After the COVID-19 pandemic, the use of quaternary ammonium compounds increased exponentially due to their efficacy as antimicrobials, stabilizers and disinfectants. Among these, Quaternium-15 is a preservative used in the formulation of a variety of personal care products. The increased use of this substance and the resulting persistence in wastewater treatment systems, which are unable to completely remove the Quaternium-15 from the water, is of increasing environmental concern. Using embryotoxicity analyses, this study aimed to investigate the effects of exposure to Quaternium-15 on non-target species and the resulting risks to the environment. Embryotoxicity endpoints such as mortality, hatching, presence of malformations, altered heartbeat and animal length were used to assess the effects on three model organisms (Cyprinus carpio, Danio rerio, Xenopus laevis) were evaluated during a 96-hour exposure to six different concentrations of Quaternium-15 (1, 5, 10, 15, 20 and 25 mg/L). The results obtained from the analyses highlighted: significant mortality for all three model organisms in the highest concentrations tested in which all the embryos died after 96 hpf, a delay in hatching of C. carpio and D. rerio compared to the control group, the insurgence of malformations in all the model organisms chosen and a significant decrease in heartbeat rate for the fish models. Each of these observations underlies the negative interaction between the Quaternium-15 and aquatic organisms making necessary further investigation to prevent damage to ecosystems and non-target species.

• Klíčová slova
• Ammonium compounds, Aquatic vertebrates, Embryotoxicity, Emerging contaminants, Personal care products,
• MeSH
• chemické látky znečišťující vodu * toxicita   MeSH
• dánio pruhované * MeSH
• embryo nesavčí * účinky léků   MeSH
• kapři * MeSH
• konzervační prostředky farmaceutické toxicita   MeSH
• Xenopus laevis MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• konzervační prostředky farmaceutické MeSH

Recent research efforts in endocrine disruption have focused on evaluating non-EATS (estrogen, androgen, thyroid, and steroidogenesis) pathways. Retinoid signaling disruption is noteworthy because of its teratogenic effects and environmental relevance. However, current environmental risk assessments are limited in their ability to evaluate impacts on individuals and populations. This study characterizes an Adverse Outcome Pathway (AOP) network linking retinoid signaling disruption to teratogenicity and survival in zebrafish. We identified Retinoic Acid Receptor (RAR) overactivation as the molecular initiating event leading to key events including craniofacial (CFM) and tail (TM) malformations, posterior swim bladder (SB) non-inflation, impaired swimming performance, and reduced feeding, ultimately resulting in decreased survival. Our study (1) determines critical sensitivity windows for CFM, posterior SB non-inflation, and TM, (2) provides quantitative measurements for CFM and TM, and (3) defines impacts on higher biological levels including food ingestion, swimming, and survival. Results show that all-trans retinoic acid (ATRA) induces strong teratogenic effects with sensitivity windows between 4 and 48 h post fertilization (hpf) for CFM, TM, and posterior SB non-inflation. TM is the most sensitive indicator, with EC50 of 0.2 - 0.26 µg/L across exposure windows 4-48, 4-72, 4-96, and 4-120 hpf. Besides inducing known malformations, ATRA impaired posterior SB inflation with EC50 of 1 - 1.21 µg/L across the same exposure windows. ATRA exposure (1 µg/L) resulted in 50 % food ingestion inhibition at 7 days post fertilization (dpf) and 10 % survival at 14 dpf. This study provides a regulatory-relevant framework linking developmental effects to population outcomes, highlighting ecological risks and needs for improved risk assessments.

