Institute Acuicultura Of Torre Of La Sal

Aldeadávila de la Ribera, Spain

Institute Acuicultura Of Torre Of La Sal

Aldeadávila de la Ribera, Spain
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Escobar S.,Institute Acuicultura Of Torre Of La Sal | Felip A.,Institute Acuicultura Of Torre Of La Sal | Gueguen M.-M.,University of Rennes 1 | Zanuy S.,Institute Acuicultura Of Torre Of La Sal | And 3 more authors.
Journal of Comparative Neurology | Year: 2013

Kisspeptins are now considered key players in the neuroendocrine control of puberty and reproduction, at least in mammals. Most teleosts have two kiss genes, kiss1 and kiss2, but their sites of expression are still poorly documented. As a first step in investigating the role of kisspeptins in the European sea bass, a perciform fish, we studied the distribution of kiss1 and kiss2-expressing cells in the brain of males and females undergoing their first sexual maturation. Animals were examined at early and late in the reproductive season. We also examined the putative expression of estrogen receptors in kiss-expressing cells and, finally, we investigated whether kisspeptins are expressed in the pituitary gland. We show that kiss1-expressing cells were consistently detected in the habenula and, in mature males and females, in the rostral mediobasal hypothalamus. In both sexes, kiss2-expressing cells were consistently detected at the level of the preoptic area, but the main kiss2 mRNA-positive population was observed in the dorsal hypothalamus, above and under the lateral recess. No obvious sexual differences in kiss1 and kiss2 mRNA expression were detected. Additional studies based on confocal imaging clearly showed that most kiss1 mRNA-containing cells of the mediobasal hypothalamus strongly express ERα and slightly express ERβ2. At the pituitary level, both sexes exhibited kiss1 mRNA expression in most FSHβ-positive cells and never in LHβ-positive cells. © 2012 Wiley Periodicals, Inc.

Guillot R.,Institute Acuicultura Of Torre Of La Sal | Ceinos R.M.,CSIC - Institute of Marine Research | Cal R.,Spanish Institute of Oceanography | Rotllant J.,CSIC - Institute of Marine Research | Cerda-Reverter J.M.,Institute Acuicultura Of Torre Of La Sal
PLoS ONE | Year: 2012

While flatfish in the wild exhibit a pronounced countershading of the dorso-ventral pigment pattern, malpigmentation is commonly observed in reared animals. In fish, the dorso-ventral pigment polarity is achieved because a melanization inhibition factor (MIF) inhibits melanoblast differentiation and encourages iridophore proliferation in the ventrum. A previous work of our group suggested that asip1 is the uncharacterized MIF concerned. In order to further support this hypothesis, we have characterized asip1 mRNAs in both turbot and sole and used deduced peptide alignments to analyze the evolutionary history of the agouti-family of peptides. The putative asip precursors have the characteristics of a secreted protein, displaying a putative hydrophobic signal. Processing of the potential signal peptide produces mature proteins that include an N-terminal region, a basic central domain with a high proportion of lysine residues as well as a proline-rich region that immediately precedes the C-terminal poly-cysteine domain. The expression of asip1 mRNA in the ventral area was significantly higher than in the dorsal region. Similarly, the expression of asip1 within the unpigmented patches in the dorsal skin of pseudoalbino fish was higher than in the pigmented dorsal regions but similar to those levels observed in the ventral skin. In addition, the injection/electroporation of asip1 capped mRNA in both species induced long term dorsal skin paling, suggesting the inhibition of the melanogenic pathways. The data suggest that fish asip1 is involved in the dorsal-ventral pigment patterning in adult fish, where it induces the regulatory asymmetry involved in precursor differentiation into mature chromatophore. Adult dorsal pseudoalbinism seems to be the consequence of the expression of normal developmental pathways in an inaccurate position that results in unbalanced asip1 production levels. This, in turn, generates a ventral-like differentiation environment in dorsal regions. © 2012 Guillot et al.

