Sheep Cloned by Nuclear Transfer
From a Cultured Cell Line by Campbell KH. McWhir J. Ritchie WA. Wilmut I.
Nature 1996 Mar 7;380(6569):24-5, Comment in:
Nature 1996 Apr 4;380(6573):383
(The beginning - "Dolly" is cloned.)
Abstract: Nuclear transfer has been used in mammals
as both a valuable tool in embryological studies and as a method for the
multiplication of 'elite' embryos. Offspring have only been reported when
early embryos, or embryo-derived cells during primary culture, were used
as nuclear donors. Here we provide the first report, to our knowledge,
of live mammalian offspring following nuclear transfer from an established
cell line. Lambs were born after cells derived from sheep embryos, which
had been cultured for 6 to 13 passages, were induced to quiesce by serum
starvation before transfer of their nuclei into enucleated oocytes.
Induction of quiescence in the donor cells may modify the donor chromatin
structure to help nuclear reprogramming and allow development. This approach
will provide the same powerful opportunities for analysis and modification
of gene function in livestock species that are available in the mouse through
the use of embryonic stem cells.