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1.
Plant Biotechnol J ; 21(7): 1454-1464, 2023 07.
Article in English | MEDLINE | ID: mdl-37139586

ABSTRACT

Using genetic resistance against bacterial blight (BB) caused by Xanthomonas oryzae pathovar oryzae (Xoo) is a major objective in rice breeding programmes. Prime editing (PE) has the potential to create novel germplasm against Xoo. Here, we use an improved prime-editing system to implement two new strategies for BB resistance. Knock-in of TAL effector binding elements (EBE) derived from the BB susceptible gene SWEET14 into the promoter of a dysfunctional executor R gene xa23 reaches 47.2% with desired edits including biallelic editing at 18% in T0 generation that enables an inducible TALE-dependent BB resistance. Editing the transcription factor TFIIA gene TFIIAγ5 required for TAL effector-dependent BB susceptibility recapitulates the resistance of xa5 at an editing efficiency of 88.5% with biallelic editing rate of 30% in T0 generation. The engineered loci provided resistance against multiple Xoo strains in T1 generation. Whole-genome sequencing detected no OsMLH1dn-associated random mutations and no off-target editing demonstrating high specificity of this PE system. This is the first-ever report to use PE system to engineer resistance against biotic stress and to demonstrate knock-in of 30-nucleotides cis-regulatory element at high efficiency. The new strategies hold promises to fend rice off the evolving Xoo strains and protect it from epidemics.


Subject(s)
Oryza , Xanthomonas , Transcription Activator-Like Effectors/genetics , Transcription Activator-Like Effectors/metabolism , Oryza/metabolism , Plant Breeding , Promoter Regions, Genetic , Disease Resistance/genetics , Plant Diseases/genetics , Plant Diseases/prevention & control , Plant Diseases/microbiology
2.
J Integr Plant Biol ; 65(4): 900-906, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36478403

ABSTRACT

Low efficiency is the main obstacle to using prime editing in maize (Zea mays). Recently, prime-editing efficiency was greatly improved in mammalian cells and rice (Oryza sativa) plants by engineering prime-editing guide RNAs (pegRNAs), optimizing the prime editor (PE) protein, and manipulating cellular determinants of prime editing. In this study, we tested PEs optimized via these three strategies in maize. We demonstrated that the ePE5max system, composed of PEmax, epegRNAs (pegRNA-evopreQ. 1), nicking single guide RNAs (sgRNAs), and MLH1dn, efficiently generated heritable mutations that conferred resistance to herbicides that inhibit 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), acetolactate synthase (ALS), or acetyl CoA carboxylase (ACCase) activity. Collectively, we demonstrate that the ePE5max system has sufficient efficiency to generate heritable (homozygous or heterozygous) mutations in maize target genes and that the main obstacle to using PEs in maize has thus been removed.


Subject(s)
Herbicides , Zea mays , Zea mays/genetics , Herbicides/pharmacology , Mutation/genetics , Gene Editing , CRISPR-Cas Systems
3.
Phytochem Anal ; 32(2): 141-152, 2021 Apr.
Article in English | MEDLINE | ID: mdl-31512326

ABSTRACT

INTRODUCTION: Polygoni Orientalis Fructus (POF) is a clinically effective Chinese medicine. Raw POF (RPOF) and POF Tostus (POFT) are used separately in clinics. However, incomplete progress has been made on quality control. OBJECTIVE: To establish a comprehensive method for quality assessment of RPOF and POFT and to discriminate these two varieties. METHODOLOGY: High-performance liquid chromatography combined with the diode array detector (HPLC-DAD) methods were developed for fingerprinting and quantitative analysis of seven major compounds in RPOF and POFT, and the main components were determined by HPLC-DAD coupled with Fourier-transform ion cyclotron resonance-mass spectrometry. Chemometric approaches were performed to discriminate RPOF and POFT and to screen discriminatory components. RESULTS: Fingerprints were established and 12 common peaks were identified, cannabisin G and cannabisin E were firstly identified from POF. In quantitative analysis, all analytes showed good regression (R > 0.9996) within test ranges and the recovery of the method was in the range 96.6-104.3%. Fingerprints in conjunction with similarity analysis and hierarchical clustering analysis (HCA) demonstrated the consistent quality of RPOF and showed a clear discrimination between RPOF and POFT. Principal component analysis, partial least-squares discriminant analysis, and heatmap-HCA on quantitative data not only gave a clear differentiation between RPOF and POFT, but they also suggested that quercetin, 3,5,7-trihydroxychromone, and N-trans-feruloyltyramine acted as the main factors responsible for the sample differences. CONCLUSIONS: Chromatographic analysis in combination with chemometric analysis provides a simple and reliable method of comparing and evaluating the qualities of RPOF and POFT.


