NUCLEAR TRANSPLANTATION IN MAMMALS - REMODELING OF TRANSPLANTED NUCLEI UNDER THE INFLUENCE OF MATURATION PROMOTING FACTOR

Whilst the role of Maturation or M-phase Promoting Factor (MPF) as a u niversal M-phase regulator is well documented, much less attention has been paid to its role in nuclear transplantation experiments and espe cially to its influence upon remodelling of transplanted nuclei. There is currently wide acceptance that successful nuclear transplantation using differentiated nuclei is possible only in a cytoplasmic environm ent that is capable of inducing rapid nuclear dedifferentiation to a p ronuclear-like form. In this review our purpose is firstly, to outline the conditions under which such remodelling can be induced, and secon dly, to extend the debate to include a consideration of whether comple te nuclear remodelling is an absolute necessity for clonal development .