The Bloomington Deficiency Kit provides maximal coverage of the genome with the minimal number of deletions having molecularly mapped breakpoints. Regions not covered by molecularly defined deletions exist as gaps in coverage or they are deleted by cytologically defined deficiencies. Haplolethal and haplosterile loci are flanked as closely as possible with deletions as well as being covered by deletions when possible.
The molecularly defined deletions were generated primarily by the Bloomington Deletion Project, the DrosDel Project and Exelixis, Inc. from FRT-bearing transposable element insertions. Breakpoints have usually been mapped to single-base resolution. Other deletions have typically been characterized by polytene cytology and complementation tests with molecularly mapped mutations. Cook et al. (2012) provides detailed information about the construction of the Bloomington Deficiency Kit. Also see Roote and Russell (2012).