300bp fragment from -1.6 to -1.3kb of the sna promoter and the proximal 250bp of the sna promoter drives lacZ expression.
A 300bp fragment from -1.6to -1.3kb of the sna promoter plus the proximal 250bp of the sna promoter drivesEcollacZ gene expression in the ventral-most 10-12 cells of the embryo.