Search

ABSTRACTUnintended effects of gene edit crops may pose safety issues. Omics is a useful tool for researchers to evaluate these unexpected effects. Transcriptome and proteomics analyses were performed for two gene editors, CRISPR-Cas9 and adenine base editor (ABE) gene edit rice, as well as corresponding wild-type plants (Nipponbare). Transcriptome revealed 520 and 566 rice differentially expressed genes (DEGs) in the Cas9/Nip and ABE/Nip comparisons, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that most DEGs participated in metabolism of terpenoids and polyketones, plant–pathogen interactions, and plant signal transduction. It mainly belongs to environmental adaptation. Proteomics revealed 298 and 54 rice differentially expressed proteins (DEPs) in the Cas9/Nip and ABE/Nip comparisons, respectively. KEGG pathway enrichment analysis showed that most DEPs participated in the biosynthesis of secondary metabolite and metabolic pathways.According to integrated transcriptomes and proteomics analysis, the results showed that no newly generated genes were identified as new transcripts of these differentially expressed genes, and gene edit tools had little effect on rice transcription levels and no new proteins were generated in the gene-edited rice.

Summary: Gene stacking is a developing trend in agricultural biotechnology. Unintended effects in stacked transgenic plants are safety issues considered by the public and researchers. Omics techniques provide useful tools to assess unintended effects. In this paper, stacked transgenic maize 12‐5×IE034 that contained insecticidal cry and glyphosate tolerance G10‐epsps genes was obtained by crossing of transgenic maize varieties 12‐5 and IE034. Transcriptome and metabolome analyses were performed for different maize varieties, including 12‐5×IE034, 12‐5, IE034, and conventional varieties collected from different provinces in China. The transcriptome results were as follows. The nine maize varieties had obvious differences in gene expression. There were 3561–5538 differentially expressed genes between 12‐5×IE034 and its parents and transgenic receptor, which were far fewer than the number of differentially expressed genes in different traditional maize varieties. Cluster analysis indicated that there were close relationships between 12‐5×IE034 and its parents. The metabolome results were as follows. For the nine detected maize varieties, the number of different metabolites ranged from 0 to 240. Compared with its parents, 12‐5 and IE034, the hybrid variety 12‐5×IE034 had 15 and 112 different metabolites, respectively. Hierarchical cluster analysis with Pearson's correlation analysis showed that the differences between 12‐5×IE034 and its parents were fewer than those between other maize varieties. Shikimate pathway‐related genes and metabolites analysis results showed that the effects of hybrid stacking are less than those from transformation and differing genotypes. Thus, the differences due to breeding stack were fewer than those due to natural variation among maize varieties. This paper provides scientific data for assessing unintended effects in stacked transgenic plants. [ABSTRACT FROM AUTHOR]

In order to solve the problems of inherent complexity of analog circuits, long detecting time and low correct recognition rate in traditional fault diagnosis methods, we propose a combinational method for fault diagnosis in analog circuits, which combines improved Least Squares Support Vector Machine (LS-SVM) by Hidden Markov Model(HMM) with Volterra series. Firstly, we use frequency-domain core of Volterra series to extract circuit fault features. Then we adopt improved LS-SVM by HMM for modal classification, and the fault diagnosis Is completed. Simulation results show that compared with traditional BP neural network and LSSVM method, the proposed method Is more efficient in system fault identification and faster in fault diagnosis. [ABSTRACT FROM AUTHOR]

