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1.
Aquat Toxicol ; 220: 105403, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31927064

RESUMO

Transgenic fish are powerful models that can provide mechanistic information regarding the endocrine activity of test chemicals. In this study, our objective was to use a newly developed transgenic zebrafish line expressing eGFP under the control of the cyp19a1a promoter in the OECD Fish Short Term Reproduction Assay (TG 229) to provide additional mechanistic information on tested substances. For this purpose, we exposed adult transgenic zebrafish to a reference substance of the TG 229, i.e. prochloraz (PCZ; 1.7, 17.2 and 172.6 µg/L). In addition to "classical" endpoints used in the TG 229 (reproductive outputs, vitellogenin), the fluorescence intensity of the ovaries was monitored at 4 different times of exposure using in vivo imaging. Our data revealed that 172.6 µg/L PCZ significantly decreased the number of eggs laid per female per day and the concentrations of vitellogenin in females, reflecting the decreasing E2 synthesis due to the inhibition of the ovarian aromatase activities. At 7 and 14 days, GFP intensities in ovaries were similar over the treatment groups but significantly increased after 21 days at 17.2 and 172.6 µg/L. A similar profile was observed for the endogenous cyp19a1a expression measured by qPCR thereby confirming the reliability of the GFP measurement for assessing aromatase gene expression. The overexpression of the cyp19a1a gene likely reflects a compensatory response to the inhibitory action of PCZ on aromatase enzymatic activities. Overall, this study illustrates the feasibility of using the cyp19a1a-eGFP transgenic line for assessing the effect of PCZ in an OECD test guideline while providing complementary information on the time- and concentration-dependent effects of the compound, without disturbing reproduction of fish. The acquisition of this additional mechanistic information on a key target gene through in vivo fluorescence imaging of the ovaries was realized without increasing the number of individuals.


Assuntos
Animais Geneticamente Modificados , Aromatase/genética , Disruptores Endócrinos/toxicidade , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados/metabolismo , Feminino , Corantes Fluorescentes , Proteínas de Fluorescência Verde/genética , Guias como Assunto , Organização para a Cooperação e Desenvolvimento Econômico , Ovário/efeitos dos fármacos , Ovário/metabolismo , Regiões Promotoras Genéticas , Reprodutibilidade dos Testes , Vitelogeninas/metabolismo , Peixe-Zebra/metabolismo
2.
Chemosphere ; 247: 125865, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31962223

RESUMO

Triflumezopyrim, a new nicotinic acetylcholine receptor (nAChR) inhibition, can effectively control piercing-sucking insect pests such as white-backed planthopper (Sogatella furcifera). At present, there has been no reports on the effects of triflumezopyrim on the population growth and development of S. furcifera. In this experiment, an age-stage two-sex life table was used to evaluate the impact of triflumezopyrim on the biological parameters of S. furcifera. The results showed that the adult preoviposition period (APOP) and total preoviposition period (TPOP) of the F1 generation were significantly higher than those of the F0 and F4 generations, on the contrary the average fecundity, intrinsic rate of increase (r) and finite rate of increase (λ) of the F4 generation were higher than those of the F0 and F1 generations. The results of synergists and enzyme activities indicated that the CarE and P450 activities in the F4 generation were significantly higher than those in the F0 generation (P < 0.05). The protein contents of vitellogenin (Vg) and vitellogenin receptor (VgR) and relative expression quality of VgR in the F4 female adults were also significantly higher than those in the F0 generation (P < 0.05). These results showed that triflumezopyrim at a low concentration could promote the growth and reproduction of S. furcifera, and that may provide a reference for the rational use of triflumezopyrim in the future.


Assuntos
Hemípteros/efeitos dos fármacos , Hemípteros/enzimologia , Controle de Insetos/métodos , Inseticidas/farmacologia , Piridinas/farmacologia , Pirimidinonas/farmacologia , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Relação Dose-Resposta a Droga , Proteínas do Ovo/genética , Proteínas do Ovo/metabolismo , Feminino , Fertilidade/efeitos dos fármacos , Hemípteros/genética , Inseticidas/administração & dosagem , Crescimento Demográfico , Piridinas/administração & dosagem , Pirimidinonas/administração & dosagem , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Reprodução/efeitos dos fármacos , Análise de Sobrevida , Vitelogeninas/genética , Vitelogeninas/metabolismo
3.
Ecotoxicology ; 29(2): 163-174, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31938948

RESUMO

Perfluorooctanoic acid's (PFOA) widespread use, presence and persistence in the aquatic environment has led to an increasing number of studies focusing on its toxicological effects. In Australia, PFOA has been detected in the aquatic environment, however its effects on Australian native fauna are unknown. In this study, male Australian native fish Murray River rainbowfish (Melanotaenia fluviatilis) were exposed to four different concentrations of PFOA (0.01, 0.1, 1 and 10 mg L-1). Variations in thyroid hormones (Triiodothyronine (T3)/Thyroxine (T4)) and the presence of vitellogenin were determined in plasma. Oxidative stress responses were evaluated in gills and liver. Exposure of male fish to PFOA resulted in altered T3/T4 ratios and the presence of vitellogenin in the plasma. Activities of catalase (CAT) and glutathione- S-transferase (GST) were significantly increased in the gills and significantly reduced in the liver. Lipid peroxidation was observed in both tissues showing that vital organs could not neutralize the peroxides generated by oxidative stress resulting from exposure to PFOA. In natural populations exposed to PFOA, such hormonal disturbances can have negative effects, notably through altered capacity to respond to changes in environmental conditions.