• Klíčová slova
• Adverse outcome pathway, Behavior toxicity, Developmental toxicity, Endocrine disruption, Retinoic acid, Retinoids, Survival/mortality, Teratogenicity,
• MeSH
• chemické látky znečišťující vodu * toxicita   MeSH
• dánio pruhované * MeSH
• dráhy škodlivých účinků * MeSH
• embryo nesavčí * účinky léků   MeSH
• receptory kyseliny retinové metabolismus   genetika   MeSH
• retinoidy metabolismus   MeSH
• signální transdukce * účinky léků   MeSH
• teratogeny * toxicita   MeSH
• tretinoin * metabolismus   toxicita   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• receptory kyseliny retinové MeSH
• retinoidy MeSH
• teratogeny * MeSH
• tretinoin * MeSH

BACKGROUND: Previous studies have claimed that pharyngeal teeth in medaka (Oryzias latipes) are induced independent of retinoic acid (RA) signaling, unlike in zebrafish (Danio rerio). In zebrafish, pharyngeal tooth formation depends on a proper physical contact between the embryonic endodermal pouch anterior to the site of tooth formation, and the adjacent ectodermal cleft, an RA-dependent process. Here, we test the hypothesis that a proper pouch-cleft contact is required for pharyngeal tooth formation in embryonic medaka, as it is in zebrafish. We used 4-[diethylamino]benzaldehyde (DEAB) to pharmacologically inhibit RA production, and thus pouch-cleft contacts, in experiments strictly controlled in time, and analyzed these using high-resolution imaging. RESULTS: Pharyngeal teeth in medaka were present only when the corresponding anterior pouch had reached the ectoderm (i.e., a physical pouch-cleft contact established), similar to the situation in zebrafish. Oral teeth were present even when the treatment started approximately 4 days before normal oral tooth appearance. CONCLUSIONS: RA dependency for pharyngeal tooth formation is not different between zebrafish and medaka. We propose that the differential response to DEAB of oral versus pharyngeal teeth in medaka could be ascribed to the distinct germ layer origin of the epithelia involved in tooth formation in these two regions.

• Klíčová slova
• dentition, ectoderm, endoderm, germ layers, pharyngeal pouches, zebrafish,
• MeSH
• dánio pruhované embryologie   MeSH
• embryo nesavčí účinky léků   MeSH
• farynx embryologie   účinky léků   MeSH
• Oryzias * embryologie   MeSH
• tretinoin * metabolismus   farmakologie   MeSH
• zuby * embryologie   účinky léků   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• tretinoin * MeSH

Environmental pollutants capable of interfering with the thyroid hormone (TH) system increasingly raise concern for both human and environmental health. Recently, resorcinol has received attention as a compound of concern due to its endocrine disrupting properties. It is a known inhibitor of thyroperoxidase (TPO), an enzyme required in TH synthesis, and therapeutic use of resorcinol exposure has led to hypothyroidism in humans. There is limited evidence concerning ecotoxicologically relevant effects of resorcinol in fish. A set of adverse outcome pathways (AOPs) has recently been developed linking thyroid hormone system disruption (THSD) to impaired swim bladder inflation and eye development in fish. In the present study, these AOPs were used to provide the background for testing potential THSD effects of resorcinol in zebrafish eleutheroembryos. We exposed zebrafish eleutheroembryos to resorcinol and assessed TH levels, swim bladder inflation and eye morphology. As a TPO inhibitor, resorcinol is expected to affect TH levels and eye morphology but not swim bladder inflation during embryonic development. Indeed, thyroxine (T4) levels were significantly decreased following resorcinol exposure. In contrast to our hypothesis, swim bladder inflation was impaired at 5 days post fertilization (dpf) and no effects on eye morphology were detected. Therefore, in vitro assays were performed to identify potential additional thyroid hormone system disruption-related mechanisms through which resorcinol may act. Two new mechanisms were identified: TH receptor (TR) antagonism and transthyretin (TTR) binding inhibition. Both of these mechanisms can plausibly be linked to impaired swim bladder inflation and could, therefore, explain the observed effect. Overall, our study contributes to the knowledge of the THSD potential of resorcinol both in vivo in the zebrafish model as well as in vitro.

