Roles of the Circadian Clock in Ovarian Physiology and Pathology / 中国生物化学与分子生物学报

ABSTRACT

The circadian rhythm of mammals is a physiological phenomena that is about 24 hours produced by genetically encoded molecular clocks, making the physiological process of the body coordinated with the changes of the external environment, and it is a manifestation of adaptation to the environment. In mammals, reproductive physiology is regulated by the circadian clock. The expression of circadian clock genes has been observed in each tissue of the hypothalamic-pituitary-ovarian (HPO) axis, and the biological clock at all levels coordinates and synchronizes with each other to maintain normal reproductive behavior. The production, maintenance, and regulation of circadian rhythms depend on a chain of transcription-translation feedback loops (TTLs), which determine the cycle and amplitude of gene expression in each tissue of the HPO axis. The circadian clock of the ovary is regulated by theneuroendocrine regulation of suprachiasmatic nucleus of the hypothalamus, but it is autonomous. Circadian rhythm disruption caused by environmental factors can seriously impair female fertility and lead to a range of related ovarian diseases. In addition, the circadian clock is also closely related to ovarianaging. Based on existing research, this paper focuses on the mechanism of the circadian clock in ovarian follicular development, ovulation and steroid generation, as well as the latest research progress on the relationship between the circadian clock and ovarian aging. In addition, several common ovarian diseases with decreased fertility due to circadian clock disorders are described.