Amino acid replacement: C53Y.
Nucleotide substitution: G158A.
Adults carrying fz70A2.1.Act5C in a fz21 background have an average of 3.5 +/- 0.5 extra tarsal joints in the leg compared to wild type.
fz70A2.1.Act5C shows poor rescue of the wing margin phenotype of fz21 fz2C1 double homozygous clones.