Effects of EE2 on infection response in largemouth bass

Recent surveys of largemouth bass (Micropterus salmoides) in the Potomac River basin have observed a high prevalence of intersex males (> 80%), indicative of exposure to estrogenic compounds. Furthermore, estrogenic activity has been measured at many sites. Increased prevalence of pathogens has also been observed, potentially due to reduced immune function caused by anthropogenic stressors. The goal of this study was to determine if exposure to 17-ethynylestradiol, a model estrogenic compound, alters the ability of juvenile largemouth bass to mount an appropriate immune response to subsequent infection. Following a 3 day exposure to EE2 (1 or 10 ng/l), fish were infected with Edwardsiella piscicida and monitored for mortality and growth. Liver and spleen samples were obtained at the end of the experiment for histology and RNASeq.