Isolation and characterization of Df(3R)BSC636 Stacey Christensen, Kim Cook and Kevin Cook Bloomington Stock Center Indiana University Df(3R)BSC636 was isolated as a FLP recombinase-induced recombination event involving P{XP}GluClalphad09990 and PBac{WH}Hs6stf04953. The deletion was isolated as a chromosome lacking miniwhite markers in progeny of w1118; P{hs-hid}3, Dr1/TM6C, Sb1 cu1 females crossed to P{hsFLP}1, y1 w1118; P{XP}GluClalphad09990/PBac{WH}Hs6stf04953 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}BSC636 from the segment of P{XP}GluClalphad09990 to the left of its FRT site and the segment of PBac{WH}Hs6stf04953 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(3R)BSC636 predicted from the Release 5 genomic coordinates of the transposable element insertions sites are 92B1;92C1. Df(3R)BSC636 failed to complement bnl00857.