Transgenic bovine nuclear transfer embryos from adult somatic cell lines

This study was performed to examine whether adult fibroblast cells can be manipulated genetically and whether clonal lines derived from those cells can support embryonic development. A primary adult cell line was established from the ear of an aged cow. Adult cells with a plasmid containing the enhancer green fluorescence protein (EGFP) gene, and non-transfected cells were used for cloning. Green fluorescence expression was observed in 35/49 (71.4%) adult clones. The developmental rates of embryos were significantly lower for cell lines expressing EGFP (11.4%) than for non-transfected cells (20.1%, P < 0.05). However, there was no decrease in nuclear transfer (NT) developmental rates (21.5%) when donor nuclei from EGFP transfected cell lines not expressing EGFP but retaining neomycin-resistance gene expression were used as donor nuclei. The NT embryos from transfected and non-transfected cell lines had similar morphology and cell numbers. The results indicated that adult cells can complete clonal propagation including transfection and selection and can be used to produce transgenic NT embryos.