Figure 4.
Augmin Is Required for Maintenance of Mitotic Spindle Integrity
(A and B) Stills from movies of spindle formation in embryos expressing Tubulin-GFP; Histone-RFP (A) or EB1-GFP (B) injected with interfering antibodies generated against the Augmin subunit, Dgt6. Astral MT and spindle formation are delayed, progressing to weak elongated spindles which arrest.
(C) Stills from movies of spindle formation in msd1ex51 embryos expressing Tubulin-GFP.
(D) Stills from movies of Msd1-GFP-expressing embryos. Msd1-GFP localizes to MTs in interphase (i) and metaphase (ii). Following injection of anti-Dgt6 antibodies, Msd1-GFP dissipates from all MTs close to the site of injection during interphase (iii) and mitosis (iv). Weak MT localization remains in areas distant (∼50 μm) from the site of injection (v).
(E and F) Stills from movies of spindle formation in embryos expressing Rod-GFP (E). Rod localizes to assembling kinetochores in prophase and streams poleward on MT-kinetochore attachment, gradually decreasing with time (30”–120”). In (F), upon injection of anti-Dgt6 antibodies, Rod-GFP streaming is delayed but occurs, signifying the presence of K-fibers. Localization of Rod-GFP to kinetochores and kMTs persists throughout the observation period.