RESUMEN
A produção aquícola mundial tem demandado estudos que buscam soluções para os problemas produtivos e sanitários apresentados na piscicultura. Nesse contexto, o uso de produtos probióticos demonstra ser uma abordagem promissora. Dessa forma, o presente trabalho teve como objetivo avaliar a viabilidade de um pool de cepas de Lactobacillus incorporados à ração de truta-arco-íris. Para tanto, as respectivas cepas foram previamente cultivadas em caldo MRS e submetidas à criocentrifugação. As células obtidas foram ressuspensas em soro fisiológico acrescentado de 2% de óleo de soja, sendo posteriormente incorporadas à ração por meio de misturador circular. Essa ração foi devidamente armazenada sob refrigeração a 4°C, por 120 dias, sendo retiradas aleatoriamente três amostras, a cada 15 dias, para avaliação da viabilidade das bactérias, por meio da contagem em placas. Os resultados demonstraram que houve uma redução não significativa (P>0,05) na população de células viáveis, correspondente a 2%, após 30 dias de armazenamento. Verificou-se também, após esse período, uma população aproximada equivalente a 3,00 x 108 UFC/g. Dessa forma, demonstrou-se a possibilidade de desenvolvimento de formulações probióticas por meio da incorporação de cepas específicas em rações de trutas, o que poderá contribuir para o desenvolvimento de tecnologias alternativas para produção de peixes.(AU)
Among the exotic species of fish produced in Brazil, the rainbow trout (Oncorhynchus mykiss) has been highlighted during the past few years. The expansion of this sector has been intensifying the need for further studies in order to decrease production and health problems presented in aquaculture, as well as to develop alternative technics to controversial antimicrobial treatments. In this context, the use of probiotics has been shown to be a promising approach to the improvement in trout husbandry. Thus, the present study aimed to contribute to the development of an alternative technology in the rainbow trout husbandry by evaluating the effect of probiotic preparations on the performance of the animals subjected to conventional husbandry conditions or chronic stress. Therefore, in this paper we report the results regarding the evaluation of the viability of a pool of 4 Lactobacillus probiotic strains incorporated into rainbow trout ration using soybean oil as vehicle. The results have demonstrated a high efficacy of cell incorporation into the ration with high viability rate after storage for 120 days at 4°C.(AU)
Asunto(s)
Animales , Oncorhynchus mykiss/crecimiento & desarrollo , Probióticos/administración & dosificación , Lactobacillus , Alimentación Animal/análisisRESUMEN
Length growth as a function of time has a non-linear relationship, so nonlinear equations are recommended to represent this kind of curve. We used six nonlinear models to calculate the length gain of rainbow trout (Oncorhynchus mykiss) during the final grow-out phase of 98 days under three different feed types in triplicate groups. We fitted the von Bertalanffy, Gompertz, Logistic, Brody, Power Function, and Exponential equations to individual length-at-age data of 900 fish. Equations were fitted to the data based on the least square method using the Marquardt iterative algorithm. Accuracy of the fitted models was evaluated using a model performance metrics combining mean squared residuals (MSR), mean absolute error (MAE) and Akaike's Information Criterion corrected for small sample sizes (AICc). All models converged in all cases tested. Evaluation criteria for the Logistic model indicated the best overall fit (0.67 of combined metric MSR, MAE and AICc) under all different feeding types, followed by the Exponential model (0.185), and the von Bertalanffy and Brody model (0.074, respectively). Additionally, ∆AICc results identify the Logistic and Gompertz models as being substantially supported by the data in 100% of cases. The logistic model can be suggested for length growth prediction in aquaculture of rainbow trout.(AU)
