Fig. 9. Model for L and Ser function in cell survival during early eye development. L and Ser are required for cell survival during early eye development by preventing the ectopic induction of Wg- and JNK-signaling pathways in the ventral eye or in the entire eye disc prior to the establishment of the DV pattern. L and Ser can inhibit the JNK signaling pathway indirectly by repressing Wg signaling. It is also possible that L and Ser directly block JNK signaling. JNK-signaling activation can induce both caspase-dependent and -independent cell death. Thus, L and Ser promote cell survival by blocking both JNK-signaling-mediated and caspase-dependent cell death.