Reference genes for gene expression studies in wheat flag leaves grown under different farming conditions

<p>Abstract</p> <p>Background</p> <p>Internal control genes with highly uniform expression throughout the experimental conditions are required for accurate gene expression analysis as no universal reference genes exists. In this study, the expression stability of 24 candidate genes from <it>Triticum aestivum </it>cv. Cubus flag leaves grown under organic and conventional farming systems was evaluated in two locations in order to select suitable genes that can be used for normalization of real-time quantitative reverse-transcription PCR (RT-qPCR) reactions. The genes were selected among the most common used reference genes as well as genes encoding proteins involved in several metabolic pathways.</p> <p>Findings</p> <p>Individual genes displayed different expression rates across all samples assayed. Applying geNorm, a set of three potential reference genes were suitable for normalization of RT-qPCR reactions in winter wheat flag leaves cv. Cubus: <it>TaFNRII </it>(ferredoxin-NADP(H) oxidoreductase; AJ457980.1), <it>ACT2 </it>(actin 2; TC234027), and <it>rrn26 </it>(a putative homologue to RNA 26S gene; AL827977.1). In addition of these three genes that were also top-ranked by NormFinder, two extra genes: <it>CYP18-2 </it>(Cyclophilin A, AY456122.1) and <it>TaWIN1 </it>(14-3-3 like protein, AB042193) were most consistently stably expressed.</p> <p>Furthermore, we showed that <it>TaFNRII, ACT2</it>, and <it>CYP18-2 </it>are suitable for gene expression normalization in other two winter wheat varieties (Tommi and Centenaire) grown under three treatments (organic, conventional and no nitrogen) and a different environment than the one tested with cv. Cubus.</p> <p>Conclusions</p> <p>This study provides a new set of reference genes which should improve the accuracy of gene expression analyses when using wheat flag leaves as those related to the improvement of nitrogen use efficiency for cereal production.</p

Synergism between particle-based multiplexing and microfluidics technologies may bring diagnostics closer to the patient

In the field of medical diagnostics there is a growing need for inexpensive, accurate, and quick high-throughput assays. On the one hand, recent progress in microfluidics technologies is expected to strongly support the development of miniaturized analytical devices, which will speed up (bio)analytical assays. On the other hand, a higher throughput can be obtained by the simultaneous screening of one sample for multiple targets (multiplexing) by means of encoded particle-based assays. Multiplexing at the macro level is now common in research labs and is expected to become part of clinical diagnostics. This review aims to debate on the “added value” we can expect from (bio)analysis with particles in microfluidic devices. Technologies to (a) decode, (b) analyze, and (c) manipulate the particles are described. Special emphasis is placed on the challenges of integrating currently existing detection platforms for encoded microparticles into microdevices and on promising microtechnologies that could be used to down-scale the detection units in order to obtain compact miniaturized particle-based multiplexing platforms

Synthesis of multi-block copolymer stars using a simple iterative Cu(0)-mediated radical polymerization technique

A new iterative copper(0)-mediated radical polymerization approach is presented that represents a significant advance in the synthesis of high order multi-block star copolymers. The synthesis of these materials can now be achieved in high yield and with controlled structural complexity, with purification only required at the last step. The approach is general, facile and offers the opportunity to synthesize new copolymer stars.</p

NUMERICAL SIMULATION OF A GUITAR

The purpose of this study is to present a time-domain numerical modeling of the guitar. The model involves the transverse displacement of the string excited by a force pulse, the flexural motion of the soundboard and the sound radiation in the air. We use a specific spectral method for solving the Kirchhoff-Love’s dynamic plate model for orthotropic material, a fictitious domain method for solving the fluid-structure interaction and a conservative scheme for the time discretization. One of the originality of the proposed scheme is a stable coupling method between a continuous time resolution and a discrete one. Key words. Kirchhoff-Love’s plate model, fluid-structure interaction, mixed finite elements, fictitious domain method, spectral method, energy method, stability. AMS subject classifications. 65M12, 65M60, 65M70. 1. Introduction. Th

RNA quality assessment: a view from plant qPCR studies

Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) is probably the most common molecular technique used in transcriptome analyses today. The simplicity of the technology and associated protocols that generate results without the need to understand the underlying principles has made RT-qPCR the method of choice for RNA quantification. Rather than the ‘gold standard technology’ often used to describe it, the performance of RT-qPCR suffers from considerable pitfalls during general workflow. The inconsistency of conventional methods for the evaluation of RNA quality and its influence on qPCR performance as well as stability of reference genes is summarized and discussed here