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1.
PLoS One ; 15(1): e0214034, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31986190

RESUMO

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.


Assuntos
Albinismo/genética , Padrões de Herança/genética , Oncorhynchus mykiss/genética , Pigmentação/genética , Animais , Cromatóforos/metabolismo , Cor , Melanóforos/metabolismo , Oncorhynchus mykiss/crescimento & desenvolvimento , Fenótipo
2.
Genes (Basel) ; 11(1)2019 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-31878086

RESUMO

In stock enhancement and sea-ranching procedures, the adipose fin of hundreds of millions of salmonids is removed for marking purposes annually. However, recent studies proved the significance of the adipose fin as a flow sensor and attraction feature. In the present study, we profiled the specific expression of 20 neuron- and glial cell-marker genes in the adipose fin and seven other tissues (including dorsal and pectoral fin, brain, skin, muscle, head kidney, and liver) of the salmonid species rainbow trout Oncorhynchus mykiss and maraena whitefish Coregonus maraena. Moreover, we measured the transcript abundance of genes coding for 15 mechanoreceptive channel proteins from a variety of mechanoreceptors known in vertebrates. The overall expression patterns indicate the presence of the entire repertoire of neurons, glial cells and receptor proteins on the RNA level. This quantification suggests that the adipose fin contains considerable amounts of small nerve fibers with unmyelinated or slightly myelinated axons and most likely mechanoreceptive potential. The findings are consistent for both rainbow trout and maraena whitefish and support a previous hypothesis about the innervation and potential flow sensory function of the adipose fin. Moreover, our data suggest that the resection of the adipose fin has a stronger impact on the welfare of salmonid fish than previously assumed.


Assuntos
Nadadeiras de Animais/fisiologia , Oncorhynchus mykiss/genética , Adiposidade/genética , Adiposidade/fisiologia , Nadadeiras de Animais/metabolismo , Bem-Estar do Animal , Animais , Fígado , Mecanorreceptores/fisiologia , Oncorhynchus mykiss/metabolismo , Salmonidae/genética , Salmonidae/fisiologia , Pele , Transcriptoma/genética
3.
G3 (Bethesda) ; 9(11): 3833-3841, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31690599

RESUMO

One of the main pathogens affecting rainbow trout (Oncorhynchus mykiss) farming is the facultative intracellular bacteria Piscirickettsia salmonis Current treatments, such as antibiotics and vaccines, have not had the expected effectiveness in field conditions. Genetic improvement by means of selection for resistance is proposed as a viable alternative for control. Genomic information can be used to identify the genomic regions associated with resistance and enhance the genetic evaluation methods to speed up the genetic improvement for the trait. The objectives of this study were to i) identify the genomic regions associated with resistance to P. salmonis; and ii) identify candidate genes associated with the trait in rainbow trout. We experimentally challenged 2,130 rainbow trout with P. salmonis and genotyped them with a 57 K single nucleotide polymorphism (SNP) array. Resistance to P. salmonis was defined as time to death (TD) and as binary survival (BS). Significant heritabilities were estimated for TD and BS (0.48 ± 0.04 and 0.34 ± 0.04, respectively). A total of 2,047 fish and 26,068 SNPs passed quality control for samples and genotypes. Using a single-step genome wide association analysis (ssGWAS) we identified four genomic regions explaining over 1% of the genetic variance for TD and three for BS. Interestingly, the same genomic region located on Omy27 was found to explain the highest proportion of genetic variance for both traits (2.4 and 1.5% for TD and BS, respectively). The identified SNP in this region is located within an exon of a gene related with actin cytoskeletal organization, a protein exploited by P. salmonis during infection. Other important candidate genes identified are related with innate immune response and oxidative stress. The moderate heritability values estimated in the present study show it is possible to improve resistance to P. salmonis through artificial selection in the rainbow trout population studied here. Furthermore, our results suggest a polygenic genetic architecture for the trait and provide novel insights into the candidate genes underpinning resistance to P. salmonis in O. mykiss.


Assuntos
Resistência à Doença/genética , Doenças dos Peixes/genética , Oncorhynchus mykiss/genética , Piscirickettsia , Infecções por Piscirickettsiaceae/genética , Animais , Estudo de Associação Genômica Ampla , Genótipo , Oncorhynchus mykiss/microbiologia , Infecções por Piscirickettsiaceae/veterinária , Polimorfismo de Nucleotídeo Único
4.
Aquat Toxicol ; 217: 105347, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31715476

