J.M. Afonso

Universidad de Las Palmas de Gran Canaria, Las Palmas, Canary Islands, Spain

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Publications (9)18.95 Total impact

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    ABSTRACT: Morphological abnormalities, especially skeletal deformities, are some of the most important problems affecting gilthead seabream (Sparus aurata L.) aquaculture industry. In this study, a QTL analysis for LSK complex deformity in gilthead seabream is reported. LSK complex is a severe deformity consisting of a consecutive repetition of three vertebral deformities: lordosis, scoliosis, and kyphosis. Seventy-eight offspring from six breeders from a mass-spawning were analyzed: five full-sibling families, three maternal, and two paternal half-sibling families. They had shown a significant association with the LSK complex prevalence in a previous segregation analysis. Fish were genotyped using a set of multiplex PCRs (ReMsa1-13), which includes 106 microsatellite markers. Two methods were used to perform the QTL analysis: a linear regression with the GridQTL software and a linear mixed model with the Qxpak software. A total of 18 QTL were identified. Four of them (QTLSK3, 6, 12, and 14), located in LG5, 8, 17, and 20, respectively, were the most solid ones. These QTL were significant at genome level and showed an extremely large effect (>35 %) with both methods. Markers close to the identified QTL showed a strong association with phenotype. Two of these molecular markers (DId-03-T and Bt-14-F) were considered as potential linked-to-this-deformity markers. The detection of these QTL supposes a critical step in the implementation of marker-assisted selection in this species, which could decrease the incidence of this deformity and other related deformities. The identification of these QTL also represents a major step towards the study of the etiology of skeletal deformities in this species.
    No preview · Article · Oct 2015 · Marine Biotechnology
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    ABSTRACT: Carcass quality traits such as visceral fat and fish morphology have a direct influence on final product and consumer preferences, especially in species as sea breamthat are sold as whole fish. Nevertheless, strategies that involve the development of selection schemes for these traits of economic interest in gilthead sea bream are limited. In this study the effect of the origin of the broodstock on carcass quality traits was analyzed in harvest size (690 days post-hatching) gilthead sea bream for the first time. For this purpose, a population (n= 890) of farmed gilthead sea breamobtained by industrial mass-spawnings frombroodstocks from three different origins [Cantabrian Sea (CAN), the Atlantic Ocean (ATL) and Mediterranean Sea (MED)] was analyzed for condition factor, visceral fat content, dressing weight, dressing percentage, fillet weight and fillet percentage.Moreover, with the goal of estimating genetic parameters (heritabilities and genetic correlations) for carcass quality traits aswell as their correlations with growth (harvest weight and length), a reconstruction of pedigree was carried out a posteriori. The origin had an effect on several carcass traits. Fish fromATL showed the lowest visceral fat percentage, dressing weight and percentage and those form CAN the lowest condition factor. These differences among origins can be explained through their different genetic backgrounds but also by environmental conditions in the initial facilities, where each origin was reared, and the derivate genotype × environment interactions. All carcass traits showedmediumheritabilities (ranging from0.17 to 0.24) andwere estimated with accuracy (standard errors from 0.05 to 0.07) except dressing (0.07 ± 0.05) and fillet (0.11 ± 0.05) percentage. Due to their genetic correlations, selection on weight could lead to an increase in condition factor (0.47±0.21) but, at the same, to an undesirable increase in visceral fat (0.42±0.20) and a decrease in fillet yield (−0.58±0.09).However, selection on length could improve dressing (0.87±0.07) and filletweight (0.84±0.09). Alternatively, visceral fat content could be decreased by selection through condition factor (−0.46 ± 0.16). All findings reported in this study should be relevant for the establishment of successful breeding programs in aquaculture of this species.
