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1.
Bull Environ Contam Toxicol ; 105(5): 721-727, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33033868

RESUMO

The aim of this study was to determine the median lethal concentration (LC50-96h), effective concentration (EC50-96h), risk assessment, and development of Nile tilapia Oreochromis niloticus larvae submitted to florfenicol (FF) exposure. Fish (n = 147; 8.6 ± 0.6 mg; 7 fish/aquarium) were randomly distributed in 21 aquaria (1 L) and exposed to five concentrations of FF 58.73; 131.31; 198.96; 241.88 and 381.81 mg L-1 plus one control and a control with solvent, totalizing seven treatments and three replicates. The estimated median LC50-96h of FF for Nile tilapia larvae was 349.94 mg L-1. The EC50-96h of FF was 500 mg L-1 for weight reduction and was 1040 mg L-1 for length reduction. After the exposure period, final weight and length differed (p < 0.05) among treatments, showing the lowest biometric values ​​with the highest concentrations of FF. The pH and dissolved oxygen were altered (p < 0.05) during the experimental period. The FF high doses used to determine the LC 50 after 96 h negatively affected the development of the larvae. On the other hand, through risk assessment analysis this antibiotic can be classified as low toxicity to Nile tilapia larvae and show low environmental risk.


Assuntos
Ciclídeos/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Tianfenicol/análogos & derivados , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Desenvolvimento Embrionário/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Dose Letal Mediana , Distribuição Aleatória , Medição de Risco , Tianfenicol/toxicidade , Testes de Toxicidade Aguda
2.
Artigo em Inglês | MEDLINE | ID: mdl-32654587

RESUMO

The 17 alpha methyltestosterone (MT) hormone is fed to Oreochromis niloticus larvae in fish farms with the purpose of inducing sex reversal. The aim of this study was to evaluate the toxicity and sub-lethality of MT (99.9% purity) and cMT (a commercial MT with 90% purity) in zebrafish (Danio rerio) adults, where the animals were exposed to concentrations of 0, 4, 23, 139, 833 and 5000 µg/L for 96 hours. Genotoxicity was evaluated by micronucleus test (MN), nuclear abnormalities (NA) and comet assay. A low genotoxic potential of MT was showed, inducing micronucleus, nuclear abnormalities and DNA damage in Danio rerio, depending on the use of MT or cMT, gender and tested concentrations. In the sub-lethality trials, there was a basal difference in the activity of the enzymatic biochemical markers for males and females, while the Glutatione S transferase (GST) activity decreased in all analyzed tissues, and for males the enzymatic activity decreased only in the intestine. Results suggest that MT has a toxic potential to fish because it alters enzymatic metabolic pathways and may pose a risk to the ecosystems.


Assuntos
Androgênios/toxicidade , Dano ao DNA , Metiltestosterona/toxicidade , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/genética , Androgênios/farmacologia , Animais , Ciclídeos/crescimento & desenvolvimento , Ensaio Cometa , Relação Dose-Resposta a Droga , Ecossistema , Feminino , Pesqueiros , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Masculino , Metiltestosterona/farmacologia , Poluentes Químicos da Água/farmacologia
3.
Proc Natl Acad Sci U S A ; 117(32): 19321-19327, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32719137

RESUMO

Phenotypic plasticity, the ability of a single genotype to produce multiple phenotypes under different environmental conditions, is critical for the origins and maintenance of biodiversity; however, the genetic mechanisms underlying plasticity as well as how variation in those mechanisms can drive evolutionary change remain poorly understood. Here, we examine the cichlid feeding apparatus, an icon of both prodigious evolutionary divergence and adaptive phenotypic plasticity. We first provide a tissue-level mechanism for plasticity in craniofacial shape by measuring rates of bone deposition within functionally salient elements of the feeding apparatus in fishes forced to employ alternate foraging modes. We show that levels and patterns of phenotypic plasticity are distinct among closely related cichlid species, underscoring the evolutionary potential of this trait. Next, we demonstrate that hedgehog (Hh) signaling, which has been implicated in the evolutionary divergence of cichlid feeding architecture, is associated with environmentally induced rates of bone deposition. Finally, to demonstrate that Hh levels are the cause of the plastic response and not simply the consequence of producing more bone, we use transgenic zebrafish in which Hh levels could be experimentally manipulated under different foraging conditions. Notably, we find that the ability to modulate bone deposition rates in different environments is dampened when Hh levels are reduced, whereas the sensitivity of bone deposition to different mechanical demands increases with elevated Hh levels. These data advance a mechanistic understanding of phenotypic plasticity in the teleost feeding apparatus and in doing so contribute key insights into the origins of adaptive morphological radiations.


