Construct: btd::Mmmm\Sp1 fusion protein consists of the 13 amino acids of the btd N terminus fused to the full length Mmmm\Sp1 coding sequence so the initiator Met residue encodes amino acid 14 of the fusion protein.
Partially rescues the btdXG phenotype; the mandibular segment is partially rescued, but the intercalary and antennal segments of the embryo are not rescued.