Fig. 3.

Emergence of large NLR gene families by retroduplication. a Intact NB-ARC domains of retroduplicated and normal NLRs are used for the phylogenetic tree construction as previously described method [21]. Each color of the phylogenetic tree indicates each subgroup. b The bar graph indicates the number of retroduplicated NLRs in each subgroup. The x- and y-axes indicate the numbers of genes and subgroups, respectively. c, d The exon lengths and the numbers of normal and retroduplicated NLRs are depicted. c The x- and y-axes indicate the normal and retroduplicated NLR groups and their exon lengths, respectively. d The x- and y-axes mean the groups of NLRs and the exon numbers, respectively