Assuntos
Ciclídeos/metabolismo , Proteínas de Peixes/metabolismo , Proteínas Hedgehog/metabolismo , Crânio/crescimento & desenvolvimento , Adaptação Fisiológica , Animais , Ciclídeos/genética , Ciclídeos/crescimento & desenvolvimento , Proteínas de Peixes/genética , Proteínas Hedgehog/genética , Transdução de Sinais , Crânio/metabolismo
4.
BMC Evol Biol ; 20(1): 69, 2020 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-32564776

RESUMO

BACKGROUND: East African lake cichlids are one of the most impressive examples of an adaptive radiation. Independently in Lake Victoria, Tanganyika, and Malawi, several hundreds of species arose within the last 10 million to 100,000 years. Whereas most analyses in cichlids focused on nucleotide substitutions across species to investigate the genetic bases of this explosive radiation, to date, no study has investigated the contribution of structural variants (SVs) in the evolution of adaptive traits across the three Great Lakes of East Africa. RESULTS: Here, we annotate and characterize the repertoires and evolutionary potential of different SV classes (deletion, duplication, inversion, insertions and translocations) in four cichlid species: Haplochromis burtoni, Metriaclima zebra, Neolamprologus brichardi and Pundamilia nyererei. We investigate the patterns of gain and loss evolution for each SV type, enabling the identification of lineage specific events. Both deletions and inversions show a significant overlap with SINE elements, while inversions additionally show a limited, but significant association with DNA transposons. Inverted regions are enriched for genes regulating behaviour, or involved in skeletal and visual system development. We also find that duplicated regions show enrichment for genes associated with "antigen processing and presentation" and other immune related categories. Our pipeline and results were further tested by PCR validation of selected deletions and inversions, which confirmed respectively 7 out of 10 and 6 out of 9 events. CONCLUSIONS: Altogether, we provide the first comprehensive overview of rearrangement evolution in East African cichlids, and some important insights into their likely contribution to adaptation.


Assuntos
Ciclídeos/genética , Variação Genética , Crescimento e Desenvolvimento/genética , Imunidade/genética , Animais , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/imunologia , Elementos de DNA Transponíveis/genética , Evolução Molecular , Fenótipo
5.
Anim Genet ; 51(4): 611-616, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32378756

RESUMO

The Nile tilapia (Oreochromis niloticus) is a prominent farmed fish in aquaculture worldwide. Crossbreeding has recently been carried out between the Red-Stirling and the wt Chitralada strains of Nile tilapia, producing a heterotic hybrid (7/8 Chitralada and 1/8 Red-Stirling) that combines the superior growth performance of the Chitralada with the reddish coloration of the Red-Stirling strain. While classical selective breeding and crossbreeding strategies are well known, the molecular mechanisms underlying the phenotypic expression of economically advantageous traits in tilapia remain largely unknown. Molecular investigations have shown that variable expression of growth hormone (gh), insulin-like growth factors (igf1 and 2) and somatolactin (smtla) - components of the growth hormone/insulin-like growth factor (GH/IGF) axis - and myostatin (mstn) genes can affect traits of economic relevance in farmed animals. The aim of this study was to assess and compare the gene expression signature among Chitralada, Red-Stirling and their backcross hybrid in order to gain insights into the effects of introgressive breeding in modulation of the GH/IGF axis. Gene expression analyses in distinct tissues showed that most genes of the GH/IGF axis were up-regulated and mstn was down-regulated in backcross animals in comparison with Red-Stirling and Chitralada animals. These gene expression profiles revealed that backcross animals displayed a distinctive expression signature, which attests to the effectiveness of the introgressive breeding technique. Our findings also suggest that the GH/IGF axis and mstn genes might be candidate markers for fish performance and prove useful within genetic improvement programs aimed at the production of superior-quality tilapia strains using introgressive breeding.


Assuntos
Ciclídeos/genética , Introgressão Genética , Transcriptoma , Animais , Cruzamento , Ciclídeos/crescimento & desenvolvimento , Hibridização Genética
6.
Aquat Toxicol ; 224: 105494, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32422488

RESUMO

Little is known about the impacts of dietary exposure to inorganic mercury (Hg) for a long duration on the health indicators, growth, and disease resistance in Oreochromis niloticus. Accordingly, the current study was designed to assess the effects of Hg contaminated diets on blood biochemistry, growth, chemical composition, Hg bioaccumulation in the tissues, histopathology of liver and head kidneys, and disease resistance to Aeromonas hydrophila of O. niloticus. Also, the efficiency of citronella oil, geranium oil (GO), curcumin (CUR), Bacillus toyonensis (BT), and Bacillus subtilis (BS) as dietary supplements on reversing the negative impacts of Hg were assessed. A total of 240 tilapia fingerlings were assigned to eight dietary treatments fed on the basal diet (G1), G1 diet contaminated with 50 ppm Hg (G2), whereas the other groups fed the G2 diet and enriched with 400 mg CO (G3), 400 mg GO (G4), 200 mg CUR (G5), 7 × 107 cells BT (G6), 7 × 107 cells BS (G7), and 7 × 107 BT + BS/ kg diet (G8) for 16 weeks. The obtained results showed that fish fed on the G2 diet had significantly impaired growth performance indicators, blood parameters, and resistance to bacterial infection compared with fish in the control group. Additionally, distinct pathological perturbations in liver and head kidneys were observed. In contrast, fish groups G3 to G8 had a significant enhancement in the growth performance, Hg bioaccumulation in fish tissues, blood biochemistry, and resistance against A. hydrophila infection compared with fish in the G2 group. Maximum improvement was recorded in G5, G6, and G8. Conclusively, from both health and an economic point of view, these results suggested that several benefits might be gained by adding these additives, especially CUR, BT, and BT + BS, on growth enhancement and ameliorating Hg negative impacts in O. niloticus.


