Mesoderm tissues are mis-specified in the secondary tails of mfn. (A-J) Lateral view of expression of col2a (col2α; A,B), myoD (C,D), neurog1 (E,F), ntl (G,H) and tbx6 (I,J) in the posterior tail of wild-type and mfn zebrafish embryos. At 26 hpf, col2a (B), myoD (D) and ntl (H) are ectopically expressed in the secondary tail, but neurog1 is not (F). At 24 hpf, tbx6 (J) is also ectopically expressed in the secondary tail. Embryos in all images are mounted with anterior to the left. Dotted line in F indicates secondary tail.