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1.
J Hazard Mater ; 478: 135442, 2024 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-39128150

RESUMEN

The brominated azo dye (BAD) Disperse Blue (DB79) is a widespread environmental pollutant. The long-term toxicological effects of DB79 and the mechanisms thereof must be understood to allow assessment of the risks of DB79 pollution. A dual-omics approach employing in silico analysis, bioinformatics, and in vitro bioassays was used to investigate the transgenerational (F0-F2) toxicity of DB79 in zebrafish at environmentally relevant concentrations and identify molecular initiating events and key events associated with DB79-induced fertility disorders. Exposure to 500 µg/L DB79 decreased fecundity in the F0 and F1 generations by > 30 % and increased the condition factor of the F1 generation 1.24-fold. PPARα/RXR and PXR ligand binding activation were found to be critical molecular initiating events associated with the decrease in fecundity. Several key events (changes in fatty acid oxidation and uptake, lipoprotein metabolism, and xenobiotic metabolism and transport) involved in lipid dysregulation and xenobiotic disposition were found to be induced by DB79 through bioinformatic annotation using dual-omics data. The biomolecular underpinnings of decreased transgenerational fertility in zebrafish attributable to BAD exposure were elucidated and novel biomolecular targets in the adverse outcome pathway framework were identified. These results will inform future studies and facilitate the development of mitigation strategies.


Asunto(s)
Fertilidad , Contaminantes Químicos del Agua , Pez Cebra , Animales , Fertilidad/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Compuestos Azo/toxicidad , Femenino , Masculino , Receptor X de Pregnano/genética , Receptor X de Pregnano/metabolismo
2.
PeerJ ; 11: e16472, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38025671

RESUMEN

Amultigenerational study on Ceriodaphnia dubia was carried out by exposing three subsequent generations to pharmaceuticals chlorpromazine (CPZ) and diclofenac (DCF), and two lanthanide chlorides, gadolinium as GdCl3 and europium as EuCl3. As the treatments, environmentally relevant concentrations were chosen (0.001, 0.01 and 0.1 mg/L for CPZ; 0.1, 1 and 10 mg/L for DCF; 0.425, 4.25 and 42.5 µg/L for Gd and 0.41, 4.1 and 41 µg/L for Eu). Survival, population growth and reproduction success were evaluated at 21 and 30 days of exposure, and the whole observation period lasted 40 days. The least sensitive to all selected substances was the first daphnid generation (F1). Within 21-day exposure, no significant effects of the psychotropic drug CPZ on C. dubia survival were observed in generations F1-F3. The anti-inflammatory drug DCF did not affect survival in the F1 generation; however, it significantly reduced survival in the F3 generation at 1-10 mg/L. Both lanthanides did not affect survival in the F1 and F2 generations of C. dubia but considerably decreased survival in the F3 at 4-42 µg/L. Both pharmaceuticals stimulated the reproduction of C. dubia in the F1 generation, while inhibition occurred at the highest tested concentrations in generations F2 and F3. The inhibitory effect on the reproductive success of lanthanides in the F2 generation resembled that for CPZ but not for DCF. The dynamics of adverse effects during the 21-30-day period revealed that despite increased mortality in the controls (up to 30%), concentrations used in the study minified, in most instances, the survival and aggravated population growth and reproduction success of C. dubia. Our data suggest that C. dubia as a test organism can be used for 21 days in multigenerational investigations, especially when testing close to environmental concentrations. In this respect, the standard C. dubia chronic toxicity assay seems limited since prolonged observations and several generations of daphnids are required to obtain reliable information for the risk assessment of potentially aggressive chemicals.