Assuntos
Caprilatos/toxicidade , Fluorcarbonetos/toxicidade , Glândula Tireoide/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Austrália , Catalase/metabolismo , Peixes , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo , Glândula Tireoide/fisiologia , Vitelogeninas/metabolismo
4.
Chemosphere ; 240: 124900, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31563099

RESUMO

Spirotetramat (SPT) is a new tetronic acid derivative insecticide used to control scales and aphids; the potential for endocrine disruptor effects in fish could not be finalized with the available data. In this study, zebrafish were selected to assess the endocrine-disrupting effects. Significant decrease of plasma estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT) were observed in both male and female following the spirotetramat exposure; the vitellogenin (VTG) level in females significantly decreased. The expression of the hypothalamic-pituitary-gonad (HPG) axis genes fshr, lhr and esr1 showed significant increase in the gonads, which expression in males is higher than in females. In addition, the activities of capspase-3 and caspase-9 significantly decreased in both males and females liver, while the capspase-3 and caspase-9 were increased in male testis, the mRNA expression levels of genes expression related to the apoptosis pathway were also significantly altered after the spirotetramat exposure. Additionally, we found the parental zebrafish exposed to spirotetramat induced the development delay of its offspring. Above all, the adverse effects induced by spirotetramat suggesting that spirotetramat is a potential exogenous hazardous agent.


Assuntos
Compostos Aza/toxicidade , Inseticidas/toxicidade , Compostos de Espiro/toxicidade , Animais , Apoptose , Disruptores Endócrinos/toxicidade , Estradiol/metabolismo , Estrogênios/farmacologia , Feminino , Expressão Gênica , Gônadas/efeitos dos fármacos , Fígado/metabolismo , Masculino , Testículo/efeitos dos fármacos , Testosterona/análogos & derivados , Vitelogeninas/metabolismo , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo
5.
Aquat Toxicol ; 217: 105336, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31733503

RESUMO

It is widely recognized that endocrine disrupting chemicals (EDCs) released into the environment through anthropogenic activities can have short-term impacts on physiological and behavioral processes and/or sustained or delayed long-term developmental effects on aquatic organisms. While numerous studies have characterized the effects of EDCs on temperate fishes, less is known on the effects of EDCs on the growth and reproductive physiology of tropical species. To determine the long-term effects of early-life exposure to common estrogenic chemicals, we exposed Mozambique tilapia (Oreochromis mossambicus) yolk-sac fry to 17ß-estradiol (E2) and nonylphenol (NP) and subsequently characterized the expression of genes involved in growth and reproduction in adults. Fry were exposed to waterborne E2 (0.1 and 1 µg/L) and NP (10 and 100 µg/L) for 21 days. After the exposure period, juveniles were reared for an additional 112 days until males were sampled. Gonadosomatic index was elevated in fish exposed to E2 (0.1 µg/L) while hepatosomatic index was decreased by exposure to NP (100 µg/L). Exposure to E2 (0.1 µg/L) induced hepatic growth hormone receptor (ghr) mRNA expression. The high concentration of E2 (1 µg/L), and both concentrations of NP, increased hepatic insulin-like growth-factor 1 (igf1) expression; E2 and NP did not affect hepatic igf2 and pituitary growth hormone (gh) levels. Both E2 (1 µg/L) and NP (10 µg/L) induced hepatic igf binding protein 1b (igfbp1b) levels while only NP (100 µg/L) induced hepatic igfbp2b levels. By contrast, hepatic igfbp6b was reduced in fish exposed to E2 (1 µg/L). There were no effects of E2 or NP on hepatic igfbp4 and igfbp5a expression. Although the expression of three vitellogenin transcripts was not affected, E2 and NP stimulated hepatic estrogen receptor (erα and erß) mRNA expression. We conclude that tilapia exposed to E2 and NP as yolk-sac fry exhibit subsequent changes in the endocrine systems that control growth and reproduction during later life stages.


Assuntos
Estradiol/toxicidade , Hormônio do Crescimento/metabolismo , Fenóis/toxicidade , Receptores Estrogênicos/metabolismo , Somatomedinas/metabolismo , Tilápia/crescimento & desenvolvimento , Poluentes Químicos da Água/toxicidade , Animais , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Fígado/efeitos dos fármacos , Masculino , Reprodução/efeitos dos fármacos , Tilápia/metabolismo , Vitelogeninas/metabolismo
6.
Aquat Toxicol ; 216: 105321, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31586886