Subject(s)
Drugs, Chinese Herbal , Chromatography, High Pressure Liquid , Fruit , Principal Component Analysis , Quality Control
4.
Plant Physiol ; 181(4): 1441-1448, 2019 12.
Article in English | MEDLINE | ID: mdl-31558579

ABSTRACT

The lack of efficient delivery methods is a major barrier to clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas)-mediated genome editing in many plant species. Combinations of morphogenic regulator (MR) genes and ternary vector systems are promising solutions to this problem. In this study, we first demonstrated that MR vectors greatly enhance maize (Zea mays) transformation. We then tested a CRISPR/Cas9 MR vector in maize and found that the MR and CRISPR/Cas9 modules have no negative influence on each other. Finally, we developed a novel ternary vector system to integrate the MR and CRISPR/Cas modules. Our ternary vector system is composed of new pGreen-like binary vectors, here named pGreen3, and a pVS1-based virulence helper plasmid, which also functions as a replication helper for the pGreen3 vectors in Agrobacterium tumefaciens The pGreen3 vectors were derived from the plasmid pRK2 and display advantages over pGreen2 vectors regarding both compatibility and stability. We demonstrated that the union of our ternary vector system with MR gene modules has additive effects in enhancing maize transformation and that this enhancement is especially evident in the transformation of recalcitrant maize inbred lines. Collectively, our ternary vector system-based tools provide a user-friendly solution to the low efficiency of CRISPR/Cas delivery in maize and represent a basic platform for developing efficient delivery tools to use in other plant species recalcitrant to transformation.


Subject(s)
CRISPR-Cas Systems/genetics , Genes, Plant , Genetic Vectors/genetics , Morphogenesis/genetics , Zea mays/growth & development , Zea mays/genetics , Agrobacterium tumefaciens/genetics , Transformation, Genetic
5.
Plant Mol Biol ; 96(4-5): 445-456, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29476306

ABSTRACT

KEY MESSAGE: We present novel observations of high-specificity SpCas9 variants, sgRNA expression strategies based on mutant sgRNA scaffold and tRNA processing system, and CRISPR/Cas9-mediated T-DNA integrations. Specificity of CRISPR/Cas9 tools has been a major concern along with the reports of their successful applications. We report unexpected observations of high frequency off-target mutagenesis induced by CRISPR/Cas9 in T1 Arabidopsis mutants although the sgRNA was predicted to have a high specificity score. We also present evidence that the off-target effects were further exacerbated in the T2 progeny. To prevent the off-target effects, we tested and optimized two strategies in Arabidopsis, including introduction of a mCherry cassette for a simple and reliable isolation of Cas9-free mutants and the use of highly specific mutant SpCas9 variants. Optimization of the mCherry vectors and subsequent validation found that fusion of tRNA with the mutant rather than the original sgRNA scaffold significantly improves editing efficiency. We then examined the editing efficiency of eight high-specificity SpCas9 variants in combination with the improved tRNA-sgRNA fusion strategy. Our results suggest that highly specific SpCas9 variants require a higher level of expression than their wild-type counterpart to maintain high editing efficiency. Additionally, we demonstrate that T-DNA can be inserted into the cleavage sites of CRISPR/Cas9 targets with high frequency. Altogether, our results suggest that in plants, continuous attention should be paid to off-target effects induced by CRISPR/Cas9 in current and subsequent generations, and that the tools optimized in this report will be useful in improving genome editing efficiency and specificity in plants and other organisms.


