Effect of mitotic inducers and retinoic acid blocker on expression of pluripotent genes in ES cells derived from early stage in vitro-produced embryos in buffalo

So far, it has been difficult to generate embryonic stem (ES) cell from early stage preimplantation embryos of buffalo. These ES cells will be more helpful for efficient embryo cloning and generation of body cells as they are more primitive than inner cell mass (ICM)-derived ES cells. The present study was conducted to find the effect of lipopolysaccharide (LPS), melatonin (N-acetyl-5-methoxytryptamine, a pineal gland product), and citral (3,7-dimethyl-2,6-octadienal and a retinoic acid synthesis blocker) on establishment of primary ES cell colonies, the comparative size of the ES cell colonies, and expression of pluripotent genes during extended period of culture in buffalo. Zona-free eight-cell stage in vitro fertilization (IVF) embryos were cultured in ES cell medium supplemented with none (media I as control), LPS (media II), citral melatonin (media III), or melatonin (media IV). The multiplication of blastomere leading to ES cell colony formation and expression of pluripotent genes were assessed up to day 20 of culture. The primary colony formation, the comparative size of the ES cell colonies, and expression of pluripotent genes in these colonies were better in the medium supplemented with melatonin in all days of culture. Within melatonin supplementation, the colony size was comparatively larger on day 8 and day 12 of culture. Further, with this supplementation, the Oct-4 and Nanog expression was comparatively higher on all days of culture. The results indicated that supplementation of melatonin helped in the formation of better primary ES cell colony as well as in the maintenance of pluripotency. The results also indicated that primary colonies developed on day 8 to day 12 of culture may be better for passaging them for establishment of ES cell line from early stage preimplantation IVF embryos of in buffalo.