3.8kb deletion removing promoter proximal sna cis-regulatory sequences (containing two peaks of twi-protein binding).
snaΔProx partially rescues sna18/sna1
At 25[o]C, snaΔProx rescues 82% of sna1/sna18 animals to viability. At 18[o]C, 94% are rescued and at 29[o]C 36% are rescued.