Subject(s)
Arabidopsis/genetics , CRISPR-Cas Systems/genetics , Mutagenesis/genetics , Base Sequence , Mutagenesis, Insertional/genetics , Mutation/genetics , Polymerase Chain Reaction , RNA Editing/genetics , RNA, Guide, Kinetoplastida/genetics , RNA, Transfer/genetics , Reproducibility of Results
6.
BMC Plant Biol ; 14: 327, 2014 Nov 29.
Article in English | MEDLINE | ID: mdl-25432517

ABSTRACT

BACKGROUND: To accelerate the application of the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/ CRISPR-associated protein 9) system to a variety of plant species, a toolkit with additional plant selectable markers, more gRNA modules, and easier methods for the assembly of one or more gRNA expression cassettes is required. RESULTS: We developed a CRISPR/Cas9 binary vector set based on the pGreen or pCAMBIA backbone, as well as a gRNA (guide RNA) module vector set, as a toolkit for multiplex genome editing in plants. This toolkit requires no restriction enzymes besides BsaI to generate final constructs harboring maize-codon optimized Cas9 and one or more gRNAs with high efficiency in as little as one cloning step. The toolkit was validated using maize protoplasts, transgenic maize lines, and transgenic Arabidopsis lines and was shown to exhibit high efficiency and specificity. More importantly, using this toolkit, targeted mutations of three Arabidopsis genes were detected in transgenic seedlings of the T1 generation. Moreover, the multiple-gene mutations could be inherited by the next generation. CONCLUSIONS: We developed a toolkit that facilitates transient or stable expression of the CRISPR/Cas9 system in a variety of plant species, which will facilitate plant research, as it enables high efficiency generation of mutants bearing multiple gene mutations.


Subject(s)
Arabidopsis/genetics , CRISPR-Cas Systems/genetics , Genetic Engineering/methods , Genome, Plant , Zea mays/genetics , Agrobacterium/genetics , Base Sequence , Genetic Vectors/genetics , Plants, Genetically Modified/genetics , Protoplasts/metabolism , Sequence Alignment
7.
Plant Commun ; 5(2): 100741, 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-37897041

ABSTRACT

Prime editing (PE) technology enables precise alterations in the genetic code of a genome of interest. PE offers great potential for identifying major agronomically important genes in plants and editing them into superior variants, ideally targeting multiple loci simultaneously to realize the collective effects of the edits. Here, we report the development of a modular assembly-based multiplex PE system in rice and demonstrate its efficacy in editing up to four genes in a single transformation experiment. The duplex PE (DPE) system achieved a co-editing efficiency of 46.1% in the T0 generation, converting TFIIAγ5 to xa5 and xa23 to Xa23SW11. The resulting double-mutant lines exhibited robust broad-spectrum resistance against multiple Xanthomonas oryzae pathovar oryzae (Xoo) strains in the T1 generation. In addition, we successfully edited OsEPSPS1 to an herbicide-tolerant variant and OsSWEET11a to a Xoo-resistant allele, achieving a co-editing rate of 57.14%. Furthermore, with the quadruple PE (QPE) system, we edited four genes-two for herbicide tolerance (OsEPSPS1 and OsALS1) and two for Xoo resistance (TFIIAγ5 and OsSWEET11a)-using one construct, with a co-editing efficiency of 43.5% for all four genes in the T0 generation. We performed multiplex PE using five more constructs, including two for triplex PE (TPE) and three for QPE, each targeting a different set of genes. The editing rates were dependent on the activity of pegRNA and/or ngRNA. For instance, optimization of ngRNA increased the PE rates for one of the targets (OsSPL13) from 0% to 30% but did not improve editing at another target (OsGS2). Overall, our modular assembly-based system yielded high PE rates and streamlined the cloning of PE reagents, making it feasible for more labs to utilize PE for their editing experiments. These findings have significant implications for advancing gene editing techniques in plants and may pave the way for future agricultural applications.


