ZFIN is incorporating published figure images and captions as part of an ongoing project. Figures from some publications have not yet been curated, or are not available for display because of copyright restrictions.

Organism and tissue-level characterisation of the ky^yo1/ky^yo1 zebrafish shows no overt pathology. (A) Longitudinal growth study shows no difference in ky^yo1/ky^yo1 zebrafish morphology. Three metrics were assessed in WT and ky^yo1/ky^yo1 zebrafish at 2, 3 and 4 months post-fertilisation: length (blue) from the jaw to the anterior of the tail fin, height (green) at the anterior of the anal fin, and tail area (red) measured between the anterior of the anal fin and the anterior of the tail fin. No differences were seen between WT and ky^yo1/ky^yo1 zebrafish. (B) Representative transverse sections of 3-month-old zebrafish show muscle fibres in cross-section. A small number of very small fibres and fibres with centralised nuclei can be seen with similar frequency in both WT and ky^yo1/ky^yo1 fish (examples indicated by yellow arrows), indicating that these are not pathological changes. (C) Slow muscle distribution is preserved in the ky^yo1/ky^yo1 zebrafish. Immunofluorescence against the slow-muscle marker (s58) on transverse sections shows that slow muscle remains restricted laterally in the ky^yo1/ky^yo1 zebrafish. Image representative of sections from two WT and two ky^yo1/ky^yo1 fish at 6 months post-fertilisation. As sections are derived from different positions on the anterior-posterior axis, slow-muscle area and cell number cannot be directly compared.

ZFIN is incorporating published figure images and captions as part of an ongoing project. Figures from some publications have not yet been curated, or are not available for display because of copyright restrictions.

Methylcellulose challenge does not increase transcriptional upregulation of CASA in ky^yo1/ky^yo1 embryos. (A) qPCR of bag3, flnca and flncb shows significantly increased transcription in 5 dpf ky^yo1/ky^yo1 embryos compared with WT controls when grown in normal (E3) media (one-way ANOVA/Dunnett's; *P<0.05, **P<0.01, n=3). Swimming in media enriched with 1% methylcellulose (Me) from 3 dpf to 5 dpf induces significant increases in bag3 and flnca transcription and reveals a trend towards increased flncb transcription in WT embryos (one-way ANOVA/Dunnett's; *P<0.05, **P<0.01, n=3). No significant changes in transcription are observed between challenged and unchallenged ky^yo1/ky^yo1 embryos. Error bars indicate s.e.m. (B) Fibre-typing of embryonic zebrafish muscle shows no changes to slow (green) or fast (red) muscle distribution. Images are representative of five WT and four ky^yo1/ky^yo1 embryos per treatment group (see Fig. S4 for full panel). (C) Representative images of birefringence analysis of whole zebrafish embryos, showing no gross muscle damage or deformation in any treatment group. These observations indicate that transcriptional changes are not secondary to gross muscle damage.

Neither ky deficiency or methylcellulose challenge induces changes in fast/slow muscle distribution in zebrafish embryos.

Full panel of sections represented in figure 6C. Fibre-typing of transverse sections of embryonic zebrafish muscle shows no changes to slow (green) or fast (red) muscle distribution in any of the treatment groups (WT/ WT + methylcellulose/ kyyo1/kyyo1 / kyyo1/kyyo1 + methylcellulose), indicating shifts in flnc isoform expression cannot be explained by fibre-type shifting.