Determinants biològics i fisiològics del Pagre (Pagrus pagrus). Punts claus per al seu cultiu intensiu

The sparid teleost red porgy (PagntS pagn¡s) is an species with increasing potential and interest in the commercial aquaculture of the Mediterranean area. Although many of the aspects concerning its reproduction and nutrition are not well known, spontaneous spawning has been obtained in fish farms and growth rates obtained with commercial food are similar to those of sea bass and sea bream. Concerning culture conditions and stress influences, the results seem to suggest that red porgy shows a lower degree of adaptation compared to other Mediterranean sparids

Peixos transgènics

La generació d'organismes modificats genèticament (OMG) ha representat un avanç tecnològic molt important en totes les àrees de recerca biològica. Així, la producció d'animals transgènics ha estat una eina molt valuosa per a l'establiment d'organismes model en recerca biomèdica, la producció massiva de macromolècules biològicament actives i el desenvolupament de cultius d'aliments, entre d'altres. Malgrat que tradicionalment els mamífers han estat els vertebrats més emprats per a la generació d'animals transgènics, els peixos constitueixen una alternativa excel·lent. Comparats amb els mamífers, els peixos presenten tot un conjunt de característiques, tant evolutives com fisiològiques, i també una sèrie d'interessos comercials i tecnològics, que estan fent d'aquests organismes els animals amb més potencial en els diferents camps d'aplicació de la tecnologia de manipulació genètica. En aquesta revisió, a més de presentar els darrers avenços tecnològics disponibles per a la generació de peixos transgènics, es repassen les diferents aplicacions de la transferència gènica en peixos, i també els beneficis i els possibles riscos derivats d'aquest ús. Paraules clau: peix, transgènesi, vector, tècniques de transferència gènica, aqüicultura,The generation of genetically modified organisms (GMOs) has provided an important technological advance to many areas of biological research. The production of these GMOs has been a valuable tool for the establishment of model organisms for biomedical research and the commercial production of biologically active macromolecules and food, amongst others. Traditionally, mammals have been used as the model organisms however in recent years the production of transgenic fish has provided an excellent alternative. Compared with mammals, fish presents some ideal physiological characteristics and evolutionary features, which together with recent technological advances and commercial interests, make fish an ideal candidate for genetic manipulation. This paper provides a brief summary of the most recent relevant data in this field

Diferències morfomètriques i merístiques entre l'orada cultivada i salvatge

Gilthead seabream is of high commercíal interest and has become an important aquacultural resource in the Mediterranean countries. Now, the aim of improving the quality of reared products in order to meet markets preferences of conformity with wild standards is a new priority, The aim of this study is the use of morphometrics and meristics for the quantification of the differences in quality assessment and on their causative factors between and within sea bream reared in different fish farms and wild standards. Reared S.auratus show higher body depth, caudal peduncle depth, last dorsal spine, anal fin rays number and position of first anal spine respect to dorsal, and lower head depth, snout length, preorbital length, predorsal length, dorsal fin base, pectoral fin length, ventral fin length, caudal peduncle length, scales berween lateral line and dorsal, pectoral fin rays number and largest dorsal fin spine than wild sea bream. Apart of this measures, Cupimar hatchery facility has fish with lower head length, interorbital length and distance between pelvic and pectoral fins than wild sea bream; Maresa hatchery físhes have lower anal fin base and higher head length than wild standards, Blanes Peix sea cages show lower head length, orbital diameter and interorbital length than wild standards; and Aquadelt fishes show lower head length, orbital diameter, interorbital length, distance berween pelvic and pectoral fins and preanal length than wild sea bream and a non significant difference in last dorsal spine

Loss-of-function mutations in the melanocortin 1 receptor cause disruption of dorso-ventral countershading in teleost fish

13 pages, 8 figuresThe melanocortin 1 receptor (MC1R) is the central melanocortin receptor involved in vertebrate pigmentation. Mutations in this gene cause variations in coat coloration in amniotes. Additionally, in mammals MC1R is the main receptor for agouti‐signaling protein (ASIP), making it the critical receptor for the establishment of dorsal‐ventral countershading. In fish, Mc1r is also involved in pigmentation, but it has been almost exclusively studied in relation to melanosome dispersion activity and as a putative genetic factor involved in dark/light adaptation. However, its role as the crucial component for the Asip1‐dependent control of dorsal‐ventral pigmentation remains unexplored. Using CRISPR/Cas9, we created mc1r homozygous knockout zebrafish and found that loss‐of‐function of mc1r causes a reduction of countershading and a general paling of the animals. We find ectopic development of melanophores and xanthophores, accompanied by a decrease in iridophore numbers in the ventral region of mc1r mutants. We also reveal subtle differences in the role of mc1r in repressing pigment cell development between the skin and scale niches in ventral regionsThis work was funded by the Spanish Economy and Competitiveness Ministry projects AGL2011‐23581, AGL2014‐52473R, AGL2017‐89648P to JR. Partial funding was obtained from AGL2016‐74857‐C3‐3‐R to JMCR. L. Cal was supported by predoctoral fellowship FPI funded by Spanish Economy and Competitiveness Ministry (AGL2011‐23581) and by predoctoral fellowship of the Spanish Personnel Research Training Program funded by Spanish Economy and Competitiveness Ministry (EEBB‐C‐14‐00467). P Suarez‐Bregua was supported by AGL2014‐52473R and AGL2017‐89648P project contractPeer reviewe