Subject(s)
Herbicides , Oryza , Oryza/genetics , Gene Editing , Alleles , Herbicides/pharmacology
8.
Article in Zh | MEDLINE | ID: mdl-24812834

ABSTRACT

OBJECTIVE: To clone and express Plasmodium falciparum erythrocyte membrane protein 1 DBLalpha (PfEMP1-DBLalpha) and three fragments genes, and screen the strongest affinity sequence with the red blood cell surface receptors-heparin or heparin sulfate in the structure of PfEMP1-DBLalpha. METHODS: The sequence of PfEMP1-DBLalpha1245 was optimized according to the characteristics of E. coli codon, synthesized, and divided into three fragments (DBLaA, DBLalphaB, and DBLalphaC) by PCR. Full-length gene and three gene fragments were subcloned into PGEX-4T-1 vector, and transformed into E. coli BL21 and then induced with IPTG for expression. The recombinant protein was purified from bacterial lysates using glutathione-Sepharose 4B. Heparin affinity test and glycosaminoglycan (GAG) inhibition test were used to analyze the affinity between recombinant protein and heparin. RESULTS: Four recombinant proteins(DBLalpha1245, DBLalphaA, DBLalphaB, and DBLalphaC) were expressed as solubility and the relative molecular weight (M(r) 73 600, M(r) 41 600, M(r) 42 500, and M(r) 41 500) were conformed to the prediction size. Heparin affinity test and GAG inhibition test showed that the four recombinant proteins were binded to the heparin-Sepharose, but not for the GST control. DBLalphaC (Q285-Y415) had the strongest affinity to heparin. CONCLUSION: The strongest affinity sequence with heparin or heparin sulfate in the structure of PfEMP1-DBLalpha is Q285-Y415, which plays a role in binding of Plasmodium falciparum infected red blood cells to the peripheral red blood cells.


Subject(s)
Erythrocytes/parasitology , Heparin/metabolism , Plasmodium falciparum/genetics , Protozoan Proteins/metabolism , Amino Acid Sequence , Gene Expression , Protein Binding , Protozoan Proteins/genetics , Recombinant Proteins/genetics , Recombinant Proteins/metabolism
9.
Plant Physiol ; 153(1): 41-51, 2010 May.
Article in English | MEDLINE | ID: mdl-20200068

ABSTRACT

We describe a highly efficient in vivo DNA assembly method, multiple-round in vivo site-specific assembly (MISSA), which facilitates plant multiple-gene transformation. MISSA is based on conjugational transfer, which is driven by donor strains, and two in vivo site-specific recombination events, which are mediated by inducible Cre recombinase and phage lambda site-specific recombination proteins in recipient strains, to enable in vivo transfer and in vivo assembly of multiple transgenic DNA. The assembly reactions can be performed circularly and iteratively through alternate use of the two specially designed donor vectors. As proof-of-principle experiments, we constructed a few plant multigene binary vectors. One of these vectors was generated by 15 rounds of MISSA reactions and was confirmed in transgenic Arabidopsis (Arabidopsis thaliana). As MISSA simplifies the tedious and time-consuming in vitro manipulations to a simple mixing of bacterial strains, it will greatly save time, effort, and expense associated with the assembly of multiple transgenic or synthetic DNA. The principle that underlies MISSA is applicable to engineering polygenic traits, biosynthetic pathways, or protein complexes in all organisms, such as Escherichia coli, yeast, plants, and animals. MISSA also has potential applications in synthetic biology, whether for basic theory or for applied biotechnology, aiming at the assembly of genetic pathways for the production of biofuels, pharmaceuticals, and industrial compounds from natural or synthetic DNA.