Assuntos
Ração Animal/análise , Bioacumulação , Ciclídeos/crescimento & desenvolvimento , Resistência à Doença/efeitos dos fármacos , Doenças dos Peixes/prevenção & controle , Infecções por Bactérias Gram-Negativas/veterinária , Mercúrio/toxicidade , Poluentes Químicos da Água/toxicidade , Aeromonas hydrophila/patogenicidade , Animais , Ciclídeos/imunologia , Ciclídeos/microbiologia , Dieta , Suplementos Nutricionais , Resistência à Doença/imunologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/microbiologia , Rim Cefálico/efeitos dos fármacos , Rim Cefálico/metabolismo , Rim Cefálico/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo
7.
Trop Anim Health Prod ; 52(5): 2443-2450, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32318973

RESUMO

The study aimed to evaluate heat-treated bean residue meal (Phaseolus vulgaris)-BRM-as an alternative protein source in diets for Nile tilapia fish. A completely randomized design was used, totaling four (n = 4) dietary treatments: diet without BRM (CON), raw BRM (RBRM) and heat-treated BRM at 100 °C for 15 min (BRM15), and 30 min (BRM30) before inclusion in diets. Nile tilapia fingerlings (1.3 g initial weight) were hand-fed the experimental diets for 66 days, divided equally into three meals per day. Performance parameters, body composition, nutrient retention, and physical characteristics of diets were evaluated. Growth and feed conversion were lower (P < 0.05) in fish fed BRM. Protein productive value was higher (P < 0.05) in fish fed CON diet than in fish receiving BRM. However, 30 min heat treatment of BRM increased (P < 0.05) protein retention in fish. Fish fed BRM30 also had higher protein content (P < 0.05) and reduced body lipid content (P < 0.05) than those fed CON diet. The physical characteristics (durability, dry matter leaching, waterproof time, and water stability time) were significantly improved (P < 0.05) in the BRM30 diet compared with other dietary treatments. The dietary inclusion of BRM at the level of 15% is not recommended for tilapia due to low growth performance and feed efficiency, regardless of preheating treatment. However, research on longer heat treatment time is needed due to the improvements observed in nutrient retention and physical characteristics of diets.


Assuntos
Ração Animal/análise , Ciclídeos/fisiologia , Dieta/veterinária , Phaseolus/química , Animais , Composição Corporal , Ciclídeos/crescimento & desenvolvimento , Temperatura Alta , Proteínas de Vegetais Comestíveis , Distribuição Aleatória
8.
Environ Toxicol Chem ; 39(7): 1409-1420, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32323358

RESUMO

Blooms of toxin-producing cyanobacteria have been more frequent and lasting because of the eutrophication of freshwater ecosystems, including those used for aquaculture. The aim of the present study was to investigate the effects of chronic exposure to a saxitoxin-producing strain of Raphidiopsis (Cylindrospermopsis) raciborskii on the performance of Nile tilapia (Oreochromis niloticus) fingerlings over a 60-d period. The fingerlings were cultivated under the following conditions: 1) water without cyanobacterium (WATER), 2) R. raciborskii in ASM-1 culture medium (CYANO), and 3) ASM-1 culture medium without cyanobacterium (ASM). Exposure to the CYANO treatment led to a significant increase in the mortality rate (p < 0.05) and a significant reduction in growth (p < 0.05) compared to fingerlings submitted to the ASM and WATER treatments, in which similar survival and growth were found (p > 0.05). Saxitoxin toxicity was dependent on the weight of the fingerling (p < 0.05), with maximum mortality caused by the ingestion of 13.66 µg saxitoxin equivalent L-1 g-1 . The present results clearly show the harm caused by saxitoxins to the production of Nile tilapia fingerlings in the early growth phase. These findings underscore the importance of maintaining adequate water quality in aquaculture activities to minimize the risk of saxitoxin-producing cyanobacterial blooms and avoid economic losses among producers. Environ Toxicol Chem 2020;39:1409-1420. © 2020 SETAC.