• Klíčová slova
• Thyroid hormone system disruption, adverse outcome pathway, eye development, swim bladder inflation, thyroid hormone levels, zebrafish embryo,
• MeSH
• chemické látky znečišťující vodu toxicita   MeSH
• dánio pruhované * MeSH
• embryo nesavčí účinky léků   MeSH
• endokrinní disruptory * toxicita   MeSH
• hormony štítné žlázy * metabolismus   MeSH
• oči účinky léků   MeSH
• resorcinoly * toxicita   MeSH
• thyroxin MeSH
• vzdušné vaky účinky léků   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• endokrinní disruptory * MeSH
• hormony štítné žlázy * MeSH
• resorcinol MeSH Prohlížeč
• resorcinoly * MeSH
• thyroxin MeSH

DNA damage in embryos shapes the development of an organism. Understanding life stage-specific differences between fish species is essential for ecological risk assessment measures. We explored DNA damage sensitivity in two nonmodel fish species, sterlet (Acipenser ruthenus) and common carp (Cyprinus carpio). Embryos of these species were exposed to a model genotoxicant, camptothecin (CPT), during cleavage (2-cell) stage and gastrulation. Results revealed a species-specific DNA damage sensitivity only at cleavage stage. 3 nM CPT caused lethality in sterlet embryos while carp embryos hatched normally. Multiple nuclear abnormalities were observed in sterlet embryos by early gastrula stage. However, carp embryos exhibited nuclear abnormalities and DNA fragmentation at neurula stage only when exposed to 7 nM CPT. Moreover, increased expression of tp53 in carp embryos at gastrula stage suggests activation of apoptosis mechanism. These findings suggest that carp embryos activate DNA damage response more efficiently than sterlet embryos at same developmental stage.

• Klíčová slova
• DNA repair, Development, Fish, Nuclear abnormality, Species-specific,
• MeSH
• apoptóza účinky léků   MeSH
• chemické látky znečišťující vodu toxicita   MeSH
• druhová specificita * MeSH
• embryo nesavčí * účinky léků   MeSH
• fragmentace DNA MeSH
• kamptothecin * toxicita   analogy a deriváty   MeSH
• kapři * embryologie   genetika   MeSH
• mutageny toxicita   MeSH
• nádorový supresorový protein p53 genetika   metabolismus   MeSH
• poškození DNA * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• kamptothecin * MeSH
• mutageny MeSH
• nádorový supresorový protein p53 MeSH

Personal Care Products (PCPs) have been one of the most studied chemicals in the last twenty years since they were identified as pseudo-persistent pollutants by the European Union in the early 2000s. The accumulation of PCPs in the aquatic environment and their effects on non-target species make it necessary to find new, less harmful, substances. Polyethylene glycol (PEGs) and polyvinyl alcohol (PVAs) are two polymers that have increased their presence in the composition of PCPs in recent years, but little is known about the effect of their accumulation in the environment on non-target species. Through embryotoxicity tests on two common models of aquatic organisms (Danio rerio and Xenopus laevis), this work aims to increase the knowledge of PEGs and PVAs' effects on non-target species. Animals were exposed to the pollutant for 96 h. The main embryotoxicity endpoint (mortality, hatching, malformations, heartbeat rate) was recorded every 24 h. The most significant results were hatching delay in Danio rerio exposed to both chemicals, in malformations (oedema, body malformations, changes in pigmentation and deformations of spine and tail) in D. rerio and X. laevis and significant change in the heartbeat rate (decrease or increase in the rate) in both animals for all chemicals tested.

• Klíčová slova
• Aquatic toxicity, Danio rerio, Emerging contaminants, Surface waters, Xenopus laevis,
• MeSH
• chemické látky znečišťující vodu * toxicita   MeSH
• dánio pruhované * MeSH
• embryo nesavčí * účinky léků   MeSH
• polyethylenglykoly * toxicita   MeSH
• polyvinylalkohol * toxicita   chemie   MeSH
• testy toxicity MeSH
• Xenopus laevis MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• polyethylenglykoly * MeSH
• polyvinylalkohol * MeSH