Subject(s)
Arabidopsis/genetics , Gene Transfer Techniques , Genes, Plant , Transformation, Genetic , Transgenes , Genetic Vectors , RNA Interference , Rhizobium/genetics
10.
Article in Zh | MEDLINE | ID: mdl-21823322

ABSTRACT

OBJECTIVE: To clone and express three VAR2CSA duffy antigen-binding ligand (DBL) domains (DBL4/ 5/6) encoded by var2csa gene of a Hainan isolate of Plasmodium falciparum, and study the difference of chondroitin sulfate A (CSA)-binding activity among them. METHODS: Three DBL domains was amplified by PCR and cloned into the vector pMD18-T. The recombinant plasmids were identified by enzyme digestion and sequencing, and then subcloned into the prokaryotic expression vector pET-22b. The recombinant plasmid was transformed into E. coli BL21 (DE3) and followed by expression of the protein induced by IPTG. The recombinant protein was purified with His GraciTrap kit and identified by SDS-PAGE and Western blotting. CSA-binding activity of the three recombinant DBL domains was assayed by ELISA. RESULTS: The target genes were amplified with the length of 996 bp, 859 bp and 894 bp. The constructed recombinant plasmids were identified by enzyme digestion and DNA sequencing. The recombinant proteins (DBL4/5/6) were purified, the relative molecular mass of DBLfA, DBL5 and DBL6 was Mr 439 800, Mr 34,500 and Mr 36,000, respectively. The purified protein has been confirmed with immunogenicity by Western blotting. The results of adhesion experiment indicated that A405 values of DBL5 domain with different concentration were significantly higher than that of DBLA and DBL6. CONCLUSION: The three recombinant proteins (DBLA/5/6) of VAR2CSA DBL domains were expressed, and DBL5 domain has high binding affinity with CSA.


Subject(s)
Antigens, Protozoan/genetics , Plasmodium falciparum/classification , Plasmodium falciparum/genetics , Protozoan Proteins/genetics , Receptors, Cell Surface/genetics , Recombinant Proteins/metabolism , Antigens, Protozoan/metabolism , Chondroitin Sulfates/metabolism , Cloning, Molecular , DNA, Protozoan/genetics , Escherichia coli/metabolism , Genetic Vectors , Plasmodium falciparum/metabolism , Protein Interaction Domains and Motifs , Protozoan Proteins/metabolism , Receptors, Cell Surface/metabolism , Recombinant Proteins/genetics
11.
Nephrol Ther ; 17(1): 30-34, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33203613

ABSTRACT

INTRODUCTION: Uremic pruritus is very common in hemodialysis or renal failure patients, there were lots of available treatments such as gabapentin, pregabalin, ondansetron, etc. However, there is no quantified study comparing these treatments together, it is impossible to conduct a clinical trial involving so many treatments, so we conduct a network meta-analysis to compare them. METHOD: We collected mean difference and standard error of visual analogue scale data as outcome. In total we collected 15 articles, 15 articles, 1180 subjects and 6 treatments included to this study. RESULTS: In these comparisons, gabapentin showed the largest effect MD: 5.19, 95%CI [3.77, 6.61], anti-histamine MD: 4.65, 95%CI [2.22, 7.07] and pregabalin MD: 4.62, 95%CI [2.71, 6.62] showed a similar effect. Opioid pathway related treatment also showed a significant but not so large effect MD: 2.45, 95%CI [0.41, 4.49]. Ondansetron and Doxepin didn't show a significant improvement among placebo, the overall quantifying heterogeneity I2=43.1%. There is no statically difference between gabapentin, pregabalin and anti-histamine treatments. CONCLUSIONS: So we conclude that gabapentin, pregabalin and anti-histamine has a similar efficacy on pruritus control.


Subject(s)
Uremia , Humans , Network Meta-Analysis , Pruritus/drug therapy , Pruritus/etiology , Randomized Controlled Trials as Topic , Renal Dialysis , Uremia/complications , Uremia/therapy
12.
Article in Zh | MEDLINE | ID: mdl-20806510

ABSTRACT

In the interaction of Plasmodium falciparum with human cells, sporozoite adheres to the receptor of the liver endothelial cell, then invades to liver. Merozoite binds to the surface of red blood cells, and invades to erythrocyte. The adhesion of membrane protein of the infected erythrocytes to the surface molecules of vascular endothelial cell in the vital organs leads to the obstruction of blood circulation eventually. The adhesion is mediated by interaction between parasite-derived ligands and the negative charged polysaccharides on the surface of host cells. This review is to discuss the molecular mechanisms in the host-parasite interactions.


