Fig. 1. Loss of L function causes selective induction of cell death in the ventral eye. (A,A') Wild-type eye imaginal disc showing a few randomly distributed TUNEL-positive nuclei of dying cells. (B,B') L-mutant eye disc (L²/+), showing TUNEL-positive ventral eye cells nuclei (arrow). (B,B') Semicircular dashed line marks the lost boundary of the ventral eye field. (C,C') LOF clones of L show TUNEL-positive cells nuclei in the ventral eye (arrow). The cells lacking L gene function in the dorsal half of the eye are not affected (arrowheads). Straight dashed lines in A-C indicate the approximate midline - the border between the dorsal (D) and ventral (V) eye.