NC1 hexamers were excised from animal basement membranes and analyzed by SDS/PAGE as shown in Fig. 1 A and B. The dimeric subunits, which indicate the presence of the bond, were found in nine major eumetazoan phyla. Among eight cnidarians investigated, only Hydra NC1 lacked dimeric subunits. All NC1s were immunoblotted against the rat monoclonal antibody, JK2, except for C. elegans (rabbit polyclonal; NW-154) and Drosophila (mouse monoclonal; 6G7). Black outlines indicate the locations of cropping for blot images.