O crescimento em comprimento em função do tempo tem uma relação não linear; por isso, funções não lineares são recomendáveis para descrever essa relação. Seis modelos não lineares foram usados para calcular o ganho em comprimento de truta-arco-íris (Oncorhynchus mykiss) durante 98 dias, na fase final da engorda, submetidas a três dietas diferentes em grupos triplicados. Foram ajustadas as equações de von Bertalanffy, Gompertz, logístico, Brody, função potencial e exponencial a dados individuais de comprimento-idade de 900 peixes. O ajuste foi feito pelo método dos mínimos quadrados, usando-se o algoritmo iterativo de Marquardt. A precisão do ajuste foi avaliada pelo uso de critérios combinados de ajuste: quadrado médio do resíduo (QMR), erro médio absoluto (EMA) e o critério de informação de Akaike corrigido para tamanhos amostrais pequenos (AICc). Todos os modelos atingiram a convergência para cada caso avaliado. Os critérios de avaliação do modelo logístico indicaram o melhor ajuste geral (0,67 vez dos critérios combinados MSR, MAE e AICc) para cada grupo de peixe avaliado, seguido pelo modelo exponencial (0,185) e os modelos von Bertalanffy e Brody, com 0,074, respectivamente. Similarmente, os resultados de ΔAICc identificaram-se ao modelo logístico e ao de Gompertz, com grande suporte das informações em 100% dos casos. Por fim, o modelo logístico pode ser sugerido na predição do crescimento em comprimento de truta-arco-íris cultivada.(AU)
Asunto(s)
Animales , Oncorhynchus mykiss/crecimiento & desarrollo , Dinámicas no Lineales , Acuicultura/métodos , Modelos LogísticosRESUMEN
Albinism is the most common color variation described in fish and is characterized by a white or yellow phenotype according to the species. In rainbow trout Oncorhynchus mykiss, aside from yellow-albino phenotypes, cobalt blue variants with autosomal, recessive inheritance have also been reported. In this study, we investigated the inheritance pattern and chromatophores distribution/abundance of cobalt blue trouts obtained from a local fish farm. Based on crosses with wild-type and dominant yellow-albino lines, we could infer that cobalt blue are dominant over wild-type and co-dominant in relation to yellow-albino phenotype, resulting in a fourth phenotype: the white-albino. Analysis of chromatophores revealed that cobalt blue trouts present melanophores, as the wild-type, and a reduced number of xanthophores. As regards to the white-albino phenotype, they were not only devoid of melanophores but also presented a reduced number of xanthophores. Cobalt blue and white-albino trouts also presented reduced body weight and a smaller pituitary gland compared to wild-type and yellow-albino phenotypes. The transcription levels of tshb and trh were up regulated in cobalt blue compared to wild type, suggesting the involvement of thyroid hormone in the expression of blue color. These phenotypes represent useful models for research on body pigmentation in salmonids and on the mechanisms behind endocrine control of color patterning.
Asunto(s)
Albinismo/genética , Patrón de Herencia/genética , Oncorhynchus mykiss/genética , Pigmentación/genética , Animales , Cromatóforos/metabolismo , Color , Melanóforos/metabolismo , Oncorhynchus mykiss/crecimiento & desarrollo , FenotipoRESUMEN
Growth is one of the most important traits from both a physiological and economic perspective in aquaculture species. Thus, identifying the genomic regions and genes underpinning genetic variation for this trait is of particular interest in several fish species, including rainbow trout. In this work, we perform a genome-wide association study (GWAS) to identify the genomic regions associated with body weight at tagging (BWT) and at 18 months (BW18M) using a dense SNP panel (57 k) and 4596 genotyped rainbow trout from 105 full-sib families belonging to a Chilean breeding population. Analysis was performed by means of single-step GBLUP approach. Genetic variance explained by 20 adjacent SNP windows across the whole genome is reported. To further explore candidate genes, we focused on windows that explained the highest proportion of genetic variance in the top 10 chromosomes for each trait. The main window from the top 10 chromosomes was explored by BLAST using the first and last SNP position of each window to determine the target nucleotide sequence. As expected, the percentage of genetic variance explained by windows was relatively low, due to the polygenic nature of body weight. The most important genomic region for BWT and BW18M were located on chromosomes 15 and 24 and they explained 2.14% and 3.02% of the genetic variance for each trait, respectively. Candidate genes including several growth factors, genes involved in development of skeletal muscle and bone tissue and nutrient metabolism were identified within the associated regions for both traits BWT and BW18M. These results indicate that body weight is polygenic in nature in rainbow trout, with the most important loci explaining as much as 3% of the genetic variance for the trait. The genes identified here represent good candidates for further functional validation to uncover biological mechanisms underlying variation for growth in rainbow trout.