Assuntos
Ciclídeos/crescimento & desenvolvimento , Ciclídeos/microbiologia , Cylindrospermopsis/fisiologia , Exposição Ambiental , Saxitoxina/biossíntese , Animais , Biomassa , Peso Corporal , Comportamento Alimentar , Masculino , Qualidade da Água
9.
J Therm Biol ; 88: 102500, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32125987

RESUMO

The present study investigated the effects of sodium butyrate (SB) on the growth performance, histomorphology, immune response, and stress related markers of Nile tilapia subjected to heat stress. SB was incorporated at 0, 0.5, 1, 1.5, and 2 g per kg diet and fed to fish for 8 weeks. The obtained results revealed significantly improved growth performance with a decreased feed conversion ratio in the fish fed SB (P < 0.05). In the anterior, middle, and distal parts of the intestine, villus length and width and internal villi distance as well as the number of goblet cells were increased in the fish fed SB (P < 0.05). The blood total protein, hemoglobin, and white and red blood cell counts showed a significant quadratic influence (P < 0.05). The survival rate for Nile tilapia exposed to heat stress for 48 h revealed that the SB fed groups had noticeably higher survival rates. Dietary SB significantly increased the phagocytic index and lysozyme and phagocytic activities both before and after heat stress (P < 0.05). After heat stress, blood glucose decreased significantly with SB feeding at 0.5, 1, or 1.5 g per kg diet, while cortisol was reduced in fish fed 1.5 or 2 g per kg diet (P < 0.05). Additionally, in fish fed SB, superoxide dismutase (SOD), catalase, and glutathione peroxidase activities were significantly increased both before and after heat stress, while malondialdehyde was decreased by SB feeding (P < 0.05). Liver heat shock protein 70 and SOD gene expression were significantly upregulated in fish fed on SB at 1 g per kg diet (P < 0.05). Thus, supplementation with SB at 1-2 g per kg diet can be used effectively in tilapia diets for improving growth, feed efficiency, and immune response as well as for tolerance to heat stress.


Assuntos
Ácido Butírico/farmacologia , Ciclídeos , Resposta ao Choque Térmico/efeitos dos fármacos , Sódio na Dieta/farmacologia , Ração Animal , Animais , Biomarcadores/metabolismo , Glicemia/análise , Catalase/metabolismo , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/imunologia , Ciclídeos/metabolismo , Dieta/veterinária , Proteínas de Peixes/metabolismo , Glutationa Peroxidase/metabolismo , Proteínas de Choque Térmico HSP70/genética , Intestinos/crescimento & desenvolvimento , Malondialdeído/metabolismo , Muramidase/metabolismo , Fagocitose/efeitos dos fármacos , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
10.
Gene ; 742: 144538, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32184168

RESUMO

Lysosomal desialylation is the initial step in the degradation of sialo-glycopeptides that is essential for regenerating sialo-glycoconjugates. Neu1 sialidase is the enzyme responsible for the removal of sialic acid in the mammalian lysosome. Although Neu1 sialidases are conserved in fish similar to mammals, their physiological functions remain to be fully understood. Nile tilapia (Oreochromis niloticus) is known to possess two putative Neu1 sialidases (Neu1a and Neu1b) in the genome that may have arisen by gene duplication (specifically in cichlidae family members). This suggests that understanding the Neu1 sialidase in fish, particularly cichlids, could provide insights into the (novel) physiological functions of these genes. Moreover, characterization of the tilapia Neu1 sialidase is paramount to ensure clarity of the desialylation reaction performed by the fish sialidases (like the characterized tilapia sialidases Neu3 and Neu4). Therefore, this study focused on the characterization of the tilapia Neu1 sialidases. Neu1b exhibited narrow substrate specificity when compared with Neu1a, whereas the properties of these two Neu1 sialidases, such as cathepsin A-induced activation, optimal pH, and lysosomal localization, were conserved. Neu1a mRNA levels were detected in various tissues of tilapia as compared to the mRNA levels of Neu1b. Although the cloned construct of Neu1b contained an extra exon unlike tilapia Neu1a, the exon did not affect the enzymatic properties of Neu1b. This study suggests that tilapia Neu1a profiles were highly conserved with other vertebrate Neu1 isoforms, while Neu1b probably evolved independently in other members of the cichlidae family. Moreover, the expression of sialidase genes (neu1a, neu1b, neu3a, and neu4) were determined in various stages of tilapia embryogenesis using real-time PCR; sialidase gene expression is reported to be drastically and individually altered during embryogenesis in Japanese medaka (Oryzias latipes). The mRNA levels of neu1a drastically increased between 72 and 84 hpf and mildly decreased from 84 to 144 hpf. In contrast, the transcript levels of neu1b did not change between 84 and 144 hpf and the expression of neu3a gradually increased between 84 and 120 hpf and drastically decreased at 144 hpf. The highest level of the neu4 transcripts was detected at 84 hpf. These expression patterns were different from those in Japanese medaka, possibly due to the different developmental program found in the tilapia embryo accompanied with the unique profiles of the tilapia sialidases.