RESUMO

Estrogen pollution in marine environments has become a research hotspot due to its adverse effects on the reproduction of wild organisms. To early detection of estrogen pollution, this study developed two methods for detecting Japanese flounder vitellogenin (Vtg), a sensitive biomarker for environmental estrogens. Firstly, monoclonal antibodies (mAb) specific to Vtg were prepared using purified lipovitellin (Lv), a main Vtg-derived yolk protein. Anti-Lv mAb (C1F1) had the highest titer (1:256,000) and was labeled with fluorescein isothiocyanate to establish a direct immunofluorescence (DIF) method for histological detection of Vtg in tissues. Additionally, using the purified Lv and mAb, an enzyme-linked immunosorbent assay (ELISA) was developed and this assay had a detection limit of 0.75 ng/mL and a working range of 1.95-250 ng/mL. Furthermore, Vtg induction in the plasma of Japanese flounder exposed to 17ß-estradiol (E2), 17α-ethinylestradiol (EE2), and bisphenol A (BPA) were quantified by ELISA, and Vtg induction in the liver of EE2-exposed Japanese flounder were measured by DIF. Finally, the distribution of Vtg in Japanese flounder was detected using these two methods. The results revealed that Vtg mainly appeared in the terminal tail fin, liver, kidney, intestine, and spleen. Considering the high concentration of Vtg and easy sample collection, the terminal tail fin could be a new alternative to plasma for Vtg quantification, while kidney and liver are suitable for histological detection of Vtg.


Assuntos
Organismos Aquáticos/metabolismo , Biomarcadores/análise , Estrogênios/toxicidade , Linguado/metabolismo , Vitelogeninas/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Anticorpos Monoclonais/metabolismo , Especificidade de Anticorpos , Compostos Benzidrílicos/toxicidade , Exposição Ambiental , Estradiol/análise , Etinilestradiol/toxicidade , Linguado/sangue , Fenóis/toxicidade , Vitelogeninas/sangue
7.
Parasit Vectors ; 12(1): 500, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31653232

RESUMO

BACKGROUND: The hard tick Haemaphysalis longicornis (Ixodidae) is widely distributed in East Asia, China, Australia and New Zealand. It can transmit many infectious pathogens, including the causative agents of human rickettsiosis, bovine theileriosis, bovine babesiosis and canine babesiosis. Therefore, a greater understanding of H. longicornis biology might aid in the development of more effective control measures against the tick and tick-borne pathogens. METHODS: We analyzed the expression of miR-184 in different developmental stages and various tissues of H. longicornis using real-time PCR (qRT-PCR). Antagomir (Ant-184) was used to knock-down miR-184, whilst Ms-Ant and non-injected ticks were used as the negative and blank controls, respectively. We used online software tools (RNAhybrid and TargetScan) to predict the putative target genes of miR-184. RESULTS: The expression of miR-184 was highest in unfed nymphs and lowest in unfed larvae. The tissue distribution of miR-184 showed abundant expression in the midgut. To investigate the probable roles of miR-184, antagomir (Ant-184) was used to knock-down miR-184 (t(4) = 12.32, P = 0.0002). After inhibiting miR-184, other biological factors were examined in each group. The engorged body weight was significantly reduced in the treated group (Ant-184) in contrast to control groups (t(22) = 2.19, P = 0.0388). The mean duration of the egg-laying days was significantly increased (33.5 ± 1.91) and the number of eggs (t(10) = 3.147, P = 0.0137), and egg mass (t(10) = 3.4472, P = 0.0063) were significantly reduced in the treated group. During oviposition, eggs were monitored and in half of the ticks of the Ant-184 group the eggs were completely desiccated, lacked embryo development and did not hatch. We analyzed the expression of Vg proteins (Vg1, Vg2, Vg3) in semi-engorged ticks, engorged ticks, ticks at day 2 after engorgement and egg stage in Ant-184, non-injected and Ms-Ant groups, and found significant variation. CONCLUSIONS: This study provides information on the role of miR-184 in H. longicornis ticks. The data suggest that miR-184 targets Vg proteins and affects blood digestion and oviposition.


Assuntos
Ixodidae/fisiologia , MicroRNAs/metabolismo , Animais , Antagomirs/farmacologia , DNA Complementar/análise , Digestão/genética , Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Inativação Gênica/fisiologia , MicroRNAs/genética , Oviposição/genética , RNA/genética , RNA/isolamento & purificação , Coelhos , Reação em Cadeia da Polimerase em Tempo Real , Controle de Ácaros e Carrapatos/métodos , Vitelogeninas/genética , Vitelogeninas/metabolismo
8.
Ecotoxicol Environ Saf ; 185: 109683, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31550567

RESUMO

Thiamethoxam has emerged as an environmental contaminant detected in aqueous environments, and its endocrine-disrupting effect at chronic exposure in teleosts remains unknown. In the present study, a docking experiment and an in vivo test were integrated to systematically explore the toxic mechanisms of thiamethoxam in fish. Histological analysis, plasma VTG and hormone level (E2, 11-KT, T3 and T4) determinations, and HPG and HPT gene expression quantification were performed after Chinese rare minnow (Gobiocypris rarus) was exposed to thiamethoxam (0, 0.5, 5, and 50 µg/L) for 90 days. According to the docking study, thiamethoxam had different interactions with ERα, AR and TRα via hydrogen bonding. A decrease in body length and plasma T4 was observed in both genders. The histological damage in liver and delayed gonadal development were observed in both genders at 50 µg/L thiamethoxam treatment. In males, the following HPG axis genes were upregulated: gnrh and cyp19b in the brain; vtg and cyp19a in the liver; and cyp17 and cyp19a in the gonad. In females, erɑ in the liver was significantly upregulated with 0.5 µg/L thiamethoxam treatment, and cyp17 in the gonad was upregulated with all treatment. The suppression of cyp19a, gnrh, cyp11a, and ttr was observed at the concentration of 5 µg/L in the female liver. Taken together, the endocrine system of Chinese rare minnow might be disrupted after chronic exposure to thiamethoxam.


