Fig. 8. Expression of STM, ANT and CUC2 in wild-type and laterne (pid-15 enp) embryos. (A,B,D,G,I,K,M,O,Q,R,T,U,W) Wild-type, (C,E,F,H,L,N,P,S,V,X) laterne, (A-H) STM expression, (I-P) ANT expression and (Q-X) CUC2 expression. (A-C,F,I-N,S,U,V,X) Arranged in series (top to bottom). (A,B) Cross-section series (top view) of globular stage (A) and heart stage embryo (B) with stripe-like domain of STM expression (arrowheads). (C) Cross section heart stage (top view). (D,E) Lateral views of wild-type (D) and laterne (E) heart stage embryos. (F) Tangential to median sections of young laterne torpedo stage (black arrowheads indicate patches of higher intensity). (G) Wild-type torpedo with STM expression defining the SAM. (H) Comparable picture of laterne torpedo, with patch-like pattern of STM signal. (I,K) Longitudinal series showing the ring-like ANT expression pattern in globular stage (I) and stained cotyledon primordia in heart stage (K). The black arrowheads in I and K indicate the central region lacking ANT. (L) Longitudinal series of laterne heart stage with ANT expression (arrowhead indicates emerging apical cavity without signal; arrows indicate emerging expression in vascular precursors). (M) Wild-type cross-section series with signal concentration in vascular precursors. (N) Cross-section series shows extension of ANT domain in apical pole of laterne, avoiding the centre (arrowhead). (O) Longitudinal section of wild-type torpedo (slightly out of centre; arrows as in L). Inset shows cotyledon cross-section. (P) Longitudinal section of laterne torpedo (arrowhead: apical cavity lacks ANT signal). Inset displays tangential cut to stress ring-shaped ANT expression. (Q,R) Globular (Q) and early heart stage (R) each with CUC2 expression. (S) laterne heart stage longitudinal series with distributed patches of expression (arrowheads). (T) Wild-type at late heart stage. (U) Wild-type cross-section series indicating the early stripe-like pattern. (V) A laterne cross-section (arrowheads: expression peaks); signal is also present in the centre. (W) Longitudinal section in torpedo embryo with lateral (ring-shaped) signals, avoiding the central SAM region (arrows). The inset is at a higher magnification. (X) Series of torpedo stage laterne with distributed expression (arrowhead). co, cotyledon; hy, hypocotyl; SAM, shoot apical meristem; vSAM, variable SAM. Scale bars: 20 µm.