Fig. 3. WUS and CLV3 expression in jba-1D shoot apical meristems. (A) GUS expression from a pWUS::GUS reporter construct in a wild-type seedling SAM, after 1 hour incubation in X-Gluc substrate. (B) No pWUS::GUS activity is detected in a wild-type seedling SAM after 20 minute incubation in X-Gluc substrate. (C) pWUS::GUS activity is readily detected in a jba-1D seedling SAM after 20 minute incubation in X-Gluc substrate. The WUS expression domain also expands laterally in the jba-1D SAM. (D) In some jba-1D seedlings, two independent foci of WUS expression are observed (arrows). (E) GUS expression from a pCLV3::GUS reporter construct in a wild-type seedling SAM. (F) The CLV3 expression domain expands laterally in a jba-1D seedling SAM, coordinate with the expansion of the WUS expression domain. All seedlings are 11 days old. (G) CLV3 and WUS mRNA transcription levels in Col and jba-1D inflorescences and floral meristems as determined by real-time qRT-PCR. Scale bars: 40 µm.