Assuntos
Cyprinidae/metabolismo , Disruptores Endócrinos/toxicidade , Sistema Endócrino/efeitos dos fármacos , Hormônios/metabolismo , Tiametoxam/toxicidade , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Cyprinidae/genética , Sistema Endócrino/metabolismo , Feminino , Gônadas/efeitos dos fármacos , Gônadas/metabolismo , Humanos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Simulação de Acoplamento Molecular , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo , Glândula Tireoide/patologia , Regulação para Cima , Vitelogeninas/metabolismo
9.
Mol Cell Biol ; 39(23)2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31548262

RESUMO

The enhancer/promoter of the vitellogenin II gene (VTG) has been extensively studied as a model system of vertebrate transcriptional control. While deletion mutagenesis and in vivo footprinting identified the transcription factor (TF) binding sites governing its tissue specificity, DNase hypersensitivity and DNA methylation studies revealed the epigenetic changes accompanying its hormone-dependent activation. Moreover, upon induction with estrogen (E2), the region flanking the estrogen-responsive element (ERE) was reported to undergo active DNA demethylation. We now show that although the VTG ERE is methylated in embryonic chicken liver and in LMH/2A hepatocytes, its induction by E2 was not accompanied by extensive demethylation. In contrast, E2 failed to activate a VTG enhancer/promoter-controlled luciferase reporter gene methylated by SssI. Surprisingly, this inducibility difference could be traced not to the ERE but rather to a single CpG in an E-box (CACGTG) sequence upstream of the VTG TATA box, which is unmethylated in vivo but methylated by SssI. We demonstrate that this E-box binds the upstream stimulating factor USF1/2. Selective methylation of the CpG within this binding site with an E-box-specific DNA methyltransferase, Eco72IM, was sufficient to attenuate USF1/2 binding in vitro and abolish the hormone-induced transcription of the VTG gene in the reporter system.


Assuntos
Expressão Ectópica do Gene/genética , Receptor alfa de Estrogênio/genética , Vitelogeninas/genética , Animais , Sítios de Ligação , Linhagem Celular , Embrião de Galinha , Ilhas de CpG/genética , Metilação de DNA/genética , Proteínas de Ligação a DNA/metabolismo , DNA-Citosina Metilases/metabolismo , Expressão Ectópica do Gene/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Estrogênios/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Genes Reporter , Humanos , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Sequências Reguladoras de Ácido Nucleico , Fatores de Transcrição/metabolismo , Vitelogeninas/metabolismo
10.
Bull Environ Contam Toxicol ; 103(5): 689-696, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31506728

RESUMO

To test the toxic effects of tributyltin (TBT), Macrobrachium rosenbergii were exposed to three concentrations of TBT viz. 10 ng/L, 100 ng/L and 1000 ng/L for 90 days. The bioaccumulation of TBT level varied in hepatopancreas based upon dose dependent manner. Histopathological results revealed the reduction in basement membrane thickness, disruption of the hepatopancreatic tubules and abnormal lumen in hepatopancreas of TBT treated prawns. The ultrastructure of the control prawn showed normal architecture of cellular organelles with prominent nuclei in hepatocytes. On the other hand, many vacuoles, irregular arrangements of microvilli, swollen mitochondria, distorted rough endoplasmic reticulum cisternaes and abnormal nucleus were seen in the TBT treated group. Further, the biochemical and vitellogenin content were altered remarkably due to TBT exposure. It directly indicated that TBT had conspicuously inhibited the vitellogenesis. Therefore, it was inferred that the administration of TBT has considerably affected the hepatopancreatic functions in M. rosenbergii.


Assuntos
32418 , Água Doce/química , Hepatopâncreas/efeitos dos fármacos , Palaemonidae/efeitos dos fármacos , Compostos de Trialquitina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Hepatopâncreas/metabolismo , Palaemonidae/metabolismo , Palaemonidae/ultraestrutura , Compostos de Trialquitina/metabolismo , Vitelogeninas/metabolismo , Poluentes Químicos da Água/metabolismo
11.
Aquat Toxicol ; 216: 105285, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31546070

