Isolation and characterization of Df(2R)BSC597 Stacey Christensen, Kim Cook and Kevin Cook Bloomington Stock Center Indiana University Df(2R)BSC597 was isolated as a FLP recombinase-induced recombination event involving PBac{WH}f00834 and P{XP}d02202. The deletion was isolated as a chromosome lacking miniwhite markers in progeny of P{hsFLP}1, y1 w1118; PBac{WH}f00834/P{XP}d02202 males crossed to w1118; P{hs-hid}2, wgSp-1/SM6a females. 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}BSC597 from the segment of PBac{WH}f00834 to the left of its FRT site and the segment of P{XP}d02202 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(2R)BSC597 predicted from the Release 5 genomic coordinates of the transposable element insertions sites are 58A2;58F1. Df(2R)BSC597 failed to complement dve01738.