Chapter 6 Gap junctions

Publisher Summary This chapter describes the importance of gap junctions in patterning and development using various animal model systems and the mammalian heart. The chapter discusses some specific developmental defects in the human that appear to result from gap junction gene perturbations. Gap junctions play a major role during development and patterning, and in controlling cell proliferation and growth, providing the pathway and regulating the direct cell-to-cell exchange of signals. Their importance starts with the oocyte, but their influence persists through all stages of development as they are responsible for maintaining homeostasis in the adult. Antibody probes used in immunohistochemical studies have proven valuable in studying gap junction distribution in developing organisms; the greater overview provided has given many advantages over the ultrastructural techniques employed previously. In combination with dye transfer and electrophysiological experiments, the evidence for gap junctional roles has mounted. While much of the evidence for this is correlative, the development of functional antibody probes that specifically block cell-cell communication has enabled several experimental systems to be probed directly.