RESUMO

2-bromo-4, 6-dinitroaniline (BDNA) is a mutagenic aromatic amine involved in the production and degradation of Disperse blue 79, one of the most extensively used brominated azo dyes. In our previous study, a multigenerational exposure of BDNA (0.5, 5, 50 and 500 µg/L) to zebrafish from F0 adult to F2 larvae including a recovery group in F2 larvae was conducted. The effects on apical points observed in individuals and the long-term effects predicted on population were all related to reproduction. In this study, we performed molecular analysis to elucidate the underlying mechanisms of the reproductive toxicity of BDNA. In F1 generation, measurement of vitellogenin and transcription levels of genes associated with hypothalamus-pituitary-gland (HPG) axis, estrogen receptor (ER) and androgen receptor (AR) were conducted. There was a decrease in VTG level in the blood of F1 female fish and transcription of genes related to ER was more affected than that of genes related to AR. These results were consistent with adverse effects that sexual differentiation was biased towards males and fecundity was impaired in a concentration-dependent manner in adults of F1 generation after 150 days exposure. In F2 generation, global gene transcriptions of F2 larvae were investigated. It was uncovered that processes related to apoptosis, development and DNA damage were strongly affected. Alterations to these biological pathways accounted for the irreversible parental influence on a significant decrease in hatchability and increase in abnormality of F2 larvae. All evidence suggested that the multigenerational exposure of BDNA posed lasting effects transmitted from parents to offspring that persisted after exposure ceased.


Assuntos
Compostos de Anilina/toxicidade , Exposição Ambiental , Reprodução/efeitos dos fármacos , Testes de Toxicidade , Peixe-Zebra/metabolismo , Animais , Dano ao DNA , Feminino , Larva/efeitos dos fármacos , Larva/metabolismo , Masculino , Análise de Componente Principal , Transcrição Genética/efeitos dos fármacos , Transcriptoma/genética , Vitelogeninas/metabolismo , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/genética
12.
Aquat Toxicol ; 215: 105261, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31419757

RESUMO

Harmful cyanobacteria and their production of microcystins (MCs) exert significant toxicity on reproduction of fish, especially the process of oogenesis. Our previous studies demonstrated that MCs have negative impacts on the quantity and quality of mature oocytes in female zebrafish. However, the underlying mechanisms of MCs disrupting oocyte maturation (OM) have been rarely reported. In the present study, in vitro oocytes (immature) were separated from zebrafish and treated with 1, 10, 100 µg/L MC-LR. The serine/threonine protein phosphatase 2A (PP2A) activity was downregulated significantly in oocytes exposed to 10 and 100 µg/L MC-LR for both 2 and 4 h. The phosphorylation levels of mitogen-activated protein kinase (MAPK) were detected without noticeable change in all oocytes treated with MC-LR for 2 h, whereas the activated levels of MAPK subtypes (ERK, p38 and JNK) increased remarkably in the 100 µg/L MC-LR treatment of 4 h. In the oocytes exposed to 100 µg/L MC-LR for 4 h, germinal vesicle breakdown (GVBD) rates changed abnormally and maturation-promoting factor (MPF) activity increased significantly, in accordance with the upregulation of Cyclin B protein levels. Moreover, the MAPK inhibitors (10 µM) were applied to explore the role of MAPK subtypes during MC-LR influencing OM and results showed that ERK inhibitor U0126 and p38 inhibitor SB203580 mitigated the effects of 100 µg/L MC-LR-induced MAPK hyper-phosphorylation and elevated GVBD in the oocytes. In conclusion, the present study indicates that microcystins disrupt the meiotic maturation by the pathway of MC-PP2A-MAPK-OM due to the phosphorylation disorder in oocytes.


Assuntos
Técnicas de Maturação in Vitro de Oócitos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Microcistinas/toxicidade , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Peixe-Zebra/fisiologia , Animais , Ciclina B/metabolismo , Ativação Enzimática/efeitos dos fármacos , Feminino , Fator Promotor de Maturação/metabolismo , Oócitos/efeitos dos fármacos , Oócitos/enzimologia , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteína Fosfatase 2/metabolismo , Vitelogeninas/metabolismo , Poluentes Químicos da Água/toxicidade
13.
Arch Environ Contam Toxicol ; 77(3): 390-408, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31422435

RESUMO

One of the direct causes of biodiversity loss is environmental pollution resulting from the use of chemicals. Different kinds of chemicals, such as persistent organic pollutants and some heavy metals, can be endocrine disruptors, which act at low doses over a long period of time and have a negative effect on the reproductive and thyroid system in vertebrates worldwide. Research on the effects of endocrine disruptors and the use of bioindicators in neotropical ecosystems where pressure on biodiversity is high is scarce. In Chile, although endocrine disruptors have been detected at different concentrations in the environments of some ecosystems, few studies have been performed on their biological effects in the field. In this work, Xenopus laevis (African clawed frog), an introduced species, is used as a bioindicator for the presence of endocrine disruptors in aquatic systems with different degrees of contamination in a Mediterranean zone in central Chile. For the first time for Chile, alterations are described that can be linked to exposure to endocrine disruptors, such as vitellogenin induction, decreased testosterone in male frogs, and histological changes in gonads. Dioxin-like and oestrogenic activity was detected in sediments at locations where it seem to be related to alterations found in the frogs. In addition, an analysis of land use/cover use revealed that urban soil was the best model to explain the variations in frog health indicators. This study points to the usefulness of an invasive species as a bioindicator for the presence of endocrine-disruptive chemicals.


