Effects of short-chain chlorinated paraffins on the sexual reproduction of Brachionus calyciflorus: a populational and biomolecular study

peer reviewedShort- Chain Chlorinated Paraffins (SCCPs) are ubiquitous, persistent chemicals whose toxicity and potential impacts on aquatic ecosystems have been overlooked for many years. This study aims to determine the impact of these chemicals on rotifers. As sexual reproduction is often more sensitive to toxicants than amictic reproduction, this study focuses on endpoints describing sexual reproduction and on the impact on the gene expression of three receptors associated with reproduction: retinoid-x-receptor (rxr), retinoid activated receptor (rar) and Membrane-Associated Progesterone Receptor (mapr). Brachionus calyciflorus was exposed to environmental concentrations of SCCPs (10,100 and 1000 ng/L) and the impact on sexual reproduction (mixis rate, fertilization rate, resting egg production and viability, inter-generational effects) was assessed. Variations in the gene expressions of rxr, rar and mapr were also studied through RT-qPCR analysis. Our results show that SCCPs increase the mixis rate but decrease the fertilization rate, leading to unaltered resting egg production. Exposure to SCCPs also affected the mRNA levels of the studied receptors in ways which could be linked to observed changes in mixis and fertilization rates.Parachlorec