Asunto(s)
Peso Corporal/genética , Proteínas de Peces/genética , Estudio de Asociación del Genoma Completo/métodos , Oncorhynchus mykiss/genética , Animales , Mapeo Cromosómico , Proteínas de Peces/metabolismo , Genómica/métodos , Genotipo , Herencia Multifactorial/genética , Oncorhynchus mykiss/crecimiento & desarrollo , Oncorhynchus mykiss/metabolismo , Polimorfismo de Nucleótido SimpleRESUMEN
From a physiological-behavioral perspective, it has been shown that fish with a higher density of black eumelanin spots are more dominant, less sensitive to stress, have higher feed intake, better feed efficiency and therefore are larger in size. Thus, we hypothesized that genetic (co)variation between skin pigmentation patterns and growth exists and it is advantageous in rainbow trout. The objective of this study was to determine the genetic relationships between skin pigmentation patterns and BW in a breeding population of rainbow trout. We performed a genetic analysis of pigmentation traits including dorsal color (DC), lateral band (LB) intensity, amount of spotting above (SA) and below (SB) the lateral line, and BW at harvest (HW). Variance components were estimated using a multi-trait linear animal model fitted by restricted maximum likelihood. Estimated heritabilities were 0.08±0.02, 0.17±0.03, 0.44±0.04, 0.17±0.04 and 0.23±0.04 for DC, LB, SA, SB and HW, respectively. Genetic correlations between HW and skin color traits were 0.42±0.13, 0.32±0.14 and 0.25±0.11 for LB, SA and SB, respectively. These results indicate positive, but low to moderate genetic relationships between the amount of spotting and BW in rainbow trout. Thus, higher levels of spotting are genetically associated with better growth performance in this population.
Asunto(s)
Variación Genética , Oncorhynchus mykiss/fisiología , Pigmentación de la Piel/fisiología , Análisis de Varianza , Bienestar del Animal , Animales , Acuicultura/normas , Peso Corporal/genética , Cruzamiento , Ingestión de Alimentos , Femenino , Modelos Lineales , Masculino , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/crecimiento & desarrollo , Fenotipo , Distribución Aleatoria , Selección Genética , Pigmentación de la Piel/genéticaRESUMEN
Fish respond to increasing stocking density as a stressor, adjusting physiological functions to increase energy supply for coping with deleterious effects and adapting. These responses are complex and systemic, and the molecular mechanisms involved remain undetermined. One of the most sensitive organs to environmental and homeostatic disruptions is the intestine, and since it plays several vital functions, understanding the molecular underpinnings of this organ under deleterious conditions is imperative for health improvement in aquaculture systems. This study aimed to understand how different stocking densities of rainbow trout (Oncorhynchus mykiss) modulates the coding and non-coding RNAs profiling, that in turn, play key roles to maintain the fish homeostasis. For this, the intestine tissue of juvenile trout stocked for 30â¯days either at low (LD: 3â¯kgâ¯m-3) or high density (HD: 40â¯kgâ¯m-3) were sampled to isolate total RNA and then construct cDNA libraries for an illumina sequencing platform. Differential gene expression analysis revealed a generalized downregulation of transcripts, including coding and long non-coding RNAs (lncRNAs). Notably, significant differences in transcripts involved in metabolic pathways, as well as immune and epithelium integrity and stability related pathways were found. A high number of downregulated transcripts enriched these pathways, and a strong correlation was observed between the most differentially expressed transcripts and the highly expressed lncRNAs. This study suggests a cross-talk between coding and non-coding RNAs in the intestine of fish exposed to suboptimal conditions, providing new insights into the regulatory role of the lncRNAs on fish response to stressors.
Asunto(s)
Proteínas de Peces/genética , Mucosa Intestinal/metabolismo , Oncorhynchus mykiss/fisiología , Transcriptoma , Animales , Acuicultura , Perfilación de la Expresión Génica , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/crecimiento & desarrollo , ARN Largo no Codificante/genéticaRESUMEN
Rainbow trout is a salmonid specie of commercial importance raised in hatcheries in many countries. Studies over mineral requirements have being perform to guarantee the fulfillment of the nutritional needs and therefore improving the fish farm productions. The aim of this work was to investigate the performance of the elements like Ag, As, Br, Ca, Cr, Cs, Fe, Hg, K, Na, Rb, Se, and Zn, in rainbow trout from a Patagonian fish farming. Body burden of each element in relation to weight were analyzed for identifying potential bioaccumulation or dilution processes. Our results indicated that water and food were the sources for most of the elements, except Se and Ag. Selenium showed the highest value in unfertilized eggs, and Ag was detected in larvae newly after feeding. Toxic elements as Ag, Cr, and Hg were below the regulation standards for human consumption but tend to bioconcentrate in the juvenile state, and the As was during all the growth studied. The macro and micro nutrients assemble the daily requirements for the humans consume, excepting the K.
