Estrogen and xenoestrogen modulated transcriptome in the pituitary of juvenile female Atlantic cod (Gadus morhua)

Estrogens regulate many reproductive processes in fish and other vertebrates. In fish, the pituitary and liver are among the main sites of action of estrogens in the reproductive brain-pituitary-gonadal-hepatic axis. Environmental contaminants with estrogenic compounds acting at these organs have the potential to interfere with the reproductive processes in fish. In this work, RNA-seq analysis was performed to map estrogen and xenoestrogen target genes in the juvenile female Atlantic cod (Gadus morhua) after 72 h exposure to estrogenic compounds ethynylestradiol (EE2), and the xenoestrogens bisphenol A (BPA) and methoxychlor (MXC). Our results show that, in the pituitary, EE2 and the xenoestrogens modulated many genes and pathways related to reproduction (such as hormone synthesis, hormonal signaling), metabolic homeostasis, and cell differentiation and proliferation. The xenoestrogens BPA and MXC had similar effect as EE2 on the top differentially expressed genes, suggesting their potential to disrupt pituitary functions.