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The central dogma treats the ribosome as a molecular machine that reads one mRNA codon at a time as it adds each amino acid to its growing peptide chain. However, this and previous studies suggest that ribosomes actually perceive pairs of adjacent codons as they take three-nucleotide steps along the mRNA. We examined GNN codons, which we find are surprisingly overrepresented in eukaryote protein-coding open reading frames (ORFs), especially immediately after NNU codons. Ribosome profiling experiments in yeast revealed that ribosomes with NNU at their aminoacyl (A) site have particularly elevated densities when NNU is immediately followed (3′) by a GNN codon, indicating slower mRNA threading of the NNU codon from the ribosome’s A to peptidyl (P) sites. Moreover, if the assessment was limited to ribosomes that have only recently arrived at the next codon, by examining 21-nucleotide ribosome footprints (21-nt RFPs), elevated densities were observed for multiple codon classes when followed by GNN. This striking translation slowdown at adjacent 5′-NNN GNN codon pairs is likely mediated, in part, by the ribosome’s CAR surface, which acts as an extension of the A-site tRNA anticodon during ribosome translocation and interacts through hydrogen bonding and pi stacking with the GNN codon. The functional consequences of 5′-NNN GNN codon adjacency are expected to influence the evolution of protein coding sequences.

Plant-based natural products represent an alternative to chemical compounds for the control of mites in veterinary medicine. Here, the essential oil of Elsholtzia densa (E. densa) Benth was extracted using hydrodistillation at a rate of 1.2%. The chemical composition of the essential oil was determined by gas chromatography-mass spectrometry (GC-MS) analysis. The GC-MS analysis indicated that the principal compounds in the volatile oil of the sample were 4-Pyridinol (28.16%) and thymol (26.58%). The acaricidal activity of E. densa oil against Sarcoptes scabiei (S. scabiei) was tested in vitro. Toxicity test data were analysed using a complementary log-log (CLL) model. The E. densa oil was prepared in five concentrations by dilution with liquid paraffin (1, 2, 4, 8 and 16 mg/ml) and exhibited strong toxicity against S. scabiei with LT50 values of 16.637, 5.075, 2.884, 1.184 and 0.760 h, respectively. The LC50 values were 7.678, 4.623, 2.543, 1.502, 1.298 and 0.981 mg/ml for S. scabiei at 1, 2, 4, 8, 16 and 24 h, respectively. Compared to the control, the essential oil showed significant effects against S. scabiei in vitro. At 16 mg/ml, E. densa oil was found to kill all mites within a 16-h period. The results indicate that E. densa oil possesses potential acaricidal activity in vitro and may be exploited as a novel drug for the effective control of S. scabiei.

Abstract The conventional procedure for the construction of recombinant expression vector of a target gene includes PCR cloning and restriction enzyme mediated subcloning, which is time-consuming and sometimes troublesome because of the inefficiency of ligation. A variety of ligase-independent PCR cloning strategies have been developed, but they either involve complicated PCR procedures or need other DNA modifying enzymes. In this study, we report the design, and construction of an omnipotent expression vector pOmni, with which a target gene can be easily cloned through innovative selection-free PCR recombination cloning strategy with only one pair of primer and two times of PCR in one work day, without using any restriction enzymes, ligase and other DNA modifying enzymes. Furthermore, the target gene cloned in pOmni is ready to be high-efficiently expressed in either Escherichia coli cells or eukaryotic cells because of the elaborate design of compatible T7 promoter and CMV promoter expression elements in the vector. The cloning capability and reliability of selection-free PCR recombination cloning with pOmni were validated through cloning of 6 DNA fragments with length from 315 to 4557 bp, and the dual-expression function of the vector was verified through the cloning and expression of EGFP in E. coli BL21 and HeLa cells. pOmni developed in our study provides a powerful tool for gene cloning and expression, and is of special value for researches in which both prokaryotic and eukaryotic expression of a target gene are necessary.

The cytotoxicity effects of E. adenophorum on cell cycle and apoptosis of renal cells in Saanen goat was evaluated by TUNEL, DAPI, AO/EB staining, DNA fragmentation assay, Caspase activity, Western-blot, qRT-PCR and flow cytometry analysis. 16 saanen goats randomly divided into four groups were fed on 0%, 40%, 60% and 80% E. adenophorum diets. The Results showed that E. adenophorum induced typical apoptotic features of renal cells. E. adenophorum significantly suppressed renal cells viability, caused cell cycle activity arrest and induced typical apoptotic features in a dose-dependent manner. However, the protein levels of Fas/FasL, Bid and caspase-8 did not appear significant changes in the process of E. adenophorum-induced apoptosis. Moreover, E. adenophorum administration slightly decreased Bcl-2 expression, promoted Bax translocation to mitochondria, triggered the release of Cyt c from mitochondria into cytosol and activated caspase-9, -3, and cleaved PARP. The mitochondrial p53 translocation was significantly activated, accompanied by a significant increase in the loss of ΔΨm, Cyt c release and caspase-9 activation. Above all, these data suggest that E. adenophorum induces renal cells apoptosis via the activation of mitochondria-mediated apoptosis pathway in renal cells. These findings may provide new insights to understand the mechanisms involved in E. adenophorum-caused cytotoxicity of renal cells.