Maccari M.,University of Hull | Maccari M.,Institute Acuicultura Of Torre Of La Sal | Amat F.,Institute Acuicultura Of Torre Of La Sal | Gomez A.,University of Hull
PLoS ONE | Year: 2013

There is wide interest in understanding how genetic diversity is generated and maintained in parthenogenetic lineages, as it will help clarify the debate of the evolution and maintenance of sexual reproduction. There are three mechanisms that can be responsible for the generation of genetic diversity of parthenogenetic lineages: contagious parthenogenesis, repeated hybridization and microorganism infections (e.g. Wolbachia). Brine shrimps of the genus Artemia (Crustacea, Branchiopoda, Anostraca) are a good model system to investigate evolutionary transitions between reproductive systems as they include sexual species and lineages of obligate parthenogenetic populations of different ploidy level, which often co-occur. Diploid parthenogenetic lineages produce occasional fully functional rare males, interspecific hybridization is known to occur, but the mechanisms of origin of asexual lineages are not completely understood. Here we sequenced and analysed fragments of one mitochondrial and two nuclear genes from an extensive set of populations of diploid parthenogenetic Artemia and sexual species from Central and East Asia to investigate the evolutionary origin of diploid parthenogenetic Artemia, and geographic origin of the parental taxa. Our results indicate that there are at least two, possibly three independent and recent maternal origins of parthenogenetic lineages, related to A. urmiana and Artemia sp. from Kazakhstan, but that the nuclear genes are very closely related in all the sexual species and parthenogegetic lineages except for A. sinica , who presumable took no part on the origin of diploid parthenogenetic strains. Our data cannot rule out either hybridization between any of the very closely related Asiatic sexual species or rare events of contagious parthenogenesis via rare males as the contributing mechanisms to the generation of genetic diversity in diploid parthenogenetic Artemia lineages. © 2013 Maccari et al.

Palenzuela O.,Institute Acuicultura Of Torre Of La Sal | Alvarez-Pellitero P.,Institute Acuicultura Of Torre Of La Sal | Sitja-Bobadilla A.,Institute Acuicultura Of Torre Of La Sal
Applied and Environmental Microbiology | Year: 2010

Multilocus phylogenetic analysis of small-subunit (SSU) rRNA and actin from Cryptosporidium molnari clustered this species with the C. molnari-like genotype of an isolate from the guppy, although the two fish isolates seem to be distinct species. The analysis of available piscine genotypes provides some support for cladistic congruence of the genus Piscicryptosporidium, but additional piscine genotypes are needed. © 2010, American Society for Microbiology.

Leal E.,Institute Acuicultura Of Torre Of La Sal | Fernandez-Duran B.,Institute Acuicultura Of Torre Of La Sal | Agulleiro M.J.,Institute Acuicultura Of Torre Of La Sal | Conde-Siera M.,University of Vigo | And 2 more authors.
Hormones and Behavior | Year: 2013

Dopamine is synthesized from l-dopa and subsequently processed into norepinephrine and epinephrine. Any excess neurotransmitter can be taken up again by the neurons to be broken down enzymatically into DOPAC. The effect of dopamine on mammalian food intake is controversial. Mice unable to synthesize central dopamine die of starvation. However, studies have also shown that central injection of dopamine inhibits food intake. The effect of dopaminergic system in the fish feeding behavior has been scarcely explored. We report that the inclusion of l-dopa in the diets results in the activation of sea bass central dopaminergic system but also in the significant increase of the hypothalamic serotonin levels. Dietary l-dopa induces a decrease of food intake and feed conversion efficiency that drives a decline of all growth parameters tested. No behavioral effects were observed after l-dopa treatment. l-dopa treatment stimulated central expression of NPY and CRF. It suggests that CRF might mediate l-dopa effects on food intake but also that CRF neurons lie downstream of NPY neurons in the hierarchical forebrain system, thus controlling energy balance. Unexpectedly, dietary administration of haloperidol, a D2-receptor antagonist, cannot block dopamine effects but also induces a decline of the food intake. This decrease seems to be a side effect of haloperidol treatment since fish exhibited a decreased locomotor activity. We conclude that oral l-dopa inhibits sea bass food intake and growth. Mechanism could also involve an increase of hypothalamic serotoninergic tone. © 2013 Elsevier Inc.

