Yoko Kato* and Yukio Tsunoda
Laboratory of Animal Reproduction, College of Agriculture, Kinki University, Nara, Japan
ABSTRACT Cloning efficiency has not been dramatically improved after the first success of somatic cell nuclear transfer (SCNT) in sheep in 1997. The reasons for the low efficiency of SCNT embryos must be attributed to the insufficient reprogramming of the donor nucleus in ooplasm. It has been clarified that the methylation and acetylation status are disordered in SCNT embryos and the gene expression pattern is different and widely varied in SCNT embryos, compared with fertilized embryos. In this paper, we focused on the role of the donor nuclei in cloning efficiency, and discuss whether ooplasm can reprogram any nucleus.
Keywords:*Corresponding author e-mail: yoko@nara.kindai.ac.jp