Effects of delayed excision of oviducts/ovaries on mouse oocytes and embryos.

To achieve the best and reproducible results of experiments, effects of delayed excision of oviducts/ovaries on mouse ovarian/ovulated oocytes and embryos have been studied. Oviducts/ovaries were excised at different times after death of mice and effects of the postmortem interval on ovarian/ovulated oocytes and embryos were analyzed. When oviduct excision was delayed 10 min, many ovulated oocytes lysed or underwent in vitro spontaneous activation, and this postmortem effect aggravated with the extension of postmortem interval and oocyte aging.

Effects of species and cellular activity of oviductal epithelial cells on their dialogue with co-cultured mouse embryos.

An efficient co-culture system, especially with oviductal or uterine epithelial cells, is important not only for the production of high quality embryos, but also for the study of the molecular dialogue between embryos and their maternal environment. Although mouse embryos have been co-cultured successfully with oviductal epithelial cells (OECs) from several species, studies on the effects of species and functionality of OECs are few. Reports concerning the necessity of direct contact between the embryo and OECs and about the culture of mouse embryos in medium conditioned with heterologous OECs have been controversial.

Production of cloned goats by nuclear transfer of cumulus cells and long-term cultured fetal fibroblast cells into abattoir-derived oocytes.

Dairy goats are ideal for the transgenic production of therapeutic recombinant proteins. The use of recombinant somatic cell lines for nuclear transfer (NT) allows the introduction of genes by transfection, increases the efficiency of transgenic animal production to 100%, and overcomes the problem of founder mosaicism. Although viable animals have been cloned via NT from somatic cells of 11 species, the efficiency has been extremely low.

Effects of cell cycle status on the efficiency of liposome-mediated gene transfection in mouse fetal fibroblasts.

Methods for cell cycle synchronization of mouse fetal fibroblast cells (MFFCs) were first selected and optimized. When MFFCs were cooled at 5 C for different periods of time, the highest percentage of cells at the G0/G1 phase (75.4+/-2.

[Factors affecting liposome-mediated gene transfection of mouse somatic cells].

We studied the effects of the amount of liposome and plasmid, exposure time of cells to the liposome-plasmid complexes, number of cell passages and cell types on GFP gene transfection of mouse somatic cells. The maximal GFP transgene expression (30.7%) was achieved when mouse fetal fibroblast cells (MFFC) at 70%-90% confluence of passage 3 were exposed for 6 h to the complexes of 4 microg liposome (LipofectAMINE) and 0.

Parthenogenetic activation of mouse oocytes by strontium chloride: a search for the best conditions.

Strontium has been successfully used to induce activation of mouse oocytes in nuclear transfer and other experiments, but the optimum treatment conditions have not been studied systematically. When cumulus-free oocytes were treated with 10mM SrCl(2) for 0.5-5h, activation rates (88.

Effects of duration, concentration, and timing of ionomycin and 6-dimethylaminopurine (6-DMAP) treatment on activation of goat oocytes.

The protocol of ionomycin followed by 6-dimethylaminopurine (6-DMAP) is commonly used for activation of oocytes and reconstituted embryos. Since numerous abnormalities and impaired development were observed when oocytes were activated with 6-DMAP, this protocol needs optimization. Effects of concentration and treatment duration of both drugs on activation and development of goat oocytes were examined in this study.

Effects of post-treatment with 6-dimethylaminopurine (6-DMAP) on ethanol activation of mouse oocytes at different ages.

To study the effect of post-treatment with 6-Dimethylaminopurine (6-DMAP) on oocyte activation and development, mouse oocytes collected at different times post human chorion gonadotropin (hCG) injection were incubated in 6-DMAP-containing Chatot-Ziomek-Bavister (CZB) medium for different periods after ethanol exposure, and activation and development were observed. When oocytes were cultured in 6-DMAP without prior ethanol exposure, the highest activation rate was only 40%. Incubation in 6-DMAP for 6 h following ethanol exposure significantly (P < 0.

Changes in germinal vesicle (GV) chromatin configurations during growth and maturation of porcine oocytes.

Changes in germinal vesicle (GV) chromatin configurations during growth and maturation of porcine oocytes were studied using a new method that allows a clearer visualization of both nucleolus and chromatin after Hoechst staining. The GV chromatin of porcine oocytes was classified into five configurations, based on the degree of chromatin condensation, and on nucleolus and nuclear membrane disappearance. While the GV1 to 4 configurations were similar to those reported by previous studies, the GV0 configuration was distinct by the diffuse, filamentous pattern of chromatin in the whole nuclear area.

[The tempo of meiosis of goat oocytes].

The meiotic progression of goat oocytes from follicles of different diameters was investigated in this study. The results were summarized as follows: (1) The in vitro meiotic maturation capacity was different among oocytes from follicles of different diameters. And thus oocytes from < or = 0.