Figure 4.

Prom1 is concentrated at the midbody of NE cells. Mouse embryonic forebrain was subjected to preembedding immunogold labeling for prom1 (10 nm gold) followed by EM analysis of ultrathin serial plastic sections. Apical midbodies of NE cells at E8.5 (A–E), E10.5 (H–J), and E12.5 (F and G) are shown. (B and C) The central portion of the midbody with long, thin stalks depicted in B is shown at higher magnification of a consecutive section in C. (D and E) Consecutive sections showing the central portion of another midbody with long, thin stalks. (G–I) Midbodies with short stalks. (J) Particle at the apical surface of a neuroephithelial cell. Black arrowheads indicate prom1-labeled plasma membrane buds and protrusions, gray arrowheads indicate detached particles, solid arrows indicate midbody plasma membrane facing the lumenal side, and open arrows indicate midbody plasma membrane derived from cleavage furrow. Bars: (A and C–J) 100 nm; (B) 1 μm.