Genetic composition of Swiss and Austrian members of the apogamous Dryopteris affinis complex (Dryopteridaceae, Polypodiopsida) based on ISSR markers

We have investigated genetic variability among 56 individuals of the apogamous Dryopteris affinis complex from 9 populations in Switzerland and Austria using inter-simple sequence repeats. Our sample included 6 diploids, 48 triploids, and 1 tetraploid and 1 pentaploid plant each. We found genetic differences between and within the different ploidy levels. All diploids genetically differed from each other. In contrast, among the triploid plants we only found seven different genotypes of which one was rather common. The tetraploid and pentaploid individuals were nested among the diploids and triploids. No hypotheses have yet been proposed to explain the origin of genetic variations such as those documented here. We hope that this study stimulates new ideas about the position and the genetic background of this taxonomically difficult species group, in particular, and of apogamous species complexes in ferns in genera

Development of simple sequence repeat markers specific for the Lr34 resistance region of wheat using sequence information from rice and Aegilops tauschii

Hexaploid wheat (Triticum aestivum L.) originated about 8,000years ago from the hybridization of tetraploid wheat with diploid Aegilops tauschii Coss. containing the D-genome. Thus, the bread wheat D-genome is evolutionary young and shows a low degree of polymorphism in the bread wheat gene pool. To increase marker density around the durable leaf rust resistance gene Lr34 located on chromosome 7DS, we used molecular information from the orthologous region in rice. Wheat expressed sequence tags (wESTs) were identified by homology with the rice genes in the interval of interest, but were monomorphic in the ‘Arina'בForno' mapping population. To derive new polymorphic markers, bacterial artificial chromosome (BAC) clones representing a total physical size of ∼1Mb and belonging to four contigs were isolated from Ae. tauschii by hybridization screening with wheat ESTs. Several BAC clones were low-pass sequenced, resulting in a total of ∼560kb of sequence. Ten microsatellite sequences were found, and three of them were polymorphic in our population and were genetically mapped close to Lr34. Comparative analysis of marker order revealed a large inversion between the rice genome and the wheat D-genome. The SWM10 microsatellite is closely linked to Lr34 and has the same allele in the three independent sources of Lr34: ‘Frontana', ‘Chinese Spring', and ‘Forno', as well in most of the genotypes containing Lr34. Therefore, SWM10 is a highly useful marker to assist selection for Lr34 in breeding programs worldwid

DmOAZ, the unique Drosophila melanogaster OAZ homologue is involved in posterior spiracle development

In this paper, we study DmOAZ, the unique Drosophila melanogaster homologue of the OAZ zinc finger protein family. We show partial conservation of the zinc finger organization between DmOAZ and the vertebrate members of this family. We determine the exon/intron structure of the dmOAZ gene and deduce its open reading frame. Reverse transcriptase-polymerase chain reaction analysis shows that dmOAZ is transcribed throughout life. In the embryo, strongest DmOAZ expression is observed in the posterior spiracles. We suggest that dmOAZ acts as a secondary target of the Abd-B gene in posterior spiracle development, downstream of cut and ems. In a newly created loss-of-function mutant, dmOAZ 93 , the "filzkörper” part of the posterior spiracles, is indeed structurally abnormal. The dmOAZ 93 mutant is a larval lethal, a phenotype that may be linked to the spiracular defect. Given the dmOAZ 93 mutant as a new tool, the fruit fly may provide an alternative model for analyzing in vivo the functions of OAZ family member

Development, implementation and outcome analysis of semi-automated alerts for metformin dose adjustment in hospitalized patients with renal impairment

PURPOSE Overdosing of the oral antidiabetic metformin in impaired renal function is an important contributory cause to life-threatening lactic acidosis. The presented project aimed to quantify and prevent this avoidable medication error in clinical practice. METHODS We developed and implemented an algorithm into a hospital's clinical information system that prospectively identifies metformin prescriptions if the estimated glomerular filtration rate is below 60 mL/min. Resulting real-time electronic alerts are sent to clinical pharmacologists and pharmacists, who validate cases in electronic medical records and contact prescribing physicians with recommendations if necessary. RESULTS The screening algorithm has been used in routine clinical practice for 3 years and generated 2145 automated alerts (about 2 per day). Validated expert recommendations regarding metformin therapy, i.e., dose reduction or stop, were issued for 381 patients (about 3 per week). Follow-up was available for 257 cases, and prescribers' compliance with recommendations was 79%. Furthermore, during 3 years, we identified eight local cases of lactic acidosis associated with metformin therapy in renal impairment that could not be prevented, e.g., because metformin overdosing had occurred before hospitalization. CONCLUSIONS Automated sensitive screening followed by specific expert evaluation and personal recommendations can prevent metformin overdosing in renal impairment with high efficiency and efficacy. Repeated cases of metformin-associated lactic acidosis in renal impairment underline the clinical relevance of this medication error. Our locally developed and customized alert system is a successful proof of concept for a proactive clinical drug safety program that is now expanded to other clinically and economically relevant medication errors

