphic in the palmate newt Lissotriton helveticus and six were polymorphic in the smooth newt L. vulgaris. Polymorphism detected in 33 and 37 individuals per species ranged from 3 to 15 alleles. These markers are suitable for the investigation of population structure, genetic variation and taxonomic identification in the two focal species, and may also be of use in other Lissotriton-Triturus species.

International audience; The cyst nematode Globodera pallida is a major pest of potato in South America where this specialist parasite is native. To investigate its phylogeography, we have genotyped individuals from 42 Peruvian populations using mitochondrial and nuclear molecular markers. A clear south-to-north phylogeographical pattern was revealed with five well-supported clades. The clade containing the southern populations is genetically more diverse and forms the most basal branch. The large divergence among cytochrome b haplotypes suggests that they diverged before human domestication of potato. As the nematodes studied have been sampled on cultivated potato, multiple host-shifts from wild to cultivated potatoes must have occurred independently in each clade. We hypothesise that this south-to-north pattern took place during the uplift of the Andes beginning 20 My ago and following the same direction. To our knowledge, this is the first study of a plant parasite sampled on cultivated plants revealing an ancient phylogeographical pattern

Although numerous species are distributed in discrete populations easily recognised by geographical barriers, continuous populations are a common feature of plants or marine organisms. This is particularly true for soil organisms as their habitat is continuous and their range cannot easily be assessed as they are buried below ground. In the case of organisms for which standard methods such as Capture/Mark/Recapture cannot be used, population genetics provide a straightforward approach to delimitate populations. In this study, we have pursued this topic with a soil-dwelling nematode ( Globodera pallida ), which parasitises potato roots and is indigenous to South America. Potential barriers to gene flow were identified using the analysis of the F ST /(1− F ST ) ratio against geographical distance and spatial autocorrelation combined with model-based clustering algorithm. Inside regions, neither genetic differentiation nor isolation by distance (IBD) occur among fields less than 50 km distant. We hypothesise that the large amount of gene flow revealed by the absence of genetic structure of this organism could be due to large passive dispersion inside an agronomic area where G. pallida has a continuous distribution and is found at high density. The first evidence of genetic differentiation appeared when a field was separated from others by an area free of farms (where G. pallida is absent or rare). Among regions, a high genetic structure coupled with an IBD pattern occurs as the consequences of the limitations of passive dispersal across deep valleys or high mountains. To our knowledge, this is the first study identifying the spatial limit of a population for a plant nematode parasite.

Tattooing is common worldwide.1 Various infections have been reported, including local infections mainly due to pyogenic bacteria and systemic infections such as hepatitis B and C and HIV.2 3 We report a large outbreak of Mycobacterium chelonae skin infection occurring in France over eight months that was related to contaminated ink. Forty eight patients presented with skin lesions, mainly pustules, occurring from 3 to 35 …

The transcriptional control of CD1d-restricted NKT cell development has remained elusive. We report that PLZF (promyelocytic leukemia zinc finger; Zbtb16), a member of the BTB/POZ-ZF family of transcription factors which includes the CD4 lineage-specific c-Krox (Th-POK, Zbtb7b), is exquisitely specific to CD1d-restricted NKT cells and human MR1-specific MAIT cells. PLZF was induced immediately after positive selection of NKT cell precursors and PLZF-deficient NKT cells failed to undergo the intrathymic expansion and effector differentiation that characterize their lineage. Instead, they preserved a naïve phenotype and were directed to lymph nodes. Conversely, transgenic expression of PLZF induced CD4 thymocytes to acquire effector differentiation and migrate to non-lymphoid tissues. We suggest that PLZF is a transcriptional signature of NKT cells that directs their innate-like effector differentiation during thymic development.