Active demethylation of cytosine residues in the sperm genome before forming a functional
zygotic nucleus is thought to be an important function of the oocyte cytoplasm for …

In mammals, active demethylation of cytosine methylation in the sperm genome prior to
forming a functional zygotic nucleus is thought to be a function of the oocyte cytoplasm …

Active demethylation of the paternal genome but not of the maternal genome occurs in
fertilized mouse, rat, pig, and bovine zygotes. To study whether this early demethylation …

During differentiation, somatic nuclei acquire highly specialized DNA and chromatin
modifications, which are thought to result in cellular memory of the differentiated state [1] …

Background Cloning of cattle by somatic cell nuclear transfer (SCNT) is associated with a
high incidence of pregnancy failure characterized by abnormal placental and foetal …

Cloning by nuclear transfer (NT) has been riddled with difficulties: most clones die before
birth and survivors frequently display growth abnormalities. The cross‐species similarity in …

Full-term development has now been achieved in several mammalian species by transfer of
somatic nuclei into enucleated oocytes [1, 2]. Although a high proportion of such …

Despite the fact that cloned animals derived from somatic cells have been successfully
generated in a variety of mammalian species, there are still many unsolved problems with …

DNA demethylation and remethylation are crucial for reprogramming of the differentiated
parental/somatic genome in the recipient ooplasm upon somatic cell nuclear transfer. Here …

Epigenetic reprogramming is a prerequisite process during mammalian development that is
aberrant in cloned embryos. However, mechanisms that evolve abnormal epigenetic …