Asunto(s)
Cladóceros , Elementos de la Serie de los Lantanoides , Animales , Clorpromazina/toxicidad , Diclofenaco/toxicidad , Elementos de la Serie de los Lantanoides/toxicidad
3.
Ecotoxicol Environ Saf ; 258: 114990, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37156038

RESUMEN

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic congener of dioxins, has a proven reproductive toxicity. Due to the lack of evidence on the multigenerational female reproductive toxicity of TCDD through the maternal exposure, the current study aims to evaluate, on the one hand, the acute reproductive toxicity of TCDD on adult female pre-gestational exposed to a critical single dose of TCDD (25 µg/kg) for a week (group referred to as AFnG; adult female/non-gestation). On the other hand, the transcription, hormonal and histological effects of TCDD on the females of two generations F1 and F2, were also investigated after the exposure of pregnant females to TCDD on gestational day 13 (GD13) (group referred to as AFG; adult female/gestation). First, our data showed alternations in the ovarian expressional pattern of certain key genes involved in the detoxification of TCDD as well as in the biosynthesis of steroidal hormones. The expression of Cyp1a1 was highly induced in TCDD-AFnG group, but reduced in both F1 and F2. While the transcripts levels of Cyp11a1 and 3ßhsd2 were decreased, Cyp19a1 transcripts were increased as a function of TCDD exposure. This was synchronized with a dramatic increase in the level of estradiol hormone in the females of both experimental groups. Beside a significant reduce in their size and weight, ovaries of TCDD-exposed females showed serious histological alterations marked by atrophy of the ovary, congestion in the blood vessels, necrosis in the layer of granular cells, dissolution of the oocyte and nucleus of ovarian follicles. Finally, the female fertility was dramatically affected across generations with a reduced male\female ratio. Our data indicate that the exposure of pregnant female to TCDD has serious negative effects in the female productive system across generations and suggest the use of hormonal alternation as biomarker to monitor and assess the indirect exposure of these generations to TCDD.


Asunto(s)
Infertilidad Femenina , Dibenzodioxinas Policloradas , Embarazo , Animales , Ratones , Humanos , Femenino , Masculino , Dibenzodioxinas Policloradas/toxicidad , Dibenzodioxinas Policloradas/metabolismo , Ovario , Ratones Endogámicos BALB C , Reproducción , Hormonas/metabolismo
4.
Aquat Toxicol ; 258: 106511, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37011547

RESUMEN

Diflubenzuron, an insecticide commonly used in marine fish farming, has been detected in various marine environments. However, its potential impact on marine fish remains largely unknown. This study investigated the reproductive toxicity of chronic diflubenzuron exposure in female marine medaka (Oryzias melastigma). Marine medaka were exposed continuously to environmentally relevant concentrations of diflubenzuron (0.1, 1, and 10 µg/L) or a solvent control from the fertilized egg to adulthood. In exposed female marine medaka, the gonadosomatic index (GSI) and the number of laid eggs were significantly reduced. Moreover, diflubenzuron-exposed female marine medaka showed altered ovarian histopathology, with an increased relative proportion of immature oocytes and atretic follicles and a decreased relative proportion of mature oocytes. Maternal exposure to diflubenzuron also inhibited the development of the F1 generation, significantly reducing the hatching rate of F1 embryos and significantly increasing the malformation rate of F1 larvae. Furthermore, changes in hormone levels and expression of genes along the hypothalamus-pituitary-gonad-liver (HPGL) axis were observed, which may be the fundamental reason for all the reproductive toxic effects mentioned above. These results provide new insights into the impact of diflubenzuron on the female marine medaka reproductive system and underscore the importance of investigating the potential environmental risks of diflubenzuron in the marine environment.


Asunto(s)
Diflubenzurón , Oryzias , Contaminantes Químicos del Agua , Animales , Femenino , Contaminantes Químicos del Agua/toxicidad , Ovario , Reproducción
5.
Chemosphere ; 316: 137863, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36649895

