Disruption of the fate of the C blastomere using pal-1(RNAi) knockdown results in delayed and minimal contact between the C and the ABar blastomeres before division of ABar causing the ABar spindle to be misaligned

(Left) Contact is minimal and is delayed between the C blastomere (membrane near contact outlined in blue) and the ABar blastomere (membrane near contact outlined in green). Focal depth (14 μm) of greatest contact is shown. (Right) In lieu of a polarizing signal from the C blastomere, the ABar blastomere (right line) adopts the default spindle orientation and divides parallel with the ABpr blastomere (left line). Focal depth is 7 μm. [Supplemental movie from Imaging in Developmental Biology: A Laboratory Manual, Cold Spring Harbor Laboratory Press.]