Temperature and the expression of myogenic regulatory factors (MRFs) and myosin heavy chain isoforms during embryogenesis in the common carpCyprinus carpioL.

Abstract

4239The myogenic regulatory factors (MRFs) are a family of basic helix-loop-helix (bHLH) transcription factors essential to the specification and determination of the muscle cell Supplementary material available online at

Somite formation and expression ofMyoD,myogeninandmyosinin Atlantic halibut (Hippoglossus hippoglossusL.)embryos incubated at different temperatures: transient asymmetric expression ofMyoD

“…Temperature has been shown to affect the sequence of organogenesis (Johnston et al, 1995), rate of somitogenesis (Brooks and Johnston, 1994) (present study), number of somites (Brooks and Johnston, 1994), number and size of muscle fibres at hatching (Vieira and Johnston, 1992;Brooks and Johnston, 1993;Usher et al, 1994;Nathanailides et al, 1995;Johnston and McLay, 1997;Alami-Durante et al, 1997;Galloway et al, 1998;Galloway et al, 1999; and the relative timing of myofibrillogenesis (Johnston et al, 1995) in different fish species. However, in agreement with our halibut study, relative temporal and spatial expression of several muscle genes in Atlantic herring Clupea harengus (Temple et al, 2001), Atlantic cod Gadus morhua and common carp Cyprinus carpio (Cole et al, 2004) do not seem to be influenced by temperature. Temple et al concluded (Temple et al, 2001) that temperature probably affects myofibril synthesis downstream from MyHC transcription, at the translation or assembly stage.…”

“…In most fish species where MyoD has been studied to date [zebrafish Danio rerio (Weinberg et al, 1996); Atlantic herring (Temple et al, 2001); gilthead seabream (Tan and Du, 2002); common carp (Cole et al, 2004); rainbow trout (Delalande and Rescan, 1999;Xie et al, 2001); flounder Paralichthys olivaceus (Zhang et al, 2006)], the gene is expressed in presomitic and somitic adaxial cells, which will later become the superficial slow red muscle fibres (Devoto et al, 1996). Subsequently, MyoD is expressed in lateral cells of the somites, which will form the bulk of the fast white muscle mass.…”

“…The resulting heterodimer has a high affinity for the consensus E-box motif CANNTG located in the promoter or the enhancer of the majority of muscle-specific genes and thereby promotes the transcription of these target genes (Ma et al, 1994;Puri and Sartorelli, 2000). During the embryonic development of most fish species, MyoD is first present in adaxial cells of the presomitic mesoderm (Weinberg et al, 1996;Delalande and Rescan, 1999;Temple et al, 2001;Xie et al, 2001;Tan and Du, 2002;Cole et al, 2004;Zhang et al, 2006), showing that some mesodermal cells are destined to become muscle cells very early in organogenesis. The adaxial cells will later become myoblasts, migrate and mature into slow superficial red muscle fibres, whereas the lateral cells of the somites form the bulk of fast white muscle fibres (Devoto et al, 1996).…”

“…Egg incubation temperature affects the size and number of red and white muscle fibres at hatching, as well as muscle growth throughout larval and juvenile life in many fish species (Stickland et al, 1988;Vieira and Johnston, 1992;Brooks and Johnston, 1993;Usher et al, 1994;Johnston et al, 1995;Nathanailides et al, 1995;Johnston and McLay, 1997;Alami-Durante et al, 1997;Johnston et al, 1998;Galloway et al, 1998). By contrast, gene expression of the MRFs is affected by temperature in some fish species Xie et al, 2001) but not in others (Temple et al, 2001;Cole et al, 2004).…”

Post-genomic approaches to understanding the mechanisms of environmentally induced phenotypic plasticity

“…These cold-specific isoforms have properties that increase performance in the cold, perhaps due to possession of a more flexible protein structure. Cold also causes significant changes to the expression of myogenic regulatory factors during embryogenesis and development (Cole et al, 2004) and following the restoration of warm conditions in cold-acclimated adult carp (Kobiyama et al, 2000). These might be important in specifying the different muscle phenotypes in the cold.…”