Acquisition and expression of a Bp-likeCPS gene by variant Bt isolates. (a) aCGH signals of variant Bt stains (BtCDC3015869 and BtE555) within the Bt EPS cluster region and Bp CPS cluster regions of the BPGA. Top: signal dips in the Bt EPS region (blue genes, BTH_I1324 to 1343) indicate absence of this region in both BtCDC3015869 and BtE555. Bottom: signal peaks in the Bp CPS region (red genes, BPSL2787 to BPSL2810, wcbT-manC) indicate gain of this region in both BtCDC3015869 and BtE555. All aCGH signals represent comparisons against BtE264. Breakpoints in both BtCDC3015869 and BtE555 are demarcated by solid black lines. (b) PCR detection of Bp CPS genes in variant Bt strains. Six Bp CPS genes (marked by black bars in (a) were assayed. Lanes: 1, Bp K96243 (yellow); 2, BtE555 (green); 3, BtCDC3015869 (cyan); 4, BtE264 (pink); 5, water control (grey). Also shown are 100-bp and 500-bp ladders. (c) Western blot analysis of BpK96243 (positive control, lane 1), and three Bt strains (BtE555, BtCDC3015869 and BtE264, lanes 2 to 4) using a monoclonal antibody directed to Bp CPS (anti-Bp CPS) demonstrates expression of cross-reacting Bp-likeCPS in BtE555 and BtCDC3015869 at around 200 kDa, but not for the negative control (BtE264, lane 4). (d) Immunofluorescence analysis confirms Bp-likeCPS expression in both BtCDC3015869 and BtE555, but not BtE264. Bacteria were co-stained with anti-Bp CPS antibodies (red) and DAPI (blue) to identify nuclei.