Figure 1. Alignment of 51 AmbHLH members. Designation of basic, helix 1, loop and helix 2 follows Ferre-D’Amare et al. (Ferre-D'Amare 1993). The family names and high-order groups have been organized according to Table 1 in Ledent et al (Ledent et al. 2002). AmbHLHs were named in accordance with fruit fly nomenclature.