Amino acid replacement: C53F.
Nucleotide substitution: G158T.
Adults carrying fz68G2.Act5C in a fz21 background have an average of 2.7 +/- 0.5 extra tarsal joints in the leg compared to wild type.
fz68G2.Act5C partially rescues the wing margin phenotype of fz21 fz2C1 double homozygous clones.