TY - JOUR
T1 - Melatonin receptor mRNA localization and rhythmicity in the retina of the domestic chick, Gallus domesticus
AU - Natesan, Arjun K.
AU - Cassone, Vincent M.
PY - 2002/5
Y1 - 2002/5
N2 - The indoleamine hormone melatonin is synthesized and released by photoreceptors during the night within the chick retina, and confers timing information to modulate retinal physiology. Three subtypes of melatonin receptor with nearly identical pharmacological profiles have been described in chickens and are present in the retina. In this study, the spatial localization and temporal pattern of the mRNA for each of these receptors within the retina are described. The localization and rhythmicity of receptor mRNA were analyzed using in situ hybridization and RNase protection assay, respectively, with probes against specific nucleotide sequences encoding these receptors. Mel1A and Mel1C receptor mRNA have similar patterns of expression, primarily in the inner segments of photoreceptors, vitread portion of the inner nuclear layer, and in the retinal ganglion cell layer. Mel1B receptor mRNA is expressed at higher levels in the retina, with expression in photoreceptors, throughout the inner nuclear layer, and in the ganglion cell layer. Mel1A receptor mRNA is rhythmic in both light:dark (LD) cycles and in constant darkness (DD); Mel1A peaks during midday and mid-subjective day, respectively. Mel1C receptor mRNA is also rhythmically expressed in LD, but with a lower amplitude, such that transcript is high during the day and low during the night. In DD, Mel1C rhythms become 180 deg out of phase with a slight increase at night. Mel1B mRNA expression was highly variable and arrhythmic.
AB - The indoleamine hormone melatonin is synthesized and released by photoreceptors during the night within the chick retina, and confers timing information to modulate retinal physiology. Three subtypes of melatonin receptor with nearly identical pharmacological profiles have been described in chickens and are present in the retina. In this study, the spatial localization and temporal pattern of the mRNA for each of these receptors within the retina are described. The localization and rhythmicity of receptor mRNA were analyzed using in situ hybridization and RNase protection assay, respectively, with probes against specific nucleotide sequences encoding these receptors. Mel1A and Mel1C receptor mRNA have similar patterns of expression, primarily in the inner segments of photoreceptors, vitread portion of the inner nuclear layer, and in the retinal ganglion cell layer. Mel1B receptor mRNA is expressed at higher levels in the retina, with expression in photoreceptors, throughout the inner nuclear layer, and in the ganglion cell layer. Mel1A receptor mRNA is rhythmic in both light:dark (LD) cycles and in constant darkness (DD); Mel1A peaks during midday and mid-subjective day, respectively. Mel1C receptor mRNA is also rhythmically expressed in LD, but with a lower amplitude, such that transcript is high during the day and low during the night. In DD, Mel1C rhythms become 180 deg out of phase with a slight increase at night. Mel1B mRNA expression was highly variable and arrhythmic.
KW - Circadian
KW - Ganglion cells
KW - Mel
KW - Mel
KW - Mel
KW - Photoreceptors
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U2 - 10.1017/S0952523802192042
DO - 10.1017/S0952523802192042
M3 - Article
C2 - 12392176
AN - SCOPUS:0036591088
SN - 0952-5238
VL - 19
SP - 265
EP - 274
JO - Visual Neuroscience
JF - Visual Neuroscience
IS - 3
ER -