Assuntos
Ciclídeos/metabolismo , Proteínas de Peixes/metabolismo , Neuraminidase/metabolismo , Animais , Ciclídeos/genética , Ciclídeos/crescimento & desenvolvimento , Clonagem Molecular , Evolução Molecular , Feminino , Proteínas de Peixes/química , Proteínas de Peixes/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Neuraminidase/química , Neuraminidase/genética , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Especificidade por Substrato/genética
11.
Mar Biotechnol (NY) ; 22(3): 367-379, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32088770

RESUMO

Artificially high temperatures during critical thermosensitive periods (TSPs) can induce the sex reversal of Nile tilapia (Oreochromis niloticus) females into pseudomales; Nile tilapia is a GSD + TE (genotypic plus temperature effects) fish species. Previous studies have shown that water temperature affects the expression levels of many genes in the gonad or brain in various teleost species. However, few studies on the effect of temperature at the whole-gonad transcriptomic level in the early stage of sex differentiation have been reported in fish species exhibiting GSD + TE. In this study, RNA-Seq was performed to characterize the transcriptomic profile and identify genes exhibiting temperature- and sex-biased expressions in the Nile tilapia gonad at 21 dpf. A total of 42 genes were found to be associated with both high-temperature treatment and sex development, as the expression levels of these genes differed in both FC (female control) vs MC (male control) and FC vs FT (high temperature-treated females in the TSP). Among these genes, the transcriptional alterations of many male sex determination and differentiation genes, such as Dmrt1, Gsdf, and the DNA damage-inducible protein GADD45 alpha, suggested that the male pathway is initiated after high-temperature treatment and that its initiation may play a role in high temperature-induced masculinization in Nile tilapia. The qRT-PCR validation results for thirteen differentially expressed genes showed that the Pearson's correlation of the log10 fold change values between the qPCR and RNA-Seq results was 0.70 (p < 0.001), indicating the accuracy and reliability of the RNA-Seq results. Our study provides insights into how high-temperature treatment induces the sex reversal of Nile tilapia females.


Assuntos
Ciclídeos/genética , Temperatura Alta , Processos de Determinação Sexual/genética , Animais , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genótipo , Gônadas/crescimento & desenvolvimento , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA
12.
PLoS One ; 15(1): e0227690, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31999691

RESUMO

Fish oogenesis is characterised by a massive growth of oocytes each reproductive season. This growth requires the stockpiling of certain molecules, such as ribosomal RNAs to assist the rapid ribosomal assembly and protein synthesis required to allow developmental processes in the newly formed embryo. Massive 5S rRNA expression in oocytes, facilitated by transcription factor 3A (Gtf3a), serves as marker of intersex condition in fish exposed to xenoestrogens. Our present work on Gtf3a gene evolution has been analysed in silico in teleost genomes and functionally in the case of the zebrafish Danio rerio. Synteny-analysis of fish genomes has allowed the identification of two gtf3a paralog genes, probably emerged from the teleost specific genome duplication event. Functional analyses demonstrated that gtf3ab has evolved as a gene specially transcribed in oocytes as observed in Danio rerio, and also in Oreochromis niloticus. Instead, gtf3aa was observed to be ubiquitously expressed. In addition, in zebrafish embryos gtf3aa transcription began with the activation of the zygotic genome (~8 hpf), while gtf3ab transcription began only at the onset of oogenesis. Under exposure to 100 ng/L 17ß-estradiol, fully feminised 61 dpf zebrafish showed transcription of ovarian gtf3ab, while masculinised (100 ng/L 17α-methyltestosterone treated) zebrafish only transcribed gtf3aa. Sex related transcription of gtf3ab coincided with that of cyp19a1a being opposite to that of amh and dmrt1. Such sex dimorphic pattern of gtf3ab transcription was not observed earlier in larvae that had not yet shown any signs of gonad formation after 26 days of oestradiol exposure. Thus, gtf3ab transcription is a consequence of oocyte differentiation and not a direct result of estrogen exposure, and could constitute a useful marker of gonad feminisation and intersex condition.


Assuntos
Ovário/metabolismo , Fator de Transcrição TFIIIA/genética , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Ciclídeos/genética , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/metabolismo , Transtornos do Desenvolvimento Sexual/genética , Evolução Molecular , Feminino , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Duplicação Gênica , Masculino , Oogênese/genética , Filogenia , Caracteres Sexuais , Diferenciação Sexual/genética , Sintenia , Fator de Transcrição TFIIIA/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
13.
Genet Sel Evol ; 52(1): 1, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941436

