Reprograming of murine blastocoele formation.

The present study shows that there is communication between reaggregated asynchronous cleavage stage blastomeres that regulates blastocoele formation. Individual blastomeres from eight-cell murine embryos were transferred to empty zonae pellucidae, intact two-cell embryos, or enucleated two-cell embryos, and were examined over a period of 75 hours for development of cavitation. It was found that the isolated blastomeres cavitated concurrently with intact control eight-cell embryos, while intact control two-cell embryos cavitated 24 hours later. However, the embryos resulting from combining a two-cell embryo and a blastomere from an eight-cell embryo cavitated at a time in between the eight- and two-cell controls.