储粮害虫低氧应答机制的研究进展

气调储粮技术是利用低氧抑制密闭的仓储系统内生物呼吸作用的原理,达到害虫防治目的一种绿色、有效手段,然而储粮害虫较强的低氧适应能力给这项技术的实际推广带来挑战.近年来,储粮害虫低氧应答机制的研究已成为研究的热点.本文将从储粮害虫低氧适应策略及相关调控机制两方面进行综述,重点探索昆虫低氧应答调控机制,包括低氧诱导因子(HI...     

Effect of omega fatty acid-rich oil blend supplementation on the growth,carcass, meat quality,and gene expression of Barbari goats

This study investigated the effect of supplementing omega fatty acids-rich oil blend, composed of sunflower oil (1.5% and 3.0%), linseed oil (1.5% and 3.0%), and FineXNV1810 (20 g) on the carcass, meat quality, fatty acid profile, and genes (peroxisome proliferator-activated receptor-α, stearoyl-CoA desaturase, acetyl-CoA carboxylase, hydroxy-3-methylglutaryl coenzyme A, and leptin) of Barbari goats. The goat kids (n = 18) were divided into three groups, namely, group A: basal diet; group B: basal diet + oil blend level 1; and group C: basal diet + oil blend level 2, and subjected to the feeding trial for 120 days followed by slaughter and meat quality studies. No treatment effect was recorded in carcass characteristics, pH, water holding capacity, and proximate composition of meat. However, a significant (p < 0.05) treatment effect was observed in cooking loss, lightness, yellowness, and shear force values of meat. There were significant differences (p < 0.05) in linoleic acid, α-linolenic acids, conjugated linoleic acid (CLA), polyunsaturated fatty acids (PUFA), n − 3 and n − 6 PUFA, PUFA/saturated fatty acids and n − 6/n − 3 ratios, and thrombogenic index among groups. An upregulation of the studied genes in the supplemented groups was observed. There were upregulations in the studied genes in the supplemented groups. Practical applications: Goat meat is in great demand the world over, especially in tropical countries, including India, and does not carry any social or religious prohibition. Although goat meat has relatively less fat, consumers express their concern over the presence of undesirable fatty acids. The present study shows that the fatty acid configuration of goat meat can be improved by a dietary supplementation of an oil blend rich in omega fatty acids. The amount of n − 3 PUFA, n − 6 PUFA, and CLA in goat meat was significantly increased due to the dietary oil blend making it healthy for the consumers. Moreover, the dietary oil blend at the studied levels did not significantly affect the growth and meat quality parameters of the goats. Thus, the studied approach can be successfully followed to produce healthier goat meat.     

Genomics-Guided Efficient Identification of 2,5-Diketopiperazine Derivatives from Actinobacteria

Secondary metabolites derived from microorganism constitute an important part of natural products. Mining of the microbial genomes revealed a large number of uncharacterized biosynthetic gene clusters, indicating their greater potential to synthetize specialized or secondary metabolites (SMs) than identified by classic fermentation and isolation approaches. Various bioinformatics tools have been developed to analyze and identify such gene clusters, thus accelerating significantly the mining process. Heterologous expression of an individual biosynthetic gene cluster has been proven as an efficient way to activate the genes and identify the encoded metabolites that cannot be detected under normal laboratory cultivation conditions. Herein, we describe a concept of genomics-guided approach by performing genome mining and heterologous expression to uncover novel CDPS-derived DKPs and functionally characterize novel tailoring enzymes embedded in the biosynthetic pathways. Recent works focused on the identification of the nucleobase-related and dimeric DKPs are also presented.     

Controlled Release of a Dual Zinc-Sensing and Gene Regulating Small Molecule from DNA Micelles

Intracellular zinc ions are essential for various biological cell processes and are often dysregulated in many diseases de-pending on their location, protein binding affinity, and concentration in the cell. Due to their prevalence in diseases, it is important to not only effectively sense but chelate the often excess amount of zinc in a cell to alleviate further disease progression. N, N, N′, N′-tetrakis (2-pyridinylmethyl)-1,2-ethanediamine (TPEN) is a selective zinc chelator but its water-insoluble nature and general cytotoxicity limit its therapeutic potential. To address these challenges, TPEN loaded nucleic acid nanocapsules (TL-NANs) were synthesized, and its dual ability to sense and suppress zinc levels intracellularly were evaluated. Additionally, TL-NANs were incubated in lung cells and shown to down regulate Eotaxin, a protein up-regulated during asthma, at significantly reduced concentrations of TPEN showcasing the therapeutic potential of this drug for asthma.     

