A Classification of Basic Helix-Loop-Helix Transcription Factors of Soybean

Figure 2

Conservation of intron position within the bHLH domain of soybean bHLH genes. Representative bHLH sequences are shown with the positions of three typical bHLH introns (pattern A) marked and the number of genes (99) that fit this pattern. Other bHLH genes have a subset of these three introns (patterns B–E). An alternative pattern F contains one intron at a different location. The genes with pattern G have two other conserved introns, and pattern H has only the first of these introns. 39 of the soybean bHLH genes have no introns within the bHLH domain. Three other bHLH genes exhibit a different intron-exon pattern. The specific domains shown are as follows (A–I): GmbHLH234, GmbHLH183, GmbHLH253, GmbHLH136, GmbHLH289, GmbHLH77, GmbHLH145, GmbHLH84, and GmbHLH98. Intron patterns for all soybean bHLHs are located in Additional File 1.