Fig. 1.

Diapause natural variants map to Dp110. Wild-type W (filled circles) or C (open squares) flies were crossed to two deletions, which remove Dp110{yw;P[ry+,gH],Dp110^A/TM3,Ser,y⁺ (A) and yw;P[ry⁺,gH], Dp110^B/TM3,Ser,y⁺ (C)} and to two rescue lines each bearing a deletion plus a genomic Dp110 rescue fragment [yw;P{w⁺,g(Dp110⁹⁸)},Dp110^A/TM3,Ser,y⁺ (B) and yw;P{g(Dp110¹⁰¹)};Dp110^B/TM6B,Tb,Sb (D)]. From each of the four crosses, two populations of flies were recovered: one in which C or W was heterozygous with the deletion (or deletion plus rescue fragment) and one in which C or W was heterozygous with the balancer chromosome. The interaction plots show the mean proportion of flies in diapause (±SEM) for the progeny of each cross. There were significant statistical interactions between the proportions in diapause for deletion and the balancer [Dp110^A: F_(1,24) = 4.53, P < 0.04; Dp110^B: F_(1,24) = 30.47, P < 0.0001]. The lack of parallel lines found for the crosses to the deletion strains Dp110^A and Dp110^B indicate statistical interaction, demonstrating positive quantitative complementation (13). The interactions disappeared when the Dp110 genomic rescue fragments were present, indicating restoration of the phenotype with the genomic fragments [P{g(Dp110⁹⁸)} F_(1,17) = 0.03, P = 0.86; P{g(Dp110¹⁰¹)} F_(1,15) = 0.00, P = 0.95].