Role of gap junctions in the development of the preimplantation mouse embryo.

We have taken several approaches to study the role of gap junctional communication during preimplantation mouse development. Firstly, the normal expression pattern of gap junctions has been characterized using immunostaining in conjunction with laser scanning confocal microscopy. Changes in junctional distribution have been correlated with developmental events. We have gone on to study development and junctional organization in mice which naturally exhibit reduced cell to cell communication (DDK syndrome), and in normal mice in which gap junction permeability has been artificially manipulated. Furthermore, anti-peptide antibodies have been tested for their ability to block gap junction communication and for the effects of such a block on subsequent development. Collectively, the results demonstrate that gap junctional communication plays an important role in the maintenance of compaction and the differentiation of an organized epithelium within an embryo, features which are vital for preimplantation development to progress successfully.