Expression and Characterization of a New Self-Sufficient P450 Monooxygenase (P450 AZC1) from Azorhizobium caulinodans

Oxyfunctionalization of non-activated carbon bonds by P450 monooxygenases has drawn great industrial attraction. Self-sufficient P450s containing catalytic heme and reductase domains in a single polypeptide chain offer many advantages since they do not require external electron transfer partners. Here, we report the first P450 enzyme identified and expressed from Azorhizobium caulinodans. Firstly, expression conditions of P450 AZC1 were optimized for enhanced expression in E.coli. The highest P450 content was obtained in E.coli Rosetta DE3 plysS when it was incubated in TB media supplemented with 0.75 mM IPTG, 0.5 mM ALA, and 0.75 mM FeCl₃ at 25 °C for 24 hours. Subsequently, the purified enzyme showed a broad substrate spectrum including fatty acids, linear and cyclic alkanes, aromatics, and pharmaceuticals. Finally, P450 AZC1 showed optimal activity at pH 6.0 and 40 °C and a broad pH and temperature profile, making it a promising candidate for industrial applications.     

A Dual-Enzyme–Responsive DNA-Based Nanoframework Enables Controlled Co-Delivery of CRISPR-Cas9 and Antisense Oligodeoxynucleotide for Synergistic Gene Therapy

CRISPR-Cas9 has demonstrated potential in inhibiting tumor growth by downregulating target gene expression, and the efficiency is expected to be enhanced with other nucleic acid drugs. Herein, a dual-enzyme–responsive DNA-based nanoframework (NF) that enables controlled co-delivery of Cas9 ribonucleoprotein (RNP) and antisense oligodeoxynucleotide (ASO) for synergistic gene therapy is reported. NF is synthesized with acrylamide DNA (acDNA) as a cross-linker and loading site. A ternary complex containing sgRNA, ASO, and Cas9 that bound to acDNA is designed. The phase transition property of NF allows to reversibly swell and aggregate thermo-responsively for the high-capacity loading of ternary complex. RNA is cleaved from DNA–RNA complex by the overexpressed ribonuclease H for the controlled release of Cas9 RNP, and the bifurcated DNA is cleaved by the overexpressed flap structure-specific endonuclease 1 for the controlled release of overhanging ASO. The combination of gene editing with Cas9 RNP and gene silencing with ASO allows simultaneous manipulation of target gene in nucleus and its mRNA in cytoplasm, and this synergistic gene therapy has shown remarkable therapeutic effect in a breast cancer mouse model, making it a promising therapeutic strategy for future cancer treatment.     

A developed ant colony algorithm for cancer molecular subtype classification to reveal the predictive biomarker in the renal cell carcinoma

Background: Recently, researchers have been attracted in identifying the crucial genes related to cancer, whichplays important role in cancer diagnosis and treatment. However, in performing the cancer molecular subtypeclassification task from cancer gene expression data, it is challenging to obtain those significant genes due to the highdimensionality and high noise of data. Moreover, the existing methods always suffer from some issues such aspremature convergence. Methods: To address those problems, we propose a new ant colony optimization (ACO)algorithm called DACO to classify the cancer gene expression datasets, identifying the essential genes of differentdiseases. In DACO, first, we propose the initial pheromone concentration based on the weight ranking vector toaccelerate the convergence speed; then, a dynamic pheromone volatility factor is designed to prevent the algorithmfrom getting stuck in the local optimal solution; finally, the pheromone update rule in the Ant Colony System isemployed to update the pheromone globally and locally. To demonstrate the performance of the proposed algorithmin classification, different existing approaches are compared with the proposed algorithm on eight high-dimensionalcancer gene expression datasets. Results: The experiment results show that the proposed algorithm performs betterthan other effective methods in terms of classification accuracy and the number of feature sets. It can be used toaddress the classification problem effectively. Moreover, a renal cell carcinoma dataset is employed to reveal thebiological significance of the proposed algorithm from a number of biological analyses. Conclusion: The resultsdemonstrate that CAPS may play a crucial role in the occurrence and development of renal clear cell carcinoma.