Lethality acts in the second larval instar. Phenotype similar to blot⁰¹⁶⁵⁸. Females with germ line clones show strongly reduced fertility. Affected embryos first show a defect as a delay in the formation of pole cells and a frequent reduction in number of pole cells. As nuclei reach the periphery, few actin filaments are present and no organisation into F-actin caps or mitotic pseudo-cleavage furrows can be detected. The spacing between nuclei becomes irregular. Many nuclei have abnormal shape, fuse and drop into the interior of the embryo. Cellularisation completely fails. The embryo remains a polynucleate mass, which gradually deteriorates.