Our previous study showed that recombinant human activin A stimulates development of bovine zygotes to the blastocyst stage when they are cultured in a chemically defined medium (modified synthetic oviduct fluid medium; mSOF) under a gas atmosphere of 5% CO2 in air. However, mSOF is optimized under an atmosphere of 5% CO2:5% O2:90% N2 rather than 5% CO2 in air. In our previous study, the percentages of zygotes that developed to the blastocyst stage were relatively low (6-19%) even when activin A was added to mSOF.
Follistatin is a glycosylated polypeptide, originally isolated from porcine follicular fluid, that inhibits FSH secretion. This protein has a high affinity for activin and is known as an activin-binding protein. Follistatin is expressed in diverse tissues, including gonads, pituitary, uterus, heart, lung, thymus, etc., and neutralizes activin bioactivity in various systems, such as in the stimulation of FSH secretion in cultured pituitary cells and in the differentiation of granulosa cells. However, it has not been determined whether follistatin neutralizes the development-enhancing effects of activin A in bovine embryos. buy cipro
The objectives of this study were to confirm the development-enhancing effects of activin A in bovine embryos produced by in vitro maturation (IVM) and in vitro fertilization (IVF) using a chemically defined medium (mSOF) under a gas atmosphere of 5% Co2:5% O2:90% N2, and to determine the effects of follistatin or a combination of ac-tivin A and follistatin on embryo development. Furthermore, the developmental stages of embryos affected by these cytokines were examined.