Living organisms detect seasonal changes in day length (photoperiod), and alter their physiological functions accordingly, to fit seasonal environmental changes. This photoperiodic system is implicated in seasonal affective disorders and the season-associated symptoms observed in bipolar disease and schizophrenia. Thyroid-stimulating hormone beta subunit (Tshb), induced in the pars tuberalis (PT), plays a key role in the pathway that regulates animal photoperiodism. However, the upstream inducers of Tshb expression remain unknown. Here we show that late-night light stimulation acutely triggers the Eya3-Six1 pathway, which directly induces Tshb expression. Using melatonin-proficient CBA/N mice, which preserve the photoperiodic Tshb-expression response, we performed a genome-wide expression analysis of the PT under chronic short-day and long-day conditions. These data comprehensively identified long-day and short-day genes, and indicated that late-night light stimulation induces long-day genes. We verified this by advancing and extending the light period by 8 hours, which acutely induced Tshb expression, within one day. In a genome-wide expression analysis under this condition, we searched for candidate upstream genes by looking for expression that preceded Tshbs, and identified Eya3 gene. These results elucidate the comprehensive transcriptional photoperiodic response in the PT, revealing the complex regulation of Tshb expression and unexpectedly rapid response to light changes in the mammalian photoperiodic system.
Acute induction of Eya3 by late-night light stimulation triggers TSHβ expression in photoperiodism.
Sex, Age, Specimen part, Time
View SamplesThe adult mammalian brain is composed of distinct regions that have specialized roles. The BF/POA regions are thought to have an important role in the regulation of sleep/wake behavior. However, genetic markers of the responsible cells for the regulation of sleep/wake behavior are largely unknown. To identify the molecular markers of the BF/POA regions, we sampled the BF/POA regions and compared gene expression in the BF/POA regions with those of other brain regions which we previously reported in the BrainStars (B*) project, in which we sampled ~50 small brain regions, including sensory centers and centers for motion, time, memory, fear, and feeding.
Muscarinic Acetylcholine Receptors Chrm1 and Chrm3 Are Essential for REM Sleep.
Sex, Specimen part
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