Following steps are associated with generation of transgenic animal by SCNT procedure:
1. Mature oocyte is arrested at metaphase-II phase and enucleated.
2. Somatic donor cells are cultured in vitro and somatic cell derived nucleus is transferred to enucleated oocytes.
3. The resulting nuclear transfered oocytes are activated and embryogenesis is activated.
4. The embryo is generally allowed to develop in vitro till blastocyst stage.
5. The blastcyst embryo is then implanted into the uterus of surrogate female where the further development of the embryo takes place.

Fig6-3.3.5: Somatic cell nuclear transfer

6-3.3.5 Sperm Mediated Gene Transfer (SMGT):

Sperm mediated gene transfer was first reported in 1989 which is based on ability of sperm cells to internalize exogenous DNA and transfer it to the egg cells. This method utilizes a “natural vector” (sperms) to deliver foreign DNA. The exogenous DNA binds to sperm’s head at sub-acrosomal region and DNA molecules are taken up by sperm cells. After DNA-sperm interaction and internalization, the exogenous DNA gets integrated to the genome.