Three in frame termination codons have been introduced into the dec-1 coding sequence, such that the fc177-specific open reading frame is truncated at residue R1030, 45 amino acid residues into the 604 residues fc177-specific C-terminus.

The addition of dec-1^fc177TAAG doers not rescue the chorion ultrastructure defects seen in dec-1²⁹ and dec-1² eggshells, but also fails to rescue the female fertility phenotype.