FlyBase curator comment: this entry is used to capture phenotypic information when the particular allele (or allele combination) used by the author could not be determined but the context of the experiment suggests that the phenotype being described is some kind of loss of function.
Septate junction development during stages 15 and 16 is similar to wild type in mutant embryos. However, at stage 17, only rudimentary septate junctions are apparent in the trachea and in the epidermis of mutant embryos, with only short regions of ladder-like septae being present. The cell membranes of neighbouring cells detach in the putative region of septate junctions and form bubble-like structures between the tracheal and epidermal cells. Adherens junction formation is normal in the mutant embryos.