Expression and role of Elovl4 elongases in biosynthesis of very long-chain fatty acids during zebrafish Danio rerio early embryonic development

Elovl4 is a fatty acyl elongase that participates in the biosynthesis of very long-chain fatty acids (≥C24), which are relatively abundant in skin (saturated chains), or retina, brain and testes (polyunsaturated chains) of mammals. In the present study we characterised two Elovl4 proteins, Elovl4a and Elovl4b, from zebrafish Danio rerio, and investigated their expression patterns during embryonic development. Heterologous expression in baker’s yeast showed that both zebrafish Elovl4 proteins efficiently elongated saturated fatty acids up to C36, with 26:0 appearing the preferred substrate as reported for human ELOVL4. Interestingly, activity for the elongation of PUFA substrates was only shown by Elovl4b, which effectively converted eicosapentaenoic (20:5n-3) and arachidonic (20:4n-6) acids to elongated polyenoic products up to C36. Furthermore, zebrafish Elovl4b may be involved in the biosynthesis of docosahexaenoic acid (22:6n-3, DHA) as it had the capacity to elongate 22:5n-3 to 24:5n-3 which can be subsequently desaturated and chain shortened to DHA in peroxisomes. The distinct functional roles of zebrafish Elovl4 proteins were also reflected in their spatial-temporal expression patterns during ontogeny. Analyses by whole-mount in situ hybridisation in zebrafish embryos showed that elovl4a was expressed in neuronal tissues (wide-spread distribution in the head area), with elovl4b specifically expressed in epiphysis (pineal gland) and photoreceptor cells in the retina. Similarly, tissue distribution in adults revealed that elovl4a transcripts were found in most tissues analysed, whereas elovl4b expression was essentially restricted to eye and gonads. Overall, the results suggest that zebrafish elovl4b resembles other mammalian orthologues in terms of function and expression patterns, whereas elovl4a may represent an alternative elongase not previously described in vertebrates

Pth reloaded: a new evolutionary perspective

The parathyroid hormone (PTH) family is a group of structurally-related secreted peptides involved in bone mineral homeostasis and multitude of developmental processes in vertebrates. These peptides mediate actions through PTH receptors (PTHRs), which belong to the transmembrane G protein-coupled receptor group. To date, genes encoding for PTH and PTHR have only been identified in chordates, suggesting that this signaling pathway may be an evolutionary innovation of our phylum. In vertebrates, we found up to six PTH and three PTHR different paralogs, varying in number between mammals and teleost fishes due to the different rounds of whole-genome duplication and specific gene losses suffered between the two groups of animals. The diversification of the PTH gene family has been accompanied by both functional divergence and convergence, making sometimes difficult the comparison between PTH peptides of teleosts and mammals. Here, we review the roles of all Pth peptides in fishes, and based on the evolutionary history of PTH paralogs, we propose a new and simple nomenclature from PTH1 to PTH4. Moreover, the recent characterization of the Pth4 in zebrafish allows us to consider the prominent role of the brain-to-bone signaling pathway in the regulation of bone development and homeostasis. Finally, comparison between PTH peptides of fish and mammals allows us to discuss an evolutionary model for PTH functions related to bone mineral balance during the vertebrate transition from an aquatic to a terrestrial environment

Role of the Melanocortin System in Gonadal Steroidogenesis of Zebrafish

In teleost, as in other vertebrates, stress affects reproduction. A key component of the stress response is the pituitary secretion of the adrenocorticotropic hormone (ACTH), which binds to the melanocortin 2 receptor (MC2R) in the adrenal glands and activates cortisol biosynthesis. In zebrafish, Mc2r was identified in male and female gonads, while ACTH has been shown to have a physiological role in modulating reproductive activity. In this study, the hypothesis that other melanocortins may also affect how the zebrafish gonadal function is explored, specifically steroid biosynthesis, given the presence of members of the melanocortin signaling system in zebrafish gonads. Using cell culture, expression analysis, and cellular localization of gene expression, our new observations demonstrated that melanocortin receptors, accessory proteins, antagonists, and agonists are expressed in both the ovary and testis of zebrafish (n = 4 each sex). Moreover, melanocortin peptides modulate both basal and gonadotropin-stimulated steroid release from zebrafish gonads (n = 15 for males and n = 50 for females). In situ hybridization in ovaries (n = 3) of zebrafish showed mc1r and mc4r in follicular cells and adjacent to cortical alveoli in the ooplasm of previtellogenic and vitellogenic oocytes. In zebrafish testes (n = 3), mc4r and mc1r were detected exclusively in germ cells, specifically in spermatogonia and spermatocytes. Our results suggest that melanocortins are, directly or indirectly, involved in the endocrine control of vitellogenesis in females, through modulation of estradiol synthesis via autocrine or paracrine actions in zebrafish ovaries. Adult zebrafish testes were sensitive to low doses of ACTH, eliciting testosterone production, which indicates a potential role of this peptide as a paracrine regulator of testicular function.publishedVersio

