38 results about "Spontaneous mutation" patented technology

A method for determining mutation load in a somatic cell is determined by mutation analysis of the p53 gene. The p53 gene has been found to be a useful indicator of predisposition to spontaneous mutations or prior carcinogen exposure. Cells that contain mutated p53 tend to accumulate the mutant protein. Thus, DNA from a cell identified by p53 accumulation is amplified and the amplification product further analyzed for mutations in the p53 gene.

The invention relates to a method for separating and detecting a spontaneous mutation gene based on agarose gel denaturation and renaturation and biotin affinity adsorption, which belongs to the technical field of biology, and relates to a method for separating and detecting a mutation gene. The method comprises the following steps of: marking wild deoxyribonucleic acid (DNA) fragments by using biotin, mixing the biotin-marked wild DNA fragments and DNA fragments to be detected, and performing denaturation and renaturation, wherein at the moment, DNA fragments which contain mutation sites cannot form heteroduplex DNA molecules because the biotin-marked wild DNA fragments with the same migration rate as the DNA fragments are not hybridized with the DNA fragments, DNA fragments which do notcontain the mutation sites are hybridized with the corresponding biotin-marked wild DNA fragments to form the heteroduplex DNA molecules, and the heteroduplex DNA molecules carry biotin marks; and adsorbing and recovering the molecules which carry the biotin marks by using streptavidin magnetic beads to separate the DNA fragments which contain the mutation sites. Compared with the conventional method, the method is simpler and more convenient and sensitive, can be used for accurately identifying and detecting the mutation sites, and has high reliability.

A natural yeast extract which is rich in glutamic acid and therefore has an impact at first taste. Further, provided is a yeast extract which is also rich in 5′-guanylic acid or 5′-inosinic acid and therefore has strong umami. Further, provided is a yeast mutant capable of accumulating a large amount of glutamic acid, glutamine and ribonucleic acid for obtaining such a yeast extract. A yeast mutant to which resistance to organic acids and analogues thereof has been imparted by inducing spontaneous mutation, accumulates a significant amount, i.e., 10% by weight or more of the total of free glutamic acid and glutamine in the cell, and further accumulates 5% by weight or more of a ribonucleic acid. The yeast extract produced by using this strain contains 20% by weight or more of L-glutamic acid, and further contains 3% by weight or more of 5′-IG.

The invention concerns methods for the development of mutant animals, including genetically engineered animals and those carrying spontaneous mutations, as human disease models. In particular, the invention provides an integrated technology, including rigorous specifications and quality control, for the development of animal models that can serve as a living assay system, useful in biomedical research and in the development of human therapeutics.

The invention discloses a multiplex-PCR detection method for a single sperm. The method comprises the steps that A, sperms are pretreated; B, micromanipulation is performed to pick up a single sperm; C, the sperm is subjected to multiplex-PCR detection. The multiplex-PCR detection method for a single sperm breaks through the limitation, only targeting female eggs and embryos, of past genetic disease gene detection on micro-cells and makes it possible for analysis of whether a male germ cell is a chimera. Through the method, very rare spontaneous mutation which only exists in a single sperm and cannot be detected in a somatic cell or sperm groups can be detected, auxiliary diagnosis analysis of de novo mutation can be performed on a paternal age effect series genetic disease caused by de novo mutation of a paternal germ cell, and on this basis, the risk of birth of a child patient with the genetic disease can be prevented and interdicted in combination with the preimplantation genetic diagnosis technology.

The invention belongs to the technical field of plant genetic engineering, and particularly relates to rapid mapping and cloning method for plant spontaneous mutation genes bridged by a neutral mutant. The invention aims to overcome the defects in the prior art, and the neutral mutant produced by mutagenesis of an ethylmethane sulfonate (EMS) mutagenic agent composition is utilized to rapidly mapthe spontaneous mutation genes. Under the same genetic background, the neutral mutant (namely, no macroscopic phenotypic variation) produced by mutagenesis of the EMS mutagenic agent composition is hybridized with a spontaneous mutant to obtain F1, and selfing is continued to obtain an F2 generation. By performing screening and hybrid sequencing of extremely recessive phenotypic single plants in an F2 population, combining with EMS mutated neutral mutant sequencing data, and utilizing a bioinformatics method, the mutation genes are rapidly mapped. Compared with known methods, the rapid mappingand cloning method has the outstanding advantages of high screening efficiency, short consumed time, low cost and the like. The rapid mapping and cloning method can be used for rapid cloning of the spontaneous mutation genes.

The invention discloses a plasmid for improving spontaneous mutation frequency of bacillus subtilis. The plasmid is selected from any one of a PUS20D9M, a PUS20XP1 and a PUS20XP2; wherein the plasmid pUS20D9M has a sequence as shown in SEQ ID NO. 1, the plasmid pUS20XP1 has a sequence as shown in SEQ ID NO. 2, and the plasmid pUS20XP2 has a sequence as shown in SEQ ID NO. 3. Bacillus subtilis is an important microorganism. Many breeding works need to improve gene mutation frequency of bacillus subtilis. However, an ideal method for controlling spontaneous mutation frequency of bacillus subtilis does not exist at present. According to the invention, by virtue of a CRISPRi technology and a method for overexpressing error-prone DNA polymerase, the spontaneous mutation frequency of a host is improved (as high as 5128 times). The whole operation can be realized through transformation and elimination of plasmids, and gene knockout of a host is not needed.

The invention belongs to the technical field of biology, and particularly relates to a genetic manipulation method for manually controlling a spontaneous mutation rate of bacillus subtilis and application thereof. The genetic manipulation method comprises the following steps: regulating and controlling an operon MutSL which is responsible for a mismatch repair system of the bacillus subtilis by axylose induced promoter and repressor protein, and establishing recombinant plasmids in corresponding inducible expression; integrating the recombinant plasmids to a bacterial strain genome by utilizing Spizizen double exchange, and carrying out positive-negative selection, thus obtaining objective engineering strains; regulating different expression levels of the operon MutSL of the mismatch repair system through different xylose addition concentration, thus realizing manual control on the spontaneous mutation rate of the bacillus subtilis.

The invention discloses a gene editing tool, a preparation method thereof and a multi-round gene editing method, and belongs to the technical field of gene engineering. The problem that an existing multi-round gene editing method wastes time and labor is solved. The invention provides a gene editing tool, which comprises the following three sgRNA expression parent plasmids: pRock series mother plasmids, pPaper series mother plasmids and pScissors series mother plasmids, wherein each mother plasmid can express sgRNA used for editing a target gene and can also express sgRNA targeting one of theother two mother plasmids. In the process of implementing gene editing, when the gene editing plasmids constructed by the three mother plasmids are recycled, the gene editing plasmids which are firstly used in host cells or the selection markers are eliminated by the gene editing plasmids which are later used. According to the method, the editing period is shortened, the multi-round gene editing speed is increased, and the possibility of spontaneous mutation of the genome can be reduced due to fewer culture times.

A new and distinct variety of climbing shrub rose plant is provided. The new plant is a spontaneous mutation of unknown causation of the ‘Meiviolin’ variety (U.S. Plant Pat. No. 6,892). Attractive near white long-lasting very double blossoms having an ancient rose configuration are formed on a substantially continuous basis. Vigorous medium green semi-glossy foliage is formed that contrasts well with the near white blossom coloration. Good resistance to Black Spot and good tolerance to frost are displayed. The new variety is particularly well suited for providing attractive ornamentation in the landscape. It can be grown to advantage on a trellis, lamppost or gazebo.