Homozygotes die at the late pupal stage. sagunspecified/+ embryos derived from a cross of females containing homozygous sagunspecified germline clones to sagunspecified/+ males are viable with no phenotype. Homozygous sagunspecified embryos derived from the same cross die during embryogenesis and have a number of defects; the head skeleton is collapsed (in 50% of embryos), abdominal segment 8 is partially deleted and the size of the anal pads is reduced and associated structures are abnormal. Late embryos lack gut constrictions. Tracheal branches are fragmented with incomplete connections. The width of the denticle bands and the distance between the Keilin's organs appears grossly normal. The central nervous system appears grossly normal. Severe defects are seen in the peripheral nervous system; most if not all chordotonal organs are missing, and neurons of the external sensory organs are abnormal in number and arrangement. Homozygous clones in the wing cause a deletion of vein L4.