Morphometric analysis in zebrafish embryos to predict teratogenicity and modes of action in mammals

Sergio Jarque, Rafael Miñana-Prieto, Valentina Schiavone, Jone Ibarra, María Rubio-Brotons, Víctor Ordóñez, Sylvia Dyballa and Javier Terriente. ZeClinics SL, Carretera de Can Ruti, Camí de les Escoles s/n, Edificio IGTP Muntanya, 08916, Badalona, Barcelona (SPAIN).


To answer the growing demand for a fast, reliable and cost-effective methodology to detect the chemical substances toxicity (particularly new drugs and medications in Human Risk Assessment), several laboratories across the world are joining forces to develop, standardize, harmonize and promote Zebrafish as a new test method. In this scenario, we are acting on several fronts: participating in a large number of global and multi-laboratories initiatives but also boosting our internal R&D in order to validate it as a preclinical alternative model and achieve soon the approval of international test guidelines.

In the project presented here, we exposed zebrafish embryos from 0 to 96 h post fertilization to a battery of 31 compounds classified as teratogens or non-teratogens in mammals to prove its predictivity. The teratogenicity score was based on the measurement of 16 phenotypic parameters, namely heart edema, pigmentation, body length, eye size, yolk size, yolk sac edema, otic vesicle defects, otoliths defects, body axis defects, developmental delay, tail bending, scoliosis, lateral fins absence, hatching ratio, lower jaw malformations and tissue necrosis, using a high throughput automated software. Among the 31 compounds, 20 were detected as teratogens and 11 as non-teratogens, resulting in 94.44 % sensitivity, 90.91 % specificity and 87.10 % accuracy compared to rodents. These percentages decreased slightly when referred to humans, with 87.50 % sensitivity, 81.82 % specificity and 74.19 % accuracy, but allowed an increase in the prediction levels reported by rodents for the same compounds. Positive compounds showed a high correlation among all teratogenic phenotypes, pointing out at general developmental delay as a major cause to explain the physiological/morphological malformations. A subsequent analysis based on deviations from main trends revealed potential specific modes of action for some compounds such as retinoic acid, DEAB, ochratoxin A, haloperidol, warfarin, valproic acid, acetaminophen, dasatinib, imatinib, dexamethasone, 6-aminonicotinamide and bisphenol A. The high degree of predictivity and the possibility of applying mechanistic approaches makes zebrafish a powerful model for screening teratogenicity.

Morphometric analysis in zebrafish embryos to predict teratogenicity and modes of action in mammals