Tracks are numbered on the left and syntenic alignments across the human chromosome are shown in the top five tracks: (1) human-chicken; (2) human-rat; (3) human-mouse; (4) human-dog; and (5) human-chimpanzee. The inter- and intrachromosomal breakpoints are represented by red and blue gaps, respectively. Cyan gaps indicate regions without sequence alignment and the centromere is located in the cyan gap that is common to all species. Pink brackets indicate sequence inversions. The density of recent segmental intra- and interchromosomal duplications from low-copy repeats is shown in tracks (6) and (7). The incidence of major interspersed (high-copy) repeats are depicted in tracks (8), (9) and (10) for LINEs, LTRs and SINEs, respectively. The variations in G+C content, and densities of CpG islands, genes and pseudogenes appear in tracks (11), (12), (13) and (14), respectively, whereas gene paralogue density, gene density and gene variant density appear in tracks (15), (16) and (17), respectively. Gene density in track 13 is from UCSC 'known genes', whereas track 16 reflects the non-redundant locus annotations detailed in this study. ( The above image is linked t o the Human Chr 3 annotation data deposited in Genboree. )