Asunto(s)
Explotaciones Pesqueras , Metales Pesados/análisis , Micronutrientes/análisis , Oncorhynchus mykiss/crecimiento & desarrollo , Selenio/análisis , Animales , Argentina , HumanosRESUMEN
AIMS: This study used high-throughput sequencing to evaluate the intestinal microbiome dynamics in rainbow trout (Oncorhynchus mykiss) fed commercial diets supplemented with either pre- or probiotics (0·6% mannan-oligosaccharides and 0·5% Saccharomyces cerevisiae respectively) or the mixture of both. METHODS AND RESULTS: A total of 57 fish whole intestinal mucosa and contents bacterial communities were characterized by high-throughput sequencing and analysis of the V3-V4 region of the 16S rRNA gene, as well as the relationship between plasma biochemical health indicators and microbiome diversity. This was performed at 7, 14 and 30 days after start feeding functional diets, and microbiome diversity increased when fish fed functional diets after 7 days and it was positively correlated with plasma cholesterol levels. Dominant phyla were, in descending order, Proteobacteria, Firmicutes, Actinobacteria, Acidobacteria, Bacteroidetes and Fusobacteria. However, functional diets reduced the abundance of Gammaproteobacteria to favour abundances of organisms from Firmicutes and Fusobacteria, two phyla with members that confer beneficial effects. A dynamic shift of the microbiome composition was observed with changes after 7 days of feeding and the modulation by functional diets tend to cluster the corresponding groups apart from CTRL group. The core microbiome showed an overall stability with functional diets, except genus such as Escherichia-Shigella that suffered severe reductions on their abundances when feeding any of the functional diets. CONCLUSIONS: Functional diets based on pre- or probiotics dynamically modulate intestinal microbiota of juvenile trout engaging taxonomical abundance shifts that might impact fish physiological performance. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows for the first time the microbiome modulation dynamics by functional diets based on mannan-oligosaccharides and S. cerevisiae and their synergy using culture independent high-throughput sequencing technology, revealing the complexity behind the dietary modulation with functional feeds in aquatic organisms.
Asunto(s)
Alimentación Animal/microbiología , Bacterias/aislamiento & purificación , Microbioma Gastrointestinal , Oligosacáridos/administración & dosificación , Oncorhynchus mykiss/microbiología , Prebióticos/administración & dosificación , Probióticos/administración & dosificación , Saccharomyces cerevisiae/fisiología , Alimentación Animal/análisis , Animales , Acuicultura , Bacterias/clasificación , Bacterias/genética , Suplementos Dietéticos/análisis , Mucosa Intestinal/microbiología , Mananos/metabolismo , Oncorhynchus mykiss/crecimiento & desarrollo , Probióticos/metabolismo , ARN Ribosómico 16S/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/aislamiento & purificaciónAsunto(s)
Enfermedades de los Peces/microbiología , Enfermedades de los Peces/patología , Enfermedades de los Peces/parasitología , Animales , Acuicultura/métodos , Bacterias Gramnegativas/aislamiento & purificación , Infecciones por Bacterias Gramnegativas/patología , Infecciones por Bacterias Gramnegativas/veterinaria , Mesomycetozoea/aislamiento & purificación , Infecciones por Mesomycetozoea/patología , Oncorhynchus mykiss/crecimiento & desarrollo , PerúRESUMEN
Abstract The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantified through the use of environmental indicators. The nutrient loads, the mass balance, the estimated amount of nutrients in feed and the amount of nutrients converted in fish biomass were calculated based on the concentrations of phosphorus (P) and nitrogen (N) in the feed and in the water. Of the offered feed, 24.75 kg were available as P and 99.00 kg as N, of these, 9.32 kg P (38%) and 29.12 kg N (25%) were converted into fish biomass and 15.43 kg P (62%) and 69.88 kg N (75%) were exported via effluent. The loads and the mass balance show the excessive discharge of nutrients via effluent, corroborated by the feed conversion ratio (2.12:1) due to the low efficiency of feed utilization, therefore, it is proposed the use of this zootechnical parameter as environmental indicator. In addition, feed management practices are not adequate, highlighting the low frequency of feeding during the day, excessive amount and low quality of feed offered. These results demonstrate the need for adequate feed management and the need for careful monitoring of effluent.
Resumo A descarga de fósforo e nitrogênio via efluente do sistema intensivo de truticultura foi quantificada através da utilização de indicadores ambientais. As cargas de nutrientes, o balanço de massa, a quantidade estimada de nutrientes na ração e a quantidade de nutrientes convertidos em biomassa de peixes foram calculados com base nas concentrações de fósforo (P) e nitrogênio (N) na ração e na água. Da ração oferecida, 24,75 kg estavam disponíveis como P e 99,00 kg como N, destes, 9,32 kg de P (38%) e 29,12 kg de N (25%) foram convertidos em biomassa de peixe e 15,43 kg P (62%) e 69,88 kg N (75%) foram exportados via efluente. As cargas e o balanço de massa mostram a descarga excessiva de nutrientes via efluente, corroborado pela taxa de conversão alimentar (2,12:1), devido à baixa eficiência na utilização da ração, portanto, propõe-se a utilização deste parâmetro zootécnico como indicador ambiental. Além disso, as práticas de manejo alimentar não são adequadas, destacando a baixa frequência de alimentação durante o dia, quantidade excessiva e baixa qualidade da alimentação ofertada. Esses resultados demonstram a necessidade de manejo alimentar adequado e de monitoramento do efluente.
