scholarly journals Best therapeutic practices for the use of antibacterial agents in finfish aquaculture: a particular view on European seabass ( Dicentrarchus labrax ) and gilthead seabream ( Sparus aurata ) in Mediterranean aquaculture

2020 ◽  
Author(s):  
George Rigos ◽  
Dimitra Kogiannou ◽  
Francesc Padrós ◽  
Carles Cristòfol ◽  
Daniela Florio ◽  
...  
2020 ◽  
Author(s):  
C. Peñaloza ◽  
T. Manousaki ◽  
R. Franch ◽  
A. Tsakogiannis ◽  
A. Sonesson ◽  
...  

AbstractSNP arrays are powerful tools for high-resolution studies of the genetic basis of complex traits, facilitating both population genomic and selective breeding research. The European seabass (Dicentrarchus labrax) and the gilthead seabream (Sparus aurata) are the two most important fish species for Mediterranean aquaculture. While selective breeding programmes increasingly underpin stocky supply for this industry, genomic selection is not yet widespread. Genomic selection has major potential to expedite genetic gain, in particular for traits practically impossible to measure on selection candidates, such as disease resistance and fillet yield. The aim of our study was to design a combined-species 60K SNP array for both European seabass and gilthead seabream, and to validate its performance on farmed and wild populations from numerous locations throughout the species range. To achieve this, high coverage Illumina whole genome sequencing of pooled samples was performed for 24 populations of European seabass and 27 populations of gilthead seabream. This resulted in a database of ~20 million SNPs per species, which were then filtered to identify high-quality variants and create the final set for the development of the ‘MedFish’ SNP array. The array was then tested by genotyping a subset of the discovery populations and demonstrated a high conversion rate to functioning polymorphic assays on the array (92% in seabass: 89% in seabream) and repeatability (99.4 - 99.7%). The platform interrogates ~30K markers in each fish species, includes features such as SNPs previously shown to be associated with performance traits, and is enriched for SNPs predicted to alter protein function. The array was demonstrated to be effective at detecting population structure across a wide range of fish populations from diverse geographical origins, and to examine the extent of haplotype sharing among Mediterranean fish farms. Therefore, the MedFish array enables efficient and accurate high-throughput genotyping for genome-wide distributed SNPs on each fish species, and will facilitate stock management, population genomics approaches, and acceleration of selective breeding through genomic selection.


2016 ◽  
Vol 60 (2) ◽  
Author(s):  
M. Úbeda-Manzanaro ◽  
J.B. Ortiz-Delgado ◽  
C. Sarasquete

<p>Multiple genes and transcription factors are involved in regulation and control of the complex process of sex determination and differentiation of fish species. Also more, several hormonal factors and some environmental conditions can also be adequate spawning strategies and stimuli for inducing reproduction of fish species. <em>Brdt</em> gene belongs to the bromodomain-extraterminal domain (BET) family of transcriptional coregulators. In mammals, <em>Brdt</em> gene is almost exclusively expressed in testis. Furthermore, Brdt protein is involved in elongating spermatids, and is required for proper spermatogenesis and male fertility. However, from our understanding of fish species, the role of this gene as key, during gametogenesis, still remains unknown. In this study, two <em>Brdt</em> mRNA transcripts were isolated from two teleostean fish species, gilthead seabream and European seabass. In both species the shorter form lacked a functional C-terminal domain, which may involve a different function as transcriptional regulator. The pattern of <em>Brdt</em> expression showed that the highest levels occurred in the gonads. Significantly lower levels of expression were detected in brain, pituitary and different organ systems (heart, kidney, gills, among other somatic tissues) from both studied species. <em>In situ</em> hybridization approach evidenced that <em>Brdt</em> mRNA expression was restricted to specific cell-types of the germ line, during both oogenesis and spermatogenesis processes.</p>


2002 ◽  
Vol 87 (5) ◽  
pp. 459-469 ◽  
Author(s):  
V. Fournier ◽  
M. F. Gouillou-Coustans ◽  
R. Métailler ◽  
C. Vachot ◽  
M. J. Guedes ◽  
...  

Besides being an indispensable amino acid for protein synthesis, arginine (Arg) is also involved in a number of other physiological functions. Available data on the quantitative requirement for Arg in different teleosts appear to show much variability. So far, there are very limited data on the maintenance requirements of indispensable amino acids (IAA) in fish. In the present study, we compared N and Arg requirements for maintenance and growth of four finfish species: rainbow trout (Oncorhynchus mykiss), turbot (Psetta maxima), gilthead seabream (Sparus aurata) and European seabass (Dicentrarchus labrax). Groups of fish having an initial body weight close to 5–7 g were fed semi-purified diets containing graded levels of N (0 to 8 % DM) and Arg (0 to 3 % DM) over 4 to 6 weeks. For each species, N and Arg requirements for maintenance and for growth were calculated regressing daily N gain against daily N or Arg intakes. N requirement for maintenance was estimated to be 37·8, 127·3, 84·7 and 45·1 mg/kg metabolic body weight per d and 2·3, 2·2, 2·6 and 2·5 g for 1 g N accretion, in rainbow trout, turbot, gilthead seabream and European seabass respectively. The four species studied appear to have very low or no dietary Arg requirements for maintenance. Arg requirement for g N accretion was calculated to be 0·86 g in rainbow trout and between 1·04–1·11 g in the three marine species. Turbot required more N for maintenance than the other three species, possibly explaining its reputedly high overall dietary protein requirement. Data suggest a small but sufficient endogenous Arg synthesis to maintain whole body N balance and differences between freshwater and marine species as regards Arg requirement. It is worth verifying this tendency with other IAA.


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