Abstract
The effect of the protein transport inhibitor brefeldin A (BFA) on compaction of early mouse embryos was investigated morphologically and immunocytochemically. After placing 4- and 8-cell mouse embryos in a medium with BFA for 3 or 6 h, the features of compaction were investigated. It was found that the effects of BFA on compaction were dependent upon the cell stage when this drug was applied. Compaction was delayed when embryos were placed in BFA during the mid or late 8-cell stage (3-6 and 6-9 h post division to the 8-cell stage). In embryos treated with BFA, Roh-ConA binding was weakened and detected at the cell contact regions. The distribution of microvilli seemed to be altered. It was concluded that protein transport for compaction was initiated at the early 8-cell stage just before the development of the compacted state.
