Figure 2.

Microscopic Analysis of the orc2 Zygotic Lethal Phenotype.

(A) to (D) Thin-sectioned seeds of orc2/+ plants stained with toluidine blue. Wild-type ([A] and [C]) and mutant ([B] and [D]) seeds from the same siliques. In (B), the arrow points to an enlarged endosperm nucleus. In (D), the arrows show aberrant cell divisions, and the inset shows an enlarged endosperm nucleus from the same seed.

(E) to (H) Wild-type (E) and mutant ([F] to [H]) seeds that were cleared, whole mounted, and viewed with Nomarski optics.

(F) Typical orc2 phenotype in a seed from the same silique as (E). Arrows point to enlarged endosperm nuclei.

(G) Normal embryo but abnormal endosperm (arrow).

(H) Rare almond-shaped embryo.

Arrows in (A), (C), and (E) point to normal endosperm nuclei. Bar = 10 μM.