Functional analysis of new human Bardet-Biedl syndrome loci specific variants in the zebrafish model

The multiple genetic approaches available for molecular diagnosis of human diseases have made possible to identify an increasing number of pathogenic genetic changes, particularly with the advent of next generation sequencing (NGS) technologies. However, the main challenge lies in the interpretation of their functional impact, which has resulted in the widespread use of animal models. We describe here the functional modelling of seven BBS loci variants, most of them novel, in zebrafish embryos to validate their in silico prediction of pathogenicity. We show that target knockdown (KD) of known BBS (BBS1, BB5 or BBS6) loci leads to developmental defects commonly associated with ciliopathies, as previously described. These KD pleiotropic phenotypes were rescued by co-injecting human wild type (WT) loci sequence but not with the equivalent mutated mRNAs, providing evidence of the pathogenic effect of these BBS changes. Furthermore, direct assessment of cilia located in Kupffer’s vesicle (KV) showed a reduction of ciliary length associated with all the studied variants, thus confirming a deleterious effect. Taken together, our results seem to prove the pathogenicity of the already classified and unclassified new BBS variants, as well as highlight the usefulness of zebrafish as an animal model for in vivo assays in human ciliopathiesMinisterio de Economía y Competitividad | Ref. AGL2017-89648

Environmental DNA (eDNA) for monitoring marine mammals: Challenges and opportunities

Monitoring marine mammal populations is essential to permit assessment of population status as required by both national and international legislation. Traditional monitoring methods often rely on visual and/or acoustic detections from vessels and aircraft, but limitations including cost, errors in the detection of some species and dependence on taxonomic expertise, as well as good weather and visibility conditions often limit the temporal and spatial scale of effective, long-term monitoring programs. In recent years, environmental DNA (eDNA) has emerged as a revolutionary tool for cost-effective, sensitive, noninvasive species monitoring in both terrestrial and aquatic realms. eDNA is a rapidly developing field and a growing number of studies have successfully implemented this approach for the detection and identification of marine mammals. Here, we review 21 studies published between 2012 and 2021 that employed eDNA for marine mammal monitoring including single species detection, biodiversity assessment and genetic characterization. eDNA has successfully been used to infer species presence (especially useful for rare, elusive or threatened species) and to characterize the population genetic structure, although additional research is needed to support the interpretation of non-detections. Finally, we discuss the challenges and the opportunities that eDNA could bring to marine mammal monitoring as a complementary tool to support visual and acoustic methods

Agouti overexpression in a transgenic model regulates integrity, permeability and electrogenic amino acid transport in zebrafish intestine

Overexpression of asip1 in transgenic zebrafish disrupts dorsoventral pigment pattern in addition to increasing food intake levels and linear growth. A higher feed intake is unnecessary in transgenic fish to enable larger and heavier growth. A plausible explanation may rely on the enhanced feeding efficiency mediated by improved nutrient absorption in transgenic animals. To test this hypothesis, wide scope transcriptomic techniques were used to elucidate the potential pathways involved in the enhanced nutrient absorption and intestinal epithelium permeability/integrity. In addition, the electrogenic capacity for amino acid transport was analysed. Transcriptomic analysis reveal that amino acid, monocarboxylates, ionic and vitamin transmembrane transporters were substantially modified. Enrichment analysis also revealed an inhibition of intestinal lipid metabolism and down-regulation of KEGG pathways related to membrane integrity suggesting augmented intestinal laxity that may enhance paracellular transport. Electrophysiological experiments carried out in Ussing chambers show that asip1 overexpression decrease membraned tissue resistance (Rt), indicating a modification of the intestinal barrier function in ASIP1 transgenic animals. Similarly, paracellular permeability was higher in transgenic zebrafish. Both the decrease in Rt and the increase in permeability point to an ASIP1-dependent decrease in the tissue barrier function. Electrogenic amino acid transport was also enhanced in transgenic animals providing strong indication that ASIP1 fish can extract more amino acids from their diet at similar feeding levels. Both transcriptomic and electrophysiological results suggest that asip1-overexpressing zebrafish display improved nutrient absorption and by extension a higher feed efficiency which explains enhanced growth in the absence of augmented food intake. The enhanced growth of ASIP1 zebrafish potentially mediated by improved nutrient uptake and feed efficiency suggests that the melanocortin system, specifically asip1 overexpression, is a potential target for the development of genetically engineered fish displaying improved performance and no differential lipid accumulation.info:eu-repo/semantics/publishedVersio