    No preview · Article · Sep 2015 · Aquaculture
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    ABSTRACT: Growth rates and the presence of deformities can be affected by the use of different rearing systems as well as by the different genetic origins of the stocks. At the same time, strategies that involve the development of selection schemes for these traits of economic interest are scarce. In this study the effect of the origin of the broodstock on growth traits and external deformities as well as genetic parameters (heritabilities and genetic correlations) for these traits were estimated at different ages (days post-hatching; dph). For this purpose, a population of farmed gilthead sea bream was obtained from three broodstock of different origins along the Spanish coasts [Cantabrian Sea (CAN), the Atlantic Ocean (ATL) and Mediterranean Sea (MED)] and reared under the same intensive conditions. Parental assignments between breeders and their offspring were carried out a posteriori using a microsatellite multiplex (SMsa1). Juveniles from MED showed the fastest growth while those from ATL showed the slowest growth and the highest incidence of vertebral column deformities. Differences among origins could be explained not only through their different genetic backgrounds but also by environmental conditions in the initial facilities, where different origins were reared separately, and by genotype × environment interactions. Growth traits showed low heritabilities at 163 dph (0.11 ± 0.03) and medium at 690 dph (0.25 ± 0.06 for weight; 0.22 ± 0.07 for length) suggesting that selection at the later age would be more appropriate. Both traits were highly and positively correlated at both ages at the genetic and phenotypic levels. External deformities in the vertebral column as well as in the operculum showed medium–high heritability at both studied ages with higher values at 690 dph (0.56 [0.17–0.69] and 0.46 [0.20–0.90], respectively). These results revealed that the ontogenesis of deformities exhibits a partial genetic basis. Nevertheless, for those in the rest of the head the heritability was close to zero. Initially, positive genetic correlations between growth and deformities in the vertebral column were observed (83% probability of being positive for weight-vertebral column deformity; 81% for length-vertebral column deformity). However, these correlations seem to be negative at 690 dph (94.2% probability of being negative for weight-vertebral column; 80.6% for length-vertebral column). Results confirm that it could be recommended to eliminate deformed fish from a breeding nucleus and later, select on growth. All these findings should be relevant for the establishment of successful breeding programs in the aquaculture of this species.
    Full-text · Article · Aug 2015 · Aquaculture
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    ABSTRACT: The complete removal of fishmeal (FM) and fish oil (FO) is required to promote the sustainable development of aquaculture and for that, fast growing high quality fish that are fed without FM and FO are necessary. Early nutritional programming may allow the production of fish better adapted to utilize diets with vegetable meals (VM) and oils (VO). The main objective of this study was to research in the potential value of fatty acids as modulators of early nutritional programming in marine fish for a better utilisation of VO/VM. For that purpose gilthead sea bream (Sparus aurata) broodstock were fed four different replacement levels of FO by linseed oil (LO) and their effect on fecundity and spawn quality, egg composition, Δ-6-desaturase (Δ6D) gene expression, progeny growth performance and their growth response to a challenge with diets low in FO and FM, but high in VO and VM. The results showed that feeding gilthead sea bream broodstock with high LO diets had very long-term effects on the progeny. Thus, FO replacement by LO up to 80-100% in broodstock diets for gilthead sea bream not only reduced fecundity and spawn quality, but also growth of 45 dah and 4-month-old juveniles, as well as Δ6D gene expression. However, when the 4 month-old juveniles were fed with a low FM and FO diet, even those from broodstock fed only 60% replacement of FO by LO showed a higher growth and feed utilization than juveniles from parents fed FO. These results demonstrate the interesting potential of early nutritional programming of marine fish by broodstock feeding to improve long-term performance of the progeny. Further studies are being conducted to determine optimum nutrient levels in the broodstock diets and the molecular mechanisms implied to develop effective nutritional intervention strategies for this species.
    Full-text · Article · Apr 2015 · Aquaculture
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    ABSTRACT: One of the most important problems of fish aquaculture is the high incidence of fish deformities, which are mainly skeletal. In this study, genetic parameters on gilthead seabream (Sparus aurata L.) for skeleton deformities at different ages (179, 269, 389, 539 and 689 days) and their correlations with growth traits were estimated, as were as their genotype × environment interactions (G × E) at harvesting age. A total of 4093 offspring from the mass spawning of three industrial broodstocks belonging to the PROGENSA(®) breeding programme were mixed and on-grown by different production systems in four Spanish regions: Canary Islands (tanks and cage), Andalusia (estuary), Catalonia (cage) and Murcia (cage). Parental assignment was inferred using the standardized SMsa1 microsatellite multiplex PCR. From three broodstocks, 139 breeders contributed to the spawn and a total of 297 full-sibling families (52 paternal and 53 maternal half-sibling families) were represented. Heritabilities at different ages were medium for growth traits (0.16-0.48) and vertebral deformities (0.16-0.41), and low for any type of deformity (0.07-0.26), head deformities (0.00-0.05) and lack of operculum (0.06-0.11). The genetic correlations between growth and deformity traits were medium and positive, suggesting that to avoid increasing deformities they should be taken into account in breeding programmes when growth is selected. The G × E interactions among the different facilities were weak for length and deformity and strong for growth rate during this period. These results highlight the potential for the gilthead seabream industry to reduce the prevalence of deformities by genetic improvement tools. © 2015 Stichting International Foundation for Animal Genetics.