RESUMO

BACKGROUND: The availability of both pedigree and genomic sources of information for animal breeding and genetics has created new challenges in understanding how they can be best used and interpreted. This study estimated genetic variance components based on genomic information and compared these to the variance components estimated from pedigree alone in a population generated to estimate non-additive genetic variance. Furthermore, the study examined the impact of the assumptions of Hardy-Weinberg equilibrium (HWE) on estimates of genetic variance components. For the first time, the magnitude of inbreeding depression for important commercial traits in Nile tilapia was estimated by using genomic data. RESULTS: The study estimated the non-additive genetic variance in a Nile tilapia population of full-sib families and, when present, it was almost entirely represented by additive-by-additive epistatic variance, although in pedigree studies this non-additive variance is commonly assumed to arise from dominance. For body depth (BD) and body weight at harvest (BWH), the proportion of additive-by-additive epistatic to phenotypic variance was estimated to be 0.15 and 0.17 using genomic data (P < 0.05). In addition, with genomic data, the maternal variance (P < 0.05) for BD, BWH, body length (BL) and fillet weight (FW) explained approximately 10% of the phenotypic variances, which was comparable to pedigree-based estimates. The study also showed the detrimental effects of inbreeding on commercial traits of tilapia, which was estimated to reduce trait values by 1.1, 0.9, 0.4 and 0.3% per 1% increase in the individual homozygosity for FW, BWH, BD and BL, respectively. The presence of inbreeding depression but lack of dominance variance was consistent with an infinitesimal dominance model for the traits. CONCLUSIONS: The benefit of including non-additive genetic effects for genetic evaluations in tilapia breeding schemes is not evident from these findings, but the observed inbreeding depression points to a role for reciprocal recurrent selection. Commercially, this conclusion will depend on the scheme's operational costs and resources. The creation of maternal lines in Tilapia breeding schemes may be a possibility if the variation associated with maternal effects is heritable.


Assuntos
Ciclídeos/genética , Genoma , Carne/análise , Animais , Peso Corporal , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/fisiologia , Feminino , Endogamia , Depressão por Endogamia , Masculino , Herança Materna , Modelos Genéticos , Músculo Esquelético/química , Linhagem , Fenótipo , Característica Quantitativa Herdável
14.
Aquat Toxicol ; 220: 105406, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31945653

RESUMO

Currently, feed adulteration and contamination with melamine (MEL) are considered one of the serious issues in the aquatic industry. With the limited studies of MEL exposure alone in fish, its adverse impacts on fish cannot be evaluated well. Accordingly, this study aimed to investigate the effects of MEL containing diets on the immune response, disease resistance to Aeromonas hydrophila, growth performance, chemical composition, immune-related genes expression, and histopathology of both spleen and head kidneys. Also, the efficacy of curcumin (CUR) dietary supplementation to alleviate MEL negative impacts were evaluated. A total of 180 apparently healthy Oreochromis niloticus (O. niloticus) were divided into four groups with three replicates fed the basal diet only, basal diet fortified with 200 mg/kg CUR, basal diet containing 1 % MEL, or a basal diet containing CUR + MEL. The results displayed that MEL significantly reduced growth performance indices and body crude lipid contents. Anemic, leukopenic, lymphocytopenic, heterocytopenic, esonipenic, hypoproteinemic and hypoalbuminic conditions were apparent. Moreover, depleted immune and antioxidant indicators including lysozyme activity, nitric oxide, immunoglobulin M, complement 3, glutathione peroxidase, and superoxide dismutase enzyme activity were recorded. Also, MEL reduced the disease resistance of O. niloticus to bacterial infection. Furthermore, MEL induced downregulation of mRNA levels of interleukin 1ß and tumor necrosis factor α in the spleen together with obvious pathological perturbations in both spleen and head kidneys. The CUR addition resulted in a significant enhancement in most indices. These results may conclude that MEL could alter both innate and adaptive immune responses via the negative transcriptional effect on immune-related genes together with the oxidative damage of the immune organs. Furthermore, CUR dietary supplements could be advantageous for mitigating MEL negative impacts, thus offering a favorable aquafeed additive for O. niloticus.


Assuntos
Ração Animal/análise , Ciclídeos , Curcumina/farmacologia , Citocinas/biossíntese , Resistência à Doença/efeitos dos fármacos , Contaminação de Alimentos/análise , Triazinas/toxicidade , Aeromonas hydrophila/crescimento & desenvolvimento , Animais , Antioxidantes/metabolismo , Ciclídeos/sangue , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/metabolismo , Suplementos Nutricionais , Resistência à Doença/imunologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Doenças dos Peixes/prevenção & controle , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/prevenção & controle , Rim Cefálico/efeitos dos fármacos , Rim Cefálico/metabolismo , Estresse Oxidativo/efeitos dos fármacos
15.
Bull Environ Contam Toxicol ; 104(2): 180-184, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31894370

RESUMO

Melano-macrophage centers (MMCs) are nodular clusters of pigmented macrophages, implicated in homeostasis and destruction and recycling of endogenous and exogenous material. They can increase in size and/or frequency under environmental stress resulting in immunohistological biomarkers of water quality. Fluoxetine (FLX), a commonly prescribed antidepressant, can cause neuroendocrine, behavioral and reproductive alterations in teleost fish. In the present study, we analyzed the effects of a 2-week 50 µg/L FLX exposure on MMCs in histological sections of spleen and head-kidney (HK) of the cichlid fish Cichlasoma dimerus. In the spleen, FLX caused an increase in the area and a decrease in the number of MMCs. An increase in the proportion of the HK occupied by MMCs was observed in FLX-exposed fish, due to an increase in their number but not their area. The deposition rate of MMCs varies according to the hemolymphopoietic organ and would be the result of a differential response to FLX on homeostatic functions (elimination of cellular debris, iron processing and immune response).