Recent emergence of the wheat Lr34 multi-pathogen resistance: insights from haplotype analysis in wheat, rice, sorghum and Aegilops tauschii

Spontaneous sequence changes and the selection of beneficial mutations are driving forces of gene diversification and key factors of evolution. In highly dynamic co-evolutionary processes such as plant-pathogen interactions, the plant's ability to rapidly adapt to newly emerging pathogens is paramount. The hexaploid wheat gene Lr34, which encodes an ATP-binding cassette (ABC) transporter, confers durable field resistance against four fungal diseases. Despite its extensive use in breeding and agriculture, no increase in virulence towards Lr34 has been described over the last century. The wheat genepool contains two predominant Lr34 alleles of which only one confers disease resistance. The two alleles, located on chromosome 7DS, differ by only two exon-polymorphisms. Putatively functional homoeologs and orthologs of Lr34 are found on the B-genome of wheat and in rice and sorghum, but not in maize, barley and Brachypodium. In this study we present a detailed haplotype analysis of homoeologous and orthologous Lr34 genes in genetically and geographically diverse selections of wheat, rice and sorghum accessions. We found that the resistant Lr34 haplotype is unique to the wheat D-genome and is not found in the B-genome of wheat or in rice and sorghum. Furthermore, we only found the susceptible Lr34 allele in a set of 252 Ae. tauschii genotypes, the progenitor of the wheat D-genome. These data provide compelling evidence that the Lr34 multi-pathogen resistance is the result of recent gene diversification occurring after the formation of hexaploid wheat about 8,000years ag

An angiotensin II- and NF-κB-dependent mechanism increases connexin 43 in murine arteries targeted by renin-dependent hypertension

Aims Connexins (Cxs) play a role in the contractility of the aorta wall. We investigated how connexins of the endothelial cells (ECs; Cx37, Cx40) and smooth muscle cells (SMCs; Cx43, Cx45) of the aorta change during renin-dependent and -independent hypertension. Methods and results We subjected both wild-type (WT) mice and mice lacking Cx40 (Cx40−/−), to either a two-kidney, one-clip procedure or to N-nitro-l-arginine-methyl-ester treatment, which induce renin-dependent and -independent hypertension, respectively. All hypertensive mice featured a thickened aortic wall, increased levels of Cx37 and Cx45 in SMC, and of Cx40 in EC (except in Cx40−/− mice). Cx43 was up-regulated, with no effect on its S368 phosphorylation, only in the SMCs of renin-dependent models of hypertension. Blockade of the renin-angiotensin system of Cx40−/− mice normalized blood pressure and prevented both aortic thickening and Cx alterations. Ex vivo exposure of WT aortas, carotids, and mesenteric arteries to physiologically relevant levels of angiotensin II (AngII) increased the levels of Cx43, but not of other Cx. In the aortic SMC line of A7r5 cells, AngII activated kinase-dependent pathways and induced binding of the nuclear factor-kappa B (NF-κB) to the Cx43 gene promoter, increasing Cx43 expression. Conclusion In both large and small arteries, hypertension differently regulates Cx expression in SMC and EC layers. Cx43 is selectively increased in renin-dependent hypertension via an AngII activation of the extracellular signal-regulated kinase and NF-κB pathway

Molecular analysis of fungal disease resistance in wheat

La influencia de las Tecnologías de la Información y Comunicación (TIC) en el sector turístico y en especial en la comunicación de los productos y en la gestión de las relaciones con los públicos es ampliamente conocida. Las aplicaciones Web 2.0 basadas en comentarios y valoraciones de usuarios a escala mundial, en concreto TripAdvisor, influencian las prácticas en relaciones públicas y comunicación turísticas obligando a una cuidada gestión de la reputación online. Si por un lado las nuevas herramientas 2.0 están à disposición de las organizaciones para comunicar con sus públicos, por otro lado son también fuente de comentários y valoraciones directas que pueden reforzar positivamente la imagen de una organización o contribuir con opiniones negativas que desafian nuevas práticas en relaciones públicas. A fin de determinar si estas aplicaciones están afectando el comportamiento de planificación y reservas de productos y servicios turísticos, hicimos un estudio basado en el análisis de Burguess y Kerr (2012) dirigida a turistas portugueses