RESUMEN

Glufosinate-ammonium, the second largest transgene crop resistant herbicide, is classified as a mobile persistent pollutant by the U.S. Environmental Protection Agencybecause of its slow decomposition and easy mobile transfer in a water environment. The chronic and multigeneration toxicity of this compound to environmental organisms are alarming. In this study, racemic glufosinate-ammonium and the effective isomer, l-glufosinate-ammonium, were used as the test agents. The developmental, neurotoxic and reproductive toxicities of Caenorhabditis elegans to their parents and progeny were studied by continuous exposure in water at concentrations of 0.1, 1, 10 and 100 µg/L. The causes of toxicity differences were analysed from oxidative stress and transcription levels. Through oxidative stress of C. elegans, racemic glufosinate-ammonium and l-glufosinate-ammonium both mediated the developmental toxicity (shortened developmental cycle, reduced body length and width, promoted ageingand decreased longevity), neurotoxicity (inhibited head swinging, body bending frequency and acetylcholinesterase [AchE] activity) and reproductive toxicity (significant reductions in the number of eggs and offspring in vivo and induced apoptosis of gonadal cells). These phenomena caused oxidative damage (protein and membrane lipid peroxidation) and further induced apoptosis. The changes in various indicators caused by racemic glufosinate-ammonium exposure were more significant than those caused by l-glufosinate-ammonium exposure, and the reproduction-related indicators were more significant than the developmental and neurological indicators. A continuous accumulation of toxicity was observed after multiple generations of continuous exposure. These research results provide a data reference for the ecotoxicological evaluation and risk assessment of glufosinate-ammonium and contribute to the revision and improvement of the related environmental policies of glufosinate-ammonium.


Asunto(s)
Acetilcolinesterasa , Caenorhabditis elegans , Animales , Caenorhabditis elegans/genética , Aminobutiratos/toxicidad , Reproducción
6.
J Appl Toxicol ; 43(1): 122-145, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-35754092

RESUMEN

A large number of pollutants existing in the environment can last for a long time, and their potential toxic effects can transfer from parents to their offspring. Thus, it is necessary to investigate the toxicity of environmental pollutants across multigenerations and the underlying mechanisms in organisms. Due to its short life cycle and sensitivity to environmental exposures, Caenorhabditis elegans is an important animal model for toxicity assessment of environmental pollutants across multigenerations. In this review, we introduced the transgenerational and multigenerational toxicity caused by various environmental pollutants in C. elegans. Moreover, we discussed the underlying mechanisms for the observed transgenerational and multigenerational toxicity of environmental contaminants in C. elegans.


Asunto(s)
Caenorhabditis elegans , Contaminantes Ambientales , Animales , Caenorhabditis elegans/genética , Contaminantes Ambientales/toxicidad , Exposición a Riesgos Ambientales
7.
Chemosphere ; 313: 137386, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36436584

RESUMEN

Traditional ecotoxicological studies prove to be focused mainly on single-generation, multigenerational research in ecotoxicological testing is needed to improve the predictive approaches in ecological risk assessment. Silver nanoparticles (AgNPs) have been increasingly detected in aquatic environments due to their extensive use in consumer products. We investigated the transgenerational effects of AgNPs on the life traits of freshwater model gastropods Lymnaea stagnalis for two generations. The reversibility of the effects of using recovery experiments was also performed. Results showed that AgNPs induced high Ag bioaccumulation in the whole soft tissues of parental L. stagnalis after 21 days of exposure. The increased ROS production and reduced condition index and fecundity were found after exposure to AgNPs at 500 µg/L. These results highlight that under AgNPs exposure, adult gastropods might allocate more resources to resist oxidative stress rather than to growth or reproduction. Furthermore, the Ag accumulation and ROS production of egg clutches were significantly related to parental exposure duration and concentrations. On the other hand, isolated eggs exposure demonstrated biological effects were persistent in terms of the next generation. For example, after transfer to a clean medium, similar Ag bioaccumulation and ROS production were observed from eggs which parents were pre-exposed to 50 and 500 µg/L AgNPs. Current explicit consideration of offspring performance adds value to existing toxicity testing protocols. Parental exposure duration has important implications for offspring effects, and parental exposure can cause transgenerational changes in resistance that have significant implications for toxicity testing and adaptive responses. These effects across generations point out the need for multigenerational tests to assess the environmental risk of MNPs in aquatic organisms.