Asunto(s)
Animales , Fósforo/análisis , Oncorhynchus mykiss/crecimiento & desarrollo , Explotaciones Pesqueras , Agua Dulce/química , Alimentación Animal/análisis , Nitrógeno/análisis , Contaminantes Químicos del Agua/análisis , Brasil , BiomasaRESUMEN
The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantified through the use of environmental indicators. The nutrient loads, the mass balance, the estimated amount of nutrients in feed and the amount of nutrients converted in fish biomass were calculated based on the concentrations of phosphorus (P) and nitrogen (N) in the feed and in the water. Of the offered feed, 24.75 kg were available as P and 99.00 kg as N, of these, 9.32 kg P (38%) and 29.12 kg N (25%) were converted into fish biomass and 15.43 kg P (62%) and 69.88 kg N (75%) were exported via effluent. The loads and the mass balance show the excessive discharge of nutrients via effluent, corroborated by the feed conversion ratio (2.12:1) due to the low efficiency of feed utilization, therefore, it is proposed the use of this zootechnical parameter as environmental indicator. In addition, feed management practices are not adequate, highlighting the low frequency of feeding during the day, excessive amount and low quality of feed offered. These results demonstrate the need for adequate feed management and the need for careful monitoring of effluent.
Asunto(s)
Alimentación Animal/análisis , Explotaciones Pesqueras , Agua Dulce/química , Nitrógeno/análisis , Oncorhynchus mykiss/crecimiento & desarrollo , Fósforo/análisis , Animales , Biomasa , Brasil , Contaminantes Químicos del Agua/análisisRESUMEN
Biomixtures are used for the removal of pesticides from agricultural wastewater. As biomixtures employ high content of lignocellulosic substrates, their bioaugmentation with ligninolytic fungi represents a novel approach for their enhancement. Nonetheless, the decrease in the concentration of the pesticide may result in sublethal concentrations that still affect ecosystems. Two matrices, a microcosm of rice husk (lignocellulosic substrate) bioaugmented with the fungus Trametes versicolor and a biomixture that contained fungally colonized rice husk were used in the degradation of the insecticide/nematicide carbofuran (CFN). Elutriates simulating lixiviates from these matrices were used to assay the ecotoxicological effects at sublethal level over Daphnia magna (Straus) and the fish Oreochromis aureus (Steindachner) and Oncorhynchus mykiss (Walbaum). Elutriates obtained after 30 d of treatment in the rice husk microcosms at dilutions over 2.5% increased the offspring of D. magna as a trade-off stress response, and produced mortality of neonates at dilutions over 5%. Elutriates (dilution 1:200) obtained during a 30 d period did not produce alterations on the oxygen consumption and ammonium excretion of O. mykiss, however these physiological parameters were affected in O. aureus at every time point of treatment, irrespective of the decrease in CFN concentration. When the fungally colonized rice husk was used to prepare a biomixture, where more accelerated degradation is expected, similar alterations on the responses by O. aureus were achieved. Results suggest that despite the good removal of the pesticide, it is necessary to optimize biomixtures to minimize their residual toxicity and potential chronic effects on aquatic life.