Assuntos
Antidepressivos/toxicidade , Fluoxetina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/metabolismo , Ciclídeos/fisiologia , Água Doce/química , Rim Cefálico/efeitos dos fármacos , Rim Cefálico/metabolismo , Imuno-Histoquímica , Baço/efeitos dos fármacos , Baço/metabolismo
16.
Fish Shellfish Immunol ; 98: 193-200, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923565

RESUMO

The present study addressed the possible effects of fishwort (Houttuynia cordata) powder (FWP) on Nile tilapia's skin mucus parameter, serum immune response, and growth performance. Three hundred twenty tilapia fingerlings (average weight of 39.06 ± 0.16 g) were divided into four treatments and fed four levels of FWP; 0, 5, 10, and 20 g kg-1 for 72 days. Completed randomised design of the four replications was applied and revealed that fish fed FWP significantly improved skin mucus lysozyme activity (SMLA). The highest value (P < 0.05) was recorded in fish fed 10 g kg-1 FWP. However, no significant difference in SMLA was observed by feeding the fish 5 and 20 g kg-1 FWP. Significant (P < 0.05) enhanced skin mucus peroxidase activity (SMPA) was observed in fish fed 10 g kg-1 FWP, but no significant difference in SMPA was detected between FWP supplemented diets (5 and 20 g kg-1 FWP) and the control group. Regarding serum immunity, dietary administration of FWP showed significantly (P < 0.05) improved serum lysozyme, peroxidase, alternative complement (ACH50), and phagocytosis vs. the control. The highest values of serum immunity (P < 0.05) were recorded in fish fed 10 g kg-1 FWP. However, no significance in respiratory burst activity was observed. Similarly, no significant difference in growth performance, feed conversion ratio, and survival rate was observed in fish fed FWP compared to the control. In summary, diets supplemented with FWP (10 g kg-1) increased the serum and mucosal immunity; however, no FWP supplementations had effects on Nile tilapia growth and survival rate.


Assuntos
Ciclídeos/imunologia , Suplementos Nutricionais , Houttuynia/química , Pele/imunologia , Ração Animal/análise , Animais , Aquicultura , Ciclídeos/crescimento & desenvolvimento , Dieta/veterinária , Imunidade Humoral , Imunidade nas Mucosas
17.
World J Microbiol Biotechnol ; 36(1): 16, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31897642

RESUMO

Earthworms are used as an alternative protein source in aquaculture. These organisms serve as an ideal and favorable site for bacterial growth and activity. Hence, in our present study, we isolated and screened potential probiotic bacteria from African nightcrawler (Eudrilus eugeniae). Among 45 bacterial isolates, four (ANSCI9, BFAR9, RM3, and RM10) were selected based on their hydrophobicity, hydrolytic enzyme production, pH and fish bile tolerance, aggregation, and antimicrobial properties. The selected isolates showed good hydrophobicity (≥ 30%) and enzyme production (≥ 10 mm clearing zones), tolerance to pH and fish bile, and inhibitory properties against pathogenic microorganisms. The isolates were identified as Bacillus sp. RM3 (MH919306), Bacillus sp. RM10 (MH919308), Bacillus sp. ANSCI9 (MH919310) and Bacillus sp. BFAR9 (MH919302). These isolates were individually incorporated in the diets of Nile tilapia (Oreochromis niloticus) fingerlings for 14 days to assess their biosafety. The results showed that the survival rates in all treated groups (98.75 ± 2.5 to 100.00 ± 0.0%) were not significantly different (P < 0.05) from the control group (commercial diet) (96.25 ± 2.5%), suggesting that isolates have no adverse effect on the host. This study revealed the presence of potential probiotic microorganisms in E. eugeniae that are beneficial to the aquaculture industry.


Assuntos
Bacillus/classificação , Ciclídeos/crescimento & desenvolvimento , Oligoquetos/microbiologia , Animais , Aquicultura , Bacillus/genética , Bacillus/isolamento & purificação , Bile/microbiologia , Concentração de Íons de Hidrogênio , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Filogenia , Probióticos/farmacologia
18.
J Endocrinol ; 244(3): 487-499, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31910154

