Df(3L)BSC371 was isolated as a FLP recombinase-induced recombination event involving PBac{WH}CG17150f03522 and P{XP}Blimp-1d06859. 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; PBac{WH}CG17150f03522/P{XP}Blimp-1d06859 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}BSC371 from the segment of PBac{WH}CG17150f03522 to the left of its FRT site and the segment of P{XP}Blimp-1d06859 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(3L)BSC371 predicted from the Release 5 genomic coordinates of the transposable element insertion sites are 64C1;64E1. Df(3L)BSC371 failed to complement Klp64Dk1 and CG4769KG05986.