Mutation maps outside the 3' end of the transcription unit.
Hemizygous abd-Aiab2-Uab1 adults show partial transformation of A1 into A2 and of A2 into A1 such that A1 and A2 look very much alike. Transheterozygous combinations with abd-Aiab2-S3 display no detectable effect on A2.
Reversion studies show that abd-Aiab2-Uab1 causes abnormal expression of abd-A domain functions in A1.
Partial loss of abd-A product. Ectopic expression of the protein during germ band elongation (FBrf0049558).