Disruption of the salmon reproductive endocrine axis through prolonged nutritional stress: Changes in circulating hormone levels and transcripts for ovarian genes involved in steroidogenesis and apoptosis

► Investigated the mechanism of fasting-induced atresia of salmon ovarian follicles. ► Fasting reduced plasma IGF1 and E2, and pituitary, but not plasma FSH. ► Fasting reduced ovarian transcripts for FSH receptor and steroidogenic proteins. ► Fasting elevated ovarian mRNAs for apoptosis-related genes relative to fed fish. ► Nutritional stress may induce follicular atresia via the apoptotic pathway.