Fig. 2. Marker gene expression in ANT::STM plants. (A-H) Light micrographs of GUS-stained, cleared seedlings. (A) CycB1;1::CDBGUS expression in wild type. Staining is restricted to the SAM region and young leaves (arrowhead), but is absent from the expanded first pair of rosette leaves (arrow). (B) CycB1;1::CDBGUS; ANT::STM-expressing seedling of the same age as the one in A. Staining is seen throughout the first pair of rosette leaves (arrow). (C) CycB1;1::CDBGUS; ANT::STM seedling with intermediate phenotype. Ectopic GUS staining is observed in the lateral outgrowths of the leaves (arrows). (D) ANT::STM; ANT::GUS-expressing seedling. The transgenes are strongly expressed in the vasculature of the cotyledons (c), leaf primordia (arrowhead) and in older leaves with stronger staining at the tips (arrow), as well as in their lateral outgrowths (not visible). (E) KNAT1::GUS expression in wild type. Staining is restricted to the SAM region and hypocotyl, yet is absent from leaves. (F) KNAT1::GUS; ANT::STM-expressing seedling. Ectopic GUS staining is seen in the vasculature of the cotyledons (c) and in strongly affected leaves (arrow). (G) KNAT2::GUS expression in wild type. Staining is restricted to the SAM region and is absent from cotyledons (c) and leaves (arrow). (H) KNAT2::GUS; ANT::STM-expressing seedling. Ectopic GUS staining is observed in the vasculature of the cotyledons (c) and in leaves (arrow). (I,J) In situ hybridization with a CLV3 antisense riboprobe. In both wild-type (I) and ANT::STM-expressing (J) seedlings, CLV3 mRNA is exclusively detected in the stem cells in the three outermost layers of the SAM. Scale bars are 1 mm in A-H, 100 µm in I,J.