Fig. 3. (A,B) Stereotyped pattern of invagination sites. (A,B) Confocal micrographs of the opisthosoma of two different embryos stained with phalloidin-rhodamine. The invagination sites occupy the same positions in each hemisegment. The arrows point to two invagination sites that are located at the lateral anterior edge of each hemisegment. The arrowheads point to high phalloidin staining in the PNS. o1 to o5 opisthosomal segments 1 to 5. Scale bars: 200 µm.