Fig. 5

Effects of MYH_M743-2 promoter deletions on EGFP expression in the myotomal compartments of zebrafish embryos and larvae. A: Schematic representations of consensus-binding sites within 2075-bp upstream region of torafugu MYH_M743-2, as well as a deletion series in the torafugu MYH_M743-2 promoter region. Vertical lines represent consensus-binding sites for transcriptional factors of MEF2, MyoD and SRF. All promoter deletions (black lines) are linked to EGFP and SV40-polyA sequence in pT2AL200R150G vector. B: Bar graph showing percentages of embryos that express EGFP in the myotomal compartments in microinjection of each deletion construct. The total number of embryos injected with each construct is shown in parentheses. C–G: Embryos injected with a series of distal promoter deletion constructs at one- or two-cell stages were examined for transient EGFP expression at 1–2 dpf using fluorescent microscopy. Reduced EGFP fluorescence typically correlates with a smaller MYH_M743-2 promoter (C–F) and no EGFP expression was observed in P448 (G). An arrowhead indicates a single fiber expressing EGFP in P468 (F). Scale bars: 100 μm. H: 20 nucleotides spanning the region from - 468 to - 449 contain positive cis-elements required for MYH_M743-2 expression. Blue color with bold face in the SRF sequence indicates a central core sequence. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)