New advances in somatic cell nuclear transfer: Application in transgenesis

The ability to produce live offspring by nuclear transfer from cultured som atic cells provides a route for the precise genetic manipulation of large a nimal species. Such modifications include the addition, or "knock-in", and the removal or inactivation, "knock-out", of genes or their control sequenc es. This paper will review some of the factors which affect the development of embryos produced by nuclear transfer, the advantages of using cultured cells as donors of genetic material and methods that have been developed to enrich gene targeting frequency. Commercial applications of this technolog y in biomedicine and agriculture will also be addressed. (C) 1999 by Elsevi er Science Inc.