Fig. 3. Perinuclear MT re-organisation in zygotes having localised cortical MTs. Four representative zygotes are shown (A-C), (D-F), (G-I), (J-L). (A,D,G,J) Nuclear region (projection of 5-6 sections) and (B,E,H) cortical region (projection of all sections) of 10-hour-old zygotes. In all zygotes cortical MTs are located at the hemisphere where germination will occur. (C,F,I) Transmitted images of germinated zygotes at 28 hours AF. (A) Perinuclear MTs are homogeneously nucleated from the nuclear envelope and thicker MTs extend toward the cortex of the future rhizoid. Two non-separated centrosomes are detected (arrow). (D) Centrosomes (arrows), almost aligned with the growth axis start to nucleate MTs. (G) MT nucleation occurs from centrosomes that are aligned with the growth axis. (J) MTs radiating in opposite directions from both centrosomes (aligned with the growth axis) towards the cortex. (K) Nuclear area of the same zygote 25 hours AF. Only MTs connected to the rhizoid site remain and the nucleus is pulled toward that site in the germinated zygote. (L) Projection of all sections of the same zygote. The bright patches in H and L correspond to unincorprated tubulin aggregate on the zygote surface at the site of injection. Bar, 15 µm.