Figure 1.—

PCR analysis of D1 P-insertion alleles. The left–right block arrow represents the P{EP}D1^EP473 element inserted within the 5′-UTR of the D1 genomic locus. The relative locations of the PCR primers used to analyze the insertion and its excision derivatives and PCR product sizes are shown. The distance between the D1 proximal and D1 distal primers was too large for PCR amplification with standard Taq polymerase when the entire P{EP} element was present, but yielded a 794-bp product in its absence. The P{EPgy2}D1^EY05004 insertion is similarly located in the 5′-UTR but in the opposite orientation. PCR analyses of this element typically utilized the Pry2 primer (adjacent to the Pry4 primer; not shown) instead of the Pry4 primer.