Genomic architecture of the Otop1 locus in vertebrates. (a) Mouse genomic region encompassing Otop1. The relative positions and transcriptional orientation of the indicated genes are drawn to scale, with the genomic structure of Otop1 provided in greater detail. The identical organization of genes within the depicted genomic region is also found in orangutan, macaque, galago, rat, guinea pig, horse, cat, dog, armadillo, opossum, platypus, chicken, and stickleback. (b) X. tropicalis genomic region encompassing Otop1 genes. Note the presence of two paralogous Otop1 genes (Otop1a and Otop1b), but otherwise the same general gene organization as in mouse. (c) Human genomic region encompassing OTOP1 showing the inversion separating OTOP1 and DRD5. The ~5-Mb inverted segment is flanked by large, highly similar SDs arranged in a palindromic fashion. The connecting blue lines indicate regions of paralogy between the proximal and distal duplicons (see also additional file 2 for additional pair-wise homology information). The underlying structure of each duplicon-containing region is depicted by colored vertical lines. Selected gene annotations from the UCSC Genome Browser RefSeq track are also shown: OTOP1 (red), genes residing in proximity to Otop1 in panels (a) and (b) (blue), genes within the RS447 megasatellite (green), and genes inverted in the human genome compared to species' genomes (orange). (d) Fine structure of the SDs flanking OTOP1 and the RS447 megasatellite in the human genome. Each duplicon is a mosaic of smaller duplicated segments that are labeled and colored based on their ancestral cytogenetic band of origin. Sequencing gaps in the hg17 sequence assembly of the human genome are indicated with pink lines, while the gene content is annotated below each duplicon. Note the 7E OR clusters residing at each duplicon boundary (black boxes) and palindromic configuration of the proximal and distal duplicons.
Hurle et al. BMC Evolutionary Biology 2011 11:23 doi:10.1186/1471-2148-11-23