FISH mapping of BACs on mitotic and polytene chromosomes. (A–C) BAC fluorescent hybridization signals (red, yellow) on mitotic chromosomes stained with DAPI (blue) are shown in pseudocolored images. Arrows indicate numbered divisions in the cytogenetic map of the pericentric and centric heterochromatin of mitotic chromosomes. Scale bar (A) indicates 3 µm. (A) BACR18B19 represents the previously unmapped Release 5 scaffold AABU01001089 and maps to division h26 on the X chromosome. (B) CH221-23H11 (red) represents the proximal end of the Release 5 arm X sequence, and CH223-33C13 (yellow) represents the distal end of the Release 5 XHet scaffold CP000208. Their signals overlap in h26p-h27; “p” indicates a proximal location within cytogenetic division h26. (C) CH223-01L14 represents the previously unmapped Release 5 scaffolds AABU01002700, AABU01002715, and AABU01001895 and produces a strong signal in h11-h14 on the Y chromosome. The long arm (YL) and short arm (YS) of the Y chromosome are indicated. (D–G) BAC and gene fluorescent hybridization signals (red, green) on polytene chromosomes of the wm4, SuUR Su(var)3-906 strain stained with DAPI (blue). Scale bar (D) indicates 3 µm. (D) BACR11F21 (red) and BACR30J23 (green) represent opposite ends of the Release 5 scaffold CP000188 and map to the proximal part of region 41A in the pericentric heterochromatin of chromosome arm 2R. BACR30J23 localizes distal to BACR11F21, orienting the scaffold. (E) BACR06D11 (red) represents the previously unmapped Release 5 scaffold CP000194 and localizes in the 20BC region of the X chromosome, proximal to DIP1 (green) in 20A. (F) BACR18B19 (green) represents the previously unmapped Release 5 scaffold AABU01001089 and also localizes in the 20BC region, distal to CG14621 (red) in 20C. (G) BACR06D11 and BACR18B19 signals overlap, but the strongest BACR06D11 signal is distal to the strongest BACR18B19 signal, suggesting their relative order. Sequence finishing shows that these BACs overlap each other by 40 kb.
