ABSTRACT
The possibility of reprogramming the donor cell nucleus by the recipient oocyte makes current developments in nuclear transfer (NT) techniques useful for improvement of the methods for preimplantation genetic diagnosis (PGD). For example, it has become possible to convert interphase nuclei of single blastomeres and the second polar body (PB2) into metaphase for performing PGD by full karyotyping (Figure 3.1; see description below). This is an essential improvement, because the current fluorescence in situ hybridization (FISH) technique allows chromosomes to be enumerated on interphase cell nuclei, though with the number of chromosomes studied being limited to the number of chromosome-specific probes available. Even with the applicaiton of the methods for re-hybridization of interphase nuclei for the second and the third time, such karyotyping cannot be practical.
