An FRT cassette containing a transcription stop signal and a y+t* marker separates a αTub84B promoter from a mutated hpo coding region that carries mutations in 4 of the 5 autophosphorylation sites of the linker region (T356A, T374A, T387A, T421A). The 5th autophosphorylation site T431 has not been mutated (this residue is also part of a mats protein binding site in the wild-type protein).
In animals with muscle-specific hpo4A-431T.αTub84B.FRT.Tag:FLAG clones, the indirect flight muscles show atrophy and muscle fiber compaction after 32h APF.
Flies expressing hpo4A-431T.αTub84B.FRT.T:Zzzz\FLAG from a tubulin promoter in the eye through Scer\FLP1ey.PU-mediated excision of an intervening FRT cassette from the transgene leads to pupal lethality.