Figure 1.

Transcriptional Requirements in Embryo and Endosperm.

(A) Whole-mount clearing of a wild-type seed at the one-cell embryo stage. Emb, embryo; End, endosperm.

(B) Whole-mount clearing of developmental abnormalities induced by downregulating POLII in pNG-POLII RNAi lines at the one-cell (top) or 4/8-cell (center) embryo stages with arrested central cell development and seed at 2 DAP with a slow-growing endosperm (bottom).

(C) Distribution of embryo and endosperm developmental stages in RNAi lines with arrested central cell development and wild-type seeds 2 to 4 DAP.

(D) Whole-mount seeds counterstained with DAPI (marking chromatin) after immunostaining of the active form of RNA POLII (H5 antibody) or RNA POLII independently of its transcriptional engagement (4H8 antibody), as indicated. Projections of consecutive sections are shown. The seeds are at the zygotic stage, and the endosperm has undergone two cleavages. The box corresponds to the close-up. The arrow indicates the zygote nucleus; endosperm nuclei are indicated by stars.

Bars = 10 μm.

[See online article for color version of this figure.]