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Fig. S13 Pax7 proteins are not required for MRF gene expression and subsequent hypaxial and oesophageal striated muscle formation. Immunodetection of Pax7 (A) and sarcomeric MyHC (D) or in situ mRNA hybridization for myod (B) and myog (C). Lateral view wholemounts have anterior towards the left and dorsal towards the top (A-C, left panels; D). Dorsal view wholemounts have anterior towards the left (B and C, right panels). (A) Nuclear Pax7 proteins accumulate weakly in dermomyotome cells (white arrows) and strongly in xanthophores (black arrows) overlying the somites at 26 hpf. Whereas pax7a MO diminishes dermomyotomal Pax7, both pax7a and pax7b MOs are required to remove all immunodetection. (B,C) Injection of dual pax7a+pax7b MOs has no discernible effect upon either myod (B) or myog (C) mRNA accumulation in anterior or posterior hypaxial muscle anlage or pectoral fin at 50 hpf (yellow, white and green arrowheads, respectively). (D) At 96 hpf, sarcomeric MyHC had accumulated in OSM (red markers) and extended caudally in both control and pax7a+pax7b morphant animals.