Df(3R)BSC320 was isolated as a FLP recombinase-induced recombination event involving P{XP}casd10725 and PBac{WH}f00649. The deletion was isolated as a chromosome lacking miniwhite markers in progeny of w1118; Dr1/TM6C, Sb1 females crossed to P{hsFLP}1, y1 w1118; P{XP}casd10725/PBac{WH}f00649 males. These males were heat shocked as larvae as described in Parks et al., Nature Genetics 36: 288-292, 2004 (FBrf0175003). This cross and crosses in preceding and succeeding generations maintained the original genetic background of the Exelixis insertion stocks (Thibault et al., Nature Genetics 36: 283-287, 2004; FBrf0175002). The recombination event generated the genetic element P+PBac{XP5.WH5}BSC320 from the segment of P{XP}casd10725 to the left of its FRT site and the segment of PBac{WH}f00649 to the right of its FRT site. Its presence was verified using the PCR methods and primers described in Parks et al. The cytological breakpoints of Df(3R)BSC320 predicted from the Release 5 genomic coordinates of the transposable element insertion sites are 83C1;83D4. Df(3R)BSC320 failed to complement Rm62EY06795 and Df(3R)Exel7284. Df(3R)FDD-0116468 is a synonym for Df(3R)BSC320.