Cloning and Expression Patterns of Coumarate-3-hydroxylase Gene from Angelica sinensis and Its Correlation with Content of Ferulic Acid / 中国实验方剂学杂志

ObjectiveTo clone coumarate-3-hydroxylase gene （C3H） from Angelica sinensis， and analyze the correlation between its bioinformatics， expression patterns and content of ferulic acid， and to explore the functions of ASC3H. MethodReal-time polymerase chain reaction （Real-time PCR） was used to clone the full-length cDNA of ASC3H based on the transcriptome dataset of A. sinensis， and the bioinformatics analysis of the gene sequence was carried out. Real-time PCR and high performance liquid chromatography （HPLC） were used to determine relative expression of ASC3H and content of ferulic acid in different root tissues of A. sinensis （periderm， cortex and stele）. ResultThe open reading frame （ORF） of ASC3H （GenBank accession number： MN2550298） was 1 530 bp， encoding 509 amino acids， with a theoretical molecular weight of 57.86 kDa and an isoelectric point of 8.36. It was a hydrophilic protein that was located in the chloroplast with multiple phosphorylation sites and a transmembrane region， and contained a conserved domain CGYDWPKGYGPIINVW_P450 （383-399 aa） in cytochrome P450. Multiple amino acid sequence alignment analysis showed that ASC3H had high similarity with C3H from other plants， especially Ammi majus in Umbelliferae. The Real-time PCR revealed that ASC3H had different expressions in periderm， cortex and stele tissues of A. sinensis roots. It was found from HPLC that the cortex tissues had the highest content of ferulic acid， and the stele tissues had the lowest. ConclusionASC3H was successfully cloned from A. sinensis， and its sequence characteristics were understood more clearly， suggesting that ASC3H might be involved in the ferulic acid biosynthesis pathway of A. sinensis. This paper provided a basis for further studying the functions of the gene and exploring the biosynthesis and regulation mechanism of ferulic acid in A. sinensis， while laying the foundation for the genetic improvement of A. sinensis．

Pluripotent stem cells secrete Activin A to improve their epiblast competency after injection into recipient embryos

It is not fully clear why there is a higher contribution of pluripotent stem cells (PSCs) to the chimera produced by injection of PSCs into 4-cell or 8-cell stage embryos compared with blastocyst injection. Here, we show that not only embryonic stem cells (ESCs) but also induced pluripotent stem cells (iPSCs) can generate F0 nearly 100% donor cell-derived mice by 4-cell stage embryo injection, and the approach has a "dose effect". Through an analysis of the PSC-secreted proteins, Activin A was found to impede epiblast (EPI) lineage development while promoting trophectoderm (TE) differentiation, resulting in replacement of the EPI lineage of host embryos with PSCs. Interestingly, the injection of ESCs into blastocysts cultured with Activin A (cultured from 4-cell stage to early blastocyst at E3.5) could increase the contribution of ESCs to the chimera. The results indicated that PSCs secrete protein Activin A to improve their EPI competency after injection into recipient embryos through influencing the development of mouse early embryos. This result is useful for optimizing the chimera production system and for a deep understanding of PSCs effects on early embryo development.

A Hydrogen Peroxide Sensor Based on Pt@Au Nanoparticles Loading to Polyethyleneimine Functionalized Carbon Nanotubes / 分析化学

A novel hydrogen peroxide sensor was fabricated by the seed-mediated growth method. First, polyethyleneimine(PEI) functionalized multiwalled carbon nanotubes(MWNTs) were used as growth scaffold on the glass carbon electrode ( GCE). Then, Au nanoparticles were electrodeposited uniformly as seeds. Finally, Pt nanoparticles ( PtNPs ) grew on Au nanoparticles to form Pt @ Au core-shell structure nanocomposite. A new type of electrochemical sensor based on Pt @ Au / PEI-MWNTs nanocomposites for detection of hydrogen peroxide was developed, and the designed Pt@ Au / PEI-MWNTs/ GCE was characterized by electrochemical methods and field emission scanning electron microscopy (FESEM). The Differential pulse experimental results showed that the modified electrode exhibited excellent electrocatalytic activity towards the reduction of H2 O2 with the wide linear range from 9. 2 ×10-8 mol/ L to 1. 3 ×10-3 mol/ L. The correlation coefficient was 0. 9994 and the low detection limit was 3. 1×10-8 mol/ L at the signal-to-noise of 3.