Advancing the ecotoxicological relevancy of zebrafish : application of early-juvenile 20dpfZF to assess xenoestrogenicity of environmental chemicals and samples

Use of Early Juvenile Zebrafish Danio Rerio for In-Vivo Assessment of Endocrine Modulation by Xenoestrogens

Reliable and cost-effective early-life stage (ELS) bioassays incorporating practical experimentation without compromising scientific relevance are crucial in chemical risk assessment. This study investigated the use of 20 days- post-fertilization life stage ( 20dpfZF ) of zebrafish Danio rerio to screen environmental chemicals known to be estrogenic in adult fish. Firstly, studies with key genes in steroidogenesis were conducted; the brain isoform of aromatase gene ( cyp19a1b ) being the most prominently expressed biomarker. Regulation of mRNA levels of molecular biomarkers, vitellogenin 1 gene ( vtg1) and cyp19a1b were selected to assess the endocrine modulation by xenoestrogens, 17α-ethin…