Asunto(s)
Carbofurano/aislamiento & purificación , Ecotoxicología/métodos , Plaguicidas/aislamiento & purificación , Trametes/crecimiento & desarrollo , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Agricultura , Animales , Biodegradación Ambiental , Carbofurano/toxicidad , Cíclidos/crecimiento & desarrollo , Cíclidos/metabolismo , Daphnia/efectos de los fármacos , Daphnia/metabolismo , Oncorhynchus mykiss/crecimiento & desarrollo , Oncorhynchus mykiss/metabolismo , Oryza/microbiología , Plaguicidas/toxicidad , Trametes/metabolismo , Aguas Residuales/química , Contaminantes Químicos del Agua/toxicidadRESUMEN
In this study, we identified myogenic regulatory factors (MRFs) and analyzed the correlation between MRFs and meat quality in rainbow trout. The MyoD1a and MyoD1b genes were cloned from rainbow trout using a homology cloning method. Introns 1 and 2 in the MyoD1a and MyoD1b genes were cloned and submitted to GenBank (accession Nos. FJ623462 and FJ793566). Polymorphisms of MyoD1a and MyoD1b genes were analyzed using single-strand conformation polymorphism and sequencing, respectively. Two single nucleotide polymorphisms were detected in the MyoD1 gene, located at 129GâA in exon 1 and 37 GâA in exon 2. The 37 GâA mutation in exon 2 induced the R185K amino acid change in the polypeptide chain. Seven single nucleotide polymorphisms in the MyoD2 gene were detected, including 218TâC, 224TâC, 242AâC, 246TâA, 248TâC, 305TâC, and 329CâT. The 246TâA mutation in exon 1 induced the R83K change in the polypeptide chain. In the S3 fragment, meat quality traits of genotypes AA and AB significantly differed from those of genotype BB (P < 0.05). In the S5 fragment, meat quality traits of the genotypes AA and AC were significantly different from the genotypes BB and BC (P < 0.05). These results indicate that the MyoD1a and MyoD1b genes have an important influence on meat quality or were linked to the major genes in these strains. These genes can be used to control muscle fiber traits in rainbow trout, and the mutations in the S3 and S5 fragments can be used as molecular markers for selecting rainbow trout with better meat quality traits.
Asunto(s)
Estudios de Asociación Genética , Carne , Proteína MioD/genética , Oncorhynchus mykiss/genética , Animales , Secuencia de Bases , Exones , Genotipo , Oncorhynchus mykiss/crecimiento & desarrollo , Fenotipo , Polimorfismo de Nucleótido SimpleRESUMEN
MicroRNAs are ubiquitous, short, non-coding RNA molecules that function as post-transcriptional regulators of gene expression in a variety of biological processes. In order to further our understanding of the microRNA hierarchy in the reproductive axis of male teleosts, four small RNA libraries were constructed, and sequenced from the testis and brain of sexually mature adults and immature juvenile rainbow trout (Oncorhynchus mykiss) using Illumina small-RNA deep sequencing. We obtained 56,632,987; 39,870,661; 82,454,370; and 53,143,465 high-quality, filtered reads for immature testis, mature testis, immature brain, and mature brain, respectively. Among the libraries, 433 known mature piscine miRNAs were identified, with 124 and 116 significantly differentially expressed miRNAs found between sexually immature/mature testes and immature/mature brain tissues, respectively. Among these differentially expressed miRNAs, miR-129, -130c, -135b, -140, -146a, -192, -199a, -16, and, -19b showed higher abundance in the testis whereas miR-10b, -183, -199, -375, -1937, and miR-nov210 were more abundant in the brain. In silico target prediction of these differentially expressed miRNAs suggested their putative roles in the sexual maturation of male rainbow trout.
Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento/métodos , MicroARNs/genética , Oncorhynchus mykiss/crecimiento & desarrollo , Oncorhynchus mykiss/genética , Análisis de Secuencia de ARN/métodos , Maduración Sexual/genética , Animales , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Perfilación de la Expresión Génica , Masculino , Testículo/crecimiento & desarrollo , Testículo/metabolismoRESUMEN
Members of the TGF-ß superfamily are involved in numerous cell functions; however, except for myostatin, their roles in the regulation of muscle growth in fish are completely unknown. We measured tgf-ß1, tgf-ß2, tgf-ß3, inhibin ßA (inh) and follistatin (fst) gene expression during muscle growth recovery following a fasting period. We observed that tgf-ß1a and tgf-ß2 expression were quickly down-regulated after refeeding and that tgf-ß3 reached its highest level of expression 7days post-refeeding, mirroring myogenin expression. Inh ßA1 mRNA levels decreased sharply after refeeding, in contrast to fst b2 expression, which peaked at day 2. No significant modification of expression was observed for tgf-ß1a, tgf-ß1b, tgf-ß1c and tgf-ß6 during refeeding. In vitro, tgf-ß2 and inh ßA1 expression decreased during the differentiation of satellite cells, whereas tgf-ß3 expression increased following the same pattern as myogenin. Surprisingly, fst b1 and fst b2 expression decreased during differentiation, whereas no variation was observed in fst a1 and fst a2 expression levels. In vitro analyses also indicated that IGF1 treatment up-regulated tgf-ß3, inh ßA1 and myogenin expression, and that MSTN treatment increased fst b1 and fst b2 expression. In conclusion, we showed that the expression of tgf-ß2, tgf-ß3 and inh ßA1 is dynamically regulated during muscle growth resumption and satellite cell differentiation, strongly suggesting that these genes have a role in the regulation of muscle growth.
