Production of α1,3-galactosyltransferase and cytidine monophosphate-N-acetylneuraminic acid hydroxylase gene double-deficient pigs by CRISPR/Cas9 and handmade cloning

J Reprod Dev. 2017 Feb 16;63(1):17-26. doi: 10.1262/jrd.2016-079. Epub 2016 Oct 8.

Abstract

Gene-knockout pigs hold great promise as a solution to the shortage of organs from donor animals for xenotransplantation. Several groups have generated gene-knockout pigs via clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) and somatic cell nuclear transfer (SCNT). Herein, we adopted a simple and micromanipulator-free method, handmade cloning (HMC) instead of SCNT, to generate double gene-knockout pigs. First, we applied the CRISPR/Cas9 system to target α1,3-galactosyltransferase (GGTA1) and cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) genes simultaneously in porcine fetal fibroblast cells (PFFs), which were derived from wild-type Chinese domestic miniature Wuzhishan pigs. Cell colonies were obtained by screening and were identified by Surveyor assay and sequencing. Next, we chose the GGTA1/CMAH double-knockout (DKO) cells for HMC to produce piglets. As a result, we obtained 11 live bi-allelic GGTA1/CMAH DKO piglets with the identical phenotype. Compared to cells from GGTA1-knockout pigs, human antibody binding and antibody-mediated complement-dependent cytotoxicity were significantly reduced in cells from GGTA1/CMAH DKO pigs, which demonstrated that our pigs would exhibit reduced humoral rejection in xenotransplantation. These data suggested that the combination of CRISPR/Cas9 and HMC technology provided an efficient and new strategy for producing pigs with multiple genetic modifications.

MeSH terms

  • Alleles
  • Animals
  • Animals, Genetically Modified / genetics
  • Animals, Newborn
  • Antibodies / chemistry
  • CRISPR-Cas Systems*
  • Cloning, Molecular
  • Cumulus Cells / metabolism
  • Fibroblasts / metabolism
  • Galactosyltransferases / genetics*
  • Gene Knockout Techniques
  • Genotype
  • Immunoglobulin G / chemistry
  • Leukocytes, Mononuclear / cytology
  • Mixed Function Oxygenases / genetics*
  • Nuclear Transfer Techniques
  • Oocytes / cytology
  • Swine / genetics*
  • Transplantation, Heterologous

Substances

  • Antibodies
  • Immunoglobulin G
  • Mixed Function Oxygenases
  • CMPacetylneuraminate monooxygenase
  • Galactosyltransferases
  • N-acetyllactosaminide alpha-1,3-galactosyltransferase