Isolation and characterization of Df(3L)BSC451 Stacey Christensen, Kim Cook and Kevin Cook Bloomington Stock Center Indiana University Df(3L)BSC451 was isolated as a FLP recombinase-induced recombination event involving P{XP}RpLP0d09567 and PBac{WH}CG14454f00525. 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}RpLP0d09567/PBac{WH}CG14454f00525 males. The 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}BSC451 from the segment of P{XP}RpLP0d09567 to the left of its FRT site and the segment of PBac{WH}CG14454f00525 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)BSC451 predicted from the Release 5 genomic coordinates of the transposable element insertions sites are 79B2;79F5. Df(3L)BSC451 failed to complement Hem03335, Aats-ile00827 and Ten-m05309.