3.

Origin of human DLC-1 and DLC-2 transcriptional variants. (A). Diagram of the genomic region at the 5′ end of DLC1, with exons represented by boxes. The five exons comprising the novel 5′sequence of the KIAA1723 transcript are labelled A–E, and the alternative first exon of the AK025544 transcript is denoted as 1*. The three transcripts share exons 2–14, and the distances between the putative transcription start sites (marked with arrows) and exon 2 are indicated. (B). Diagram of the 5’end of the DLC-2 gene, showing the first exons of the DLC-2α (1α), DLC-2β (1β) and DLC-2γ (1γ) isoforms. Exons 2–14 are common to all three transcripts, and the distances between exon 2 and the putative transcription start sites are indicated. The genomic DNA distances in A and B were obtained from the human genome sequence compilation (NCBI Build 36) and are not drawn to scale. The structures of the human DLC-3 gene and its transcripts were described in Ref 22.