Fig. 6. Expression of the shoot apical meristem marker genes in the obe1 obe2 double mutant. (A,B) CLV3::GUS expression in 4-day-old wild-type (A) and obe1 obe2 (B) seedlings. (C,D) WUS::GUS expression in 4-day-old wild-type (C) and obe1 obe2 (D) seedlings. (E-H) CLV3::GUS expression in wild-type (E,G) and obe1 obe2 (F,H) embryos. Embryos shown are at the heart (E,F) and the torpedo (G,H) stages. (I-P) In situ hybridization with WUS (I-L) and STM (M-P) antisense probes hybridized to embryos from self-fertilized OBE1/obe1 obe2/obe2 plant. Longitudinal sections through embryos at different stages of embryogenesis are shown. (I,J) Heart stage embryos. (K,L,O,P) Bent-cotyledon stage embryos. (M,N) Torpedo stage embryos. (J,L,N,P) obe1 obe2 embryos. (I,K,M,O) Wild-type siblings. In obe1 obe2 embryos, weak WUS expression was detected (J), but WUS expression was undetectable at the bent-cotyledon stage (L). STM expression in obe1 obe2 (N,P) was similar to that in wild-type sibling (M,O). Scale bars: 100 µm in A-D; 25 µm in E-P.