Polytene chromosomes normal.
lethal | pharate adult stage P15 (with Pfas4)
lethal | prepupal stage P2 (with Pfas4)
lethal | pupal stage P5 (with Pfas4)
Auxotroph for purine. Eye colour: yellow-orange. Homozygotes have a yellow-orange eye colour. Reduced wing size, deranged posterior wing margins and extra wing veins. Bristles are thinner and sometimes reduced in size.
Exhibit purine autotrophy and defective FGARAT (EC 6.33.5.3) enzyme.