Deletion of the Rpb4 coding region in P{CaSpeR4-Dtl+Ada2a+Rpb4+}.
Homozygous Df(3R)d189 mutants that also carry Ada2aDtl-Ada2a die during the first instar larval stage (L1).
Df(3R)d189 homozygous animals that carry both Ada2aDtl-Ada2a and Rpb4Scer\UAS.cPa transgenes develop like wild-type if a ubiquitous driver such as Scer\GAL4da.G32 ensures Scer\GAL4 production.
Ada2aDtl-Ada2a fails to rescue Df(3R)d189
Ada2aDtl-Ada2a fails to rescue the lethality of Df(3R)d189 homozygous animals.