The images are lateral views of embryos stained by in situ hybridization using anti-sense RNA (a–e, k-o) or sense RNA (f–j, p–t) for ewsr1a and ewsr1b. The ewsr1a and ewsr1b were expressed ubiquitously at 4 cell (a and k), 256 cell (b and l), shield (c and m), 5 somite stage (d and s) and 24hpf (e and t). asRNA: anti-sense RNA, sRNA: sense RNA