Culture conditions for in vitro culture of bovine embryos have been the subject of many studies, both for understanding reproductive physiology and for application in the embryo transfer industry. A variety of embryo culture systems that include coculture with somatic cells, culture in conditioned media, and culture in defined media with or without serum/BSA are presently employed. Chemically defined media for bovine embryo culture are especially useful for analyzing the physical action of substances such as inorganic compounds, energy substrates, hormones, cytokines, and vitamins on the development of preimplantation embryos.
During mammalian development, a number of cytokines play a functional role in the process of cellular proliferation, differentiation, and morphogenesis in a spatial and temporal manner. In early preimplantation embryos, it has been noticed that cytokines produced by both the female genital tract and the embryo itself act on embryonic cells as paracrine/autocrine factors. In cows, a variety of cytokines including transforming growth factor (3, basic fibroblast growth factor, leukemia inhibitory factor, platelet-derived growth factor, insulin-like growth factor-I, granulocyte-macrophage colony-stimulating factor, and activin A have been reported to affect the development of preimplantation embryos. buy ventolin inhalers
In recent studies, addition of activin A to bovine and murine embryo culture media has increased the number of 1-cell embryos reaching the morula or blastocyst stage.