Assuntos
Disruptores Endócrinos/toxicidade , Biomarcadores Ambientais , Exposição Ambiental/análise , Poluição Ambiental/efeitos adversos , Xenopus laevis/fisiologia , Animais , Linhagem Celular Tumoral , Chile , Ecossistema , Ecotoxicologia/métodos , Disruptores Endócrinos/análise , Poluentes Ambientais/toxicidade , Feminino , Sedimentos Geológicos/análise , Gônadas/patologia , Humanos , Espécies Introduzidas , Masculino , Reprodução , Testosterona/metabolismo , Vitelogeninas/metabolismo
14.
Aquat Toxicol ; 214: 105241, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31301543

RESUMO

The purpose of this study was to investigate the bioaccumulation and biochemical responses exposed to one of the main organic ultraviolet (UV) pollutants in the environment, ethylhexyl methoxy cinnamate (EHMC), and its main transformation product, either alone or in combination in zebrafish (Danio rerio). Four-month-old zebrafish were exposed to EHMC (34.4, 344 nmol/L) solution for 14 days, the species and contents of EHMC transformation products in zebrafish were determined and 3,5-dichloro-2-hydroxyacetophenone (3,5DCl2HAcP) was the one with the highest concentration in transformation products. Then, zebrafish were exposed to EHMC, 3,5DCl2HAcP alone and mixed solution for 21 days. At 7, 14 and 21 d, the related indexes of antioxidant defense system were determined. Results showed that both EHMC and 3,5DCl2HAcP can lead to the increase of malondialdehyde (MDA) and glutathione (GSH) contents, superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) activities in visceral mass compared with the corresponding control group, thus produced oxidative stress effect in organism and 3,5DCl2HAcP even showed stronger oxidative stress than EHMC. The effects of the two lower concentration co-exposure groups were similar and more significant to that of single exposure groups, while excessive oxidative stress occurred at the highest co-exposure group indicated by the decrease of GSH content, SOD, CAT, GR activities and the continued increase of MDA content. At 21 d, estradiol (E2), vitellogenin (Vtg) and testosterone (T) contents, estrogen receptor (Esr), progesterone receptor (Pgr), androgen receptor (Ar), Vtg1, P450 aromatase (Cyp19a1) and 17ß-hydroxysteroid dehydrogenase (Hsd17b3) expression were all significantly increased when exposed to 3,5DCl2HAcP alone, showing complex estrogen and androgen effects. When exposed to EHMC alone, E2 and Vtg contents, Esr, Pgr, Vtg1, Cyp19a1 and Hsd17b1 gene expression levels decreased significantly, and T content and Ar and Hsd17b3 expression increased significantly, indicated that EHMC can produce anti-estrogen and androgen effect. Last, the decrease of estrogen effect and increase of androgen effect in co-exposure group suggested that 3,5DCl2HAcP might weaken the estrogen effect and promote the androgen effect of EHMC.


Assuntos
Cinamatos/metabolismo , Peixe-Zebra/metabolismo , Acetofenonas/metabolismo , Animais , Antioxidantes/metabolismo , Biotransformação/efeitos dos fármacos , Catalase/metabolismo , Cinamatos/toxicidade , Estradiol/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Malondialdeído/metabolismo , Músculos/efeitos dos fármacos , Músculos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Testosterona/metabolismo , Vitelogeninas/metabolismo , Poluentes Químicos da Água/toxicidade
15.
BMC Dev Biol ; 19(1): 14, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-31277577

RESUMO

BACKGROUND: Insulin/insulin-like growth peptide signaling (IIS) down-regulates hemolymph sugar level and facilitates larval growth in the soybean pod borer, Maruca vitrata. The objective of this study is to determine whether IIS of M. vitrata can mediate ovarian development of adult females. RESULTS: A pair of ovaries consists of 8 ovarioles, each of which is separated into distal germarium and proximal vitellarium in M. vitrata. In the germarium, oocyte development occurred with active mitotic activity which was visible by incorporating bromodeoxyribose uridine. Previtellogenic development and subsequent vitellogenesis began soon after adult emergence. They continued with increase of female age. Oocyte development was facilitated by up-regulation of vitellogenin (Vg) and Vg receptor (VgR) gene expression. Larval diets significantly influenced on ovarian development of M. vitrata because oocyte development varied with pupal size derived from larvae treated with different nutritional diets. Its ovarian development was dependent on endocrine signal(s) from the head because decapitation soon after adult emergence prevented oogenesis and subsequent vitellogenesis along with marked reduction of Vg and VgR expression. Topical application of juvenile hormone (JH) significantly recovered its ovarian development whereas farnesoic acid (a precursor of JH biosynthesis) or 20-hydroxyecdysone treatment did not. JH stimulated vitellogenesis and choriogenesis, but not previtellogenic development. In contrast, insulin injection to decapitated females stimulated oocyte differentiation and vitellogenesis along with increase of Vg and VgR expression. To further analyze the effect of insulin on ovarian development, expression of four IIS components (InR, FOXO, Akt, and TOR) genes was manipulated by RNA interference. Hemocoelic injection of gene-specific double stranded RNAs significantly reduced their target gene mRNA levels and interfered with ovarian development. An addition of insulin to JH treatment against decapitated females enhanced the gonadotropic effect of JH by stimulating oogenesis. CONCLUSIONS: IIS plays crucial role in mediating previtellogenic development of M. vitrata in response to nutrient signal. It also enhances the gonadotropic effect of JH II on vitellogenesis.