The Fish Embryo Acute Toxicity (FET) Test was adopted by the Organisation for Economic Co-operation and Development as OECD TG 236 in 2013. The test has been designed to determine acute toxicity of chemicals on embryonic stages of fish and proposed as an alternative method to the Fish Acute Toxicity Test performed according to OECD TG 203. In recent years fish embryos were used not only in the assessment of toxicity of chemicals but also for environmental and wastewater samples. In our study we investigated the acute toxicity of treated wastewater from seven hospitals in the Czech Republic. Our main purpose was to compare the suitability and sensitivity of zebrafish embryos with the sensitivity of two other aquatic organisms commonly used for wastewater testing - Daphnia magna and Aliivibrio fischeri. For the aim of this study, in addition to the lethal endpoints of the FET test, sublethal effects such as delayed heartbeat, lack of blood circulation, pericardial and yolk sac edema, spinal curvature and pigmentation failures were evaluated. The comparison of three species demonstrated that the sensitivity of zebrafish embryos is comparable or in some cases higher than the sensitivity of D. magna and A. fischeri. The inclusion of sublethal endpoints caused statistically significant increase of the FET test efficiency in the range of 1-12 %. Based on our results, the FET test, especially with the addition of sublethal effects evaluation, can be considered as a sufficiently sensitive and useful additional tool for ecotoxicity testing of the acute toxicity potential of hospital effluents.

• MeSH
• Aliivibrio fischeri účinky léků   MeSH
• časové faktory MeSH
• chemické látky znečišťující vodu toxicita   MeSH
• dánio pruhované embryologie   MeSH
• Daphnia účinky léků   MeSH
• embryo nesavčí účinky léků   MeSH
• hodnocení rizik MeSH
• LD50 MeSH
• monitorování životního prostředí * MeSH
• nemocnice * MeSH
• odpadní voda toxicita   MeSH
• reprodukovatelnost výsledků MeSH
• testy akutní toxicity * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• odpadní voda MeSH

DNA damage caused by exogenous or endogenous factors is a common challenge for developing fish embryos. DNA damage repair (DDR) pathways help organisms minimize adverse effects of DNA alterations. In terms of DNA repair mechanisms, sturgeons represent a particularly interesting model due to their exceptional genome plasticity. Sterlet (Acipenser ruthenus) is a relatively small species of sturgeon. The goal of this study was to assess the sensitivity of sterlet embryos to model genotoxicants (camptothecin, etoposide, and benzo[a]pyrene), and to assess DDR responses. We assessed the effects of genotoxicants on embryo survival, hatching rate, DNA fragmentation, gene expression, and phosphorylation of H2AX and ATM kinase. Exposure of sterlet embryos to 1 µM benzo[a]pyrene induced low levels of DNA damage accompanied by ATM phosphorylation and xpc gene expression. Conversely, 20 µM etoposide exposure induced DNA damage without activation of known DDR pathways. Effects of 10 nM camptothecin on embryo development were stage-specific, with early stages, before gastrulation, being most sensitive. Overall, this study provides foundational information for future investigation of sterlet DDR pathways.

• Klíčová slova
• ATM, DNA damage repair, H2AX, embryo, genotoxicity, sturgeon,
• MeSH
• benzopyren toxicita   MeSH
• embryo nesavčí účinky léků   embryologie   metabolismus   MeSH
• embryonální vývoj účinky léků   genetika   MeSH
• etoposid toxicita   MeSH
• fragmentace DNA účinky léků   MeSH
• kamptothecin toxicita   MeSH
• kometový test MeSH
• mutageny toxicita   MeSH
• oprava DNA * MeSH
• poškození DNA * MeSH
• ryby embryologie   genetika   MeSH
• testy genotoxicity metody   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• benzopyren MeSH
• etoposid MeSH
• kamptothecin MeSH
• mutageny MeSH

