Fig. 4

Putative cell–cell interactions observed in the gastrulating polyclad flatworm M. crozieri. a–i A descendant of cell 4d¹ (red arrow) is traced and can be seen approaching and later departing from fourth quartet macromeres 4A-D before epiboly is completed. Time represents hours (h) of time-lapse imaging with an OpenSPIM. Scale bars are50 µm