Redondo M.J.,Institute Acuicultura Of Torre Of La Sal | Alvarez-Pellitero P.,Institute Acuicultura Of Torre Of La Sal
Experimental Parasitology | Year: 2010

The involvement of the lectin/carbohydrate interaction in the invasion of the turbot intestinal epithelium by Enteromyxum scophthalmi was studied in vitro using explants of turbot intestine and pre-treatment of parasite stages with the plant lectins of Canavalia ensiformis (Con A) and Glycine max (SBA). Both lectins inhibited the attachment and invasion of E. scophthalmi stages to the intestinal epithelium, though the inhibitory effect was higher for SBA than for Con A. Such results point to the involvement of N-acetyl-galactosamine (GalNAc) and galactose (Gal) residues and also of mannose/glucose residues in the E. scophthalmi-intestinal epithelium interaction. The inhibitory effect of both lectins on the parasite adhesion and penetration points to the interest of further studies to confirm the presence of putative lectins recognising GalNAc-Gal and mannose/glucose residues in turbot intestine. The obtained results demonstrated also the adequacy of turbot intestinal explants as an in vitro model to study the interaction with E. scophthalmi. © Elsevier Inc.

Redondo M.J.,Institute Acuicultura Of Torre Of La Sal | Alvarez-Pellitero P.,Institute Acuicultura Of Torre Of La Sal
Parasitology International | Year: 2010

The influence of Enteromyxum spp. infections on the carbohydrate patterns of the digestive tract of gilthead sea bream (GSB) Sparus aurata L. and turbot (TB) Psetta maxima (L.) has been studied. Histochemical stainings to differentiate the types of mucins and lectin-binding assays to detect terminal carbohydrate residues were applied to histological sections of GSB and TB uninfected or infected by Enteromyxum leei and E. scophthalmi, respectively. The number of intestinal GC decreased in severely infected fish in both parasitoses, though changes in mucin patterns were limited to the decrease in the staining intensity for acidic mucins in infected GSB. The TB stomach and intestine lacked histochemically detectable acidic mucins, or sialic acid detectable by SNA, in contrast with their abundance in GSB. Glucose/mannose, fucose and GlcNAc residues were less abundant in both infected hosts with respect to uninfected fish. In contrast, D-Gal and D-GalNAc moieties (detectable by BSL I) increased in most parts of E. scophthalmi-infected TB while decreasing (oesophagus) or remaining unchanged (intestine) in E. leei-infected GSB. The decreasing in the expression of acidic mucins and of sialic acid detectable by SNA in E. leei-infected GSB is remarkable. Differences in the carbohydrate patterns between both hosts could aid to explain the differences in the severity of both enteromyxoses. In addition, the changes induced by Enteromyxum spp. infections in the digestive tract of GSB and TB suggest a role of terminal carbohydrate residues in the parasite-host interaction. © 2010 Elsevier Ireland Ltd.

Sanchez E.,Institute Acuicultura Of Torre Of La Sal | Rubio V.C.,Institute Acuicultura Of Torre Of La Sal | Cerda-Reverter J.M.,Institute Acuicultura Of Torre Of La Sal
General and Comparative Endocrinology | Year: 2010

Melanocortin 1 receptor (MC1R) plays a key role in the physiology of the vertebrate pigment system. Point mutations producing hyperactive or inactive receptors result in darkening or paling effects, respectively. We report the molecular and pharmacological characterization, as well as the tissue expression pattern, of the sea bass Mc1r. Similar to other MC1Rs, the sea bass gene is highly polymorphic and nine DNA polymorphisms, seven of them involving an amino acid substitution, were detected. SbMc1r is mainly expressed in the testis, fat and liver with moderate levels in the ventral and dorsal skin. The sea bass receptor was activated by all the melanocortins tested, with ACTH showing the lowest efficiency. The acetylation level of the MSH isoforms seems to be critical for the effectively of the agonist. Agouti-related protein (AGRP) drastically inhibited the basal activity of the receptor in vitro, as an inverse agonist does, but only in the presence of phosphodiesterase inhibitors. This observation suggests that sbMc1r is constitutively activated and inversely regulated by AGRP, which is expressed in the skin of different fish species. © 2009 Elsevier Inc. All rights reserved.

