Gap junctional communication compartments in the Drosophila wing disk.

We have examined the gap junctional communication properties of cells in the wing imaginal disk of Drosophila, using intracellular injection of the fluorescent dye tracer Lucifer Yellow. The cell-to-cell passage of Lucifer Yellow is restricted at a boundary line that divides the wing disk into halves. We refer to each half as a "communication compartment" because there is a high level of gap junctional exchange within a compartment and much lower exchange between compartments. Comparison of the positions of the compartments with developmental fate maps suggests that cells in one communication compartment give rise to cuticular structures in the anterior half of the adult dorsal mesothorax, and cells in the other compartment contribute to posterior structures. This communication-restriction line appears to be coincident with the line between the anterior and posterior developmental compartments observed in studies of cell lineage. We propose that gap junctional communication restrictions may play a general role in generating or maintaining developmental compartments.