Novel Fluorescent Probe toward Fe3+ Based on Rhodamine 6G Derivatives and Its Bioimaging in Adult Mice, Caenorhabditis elegans, and Plant Tissues.

A new fluorescent probe LXY based on the rhodamine 6G platforms has been designed, synthesized, and characterized, which could recognize Fe3+ effectively in HEPES buffer (10 mM, pH = 7.4)/CH3CN (2:3, v/v). And the distinct color change and the rapid emergence of fluorescence emission at 550 nm achieved "naked eye" detection of Fe3+. The interaction mode between them was achieved by Job's plot, MS, SEM, and X-ray single-crystal diffraction. Importantly, the crystal structures proved that Fe3+ could induce the rhodamine moiety transform the closed-cycle form to the open-cycle form. But it is interesting that Fe3+ did not appear in the crystal structures. Meanwhile, the limit of detection (LOD) of LXY to Fe3+ was calculated to be 3.47 × 10-9. In addition, the RGB experiment, test papers, and silica gel plates all indicated that the probe LXY could be used to distinguish Fe3+ quantitatively and qualitatively on-site. Moreover, the probe LXY has also been successfully applied to Fe3+ image in Caenorhabditis elegans, adult mice, and plant tissues. Thus, LXY was considered to have some potential for application in bioimaging.

Long read sequencing of Toona sinensis (A. Juss) Roem: A chromosome-level reference genome for the family Meliaceae.

Chinese mahogany (Toona sinensis) is a woody plant that is widely cultivated in China and Malaysia. Toona sinensis is important economically, including as a nutritious food source, as material for traditional Chinese medicine and as a high-quality hardwood. However, the absence of a reference genome has hindered in-depth molecular and evolutionary studies of this plant. In this study, we report a high-quality T. sinensis genome assembly, with scaffolds anchored to 28 chromosomes and a total assembled length of 596 Mb (contig N50 = 1.5 Mb and scaffold N50 = 21.5 Mb). A total of 34,345 genes were predicted in the genome after homology-based and de novo annotation analyses. Evolutionary analysis showed that the genomes of T. sinensis and Populus trichocarpa diverged ~99.1-103.1 million years ago, and the T. sinensis genome underwent a recent genome-wide duplication event at ~7.8 million years and one more ancient whole genome duplication event at ~71.5 million years. These results provide a high-quality chromosome-level reference genome for T. sinensis and confirm its evolutionary position at the genomic level. Such information will offer genomic resources to study the molecular mechanism of terpenoid biosynthesis and the formation of flavour compounds, which will further facilitate its molecular breeding. As the first chromosome-level genome assembled in the family Meliaceae, it will provide unique insights into the evolution of members of the Meliaceae.

A Coumarin-Based Fluorescent Probe for Ratiometric Detection of Cu2+ and Its Application in Bioimaging.

The fluorescent probe L, based on naphthalimide-modified coumarin, was designed, synthesized, and characterized, which could recognize Cu2+ from other cations selectively and sensitively in HEPES buffer (10 mM, Ph = 7. 4)/CH3CN (1:4, V/V). When the probe L interacted with Cu2+, the color and the fluorescent intensity changed obviously and it provided the naked-eye detection for Cu2+. The recognition mode between them was achieved by Job's plot, IR, MS, SEM, and 1HNMR. In addition, test strips made from L could still interact with Cu2+ in tap water effectively. The limit of detection (LOD) of L was 3.5 × 10-6 M. Additionally, the density functional theory (DFT) calculation method was used to analyze the action mechanism of L toward Cu2+. Importantly, the fluorescent probe L could demonstrate favorable selectivity toward Cu2+ in Caenorhabditis elegans. Thus, L was considered to have some potential for application in bioimaging.

Osteogenic and adipogenic potential of porcine adipose mesenchymal stem cells.

Human, rat, and mouse studies have demonstrated the existence of a population of adipose mesenchymal stem cells (AMSCs) that can undergo multilineage differentiation in vitro. Understanding the clinical potential of AMSCs may require their use in preclinical large-animal models such as pigs. Thus, the objectives of this study were to establish a protocol for the isolation of porcine AMSCs from adipose tissue and to examine their ex vivo differentiation potential to adipocytes and osteoblast. The porcine AMSCs from passage 4 were selected for differentiation analysis. The adipocytes were identified morphologically by staining with Oil Red O, and the adipogenic marker genes were examined by RT-PCR technique. Osteogenic lineage was documented by deposition of calcium stained with Alzarin Red S, visualization of alkaline phosphatase activity, and expression of marker gene. Our result indicates that porcine AMSCs have been successfully isolated and induced differentiation into adipocytes and osteoblasts. This study suggested that porcine AMSCs are also a valuable model system for the study on the mesenchymal lineages for basic research and tissue engineering.

An optimal method of DNA silver staining in polyacrylamide gels.

A silver staining technique has widely been used to detect DNA fragments with high sensitivity on polyacrylamide gels. The conventional procedure of the silver staining is tedious, which takes about 40-60 min and needs five or six kinds of chemicals and four kinds of solutions. Although our previous improved method reduced several steps, it still needed six kinds of chemicals. The objective of this study was to improve further the existing procedures and develop an optimal method for DNA silver staining on polyacrylamide gels. The novel procedure could be completed with only four chemicals and two solutions within 20 min. The steps of ethanol, acetic acid, and nitric acid precession before silver impregnation have been eliminated and the minimal AgNO3 dose has been used in this up-to-date method. The polyacrylamide gel of the DNA silver staining displayed a golden yellow and transparent background with high sensitivity. The minimum 0.44 and 3.5 ng of DNA amount could be detected in denaturing and nondenaturing polyacrylamide gel, respectively. This result indicated that our optimal method can save time and cost, and still keep a high sensitivity for DNA staining in polyacrylamide gels.