40results about How to "Silent efficiency is high" patented technology

The invention provides a bone-targeted delivery system for osteogenesis treatment based on small nucleic acid medicine, and a preparation method thereof. The bone-targeted delivery system comprises liposome, bone-targeted molecules and small nucleic acid medicine, wherein the bone-targeted molecules are one or more selected from bisphosphonate, eight aspartic acid polypeptide repeat sequences, six aspartic acid-serine-serine polypeptide repetitive sequences and screened out aptamer aiming at osteoblastlike cells; and the small nucleic acid medicine is one or more selected from blocking agents of small interfering ribonucleic acid, micro ribonucleic acid mimics and micro ribonucleic acid which have the function of promoting bone formation. Compared with conventional bone-targeted delivery systems, the bone-targeted delivery system has stronger specificity and high transfection efficiency for the small nucleic acid, and can reach relatively high silencing efficiency.

The invention discloses a tobacco squalene synthase?protein, the?amino acid sequence?of which is as shown in SEQIDNO: 1. Tobacco squalene synthase?gene (i) NtSQS (/i) is a?key regulatory gene?in tobacco sterol synthesis pathway?and has a specific high expression level in?tender?tissue.?Virus mediated?gene silencing?vector TRV-NtSQS which is constructed is?inoculated to?Ben's tobacco?so as to obtain a plant with high efficiency of silence. By detection of?phytosterol?content in?Ben's tobacco, the phytosterol?content in the?gene silencing?plant is found to be?observably?decreased?by 41.26%. The above?phenomenon?indicates that?the sterol content?in a plant can be significantly reduced by silencing?the gene. Tobacco squalene synthase?gene (i) NtSQS (/i) is the?key regulatory genein tobacco sterol synthesis pathway, can be used to adjust the sterol content?in tobacco and contributes to?genetic engineering breeding?of low sterol?high quality tobacco.

The invention belongs to the technical field of cotton breeding, and specifically relates to a gene silencing method in early germination and seedling stage of cotton. The method comprises the steps of preparing agrobacterium liquid for transfection, performing virus amplification by utilizing tobacco, infecting cotton seeds and the like. According to the invention, a cotton gene silencing technology is optimized and improved by taking a tobacco rattle virus (TRV) as a virus vector. It is proved by a result that a gene silencing phenotype can be obtained through inoculating cotton cotyledon orseeds with TRV homogenate or agrobacteria. Through comparing the similarities and differences of TRV homogenate and agrobacteria inoculation, it is discovered that through applying a seed imbibition(Si) method to inoculation of any infection liquid, the virus inoculation time can all be advanced to the inflorescence primordial formation stage of the seeds; functional genes during germination ofthe seeds can be efficiently silenced within 3 days; virus homogenate-mediated gene silencing can last till the seedling stage of the cotton. Si-VIGS (Seed imbibition-virus-induced gene silencing) involved in the invention can efficiently silence the genes from the early germination stage of the cotton; the operation is simple; the phenotypes are unified; a relatively good application prospect isshown.

Belonging to the fields of functional material loaded drugs and gene technologies, the invention discloses a composite material of a functional mesoporous silica loaded drug and siRNA, a preparation method and application thereof in preparation of anticancer drugs. The composite material is prepared by the method comprising the steps of: adding mesoporous silica into a 3-mercaptopropyl trimethoxysilane solution, conducting heating reaction and separation to obtain thiolated mesoporous silica, dispersing the thiolated mesoporous silica into a 2, 2-dithiodipyridine solution, and carrying out heating reaction to obtain disulfide bond modified mesoporous silica, adding the disulfide bond modified mesoporous silica into a doxorubicin water solution, then adding thiolated siRNA, and conducting separation, thus obtaining the composite material of the functional mesoporous silica loaded drug and siRNA. The composite material provided by the invention can be applied to preparation of anticancer drugs, can load drugs into cells, significantly improves the enrichment amount of drugs in cells, plays a good mesopore blocking role, and reaches the effect of silencing gene when released in cells.

The invention discloses a toxoptera citricida chitin synthase gene. The sequence of the toxoptera citricida chitin synthase gene is shown as SEQ ID NO:3. The invention further discloses dsRNA of the toxoptera citricida chitin synthase gene, and the sequence of the dsRNA is shown as SEQ ID NO:6. The invention further discloses a synthesis method of the dsRNA of the toxoptera citricida chitin synthase gene. The synthesis method includes the following steps that total RNA of toxoptera citricida is extracted and subjected into reverse transcription to form cDNA serving as an amplification template; PCR amplification is carried out through primers with the sequences of SEQ ID NO:4 and SEQ ID NO:5, a product is recycled after electrophoresis, and the dsRNA of the toxoptera citricida chitin synthase gene is synthesized with a gel recycling product as a template. According to the dsRNA of the chitin synthase gene, gene silencing efficiency is high, toxoptera citricida has obvious phenotypic changes after gene interference, and the good application prospects are achieved in the aspect of researching and developing novel pesticide.

