Transient expression analysis of saMSTN-2 promoter activity in zebrafish embryos. The DNA construct saMSTN-2b promoter (1324/22)/GFP was injected into zebrafish zygotes at 1-2 cell stages. GFP expression was analyzed at 24 and 48–50 hpf. A mosaic pattern of expression was observed. A, B. GFP in neural crest of 24 hpf embryos, shown in dorso-lateral view by direct visualization of live embryos under bright field (A) and fluorescence (B) stereoscope. C, 50 hpf live embryos showing GFP expression in otic epithelium (white arrowhead), forebrain (blue arrowhead) and near the developing head musculature (red arrowhead). D, GFP expression in myofibers at 48 hpf (live embryos). E–G. GFP immunodetected in 50 hpf embryos in myofibers (arrowheads, E), near the eye (arrowheads, F) and near the heart (arrowheads, G). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Expression of saMSTN-2 gene in brain and muscle of S. aurata fish. Total RNA from four brains (#8G, 26G, 23C and 33C) and four muscle samples (#1G, 1F, 3F and 3S) was reverse-transcribed using oligo(dT) and subjected to PCR amplification of MSTN-2. β-actin was used as a control for absence of genomic DNA in the RNA samples. Genomic DNA from four fish was amplified using the same primers for MSTN-2 and β-actin. Amplified products were analyzed on 1-1.5% agarose gels and photographed under UV illumination following staining with ethidium bromide.