Dot-plot analyses of Chr4.003.105. (A) The TRB locus region of Chr4.003.105. The multiplicity of diagonal lines parallel to the main diagonal present in the regions containing i) the TRBV 6 and 9 genes and ii) the TRBV 18, 19, 20 and 21 genes shows that these regions have been subjected to numerous duplication events. The clear cruciform area in the TRBV 6 and 9 region (also in (B)) reflects an 35 Kb area of undetermined sequence. (B) The TRBV 6 and 9 region of Chr4.003.105. Various duplicated regions of ~7 Kb to ~31 Kb and including multiple TRBV6 (black) and TRBV9 (red) genes are evident. (C) The TRBV18, 19, 20 and 21 region of Chr4.003.105. The pattern of parallel lines in this dot-plot analysis indicates a region of DNA that includes a TRBV21, 18, 19 and 20 genes that has been duplicated twice, giving rise to 3 homology units.
Connelley et al. BMC Genomics 2009 10:192 doi:10.1186/1471-2164-10-192