Fig. 5. Comparison of MyoD, myogenin and MyHC RNA transcript expression in herring embryos with similar numbers of somites and at a variety of rearing temperatures. (A–E) Expression of MyoD, (F–J) expression of myogenin, (K–O) expression of myosin heavy chain. (A,F) Embryos, dorsal view, head positioned towards the bottom of the figure. All other embryos are positioned anterior to the right. (A,F,K) 15-somite embryos. (B,G,L), 18-, 17- and 18-somite embryos, respectively. (C,H,M), 35-, 34- and 34-somite embryos, respectively. (D,I,N), 49-, 46- and 48-somite embryos, respectively. (E,J,O) Embryos with almost complete segmentation. Arrows indicate adaxial cells; the arrowhead indicates unstained somites. Scale bars, 300 µm.