Kevin Cook at the Bloomington Stock Center was funded by the National Institutes of Health to generate chromosomal deletions. The project was able to push deletion coverage of the euchromatic genome to 98.4% and breakpoint subdivision of the genome into intervals containing a median of nine genes. The project is described in Cook et al., 2012 and Roote & Russell, 2012. Stocks carrying BSC deficiencies can be found here.

Deletions with BSC numbers greater than 99 were generated using the FRT-bearing transposable element insertions from Exelixis, Inc. (Thibault et al., 2004) by the methods of Parks et al., 2004. These deletions have molecularly mapped endpoints and share the isogenic background of the Exelixis deletions and insertions.

To build deletions in the same background see Generating deletions from Exelixis insertions.

Most deletions with lower BSC numbers were generated by the Hybrid Element Insertion (HEI) method described in Parks et al., 2004 and are not isogenic. These deletions were induced by P-element transposase in the presence of trans-heterozygous P-element insertions. The HEI model predicts that one deletion endpoint will correspond to the insertion site of one of the starting insertions and the other endpoint will map near the other insertion site. The precise endpoints have not been characterized molecularly. Df(3L)BSC1, Df(3L)BSC2 and Df(2L)BSC7 were generated by irradiation mutagenesis and are not isogenic. Their breakpoints have been characterized cytologically, but not molecularly.