FlyBase curator comment: this entry is used to capture phenotypic information when the particular allele (or allele combination) used by the author could not be determined but the context of the experiment suggests that the phenotype being described is some kind of loss of function.
Mutant embryos lack cephalic furrows.
btdunspecified has phenotype, suppressible by Sp1btd.PS
Addition of Sp1btd.PS flies rescues the chordotonal organ phenotype seen in btdunspecified almost to wild-type, revealing at least four scolopidia per organ.