Figure 4.

(A) Crosses between wild-type strains or crosses of either klp2Δ with itself, pkl1Δ with itself or dhc1-d1 with itself result in low levels of spore death, except the latter cross at 20°C. Homozygous crosses of klp2Δ,dhc1-d1, of pkl1Δ,dhc1-d1, or of the triple deletion, on the other hand, result in catastrophic levels of spore death. (B) The percent spore death resulting from sporulation of wild-type azygotic diploids and of azygotic diploids that were homozygous klp2Δ,dhc1-d1 were indistinguishable. Other azygotic dipoids show more spore death, but the percentage is still reduced, relative to the zygotic crosses. (C) A typical early zygote, resulting from klp2Δ,dhc1-d1 × klp2Δ,dhc1-d1. The two unfused nuclei have a shape that is characteristic of a late zygotic nucleus in wild-type cells during the processes of “horsetailing” (Ding et al., 1998).