Expression of myofibrillar proteins and parvalbumin isoforms during the development of a flatfish, the common sole Solea solea:: comparison with the turbot Scophthalmus maximus

Developmental changes in myofibrillar protein and parvalburnin isoform composition were investigated in the myotomal muscle of the flatfish Solea solea, characterized by a very brief metamorphic stage. Results were compared with previously obtained data on another pleuronectiform teleost, the turbot (Scophthalmus maximus), displaying prolonged metamorphosis. Electrophoretically measurable changes in myofibrillar proteins and parvalbumins were detected late in the sole, after completion of metamorphosis. In the course of development, muscles showed the usual sequential synthesis of isoforms of the myofibrillar proteins myosin light chain LC2, troponin-T, and troponin-i. An adult parvalburnin isoform (PA III) was found to predominate during sole growth. The two flatfish were characterized by highly species- specific parvalbumin isoforms. Compared with turbot, the profiles of the myofibrillar subunits and parvalburnin isoforms varied little in the course of sole development. The early appearance of adult traits might be correlated with the brevity of metamorphosis of this fish. (C) 2003 Elsevier Science Inc. All rights reserved.