Different transcripts of the GLB1 gene. (a) Scheme of the GLB1 gene. Different possible transcripts are shown. The primers used to amplify these transcripts are indicated by horizontal arrows. Black circles are natural stop codons whereas red circles indicate PTCs. (b) &(c) RT-PCR on cDNA from cycloheximide-treated (CHX) or not treated (NT) HeLa cells and human fibroblasts. The transcripts corresponding to each band are outlined on the right. (b) PCR using C1F/EBPR as primers. (c) PCR using EBPF/C3R as primers. * indicates bands for possible transcripts including only exon 3 or only exon 4.