Asunto(s)
Nanopartículas del Metal , Contaminantes Químicos del Agua , Animales , Lymnaea/fisiología , Plata/toxicidad , Nanopartículas del Metal/toxicidad , Especies Reactivas de Oxígeno/farmacología , Contaminantes Químicos del Agua/toxicidad , Agua Dulce
8.
Environ Pollut ; 263(Pt A): 114376, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32203849

RESUMEN

With increasing release of nanoparticles (NPs) into the environment, soil organisms likely suffer from high dose and long duration of NPs contamination, while the effect of NPs across multiple generations in soil is rarely studied. Herein, we investigated how multigenerational exposure to different crystal forms (anatase, rutile, and their mixture) of TiO2 NPs (nTiO2) affected the survival, behavior, physiological and biochemical traits, and lifespan of nematodes (C. elegans) in a paddy soil. The soil property changed very slightly after being spiked with nTiO2, and the toxicities of three nTiO2 forms were largely comparable. The nTiO2 exposure adversely influenced the survival and locomotion of nematodes, and increased intracellular reactive oxygen species (ROS) generation. Interestingly, the toxic effect gradually attenuated and the lifespan of survived nematodes increased from the P0 to F3 generation, which was ascribed to the survivor selection and stimulatory effect. The lethal effect and the increased oxidative stress may continuously screen out offspring possessing stronger anti-stress capabilities. Moreover, key genes (daf-2, age-1, and skn-1) in the insulin/IGF-like signaling (IIS) pathway actively responded to the nTiO2 exposure, which further optimized the selective expression of downstream genes, increased the antioxidant enzyme activities and antioxidant contents, and thereby increased the stress resistance and longevity of survived nematodes across successive generations. Our findings highlight the crucial role of bio-responses in the progressively decreased toxicity of nTiO2, and add new knowledge on the long-term impact of soil nTiO2 contamination.


Asunto(s)
Proteínas de Caenorhabditis elegans , Nanopartículas , Animales , Caenorhabditis elegans , Insulina , Longevidad , Estrés Oxidativo , Suelo , Titanio
9.
Sci Total Environ ; 635: 947-955, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29710616

RESUMEN

Despite the fact that the demand for graphene and its derivatives in commercial applications is still growing, many aspects of its toxicity and biocompatibility are still poorly understood. Graphene oxide, which is released into the environment (air, soil and water) as so-called nanowaste or nanopollution, is able to penetrate living organisms. It is highly probable that, due to its specific nature, it can migrate along food chains thereby causing negative consequences. Our previous studies reported that short-term exposure to graphene oxide may increase the antioxidative defense parameters, level of DNA damage, which results in numerous degenerative changes in the gut and gonads. The presented research focuses on reproductive dysfunction and cellular changes in Acheta domesticus after exposure to GO nanoparticles in food (concentrations of 20 and 200 µg·g-1 of food) throughout their entire life cycle. The results showed that long-term exposure to GO caused a significant decrease in the reproductive capabilities of the animals. Moreover, the next generation of A. domesticus had a lower cell vitality compared to their parental generation. It is possible that graphene oxide can cause multigenerational harmful effects.


Asunto(s)
Grafito/toxicidad , Gryllidae/efectos de los fármacos , Nanopartículas/toxicidad , Óxidos/toxicidad , Animales , Exposición Dietética , Fertilidad/efectos de los fármacos , Pruebas de Toxicidad Crónica
10.
Sci Total Environ ; 634: 260-266, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29627549

