Global alignment of 10-kb sequences around each NBS gene between paralogous clusters. (A) Comparison between NBS427 in the chr13:21.5..21.9 Mb cluster and three NBS genes (NBS358, 359, 360) in the chr13:11.8..12.2 Mb cluster. Comparison with NBSc, the most closely related full length paralogue of the truncated NBS358, is included as the most reliable approximation of how NBS358 should have appeared before the Gypsy insertion in the LRR of NBS358 and the partial degeneration of the N terminus. (B) Comparison within chr13:11.8..12.2 Mb cluster between the three NBS genes 358, 359, and 360 (comparison with NBSc, the full length paralogue of the truncated NBS358, is included). (C) Comparison between each pair of the most closely related paralogous NBS genes between the chr13:11.8..12.2 Mb cluster and the REN1 interval. NBS425 from the chr13:21.5..21.9 Mb cluster is included in the comparison with NBSg because its paralogue in the chr13:11.8..12.2 Mb cluster has largely degenerated. The conserved blocks of nucleotide sequences and the corresponding levels of identity were calculated with LAGAN and drawn with VISTA. The coding regions corresponding to the coiled coil (orange), NBS (green), and LRR (yellow) domains are indicated by coloured bars. The NBS domain was defined as the portion comprised from the P-loop to the MHDV motif. The insertion of repetitive elements is indicated by pink bars with the identifier of the gene in which it occurred. NBSg, NBS425, and relicts of their paralogue in the chr13:11.9..11.95 Mb region are in the opposite orientation with respect to other NBS genes. DNA sequences are represented from left to right, according to the top-to-bottom orientation of the assembled genome sequence along chr13. All protein coding sequences, with the exception of NBSg, are represented in an N- to C-terminus orientation from right to left.