Isolation and characterization of Df(3L)BSC393 Stacey Christensen, Kimberley Cook and Kevin Cook Bloomington Stock Center Indiana University Df(3L)BSC393 was isolated as a FLP recombinase-induced recombination event involving P{XP}vsgd03524 and PBac{RB}CG6718e00344. 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}vsgd03524/PBac{RB}CG6718e00344 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.RB3}BSC393 from the segment of P{XP}vsgd03524 to the left of its FRT site and the segment of PBac{RB}CG6718e00344 to the right of its FRT site. Its presence was verified using the PCR methods and primers described in Parks et al. with the substitution of the primer 5'-CCAATGCGTTTATTTCAGGTCACG-3' for the RB3' plus or RB3' minus primer in the Hybrid PCR protocol in the Supplementary Methods. The cytological breakpoints of Df(3L)BSC393 predicted from the Release 5 genomic coordinates of the transposable element insertion sites are 67C5;67C11. Df(3L)BSC393 failed to complement Gap1B2. Df(3L)FDD-0048912 is a synonym for Df(3L)BSC393.