Evaluation of gene targeting by homologous recombination in ovine somatic cells

Sarah H. Williams, Virender Sahota, Timea Palmai-Pallag, Scott J. Tebbutt, Jean Walker, Ann Harris*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Mouse models for some human genetic diseases are limited in their applications since they do not accurately reproduce the phenotype of the human disease. It has been suggested that larger animals, for example sheep, might produce more useful models, as some aspects of sheep physiology and anatomy are more similar to those of humans. The development of methods to clone animals from somatic cells provides a potential novel route to generate such large animal models following gene targeting. Here, we assess targeting of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in ovine somatic cells using homologous recombination (HR) of targeting constructs with extensive (>11 kb) homology. Electroporation of these constructs into ovine fetal and post-natal fibroblasts generated G418-resistant clones, but none analyzed had undergone HR, suggesting that at least for this locus, it is an extremely inefficient process. Karyotyping of targeted ovine fetal fibroblasts showed them to be less chromosomally stable than post-natal fibroblasts, and, moreover, extended culture periods caused them to senesce, adversely affecting their viability for use as nuclear transfer donor cells. These data stress the importance of donor cell choice in somatic cell cloning and suggest that culture time be kept to a minimum prior to nuclear transfer in order to maximize cell viability.

Original languageEnglish (US)
Pages (from-to)115-125
Number of pages11
JournalMolecular reproduction and development
Issue number2
StatePublished - Oct 1 2003


  • Animal model
  • Nuclear transfer
  • Senescence

ASJC Scopus subject areas

  • Genetics
  • Developmental Biology
  • Cell Biology


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