Fig. 4. GCM inhibits lz induction and maintenance but not LZ activity. (A-E) Side views of lz expression in stage 11 embryos. (A) Wild type. lz expression is repressed by GCM when gcm expression is driven in the whole mesoderm (B), the hemocytes (C) or the prospective crystal cells (D), but not when it is overexpressed in the plasmatocytes (E). (F-J) Side views of lz-lacZ expression in stage 11 embryos. lz-lacZ transcription is repressed upon overexpression of GCM in the mesoderm (G). Pan-mesodermal expression of SRP (H) or LZ (I) induces restricted activation of lz-lacZ, whereas co-expression of LZ and SRP (J) induces synergistic activation throughout the mesoderm. (K-N) Side views of DoxA3 expression in stage 16 embryos. Crystal cell formation is repressed by heat-shock induced transient expression of GCM around stage 10 (L), 11 (M) or 12 (N). No repression was observed in the absence of heat-shock treatment (K). (O-R) Side views of DoxA3 expression in stage 11 embryos. srp-gal4-driven expression of GCM represses DoxA3 expression (P). srp-gal4-driven expression of LZ activates DoxA3 expression (Q) and relieves GCM-induced repression upon DoxA3 (R).