Reproductive toxicity
Identification of reprotoxicity in transgenic medaka fish embryos
Reproductive toxicity can be described as negative impact of substances on the reproductive ability of organisms. The identification of reproductive toxicity is a primary goal during hazard assessment of substances. According to REACH, studies on reproductive toxicity are required for all substances produced in quantities above 10 t/a. Although a variety of reprotoxicity tests are available, only in vivo animal studies are currently accepted by the regulatory authorities. Fish embryo toxicity tests (FET) are the most advocated alternative to time-consuming and expensive animal testing in ecotoxicology and their application has focused on acute toxicity assessment. Further, fish embryos may serve as valuable model system in reproductive toxicity. We use transgenic lines of the small fresh water fish medaka (Oryzias latipes) to identify reproductive toxicants within the Fish Embryo Reproductive Toxicity Test (FERT).
Embryos of transgenic lines show vasa-driven EGFP or mRFP expression in primordial germ cells (PGC) and gonocytes enabling their quantification by fluorescence microscopy in vivo. We found concentration dependent effects on germ cell establishment and gonad colonization for known mammalian ovotoxicants. Our investigation highlights the possibility of using transgenic medaka embryos as tool to identify reproductive toxicity in vivo. This method could reduce the number of animal testing and provide information on how substances interfere with reproduction
vasa-driven fluorescence of reporter proteins expressed in germ cell of medaka embryos. Control embryos (left) are compared to embryos after exposure (right).
Former Project Team and Funding
Dr. Sabine Richter & Dr. Sophie Thalmann
The Project was supported by the Centre for Documentation and Evaluation of Alternatives to Animal Experiments (ZEBET) at the Federal Institute for Risk Assessment: 01.10.2013 - 30.09.2015