A promoter trap vector for knocking out bovine myostatin gene with high targeting efficiency

Genet Mol Res. 2015 Mar 31;14(1):2750-61. doi: 10.4238/2015.March.31.5.

Abstract

With the development of gene targeting approaches, genomic mutation technologies in livestock animals such as gene trapping, zinc finger nucleases (ZFNs), transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats and their associated systems have been improved. Although ZFNs have been used for gene targeting in many species, the off-target sites are still present. Using gene trapping, the workload of screening of targeted clones was decreased by generating a smaller number of drug-resistant clones. Determining whether the efficiency of gene trapping is lower than that of ZFNs for a specific gene has been challenging. In this study, to knock out the bovine myostatin gene, we constructed a promoter trap vector and compared its efficiency with that of ZFNs. The promoter trap vector contained a green fluorescent protein sequence without the promoter and a neomycin phosphotransferase (neo(R)) cassette driven by the phosphoglycerate kinase promoter. When the trapping vector was inserted downstream of the endogenous promoter, the fluorescent protein gene was expressed. The targeted-positive cell clones were identified based on green fluorescence and G418 double selection, followed by polymerase chain reaction analysis and sequencing. The targeting efficiency reached 5%. Compared with the efficiency of ZFN pairs (5.17 and 2.86%), the promoter trap vector PIII-myostatin could knock out the bovine myostatin gene. Therefore, gene trapping may be an effective tool for genomic modification.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cattle
  • Cells, Cultured
  • Endonucleases / genetics
  • Endonucleases / metabolism
  • Fetus
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Gene Knockout Techniques / methods*
  • Gene Targeting / methods*
  • Genetic Vectors / genetics*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Kanamycin Kinase / genetics
  • Kanamycin Kinase / metabolism
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Muscles
  • Myostatin / genetics*
  • Promoter Regions, Genetic / genetics*
  • Transfection
  • Zinc Fingers / genetics

Substances

  • Myostatin
  • Green Fluorescent Proteins
  • Kanamycin Kinase
  • Endonucleases