Fig. 3.

Optic lobe enhancer contains sequences required for multiple expression patterns. Comparison of the D. santomea full intron reporter construct (A and C) with a construct in which the optic lobe enhancer has been deleted (B and D). Deletion of the optic lobe enhancer causes expression in the larval CNS to be strongly reduced (B, bracket, compared to bracket in A), whereas optic lobe expression is completely extinguished (B, arrow) compared with the complete intron construct (A, arrow). In the eye disc, expression is greatly reduced in the retinal field (bracket in C and D) and frons (arrow in C and D) by the deletion (D) relative to the activity of the complete intron (C).