Bovine blastocysts obtained from reconstructed cytoplast and karyoplasts using a simple portable CO2 incubator.

To enable both the multiplication of elite livestock and the engineering of transgenic animals for various agricultural and biochemical purposes, scientists around the world are intensively studying efficient ways of improving developmental competency of bovine embryos reconstructed by somatic cell nuclear transfer. Because it is widely accepted that culture conditions along with many other factors contribute to the developmental competency of reconstructed embryos, this preliminary study was designed to test whether or not bovine reconstructed embryos could develop in vitro using a simple portable CO(2) incubator. CO(2) and O(2) gas tensions and air pressure can be varied using this system.

Growth factors and growth hormone enhance in vitro embryo production and post-thaw survival of vitrified bovine blastocysts.

The objective of this study was to assess the influence of specific growth factors and growth hormone (GH) in the culture medium on in vitro embryo production and post-thaw survival of vitrified blastocysts. In total, 1673 bovine oocytes were used for evaluating the nuclear status of the oocytes after in vitro maturation (n=560) or for in vitro fertilization (IVF, n=1113) and distributed in five treatment groups: (1). medium only control; (2).

Comparison of the effects of using standard and simple portable CO2 incubators on the in vitro developmental competence of bovine embryos reconstituted by somatic cell nuclear transfer.

In an attempt to determine the cultural factors that would improve cloning efficiency, we compared the effects of two incubation systems-a simple portable system and a standard CO2 incubator-on the production of bovine embryos by electrofusion of quiescent fetal fibroblast nuclei to enucleated oocytes matured in vitro. While the temperature (38.5 degrees C) and CO2 concentration (5%) were similar in both systems, the portable incubator operated in a vacuum of 300 mmHg and at an O2 level of 8-10%, which is lower than the standard.

Improvement of the culture conditions for in vitro production of cattle embryos in a portable CO2 incubator.

The effects of different concentrations of growth hormone (GH) on in vitro maturation (IVM), fertilization (IVF) and culture (IVC) of bovine oocyte/embryos in CR1aa or CR2aa media using a simple CO2 incubator were investigated. The IVM/IVF/IVC of oocytes were carried out in the presence of 0, 50, 100 and 200 ng/ml GH in the medium. The proportion of metaphase II oocytes was significantly higher (p < 0.

The effect of prefreezing the diluent portion of the straw in a step-wise vitrification process using ethylene glycol and polyvinylpyrrolidone to preserve bovine blastocysts.

A total of 678 bovine blastocysts, which had been produced by in vitro maturation, fertilization, and culture, were placed into plastic straws and were vitrified in various solutions of ethylene glycol (EG) + polyvinylpyrrolidone (PVP). Part of the straw was loaded with TCM199 medium + 0.3 M trehalose as a diluent; the diluent portions of the straw were prefrozen to either -30 or -196 degrees C.