Figure 2.

Defective early embryonic development of mutant eggs. Eggs laid by mud⁴ homozygote mothers stained for DNA (A and B, green; C, gray) and α-tubulin (A and B, red) are shown. (A and B) Embryos from mated mothers that have been aged for 2–4 hr contain numerous nuclei of varying size, many of which are associated with apparently anastral spindles and thus appear to be in the process of asynchronous division. When in moderate numbers, these nuclei are irregularly clustered near the center (A), but, when in larger numbers, the nuclei are distributed more broadly (B). Many of these nuclei are much larger and more intense than normal and do not appear to be associated with microtubules (arrowheads). (C) Unfertilized mutant eggs do not arrest normally after meiosis, but undergo DNA replication in the same manner as fertilized eggs. Bar, 50 μm.