Asunto(s)
Diferenciación Celular/genética , Subunidades beta de Inhibinas/genética , Desarrollo de Músculos/genética , Oncorhynchus mykiss , Células Satélite del Músculo Esquelético/fisiología , Factor de Crecimiento Transformador beta2/genética , Factor de Crecimiento Transformador beta3/genética , Animales , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Hormona del Crecimiento/farmacología , Subunidades beta de Inhibinas/metabolismo , Factor I del Crecimiento Similar a la Insulina/farmacología , Músculos/efectos de los fármacos , Músculos/fisiología , Miostatina/farmacología , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/crecimiento & desarrollo , Oncorhynchus mykiss/metabolismo , Células Satélite del Músculo Esquelético/efectos de los fármacos , Factor de Crecimiento Transformador beta2/metabolismo , Factor de Crecimiento Transformador beta3/metabolismoRESUMEN
Genetic parameters and breeding values for growth traits were estimated in the first and, currently, the only family selective breeding program for rainbow trout (Oncorhynchus mykiss) in China. Genetic and phenotypic data were collected for growth traits from 75 full-sibling families with a 2-generation pedigree. Genetic parameters and breeding values for growth traits of rainbow trout were estimated using the derivative-free restricted maximum likelihood method. The goodness-of-fit of the models was tested using Akaike and Bayesian information criteria. Genetic parameters and breeding values were estimated using the best-fit model for each trait. The values for heritability estimating body weight and length ranged from 0.20 to 0.45 and from 0.27 to 0.60, respectively, and the heritability of condition factor was 0.34. Our results showed a moderate degree of heritability for growth traits in this breeding program and suggested that the genetic and phenotypic tendency of body length, body weight, and condition factor were similar. Therefore, the selection of phenotypic values based on pedigree information was also suitable in this research population.
Asunto(s)
Cruzamiento , Oncorhynchus mykiss/crecimiento & desarrollo , Oncorhynchus mykiss/genética , Carácter Cuantitativo Heredable , Animales , China , Femenino , Estudios de Asociación Genética , Masculino , Modelos EstadísticosRESUMEN
The δ(15) N isotopic change of recently emerged rainbow trout Oncorhynchus mykiss due to diet shift from yolk sac to exogenous feeding was evaluated in a field study. The fit of a general model including both fish length and age in days as co-variables indicates that the specific δ(15) N of individual fish at any given time along the ontogeny is determined by its growth trajectory. The results suggest that estimations based on fish size alone could bias data interpretation and maternal origin determinations in partially migratory salmonids.
Asunto(s)
Dieta , Oncorhynchus mykiss/crecimiento & desarrollo , Animales , Tamaño Corporal , Modelos Estadísticos , Isótopos de Nitrógeno/análisis , Membrana Otolítica/crecimiento & desarrolloRESUMEN
Background: Carotenoids such as ß-carotene, α-carotene, lycopene, lutein and ß-cryptoxanthin are a family of pigmented compounds which are synthesized by many vegetable crops and microorganisms but not animals. In human and murine models, carotenoids are shown to mediate their effects via different mechanisms such as gap junction communication, cell growth regulation, modulating gene expression and immune response. In some fish species, the immunomodulating action of synthetic carotenoids has been the subject of some research. How ever, studies on the effects of carotenoids from natural sources on fish growth performance and immune parameters are lacking. In the current study, a preliminary study with 60 days feeding was conducted to study the influence of different natural sources of carotenoids from some vegetable crops on growth and some immune indices in rainbow trout (Oncorhynchus mykiss). Materials, Methods & Results: Purified isonitrigenous (crude protein: 40.16%) and isocaloric (3660 kcal kg-1) diet with 4.5 g of powdered crops namely tomato (Solanum lycopersicum) and sweet pepper (Capsicum annuum) per kg feed or control diet without any treatment was prepared. Rainbow trout weighing 150 ± 9 g were distributed equally into 2 groups with 33 fish in each group. Each group contained 11 fish in triplicate reared in individual ponds. In treatment group, fish were fed diet containing 4.5 g of powdered crops for 60 days while in control group, basal diet without any treatments was fed. At the end of the feeding trial, 4 fish per tank were sampled to analyze the growth parameters. Seven fish were also bled from the caudal vein to collect serum sample for immune parameters. During this study no mortality of fish was observed in different groups. Results of this study showed that condition factor and feed intake were similar among the groups while specific growth rate and weight gain showed a significant increase in treatment group compared to control group. Immunological parameters namely peroxidase content, antibacterial activity, α1-antiprotease, total antiprotease activities and total protein did not vary among the groups, even though slight decrease in serum peroxidase content was shown in treatment group. On the other hand, serum lysozyme activity of fish fed treatment diet was significantly higher than control group. Discussion: Enhanced growth performance in the current study might be attributed to some intermediary metabolism which could enhance nutrient utilization and may ultimately result in improved fi sh growth. Lysozyme is secreted by leukocytes and is a marker of leukocyte activity, increasing concomitantly with phagocytic activity. Administration of natural carotenoids in fish diet exerts a stabilizing or protective effect against oxidative damage, and enhances the proliferation of these cells, which could result in increased serum lysozyme level. Feeding natural carotenoids might act as a direct scavenger of reactive oxygen species and decrease the body's need for certain antioxidant enzymes. Therefore, slight decrease in serum peroxidase content can be attributed to this point. In conclusion, this study showed that rainbow trout appear to benefit from inclusion of crops in diet in terms of improved growth performance and immune system.
