I would like to provide estimates for the genomic positions of the Df(3R)7B-90 breakpoints based on a combination of information communicated to the Bloomington Drosophila Stock Center by Barry Honda when he donate a Df(3R)7B-90 stock and information I obtained from crosses.
Honda said Df(3R)7B-90 failed to complement at least one spok mutation, but complemented at least one Pzl mutation. Consequently, the proximal breakpoint lies in the  3R:3263582..3354486  (R6) interval, where the left extent corresponds to the right end of Pzl and the right extent corresponds to the right end of spok.
I mapped the distal breakpoint with a series of crosses to deletions and mutations, and narrowed the breakpoint to the hkb-to-tub interval. Df(3R)7B-90 failed to complement hkbA321R1, but complemented tub2. Consequently, the distal breakpoint lies in the  3R:4345015..4387742  (R6) interval, where the left extent corresponds to the left end of hkb and the right extent corresponds to the left end of tub. Df(3R)7B-90 also failed to complement Skp2ex9.
Kevin
Kevin R. Cook, Ph.D.
Bloomington Drosophila Stock Center
Department of Biology
Indiana University