7 results about "Spontaneous mutation" patented technology

The invention belongs to the technical field of biology and new medicine, and discloses a method for constructing a myxobacteria expression chassis with genetic stability and application of the myxobacteria expression chassis. Through gene deletion and overexpression analysis, it is verified that the spontaneous mutation rate of a strain can be reduced by deletion of a TLS pathway and overexpression of RecA, and a myxobacteria strain 2K7 with genetic stability is further constructed on the basis. The spontaneous mutation rate of the new strain is reduced by 11.5 times, and the transformation capability of growth plasmids of the strain is obviously improved. According to the research, the genetic stability of the myxobacteria is improved for the first time through a repair way after modification and replication, and the research method and the research result are innovative.

The present invention provides a method for constructing an inbred mouse model by introducing a group of spontaneously mutated Hr genes and its application. The method is to introduce the target gene into the inbred strain by homologous introduction to obtain a new gene introduction animal model. First, the ICR-Hr from the outbred group with strong genetic polymorphism is introduced. hr (Trade name: SHJH hr ) were introduced into the inbred BALB / cAShjh mice to establish the BALB / cA.Cg.ICR‑Hr hr / Shjh mice, and then continued to be introduced into the inbred C57BL / 6JShjh mice to establish C57BL / 6J.Cg.BALB / cA-Hr hr / Shjh, thereby establishing a homologous introduction inbred line, each introduction needs to be repeated for 10 or more consecutive generations, and repeated backcrossing allows the recipient strain to replace the chromosomes of the donor strain with the chromosomes other than the chromosome region carrying the Hr allele, so that related applications can continue to be studied on the characteristics of each strain.

The present application belongs to the field of metabolic engineering, and particularly relates to a genetically engineered strain for producing L-homoserine, a preparation method and application thereof. The present application utilizes directed evolution, and through continuous enrichment of spontaneous mutation of homoserine-producing bacteria SH017, a strain SHD275 for efficiently fermenting and producing L-homoserine is screened. The fermentation yield and sugar conversion rate of the production strain are both higher than those of the original strain SH017, thereby greatly saving the production cost.

The twitcher mouse model is a main animal model for researching the pathogenesis and treatment method of GLD disease at present, and the model is caused by a spontaneous mutation of a C57BL / 6 mouse model GALC At present, a commonly used genotype identification method is time-consuming and expensive. In order to overcome the defect, the special identification primer is designed, the PCR method is adopted, and the restriction endonuclease Eco RV is used for single enzyme digestion verification, so that a rapid, efficient and economic genotype identification method is established, and a reference for the genotype identification of the twitcher mouse is provided.

The present invention provides a spontaneous mutation detection method capable of accurately detecting a low-frequency DNA chain base spontaneous mutation. A spontaneous mutation detection method according to the present invention comprises: a waveform data acquisition step (S101) for acquiring waveform data including at least base sequence information and peak waveform appearance position information, by using a plurality of reference DNA samples that do not contain a mutation; a noise model data creation step (S102) for creating noise model data using a set of peak waveforms of the waveform data of the plurality of reference DNA samples; a test data acquisition step (S103) for acquiring test data that is waveform data of the test sample; an alignment step (S104) for comparing the noise model data with the test data base sequence and aligning the test data with respect to the noise model data so as to pair the same bases with one another; and an exclusion step (S105) for excluding a peak waveform which appears at the same position as the noise model data from among the peak waveforms in the test data.

The invention relates to bacillus subtilis with reduced spontaneous mutation rate and application thereof, and belongs to the technical field of gene engineering. According to the invention, the bacillus subtilis with reduced spontaneous mutation rate is constructed by knocking out genes yolk D, yozK and yozL for coding potential error-prone DNA polymerase in a bacillus subtilis genome under the condition that the specific growth rate of the strain is not influenced, and the bacillus subtilis can be applied to improving the expression stability of free or integrated expression exogenous genes. The strain is used as a chassis strain, and an N-acetylneuraminic acid synthesis pathway is constructed in an integrated expression manner, so that N-acetylneuraminic acid can still be efficiently produced after 59 generations of passage. The strain is used as a chassis strain to construct plasmids for expressing fluorescence reporter genes, and the correct replication of genes on the plasmids can be ensured to exceed 47 generations under the condition that the plasmids are not lost. The bacillus subtilis provided by the invention provides an efficient universal tool for improving genetic stability, and can be applied to construction of cell factories with stable expression.

Provided are an engineered halophilic microorganism and a construction method and use therefor. By means of knockout or knockdown of one or more than two genes on a transposon and encoding a transposase, a stable halophilic microorganism is obtained, which has good growth condition, can stably synthesize polyhydroxy alkanoates, and can effectively avoid spontaneous mutation of the strain.