Subject(s)
Host-Parasite Interactions , Plasmodium falciparum/pathogenicity , Polysaccharides , Protozoan Proteins , Animals , Carrier Proteins , Cell Adhesion , Endothelial Cells/parasitology , Hepatocytes/parasitology , Humans , Membrane Proteins
13.
Sci China Life Sci ; 63(10): 1491-1498, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32279281

ABSTRACT

Lack of appropriate methods for delivery of genome-editing reagents is a major barrier to CRISPR/Cas-mediated genome editing in plants. Agrobacterium-mediated genetic transformation (AMGT) is the preferred method of CRISPR/Cas reagent delivery, and researchers have recently made great improvements to this process. In this article, we review the development of AMGT and AMGT-based delivery of CRISPR/Cas reagents. We give an overview of the development of AMGT vectors including binary vector, superbinary vector, dual binary vector, and ternary vector systems. We also review the progress in Agrobacterium genomics and Agrobacterium genetic engineering for optimal strains. We focus in particular on the ternary vector system and the resources we developed. In summary, it is our opinion that Agrobacterium-mediated CRISPR/Cas genome editing in plants is entering an era of ternary vector systems, which are often integrated with morphogenic regulators. The new vectors described in this article are available from Addgene and/or MolecularCloud for sharing with academic investigators for noncommercial research.


Subject(s)
Agrobacterium/genetics , CRISPR-Cas Systems , Gene Editing , Genetic Vectors/genetics , Genome, Plant/genetics , Genome, Bacterial/genetics , Plant Development/genetics , Plant Proteins/genetics , Plants, Genetically Modified/genetics , Plants, Genetically Modified/growth & development , Plasmids/genetics
14.
Medicine (Baltimore) ; 99(23): e20609, 2020 Jun 05.
Article in English | MEDLINE | ID: mdl-32502035

ABSTRACT

BACKGROUND: The clinical effects and safety over the treatment of tibia intercondylar eminence fracture (TIEF) with cannulated screw and suture fixation were evaluated under arthroscope systematically, providing evidence-based medical support for the selection of surgical methods in terms of minimally invasive arthroscopic treatment for TIEF. METHODS: The English databases of PubMed, EMBASE, Cochrane Library, CNKI, SinoMed, VIP, and Wanfang databases were searched by computer. The randomized controlled trials were conducted to compare the clinical effects of TIEF with cannulated screw and suture fixation under arthroscope. The retrieval period is from the beginning of database building to January 2020. There is no language restriction. Chinese databases are searched by keywords, while English databases are searched by the combination of subject words and free words. According to the retrieval strategy, the two evaluators will lead the conforming documents into Note Express for repeated literature screening, and the two evaluators will extract and cross-check the conforming documents according to the pre-designed data extraction table. Two researchers adopted the modified Jadad scale independently to evaluate the quality of the literature. The RevMan 5.3 version software provided by the Cochrane Collaboration Network was adopted for statistical analysis. RESULTS: The study will strictly review and extract the data included in the literature, and scientifically make statistical analysis for the pre-set outcome indicators. All the research processes will be conducted in strict accordance with the guidance of system evaluation. In this study, the differences between cannulated screw fixation and suture fixation under arthroscopy will be evaluated by comparing the relevant outcome indicators. All the results of this study will be published openly in a highly influential professional academic journal. CONCLUSION: The paper adopted Cochrane system evaluation method to collect and sort out the published literature about the treatment of tibial eminence fracture between cannulated screw fixation and suture fixation under arthroscopy, and to compare the clinical efficacy and safety of the two fixation methods utilizing meta-analysis and comparison of related outcome indicators. Through this study, we will draw a positive conclusion, which will provide a basis for the better treatment of tibial eminence fracture. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42020168433.


