Morphological Score Assignment Guidelines for the Dechorionated Zebrafish Teratogenicity Assay

BACKGROUND: Recently we reported the development and optimization of a zebrafish teratogenicity assay using dechorionated AB strain embryos, a promising assay that was 87% concordant in correctly identifying in vivo teratogens and non-teratogens from a set of 31 compounds (Brannen et al., 2010: Birth Defects Res 89:66-77). METHODS: This assay utilizes a zebrafish morphological score system to characterize adverse effects and identify the no-observed-adverse-effect level (NOAEL). RESULTS: This report describes in detail the morphological score system used in the dechorionated zebrafish embryo culture teratogenicity assay. The morphological assessment includes evaluation of most structures and organ systems and grades relative severity of abnormalities. CONCLUSIONS: To this end, the morphological score system provides information of tissue-specific teratogenicity that has been found to have good concordance with structures found affected in vivo and can also be used to rank compounds based on the severity of malformations. Birth Defects Res (Part B) 89:382-395, 2010. (C) 2010 Wiley-Liss, Inc.