Reproductive axis gene regulation during photostimulation and photorefractoriness in Yangzhou goose ganders

作者：Huanxi Zhu, Zhe Chen, Xibin Shao, Jianning Yu, Chuankun Wei, Zichun Dai, Zhendan Shi · 发表于：Frontiers in Zoology · 年份：2017 · DOI：10.1186/s12983-017-0200-6 · 被引用次数：33 · 研究领域：Circadian rhythm and melatonin、Hypothalamic control of reproductive hormones、Reproductive biology and impacts on aquatic species

BACKGROUND: The Yangzhou goose is a long-day breeding bird that has been increasingly produced in China. Artificial lighting programs are used for controlling its reproductive activities. This study investigated the regulations of photostimulation and photorefractoriness that govern the onset and cessation of the breeding period. RESULTS: Increasing the daily photoperiod from 8 to 12 h rapidly stimulated testis development and increased plasma testosterone concentrations, with peak levels being reached 2 months after the photoperiod increase. Subsequently, testicular activities, testicular weight, spermatogenesis, and plasma testosterone concentrations declined steadily and reached to the nadir at 5 months after the 12-hour photoperiod. Throughout the experiment, plasma concentrations of triiodothyronine and thyroxine changed in reciprocal fashions to that of testosterone. The stimulation of reproductive activities caused by the increasing photoperiod was associated with increases in gonadotropin-releasing hormone (GnRH), but decreases in gonadotropin-inhibitory hormone (GnIH) and vasoactive intestinal peptide (VIP) gene messenger RNA (mRNA) levels in the hypothalamus. In the pituitary gland, the levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) mRNA abruptly increased during the longer 12-hour photoperiod. The occurrence of photorefractoriness was associated with increased GnIH gene transcription by over 250-fold, together with increased VIP mRNA leve...