Fig. 6

Early embryogenesis of C. elegans. a pronuclei meet posteriorly; b central rotation of pronuclei; c central cleavage spindle; d posterior movement of posterior aster; e formation of two nuclei, initiation of cytokinesis; f 2-cell stage; g spindle orientation: transverse in AB and longitudinal in P1; h 4-cell stage; i polarity reversal with generation of anterior P3 and posterior C. For further details, see text. Arrows, centriolar regions; arrowheads, cleavage furrow; i for better visualization of polarity reversal in the germline AB cells had been removed through a laser-induced hole in the eggshell. Scale bar, 10 µm; orientation, anterior, left