RESUMO

The simultaneous presence of natural and anthropogenic stressors in aquatic ecosystems can challenge the identification of factors causing decline in fish populations. These stressors include chemical mixtures and natural abiotic and biotic factors such as water temperature and parasitism. Effects of cumulative stressors may vary from antagonism to synergism at the organismal or population levels and may not be predicted from exposure to individual stressors. This study aimed to evaluate the combined effects of chronic exposure to cadmium (Cd) and elevated water temperature (23 °C) or parasite infection in juvenile rainbow trout (Oncorhynchus mykiss) using a multi-level biological approach, including RNA-sequencing. Fish were exposed to diet-borne Cd (6 µg Cd/g wet feed), individually and in combination with thermal (23 °C) or parasitic stressors, for 28 days. The parasite challenge consisted of a single exposure to glochidia (larvae) of the freshwater mussel (Strophitus undulatus), which encysts in fish gills, fins and skin. Results indicated lower fish length, weight, and relative growth rate in fish exposed to a higher water temperature (23 °C). Body condition and hepatosomatic index of trout were, however, higher in the 23 °C temperature treatment compared to the control fish kept at 15 °C. Exposure to thermal stress or parasitism did not influence tissue Cd bioaccumulation. More than 700 genes were differentially transcribed in fish exposed to the individual thermal stress treatment. However, neither Cd exposure nor parasite infection affected the number of differentially transcribed genes, compared to controls. The highest number of differentially transcribed genes (969 genes) was observed in trout exposed to combined Cd and high temperature stressors; these genes were mainly related to stress response, protein folding, calcium metabolism, bone growth, energy metabolism, and immune system; functions overlapped with responses found in fish solely exposed to higher water temperature. Only 40 genes were differentially transcribed when fish were exposed to Cd and glochidia and were related to the immune system, apoptosis process, energy metabolism and malignant tumor. These results suggest that dietary Cd may exacerbate the temperature stress and, to a lesser extent, parasitic infection stress on trout transcriptomic responses. Changes in the concentrations of liver ethoxyresorufin-o-deethylase, heat shock protein 70 and thiobarbituric acid reactive substances coupled to changes in the activities of cellular glutathione S-transferase and glucose-6-phosphate dehydrogenase were also observed at the cellular level. This study may help understand effects of freshwater fish exposure to cumulative stressors in a changing environment.


Assuntos
Cádmio/toxicidade , Água Doce/química , Oncorhynchus mykiss/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Doenças Parasitárias em Animais/metabolismo , Temperatura , Poluentes Químicos da Água/toxicidade , Animais , Citocromo P-450 CYP1A1/metabolismo , Ecossistema , Feminino , Doenças dos Peixes , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Brânquias/parasitologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/parasitologia , Estresse Oxidativo/genética , Doenças Parasitárias em Animais/genética , Transcriptoma/efeitos dos fármacos
5.
BMC Genomics ; 20(1): 788, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664902

RESUMO

BACKGROUND: Diverse microbial communities colonizing the intestine of fish contribute to their growth, digestion, nutrition, and immune function. We hypothesized that fecal samples representing the gut microbiota of rainbow trout could be associated with differential growth rates observed in fish breeding programs. If true, harnessing the functionality of this microbiota can improve the profitability of aquaculture. The first objective of this study was to test this hypothesis if gut microbiota is associated with fish growth rate (body weight). Four full-sibling families were stocked in the same tank and fed an identical diet. Two fast-growing and two slow-growing fish were selected from each family for 16S rRNA microbiota profiling. Microbiota diversity varies with different DNA extraction methods. The second objective of this study was to compare the effects of five commonly used DNA extraction methods on the microbiota profiling and to determine the most appropriate extraction method for this study. These methods were Promega-Maxwell, Phenol-chloroform, MO-BIO, Qiagen-Blood/Tissue, and Qiagen-Stool. Methods were compared according to DNA integrity, cost, feasibility and inter-sample variation based on non-metric multidimensional scaling ordination (nMDS) clusters. RESULTS: Differences in DNA extraction methods resulted in significant variation in the identification of bacteria that compose the gut microbiota. Promega-Maxwell had the lowest inter-sample variation and was therefore used for the subsequent analyses. Beta diversity of the bacterial communities showed significant variation between breeding families but not between the fast- and slow-growing fish. However, an indicator analysis determined that cellulose, amylose degrading and amino acid fermenting bacteria (Clostridium, Leptotrichia, and Peptostreptococcus) are indicator taxa of the fast-growing fish. In contrary, pathogenic bacteria (Corynebacterium and Paeniclostridium) were identified as indicator taxa for the slow-growing fish. CONCLUSION: DNA extraction methodology should be carefully considered for accurate profiling of the gut microbiota. Although the microbiota was not significantly different between the fast- and slow-growing fish groups, some bacterial taxa with functional implications were indicative of fish growth rate. Further studies are warranted to explore how bacteria are transmitted and potential usage of the indicator bacteria of fast-growing fish for development of probiotics that may improve fish health and growth.