Assuntos
Fator de Crescimento Insulin-Like I/metabolismo , Insulina/metabolismo , Hormônios Juvenis/metabolismo , Ovário/crescimento & desenvolvimento , Vitelogênese/fisiologia , Animais , Ecdisterona/farmacologia , Proteínas do Ovo/genética , Proteínas do Ovo/metabolismo , Ácidos Graxos Insaturados/farmacologia , Feminino , Proteína Forkhead Box O1/genética , Mariposas , Oogênese/fisiologia , Proteínas Proto-Oncogênicas c-akt/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores de Somatomedina/genética , Serina-Treonina Quinases TOR/genética , Vitelogeninas/genética , Vitelogeninas/metabolismo
16.
Regul Toxicol Pharmacol ; 108: 104424, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31330157

RESUMO

The fish short-term reproduction assay (FSTRA) is an in vivo screen to assess potential interactions with the fish endocrine system. After a 21-day exposure period vitellogenin (VTG) and secondary sexual characteristics are measured in males and females. Egg production and fertility are also monitored daily throughout the test. This paper presents data from 49 studies performed to satisfy test orders from the United States Environmental Protection Agency's Endocrine Disruptor Screening Program. Data Evaluation Records were used to collate the typical control variability and performance of test parameters in FSTRAs conducted in different laboratories with fathead minnow (Pimephales promelas). We also examine the statistical power of FSTRA endpoints and assess whether available historical control data (HCD) assist evidence-based interpretation of the endpoints. Statistically significant inter-laboratory differences were found for all endpoints except survival. HCD could therefore be usefully developed on a laboratory-by-laboratory basis to aid interpretation of new study data. Reliable HCD ranges could be developed for survival, body weight/length, gonadal somatic index, fertilisation success, and male tubercle score, and used in association with stated test acceptability criteria to interpret FSTRA data. In contrast, high intra- and inter-laboratory control variability for VTG and fecundity means that HCD for these endpoints are of limited use during study interpretation.


Assuntos
Bioensaio , Grupos Controle , Disruptores Endócrinos/toxicidade , Reprodução/efeitos dos fármacos , Testes de Toxicidade , Animais , Peso Corporal/efeitos dos fármacos , Cyprinidae , Feminino , Fertilidade/efeitos dos fármacos , Gônadas/efeitos dos fármacos , Laboratórios , Masculino , Reprodutibilidade dos Testes , Vitelogeninas/metabolismo
17.
Environ Pollut ; 253: 749-758, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31344537

RESUMO

The effect of selenium (Se) on the reproductive system has been investigated in both humans and vertebrates, but few studies of female fertility and reproduction in invertebrate have been reported. This study is aimed to investigate the effect of SeMet on growth performance and reproductive system after crayfish were fed with graded levels of dietary SeMet (0, 1.49, 3.29, 10.02, 30.27 or 59.8 µg Se/g dry weight) for 60 days. Crayfish treated with the high levels of SeMet (10.02, 30.27 and 59.76 µg Se/g) exhibited decreasing FW and CL in both male and female. Interestingly, Se accumulation was higher in ovary than in other tissues, suggesting that ovary may serve as a target organ for Se accumulation. We found that dietary Se concentration of 10.02 µg Se/g significantly improved the spawning rate, promoted the synchronized spawning, and up-regulated the expressions of mRNA of cdc2 and vitellogenin, with significantly increased E2 and VTG concentrations in hemolymph of female crayfish. However, a marked decrease of the E2 contents and spawning rate was observed in the groups treated with 30.27 and 59.76 µg Se/g diets. In conclusion, the results of this study indicated that the Se had maximum accumulation in ovary, affecting the reproductive capacity by intervening the expression of cdc2 and vitellogenin in the reproductive system. The LOAEL to induce FW was observed in crayfish fed with 10.02 µg Se/g diet, and its value can cause toxicity within the range of natural concentration, so the addition of Se in the feed should be within 10.02 µg Se/g.


Assuntos
Astacoidea/fisiologia , Exposição Dietética/análise , Selenometionina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Astacoidea/metabolismo , Dieta , Feminino , Hemolinfa/metabolismo , Humanos , Isótopos , Masculino , Ovário , Reprodução , Alimentos Marinhos , Selênio , Vitelogeninas/metabolismo
18.
Dev Comp Immunol ; 99: 103399, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31195052

RESUMO

Recent studies have provided molecular evidence that gut symbiotic bacteria modulate host insect development, fitness and reproduction. However, the molecular mechanisms through which gut symbionts regulate these aspects of host physiology remain elusive. To address these questions, we prepared two different Riptortus-Burkholderia insect models, Burkholderia gut symbiont-colonized (Sym) Riptortus pedestris insects and gut symbiont-noncolonized (Apo) insects. Upon LC-MS analyses, juvenile hormone III skipped bisepoxide (JHSB3) was newly identified from Riptortus Apo- and Sym-female and male adults' insect hemolymph and JHSB3 titer in the Apo- and Sym-female insects were measured because JH is important for regulating reproduction in adult insects. The JHSB3 titer in the Sym-females were consistently higher compared to those of Apo-females. Since previous studies reported that Riptortus hexamerin-α and vitellogenin proteins were upregulated by the topical abdominal application of a JH-analog, chemically synthesized JHSB3 was administered to Apo-females. As expected, the hexamerin-α and vitellogenin proteins were dramatically increased in the hemolymph of JHSB3-treated Apo-females, resulting in increased egg production compared to that in Sym-females. Taken together, these results demonstrate that colonization of Burkholderia gut symbiont in the host insect stimulates biosynthesis of the heteroptera-specific JHSB3, leading to larger number of eggs produced and enhanced fitness in Riptortus host insects.


