A Circannual Clock Drives Expression of Genes Central for Seasonal Reproduction
| Autor: | Paul Pévet, Cristina Sáenz de Miera, Stefanie Monecke, David G. Hazlerigg, Julien Bartzen-Sprauer, Marie-Pierre Laran-Chich, Valérie Simonneaux |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Photoperiod Period (gene) media_common.quotation_subject medicine.medical_treatment Adaptation Biological Pinealectomy Thyrotropin beta Subunit Biology General Biochemistry Genetics and Molecular Biology Body Temperature Melatonin Biological Clocks Pituitary Gland Anterior Cricetinae Internal medicine Testis medicine Animals media_common photoperiodism Kisspeptins Chronobiology Agricultural and Biological Sciences(all) Biochemistry Genetics and Molecular Biology(all) Reproduction Body Weight Organ Size Endocrinology Gene Expression Regulation Sex steroid Seasons Pars tuberalis General Agricultural and Biological Sciences medicine.drug |
| Zdroj: | Current Biology. 24:1500-1506 |
| ISSN: | 0960-9822 |
| DOI: | 10.1016/j.cub.2014.05.024 |
| Popis: | SummaryAnimals living in temperate zones anticipate seasonal environmental changes to adapt their biological functions, especially reproduction and metabolism. Two main physiological mechanisms have evolved for this adaptation: intrinsic long-term timing mechanisms with an oscillating period of approximately 1 year, driven by a circannual clock [1], and synchronization of biological rhythms to the sidereal year using day length (photoperiod) [2]. In mammals, the pineal hormone melatonin relays photoperiodic information to the hypothalamus to control seasonal physiology through well-defined mechanisms [3–6]. In contrast, little is known about how the circannual clock drives endogenous changes in seasonal functions. The aim of this study was to determine whether genes involved in photoperiodic time measurement (TSHβ and Dio2) and central control of reproduction (Rfrp and Kiss1) display circannual rhythms in expression under constant conditions. Male European hamsters, deprived of seasonal time cues by pinealectomy and maintenance in constant photoperiod, were selected when expressing a subjective summer or subjective winter state in their circannual cycle of body weight, temperature, and testicular size. TSHβ expression in the pars tuberalis (PT) displayed a robust circannual variation with highest level in the subjective summer state, which was positively correlated with hypothalamic Dio2 and Rfrp expression. The negative sex steroid feedback was found to act specifically on arcuate Kiss1 expression. Our findings reveal TSH as a circannual output of the PT, which in turn regulates hypothalamic neurons controlling reproductive activity. Therefore, both the circannual and the melatonin signals converge on PT TSHβ expression to synchronize seasonal biological activity. |
| Databáze: | OpenAIRE |
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