Structure prediction for RTTN : a well-folded globular part (armadillo-like repeats, aa 1 – 120) and an unstructured linker (aa 121 – 166). The protein chain is colored from blue (N-terminus) to red (C-terminus). α-helices are shown as ribbons. Side chains of residues substituted because of SNPs are shown in the "spacefill" representation and labeled; C, O, and N atoms are shown in gray, red, and blue, respectively. The positions of amino acid changes and the medaka populations sharing these changes are as follows: aa78, Thr: E.KOR, Ala: Others; aa92, Ser: S.JPN, Leu: Others; aa95, Arg: Akishima, Pro: Others; aa102, Gln: Miyatsu, Arg: Others, aa135, Leu: Sabae, Pro: Others; aa140, Lys: E.KOR, Asn: Others; aa143, Thr: E.KOR, N.JPN, Lys: W.KOR & China, and S.JPN; aa158, Ala: N.JPN, Pro: Others.