Subject(s)
Fracture Fixation, Internal/methods , Knee Injuries/surgery , Tibial Fractures/surgery , Bone Screws , Humans , Meta-Analysis as Topic , Randomized Controlled Trials as Topic , Sutures , Systematic Reviews as Topic
15.
Genome Biol ; 21(1): 257, 2020 10 06.
Article in English | MEDLINE | ID: mdl-33023639

ABSTRACT

Prime editing is a novel and universal CRISPR/Cas-derived precision genome-editing technology that has been recently developed. However, low efficiency of prime editing has been shown in transgenic rice lines. We hypothesize that enhancing pegRNA expression could improve prime-editing efficiency. In this report, we describe two strategies for enhancing pegRNA expression. We construct a prime editing vector harboring two pegRNA variants for W542L and S621I double mutations in ZmALS1 and ZmALS2. Compared with previous reports in rice, we achieve much higher prime-editing efficiency in maize. Our results are inspiring and provide a direction for the optimization of plant prime editors.


Subject(s)
Acetolactate Synthase/genetics , Gene Editing/methods , Mutagenesis, Site-Directed/methods , RNA, Guide, Kinetoplastida/metabolism , Zea mays/genetics , Gene Editing/statistics & numerical data , Genetic Vectors , Plants, Genetically Modified , RNA, Guide, Kinetoplastida/genetics , Zea mays/enzymology
16.
Biochim Biophys Acta ; 1779(11): 655-62, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18620087

ABSTRACT

MicroRNAs (miRNAs), an endogenous type of small RNAs of approximately 22 nucleotides (nt), have long resided in the cells of plants and animals including humans, constituting an ancient pathway of gene regulation in eukaryotes. They have a simple structure in their mature form but carry enormous information that may regulate up to 90% of the human transcriptome. Furthermore, the multi-facets of a miRNA are tightly associated with diverse cellular proteins that make it broadly connected to various physiological and pathological processes. This review aims to examine miRNAs briefly from their biogenesis to their general functions with an emphasis on working mechanisms in regulation of their target mRNAs.


Subject(s)
Gene Silencing , MicroRNAs/metabolism , Animals , Humans , MicroRNAs/biosynthesis , Nuclear Proteins/metabolism
17.
Plant Mol Biol ; 71(1-2): 51-9, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19533381

ABSTRACT

MicroRNAs (miRNAs) are endogenous small RNAs of ~22 nucleotides (nt) that play a key role in down regulation of gene expression at the post-transcriptional level in plants and animals. Various studies have identified numerous miRNAs that were either up regulated or down regulated upon stress treatment. Here, we sought to understand the temporal regulation of miRNAs in different plant species under abscisic acid (ABA) and salt (NaCl) stress. Our results showed that the regulation of miR398 in response to ABA and salt stress was more dynamic in plants than previously reported. In poplars, miR398 was first induced upon 3-4 h of ABA or salt stress. However, this induction declined after 48 h and finally accumulated again over a prolonged stress (72 h). We referred to this kind of regulation as dynamic regulation. In contrast, such dynamic regulation of miR398 under salt stress was completely absent in Arabidopsis, in which miR398 was steadily and unidirectionally suppressed. Interestingly, ABA treatment caused a deviate dynamic regulation of miR398 in Arabidopsis, showing an opposite response as compared to that in poplars. We referred to the difference in regulation between Arabidopsis and poplars as differential regulation. Furthermore, the expression of the miR398 target, copper superoxide dismutase1 (CSD1), was in reverse correlation with the miR398 level, suggesting a control of this specific target expression predominantly by miR398 under abiotic stress. Together, these data consistently show a correlated regulation between miR398 and its representative target, CSD1, by ABA and salt stresses, and raise the possibility that regulation of miRNAs in plants is twofold: a dynamic regulation within a plant species and a differential regulation between different plant species.


