Phylogenetic analysis and gene structure of B3 domain containing genes in cacao. A. Unrooted neighbor-joining consensus tree of full-length amino acid sequences of selected Arabidopsis and Theobroma cacao B3 domain containing genes. The scale bar represents 0.2 estimated substitutions per residue and values next to nodes indicate bootstrap values from 1000 replicates. Five families of B3 domain containing genes were identified. The gene most closely related to AtLEC2 (underlined) was designated as TcLEC2. B. Comparison of TcLEC2 and AtLEC2 gene structures. Boxes represent exons and lines indicate introns. Location of the conserved B3 domain is indicated. C. Amino acid alignment of B3 domains from TcLEC2, AtLEC2, AtFUS3, and AtABI3. Residues in black boxes are identical in all four proteins; residues in dark grey boxes are identical in three of four proteins; residues in light grey boxes are identical in two of four proteins.