Fig. 4. Effect of microinjection of anti-PSTAIRE antibody on germination. Injection of the anti-PSTAIRE antibody at 1 hour AF inhibited germination and cell division in 18 out of 20 zygotes, as determined 36 hours (black in F) to 48 hours later (zygote in A). By contrast, injections at 8 hours AF allowed 19 out of 25 zygotes to germinate in response to unidirectional light and to divide as determined at 36 hours (white in F) or 48 hours AF (zygote in B). Twenty out of 25 zygotes, injected at 1 hour AF with the same concentration of control ascite fluid germinated and divided, as determined at 30 hours (C), 36 hours (white in F) and 48 hours AF (D,E) though the division planes were sometimes misaligned (D) compared with controls injected with injection buffer only (E). Arrowheads point to the rhizoids. Scale bar: 40 µm in A,C,D,E; 50 µm in B.