Assuntos
Microbioma Gastrointestinal , Oncorhynchus mykiss/microbiologia , Animais , DNA/isolamento & purificação , Fezes/microbiologia , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/crescimento & desenvolvimento
6.
PLoS One ; 14(9): e0223018, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31539414

RESUMO

In studying the causative mechanisms behind migration and life history, the salmonids-salmon, trout, and charr-are an exemplary taxonomic group, as life history development is known to have a strong genetic component. A double inversion located on chromosome 5 in rainbow trout (Oncorhynchus mykiss) is associated with life history development in multiple populations, but the importance of this inversion has not been thoroughly tested in conjunction with other polymorphisms in the genome. To that end, we used a high-density SNP chip to genotype 192 F1 migratory and resident rainbow trout and focused our analyses to determine whether this inversion is important in life history development in a well-studied population of rainbow trout from Southeast Alaska. We identified 4,994 and 436 SNPs-predominantly outside of the inversion region-associated with life history development in the migrant and resident familial lines, respectively. Although F1 samples showed genomic patterns consistent with the double inversion on chromosome 5 (reduced observed and expected heterozygosity and an increase in linkage disequilibrium), we found no statistical association between the inversion and life history development. Progeny produced by crossing resident trout and progeny produced by crossing migrant trout both consisted of a mix of migrant and resident individuals, irrespective of the individuals' inversion haplotype on chromosome 5. This suggests that although the inversion is present at a low frequency, it is not strongly associated with migration as it is in populations of Oncorhynchus mykiss from lower latitudes.


Assuntos
Inversão Cromossômica , Genoma/genética , Genômica/métodos , Oncorhynchus mykiss/genética , Alaska , Migração Animal , Animais , Genética Populacional , Genótipo , Geografia , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único
7.
Aquat Toxicol ; 215: 105282, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31509759

RESUMO

Aquatic ecosystems are now chronically polluted by a cocktail of many chemical substances. There is now clear evidence of associations between exposure to pollutants and greater susceptibility to pathogens. The aim of the present study was to characterize the defense capacities of rainbow trout (Oncorhynchus mykiss), chronically exposed to pendimethalin (PD), to subsequent experimental challenge with the infectious hematopoietic necrosis virus (IHNV). Immunological responses were examined at different organizational levels, from individuals to gene expression. No negative effects of PD were noted on the Fulton index nor on the liver or spleen somatic indices (LSI; SSI) before viral infection, but the infectious stress seems to generate a weak but significant decrease in Fulton and LSI values, which could be associated with consumption of energy reserves. During the viral challenges, the distribution of cumulative mortality was slightly different between infected groups. The impact of the virus on fish previously contaminated by PD started earlier and lasted longer than controls. The proportion of seropositive fish was lower in the fish group exposed to PD than in the control group, with similar quantities of anti-IHNV antibodies secreted in positive fish, regardless of the treatment. While no significant differences in C3-1 expression levels were detected throughout the experiment, TNF1&2, TLR3, Il-1ß and IFN expression levels were increased in all infected fish, but the difference was more significant in fish groups previously exposed to herbicide. On the other hand, ß-def expression was decreased in the pendimethalin-IHNV group compared to that in fish only infected by the virus (control-IHNV group).


Assuntos
Herbicidas/toxicidade , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Vírus da Necrose Hematopoética Infecciosa/fisiologia , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/imunologia , Infecções por Rhabdoviridae/imunologia , Infecções por Rhabdoviridae/veterinária , Compostos de Anilina/toxicidade , Animais , Doenças dos Peixes/genética , Doenças dos Peixes/imunologia , Doenças dos Peixes/virologia , Regulação da Expressão Gênica/efeitos dos fármacos , Oncorhynchus mykiss/virologia , Infecções por Rhabdoviridae/genética , Infecções por Rhabdoviridae/patologia , Poluentes Químicos da Água/toxicidade
8.
Fish Shellfish Immunol ; 93: 631-640, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31377431

RESUMO

Fish aquaculture is the world's fastest growing food production industry and infectious diseases are a major limiting factor. Vaccination is the most appropriate method for controlling infectious diseases and a key reason for the success of salmonid cultivation and has reduced the use of antibiotics. The development of fish vaccines requires the use of a great number of experimental animals that are challenged with virulent pathogens. In vitro cell culture systems have the potential to replace in vivo pathogen exposure for initial screening and testing of novel vaccine candidates/preparations, and for batch potency and safety tests. PBL contain major immune cells that enable the detection of both innate and adaptive immune responses in vitro. Fish PBL can be easily prepared using a hypotonic method and is the only way to obtain large numbers of immune cells non-lethally. Distinct gene expression profiles of innate and adaptive immunity have been observed between bacterins prepared from different bacterial species, as well as from different strains or culturing conditions of the same bacterial species. Distinct immune pathways are activated by pathogens or vaccines in vivo that can be detected in PBL in vitro. Immune gene expression in PBL after stimulation with vaccine candidates may shed light on the immune pathways involved that lead to vaccine-mediated protection. This study suggests that PBL are a suitable platform for initial screening of vaccine candidates, for evaluation of vaccine-induced immune responses, and a cheap alternative for potency testing to reduce animal use in aquaculture vaccine development.