Asunto(s)
Animales , Carotenoides/efectos adversos , Oncorhynchus mykiss/crecimiento & desarrollo , Dietoterapia/veterinaria , Sistema Inmunológico , Capsicum , Solanum lycopersicumRESUMEN
Using genetic monosex male and female rainbow trout populations, the potential sex differences in the central expression of estrogen receptors (esr1, esr2a, esr2b), brain aromatase (cyp19a1b) and some other steroidogenic enzymes was studied over the period of sex differentiation (from 35 to 63 dpf: days post-fertilization) using quantitative polymerase chain reaction (q-PCR). In addition, aromatase activity was evaluated during this period. The results indicated that brain aromatase (cyp19a1b) expression and activity showed a clear and significant sexually dimorphic pattern with higher levels in male brain between 35 and 53 dpf before the time of gonad morphological differentiation. At that time the expression of a key enzyme involved in the conversion of cholesterol into steroids, the cyp11a1 (p450scc), as well as the estrogen receptors were also sexually dimorphic. The dimorphism was lost from 56 dpf onwards. Transcription factors such as nr5a1b (sf1) and nr0b1 (dax1), but not foxl2a were also higher in males than in females. These results demonstrate that, before or during the early period of morphological gonad differentiation, the brain exhibits a clear sexual dimorphism with respect to the expression and activity of aromatase as well as of certain enzymes and factors involved in steroid synthesis as p450scc and sf1. The results suggest a higher potentiality to produce estrogens by male brains during sex differentiation time.
Asunto(s)
Aromatasa/metabolismo , Encéfalo/enzimología , Proteínas de Peces/metabolismo , Oncorhynchus mykiss/metabolismo , Caracteres Sexuales , Diferenciación Sexual , Animales , Aromatasa/genética , Colesterol/metabolismo , Femenino , Proteínas de Peces/genética , Masculino , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/crecimiento & desarrollo , ARN Mensajero/metabolismo , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismoRESUMEN
The sexual plasticity of fish gonads declines after the sex-differentiation period; however, the plasticity of the germ cells themselves after this stage remains poorly understood. We characterized the sexual plasticity of gonial germ cells by transplanting them into sexually undifferentiated embryonic gonads in rainbow trout (Oncorhynchus mykiss). Spermatogonia or oogonia isolated from the meiotic gonads of vasa-green fluorescent protein (Gfp) gene transgenic trout were transplanted into the peritoneal cavity of newly hatched embryos of both sexes, and the behavior of the GFPlabeled donor cells was observed. The transplanted spermatogonia and oogonia migrated towards the recipient gonadal anlagen, and were subsequently incorporated into them. We also confirmed that the donor-derived gonial germ cells resumed gametogenesis in the recipient somatic microenvironment synchronously with the endogenous germ cells. Surprisingly, the donor-derived spermatogonia started to proliferate and differentiate into oocytes in female recipients. At 2 years post-transplantation, the eggs from mature female recipients were artificially inseminated with sperm from intact male rainbow trout. Normal, live offspring with the donor-derived haplotype were obtained. In addition, oogonia-derived sperm were produced in the male recipients. These donor-derived sperm were shown to be fully functional, as live offspring carrying GFP-labeled germ cells with the donor haplotype were obtained in the first filial (F1) generation. These findings indicate that rainbow trout pre-meiotic germ cells, which are likely to be spermatogonial or oogonial stem cells, possess a high level of sexual plasticity, and that the sexual differentiation of germ cells is controlled solely by the somatic microenvironment, rather than being cell autonomous.