Changes in the expression of pituitary gonadotropin subunits during reproductive cycle of multiple spawning female chub mackerel Scomber japonicus
Changes in the expression of pituitary gonadotropin subunits during reproductive cycle of multiple spawning female chub mackerel Scomber japonicus
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DOI：
10.1007/s10695-011-9576-y
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发表时间：
2012-06-01
影响因子：
2.9
通讯作者：
Matsuyama, Michiya
中科院分区：
文献类型：
--
作者：
Nyuji, Mitsuo;Selvaraj, Sethu;Matsuyama, Michiya
生殖的内分泌调节在一个多产卵鱼与一个多型卵巢仍然在很大程度上未知。本研究的目的是监测在雌性鲭鱼的生殖周期中的三个促性腺激素（GtH）亚基（GP α，FSH β和LH β）的mRNA表达的变化。克隆和序列分析表明，鲭鱼GP α、FSH β和LH β的cDNA分别为658、535和599个核苷酸，分别编码117、115和147个氨基酸。我们应用定量实时PCR测定来定量这些GtH亚基的mRNA表达水平。在季节性生殖周期中，FSH β mRNA水平在卵黄发生阶段保持较高水平，而GP α和LH β mRNA水平在卵黄发生结束时达到峰值。GtH三个亚基的表达在产卵后下降。这些结果表明，卵泡刺激素（FSH）参与卵黄发生，而黄体生成素（LH）的功能在最终卵母细胞成熟（FOM）。GP α和FSH β mRNA水平在产卵周期的FOM阶段保持较高水平，并在产卵后进一步增加。因此，FSH的合成可能在产卵后被强烈激活，以加速卵黄发生，为下一次产卵做准备。或者，LH β mRNA水平在水合过程中下降，然后在排卵后增加。这项研究表明，鲭鱼是一个很好的模型，调查GtH功能在多产卵鱼。
The endocrine regulation of reproduction in a multiple spawning fish with an asynchronous-type ovary remains largely unknown. The objectives of this study were to monitor changes in the mRNA expression of three gonadotropin (GtH) subunits (GP alpha, FSH beta, and LH beta) during the reproductive cycle of the female chub mackerel . Cloning and subsequent sequence analysis revealed that the cDNAs of chub mackerel GP alpha, FSH beta, and LH beta were 658, 535, and 599 nucleotides in length and encoded 117, 115, and 147 amino acids, respectively. We applied a quantitative real-time PCR assay to quantify the mRNA expression levels of these GtH subunits. During the seasonal reproductive cycle, FSH beta mRNA levels remained high during the vitellogenic stages, while GP alpha and LH beta mRNA levels peaked at the end of vitellogenesis. The expression of all three GtH subunits decreased during the post-spawning period. These results suggest that follicle-stimulating hormone (FSH) is involved in vitellogenesis, while luteinizing hormone (LH) functions during final oocyte maturation (FOM). Both GP alpha and FSH beta mRNA levels remained high during the FOM stages of the spawning cycle and increased further just after spawning. Thus, FSH synthesis may be strongly activated just after spawning to accelerate vitellogenesis in preparation for the next spawning. Alternatively, LH beta mRNA levels declined during hydration and then increased after ovulation. This study demonstrates that chub mackerel are a good model for investigating GtH functions in multiple spawning fish.