Assuntos
Aquicultura/métodos , Vacinas Bacterianas/imunologia , Doenças dos Peixes/prevenção & controle , Expressão Gênica/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/imunologia , Aeromonas salmonicida/imunologia , Animais , Vacinas Bacterianas/administração & dosagem , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/prevenção & controle , Técnicas In Vitro/métodos , Leucócitos/imunologia , Yersinia ruckeri/imunologia
9.
Genet Sel Evol ; 51(1): 47, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31455244

RESUMO

BACKGROUND: Infectious hematopoietic necrosis (IHN) is a disease of salmonid fish that is caused by the IHN virus (IHNV). Under intensive aquaculture conditions, IHNV can cause significant mortality and economic losses. Currently, there is no proven and cost-effective method for IHNV control. Clear Springs Foods, Inc. has been applying selective breeding to improve genetic resistance to IHNV in their rainbow trout breeding program. The goals of this study were to elucidate the genetic architecture of IHNV resistance in this commercial population by performing genome-wide association studies (GWAS) with multiple regression single-step methods and to assess if genomic selection can improve the accuracy of genetic merit predictions over conventional pedigree-based best linear unbiased prediction (PBLUP) using cross-validation analysis. RESULTS: Ten moderate-effect quantitative trait loci (QTL) associated with resistance to IHNV that jointly explained up to 42% of the additive genetic variance were detected in our GWAS. Only three of the 10 QTL were detected by both single-step Bayesian multiple regression (ssBMR) and weighted single-step GBLUP (wssGBLUP) methods. The accuracy of breeding value predictions with wssGBLUP (0.33-0.39) was substantially better than with PBLUP (0.13-0.24). CONCLUSIONS: Our comprehensive genome-wide scan for QTL revealed that genetic resistance to IHNV is controlled by the oligogenic inheritance of up to 10 moderate-effect QTL and many small-effect loci in this commercial rainbow trout breeding population. Taken together, our results suggest that whole genome-enabled selection models will be more effective than the conventional pedigree-based method for breeding value estimation or the marker-assisted selection approach for improving the genetic resistance of rainbow trout to IHNV in this population.


Assuntos
Doenças dos Peixes/genética , Vírus da Necrose Hematopoética Infecciosa , Oncorhynchus mykiss/genética , Infecções por Rhabdoviridae/veterinária , Animais , Teorema de Bayes , Cruzamento , Cruzamentos Genéticos , Resistência à Doença/genética , Doenças dos Peixes/virologia , Pesqueiros , Estudo de Associação Genômica Ampla/veterinária , Herança Multifatorial , Oncorhynchus mykiss/virologia , Locos de Características Quantitativas , Infecções por Rhabdoviridae/genética
10.
Genet Sel Evol ; 51(1): 42, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31387519

RESUMO

BACKGROUND: Columnaris disease (CD) is an emerging problem for the rainbow trout aquaculture industry in the US. The objectives of this study were to: (1) identify common genomic regions that explain a large proportion of the additive genetic variance for resistance to CD in two rainbow trout (Oncorhynchus mykiss) populations; and (2) estimate the gains in prediction accuracy when genomic information is used to evaluate the genetic potential of survival to columnaris infection in each population. METHODS: Two aquaculture populations were investigated: the National Center for Cool and Cold Water Aquaculture (NCCCWA) odd-year line and the Troutlodge, Inc., May odd-year (TLUM) nucleus breeding population. Fish that survived to 21 days post-immersion challenge were recorded as resistant. Single nucleotide polymorphism (SNP) genotypes were available for 1185 and 1137 fish from NCCCWA and TLUM, respectively. SNP effects and variances were estimated using the weighted single-step genomic best linear unbiased prediction (BLUP) for genome-wide association. Genomic regions that explained more than 1% of the additive genetic variance were considered to be associated with resistance to CD. Predictive ability was calculated in a fivefold cross-validation scheme and using a linear regression method. RESULTS: Validation on adjusted phenotypes provided a prediction accuracy close to zero, due to the binary nature of the trait. Using breeding values computed from the complete data as benchmark improved prediction accuracy of genomic models by about 40% compared to the pedigree-based BLUP. Fourteen windows located on six chromosomes were associated with resistance to CD in the NCCCWA population, of which two windows on chromosome Omy 17 jointly explained more than 10% of the additive genetic variance. Twenty-six windows located on 13 chromosomes were associated with resistance to CD in the TLUM population. Only four associated genomic regions overlapped with quantitative trait loci (QTL) between both populations. CONCLUSIONS: Our results suggest that genome-wide selection for resistance to CD in rainbow trout has greater potential than selection for a few target genomic regions that were found to be associated to resistance to CD due to the polygenic architecture of this trait, and because the QTL associated with resistance to CD are not sufficiently informative for selection decisions across populations.