The potential impact of transgene escape on the environment and food safety is a major concern to the scientists and public. This work aimed to assess the effect of intein-mediated gene splitting on containment of transgene flow. Two fusion genes, EPSPSn-In and Ic-EPSPSc, were constructed and integrated into N. tabacum, using Agrobacterium tumefaciens-mediated transformation. EPSPSn-In encodes the first 295 aa of the herbicide resistance gene 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS) fused with the first 123 aa of the Ssp DnaE intein (In), whereas Ic-EPSPSc encodes the 36 C-terminal aa of the Ssp DnaE intein (Ic) fused to the rest of EPSPS C terminus peptide sequences. Both EPSPSn-In and Ic-EPSPSc constructs were introduced into the same N. tabacum genome by genetic crossing. Hybrids displayed resistance to the herbicide N-(phosphonomethyl)-glycine (glyphosate). Western blot analysis of protein extracts from hybrid plants identified full-length EPSPS. Furthermore, all hybrid seeds germinated and grew normally on glyphosate selective medium. The 6-8 leaf hybrid plants showed tolerance of 2000 ppm glyphosate in field spraying. These results indicated that functional EPSPS protein was reassembled in vivo by intein-mediated trans-splicing in 100% of plants. In order to evaluate the effect of the gene splitting technique for containment of transgene flow, backcrossing experiments were carried out between hybrids, in which the foreign genes EPSPSn-In and Ic-EPSPSc were inserted into different chromosomes, and non-transgenic plants NC89. Among the 2812 backcrossing progeny, about 25% (664 plantlets) displayed glyphosate resistance. These data indicated that transgene flow could be reduced by 75%. Overall, our findings provide a new and highly effective approach for biological containment of transgene flow. [ABSTRACT FROM AUTHOR]

The potential impact of transgene escape on the environment and food safety is a major concern to the scientists and public. This work aimed to assess the effect of intein-mediated gene splitting on containment of transgene flow. Two fusion genes, EPSPSn-In and Ic-EPSPSc, were constructed and integrated into N. tabacum, using Agrobacterium tumefaciens-mediated transformation. EPSPSn-In encodes the first 295 aa of the herbicide resistance gene 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS) fused with the first 123 aa of the Ssp DnaE intein (In), whereas Ic-EPSPSc encodes the 36 C-terminal aa of the Ssp DnaE intein (Ic) fused to the rest of EPSPS C terminus peptide sequences. Both EPSPSn-In and Ic-EPSPSc constructs were introduced into the same N. tabacum genome by genetic crossing. Hybrids displayed resistance to the herbicide N-(phosphonomethyl)-glycine (glyphosate). Western blot analysis of protein extracts from hybrid plants identified full-length EPSPS. Furthermore, all hybrid seeds germinated and grew normally on glyphosate selective medium. The 6-8 leaf hybrid plants showed tolerance of 2000 ppm glyphosate in field spraying. These results indicated that functional EPSPS protein was reassembled in vivo by intein-mediated trans-splicing in 100% of plants. In order to evaluate the effect of the gene splitting technique for containment of transgene flow, backcrossing experiments were carried out between hybrids, in which the foreign genes EPSPSn-In and Ic-EPSPSc were inserted into different chromosomes, and non-transgenic plants NC89. Among the 2812 backcrossing progeny, about 25% (664 plantlets) displayed glyphosate resistance. These data indicated that transgene flow could be reduced by 75%. Overall, our findings provide a new and highly effective approach for biological containment of transgene flow. [ABSTRACT FROM AUTHOR]

Aiming at method of tracking status of nonlinear system quickly and timely, this paper studied application of QCNN in nonlinear tracking system. In the case that Lyapunov function was convergent in exponent rate, it designed one controller with other parameter. On the basis of this controller, QCNN controlled system tracked three kinds of nonlinear system, which were separately certain system, nonlinear data system without known parameters and its function relation, and system of Chua's circuit. Simulations show that QCNN system can realize effective tracking for status of nonlinear problem by suitable controller. Furthermore, the simulation results provide reference and illustration to relationship between system's complexity and accurate exhausted time of tracking. The new designed controller and disposing adopted methods in the paper can give some thinking means for QCNN theory and its application research. [ABSTRACT FROM AUTHOR]

Simultaneous monitoring of many functioning β-cells is essential for understanding β-cell dysfunction as an early event in the progression to diabetes. Intrinsic optical signal (IOS) imaging has been shown to allow high resolution detection of stimulus-evoked physiological responses in the retina and other neural tissues. In this paper, we demonstrate the feasibility of using IOS imaging for functional examination of insulin secreting INS-1 cells, a popular model for investigating diabetes associated β-cell dysfunction. Our experiments indicate that IOS imaging permits simultaneous monitoring of glucose-stimulated physiological responses in multiple cells with high spatial (sub-cellular) and temporal (sub-second) resolution. Rapid IOS image sequences revealed transient optical responses that had time courses tightly correlated with the glucose stimulation.