Endocrine Abstracts

Appropriate timing of various seasonal processes, such as reproduction, migration and hibernation, is crucial to the survival of animals living in temperate regions. Although this phenomenon has been studied for decades, the underlying mechanisms of seasonal changes in behavior are not well understood. Medaka fish (Oryzias latipes) are an excellent model for studying seasonal adaptation, as they are active and exhibit clear phototaxis in conditions simulating summer, ...

Animals living outside the tropics use changes in daylength to adapt to seasonal changes in environment, but the molecular and endocrine mechanisms underlying seasonal reproduction are not fully understood. The Japanese quail is a robust model for the study of these mechanisms because of its rapid and dramatic response to changes in photoperiod. In the previous study, we have demonstrated that local thyroid hormone catabolism within the mediobasal hypothalamus (MBH) by thyroid...

Seasonal reproduction enables animals outside tropical regions to rear offspring in a favourable environment. Increasing day length triggers a hypothalamic relay involving thyrotropin, the type 2 deiodinase enzyme and thyroid hormone, which activates the hypothalamic-pituitary-gonadal axis to induce reproductive competence. Photoperiod regulates calcium metabolism and the egg-laying cycle in the Japanese quail (Coturnix japonica), and we hypothesised that activity of ...

Seasonal reproduction enables animals outside tropical regions to rear offspring in a favourable environment. Increasing day length triggers a hypothalamic relay involving thyrotropin, the type 2 deiodinase enzyme and thyroid hormone, which activates the hypothalamic-pituitary-gonadal axis to induce reproductive competence. Photoperiod regulates calcium metabolism and the egg-laying cycle in the Japanese quail (Coturnix japonica), and we hypothesised that activity of ...