Assuntos
Cruzamento , Mapeamento Cromossômico , Doenças dos Peixes/genética , Infecções por Flavobacteriaceae/veterinária , Flavobacterium , Oncorhynchus mykiss/genética , Animais , Resistência à Doença/genética , Feminino , Pesqueiros , Infecções por Flavobacteriaceae/genética , Padrões de Herança , Masculino , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Seleção Genética
11.
Mol Ecol ; 28(16): 3738-3755, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31294488

RESUMO

Hybridization can profoundly affect the genomic composition and phenotypes of closely related species, and provides an opportunity to identify mechanisms that maintain reproductive isolation between species. Recent evidence suggests that hybridization outcomes within a species pair can vary across locations. However, we still do not know how variable outcomes of hybridization are across geographic replicates, and what mechanisms drive that variation. In this study, we described hybridization outcomes across 27 locations in the North Fork Shoshone River basin (Wyoming, USA) where native Yellowstone cutthroat trout and introduced rainbow trout co-occur. We used genomic data and hierarchical Bayesian models to precisely identify ancestry of hybrid individuals. Hybridization outcomes varied across locations. In some locations, only rainbow trout and advanced backcrossed hybrids towards rainbow trout were present, while trout in other locations had a broader range of ancestry, including both parental species and first-generation hybrids. Later-generation intermediate hybrids were rare relative to backcrossed hybrids and rainbow trout individuals. Using an individual-based simulation, we found that outcomes of hybridization in the North Fork Shoshone River basin deviate substantially from what we would expect under null expectations of random mating and no selection against hybrids. Since this deviation implies that some mechanisms of reproductive isolation function to maintain parental taxa and a diversity of hybrid types, we then modelled hybridization outcomes as a function of environmental variables and stocking history that are likely to affect prezygotic barriers to hybridization. Variables associated with history of fish stocking were the strongest predictors of hybridization outcomes, followed by environmental variables that might affect overlap in spawning time and location.


Assuntos
Hibridização Genética , Oncorhynchus mykiss/genética , Oncorhynchus/genética , Isolamento Reprodutivo , Animais , Teorema de Bayes , Simulação por Computador , Meio Ambiente , Modelos Genéticos , Rios , Wyoming
12.
G3 (Bethesda) ; 9(9): 2897-2904, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31324747

RESUMO

Infectious pancreatic necrosis (IPN) is a viral disease with considerable negative impact on the rainbow trout (Oncorhynchus mykiss) aquaculture industry. The aim of the present work was to detect genomic regions that explain resistance to infectious pancreatic necrosis virus (IPNV) in rainbow trout. A total of 2,278 fish from 58 full-sib families were challenged with IPNV and 768 individuals were genotyped (488 resistant and 280 susceptible), using a 57K SNP panel Axiom, Affymetrix. A genome-wide association study (GWAS) was performed using the phenotypes time to death (TD) and binary survival (BS), along with the genotypes of the challenged fish using a Bayesian model (Bayes C). Heritabilities for resistance to IPNV estimated using genomic information, were 0.53 and 0.82 for TD and BS, respectively. The Bayesian GWAS detected a SNP located on chromosome 5 explaining 19% of the genetic variance for TD. The proximity of Sentrin-specific protease 5 (SENP5) to this SNP makes it a candidate gene for resistance against IPNV. In case of BS, a SNP located on chromosome 23 was detected explaining 9% of the genetic variance. However, the moderate-low proportion of variance explained by the detected marker leads to the conclusion that the incorporation of all genomic information, through genomic selection, would be the most appropriate approach to accelerate genetic progress for the improvement of resistance against IPNV in rainbow trout.


Assuntos
Resistência à Doença/genética , Doenças dos Peixes/virologia , Proteínas de Peixes/genética , Vírus da Necrose Pancreática Infecciosa/fisiologia , Oncorhynchus mykiss/genética , Animais , Teorema de Bayes , Infecções por Birnaviridae/genética , Infecções por Birnaviridae/imunologia , Infecções por Birnaviridae/mortalidade , Infecções por Birnaviridae/veterinária , Doenças dos Peixes/imunologia , Doenças dos Peixes/mortalidade , Proteínas de Peixes/imunologia , Estudo de Associação Genômica Ampla , Interações Hospedeiro-Patógeno/genética , Vírus da Necrose Pancreática Infecciosa/patogenicidade , Oncorhynchus mykiss/imunologia , Oncorhynchus mykiss/virologia , Polimorfismo de Nucleotídeo Único , Replicação Viral/fisiologia
13.
Fish Shellfish Immunol ; 93: 1056-1066, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31340170

RESUMO

In mammals, the multifunctional DExH/D-box helicases, DDX3 and DHX9, are nucleic acid sensors with a role in antiviral immunity; their role in innate immunity in fish is not yet understood. In the present study, full-length DDX3 and DHX9 coding sequences were identified in rainbow trout (Oncorhynchus mykiss). Bioinformatic analysis demonstrated both deduced proteins were similar to those of other species, with ~80% identity to other fish species and ~70-75% identity to mammals, and both protein sequences had conserved domains found amongst all species. Phylogenetic analysis revealed clustering of DDX3 and DHX9 with corresponding proteins from other fish. Cellular localization of overexpressed DDX3 and DHX9 was performed using GFP-tagged proteins, and endogenous DDX3 localization was measured using immunocytochemistry. In the rainbow trout gonadal cell line, RTG-2, DHX9 localized mostly to the nucleus, while DDX3 was found mainly in the cytoplasm. Tissue distribution from healthy juvenile rainbow trout revealed ubiquitous constitutive expression, highest levels of DDX3 expression were seen in the liver and DHX9 levels were fairly consistent among all tissues tested. Stimulation of RTG-2 cells revealed that DDX3 and DHX9 transcripts were both significantly upregulated by treatment with the dsRNA molecule, poly I:C. A pull-down assay suggested both proteins were able to bind dsRNA. In addition to their roles in RNA metabolism, the conserved common domains found between the rainbow trout proteins and other species having defined antiviral roles, combined with the ability for the proteins to bind to dsRNA, suggest these proteins may play an important role in fish innate antiviral immunity. Future studies on both DDX3 and DHX9 function will contribute to a better understanding of teleost immunity.


