Differentiation and growth of muscle in the fish Sparus aurata (L): I. Myosin expression and organization of fibre types in lateral muscle from hatching to adult

Abstract

Post-hatching development of lateral muscle in a teleost fish, Sparus aurata (L) was examined. At hatching only two fibre types were present, several layers of mitochondria-poor, myofibril-rich deep muscle fibres surrounded the notochord and were covered by a superficial monolayer of mitochondria-rich, myofibril-poor A third ultrastructurally distinct fibre type first appeared as one or two fibres located just under the lateral line at 6 days post-hatching. This type, which gradually increased in number during larval life, contained a slow isoform of myosin, identified by mATPase staining and immunostaining with myosin isoform-specific antibodies. Deep muscle fibres--the presumptive fast-white type--contained a fast myosin, and superficial monolayer fibres an isoform similar but not identical to that in adult pink muscle fibres. The only fibres present during larval life which showed a clear change in myosin expression were the superficial monolayer fibres, which gradually transformed into the slow type post-larvally. Pink muscle fibres first appeared near the end of larval life. Both slow and pink muscle fibres remained concentrated around the horizontal septum under the lateral line during larval life, expanding outwards towards the apices of the myotomes only after metamorphosis. Between 60 and 90 days very small diameter fibres with a distinct mATPase profile appeared scattered throughout the deep, fast-white muscle layer, giving it a 'mosaic' appearance, which persisted into adult life. A marked expansion in the slow muscle layer began at the same time, partly by transformation of superficial monolayer fibres, but mainly by addition of new fibres both on the deep surface of the superficial monolayer and close to the lateral line. The order of appearance of these fibre types, their myosin composition, and the significance of the superficial monolayer layer are discussed and compared to muscle fibre type development in higher vertebrates.

Muscle differentiation in blackspot seabream (Pagellus bogaraveo, Brunnich): Histochemical and immunohistochemical study of the fibre types

“…The definitive slow-red muscle was formed gradually due to the combined mechanism of hyperplastic growth forming new slow-red fibres with additional conversion of all the monolayer fibres into slow-red muscle fibres, a phenomenon already described in other species (Scapolo et al, 1988;Veggetti et al, 1993;Mascarello et al, 1995;Patruno et al, 1998).…”

“…The latter extended into the edges of the hypo-and epaxial regions and represented the only muscle layer of the most caudal myomeres, as observed in Sparus aurata by Mascarello et al (1995). At hatching, the superficial monolayer was already differentiated from the deep muscle with regard to its myosin composition (compare LSM and LW profiles in Table 1), although neither resembled the adult types.…”

“…An external cell origin of the new slow muscle fibres emerging from the lateral surface next to the lateral line nerve was supposed by several authors in different fish species as Danio rerio (Waterman, 1969), Clupea harengus (Linnaeus) (Johnston, 1993), Dicentrarchus labrax (Linnaeus) and Sparus aurata (Linnaeus) (Veggetti et al, 1990;López-Albors et al, 1998). As seen in other fish (Scapolo et al, 1988;Mascarello et al, 1995;Patruno et al, 1998), the appearance of those fibres coincided with the first attempts of the larvae at cruise swimming in search for food, and may be an important factor in larval survival at that age.…”

“…The combination of very alkali-stable ATPase, strong reaction with 3/96 (specific for fish fast myosin) and an intermediate staining for SDH is typical of intermediate-pink fibres in many (although not all) fish species (e.g., as reviewed by, Mascarello et al, 1986Mascarello et al, , 1995Sänger and Stoiber, 2001). The strong reaction observed in the intermediate-pink fibres with the antibody for fish fast myosin is in accordance with the recent results obtained in the Steinbacher et al (2006) study.…”

Advances in research on the prenatal development of skeletal muscle in animals in relation to the quality of muscle-based food. I. Regulation of myogenesis and environmental impact

“…Similarly, the distinctive phases of muscle development in fish are underpinned by molecular changes that probably better adapt muscle function to changing physiological requirements during development (Chauvigné et al, 2006;Campinho et al, 2007;Rescan, 2008). The red and white muscle fibres in fish are arranged in discrete anatomical regions (Bone, 1978;Mascarello et al, 1995;Moutou et al, 2005;Silva et al, 2008) largely located in the hypaxial and epaxial muscles along the length of the body and represent 40% to 60% of body mass. Moreover, as fish are poikilotherms and do not regulate body temperature, changes in environmental temperature can have a profound impact on the rate of myogenesis, composition of sub-cellular organelles, patterns of gene expression and the number and size distribution of muscle fibres (reviewed by Johnston, 2006).…”