Deletion of most of the 3' UTR and fusion of Ecol\lacZ gene to aid detection in in situ hybridizations.
As for bcdΔ21 i.e. a deletion of bases 4056-4726 (coordinates of FBrf0047926) in bcd 3' UTR, with addition of a 1.3kb Ecol\lacZ gene fragment to aid detection in in situ hybridizations.
Transcripts are not localized in the oocyte.