Assuntos
RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/imunologia , Doenças dos Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/imunologia , Sequência de Aminoácidos , Animais , Linhagem Celular , RNA Helicases DEAD-box/química , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Perfilação da Expressão Gênica/veterinária , Filogenia , Poli I-C/farmacologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-31154023

RESUMO

Rare earth elements (REEs) are increasingly used in electronics industry and other areas of our economy and questions were raised about their impacts to the environment. The purpose of this study was to examine the lethal and sublethal toxicity of REEs in juvenile rainbow (Oncorhynchus mykiss) trout. The fish were exposed to increasing concentrations (0.064, 0.32, 1.6, 8 and 40 mg/L) of the following 7 REEs for 96 h at 15 °C: cerium (CeCl3), erbium (ErCl3), gadolinium (GdCl3), lanthanum (LaCl3), neodymium (NdCl3), samarium (SmCl3) and yttrium (YCl3). The mortality were determined and in the surviving fish, 10 target gene transcripts were measured in the liver to track changes in oxidative stress, DNA repair, tissue growth/proliferation, protein chaperoning, xenobiotic biotransformation and ammonia metabolism. The data revealed that Y, Sm, Er and Gd formed a distinct group based on toxicity (mortality) and gene expression changes. Electronegativity was significantly correlated (r = -0.8, p < 0.01) with the lethal concentration (LC50). Gene expression changes occurred at concentration circa 120 times lower than the LC50 and the following transcripts in protein chaperoning (heat shock proteins), DNA repair (growth arrest DNA Damage) and CYP1A1 gene expression involved in the metabolism of coplanar aromatic hydrocarbons were involved. In conclusion, the study revealed that the more electronegative REEs were the most toxic to trout juveniles and produced sublethal effects at concentrations 2 orders of magnitude lower than the lethal concentrations. The toxicity of REEs depends on the elements were toxicity involves specific pathways at the gene expression level.


Assuntos
Expressão Gênica/efeitos dos fármacos , Metais Terras Raras/toxicidade , Oncorhynchus mykiss/genética , Amônia/metabolismo , Animais , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Ecotoxicologia , Inativação Metabólica/efeitos dos fármacos , Inativação Metabólica/genética , Mortalidade , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Poluentes Químicos da Água/toxicidade , Xenobióticos/farmacocinética
15.
Dev Comp Immunol ; 99: 103403, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31150658

RESUMO

Mammalian TNFR1 and TNFR2 bind TNFα and TNFß, and provide key communication signals to a variety of cell types during development and immune responses that are crucial for cell survival, proliferation and apoptosis. In teleost fish TNFß is absent but TNFα has been expanded by the third whole genome duplication (3R WGD) and again by a 4R WGD in some lineages, leading to the four TNFα paralogues known in salmonids. Two paralogues for each of TNFR1 and TNFR2 have been cloned in rainbow trout in this study and are present in other salmonid genomes. Whilst the TNFR2 paralogues were generated via the 4R salmonid WGD, the TNFR1 paralogues arose from a local en bloc duplication. Functional diversification of TNFR paralogues was evidenced by differential gene expression and modulation, upstream ATGs affecting translation, ATTTA motifs in the 3'-UTR regulating mRNA stability, and post-translational modification by N-glycosylation. Trout TNFR are highly expressed in immune tissues/organs, and other tissues, in a gene- and tissue-specific manner. Furthermore, their expression is differentially modulated by PAMPs and cytokines in a cell type- and stimulant-specific manner. Such findings suggest an important role of the TNF/TNFR axis in the immune response and other physiological processes in fish.


