Complex pattern of GHRLOS variant exon expression. GHRLOS transcripts A to M were demonstrated by RT-PCR, while the 5' end (exon I) and 3' end (exon 4) were determined by RACE, inverse PCR and by examining publically available Affymetrix exon array data and expressed sequence tag (EST) data. Exons are represented as boxes, introns as horizontal lines and sizes (bp) are indicated below each exon. The size of exon 4a is listed as 1377–1388 and corresponds to a transcript which is polyadenylated 20–30 bp from the same polyadenylation signal (data not shown). Exon 4b harbours the same polyadenlation site, but is 5' truncated (250 bp). GhrelinOS variants A to M have been deposited to GenBank: A-F, stomach [GenBank:EU789534, EU789535, EU789536, EU789537, EU789538, and EU789539]; G-H, prostate [GenBank:EU789540, and EU789541]; I, foetal brain [GenBank:EU789542]; J-M, heart [GenBank:EU789543, EU789544, EU789545, and EU789546].