TY - JOUR
T1 - High melatonin conditions by constant darkness and high temperature differently affect melatonin receptor mt1 and TREK channel trek2a in the brain of zebrafish
AU - Loganathan, Kavinash
AU - Moriya, Shogo
AU - Parhar, Ishwar S.
N1 - Funding Information:
We thank Dr. Tomoko Soga, Dr. Takashi Kitahashi, and Dr. Satoshi Ogawa for their constructive comments. This work was supported by grants from Monash University Malaysia (M-3-08 and TK-10-01).
Publisher Copyright:
© 2018, Mary Ann Liebert, Inc., publishers.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018/10
Y1 - 2018/10
N2 - Ambient light and temperature affect reproductive function by regulating kisspeptin and gonadotrophin-releasing hormone (GnRH) in vertebrates. Melatonin and melatonin receptors, as well as the two-pore domain K+ channel-related K+ (TREK) channels, are affected by light and/or temperature; therefore, these molecules could modulate kisspeptin and GnRH against ambient light and temperature. In this study, we investigated the effect of light and temperature, which affect melatonin levels in gene expression levels of TREK channels, kisspeptin, and GnRH. We first investigated the effects of different light and temperature conditions on brain melatonin concentrations by ELISA. Fish were exposed to either constant darkness, constant light, high temperature (35°C), or low temperature (20°C) for 72 h. Brain melatonin levels were significantly high under constant darkness and high temperature. We further investigated the effects of high brain melatonin levels by constant darkness and high temperature on gene expression levels of melatonin receptors (mt1, mt2, and mel1c), TREK channels (trek1b, trek2a, and trek2b), gnrh3, and kiss2 in the adult zebrafish brain by real-time polymerase chain reaction. Fish were exposed to constant darkness or elevated temperatures (35°C) for 72 h. trek2a, kiss2, and gnrh3 levels were increased under constant darkness. High temperature decreased gene expression levels of mt1, mt2, mel1c, and gnrh3 in the preoptic area, whereas other genes remained unchanged. Melatonin receptors, TREK channels, gnrh3, and kiss2 responded differently under high melatonin conditions. The melatonin receptors and the TREK channels could play roles in the regulation of reproduction by environmental cues, especially ambient light and temperature.
AB - Ambient light and temperature affect reproductive function by regulating kisspeptin and gonadotrophin-releasing hormone (GnRH) in vertebrates. Melatonin and melatonin receptors, as well as the two-pore domain K+ channel-related K+ (TREK) channels, are affected by light and/or temperature; therefore, these molecules could modulate kisspeptin and GnRH against ambient light and temperature. In this study, we investigated the effect of light and temperature, which affect melatonin levels in gene expression levels of TREK channels, kisspeptin, and GnRH. We first investigated the effects of different light and temperature conditions on brain melatonin concentrations by ELISA. Fish were exposed to either constant darkness, constant light, high temperature (35°C), or low temperature (20°C) for 72 h. Brain melatonin levels were significantly high under constant darkness and high temperature. We further investigated the effects of high brain melatonin levels by constant darkness and high temperature on gene expression levels of melatonin receptors (mt1, mt2, and mel1c), TREK channels (trek1b, trek2a, and trek2b), gnrh3, and kiss2 in the adult zebrafish brain by real-time polymerase chain reaction. Fish were exposed to constant darkness or elevated temperatures (35°C) for 72 h. trek2a, kiss2, and gnrh3 levels were increased under constant darkness. High temperature decreased gene expression levels of mt1, mt2, mel1c, and gnrh3 in the preoptic area, whereas other genes remained unchanged. Melatonin receptors, TREK channels, gnrh3, and kiss2 responded differently under high melatonin conditions. The melatonin receptors and the TREK channels could play roles in the regulation of reproduction by environmental cues, especially ambient light and temperature.
KW - constant darkness
KW - high temperature
KW - melatonin
KW - melatonin receptor
KW - reproduction
KW - TREK channel
UR - http://www.scopus.com/inward/record.url?scp=85054458915&partnerID=8YFLogxK
U2 - 10.1089/zeb.2018.1594
DO - 10.1089/zeb.2018.1594
M3 - Article
C2 - 30102584
AN - SCOPUS:85054458915
SN - 1545-8547
VL - 15
SP - 473
EP - 483
JO - Zebrafish
JF - Zebrafish
IS - 5
ER -