Patterns of intron within the basic and hinge regions of the bZIP domains of BdbZIP proteins. Intron patterns (a–h) are depicted. The number of introns and the number of BdbZIP proteins having a particular pattern are also indicated. P0 and P2 indicate the splicing phases of the basic and hinge regions of the bZIP domains. P0 represent the intron splicing site between codons, P2 means the intron splicing site locating between the second nucleotide and the third nucleotide in one codon.