RESUMO

The impacts of androgens and glucocorticoids on spermatogenesis have intrigued scientists for decades. 11ß-hydroxylase, encoded by cyp11c1, is the key enzyme involved in the synthesis of 11-ketotestosterone and cortisol, the major androgen and glucocorticoid in fish, respectively. In the present study, a Cyp11c1 antibody was produced. Western blot and immunohistochemistry showed that Cyp11c1 was predominantly expressed in the testicular Leydig cells and head kidney interrenal cells. A mutant line of cyp11c1 was established by CRISPR/Cas9. Homozygous mutation of cyp11c1 caused a sharp decrease of serum cortisol and 11-ketotestosterone, and a delay in spermatogenesis which could be rescued by exogenous 11-ketotestosterone or testosterone, but not cortisol treatment. Intriguingly, this spermatogenesis restored spontaneously, indicating compensatory effects of other androgenic steroids. In addition, loss of Cyp11c1 led to undersized testes with a smaller efferent duct and disordered spermatogenic cysts in adult males. However, a small amount of viable sperm was produced. Taken together, our results demonstrate that cyp11c1 is important for testicular development, especially for the initiation and proper progression of spermatogenesis. 11-ketotestosterone is the most efficient androgen in tilapia.


Assuntos
Ciclídeos/metabolismo , Espermatogênese , Espermatozoides/enzimologia , Esteroide 11-beta-Hidroxilase/genética , Testículo/crescimento & desenvolvimento , Testosterona/análogos & derivados , Animais , Ciclídeos/genética , Ciclídeos/crescimento & desenvolvimento , Feminino , Técnicas de Inativação de Genes , Masculino , Espermatozoides/citologia , Espermatozoides/metabolismo , Esteroide 11-beta-Hidroxilase/metabolismo , Testículo/citologia , Testículo/enzimologia , Testículo/metabolismo , Testosterona/metabolismo
19.
Fish Shellfish Immunol ; 97: 165-172, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31846780

RESUMO

The present study aimed at evaluating the possible effects of Leucas aspera as immunostimulant on mucosal and serum immunity, as well as on growth and resistance against Streptococcus agalactiae infection in Nile tilapia (Oreochromis niloticus) fingerlings. In a 45 days trial, fish were fed experimental diets containing L. aspera 0 g kg-1 (Diet 1- control), 1 g kg-1 (Diet 2), 2 g kg-1(Diet 3), 4 g kg-1 (Diet 4) and 8 g kg-1 (Diet 5). The results revealed a significant increase in the specific growth rate (SGR), weight gain (WG), and final weight (FW) in fish fed diet 3 (2 g kg-1) of L. aspera compared to the control and other supplemented groups (P < 0.05). Also, feeding on diet 3 (2 g kg-1) of L. aspera enriched diet significantly (P < 0.05) increased lysozyme activities in the serum and mucus, serum peroxidase and phagocytosis activity. However, significant (P < 0.05) increase in mucus peroxidase activity was reported in fish fed diet 4 (4 g kg-1) and diet 5 (8 g kg-1) of L. aspera, whereas significantly higher (P < 0.05) alternative complement activity was reported in fish fed diet 2 (1 g kg-1) of L. aspera. At the end of the experiment, nine fish per replication were selected for a challenge test against S. agalactiae. The dietary supplementation of L. aspera significantly reduced the mortality rate and increased the resistance of Nile tilapia following by challenge with S. agalactiae. The highest post challenge survival of 100% was observed in tilapia fed diet 5 (8 g kg-1) following by 92.6% of RPS in fish fed diet 4 (4 g kg-1) and 88.9% in diet 3 (2 g kg-1), 77.8% in diet 2 (1 g kg-1) and 74.1% in diet 1(0 g kg-1).


Assuntos
Ciclídeos/crescimento & desenvolvimento , Ciclídeos/imunologia , Resistência à Doença , Imunidade Inata , Lamiaceae , Infecções Estreptocócicas/veterinária , Ração Animal/análise , Animais , Ciclídeos/microbiologia , Suplementos Nutricionais/análise , Membrana Mucosa/imunologia , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae/imunologia
20.
Fish Shellfish Immunol ; 97: 509-514, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31877360

RESUMO

In this study, the effect of Lycium barbarum polysaccharides (LBP) on immunological parameters, apoptosis, and growth performance of Nile tilapia (Oreochromis niloticus) was investigated. Dietary supplementation with LBP significantly increased complement 3 (C3) activity and promoted interleukin IL-1ß gene expression in spleen tissue, significantly reduced apoptosis in spleen tissue, increased the specific growth rate (SGR), relative length gain (LG), and relative weight gain (WG) of Nile tilapia. However, dietary supplementation with LBP did not have a significant effect on serum alkaline phosphatase (AKP), malondialdehyde (MDA), and superoxide dismutase (SOD), blood constituents, apoptosis, or gene expression of IL-1ß in liver tissue. Overall, the results showed that dietary supplementation with LBP increased the nonspecific immunity of Nile tilapia and reduced the apoptosis rate to promote growth and development. Thus, LBP has potential for use as a new immunostimulant in aquaculture.


Assuntos
Apoptose/efeitos dos fármacos , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/imunologia , Suplementos Nutricionais , Medicamentos de Ervas Chinesas/administração & dosagem , Ração Animal , Animais , Aquicultura , Complemento C3/imunologia , Doenças dos Peixes/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia
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