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RESEARCH PRODUCT

Circadian gene expression patterns of melanopsin and pinopsin in the chick pineal gland

Heike HolthuesRainer SpessertLutz VollrathLydia Engel

subject

Melanopsinmedicine.medical_specialtyLightPhotoperiodCircadian clockBiophysicsNerve Tissue ProteinsBiologyPineal GlandBiochemistryAvian ProteinsPineal glandInternal medicineGene expressionmedicineAnimalsPhotopigmentCircadian rhythmMolecular BiologyCells CulturedRegulation of gene expressionAdaptation OcularRod OpsinsCell BiologyCircadian Rhythmmedicine.anatomical_structureEndocrinologyAnimals NewbornGene Expression RegulationLight effects on circadian rhythmsense organsChickens

description

The directly light-sensitive chick pineal gland contains at least two photopigments. Pinopsin seems to mediate the acute inhibitory effect of light on melatonin synthesis, whereas melanopsin may act by phase-shifting the intrapineal circadian clock. In the present study we have investigated, by means of quantitative RT-PCR, the daily rhythm of photopigment gene expression as monitored by mRNA levels. Under a 12-h light/12-h dark cycle, the mRNA levels of both pigments were 5-fold higher in the transitional phase from light to dark than at night, both in vivo and in vitro. Under constant darkness in vivo and in vitro, the peak of pinopsin mRNA levels was attenuated, whereas that of melanopsin was not. Thus, whereas the daily rhythm of pinopsin gene expression is dually regulated by light plus the intrapineal circadian oscillator, that of melanopsin appears to depend solely on the oscillator.

yearjournalcountryeditionlanguage
2004-10-27Biochemical and Biophysical Research Communications
https://doi.org/10.1016/j.bbrc.2004.11.022