Fluorophore insertion sites in the C. elegans type IV collagen α-chains. The schematic illustrates C. elegans type IV collagen α-chains EMB-9 and LET-2 with the N-terminal 7S domains, the triple helical regions, and the C-terminal NC1 domains annotated above the proteins. Arrowheads mark fluorophore insertion sites. Each site is labeled with the fluorophores that were inserted at the location and whether the fluorophore was flanked by a linker sequence (thin black wavy lines; see Fig. S1 A). Insertions that were homozygous-inviable are denoted.