Fig. 6. Cytoplasmic flow, as indicated by traces of particle movement, during axial expansion (cycle 4 to cycle 8) may contribute to uneven distribution of CycB within an embryo. Both A and B are projections of three-minute time-lapse recordings every 10 seconds of a wild-type embryo at cycle 6. These bright-field transmission images were recorded on a two-photon optical workstation (Wokosin et al., 2003). There is little particle movement in interphase [A, see Baker et al. (Baker et al., 1993) for staging]. By contrast, dramatic particle movement can be observed between interphase and anaphase [B, see Baker et al. (Baker et al., 1993) for staging]. Note the inward flow in the middle region. (C) The direction of the flow in prophase and metaphase. Scale bar: 50 µm.