Fig. 3. PAR localization in double embryos. Double embryos were immunostained for the PAR protein listed above each panel. The subset of AB descendants visible are indicated by 1 or 2, according to origin, and names of some of the P1 descendants are indicated. Both germline blastomeres (P2) are indicated with asterisks in A. (C,D) Upper and lower focal planes of the same double embryo. Note the blastocoel visible at the center of the 1 and 2 cells in C. At the time of fixation, double embryos were equivalent to the following single embryo stages: (A) 4-cell plus 4-cell, (B) 8-cell plus 8-cell, (C,D) 7-cell plus 8-cell. Bar, 10 µm.