A 3850 base pair fragment from the flanking non-coding or intronic region of grn is fused upstream of a Drosophila core synthetic promoter (DSCP) that is followed by sequence encoding a GAL4 driver.
Optogenetic activation (using Crei\ChR2UAS.cSa with 470 nm (blue) light) of Scer\GAL4GMR26H06 cells in larvae results in a significant increase in backup behaviors, compared to controls.