Fig. 5. scraps (anillin) is required for the formation of microfilament rings during cellularization. (A-D) Sagittal sections (A,C) and projections of confocal sections of the cellularization front (B,D) of a scraps^RS/scraps^PQ mutant embryo shortly before (A,B) and after (C,D) the cellularization front has passed the nuclear bases. Embryos were stained with antibody to myosin. (A) The furrow canals of scraps mutant embryos during early cellularization are only slightly abnormal. (B) Microfilament rings are not present in scraps mutant embryos during early cellularization and the basal lumens are less rounded than in wild-type embryos. Myosin is found in aggregates scattered along the cellularization front (compare with Fig. 2C). (C) The furrow canals of scraps mutant embryos during late cellularization are collapsed and lack a flask-like morphology. (D) Microfilament rings are not present in scraps mutant embryos during late cellularization; the basal lumens are angular and are less rounded than those during early cellularization in scraps mutant embryos (compare with B). Myosin is found in aggregates scattered along the cellularization front (compare with Fig. 2G). Scale bar: 10 µm.