The invention discloses a branched polyetherimide material containing a ketone thioacetal bond, as well as a preparation method and application thereof. The preparation method comprises the followingsteps: (1) stirring acetone and acid containing thiol to react at room temperature; (2) adding polyetherimide and an activator after the reaction is finished, dissolving in an organic reagent, stirring to react, bonding chlorin e6 and carboxyl polyethylene glycol through an amidation reaction to obtain the reactive oxygen sensitive branched polyetherimide material containing the ketone thioacetalbond. The branched polyetherimide material has excellent biocompatibility and degradability, is entrapped with siRNA, and forms nano-particles by self-assembly, can generate a great number of reactiveoxygen under excitation of a light source with specific wavelength to destroy the structure of endosome, the reactive oxygen sensitive ketone thioacetal bond is broken, particles are disintegrated, and endosome escape and release of intracellular siRNA can be accelerated. The branched polyetherimide material containing a ketone thioacetal bond has a huge clinical application potential in the field of tumor treatment.

The invention relates to a method for gene function identification of orange panonychus citri. The method comprises the following steps: (1) preparing a target gene dsRNA liquid: synthesizing a corresponding dsRNA liquid according to a target gene to be inhibited; (2) preparing a leaf disc by using an orange leaf and washing; (3) drying the leaf disc until the leaf disc obviously shrinks, containing the dsRNA liquid prepared in the step 1 by using a centrifugal tube cover, and floating the leaf disc on the dsRNA liquid until the leaf disc is recovered to the original shape and does not shrink; (4) putting the orange panonychus citri on the floating leaf disc, putting the leaf disc in an incubator and culturing for 60 to 80 hours at a condition that the temperature is 22 to 28 DEG C, the humidity is 55% to 65% and the illumination to darkness ratio is 14h:10h; (5) after the culture is ended, collecting orange panonychus citri bodies, extracting RNA, and detecting the expression condition of the target gene provided in the step 1. The method disclosed by the invention can be used for solving the problem that no effective dsRNA introduction method is provided for the orange panonychus citri at present.

The invention discloses application of a fermented extract of a sea-buckthorn endophyticfungi strain SJ1. The application comprises induction of accumulation of plant endogenous salicylic acid (SA), enhancement of efficiency of plant RNA silencing and improvement of resistance of plants to viruses. The fermented extract of the sea-buckthorn endophyticfungi strain SJ1 provided by the invention hasrelatively good preventive effects when the use concentrations are 150 ng/mL and 100 ng/mL, the average preventive effects are 77.45% and 72.88% respectively which are both higher than the preventiveeffect (71.98%) of control 5 ug/mL of 20% moroxydine cupric acetate; according to comprehensive analysis, the use concentration cost of 100-150 ng/mL of the SJ1 fermented extract is lower than that ofthe 20% moroxydine cupric acetate, and the SJ1 fermented extract provided by the invention is more economical in use.

The invention provides siRNA for inhibiting an HMGB1 gene, a stable nucleic acid lipid nanoparticle containing the siRNA, and an application of the siRNA and the stable nucleic acid lipid nanoparticle. The positive-sense strand of an siRNA molecule is SEQ ID NO:1, and the antisense chain is SEQ ID NO:2. The technical effects are as follows that the siRNA aiming at the HMGB1 is encapsulated in thestable nucleic acid lipid nanoparticle, so that the siRNA is prevented from being degraded by in-vivo enzymes; the prepared nanoparticle has a significant anti-inflammatory effect; and the siRNA aiming at the HMGB1 can be targeted and delivered to liver macrophages for release to enhance the anti-inflammatory effect, so that non-alcoholic steatohepatitis (NASH) can be better treated.

The invention discloses a virus-induced turnip gene silencing system and application thereof. The invention provides a method for silencing a target gene in turnip. The method comprises the following steps of: (1) designing an interference sequence according to the target gene and a specific principle; (2) preparing an interference vector, wherein a starting vector of the interference vector is a pTY-S vector, and the interference vector has the interference sequence obtained in the step (1) and a reverse complementary sequence thereof; and (3) rubbing leaves of a turnip plant to make a wound, and then inoculating the interference vector. The virus-induced turnip gene silencing system has the beneficial effects that agrobacterium transfection is not needed, and complex steps such as gene gun bombardment are omitted; and the turnip virus-induced gene silencing system is established, simple rubbing inoculation is adopted, the duration is short, the operation is simple, the damage to plants is small, the silencing efficiency is greatly improved, and silencing phenotypes of a plurality of organs can be observed at the same time. The virus-induced turnip gene silencing system has important significance for variety improvement of brassica crops.

The invention discloses a toxoptera citricidus kirkaldy Hunchback gene, the sequence of which is shown in SEQ ID NO: 3; the invention also discloses dsRNA of the Hunchback gene, the sequence of whichis shown in SEQ ID NO: 6; the invention also discloses a synthesis method of dsRNA of the toxoptera citricidus kirkaldy Hunchback gene, which comprises the following steps of: extracting total RNA, performing reverse transcription to obtain cDNA, performing PCR amplification by using the primer of SEQ ID NO: 4 and the primer of SEQ ID NO: 5, performing electrophoresis on PCR amplification products, recovering products, and performing template synthesis by using gel recovery products to obtain dsRNA. The invention also discloses a novel aphid RNAi method, which comprises the following steps of:fixing backs of toxoptera citricidus kirkaldy upwards, dripping dsRNA of the Hunchback gene on backs of abdomen of toxoptera citricidus kirkaldy, and putting toxoptera citricidus kirkaldy into a culture box for feeding after dsRNA liquid is fully absorbed to surfaces of toxoptera citricidus kirkaldy bodies and become dry.