Development of microsatellite and mating type markers for the pine needle pathogen Lecanosticta acicola

Lecanosticta acicola is an ascomycete that causes brown spot needle blight of pine species in many regions of the world. This pathogen is responsible for a major disease of Pinus palustris in the USA and is a quarantine organism in Europe. In order to study the genetic diversity and patterns of spread of L. acicola, eleven microsatellite markers and two mating type markers were developed. An enrichment protocol was used to isolate microsatellite-rich DNA regions and 18 primer pairs were designed to flank these regions, of which eleven were polymorphic. A total of 93 alleles were obtained across all loci from forty isolates of L. acicola from the USA with an allelic diversity range of 0.095 to 0.931 per locus. Cross-species amplification with some of the markers was obtained with L. gloeospora, L. guatemalensis and Dothistroma septosporum, but not with D. pini. Mating type (MAT) markers amplifying both idiomorphs were also developed to determine mating type distribution in populations. These markers were designed based on alignments of both idiomorphs of nine closely related plant pathogens and a protocol for multiplex PCR amplification of the MAT loci was optimised. The MAT markers are not species specific and also amplify the MAT loci in Dothistroma septosporum, D. pini, L. gloeospora and L. guatemalensis. Both types of genetic markers developed in this study will be valuable for future investigations of the population structure, genetic diversity and invasion history of L. acicola on a global scale.Financial support to Josef Janoušek from the AKTION Czech Republic – Austria (project 58p23), the Scholarship Foundation of the Republic of Austria (OeAD-GmbH, Austria),theHlavka Foundation (Czech Republic; for internship at Massey University, New Zealand) and the Intern Grant Agency of the Faculty of Forestry and Wood Technology (Mendel University in Brno, Czech Republic).The project was supported financially by COST CZ LD12031 (DIAROD), the FPS COST Action FP1102 (DIAROD) and the European Union’s Seventh Framework Programme FP7 2007–2013 (KBBE 2009–3) under grant agreement 245268 ISEFOR.http://link.springer.com/journal/13313hb201

The Hitchhiker\u27s Guide to Europe: the infection dynamics of an ongoing Wolbachia invasion and mitochondrial selective sweep in Rhagoletis cerasi

Wolbachia is a maternally inherited and ubiquitous endosymbiont of insects. It can hijack host reproduction by manipulations such as cytoplasmic incompatibility (CI) to enhance vertical transmission. Horizontal transmission of Wolbachia can also result in the colonization of new mitochondrial lineages. In this study, we present a 15-year-long survey of Wolbachia in the cherry fruit fly Rhagoletis cerasi across Europe and the spatiotemporal distribution of two prevalent strains, wCer1 and wCer2, and associated mitochondrial haplotypes in Germany. Across most of Europe, populations consisted of either 100% singly (wCer1) infected individuals with haplotype HT1, or 100% doubly (wCer1&2) infected individuals with haplotype HT2, differentiated only by a single nucleotide polymorphism. In central Germany, singly infected populations were surrounded by transitional populations, consisting of both singly and doubly infected individuals, sandwiched between populations fixed for wCer1&2. Populations with fixed infection status showed perfect association of infection and mitochondria, suggesting a recent CI-driven selective sweep of wCer2 linked with HT2. Spatial analysis revealed a range expansion for wCer2 and a large transition zone in which wCer2 splashes appeared to coalesce into doubly infected populations. Unexpectedly, the transition zone contained a large proportion (22%) of wCer1&2 individuals with HT1, suggesting frequent intraspecific horizontal transmission. However, this horizontal transmission did not break the strict association between infection types and haplotypes in populations outside the transition zone, suggesting that this horizontally acquired Wolbachiainfection may be transient. Our study provides new insights into the rarely studied Wolbachia invasion dynamics in field populations

Growth factor release in extra- and intramedullary osteosynthesis following tibial fracture

INTRODUCTION: Recent studies indicate alterations of local and systemic growth factor level during fracture healing. As a result, osteogenic and angiogenic growth factors allow us to monitor fracture healing on a molecular level. We hypothesised that closed intramedullary (IM) reaming and nail fixation, in contrast to open reduction and internal plate fixation (ORIF), could exert an effect on the cellular elements present in the intramedullary canal, leading to increased release of mediators. The purpose of the study was to investigate whether different osteosynthesis techniques influence the released quantity of cytokines. PATIENTS AND METHODS: A total of 34 patients with tibia fractures treated with IM fixation and 19 patients treated with ORIF were included in the study. In addition to clinical and radiological examination, serum concentrations of transforming growth factor beta 1(TGF-β1), macrophage-colony stimulating factor (M-CSF) and vascular endothelial growth factor (VEGF), were analysed at 1, 2, 4, 6, 8, 12, and 24 weeks after surgery. RESULTS: Expression of TGF-β1 and M-CSF was increased during the first 2 weeks of fracture healing in patients treated with the IM fixation technique compared with those treated by ORIF. After 24 weeks, M-CSF levels in patients with IM fixation were clearly higher. Conversely, VEGF levels were higher during the first 2 weeks of fracture healing in patients treated by ORIF compared with IM fixation. However, these results were not significant. CONCLUSION: Our results show that 1 week after surgery neither reamed IM fixation nor ORIF of the tibia could increase the expression of VEGF, M-CSF and TGF-β1 in its favour

How differential management strategies affect Ips typographus L. dispersal

Bark beetle outbreaks have a devastating effect on economically important forests worldwide, thus requiring extensive application of management control strategies. The presence of unmanaged protected areas in close proximity to managed forests can instigate concerns that bark beetle infestations may spread from unmanaged into managed stands. We studied the impact of differential management of forest stands on the dispersal dynamics of the European spruce bark beetle, Ips typographus, making use of inferential population genetics on mitochondrial and nuclear genomes. Bayesian inferences of migration rates and a most parsimonious dispersal tree show that outgoing gene flow was consistently higher from managed to unmanaged areas. Reason for that is likely the thorough removal of potential breeding material in managed forests and thus the dispersal of the base stock beetles from these areas to unmanaged areas where breeding material is available. Our study suggests that the potential threat posed by unmanaged to managed forests in regard to I. typographus infestation needs to be carefully re-considered