Method for preparing beef cattle with double muscled similar to naturally mutated Belgian blue cattle

Abstract

The invention discloses a method for preparing beef cattle with double muscled similar to naturally mutated Belgian blue cattle. The invention provides a method for preparing MSTN biallelic mutant cells, which comprises the following steps of: performing genome editing on a target region of a first exon of an MSTN gene biallelic of a bovine in vitro fibroblast genome, so that an exon 1 forms a termination codon in advance to terminate expression; obtaining an MSTN biallelic mutant cell; the invention establishes a method for preparing (MSTN-4 / -4) knockout cattle without any exogenous DNA integration and with double MSTN allele small fragment deletion. Importantly, the cattle have a very similar double muscled phenotype with naturally existing Belgian blue cattle.

Description

technical field [0001] The invention belongs to the field of biotechnology, and in particular relates to a method for preparing double-muscle rump cattle similar to natural mutant Belgian blue cattle. Background technique [0002] With the continuous attention and strong support of the Chinese government to agricultural issues, my country's agricultural development has made great progress, especially the rapid development of the animal-related animal husbandry industry, which has greatly improved people's living conditions and dietary structure . Practices at home and abroad have shown that in the development of animal husbandry, the contribution rate of breeds has reached more than 40%. Therefore, animal breeding technology plays a vital and even irreplaceable role in promoting animal husbandry and even agricultural development. However, in my country, the main animal husbandry breeds are heavily dependent on imports. Among the main animal husbandry breeds, the dependence o...

AI Technical Summary

Problems solved by technology

[0005] Although the mechanism is known, it is difficult to simulate and prepare this kind of "double-muscled hip" cattle through traditional gene targeting technology.

First, the efficiency of monoallelic knockout of MSTN by traditional gene targeting in cattle is very low, and biallelic knockout of MSTN is even more difficult

Second, at the same time, traditional gene targeting technology will introduce screening marker genes, which are very different from the natural double-muscle rump cow genome, and screening marker genes will cause biosafety problems

Third, it is difficult to obtain natural mutations such as pure 11bp or single-base mutations through traditional gene targeting technology.

[0006] With the continuous development of artificial nucleases (ZFNs / TALENs / Cas9), the biallelic gene knockout technology in large animals has been greatly improved, and many MSTN gene knockout animals have also appeared. However, there are still many problems in these studies. First, There are also screening marker genes or artificial nuclease genes; second, the size and type of deletion of the two biallelic genes are different, which cause multiple transcripts in animals, affecting functional research and the animals themselves

These may be one of the reasons why there is no large animal with normal MSTN gene knockout

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