RESUMEN

The plasticizer di(2-ethylhexyl) phthalate (DEHP) is an emerging organic contaminant that has represented a risk for organisms present in the environment. However, there is still limited information regarding DEHP-induced multigenerational toxicity and the underlying mechanisms. In this study we investigated the multigenerational toxic effects including locomotive behaviors and reproduction upon prolonged DEHP exposure (from larval L1 to adult) and the underlying mechanisms in the nematode Caenorhabditis elegans. The multigenerational effects were examined over 6 generations (F0-F5) with only parental C. elegans (F0) was exposed to DEHP from larval L1 to adults (72h), and the subsequent offsprings (F1-F5) were grown under DEHP-free conditions. The results showed that prolonged exposure (72h) to various concentrations of DEHP caused dose-dependent locomotive impairments and reproduction defects in C. elegans and that a concentration of 0.2mg/L DEHP was enough to cause such sublethal effects. The results showed that after prolonged exposure to DEHP in the F0 generation, abnormal locomotive behaviors such as reduced body bends and head thrashes were observed from generations F0 to F5. Additionally, prolonged exposure to DEHP (20mg/L) in F0 significantly reduced total brood size in F0, and this parental exposure was sufficient to cause multigenerational reproductive toxicity in the offspring generations (F1-F5) as well. Furthermore, the expressions of reproduction-related genes such as vit-2 and vit-6 were down-regulated by about 20% until F3, and the expression of H3Kme2 demethylase, spr-5, was downregulated in F1 by about 40%. Results from this study demonstrate that prolonged exposure to DEHP only at F0 adversely affected reproduction and locomotive behaviors in C. elegans across generations and might be associated with inadequate vitellogenin production and malfunction of H3Kme2 demethylase. This study implies that parentally prolonged exposure to DEHP caused multigenerational defects in both reproduction and locomotive behaviors raising the potential health and ecological risk.


Asunto(s)
Caenorhabditis elegans/fisiología , Dietilhexil Ftalato/toxicidad , Sustancias Peligrosas/toxicidad , Animales , Caenorhabditis elegans/efectos de los fármacos , Reproducción/efectos de los fármacos , Vitelogeninas/metabolismo
11.
Reprod Toxicol ; 78: 169-177, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29689290

RESUMEN

Animal models and human studies showed that in utero cigarette smoke exposure decreases sperm counts of offspring. This study used a mouse model to investigate the effects of maternal exposure to cigarette smoke on reproductive systems in F1 and F2 male offspring. Female ICR mice were exposed either to clean air or to cigarette smoke during pregnancy at the post-implantation stage. Epididymal sperm counts were decreased in a cigarette smoke dose-dependent manner in F1 (by 40-60%) and F2 males (by 23-40%) at postnatal day 56. In F1, the seminiferous epithelium heights were lower in the cigarette smoke-exposed groups than in the control group, and these effects were sustained in F2 males. Results suggest that maternal cigarette smoke exposure during pregnancy can have a multigenerational adverse effect on sperm counts in male offspring, which is mediated through in utero exposure of fetal germ cells to cigarette smoke.


Asunto(s)
Exposición Materna/efectos adversos , Efectos Tardíos de la Exposición Prenatal , Recuento de Espermatozoides , Contaminación por Humo de Tabaco/efectos adversos , Animales , Implantación del Embrión/efectos de los fármacos , Femenino , Masculino , Intercambio Materno-Fetal , Ratones Endogámicos ICR , Tamaño de los Órganos/efectos de los fármacos , Embarazo , Testículo/efectos de los fármacos , Testículo/crecimiento & desarrollo , Testículo/patología , Útero/efectos de los fármacos
12.
Aquat Toxicol ; 194: 94-102, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29172130

RESUMEN

One of the most widely used organic UV filters, 4-methylbenzylidene camphor (4-MBC), is present at high concentrations in offshore waters. The marine copepod Tigriopus japonicus was exposed to different concentrations of 4-MBC (i.e., 0, 0.5, 1, 5 and 10µgL-1) for 4 consecutive generations (F0-F3) to evaluate the impact of 4-MBC on marine ecosystems. The results showed that in the F0 generation, 4-MBC caused significant lethal toxicity in T. japonicas at concentrations of 5 and 10µgL-1 and the nauplii were more sensitive to 4-MBC toxicity than the adults. However in the F1-F3 generations, 4-MBC exposure did not affect the survival rate. The hatching rate and the developmental duration from the nauplii to the copepodite (N-C) and from the nauplii to adult (N-A) decreased significantly in the F1-F2 generations and in the F2-F3 generations, respectively, even at the lowest exposure concentration (0.5µgL-1). In the subsequent two generations (i.e., the F4-F5 generations) of recovery exposure in clean seawater, the growth rates of the original 4-MBC exposure groups were still faster than the control in both the N-C and N-A stages, suggesting possible transgenerational genetic and/or epigenetic changes upon chronic 4-MBC exposure. The expression of the ecdysone receptor gene was up-regulated by 4-MBC, which was consistent with the decrease of the N-C/N-A duration. In addition, 4-MBC may induce oxidative stress and trigger apoptosis in T. japonicas, resulting in developmental, reproductive and even lethal toxicity. A preliminary risk assessment suggested that under environmentally realistic concentrations, 4-MBC had significant potential to pose a threat to marine crustaceans and marine ecosystems.


