Abstract: The objective of this study was to construct a targeting vector for knocking-out bovine myostatin (MSTN) gene. Based on the bovine MSTN gene sequence, we chose third exon about 600 bp as a target site. The homologous arms of bovine MSTN gene were amplified from the genomic DNA, which were about 4.4 and 1.4 kb in length, respectively. The two fragments were cloned into pPNTⅢ vector and located at both sides of the neomycin resistance gene to construct targeting vector MSTN-KO-pPNTⅢ. By sequence analysis and restricted endonucleases digestion, the 1.4 kb short arm and 4.4 kb long arm were detected in the targeting vector. In conclusion, the replacement targeting vector for bovine MSTN gene had been successfully constructed.

Key words:

bovine; myostatin gene; homologous arms; gene targeting