Assuntos
Burkholderia/fisiologia , Heterópteros/microbiologia , Hormônios Juvenis/metabolismo , Simbiose , Animais , Feminino , Fertilidade/efeitos dos fármacos , Trato Gastrointestinal/microbiologia , Hemolinfa/metabolismo , Heterópteros/fisiologia , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Hormônios Juvenis/administração & dosagem , Masculino , Vitelogeninas/genética , Vitelogeninas/metabolismo
19.
Artigo em Inglês | MEDLINE | ID: mdl-31170475

RESUMO

Vitellogenin (Vtg) is a precursor protein of egg yolk proteins in oviparous and ovoviviparous vertebrates. Except in a case of exposure to estrogenic endocrine disruptors, Vtg is a female-specific protein and could be used as a molecular marker for sex identification. This would be especially useful in the case of the endangered European cave salamander Proteus anguinus in which sexes are indistinguishable according to external morphology, which hinders the establishment of a successful captive breeding program. Here we describe the identification, partial characterization, and purification of Vtg from P. anguinus. Vtg was identified in the plasma of a vitellogenic proteus female with visible oocytes. The identification of this protein was accomplished by mass spectrometry analysis. Two-dimensional gel electrophoresis revealed proteus Vtg as a mix of 190 kDa isoforms with isoelectric points in the pH range 5.3-6.0. Vtg was purified from proteus blood by gel filtration followed by anion-exchange chromatography. Using specific staining of SDS-PAGE gels, the Vtg was found to be phosphorylated and lipidated. Unlike the case in some other aquatic vertebrates, in P. anguinus, Vtg was not present in detectable amounts in cutaneous mucus. Degradation of oocytes in the captive vitellogenic female was accompanied by simultaneous decrease of Vtg concentration. Over a period of 10 months, the concentration of Vtg dropped from maximal to sub-detectable. Our results show that Vtg is a promising molecular marker for sex identification and ovary maturation in P. anguinus, which could contribute to the development of a viable program for captive reproduction of this unique species.


Assuntos
Proteidae/metabolismo , Análise para Determinação do Sexo/métodos , Vitelogeninas/metabolismo , Sequência de Aminoácidos , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Cruzamento , Feminino , Oócitos/citologia , Oócitos/metabolismo , Proteidae/anatomia & histologia , Proteidae/genética , Eslovênia , Vitelogeninas/genética , Vitelogeninas/isolamento & purificação
20.
Environ Pollut ; 252(Pt B): 1059-1067, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31252103

RESUMO

Climate change and pharmaceuticals contamination constitute two of the most relevant stressors on the aquatic ecosystems, however, there is a huge lack of information regarding the interactive effects of both stressors. For that, a mesocosm experiment was implemented where adult zebrafish were exposed to combined temperature and the progestin levonorgestrel (LNG) for 21 days. Considering that the liver is one of the organs where there is a greater metabolization and accumulation of toxicants, the main objective of this work was to assess the effects of both stressors on the female zebrafish hepatocytes morphology and functioning, through stereological and immunohistochemical techniques. Our results revealed an increase of coefficient of variation of the number distribution of hepatocytes volume (CVN(υ)) for individuals exposed to LNG, which denotes an increase of the hepatocytes size variability and is suggestive of functional impacts. This was corroborated by the signs of increased glycogen content with the exposure to increased LNG concentrations and temperature, indicating modified hepatocyte glycogen metabolism. Such disturbances can be considered indicators that the fish had to deal with impacts caused by the stress factors. Regarding the immunoreactivity, from the four proteins selected (catalase, CYP1A, HSP90 and Vtg), just in two of them (catalase and Vtg) were observed some responses to both stressors. For catalase there was a hormetic response, in which exposure to lower LNG concentrations caused a significant higher positive immunostaining than under higher LNG concentrations. While, for Vtg, significant effects of temperature and LNG existed, in which a decline in Vtg immunostaining was observed with exposure to higher temperature and lower LNG concentrations. These results should be seen as a warning sign about fine impacts of multiple stressors, such as temperature and progestogens, on the structure and functioning of zebrafish liver and potentially in other aquatic organisms, and on their health implications.


Assuntos
Levanogestrel/toxicidade , Fígado/efeitos dos fármacos , Fígado/metabolismo , Temperatura , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Catalase/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Feminino , Proteínas de Choque Térmico HSP90/metabolismo , Imuno-Histoquímica , Vitelogeninas/metabolismo
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