Molecular characterization of two PD suppressor-containing cytological regions 21B7-21C2 and 50E4-50F6. A, Characterization of the PD-interacting cytological region 21B7-21C2. B, Characterization of the PD-interacting cytological region 50E4-50F6. The regions uncovered by the deficiencies used in the experiments are indicated (dashed line). The effect of each deficiency is indicated as suppression (+) or no suppression (-). The genes (arrows) are listed according to their genomic location. opa1EY09863 is an opal loss-of-function allele in which a P-element-containing sequence is inserted into the opa1 locus. Df(2R)β4GalNAcTA[20.1] and β4GalNAcTA4.1 were generated by imprecise excision . In the Df(2R)β4GalNAcTA[20.1] allele, both β4GalNAcTA and CG8531 are deleted, while 610 base-pair sequence in the β4GalNAcTA gene is deleted in the β4GalNAcTA4.1 allele.