Flusilazole induces spatio-temporal expression patterns of retinoic acid-, differentiation- and sterol biosynthesis-related genes in the rat Whole Embryo Culture

<p>Embryotoxic responses are critically dependent on the timing of exposure during embryo development. Here, we examined the time- dependent developmental effects in rat embryos exposed to flusilazole (FLU), and their link to retinoic acid (RA) mediated pathways. To this end, we assessed the effects of 4. h exposure of rat embryos in vitro to 300. μM FLU during four developmental time windows (0-4, 4-8, 24-28 and 44-48. h), evaluating morphological parameters, expression and localization of five genes directly or indirectly linked with the RA pathway. These were RA- (Cyp26a1 and Dhrs3), differentiation- (Gbx2 and Cdx1) and sterol biosynthesis- (Cyp51) related genes. Extended exposure for 48. h to 300. μM FLU resulted in morphological changes, typical for triazoles and RA, while the 4. h exposure times did not. Time dependent significant upregulation of the five selected genes was observed. These results corroborate that the embryotoxic responses to FLU are correlated with the regulation of the RA pathway. Thus, these gene expression markers can be considered early biomarkers of FLU-induced potential developmental toxicity later in the development.