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Arch Toxicol
2022 Oct 24;9610:2815-2824. doi: 10.1007/s00204-022-03327-w.
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Predictive assays for craniofacial malformations: evaluation in Xenopus laevis embryos exposed to triadimefon.
Battistoni M
,
Metruccio F
,
Di Renzo F
,
Bacchetta R
,
Menegola E
.
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Craniofacial defects are one of the most frequent abnormalities at birth, but their experimental evaluation in animal models requires complex procedures. The aim of the present work is the comparison of different methodologies to identify dose- and stage-related craniofacial malformations in Xenopus laevis assay (R-FETAX, where the full cartilage evaluation, including flat mount technique, is the gold standard for skeletal defect detection). Different methods (external morphological evaluation of fresh samples, deglutition test, whole mount cartilage evaluation and Meckel-palatoquadrate angle measurements) were applied. Triadimefon (FON) was selected as the causative molecule as it is known to induce craniofacial defects in different animal models, including the amphibian X. laevis.FON exposure (0-31.25 μM) was scheduled to cover the whole 6-day test (from gastrula to free swimming tadpole stage) or each crucial developmental phases: gastrula, neurula, early morphogenesis, late morphogenesis, tadpole. Dose-dependent effects (fusions among craniofacial cartilages) were evident for groups exposed during the morphogenetic periods (neurula, early morphogenesis, late morphogenesis); gastrula was insensitive to the tested concentrations, tadpole group showed malformations only at 31.25 μM. The overall NOAEL was set at 3.9 μM. Results were evaluated applying benchmark dose (BMD) approach. The comparison of relative potencies from different methods showed deglutition as the only assay comparable with the gold standard (cartilage full evaluation).In conclusion, we suggest deglutition test as a reliable method for a rapid screening of craniofacial abnormalities in the alternative model X. laevis. This is a rapid, inexpensive and vital test allowing to preserve samples for the application of further morphological or molecular investigations.
Figure 1. R-FETAX experimental approach. The classical FETAX exposure (1) covers the entire test. R-FETAX windowed approach, by contrast, provides limited times of exposure, corresponding to the main developmental phases: 2 = pre-organogenetic period (midblastula-gastrula); 3 = early organogenetic period (from neurula till phylotypic stages; the striped red area corresponds to neurula); 4 = late organogenetic period (from phylotipic stages till tadpole); 5 = tadpole (very late organogenesis and functional differentiation)
Figure 2. Whole mount alcian blue-stained craniofacial cartilages (ventral view), allowing to detect cartilaginous elements in a normal larva (A) and in an abnormal sample (B) characterized by circular funnel-shaped fused cartilages (*). G = gill basket; I = intestine with degl + (A) and degl− (B) phenotypes (respectively, presence/absence of red microplastics in the intestine). In A, dotted lines indicate the M–PQ angle measurement
Figure 3. Appearance of whole mount (A, C, E) and flat mount (B, D, F) stained cartilages in a normal larva (A, B) and in larvae appearing as normal at the whole mount evaluation (C, E) showing moderate (D) or extended (F) fusions among ethmoidal (Eth), Meckel’s (M) and palatoquadrate (PQ) cartilages. In B note the articular space (arrow) between Meckel’s and palatoquadrate cartilages, not visible in the abnormal larvae (D, F). CH = ceratohyal cartilage
Figure 5. Hill model: dose–response curves obtained considering stage as covariate. The colors/symbols in the plot refer to the different exposure groups: black/upward triangle = classical FETAX exposure; green/diamond = gastrula; light blue/cross-square = neurula; red/ cross = early morphogenesis; dark blue/downward triangle = late morphogenesis; pink/cross-plus tadpole. Model evidenced late morphogenesis as the sensible subgroup
Figure 6. Lateral view of the anterior region of a normal larva (upper panel) with degl + phenotype and of an abnormal sample (lower panel) characterized by round head with bent encephalon (arrow), short snout (#) and degl− phenothype. I = intestine; * = normal linear encephalon
Baltzinger,
Hoxa2 knockdown in Xenopus results in hyoid to mandibular homeosis.
2005, Pubmed,
Xenbase
Baltzinger,
Hoxa2 knockdown in Xenopus results in hyoid to mandibular homeosis.
