Browsing by Author "Moutou, K. A."
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- Determinism and causative factors for morphological anomalies in reared European fishesPublication . Boglione, C.; Fontagné, Stéphanie; Gavaia, Paulo J.; Gisbert, Enric; Kjorsvik, E.; Koumoundouros, Giorgos; Moren, M.; Moutou, K. A.; Witten, PaulThe presence of sublethal morphological deformities represents one of the main bottleneck of the industrial finfish hatchery production, resulting in major economic loss due to reduced growth and marketing ability of the final product, that has to be transformed (filets) or sold for fish flour. Furthermore, the elimination of deformed fishes from the productive cycle needs for periodic selections at present carried out by manual sorting. This represents an additional economic cost, and a stress for fishes.
- Molecular cloning and sequence of gilthead sea bream (Sparus aurata) alpha-skeletal actin: tissue and developmental expressionPublication . Moutou, K. A.; Socorro, Sílvia; Power, Deborah; Mamuris, Z.; Canario, Adelino V. M.In the present study, the Sparus aurata -skeletal actin was cloned from a mixed larvae complementary DNA library. The clone isolated was 1523 bp long with an open reading frame of 1134 bp coding for a 377-amino acid protein. The deduced amino acid sequence of sea bream -actin is identical to Fugu -actin-1. The expression of -actin was initiated at the onset of segmentation. In adult fish, -actin is expressed predominantly in white and red muscle.
- Molecular cloning and sequence of Sparus aurata skeletal myosin light chains expressed in white muscle: developmental expression and thyroid regulationPublication . Moutou, K. A.; Canario, Adelino V. M.; Mamuris, Z.; Power, DeborahTwo full-length cDNA clones encoding the skeletal myosin light chain 2 (MLC2; 1452 bp) and myosin light chain 3 (MLC3; 972 bp) were isolated from a cDNA library prepared from gilthead sea bream Sparus aurata larvae. The MLC2 cDNA encoded a predicted protein of 170 residues that was 79 % identical to rabbit MLC2 over the entire length and 87 % identical within the Ca2+- binding region. The deduced amino acid sequence of MLC3 was 153 residues in length and was 91 % and 69% identical to the zebrafish and rabbit MLC3, respectively. Northern blot analysis revealed that in adults both transcripts were expressed in fast white muscle only. MLC2 appeared earlier in development: MLC2 transcripts were detectable from the beginning of segmentation, whereas MLC3 transcripts did not appear until 27 h post-fertilisation. At this developmental stage, a second MLC2 transcript of 0.89 kilobase-pairs was present. MLCs exhibited a different age-related pattern of response to varied thyroidal states, which were experimentally induced by the administration of 1 mgg-1 body mass of thyroxine (T4) or triiodothyronine (T3), or 5 ng g-1 body mass of the hypothyroidal compound thiourea; MLC3 expression was not significantly affected, whereas levels of MLC2 transcripts were significantly elevated in the white muscle only of juvenile sea bream after administration of T4. Although the mechanism of thyroidal regulation of MLC expression remains unknown, the present results suggest that different regulatory mechanisms exist for different MLCs.
- Temperature sensitivity of skeletal ontogeny in Oreochromis mossambicusPublication . Campinho, Marco António; Moutou, K. A.; Power, DeborahSensitivity of skeletal ontogenesis to temperature was assessed in Mozambican tilapia Oreochromis mossambicus and culture temperature manipulations (22, 27 and 32 C) were used to establish if age or length gave the most suitable metric for standardization. Oreochromis mossambicus larval growth was composed of two growth stanzas: an initialpe riod of rapid growth, followed by a slower growth phase. Irrespective of culture temperature chondrogenesis occurred during the first rapid growth phase and ossification was initiated during the second slower growth phase. The sequence of events and rate at which ossification occurred was much more sensitive to temperature than chondrogenesis. Cumulative counts provide a useful developmental index for skeletal ontogenesis; overall, age (effective days-degrees) gave the best estimation of developmental status during chondrogenesis and the initiation of ossification, although standard length (as log10LS) was a better metric for completion of ossification. The timing of development of functionally important structures, such asMeckel’s cartilage, the branchial arches, the centra and the cleithrum important for breathing, feeding and swimming, was well conserved at all temperatures and may be a good index of teleost developmental stages.
- What determines growth potential and juvenile quality of farmed fish species?Publication . Valente, L. M. P.; Moutou, K. A.; Conceição, L. E. C.; Engrola, S.; Fernandes, J. M. O.; Johnston, Ian A.Enhanced production of high quality and healthy fry is a key target for a successful and competitive expansion of the aquaculture industry. Although large quantities of fish larvae are produced, survival rates are often low or highly variable and growth potential is in most cases not fully exploited, indicating significant gaps in our knowledge concerning optimal nutritional and culture conditions. Understanding the mechanisms that control early development and muscle growth are critical for the identification of time windows in development that introduce growth variation, and improve the viability and quality of juveniles. This literature review of the current state of knowledge aims to provide a framework for a better understanding of fish skeletal muscle ontogeny, and its impact on larval and juvenile quality as broadly defined. It focuses on fundamental biological knowledge relevant to larval phenotype and quality and, in particular, on the factors affecting the development of skeletal muscle. It also discusses the available methodologies to assess growth and larvae/juvenile quality, identifies gaps in knowledge and suggests future research directions. The focus is primarily on the major farmed non-salmonid fish species in Europe that include gilthead sea bream, European sea bass, turbot, Atlantic cod, Senegalese sole and Atlantic halibut.