P{A92} insertion close to the 5' end of the first intron of bab1. This results in aberrant splicing, with the 5' splice site of bab1 intron 1 and the 3' splice site of the l(3)87Df gene fragment which is present in the P{A92} insertion being spliced together. This produces a truncated 2.6kb transcript.
Homozygous females have an intermediate mutant ovary phenotype; the females are semi-sterile to sterile and ovaries have an irregular shape and are substantially smaller than normal. The ovaries contains a reduced number of ovarioles that are abnormally oriented. Homozygotes have wild-type legs. Homozygous females show ectopic dark pigmentation in the A6 and A7 tergites.
Mutant females lay only a small number of eggs, many of which develop normally. Mutant ovaries are disorganized and smaller than wild type. The wild type pattern of parallel anterior-posterior oriented ovarioles is not apparent in the mutant ovary. A few chains of egg chambers are apparent, with abnormally small terminal filaments that have the form of a cluster rather than a stack. These terminal filaments are attached to abnormally shaped germaria from which egg chambers develop that are not well aligned in the anterior-posterior axis.
Semi-sterile in females.
Formation of terminal filaments is disrupted: severely disorganised adult ovaries.
The P{A92}bab1P insertion does not affect the transcription of bab2.