Comparison of two sequence contigs from 22q reveals several intrachromosomal duplications distal to the BAM22 gene. The sequenced genomic clones are labeled by their EMBL/GenBank accession numbers above the bars. Contig B is located 2–2.5 Mb to the telomere as compared with the other contig (www.sanger.ac.uk/HGP/Chr22) (Collins et al. 1995). (A) Position and transcriptional orientation of eight genes located in the 287 kb contig formed by seven completely sequenced genomic clones. The gene abbreviations are as follows: (EWS) Ewing’s sarcoma gene (Delattre et al. 1992); (GAR22) a gene homologous to the mouse Gas2 gene (Zucman-Rossi et al. 1996); (RRP22) a member of the Ras family of genes (Zucman-Rossi et al. 1996); (BAM22) a beta-prime adaptin gene (Peyrard et al. 1994); (ADTB1) GDB symbol; (NEFH) neurofilament heavy chain polypeptide gene (Lees et al. 1988); (pK1.3) a gene of unknown function (Xie et al. 1993); (NIPSNAP1) gene (Seroussi et al. 1998); (RFPL1) Ret Finger Protein-Like 1 gene; (RFPLϑ1) Ret Finger Protein-Like pseudogene 1; (BAM22ϑ1) BAM22 pseudogene 1.BAM22ϑ1 is a regional duplication of a 8.5-kb genomic segment from BAM22 that contains identical copies of exons 2 and 3. RFPL1 gene is transcribed in both directions and the antisense transcript is denoted as RFPL1S. The arrows delineate the transcriptional orientation of genes. For the pseudogenes, the direction of arrows denote pseudogene orientations as if these were transcribed. (B) Delineation of the positions and transcriptional orientations of the genes located in the 316-kb contig telomeric to the human Na+/glucose cotransporter 1 gene (SGLT1, SLC5A1) (Turk et al. 1993). The second pseudogene of BAM22 (BAM22ϑ2) contains copies of exons 6 and 3 and the orientation of these exons is indicated above the bars. This pseudogene contains also 25.8 kb of sequence similar toBAM22ϑ1. Contig B contains also RFPL2,RFPL3, and RFPLϑ2, which is composed of two exons arranged in opposite orientations, which are indicated by two separate arrows. The transcription of RFPL3 has been detected only as the antisense transcript, denoted as RFPL3S. The exons forming the putative sense and the antisense transcript are numbered and presented above (sense) and below (antisense) the genomic contig.