2005,
Pubmed
,
Xenbase
Battistoni,
Effect of nano-encapsulation of β-carotene on Xenopus laevis embryos development (FETAX).
2020,
Pubmed
,
Xenbase
Battistoni,
Modified Xenopus laevis approach (R-FETAX) as an alternative test for the evaluation of foetal valproate spectrum disorder.
2022,
Pubmed
,
Xenbase
Davis,
Introduction to benchmark dose methods and U.S. EPA's benchmark dose software (BMDS) version 2.1.1.
2011,
Pubmed
Di Renzo,
Antifungal triazole derivative triadimefon induces ectopic maxillary cartilage by altering the morphogenesis of the first branchial arch.
2007,
Pubmed
Di Renzo,
Is the amphibian X. laevis WEC a good alternative method to rodent WEC teratogenicity assay? The example of the three triazole derivative fungicides Triadimefon, Tebuconazole, Cyproconazole.
2011,
Pubmed
,
Xenbase
Di Renzo,
The agrochemical fungicide triadimefon induces abnormalities in Xenopus laevis embryos.
2011,
Pubmed
,
Xenbase
Di Renzo,
Stage-dependent abnormalities induced by the fungicide triadimefon in the mouse.
2011,
Pubmed
Di Renzo,
Early genetic control of craniofacial development is affected by the in vitro exposure of rat embryos to the fungicide triadimefon.
2011,
Pubmed
Di Renzo,
Expression analysis of some genes regulated by retinoic acid in controls and triadimefon-exposed embryos: is the amphibian Xenopus laevis a suitable model for gene-based comparative teratology?
2011,
Pubmed
,
Xenbase
Dubey,
Modeling human craniofacial disorders in Xenopus.
2017,
Pubmed
,
Xenbase
Filipsson,
The benchmark dose method--review of available models, and recommendations for application in health risk assessment.
2003,
Pubmed
Groppelli,
Teratogenic effects of two antifungal triazoles, triadimefon and triadimenol, on Xenopus laevis development: craniofacial defects.
2005,
Pubmed
,
Xenbase
Hallgrímsson,
Automated syndrome diagnosis by three-dimensional facial imaging.
2020,
Pubmed
Hardy,
Update: use of the benchmark dose approach in risk assessment.
2017,
Pubmed
Heusinkveld,
Distinguishing mode of action of compounds inducing craniofacial malformations in zebrafish embryos to support dose-response modeling in combined exposures.
2020,
Pubmed
Huang,
Impact of environmental chemicals on craniofacial skeletal development: Insights from investigations using zebrafish embryos.
2021,
Pubmed
Kennedy,
E-cigarette aerosol exposure can cause craniofacial defects in Xenopus laevis embryos and mammalian neural crest cells.
2017,
Pubmed
,
Xenbase
Menegola,
Comparative study of sodium valproate-induced skeletal malformations using single or double staining methods.
2002,
Pubmed
Menegola,
Craniofacial and axial skeletal defects induced by the fungicide triadimefon in the mouse.
2005,
Pubmed
Menegola,
An adverse outcome pathway on the disruption of retinoic acid metabolism leading to developmental craniofacial defects.
2021,
Pubmed
Mossey,
Cleft lip and palate.
2009,
Pubmed
Papis,
Gene expression in Xenopus laevis embryos after Triadimefon exposure.
2007,
Pubmed
,
Xenbase
Pasqualetti,
Ectopic Hoxa2 induction after neural crest migration results in homeosis of jaw elements in Xenopus.
2000,
Pubmed
,
Xenbase
Spokony,
The transcription factor Sox9 is required for cranial neural crest development in Xenopus.
2002,
Pubmed
,
Xenbase
Staal,
Head skeleton malformations in zebrafish (Danio rerio) to assess adverse effects of mixtures of compounds.
2018,
Pubmed
Xu,
Developmental toxicity of dibutyl phthalate and citrate ester plasticizers in Xenopus laevis embryos.
2018,
Pubmed
,
Xenbase
Zoupa,
Zebrafish as an Alternative Vertebrate Model for Investigating Developmental Toxicity-The Triadimefon Example.
2017,
Pubmed
Zoupa,
Dose addition in chemical mixtures inducing craniofacial malformations in zebrafish (Danio rerio) embryos.
2020,
Pubmed