Chinese chive is a kind of medicinal and edible plant, with many diseases, and chemical fungicides are usually used for control. In order to find out the risk of pesticide residues in Chinese chives, this paper summarized relevant literatures published in recent years, and soned out and analyzed the types of pesticides used and detection techniques of common diseases in Chinese chives. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to investigate the pesticide residue status of bananas in Tangshan area and the dietary intake risk of consumers. [Methods] High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was applied to detect 70 pesticide residues in 191 batches of banana samples extracted from Tangshan area, and chronic and acute risk assessments were conducted. [Results] Among the 191 batches of bananas, 172 batches of samples were detected to contain agrochemicals, with a detection rate of 90.05%. Seventeen agrochemicals were detected, accounting for 24.29% of the total agrochemicals tested. There was a phenomenon of multiple pesticide residues in a single sample, and high detection rates were found in carbendazim (49.21%), pro-chloraz (41.88%), pyraclostrobin (34.03%) and imidacloprid (30.37%). According to GB 2763-2021 National Food Safety Standards--Maximum Residue Limits for Pesticides in Food, the over-standard rate of imidacloprid was 17.8%; and the chronic and acute dietary risks of the 17 pesticide residues were all less than 100%. [Conclusions] The pesticide residues in bananas consumed by consumers on a daily basis do not pose unacceptable dietary risks. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to understand the status of pesticide residues and dietary intake risk of Chinese chives in Tangshan area. [Methods] Sixty eight kinds of pesticide residues in 415 Chinese chive samples collected from Tangshan area were qualitatively and quantitatively determined by high -performance liquid chrom atograp hy -tan dem mass spectrometry (HPLC-MS/MS) and gas chromatography (GC) in 2020. [Results] The results showed that 41 kinds of pesticide residues were detected in the 415 Chinese chive samples, and the detection rate was 69.4% (288/415), and there was a combination of pesticides in many samples. According to the National Food Safety Standard--Maximum Residue limits of Pesticides in Food (GB 2763-2019), the residues of 12 pesticides exceeded the maximum residue limits (MRLs), and the unqualified rate was 38. 07% (158 / 415). The highest detection rate of clothianidin was 41. 20% (171/415), but there was no MRL in GB 2763-2019. The next was procymidone, the detection rate of which was 35.42% (147/415), and the over-standard rate was 30.12% (125/415). Forbidden and restricted pesticides were detected in some samples. According to the dietary exposure risk assessment, the NEDI/ADI values were all less than 1 and the intake risk was within acceptable range. In Tangshan area, the types of pesticides used in Chinese chive production are complex, and there are risks of multi-residue pollution and use of banned and restricted pesticides and unregistered pesticides. It is suggested that routine monitoring of pesticide residues and management of pesticide use should be strengthened to ensure the quality and safety of agricultural products - [Conclusions] This study provides a theoretical basis for the safe production of Chinese chive and the standardized and rational use of pesticides. [ABSTRACT FROM AUTHOR]

[Objectives] This study aimed to investigate the effects of whole-crop maize silage harvested at different stages on growth and economic benefits of beef cattle. [Methods] A total of 30 Simmental crossbred cattle weighing about 378 kg were randomly divided into three groups, respectively fed for 70 days with wholecrop maize silage harvested at milk stage (Group I), dough stage (Group II) and physiological maturity stage (Group III). Moreover, the cattle in all groups were given the same concentrate diet. [Results] There were significant differences in dry matter, crude protein and neutral detergent fiber between whole-crop maize silages harvested at different stages (P<0.05). The dry matter in Group II and III was significantly higher than that in Group I (P <0. 05). The crude protein content peaked in Group II, up to 6.37%, which was significantly higher than that in Group I (by 12.74%, P <0.05) and Group III (by 9.26%, P <0.05). Starch content significantly increased with the postponing of maize harvest (P <0. 05). The content of neutral detergent fiber in Group I was significantly higher than that in Group II (P <0.05) and Group III (P <0. 05). The average daily weight gain in Group II was 8. 53% higher than that in Group I (P <0. 05) and 3.70% higher than that in Group III (P>0.05). The dry matter intake in Group II was significantly higher than that in Group I (P <0.05) and Group III (P<0.05). There was no significant difference in feed/gain ratio between the groups (P >0. 05). The economic benefit in Group II was the highest, up to 9.99 yuan/day per capita., followed by that in Group III, 9.79 yuan/day per capita, and that in Group I was the lowest, only 8. 03 yuan/day per capita. [Conclusions] The wholecrop maize silage harvested at dough stage has the best quality and produces the highest economic returns for beef cattle. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the acaricidal activity of Ligularia virgaurea. An extract was prepared by refluxing with ethanol and steam distillation, and its toxic effect was tested in vitro against Sarcoptes scabiei. The data from the toxicity tests were analyzed using a complementary log-log (CLL) model. The ethanol extract exhibited strong acaricidal activity against these mites; at a concentration of 2 g/ml it killed all S. scabiei within 2 h and at 1 g/ml it killed all S. scabiei within 6 h. Similarly, 2, 1, 0.5 and 0.25 g/ml concentrations of the extract had strong toxicity against S. scabiei, with median lethal time (LT50) values of 0.716, 1.741, 2.968 and 4.838 h, respectively. The median lethal concentration (LC50) values were 1.388, 0.624, 0.310 and 0.213 g/ml for Scabies mite in 1, 2, 4 and 6 h, respectively. The results indicate that the L. virgaurea extract has strong acaricidal activity and may be exploited as a novel treatment for the effective control of acariasis in animals. [ABSTRACT FROM AUTHOR]