Conversion of cell fate is not only an essential biological question, but also has great clinical values. In early 1950s, cellular reprogramming was first achieved using the technique of somatic cell nuclear transfer (SCNT), which transferred the nuclear of somatic cells into an enucleated oocyte, thus converted the mature somatic cells into pluripotent state. Using this technique, Xenopus laev...

The ability of frozen-thawed fetal skin was examined to generate viable cell lines for nuclear transfer. Fetal skin frozen at -35 degrees C or -80 degrees C in the presence of 5% DMSO were used as tissue explants to generate somatic cells. The resultant confluent cells were then used as donors for nuclear transfer (NT). Of the bovine NT embryos reconstructed from the somatic cells, 78% to 81% s...

In mouse somatic cell nuclear transfer (SCNT), polyvinylpyrrolidone (PVP) is typically included in the nuclear donor injection medium. However, the cytotoxicity of PVP, which is injected into the cytoplasm of oocytes, has recently become a cause of concern. In the present study, we determined whether bovine serum albumin deionized with an ion-exchange resin treatment (d-BSA) was applicable to t...

With the increasing difficulties associated with meeting the required needs for organs used in transplantation, alternative approaches need to be considered. These include the use of stem cells as potential sources of specialized cells, the ability to transdifferentiate cell types in culture, and the development of complete organs that can be used in humans. All of the above goals will require ...

Continuation of mammalian species requires the formation and development of the sexually dimorphic germ cells. Cultured embryonic stem cells are generally considered pluripotent rather than totipotent because of the failure to detect germline cells under differentiating conditions. Here we show that mouse embryonic stem cells in culture can develop into oogonia that enter meiosis, recruit adjac...

Assisted reproductive techniques in the horse have been only recently become available compared to other domestic species, in particular ruminants. The scarce availability of abattoir ovaries and the lack of interest from horse breeders and breed associations, and the anatomical and physiological differences have been the main reasons for this delay. Progressively though, the technology of oocy...

The transplantation of somatic cell nuclei to enucleated eggs has shown that genes can be reprogrammed to an embryonic pattern of expression, thereby indicating a reversal of their epigenetic state. However, in Xenopus nuclear transfer experiments using both endoderm and neuroectoderm donor cells, we have observed substantial overexpression of donor cell type-specific genes, both spatially and ...

Interspecies somatic cell nuclear transfer (iSCNT) is a useful method to preserve endangered species and to study the reprogramming event of a nuclear donor cell by the oocyte. Although several studies of iSCNT using murine cells and bovine oocytes have been reported, the development of murine-bovine iSCNT embryos beyond the 8-cell stage has not been successful. In this paper, we examined the d...

This experiment was studied to examine the in vitro developmental potential of enucleateddomestic cat oocytes reconstructed with skin fibroblasts from female domestic and leopard cats. The cumulus oocyte complex of domestic cat were cultured in IVM medium under 38.5°C, 5%CO2, 5%O2,90%N2 for 24 hours. The matured oocytes were enucleated and individual donor cell was inserted into...