Kit for breeding a TGEV infection resistant pig and use thereof

A method for constructing a cell with site-directed modification of a porcine aminopeptidase N (pAPN) gene, which comprises the following steps:

• introducing a kit comprising a genetically edited protein of Cas9, pAPN-sgRNA-1,pAPN-sgRNA-2, and a donor DNA, wherein the pAPN-sgRNA-1 and pAPN-sgRNA-2 target two different target sequences of the pAPN gene set forth in SEQ ID NO. 1 and SEQ ID NO. 2;
• and a fragment between the two different target sequences of SEQ ID NO. 1 and SEQ ID NO. 2 is designated as a fragment to be site-directed modified, which comprises a codon encoding tryptophan at position 737 in a pAPN protein;
• and the donor DNA contains a fragment with site-directed modification, which is obtained by mutating a codon encoding tryptophan at position 737 in the pAPN protein to a codon encoding alanine in the fragment to be site-directed modified or a set of vectors comprising a vector expressing the kit into porcine ileal epithelial cells or porcine fibroblasts to obtain the cell with site-directed modification of the pAPN gene;
• wherein the donor DNA is double stranded DNA set forth in SEQ ID NO. 3.