A set of isogenic deficiency stocks created by FLP-induced recombination between FRT-carrying transgenic insertions; molecularly defined deletion endpoints correspond to initial location of the progenitor insertions. Initial set of 519 isogenic deletions provides 56% genome coverage.
The current Exelixis collection at the Bloomington Stock Center differs from the original described in FBrf0175003 : a significant number were shown not to carry a deletion and have been removed from the collection; a number of stocks have been lost; a number of additional deletions are included that were generated after publication.
Deletion-generation strategy made use of extensive collections of isogenic FRT-carrying transgenic insertion lines (FBrf0175002); used insertions of P{XP}, PBac{RB} and PBac{WH}. Recombination between FRT elements in two insertions in the appropriate relative orientation results in deletion of the genomic region between the insertions and production of a hybrid element that contains one FRT element at the recombination point (FBrf0091061). Animals were generated that carried a heat-shock-inducible FLP recombinase gene and 2 FRT-carrying transgenic insertions in trans; these were subjected to a heat-shock regimen during larval stages. After eclosion, females were collected and crossed to appropriate males for detection of miniwhite[-] or miniwhite[+] deficiency chromosomes; isolate lines were established using isogenized balancer stocks. Candidate deletions were confirmed by PCR of multiple isolate lines for each deletion. In general, it was sufficient to test 5 putative lines for each miniwhite[-] deletion and 50 putative lines for each miniwhite[+] deletion.
The deletion collection was not verified genetically at Exelixis; most have been assessed since then at the Bloomington Stock Center. 77 stocks were determined not to carry a deletion; most of these were likely to have been false positives recovered from the deletion screens. An additional 23 stocks are no longer available because they have been lost or have broken down or because they were identical to alternate stocks.
