Isolation and characterization of Df(3L)BSC669 Stacey Christensen, Kim Cook and Kevin Cook Bloomington Stock Center Indiana University Df(3L)BSC669 was isolated as a FLP recombinase-induced recombination event involving PBac{WH}CG3280f01875 and P{XP}vsgd03524. The deletion was isolated as a chromosome carrying two copies of the miniwhite marker in progeny of w1118; P{hs-hid}3, Dr1/TM6C, Sb1 cu1 females crossed to P{hsFLP}1, y1 w1118; PBac{WH}CG3280f01875/P{XP}vsgd03524 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{XP3.WH3}BSC669 from the segment of PBac{WH}CG3280f01875 to the left of its FRT site and the segment of P{XP}vsgd03524 to the right of its FRT site. The cytological breakpoints of Df(3L)BSC669 predicted from the Release 5 genomic coordinates of the transposable element insertions sites are 67C2;67C5. Df(3L)BSC669 failed to complement fry02240 and alphaTub67C1.