Open areas in a landscape enhance pollen-mediated gene flow of a tree species: evidence from northern Switzerland

Habitat fragmentation often has negative consequences for genetic diversity, and thereby for the viability of populations. However, these negative consequences might be counteracted by gene flow as the latter provides functional connectivity between apparently isolated habitat fragments. Gene flow is itself influenced by landscape structure and composition, and it is therefore important to understand the relationship between gene flow and landscape structure and composition. We used linear LAD regression models to investigate the relationship between contemporary gene flow by pollen in the rare, insect-pollinated forest tree Sorbus domestica and several landscape features. None of the landscape components—which included closed forest, deep valleys, open land and settlements—proved to be an impermeable barrier to gene flow by pollen. We found evidence that settlements, large open areas, and a pronounced topography increased long-distance gene flow in the landscape as compared to a random model including all possible gene flow trajectories. These results are encouraging from a conservation view, as gene flow in species pollinated by generalist insects seems to provide functional connectivity and may help to maintain genetic diversity in rare plant species in fragmented landscape

Characterisation of mixed virus infections in Ribes species in Switzerland

Various virus disease-like symptoms are frequently observed in Ribes sp. in Switzerland but the aetiology remains poorly documented, although a number of viruses infecting Ribes sp. were described elsewhere. Therefore, symptomatic and apparently healthy plants from diverse origins were analysed by electron microscopy (EM), immunoprecipitation electron microscopy (IPEM), Western blot and (RT-)PCR. By EM, at least four different particle types, often in combination, were observed. (1) Bacilliform particles were typical for the Badnavirus genus with dimensions of 145 x 28 nm. This virus was identified by PCR as the Gooseberry vein banding associated virus (GVBaV). (2) Filamentous particles were mainly observed on black currants with downward rolling of leaves with interveinal reddening during summer and fall. We tentatively named this unknown virus Blackcurrant leafroll-associated virus 1 (BCLRaV-1). In phylogenetic analysis of HSP70h nucleotide sequences, BCLRaV-1 felt in the Closterovirus genus. In Western blot analysis, one dominant protein with an estimated molecular weight of about 28 kDa was detectable. The virus was shown to be different from the Raspberry mottle closterovirus (RMoV) by IPEM and RT-PCR. (3) RTPCR and sequencing of products also clearly demonstrated the presence in our Ribes samples of Rubus chlorotic mottle virus (RuCMV), a Sobemovirus recently described in Scotland. This finding correlates with the presence of the 30 nm diameter particles observed by EM. (4) A further structure with isometrical particles of 60 nm could not yet be attributed to a particular genus. Altogether, our data suggest the presence of multiple virus infections i

Identification of a Lotus viral pathogen

A virus collection was used to identify a pathogen suitable for laboratory use with the model legume Lotus japonicus. Several Lotus species or L. japonicus accessions were tested and various degrees of susceptibility to the Arabis mosaic virus derived from barley (ArMV-ba) were found. Virus multiplication and persistence in Lotus tissue were examined, as well as plant responses to it. Sensitivity to the virus among the accessions and species is discussed in light of their geographical origi

Nomenclature of grapevine leafroll-associated putative closteroviruses

Comparative immunoenzymatic (ELISA), immunoelectron microscopic (IEM) and immunoblotting tests were carried out with antisera produced in different laboratories and commercial diagnostic kits on closterolike viruses reported in the literature under the name of grapevine corky bark-associated virus (GCBaV) and grapevine leafroll-associated viruses IIa and IIb (GLRaV IIa and GLRaV IIb). The results of these studies have established that GCBaV is the same as GLRaV IIb and that both viruses are apparently identical to an isolate of GLRaV-2 identified in France, whose designation as the authentic GLRaV 2 is proposed. GLRaV IIa is serologically distinct from all known clostero-like viruses of the grapevine and, therefore, the provisional name of grapevine leafroll-associated Virus 6 (GLRaV-6) is suggested for it

A case of Muir-Torre syndrome associated with mucinous hepatic cholangiocarcinoma and a novel germline mutation of the MSH2 gene