Asunto(s)
Alcanfor/análogos & derivados , Copépodos/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Animales , Alcanfor/toxicidad , Copépodos/crecimiento & desarrollo , Copépodos/fisiología , Femenino , Longevidad/efectos de los fármacos , Reproducción/efectos de los fármacos
13.
J Hazard Mater ; 339: 281-291, 2017 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-28658637

RESUMEN

Prednisolone (PDS), a potent synthetic glucocorticoid is widely prescribed for its exceptional anti-inflammatory properties. Several studies have detected the environmental presence of PDS in water bodies which has led to an ecological concern for its toxicity to non-target aquatic biota. The present study investigated the effects of exposure to PDS on different life-cycle stages and generations of the freshwater snail, Physa acuta. This continuous exposure over a period of multiple generations resulted in generational impairments at measured endpoints. LOEC values (p<0.001) for PDS exposure ranged from 32 to 4µg/L in exposed F0-F2 generations. Global DNA methylation (% 5-methyl cytosine) of adult progeny was found to be affected at higher test concentrations in comparison to the parent snails. Partially formed to completely missed growth components of shell structure and shell thinning in abnormally underdeveloped PDS exposed snails of F1 and F2 generation, was also observed in this multigenerational exposure experiment. The multigenerational study confirmed P. acuta as a promising bioindicator since critical effects of the long term glucocorticoid exposure opens up the way for further investigations on transgenerational toxicity in environmental toxicology and risk assessment and to monitor glucocorticoid pollution in aqueous ecosystem.


Asunto(s)
Prednisolona/toxicidad , Caracoles/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Exoesqueleto/anomalías , Exoesqueleto/efectos de los fármacos , Animales , Antiinflamatorios/toxicidad , Metilación de ADN/efectos de los fármacos , Caracoles/genética , Caracoles/crecimiento & desarrollo
14.
Ecotoxicol Environ Saf ; 132: 397-402, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27379980

RESUMEN

The effects of both continuous and alternate exposure to 2mgL(-1) of enrofloxacin (EFX) on survival, growth and reproduction were evaluated over four generations of Daphnia magna. Mortality increased, reaching 100% in most groups by the end of the third generation. Growth inhibition was detected in only one group of the fourth generation. Reproduction inhibition was >50% in all groups and, in second and third generations, groups transferred to pure medium showed a greater inhibition of reproduction than those exposed to EFX. To verify whether the effects observed in these groups could be explained by the perinatal exposure to the antibacterial, a reproduction test with daphnids obtained from in vitro exposed D. magna embryos was also carried out. Perinatal exposure to EFX seemed to act as an 'all-or-nothing' toxicity effect as 31.4% of embryos died, but the surviving daphnids did not show any inhibition of reproduction activity. However, the embryonic mortality may at least partially justify the inhibition of reproduction observed in exposed groups along the multigenerational test. Concluding, the multigenerational test with D. magna did show disruption to a population that cannot be evidenced by the official tests. The increasing deterioration across generations might be inferred as the consequence of heritable alterations. Whilst the concentration tested was higher than those usually detected in the natural environment, the increasing toxicity of EFX across generations and the possible additive toxicity of fluoroquinolone mixtures, prevent harm to crustacean populations by effects in the real context from being completely ruled out.


