Validation of the fusion transcript BCAS4/BCAS3 found in MCF7 cells. (A) Three-hundred-thirty-nine copies of PET-0s were found to encode a putative BCAS4/BCAS3 fusion transcript. The top panels show the genomic regions for chr20q13 and chr17q23 and the lines below indicate the regions encoding BCAS4 and BCAS3 genes and their exon-intron structures. Portions of the first exon of BCAS4 and last exon of BCAS3 are expanded to show the PET mapping distributions along chromosome 20 between 48,845,002 and 48,845,295 (the 5′ end of BCAS4) and chromosome 17 between 56,824,953 and 56,824,980 (the 3′ end of BCAS3). (B) FISH analysis showed the amplification and colocalization of BCAS3 (green) and BCAS4 (red) genes. (C) Fusion transcript and inferred gene structures revealed by RT-PCR and sequencing analysis are shown. The exact breakpoint mapped by genomic PCR is displayed at the bottom.