Assuntos
Proteínas de Peixes/genética , Oncorhynchus mykiss/genética , Receptores Tipo II do Fator de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Evolução Molecular , Duplicação Gênica , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica , Genoma/genética , Interferons/farmacologia , Oncorhynchus mykiss/classificação , Oncorhynchus mykiss/imunologia , Padrões Moleculares Associados a Patógenos/farmacologia , Filogenia , Alinhamento de Sequência , Distribuição Tecidual
16.
Artigo em Inglês | MEDLINE | ID: mdl-31174158

RESUMO

Flavobacterium psychrophilum is the etiologic agent of rainbow trout fry syndrome (RTFS). This pathogen infects a wide variety of salmonid species during freshwater stages, causing significant losses in the aquaculture industry. Rainbow trout (Oncorhynchus mykiss) infected with F. psychrophilum, presents as the main external clinical sign ulcerative lesions and necrotic myositis in skeletal muscle. We previously reported the in vitro cytotoxic activity of F. psychrophilum on rainbow trout myoblast, however little is known about the molecular mechanisms underlying the in vivo pathogenesis in skeletal muscle. In this study, we examined the transcriptomic profiles of skeletal muscle tissue of rainbow trout intraperitoneally challenged with low infection dose of F. psychrophilum. Using high-throughput RNA-seq, we found that 233 transcripts were up-regulated, mostly associated to ubiquitin mediated proteolysis and apoptosis. Conversely, 189 transcripts were down-regulated, associated to skeletal muscle contraction. This molecular signature was consistent with creatine kinase activity in plasma and oxidative damage in skeletal muscle. Moreover, the increased caspase activity suggests as a whole skeletal muscle atrophy induced by F. psychrophilum. This study offers an integrative analysis of the skeletal muscle response to F. psychrophilum infection and reveals unknown aspects of its pathogenesis in rainbow trout.


Assuntos
Doenças dos Peixes/genética , Infecções por Flavobacteriaceae/veterinária , Flavobacterium/fisiologia , Oncorhynchus mykiss/genética , Transcriptoma , Animais , Aquicultura , Doenças dos Peixes/microbiologia , Doenças dos Peixes/patologia , Infecções por Flavobacteriaceae/genética , Infecções por Flavobacteriaceae/microbiologia , Infecções por Flavobacteriaceae/patologia , Interações Hospedeiro-Patógeno , Músculo Esquelético/metabolismo , Músculo Esquelético/microbiologia , Músculo Esquelético/patologia , Oncorhynchus mykiss/microbiologia
17.
PLoS One ; 14(6): e0218630, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31220151

RESUMO

Infection of rainbow trout with the parasitic ciliate Ichthyopthirius multifiliis induces differential responses in gills, skin and spleen. A controlled experimental infection was performed and expression of immune-relevant genes in skin, gills, and spleen were recorded by qPCR at day 1 and 8 after parasite exposure. Infection induced a marked reaction involving regulation of innate and adaptive immune genes in rainbow trout at day 8 post-infection. The expression level of a total of 22 out of 24 investigated genes was significantly higher in gills compared to skin reflecting the more sensitive and delicate structure of gills. Especially pro-inflammatory cytokines IL-6, IL-17 C1, regulatory cytokines IL-4/13A, IL-10, TGFß, complement factor C5, chemokines CK10, CK12, acute phase proteins (precerebellin, hepcidin) and immunoglobulins (IgM, IgT) displayed differential expression levels. The spleen, a central immune organ with no trace of the parasite, showed elevated expression of IgM, IgT, complement factor C5 and chemokine CK10 (compared to skin and gills directly exposed to the parasite), indicating an interaction between the infected surface sites and central immune organs. This communication could be mediated by chemokines CK10 and CK12 and cytokine IL-4/13A and may at least partly explain the establishment of a systemic response in rainbow trout against the parasite.


Assuntos
Infecções por Cilióforos/genética , Doenças dos Peixes/genética , Brânquias/imunologia , Oncorhynchus mykiss/genética , Pele/imunologia , Baço/imunologia , Proteínas da Fase Aguda/genética , Proteínas da Fase Aguda/metabolismo , Animais , Infecções por Cilióforos/imunologia , Infecções por Cilióforos/veterinária , Citocinas/genética , Citocinas/metabolismo , Doenças dos Peixes/imunologia , Doenças dos Peixes/parasitologia , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Imunoglobulinas/genética , Imunoglobulinas/metabolismo , Oncorhynchus mykiss/imunologia , Oncorhynchus mykiss/parasitologia , Especificidade de Órgãos
18.
Ecotoxicol Environ Saf ; 180: 616-623, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31132557

RESUMO

Pyroligneous acid (PA) is a by-product of bio-oil, which is obtained by pyrolysis of the wood. This product has been tested for use in several areas, such as agriculture, as a promising green herbicide; however, there are few scientific data regarding its environmental impacts. For this study, an ecotoxicity testing battery, composed of Daphnia magna acute toxicity test, Allium cepa test and in vitro Comet assay with the rainbow trout gonad-2 cell fish line (RTG-2) were used to evaluate the acute toxicity and genotoxicity of PA obtained from fast pyrolysis of eucalyptus wood fines. The PA presented acute toxicity to D. magna (microcrustacea) with EC50 of 26.12 mg/L, and inhibited the seed germination (EC50 5.556 g/L) and root development (EC50 3.436 g/L) of A. cepa (higher plant). No signs of genotoxicity (chromosomal aberrations and micronuclei in A. cepa and primary DNA lesions in RTG-2 cells) were detected to this product. The acute toxicity and absence of genotoxicity may relate to the molecules found in the PA, being the phenolic fraction the key chemical candidate responsible for the toxicity observed. In addition, daphnids seem to be more sensitivity to the toxicity of PA than higher plants based on their EC50 values. This first ecotoxicological evaluation of PA from fast pyrolysis pointed out the need of determining environmental exposure limits to promote the safer agriculture use of this product, avoiding impacts to living organisms.


