UASt regulatory sequences drive expression of a mutated form of caps (amino acid replacement Y507G).
tracheal dorsal trunk primordium, with Scer\GAL4twi.PG
Embryos that express capsY507.Scer\UAS under the control of Scer\GAL4twi.PG show tracheal defects; the dorsal trunk shows gaps and this phenotype is more severe at stage 14 than in later embryonic stages.