Abstract:
Somatic cell nuclear transfer (SCNT) has been an area of interest in the field of stem cell
research and regenerative medicine for the past 20 years. The main biological goal of SCNT is to
reverse the di erentiated state of a somatic cell, for the purpose of creating blastocysts from which
embryonic stem cells (ESCs) can be derived for therapeutic cloning, or for the purpose of reproductive
cloning. However, the consensus is that the low e ciency in creating normal viable o spring in
animals by SCNT (1–5%) and the high number of abnormalities seen in these cloned animals is due to
epigenetic reprogramming failure. In this review we provide an overview of the current literature
on SCNT, focusing on protocol development, which includes early SCNT protocol deficiencies and
optimizations along with donor cell type and cell cycle synchrony; epigenetic reprogramming in
SCNT; current protocol optimizations such as nuclear reprogramming strategies that can be applied to
improve epigenetic reprogramming by SCNT; applications of SCNT; the ethical and legal implications
of SCNT in humans; and specific lessons learned for establishing an optimized SCNT protocol using
a mouse model.
