Fig. 6. L is involved in the repression of wg during second larval instar. (A-C) Abolishing wg function in different time windows using a temperature-sensitive wg^IL114 allele (details in Materials and methods) shows that second instar of larval development (L2) is crucial for L-Wg interaction. (B) When wg function was abolished during first or third instar, there was no significant rescue of the L-mutant phenotype. (C) When wg function was abolished during second instar, loss-of-ventral-eye phenotype of L²/+ mutants was significantly rescued to near that of wild-type eye. (D) In second instar wild-type larval eye disc, wg-lacZ is expressed strongly on the dorsal margin. (E) In the L²/+-mutant background, a strong induction of wg-lacZ reporter expression is seen all along the ventral polar margin. Dashed lines in D,E mark the boundary between the dorsal- and the ventral-half of the eye. (D,E) Inset shows wg-lacZ expression (red) in a separate channel in second instar eye imaginal discs. (F) In the second instar eye disc, LOF clones of L cause ectopic induction of Wg and Drice in the ventral eye (arrowhead). Separate channels are shown in inset.