Comparison of Tlx-related proteins. The predicted protein sequences for the chicken Tlx-1 andTlx-3 genes as well as their previously described human (Hatano et al., 1991) and/or mouse (Dear et al., 1993) homologs are aligned. The homeodomain is shaded. Four other highly conserved motifs, previously designated TH1–TH4 (Cheng and Mak, 1993), are enclosed in boxes. Amino acid identity is indicated by dots. Dashes correspond to gaps introduced to maximize alignment. The length of each protein is indicated numerically, and the position of the introns is indicated by a triangle.