Ligation-Based qPCR-Amplification Assay for Radiolabel-Free Detection of ATP and NAD⁺ with High Selectivity and Sensitivity

We have developed a new sensing system based on quantitative real-time polymerase chain reaction assay (qPCR) to detect adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide (NAD+) with high sensitivity and selectivity. T4 DNA ligase can catalyze the ligation of two short oligonucleotides (DNA1 and DNA2), which complement a template (cDNA), in the presence of its cofactor, ATP, resulting in increased template concentration and decreased Ct values in qPCR assays. Similarly, the Escherichia coli DNA ligase is also able to catalyze the ligation of DNA1 and DNA2 upon the addition of NAD+. Moreover, this approach has potential for detecting other important cofactors in related systems. Therefore, as a convenient and sensitive strategy, the method may light new beacons and find broad application in biological fields

Mulching films affecting soil bacterial and fungal communities in a drip-irrigated potato soil

ABSTRACT Film mulching is an effective water-saving and yield-increasing measure for potato production in Northwest China. However, the response mechanism of microbial communities to mulching films in the soil is still unclear. In this study, polyethylene film mulching (PM), biodegradable film mulching (BM), liquid film mulching (LM), and non-mulching (NM) were applied on the drip-irrigated soil to investigate the effects of mulching films on soil bacterial and fungal communities through DNA sequencing, Pearson correlation analysis, and redundancy analysis. The results showed that LM treatment significantly increased the contents of soil mineral N (SMN), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) (p</div

Head structure of <i>Melanerpes Aurifrons</i> Golden-fronted Woodpecker.

<p>The photo is downloaded from (<a href="http://digimorph.org/specimens/Melanerpes_aurifrons/" target="_blank">http://digimorph.org/specimens/Melanerpes_aurifrons/</a>).</p

The contours of von Mises stress of the endoskeleton at different time under 1m/s impact velocity.

<p>(a) the original model and (b) the no-hyoid model. (The unit of the color bar is 1×10⁵<i>Pa</i>).</p

Curves of the relative mechanical energy with time for the original, the no-hyoid, the stiffer muscle and the no-hyoid & stiffer muscle model.

<p>(under 1m/s impact velocity).</p

c‑Yes Tyrosine Kinase Is a Potent Suppressor of ES Cell Differentiation and Antagonizes the Actions of Its Closest Phylogenetic Relative, c‑Src

Embryonic stem (ES) cells are derived from the inner cell mass of the blastocyst stage embryo and are characterized by self-renewal and pluripotency. Previous work has shown that Src-family tyrosine kinases display dynamic expression and activity changes during ES cell differentiation, suggesting distinct functions in the control of developmental fate. Here we used ES cells to test the hypothesis that c-Src and its closest phylogenetic relative, c-Yes, act in biological opposition despite their strong homology. Unlike c-Src, enforced expression of active c-Yes blocked ES cell differentiation to embryoid bodies by maintaining pluripotency gene expression. To explore the interplay of c-Src and c-Yes in ES cell differentiation, we engineered c-Src and c-Yes mutants that are resistant to A-419259, a potent pyrrolopyrimidine inhibitor of the Src kinase family. Previous studies have shown that A-419259 treatment blocks all Src-family kinase activity in ES cells, preventing differentiation while maintaining pluripotency. Expression of inhibitor-resistant c-Src but not c-Yes rescued the A-419259 differentiation block, resulting in a cell population with properties of both primitive ectoderm and endoderm. Remarkably, when inhibitor-resistant c-Src and c-Yes were expressed together in ES cells, c-Yes activity suppressed c-Src-mediated differentiation. These studies show that even closely related kinases such as c-Src and c-Yes have unique and opposing functions in the same cell type. Selective agonists or inhibitors of c-Src versus c-Yes activity may allow more precise pharmacological manipulation of ES cell fate and have broader applications in other biological systems that express multiple Src family members such as tumor cells

Materials properties adopted.

<p>Materials properties adopted.</p

Curves of the contact force between the beak and the trunk for the original model and the no-hyoid model.

<p>(under 1m/s impact velocity)</p

Curves of the relative mechanical energy <i>E</i>_<i>r</i> and the deformation energy <i>E</i>_<i>w</i> of the whole head for the original model and the no-hyoid model.

<p>(under 1m/s impact velocity).</p

Curves of the average SSS for the original, the no-hyoid, the stiffer muscle and the no-hyoid & stiffer muscle model.

<p>(under 1m/s impact velocity).</p