Fig. 5. ALE1 is expressed in endosperm surrounding developing embryos. (A-E) Pattern of distribution of ALE1 mRNA. (A) Seed containing the globular stage embryo. Signals (brown coloration) were observed in the endosperm around suspensor cells and weak signals were also detected in the embryo and suspensor cells themselves. (B) A globular-heart transition stage embryo and endosperm before cellularization. (C) Seed containing a heart-shaped embryo and cellularized endosperm. Strong signals (dark blue coloration) were observed in some of the cellularized endosperm that surrounded the embryo. (D) An embryo and endosperm at the heart stage. Strong signals were detected in some of the endosperm cells around the embryo. (E) Embryo and endosperm at the walking-stick stage. Signals were detected in some of the endosperm cells at positions closest to the embryo. (F,G) Sense controls for A to E. Reddish brown or weak blue signals in the cell layer underneath the seed coat and in the seed coat cells (indicated by white asterisks) were not specific to ALE1 RNA because they were generated by both the antisense and the sense probe. (H) GUS activity in endosperm cells of a transgenic plant that harbored the ALE1 promoter-GUS fusion gene. Scale bars, 50 µm.
