title: Transient up- and down-regulation of expression of myosin light chain 2 and myostatin mRNA mark the changes from stratified hyperplasia to muscle fiber hypertrophy in larvae of gilthead sea bream (Sparus aurata L.).
abstract: Hyperplasia and hypertrophy are the two mechanisms by which muscle develops and grows. We study these two mechanisms, during the early development of white muscle in Sparus aurata, by means of histology and the expression of structural and regulatory genes. A clear stage of stratified hyperplasia was identified early in the development of gilthead sea bream but ceased by 35 dph when hypertrophy took over. Mosaic recruitment of new white fibers began as soon as 60 dph. The genes mlc2a and mlc2b were expressed at various levels during the main phases of hyperplasia and hypertrophy. The genes myog and mlc2a were significantly up-regulated during the intensive stratified formation of new fibers and their expression was significantly correlated. Expression of mstn1 and igf1 increased at 35 dph, appeared to regulate the hyperplasia-to-hypertrophy transition, and may have stimulated the expression of mlc2a, mlc2b and col1a1 at the onset of mosaic hyperplasia. The up-regulation of mstn1 at transitional phases in muscle development indicates a dual regulatory role of myostatin in fish larval muscle growth.
authors.affiliation: Department of Biochemistry & Biotechnology, University of Thessaly, Ploutonos 26, Larissa, Greece.
authors.forename: Stella
authors.initials: S
authors.lastname: Georgiou
authors.affiliation: UR 1067 Nutrition Métabolisme Aquaculture, INRA, Aquapôle, F-64310, Saint-Pée-sur-Nivelle, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Alami-Durante
authors.affiliation: Centre of Marine Sciences (CCMar), Universidade do Algarve, Faro, Portugal.
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Power
authors.affiliation: Institute of Marine Biology & Genetics, Hellenic Centre for Marine Research, Heraklion, Crete, Greece.
authors.forename: Elena
authors.initials: E
authors.lastname: Sarropoulou
authors.affiliation: Department of Biochemistry & Biotechnology, University of Thessaly, Ploutonos 26, Larissa, Greece.
authors.forename: Zissis
authors.initials: Z
authors.lastname: Mamuris
authors.affiliation: Department of Biochemistry & Biotechnology, University of Thessaly, Ploutonos 26, Larissa, Greece. kmoutou@bio.uth.gr.
authors.forename: Katerina A
authors.initials: KA
authors.lastname: Moutou
mesh_terms: D000818:Animals; D024722:Cardiac Myosins / Q000235:genetics* / Q000378:metabolism; D016000:Cluster Analysis; D015536:Down-Regulation / Q000235:genetics*; D006984:Hypertrophy; D007814:Larva / Q000235:genetics / Q000254:growth & development; D024510:Muscle Development / Q000235:genetics; D018485:Muscle Fibers, Skeletal / Q000378:metabolism* / Q000473:pathology*; D018994:Myosin Light Chains / Q000235:genetics* / Q000378:metabolism; D055435:Myostatin / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D021541:Sea Bream / Q000235:genetics* / Q000254:growth & development; D018709:Statistics, Nonparametric; D015854:Up-Regulation / Q000235:genetics*
chemical_list: D018994:Myosin Light Chains; D055435:Myostatin; D012333:RNA, Messenger; C107184:myosin light chain 2; D024722:Cardiac Myosins
keywords: Gene markers; Gilthead sea bream; Muscle cellularity; Myogenic factors; mlc2