Subject(s)
Abscisic Acid/pharmacology , Arabidopsis/genetics , Gene Expression Regulation, Plant/drug effects , MicroRNAs/genetics , Populus/genetics , RNA, Plant/genetics , Arabidopsis/metabolism , Kinetics , Plant Proteins/genetics , Populus/metabolism , Salts/pharmacology , Species Specificity , Superoxide Dismutase/genetics , Superoxide Dismutase-1
18.
Article in Zh | MEDLINE | ID: mdl-19459512

ABSTRACT

The Cryptosporidium parvum T7 phage display library was screened by using Caco-2 cells. Five specific gene fragments were identified by blasting sequences in GenBank, one of which encoding the CP2 protein was previously identified as a surface molecule of sporozoites and involved in parasite invasion. The others are hypothetic proteins with unknown functions. Bioinformatic analysis of these proteins indicated that they may be involved in the host-parasite interactions.


Subject(s)
Cryptosporidium parvum/genetics , Protozoan Proteins/genetics , Animals , Caco-2 Cells , Gene Library , Host-Parasite Interactions , Humans , Peptide Library
19.
DNA Cell Biol ; 27(5): 223-8, 2008 May.
Article in English | MEDLINE | ID: mdl-18419230

ABSTRACT

Apoptosis, which is usually accompanied by DNA degradation, is important not only for the homeostasis of metazoans but also for mammalian development. If DNA is not properly degraded in these processes, it can cause diverse diseases, such as anemia, cataracts, and some autoimmune diseases. A large effort has been made to identify these nucleases that are responsible for these effects. In contrast to Deoxyribonuclease I (DNase I), Deoxyribonuclease II (DNase II) has been less well characterized in these processes. Additionally, enzymes of DNase II family in Trichinella spiralis, which is an intracellular parasitic nematode, are also considered involved in the development of the nematode. We have compiled information from studies on DNase II from various organisms and found some nonclassic features in these enzymes of T. spiralis. Here we have reviewed the characterization and functions of DNase II in these processes and predicted the functions of these enzymes in T. spiralis during host invasion and development.


Subject(s)
Endodeoxyribonucleases/physiology , Immunity/physiology , Animals , Cell Proliferation , Humans , Trichinella spiralis/enzymology , Trichinella spiralis/pathogenicity
20.
J Biochem Mol Biol ; 40(6): 1083-9, 2007 Nov 30.
Article in English | MEDLINE | ID: mdl-18047807

ABSTRACT

The HAP complex has been found in many eukaryotic organisms. HAP recognizes the CCAAT box present in the promoters of 30% of all eukaryotic genes. The HAP complex consists of three subunits--HAP2, HAP3 and HAP5. In this paper, we report the biological function of the AtHAP3b gene that encodes one of the HAP3 subunits in Arabidopsis. Compared with wild-type plants, hap3b-1 and hap3b-2 mutants exhibited a delayed flowering time under long-day photoperiod conditions. Moreover, the transcription levels of FT were substantially lower in the mutants than in the wild-type plants. These results imply that AtHAP3b may function in the control of flowering time by regulating the expression of FT in Arabidopsis. In a subsequent study, AtHAP3b was found to be induced by osmotic stress. Under osmotic stress conditions, the hap3b-1 and hap3b-2 mutants flowered considerably later than the wild-type plants. These results suggest that the AtHAP3b gene plays more important roles in the control of lowering under osmotic stress in Arabidopsis.


Subject(s)
Arabidopsis Proteins/physiology , Arabidopsis/physiology , CCAAT-Binding Factor/physiology , Arabidopsis/genetics , Arabidopsis/growth & development , Arabidopsis Proteins/genetics , Base Sequence , CCAAT-Binding Factor/genetics , DNA Primers/genetics , DNA, Bacterial/genetics , DNA, Plant/genetics , Flowers/growth & development , Flowers/physiology , Gene Expression Regulation, Developmental , Gene Expression Regulation, Plant , Genes, Plant , Genetic Complementation Test , Mutagenesis, Insertional , Osmotic Pressure , Phenotype , Photoperiod , Plants, Genetically Modified
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