Divergence of A and B transcripts. (A) Distribution of percent identity between A/B homoeologous genes in a set of 26 experimentally validated genes (52 homoeologs). Mean = 97.3%; SD = 1.20%. (B) Distribution of distances between 707 single nucleotide polymorphisms (SNPs) between homoeologs in tetraploid wheat coding regions. Mean = 37.8 bp; SD = 47.1 bp; Median = 27 bp.