Expression of Tc-lab in wildtype and Tc-kni RNAi embryos. Tc-lab expression appears prematurely in Tc-kni RNAi embryos (panels G, H, I; compare to equivalent stage wildtype embryos in panels A, B, C respectively). In Tc-kni RNAi embryos Tc-lab expression is always present but somewhat disturbed, including lack of median enlargement (H, I, L, compared to wildtype embryos in panels D, F) or lateral reduction (I, J, K, compare to wildtype embryos in panels D, E). See text for further details. The red background staining in each panel is weak FastRed signal for Tc-wg.