    Full-text · Article · Feb 2015 · Animal Genetics
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    ABSTRACT: Growth rates and the presence of deformities can be affected by the use of different rearing systems aswell as by the different genetic origins of the stocks. At the same time, strategies that involve the development of selection schemes for these traits of economic interest are scarce. In this study the effect of the origin of the broodstock on growth traits and external deformities as well as genetic parameters (heritabilities and genetic correlations) for these traits were estimated at different ages (days post-hatching; dph). For this purpose, a population of farmed gilthead sea breamwas obtained fromthree broodstock of different origins along the Spanish coasts [Cantabrian Sea (CAN), the Atlantic Ocean (ATL) and Mediterranean Sea (MED)] and reared under the same intensive conditions. Parental assignments between breeders and their offspring were carried out a posteriori using a microsatellite multiplex (SMsa1). Juveniles from MED showed the fastest growth while those from ATL showed the slowest growth and the highest incidence of vertebral column deformities. Differences among origins could be explained not only through their different genetic backgrounds but also by environmental conditions in the initial facilities, where different origins were reared separately, and by genotype × environment interactions. Growth traits showed low heritabilities at 163 dph (0.11 ± 0.03) and medium at 690 dph (0.25 ± 0.06 for weight; 0.22± 0.07 for length) suggesting that selection at the later age would be more appropriate. Both traits were highly and positively correlated at both ages at the genetic and phenotypic levels. External deformities in the vertebral column as well as in the operculum showed medium–high heritability at both studied ages with higher values at 690 dph (0.56 [0.17–0.69] and 0.46 [0.20–0.90], respectively). These results revealed that the ontogenesis of deformities exhibits a partial genetic basis. Nevertheless, for those in the rest of the head the heritability was close to zero. Initially, positive genetic correlations between growth and deformities in the vertebral column were observed (83% probability of being positive for weight-vertebral column deformity; 81% for length-vertebral column deformity). However, these correlations seem to be negative at 690 dph (94.2% probability of being negative for weight-vertebral column; 80.6% for length-vertebral column). Results confirm that it could be recommended to eliminate deformed fish froma breeding nucleus and later, select on growth. All these findings should be relevant for the establishment of successful breeding programs in the aquaculture of this species.
    No preview · Article · Jan 2015 · Aquaculture
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    ABSTRACT: The high number of multiplex PCRs developed for gilthead seabream (Sparus aurata L.) from many different microsatellite markers does not allow comparison among populations. This highlights the need for developing a reproducible panel of markers, which can be used with safety and reliability by all users. In this study, the first standardised panel of two new microsatellite multiplex PCRs was developed for this species. Primers of 138 specific microsatellites from the genetic linkage map were redesigned and evaluated according to their genetic variability, allele size range and genotyping reliability. A protocol to identify and classify genotyping errors or potential errors was proposed to assess the reliability of each marker. Two new multiplex PCRs from the best assessed markers were designed with 11 markers in each, named SMsa1 and SMsa2 (SuperMultiplex Sparus aurata). Three broodstocks (59, 47 and 98 breeders) from different Spanish companies, and a sample of 80 offspring from each one, were analysed to validate the usefulness of these multiplexes in the parental assignation. It was possible to assign each offspring to a single parent pair (100% success) using the exclusion method with SMsa1 and/or SMsa2. In each genotyped a reference sample (Ref-sa) was used, and its DNA is available on request similar to the kits of bin set to genotype by genemapper (v.3.7) software (kit-SMsa1 and kit-SMsa2). This will be a robust and effective tool for pedigree analysis or characterisation of populations and will be proposed as an international panel for this species.
    Full-text · Article · Apr 2013 · Animal Genetics
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    ABSTRACT: This study reports two new and highly informative multiplex PCRs of microsatellite markers, with redesigned interspecific primer sets for three sparid species: gilthead seabream (Sparus auratus L.), red porgy (Pagrus pagrus L.) and redbanded seabream (P. auriga, Valenciennes, 1843). The evaluation and validation of the two multiplex PCRs, named RimA and RimB (Redesigned Interspecific Multiplex), were carried out upon: 148 individual gilthead seabream (66 breeders of unknown gender, and 82 of their descendents obtained by mass-spawning), 37 red porgy and 125 redbanded seabream. From 15 and 12 redesigned microsatellite markers for RimA and RimB, respectively, the number of markers included in the final multiplex PCRs were 10 in RimA and 7 in RimB for gilthead seabream, 6 in each multiplex PCR for red porgy and 8 in RimA and 5 in RimB for redbanded seabream. The a priori combined parental exclusion probability for each multiplex in the three species was 0.999. For gilthead seabream, it was possible to assign each offspring to a single parent pair (100% success) using the exclusion method with at least seven microsatellite markers for each multiplex PCR. Null alleles were found only for marker PbMS2, through familial segregation, with a frequency similar to the expected one (0.09 vs 0.14). Results revealed that the multiplex reaction no more than one-sixth the cost of single reactions even when these reactions were performed in a unique run, and that genotyping errors were minimized due to automation. These robust multiplex PCRs will be a fundamental tool for the industry to introduce selection programs and to manage their broodstocks under industrial conditions.
    No preview · Article · Dec 2008 · Aquaculture

  • No preview · Conference Paper · Jun 2005