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Fig. 4 Preferential segregation of Par-3 and internalized Dld to the posterior daughter following horizontal RGP division.Time-lapse sequence of images showing the dynamics of internalized Dld and Par-3-GFP in mitotic RGPs. DNA is marked by H2B-RFP (pseudo-colored in blue). Time = 2 min denotes telophase when asymmetry indices are calculated. (A) Both internalized Dld and Par-3-GFP are asymmetrically segregated to the posterior daughter shortly after division. (B) Both internalized Dld and Par-3-GFP appear symmetrically distributed shortly after division. (C) Both internalized Dld and Par-3-GFP appear asymmetrically segregated into the anterior daughter shortly after division. For (A) to (C), all images shown are the maximum MIP of five confocal z-stacks (1-μm z-step). The time interval between each volume of z-stacks is 30 s, and the total acquisition time is 30 min. (D) Quantification. Left: The asymmetry indices of Par-3-GFP (x axis) and internalized Dld (y axis) in 54 horizontally dividing RGPs. The dotted lines indicate the threshold of |0.2| for calling asymmetry. Right: Pie charts show the percentage of RGPs with different patterns of Par-3-GFP (top), and Par-3-GFP and internalized Dld (bottom) in 54 horizontally dividing RGPs. Most of the RGPs (64.8%) asymmetrically segregate Par-3 to the posterior daughter. Likewise, most of the RGPs (59.2%) asymmetrically segregate both Par-3 and Dld to the posterior daughter. Other minor classes of RGPs displaying different patterns of segregation might reflect real biological heterogeneity or noise due to mosaic nature of Dld labeling. The 54 RGPs are from 15 embryos in eight repeat experiments.