Loading...
17 results
Search Results
Now showing 1 - 10 of 17
- Cloning, expression, and tissue localisation of prolactin in adult sea bream (Sparus aurata)Publication . Santos, Cecilia; Brinca, Lilia; Ingleton, P. M.; Power, DeborahA major action of prolactin (PRL) in teleost fish is the maintenance of hydromineral balance in euryhaline species in fresh water. The function of PRL in marine teleosts is less certain and unlike euryhaline teleosts, such as tilapia and salmon, there is relatively little information about protein or gene structure. Associated with studies to determine potential functions of PRL, pituitary prolactin cDNA has been cloned and sequenced from sea bream (Sparus aurata), a marine teleost. The sequence obtained spanned 1349 bp and contained an open reading frame encoding a protein of 212 amino acids composed of a putative signal peptide of 24 residues and a mature protein of 188 amino acids. N-terminal sequencing of the native protein confirmed unambiguously the cleavage site, Ala24, Val25, predicted from alignments of the sea bream PRL cDNA with that of other teleosts. The presence of only one form of PRL in sea bream was supported by identification using Northern blots of only a single transcript of 1.35 kb. Reverse transcription and polymerase chain reaction techniques coupled with Southern blot analysis resulted in the detection of PRL in the pituitary but also in the intestine, liver, ovary, and testes.
- Parathyroid hormone-related protein and somatolactin in sea bream (Sparus aurata) brain and pituitaryPublication . Ingleton, P. M.; Power, Deborah; Canario, Adelino V. M.; Martin, T. J.; Danks, J. A.Parathyroid hormone-related protein (PTHrP) and somatolactin (SL) are both peptides that have been located in PAS+ve pars intermedia (PI) cells of teleost fishes. In mammals and the chick PTHrP is a hypercalcaemic factor causing lysis of bone calcified matrix and inhibiting phosphate excretion via the kidney. Functions of PTHrP in fishes are unknown but SL stimulates phosphate re-absorption by flounder kidney tubule cells1 and low ambient calcium activates PI cells of trout pituitaries.2 It appears possible that both peptides have some similar functions. They only share incidental amino acid homologies, so we have examined brain and pituitaries of sea bream for their distribution using specific antiserum to chum salmon SL (generous gift of H. Kawauchi) and to two regions of human PTHrP (1–16 ) and (50–69).
- Cloning and characterisation of a fish aldolase B genePublication . Llewellyn, Lynda; Ramsurn, Vimi P.; Sweeney, Glen E.; Wigham, Trevor; Santos, Cecilia; Power, DeborahA full length cDNA clone representing an aldolase mRNA was isolated from a sea bream (Sparus aurutu) liver cDNA library. Sequencing of this clone revealed it to encode a 364 amino acid protein with 74% amino acid identity to human aldolase B and slightly lower similarity to human aldolase A and C. In view of the sequence data and of Northern blot analysis showing strong expression of a 1.6 kb transcript in liver it was concluded that the cloned gene represents aldolase B. This clone represents the first aldolase gene to be sequenced from any fish species thus providing new data on the evolution of the vertebrate aldolase gene family.
- Development of the pectoral, pelvic, dorsal and anal fins in cultured sea breamPublication . Faustino, M.; Power, DeborahThe pectoral fin girdle was the first element of the fins to develop in Sparus aurata. By 3·1mm LN (notochord length) the cleithrum was ossified and the cartilaginous caracoid–scapula was present. The fin was fully developed at 11·6 mm LS (standard length) and by 16·0 mm LS most elements of the fin were ossified. The pelvic fins were the last pair to develop and rudiments of these were first detected at 7·9 mm LS. The pelvic fin and girdle were completely formed and ossified at 16·0 mm LS. The development of dorsal and anal fins began at c. 6·5–7·0 mm LS with the formation of 10 cartilaginous dorsal proximal radials and eight cartilaginous ventral proximal radials. The three cartilaginous predorsals(supraneurals) appeared at 7·7 mm LS and the ossification of dorsal and anal proximal and distal radials began, respectively, at 10·5 mm LS and 11·3 mm LS. Ossified structures in the fins were also classified according to their origin, as being either dermal or endochondral. Finally the chronology of appearance of fin structures in S. aurata was compared with that reported for other Sparidae, Engraulidae and Haemulidae.