Alvarado M.V.,Institute Acuicultura Of Torre Of La Sal | Carrillo M.,Institute Acuicultura Of Torre Of La Sal | Felip A.,Institute Acuicultura Of Torre Of La Sal
Comparative Biochemistry and Physiology -Part A : Molecular and Integrative Physiology | Year: 2015

Evidence exists that melatonin may drive the seasonal changes in kisspeptin-expressing cells and GnRH/gonadotropin secretion in mammals, thus modulating their reproductive activity. This study established the influence of long-term melatonin administration (as an implant) on growth performance and reproduction of adult male sea bass. Melatonin reduced the fish weight and condition factor, thus affecting the performance of fish. Melatonin also affected gonadogenesis, as shown by a decrease in the gonadosomatic index after 150. days of treatment (29% lower than in controls) and the lower percentage of running males between January and March during the spermatogenesis and full spermiation stages of this species. Exogenous melatonin also resulted in lower plasma androgen levels during the reproductive period, and showed a significant decrease in serum Lh and Fsh concentration after 30 and 60. days of treatment, respectively. These findings indicated that melatonin elicited seasonal changes in key reproductive hormones that affected testicular maturity. The hypothalamic expression of kiss1 was significantly higher in melatonin-treated fish than in controls after 30. days of treatment, while a significant increase in kiss2 expression was detected on day 90 of treatment. By contrast, melatonin showed a significant decrease in kisspeptin expression in the dorsal brain on day 150 of treatment and also affected the expression of gnrh-1 and gnrh-3 and gnrhr-II-1a and 2b and the fshβ gene in the pituitary. These results suggest that in this species, melatonin evokes changes in the mRNA levels of kisspeptin and gnrh system genes that appear to mirror disturbances in spermatogenesis. © 2015 Elsevier Inc.

Rubio V.C.,Institute Acuicultura Of Torre Of La Sal | Sanchez E.,Institute Acuicultura Of Torre Of La Sal | Cerda-Reverter J.M.,Institute Acuicultura Of Torre Of La Sal
Aquaculture | Year: 2010

This work was designed to study the re-feeding dynamics of sea bass (Dicentrarchus labrax) following food deprivation and food-intake reduction induced by physical stressors. Two experiments were carried out, using one hundred sea bass distributed into 10 tanks provided with self-feeders and kept under natural environmental conditions. The first experiment focused on the self-feeding behaviour after two short-term fasting periods (2 and 9 days). The second experiment examined the effects of three different stressors (human proximity, tank cleaning and sampling) on self-feeding behaviour. Food demands were registered every five minutes using on-demand self-feeders. The amount of food demanded but not consumed was registered on a daily basis, and daily food intake was calculated by difference. The effects on the re-feeding dynamics of the different experimental protocols were evaluated in winter and late spring. After two days of fasting, fish compensated by temporarily increasing the maximum daily feeding rate (51% and 53% during winter and late spring, respectively) without modifying their daily feeding activity. However, both the maximum intake (with a hyperphagic response of 79% and 210% during winter and late spring, respectively) and daily feeding activity were modified after more prolonged fasting (9 days). In this case, the daily feeding activity was lengthened compared with the pattern observed on pre-fasting days. The response was similar during winter and late spring, the only differences detected being related to the magnitude of the response. Feeding behaviour in the sea bass was very sensitive to the stress conditions. All the experimental stressors induced a modification in the food intake. Analysis of the daily feeding activity pointed to reduced demand-feeding activity for all the experimental protocols during the period when operators were working in the culture facilities. No differences were detected between the winter and late spring other than the magnitude of the response. Our results underline the sensitivity of the mechanisms controlling feeding behaviour to the routine physical stressors involved in the culture of the sea bass, as well as a differential re-feeding dynamics, depending on whether the fish were submitted to short (2 days) or long (9 days) fasting periods. The results point to the need to design suitable feeding strategies in response to the fasting and/or stress caused by routine human activities. These will differ according to the duration of the fasting and the season. © 2009 Elsevier B.V. All rights reserved.

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