Asunto(s)
Antibacterianos/toxicidad , Daphnia/efectos de los fármacos , Fluoroquinolonas/toxicidad , Animales , Daphnia/embriología , Daphnia/crecimiento & desarrollo , Embrión no Mamífero/efectos de los fármacos , Enrofloxacina , Reproducción/efectos de los fármacos
15.
Environ Pollut ; 208(Pt B): 767-73, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26561446

RESUMEN

In order to understand how bisphenol A (BPA) exposure acts on the evolutionary dynamics of populations and changes of stress response across generations, the model animal Caenorhabditis elegans was used to conduct the multigenerational testing. Multiple endpoints at the physiological (growth, reproduction, and locomotion behaviors) and molecular (stress-related gene expressions) levels were examined by multigenerational exposure to low-concentration BPA (0.001-10 µM) across four generations. The results showed that changes of physiological-level effects across four generations varied in magnitude and direction, depending on the exposure concentrations. C. elegans individuals in the first generation grew smaller, moved slower, and produced less offsprings than the controls by BPA exposure. As for each trait tested, the first generation response could be commonly mirrored in the subsequent generations at the highest concentration of 10 µM. However, at lower concentrations, response of parental generation was a relatively poor predictor of the effects on progeny, as acclimation or cumulative damage could occur in the subsequent generations. The integrated gene expression profiles visually illustrated that the tested gene expressions at low concentrations (0.001-0.01 µM) were more obviously changed in both G1 and G4 generations, and the G1 generation showed a much greater degree of increase in stress-related gene expressions than the G4 generation. The multigenerational toxicity data emphasize the need of considering biological effects over multiple generations to conduct accurate assessment of environmental risks of toxicants on population dynamics.


Asunto(s)
Compuestos de Bencidrilo/toxicidad , Caenorhabditis elegans/efectos de los fármacos , Fenoles/toxicidad , Estrés Fisiológico , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiología , Exposición a Riesgos Ambientales , Regulación de la Expresión Génica/efectos de los fármacos , Modelos Lineales , Locomoción/efectos de los fármacos , Reproducción/efectos de los fármacos , Pruebas de Toxicidad
16.
Aquat Toxicol ; 166: 42-9, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26210816

RESUMEN

Here, through a multigenerational life-cycle test, Tigriopus japonicus were exposed to different mercuric chloride treatments in seawater (nominal concentrations of 0, 0.5, 1, 10, and 50µg/L) for five successive generations (F0-F4), and subsequently all the treatments were recovered in clean environments for one generation (F5). Six life history traits (survival, developmental time for nauplius phase, developmental time to maturation, fecundity, number of clutches, and number of nauplii/clutch) were examined for each generation. Mercury (Hg) accumulation was also analyzed for the adult copepods in the F1, F3, and F5. The results indicated that Hg accumulated in a dose-dependent manner for the F1, F3, and F5 generations. Moreover, higher Hg contents were observed in F3 than F1 at the same exposure levels. Among the six life history traits, only fecundity and number of nauplii/clutch showed a greater sensitivity to Hg toxicity, and the inhibitory effects worsened from F0 to F3, which was explained by a trend for higher metal accumulation with increasing generations. In the recovery generation (F5), none of the traits differed from the control, highlighting that Hg might not induce any epigenetic or parental effects in the following generations. Thus, we hypothesized that although cumulative effects might have been involved in Hg multigenerational toxicity, physiological acclimation, that is, phenotypic plasticity could explain Hg tolerance obtained by marine copepods. Impacts on important life history traits could disturb the population dynamics of some important marine copepods, hence having unexpected ecological consequences in the marine ecosystem. Yet, the Hg harmful impacts rapidly fade away as the Hg is cleared from the environment.


Asunto(s)
Copépodos/efectos de los fármacos , Mercurio/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Fertilidad/efectos de los fármacos , Estadios del Ciclo de Vida/efectos de los fármacos , Agua de Mar/química
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