1396 I. A. JOHNSTON, V. L. A. VIEIRA AND M. ABERCROMBY. A. 5 °C nt sf a g nt ff ov e h ys ph nt nt sc pda pda sf sf e g hov nt ff ys ph e a g h ys ov nt ff g g ph.
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The Journal of Experimental Biology 198, 1389–1403 (1995) Printed in Great Britain © The Company of Biologists Limited 1995
TEMPERATURE AND MYOGENESIS IN EMBRYOS OF THE ATLANTIC HERRING CLUPEA HARENGUS IAN A. JOHNSTON1,2, VERA. L. A. VIEIRA1,* AND MARGUERITE ABERCROMBY1 Marine Laboratory, School of Biological and Medical Sciences, University of St Andrews, St Andrews, Fife KY16 8LB, Scotland and 2Dunstaffnage Marine Research Laboratory, PO Box 3, Oban, Argyll PA34 4AD, Scotland 1Gatty
Accepted 27 February 1995
Summary The development of axial muscles has been investigated development temperature. For rostral myotomes, the in spring-spawning Atlantic herring (Clupea harengus L.) synthesis of contractile filaments and myofibril assembly reared at 5, 8, 12 and 15 ˚C. In 1994, around 90 % of were first observed at the 42-, 38- and 27-somite stages at 5, 8 and 12 ˚C, respectively. The differentiation of myotubes embryos hatched after 28 days at 5 ˚C, 16 days at 8 ˚C, 9 into morphologically recognisable muscle fibre types first days at 12 ˚C and 8 days at 15 ˚C. The somites were formed occurred at the 62-somite stage at 5 ˚C, at the 48-somite from cells of the paraxial mesoderm in a rostral to caudal direction, starting at the neural plate stage. Somites were stage at 8 ˚C and as early as the 40-somite stage at 12 ˚C. added at rates ranging from one every 3 h at 5 ˚C to one Cell proliferation experiments with 5-bromo-29deoxyuridine showed that another population of myoblasts every 52 min at 15 ˚C. A small number of myoblasts, was activated on the surface of muscle fibres just prior to located adjacent and lateral to the notochord, elongated to hatching. Development temperature also affected muscle span the somite to form mononuclear myotubes. The cellularity; there were 43 % more inner muscle fibres in the majority of muscle fibres were formed by the fusion of 2–5 myotomes of 1-day-old larvae reared at 12 ˚C than at 5 ˚C myoblasts to produce multinucleated myotubes that (P