Assuntos
Poluentes Ambientais/toxicidade , Herbicidas/toxicidade , Terpenos/toxicidade , Animais , Linhagem Celular , Dano ao DNA , Daphnia/efeitos dos fármacos , Oncorhynchus mykiss/genética , Cebolas/efeitos dos fármacos , Cebolas/genética , Pirólise , Testes de Toxicidade Aguda
19.
Fish Shellfish Immunol ; 90: 413-430, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31063803

RESUMO

Myxovirus resistance (Mx) proteins are interferon (IFN)-inducible Dynamin-like GTPases, which play an important role in antiviral immunity. Three Mx genes (Mx1-3) have been cloned previously in rainbow trout. In this study, an additional six Mx genes were cloned that reside in four chromosomal loci. Further bioinformatics analysis suggests the presence of three teleost Mx groups (TMG) each with a characteristic gene organisation. Salmonid Mx belong to TMG1 and TMG2. The increased salmonid Mx gene copies are due mainly to local gene duplications that happened before and after salmonid speciation, in a lineage/species specific manner. Trout Mx molecules have been diversified in the loop 1 and 4 regions, and in the nuclear localisation signal in loop 4. The trout Mx genes were shown to be differentially expressed in tissues, with high levels of expression of TMG1 (Mx1-4) in blood and TMG2 (Mx5-9) in intestine. The expression of the majority of the trout Mx genes was induced by poly IC in vitro and in vivo, and increased during development. In addition, induction by antiviral (IFN) and proinflammatory cytokines was studied, and showed that type I IFN, IFNγ and IL-1ß can induce Mx gene expression in an Mx gene-, cytokine- and cell line-dependent manner. These results show that salmonids possess a large number Mx genes as well as complex regulatory pathways, which may contribute to their success in an anadromous life style.


Assuntos
Doenças dos Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/imunologia , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/imunologia , Sequência de Aminoácidos , Animais , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Perfilação da Expressão Gênica/veterinária , Família Multigênica/imunologia , Proteínas de Resistência a Myxovirus/química , Filogenia , Poli I-C/farmacologia , Alinhamento de Sequência/veterinária
20.
Gen Comp Endocrinol ; 281: 30-40, 2019 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-31102580

RESUMO

Steelhead Trout (Oncorhynchus mykiss) display a varied life-history, including precocious male maturation at age-1 or age-2. In wild fish, precocious male maturation represents an important component of a diverse life-history portfolio. In hatchery programs, however, it is undesirable if rearing practices increase rates of early male maturation and reduce numbers of anadromous male adults. Our study aimed to develop endocrine and molecular markers for identifying males at early stages of maturation in the spring (prior to smolt release) and evaluated the potential use of these markers for quantifying early male maturation rates at a hatchery scale. In a laboratory study, Skookumchuck winter-run Steelhead Trout were reared at a high growth rate in order to increase the occurrence of precocious male maturation. Fish were lethally sub-sampled in February, prior to the time of smolt release; in May, at the time of smolt release; and in September, when 1+ age maturing males that would spawn the following spring were clearly identifiable based solely on gonadosomatic index (GSI). In February and May samples, we measured GSI, plasma 11-ketotestosterone (11KT), mRNAs for pituitary follicle stimulating hormone (fshb) and luteinizing hormone (lhb) beta subunits, and analyzed stage of spermatogenesis by testis histology. Additionally, in May, we measured testis anti-Müllerian hormone (amh) and insulin-like growth factor 3 (igf3) mRNA. Our primary goal was to evaluate the aforementioned maturation indices for their efficacy in forecasting the proportion of fish initiating early male maturation in the spring (approximately 1 year prior to spermiation), compared to the proportion that actually matured. Combining measures of GSI, plasma 11KT, and pituitary fshb and lhb mRNA expression provided a useful, but conservative, estimate of the proportion of males initiating maturation in the spring (21%) compared to the proportion that were ultimately destined to mature (37%) the following spring. These results suggest that maturation may be less synchronous than previously appreciated and some males may have initiated maturation after our census in May.


Assuntos
Biomarcadores/metabolismo , Sistema Endócrino/metabolismo , Oncorhynchus mykiss/genética , Estações do Ano , Maturidade Sexual/genética , Transcriptoma/genética , Animais , Tamanho Corporal , Regulação da Expressão Gênica , Modelos Lineares , Masculino , Oncorhynchus mykiss/anatomia & histologia , Oncorhynchus mykiss/sangue , Hipófise/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Testículo/citologia , Testículo/metabolismo , Testosterona/análogos & derivados , Testosterona/sangue
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