Structural aspects of galectins from mammals and invertebrates. (A) Sequence alignment of the carbohydrate-recognition domain (CRD) regions from bovine galectin-1, zebrafish Drgal1-L2, C. elegans N16, and the CRDs 1–4 of CvGal1. (B) Homology modeling of the CRDs from CvGal1: bovine galectin-1, CRD-1, -2, -3, and -4 are shown in white, blue, yellow, red, and green, respectively. Numbering of amino acid residues is based on bovine galectin-1. The solid arrow shows loop 4 of CvGal1 CRD-2, 3, 4, whereas a dashed arrow shows loop 4 of CRD-1. (White ribbon) loop 4 in bovine galectin-1; (solid arrow) short loop 4 in Crassotrea virginica CvGal1 CRDs 1,2,3,4; (dotted arrow) short loop 4 in C. elegans N16.