Background: The most important factor affecting the efficiency of somatic cell nuclear transfer (SCNT) is the initial quality of the oocyte. Since the abattoir-derived oocytes are heterogeneous in quality, selection of cohort fully grown/competent oocytes is necessary for proper development of SCNT embryos. Materials and Methods: Glucose-6-phosphate dehydrogenase (G6PDH) is actively expressed i...

The developmental competence of in vitro cultured (IVC) embryos is markedly lower than that of their in vivo counterparts, suggesting the need for optimization of IVC protocols. Embryo culture medium is routinely replaced three days after initial culture in bovine, however, whether this protocol is superior to continuous nonrenewal culture method under current conditions remains unclear. Using ...

In somatic cell nuclear transfer (SCNT), donor cell reprogramming is considered as a biologically important and vulnerable event. Various donor cell pre-treatments with Xenopus egg extracts can promote reprogramming. Here we investigated if the reprogramming effect of one treatment with Xenopus egg extract on donor cells was maintained for several cell passages. The extract treatment resulted i...

Many of the developmental anomalies observed in cloned animals are related to fetal and placental overgrowth, a phenomenon known as the “large offspring syndrome” (LOS) in ruminants. It has been hypothesized that the epigenetic control of imprinted genes, i.e. genes that are expressed in a parental-specific manner, is at the root of LOS. Our recent research has focused on understanding the epig...

Foot-and-mouth disease, one of the most significant diseases of dairy herds, has substantial effects on farm economics, and currently, disease control measures are limited. In this study, we constructed a vector with a human interferon-α (hIFN-α) (without secretory signal sequence) gene cassette containing the immediate early promoter of human cytomegalovirus. Stably transfected bovine fetal fi...

To improve the culture system of bovine somatic cell nuclear transfer (SCNT) embryos, we studied the effects of activin A on developmental competence of bovine SCNT embryos during the early development stage based on the traditional culture method, and analyzed the expression level of the genes related to blastocyst hatching (Na/K-ATPase, Glut-1) and related to activin A signalling pathway (Act...

Although mammalian cloning by somatic cell nuclear transfer (SCNT) has been established in various species, the low developmental efficiency has hampered its practical applications. Treatment of SCNT-derived embryos with histone deacetylase (HDAC) inhibitors can improve their development, but the underlying mechanism is still unclear. To address this question, we analysed gene expression profil...

BACKGROUND Somatic cell nuclear transfer (SCNT) involves the transfer of somatic cell nuclei into enucleated oocytes. Because human in vivo matured oocytes are scarcely available, we investigated whether in vitro matured (IVM) germinal vesicle (GV) oocytes could also support preimplantation development of human cloned embryos. METHODS Three groups were used for SCNT: in vitro matured GV oocyt...

Studies using animal models demonstrated the importance of autocrine/paracrine factors secreted by preimplantation embryos and reproductive tracts for embryonic development and implantation. Although in vitro fertilization-embryo transfer (IVF-ET) is an established procedure, there is no evidence that present culture conditions are optimal for human early embryonic development. In this study, k...

Imprinting disorders induced by somatic cell nuclear transfer (SCNT) usually lead to the abnormalities of cloned animals and low cloning efficiency. Histone deacetylase inhibitors have been shown to improve gene expression, genomic methylation reprogramming and the development of cloned embryos, however, the imprinting statuses in these treated embryos and during their subsequent development re...