- The effect of stocking density on growth in the gilthead sea-bream, Sparus aurata (L.)Publication . Canario, Adelino V. M.; Condeça, João B.; Power, Deborah; Ingleton, P. M.The effect of stocking density on growth and size variability in gilthean sea-bream, Sprus aurata (L.) was tested by growing juveniles at densities of 0,35 kg m3, 1,3 kg m3 and 3,2 kg m3.
- Cloning, characterisation and expression of the apolipoprotein A-I gene in the sea bream (Sparus aurata)Publication . Llewellyn, Lynda; Ramsurn, Vimi P.; Wigham, Trevor; Sweeney, Glen E.; Power, DeborahA full length cDNA clone representing apolipoprotein A-I was isolated from a sea bream (Sparus aurata) liver library. The clone encodes a 261 amino acid protein which shows highest amino acid identity (38%) with salmon apolipoprotein A-I. Northern blot analysis showed strong expression of a 1.4 kb transcript in liver with lower expression in intestine. Expression of apolipoprotein A-I in intestine was markedly reduced by treatment with triiodothyronine (T3). ß 1998 Elsevier Science B.V. All rights reserved.
- Piscine (Sparus aurata) transthyretin cDNA cloning and characterizationPublication . Santos, Cecilia; Power, DeborahTransthyretin (TTR) is one of the three plasma proteins that participate in the transport of thyroid hormones, thyroxine (T4) and triiodothyronine (T3); it is also involved in the carriage of retinol through the mediation of retinol-binding protein.1 The liver and choroid plexus are the major sites of TTR synthesis in mammals, birds, and diprotodont marsupials; in reptiles, TTR is only synthesized in the choroid plexus. 2 cDNA coding for TTR has been cloned from several mammalian, reptilian, and avian species and is highly conserved especially in the domains involved in binding to thyroid hormones.3 TTR expression has never been reported in fish, in which albumin is considered to be the main carrier for T3 and T4.2 We report the cloning of a TTR cDNA from sea bream (Sparus aurata) and demonstrate the presence of TTR mRNA in the liver of this fish.
- Cloning and sequencing of a full-length sea bream (Sparus aurata) beta-actin cDNAPublication . Santos, Cecilia; Power, Deborah; Kille, Peter; Llewellyn, Lynda; Ramsurn, Vimi P.; Wigham, Trevor; Sweeney, Glen E.A full-length cDNA clone encoding beta-actin (b-actin) was isolated from a sea bream (Sparus aurata) liver cDNA library. Sequencing of this clone reveals an open reading frame encoding a 375 amino acid protein that shares a high degree of conservation to other known actins. The sea breamb-actin sequence showed 98% identity to carp and human b-actin and 95% and 94% identity to sea squirt and Dictyostelium cytoplasmic actins, respectively.
- Identification of transthyretin in fish (Sparus aurata) cDNA cloning and characterisationPublication . Santos, Cecilia; Power, DeborahTransthyretin (TTR) has been proposed to have first evolved in reptiles and is one of the three plasma proteins important in the transport of thyroid hormones in higher vertebrates.
- Development of osteological structures in the sea bream Vertebral column and caudal fin complexPublication . Faustino, M.; Power, DeborahThe development of cartilaginous structures in cultured sea bream Sparus aurata larvae and the timing of their ossification was studied. In cultivated sea bream larvae the first cartilaginous structure to be identified was hypural 1 at 4·1 mm notochord length (LN). By 5·3 mm LN, prior to the onset of ossification, it was possible to distinguish the following cartilaginous structures: all 23 neural arches, all 13 haemal arches and two of the four pairs of parapophyses. The neural arches 1–4 and 15–23 were formed on the notochord and elongated dorsally, while neural arches 5–14 appeared on the dorsal side of the spinal cord and elongated ventrally. Initiation of ossification occurred at 5·7–6·0 mm standard length (LS) when the cartilaginous ontogeny of the vertebral column was completed. Ossification was coincident with dorsal flexion at the posterior end of the notochord and occurred in a sequential manner: (1) dorsoanteriorly, the cartilaginous neural arches and the centra were the first structures to ossify; (2) ventrad at the centre, at 7·0–7·5 mm LS; (3) posteriorly at 7·1 mm LS the hypural complex and urostyle (24th centrum) were ossified; and (4) dorsad at the centre (neural arches and spines).