SgRNA and transgenic expression vector, expression strain and screening method of expression strain

Abstract

The invention belongs to the technical fields of bombyx mori gene engineering and artificial breeding, and discloses sgRNA, a transgenic expression vector, an expression strain and a screening methodof the expression strain. A CRISPR/Cas9 system is used, a strain expressing the sgRNA used for knocking out let-7Complex/Cluster (let-7C) is established firstly, the strain is hybridized with a specific cas9 expressing strain, and let-7C in silk gland of bombyx mori is knocked out; the sgRNA expressing strain and the middle silk gland and rear silk gland Cas9 expression strains are hybridized to obtain a strain having let-7C specifically knocked out at the middle silk gland and a strain having let-7C specifically knocked out at the rear silk gland. The silk gland let-7 of bombyx mori is knocked out through the CRISPR/Cas9, the development of the silk glands can be promoted, the expression of silk protein is increased and the silk yield of bombyx mori is increased.

Description

technical field [0001] The invention belongs to the technical field of artificial mutation breeding, and in particular relates to a sgRNA and a transgene expression carrier, an expression strain, and a screening method, specifically the sgRNA of let-7microRNA complex / cluster and its transgene expression carrier, and the knockout of let-7complex / cluster Strain screening method. Background technique [0002] Commonly used traditional breeding methods include artificial mutagenesis and cross breeding. Artificial mutation breeding refers to the use of chemical mutagenesis or physical mutagenesis to treat organisms to induce mutations in biological genetic traits and to screen out valuable mutants. Although artificial mutagenesis has increased the frequency of genetic trait variation, the induced mutation is not directional, and there are few beneficial mutations. The breeding process needs to deal with a large number of mutant varieties or materials, and the workload is heavy. ...

AI Technical Summary

Problems solved by technology

However, microRNA is different from protein-coding genes. There is no triplet genetic code, and frameshift mutations cannot occur. The loss or mutation of a single base is probably not enough to affect the production of microRNA. It is best to delete the entire microRNA on the genome. mature sequence

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