Leptin and ghrelin in anadromous Arctic charr: Cloning and change in expressions during a seasonal feeding cycle
Leptin and ghrelin in anadromous Arctic charr: Cloning and change in expressions during a seasonal feeding cycle
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DOI：
10.1016/j.ygcen.2009.06.010
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发表时间：
2010-01-01
影响因子：
2.7
通讯作者：
Kurokawa, Tadahide
中科院分区：
文献类型：
--
作者：
Froiland, Eirik;Murashita, Koji;Kurokawa, Tadahide
溯河产卵（海迁移）北极图（Salvelinus alpinus）显示明显的食物摄入量和生长的季节性变化，是一个有趣的模型，用于研究食欲调节机制。本研究克隆了北极黑鲈生长激素释放肽（ghrelin，GHRL）和瘦素（leptin，LEP）基因的cDNA，并采用qPCR方法检测了半野生溯河产卵北极黑鲈在季节性摄食周期中胃GHRL和肝LEP mRNA的表达。这些鱼是在夏季从海水中喂养回来后被捕获的，并被转移到一个室内水箱中，在那里它们被过量喂养，直到第二年10月。生长速率在冬末较低，在春末增加，并在夏季达到高峰，然后下降，在秋季，当鱼成为性成熟。生长率的变化与在每个采样日期进食的鱼的比例和全身脂质状态的相应变化有关。胃GHRL mRNA表达在冬末较高，在仲夏下降到最低点，并在初秋再次增加到较高水平。肝脏LEP mRNA在冬季，春季和初夏保持较低水平，之后逐渐增加，直到10月增加7倍。生长激素释放肽和瘦素的季节性变化支持这些激素在溯河产卵的北极图的能量稳态的长期调节中的作用。然而，不能排除秋季肝脏瘦素表达增加与性成熟有关。(C)2009 Elsevier Inc. All rights reserved.
Anadromous (sea-migrating) Arctic chart (Salvelinus alpinus) display pronounced seasonal variations in food intake and growth and is an interesting model for studying mechanisms of appetite regulation. In this study cDNAs encoding for ghrelin (GHRL) and leptin (LEP) in Arctic chart were cloned, after which stomach GHRL and liver LEP mRNA expressions were examined by qPCR during a seasonal feeding cycle of semi-wild anadromous Arctic chart. The fish were captured as they returned from summer feeding in seawater and transferred to an indoor tank where they were fed in excess until October the year after. Growth rate was low in late winter, increased in late spring and reached a peak during summer, and then declined during autumn, when the fish became sexually mature. The changes in growth rate were associated with corresponding changes in the proportion of fish that had been eating at each sampling date, and whole body lipid status. Stomach GHRL mRNA expression was high in late winter, decreased to a nadir in mid-summer and increased again to a high level in early autumn. Liver LEP mRNA remained low during winter, spring and early summer, after which there was a gradual, 7-fold increase until October. The seasonal changes in ghrelin and leptin support a role of these hormones in the long-term regulation of energy homeostasis in the anadromous Arctic chart. It cannot be excluded, however, that the increase in liver leptin expression during autumn is related to sexual maturation. (C) 2009 Elsevier Inc. All rights reserved.