Expression of the orexigenic peptide ghrelin and the type 1a growth hormone secretagogue receptor in sheep oocytes and pre-implantation embryos produced in vitro.
Expression of the orexigenic peptide ghrelin and the type 1a growth hormone secretagogue receptor in sheep oocytes and pre-implantation embryos produced in vitro.
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DOI：
10.1111/j.1439-0531.2008.01259.x
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发表时间：
2010-02
期刊：
影响因子：
--
通讯作者：
C. Du;H. Li;G. Cao;Xilingaowa;C. Wang;C. Li
中科院分区：
文献类型：
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作者：
C. Du;H. Li;G. Cao;Xilingaowa;C. Wang;C. Li
最近的研究表明ghrelin在生殖组织中的外周作用。在这里，我们提供的证据表明，生长激素释放肽及其受体GHSR-1a（1a型生长激素促分泌素受体）表达在mRNA和蛋白质水平在绵羊卵母细胞和植入前胚胎体外生产。实时RT-PCR实验证实，生长激素释放肽mRNA水平的变化取决于发育阶段，中期II（MII）的卵母细胞中的最高表达，在2细胞阶段的较高表达，和最小的表达在生发囊泡（GV）的卵母细胞，4-和8-细胞阶段，并在囊胚。GHSR-1a mRNA表达水平从GV期到MII期逐渐下降，在2-细胞期迅速上升，然后保持稳定，直至囊胚期。Ghrelin蛋白在内细胞团和滋养外胚层细胞中主要分布于细胞质中，而GHSR-1a蛋白在细胞膜中含量最高。总之，在绵羊卵母细胞和植入前胚胎的胃饥饿素信号系统的存在开辟了这种新的分子在生殖功能的潜在调节作用的可能性。
Recent studies have implicated the peripheral actions of ghrelin in reproductive tissues. Here, we provide evidence that both ghrelin and its receptor GHSR-1a (the type 1a growth hormone secretagogue receptor) are expressed at both mRNA and protein levels in sheep oocytes and pre-implantation embryos produced in vitro. Real-time RT-PCR experiments confirmed that ghrelin mRNA levels varied depending on developmental stage, with the highest expression in metaphase II (MII) oocytes, higher expression at the 2-cell stage, and minimal expression in germinal vesicle (GV) oocytes, 4- and 8-cell stages, and in the blastocyst. The levels of GHSR-1a mRNA decreased from GV to MII, increased immediately at the 2-cell stage and then remained stable until the blastocyst stage. Ghrelin protein was detected mainly in the cytoplasm close to the plasma membrane in both inner cell mass and trophectoderm cells, while GHSR-1a protein was most abundant in the plasma membrane. In conclusion, the presence of the ghrelin signalling system within the sheep oocytes and pre-implantation embryos opens up the possibility of a potential regulatory role of this novel molecule in reproductive function.