Muir-Torre syndrome (MTS) is a rare cancer-predisposing syndrome that is autosomal dominantly inherited and characterized by the development of sebaceous skin lesions (adenomas, epitheliomas, basaliomas and carcinomas). These lesions are typically associated with tumors that belong to the spectrum of hereditary nonpolyposis colorectal cancer (HNPCC) (i.e. tumors of the colorectum, endometrium, stomach or ovary). Biliary malignancy in association with MTS has only rarely been reported. We report a case of Muir-Torre syndrome associated with intrahepatic cholangiocarcinoma, a location not previously described, and associated with a novel missense mutation of the MSH2 gene (c.2026T>C), predicted to disrupt the function of the gen

Toward a Social Practice Theory of Relational Competing

This paper brings together the competitive dynamics and strategy-aspractice literatures to investigate relational competition. Drawing on a global ethnography of the reinsurance market, we develop the concept of micro-competitions, which are the focus of competitors’ everyday competitive practices. We find variation in relational or rivalrous competition by individual competitors across the phases of a micro-competition, between competitors within a micro-competition, and across multiple micro-competitions. These variations arise from the interplay between the unfolding competitive arena and the implementation of each firm’s strategic portfolio. We develop a conceptual framework that makes four contributions to: relational competition; reconceptualizing action and response; elaborating on the awareness-motivation-capability framework within competitive dynamics; and the recursive dynamic by which implementing strategy inside firms shapes, and is shaped by, the competitive arena

A case of Muir-Torre syndrome associated with mucinous hepatic cholangiocarcinoma and a novel germline mutation of the MSH2 gene.

Muir-Torre syndrome (MTS) is a rare cancer-predisposing syndrome that is autosomal dominantly inherited and characterized by the development of sebaceous skin lesions (adenomas, epitheliomas, basaliomas and carcinomas). These lesions are typically associated with tumors that belong to the spectrum of hereditary nonpolyposis colorectal cancer (HNPCC) (i.e., tumors of the colorectum, endometrium, stomach or ovary). Biliary malignancy in association with MTS has only rarely been reported. We report a case of Muir-Torre syndrome associated with intrahepatic cholangiocarcinoma, a location not previously described, and associated with a novel missense mutation of the MSH2 gene (c.2026T > C), predicted to disrupt the function of the gene

Belowground DNA-based techniques: untangling the network of plant root interactions

Contains fulltext : 91591.pdf (publisher's version ) (Closed access)7 p

Community genetics in the time of next-generation molecular technologies

Understanding the interactions of co-occurring species within and across trophic levels provides key information needed for understanding the ecological and evolutionary processes that underlie biological diversity. As genetics has only recently been integrated into the study of community-level interactions, the time is right for a critical evaluation of potential new, gene-based approaches to studying communities. Next-generation molecular techniques, used in parallel with field-based observations and manipulative experiments across spatio-temporal gradients, are key to expanding our understanding of community-level processes. Here, we introduce a variety of ‘-omics’ tools, with recent studies of plant–insect herbivores and of ectomycorrhizal systems providing detailed examples of how next-generation approaches can revolutionize our understanding of interspecific interactions. We suggest ways that novel technologies may convert community genetics from a field that relies on correlative inference to one that reveals causal mechanisms of genetic co-variation and adaptations within communities

Monitoring of species' genetic diversity in Europe varies greatly and overlooks potential climate change impacts.

Genetic monitoring of populations currently attracts interest in the context of the Convention on Biological Diversity but needs long-term planning and investments. However, genetic diversity has been largely neglected in biodiversity monitoring, and when addressed, it is treated separately, detached from other conservation issues, such as habitat alteration due to climate change. We report an accounting of efforts to monitor population genetic diversity in Europe (genetic monitoring effort, GME), the evaluation of which can help guide future capacity building and collaboration towards areas most in need of expanded monitoring. Overlaying GME with areas where the ranges of selected species of conservation interest approach current and future climate niche limits helps identify whether GME coincides with anticipated climate change effects on biodiversity. Our analysis suggests that country area, financial resources and conservation policy influence GME, high values of which only partially match species' joint patterns of limits to suitable climatic conditions. Populations at trailing climatic niche margins probably hold genetic diversity that is important for adaptation to changing climate. Our results illuminate the need in Europe for expanded investment in genetic monitoring across climate gradients occupied by focal species, a need arguably greatest in southeastern European countries. This need could be met in part by expanding the European Union's Birds and Habitats Directives to fully address the conservation and monitoring of genetic diversity