Cyanobacteria are known for their ability to produce and release mixtures of up to thousands of compounds into the environment. Recently, the production of novel metabolites, retinoids, was reported for some cyanobacterial species along with teratogenic effects of samples containing these compounds. Retinoids are natural endogenous substances derived from vitamin A that play a crucial role in early vertebrate development. Disruption of retinoid signalling- especially during the early development of the nervous system- might lead to major malfunctions and malformations. In this study, the toxicity of cyanobacterial biomass samples from the field containing retinoids was characterized by in vivo and in vitro bioassays with a focus on the potential hazards towards nervous system development and function. Additionally, in order to identify the compounds responsible for the observed in vitro and in vivo effects the complex cyanobacterial extracts were fractionated (C18 column, water-methanol gradient) and the twelve obtained fractions were tested in bioassays. In all bioassays, all-trans retinoic acid (ATRA) was tested along with the environmental samples as a positive control. Retinoid-like activity (mediated via the retinoic acid receptor, RAR) was measured in the transgenic cell line p19/A15. The in vitro assay showed retinoid-like activity by specific interaction with RAR for the biomass samples. Neurotoxic effects of selected samples were studied on zebrafish (Danio rerio) embryos using the light/dark transition test (Viewpoint, ZebraLab system) with 120 hpf larvae. In the behavioural assay, the cyanobacterial extracts caused significant hyperactivity in zebrafish at 120 hpf after acute exposure (3 h prior to the measurement) at concentrations below the teratogenicity LOEC (0.2 g dw L-1). Similar effect was observed after exposure to fractions of the extracts with detected retinoid-like activity and additive effect was observed after combining the fractions. However, the effect on behaviour was not observed after exposure to ATRA only. To provide additional insight into the behavioural effects and describe the underlying mechanism gene expression of selected biomarkers was measured. We evaluated an array of 28 genes related to general toxicity, neurodevelopment, retinoid and thyroid signalling. We detected several affected genes, most notably, the Cyp26 enzymes that control endogenous ATRA concentration, which documents an effect on retinoid signalling.

• Klíčová slova
• ATRA, Biomarkers, Cyanobacteria, Locomotor response, Retinoids, Zebrafish,
• MeSH
• biomasa MeSH
• biotest MeSH
• chemické látky znečišťující vodu metabolismus   toxicita   MeSH
• chování zvířat účinky léků   MeSH
• dánio pruhované růst a vývoj   metabolismus   MeSH
• embryo nesavčí účinky léků   metabolismus   MeSH
• exprese genu účinky léků   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• receptory kyseliny retinové genetika   metabolismus   MeSH
• sinice růst a vývoj   metabolismus   MeSH
• tretinoin metabolismus   toxicita   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• receptory kyseliny retinové MeSH
• tretinoin MeSH

An increase in the production and usage of gold nanoparticles (AuNPs) triggers the necessity to focus on their impact on ecosystems. Therefore, the purpose of this study was to investigate the acute toxicity of AuNPs and ionic gold (Au (III)) to organisms representing all trophic levels of the aquatic ecosystem, namely producers (duckweed Lemna minor), consumers (crustacean Daphnia magna, embryos of Danio rerio) and decomposers (bacteria Vibrio fischeri). The organisms were exposed according to a standardized protocol for each species and endpoints. The AuNPs (1.16 and 11.6 d.nm) were synthesized using citrate (CIT) and polyvinylpyrrolidone (PVP) as capping agents, respectively. It was found, that Au (III) was significantly more toxic than AuNPs PVP and AuNPs CIT. AuNPs showed significant toxicity only at high concentrations (mg/L), which are not environmentally relevant in the present time, but a cautious approach is advised, due to the possibility of interactions with other contaminants.

• Klíčová slova
• Danio rerio, Daphnia magna, Gold nanoparticles, Lemna minor, Vibrio fischeri,
• MeSH
• Aliivibrio fischeri účinky léků   MeSH
• Araceae účinky léků   MeSH
• dánio pruhované * MeSH
• Daphnia účinky léků   embryologie   MeSH
• embryo nesavčí účinky léků   MeSH
• ionty toxicita   MeSH
• kovové nanočástice toxicita   MeSH
• testy akutní toxicity MeSH
• vodní organismy MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zlato toxicita   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ionty MeSH
• zlato MeSH