Figure 4.

Centrioles Are Essential for Early Embryonic Development

(A and B) WT (A) and DSas-4 mutant (B) embryos from a 1–4 hr collection stained for tubulin (red), centrosomes (Cnn [green]) and DNA (blue). The WT embryo is ∼1 hr old and contains many well-organized spindles. The mutant embryo, although at least 1 hr old, is arrested early in development with only 6–7 disorganized anastral spindles. Scale bars represent 100 μm.

(C) High magnification view of spindles in a DSas-4 mutant embryo. All the spindles appear to be anastral, although one possesses a Cnn dot at one pole. This embryo contained a second Cnn dot not shown here. Scale bars represent 10 μm.

(D) A DSas-4 mutant embryo containing two closely associated Cnn dots that each nucleate a large MT aster. Scale bars represent 10 μm.