Vitellogenesis is a principal process during ovarian maturation in crustaceans. This process is negatively regulated by gonad-inhibiting hormone (GIH), a neuronal peptide hormone from eyestalks. However, the detailed mechanism through which GIH regulates Vg expression is still ambiguous. In this study, suppression subtractive hybridization (SSH) under specific GIH-knockdown condition was utilized to determine the expression of genes in the ovary that may act downstream of GIH to control vitellogenin synthesis in Penaeus monodon. The total of 102 and 82 positive clones of up-regulated and down-regulated genes in GIH- knockdown shrimp were identified from the forward and reverse SSH libraries, respectively. Determination of the expression profiles of these reproduction-related genes during ovarian development revealed that the expression of calreticulin (CALR) was significantly reduced in vitellogenic ovary suggesting its role in vitellogenesis. Suppression of CALR by specific dsRNA showed elevated vitellogenin (Vg) transcript level in the ovary at day 7 post-dsRNA injection. Since CALR can bind to steroid hormone receptors and prevents the binding of the receptor to its responsive element to regulate gene expression, it is possible that CALR is an inhibitory mediator of vitellogenin synthesis via steroidal pathway. Our results posted a possible novel pathway of GIH signaling that might interfere the steroid signaling cascade to mediate Vg synthesis in the shrimp.

卵黄形成是甲壳动物卵巢成熟过程中的主要过程。该过程受到性腺抑制激素（GIH）的负调控，该激素来自眼球。但是，GIH调节Vg表达的详细机制仍不清楚。在这项研究中，在特定的GIH敲低条件下，通过抑制消减杂交（SSH）来确定可能在GIH下游控制斑节对虾卵黄蛋白原合成的基因在卵巢中的表达。GIH中共有102个和82个上调和下调基因的阳性克隆-分别从正向和反向SSH库中识别出敲除虾。确定这些发育相关基因在卵巢发育过程中的表达谱表明，钙网蛋白（CALR）的表达在卵黄形成性卵巢中显着降低，表明其在卵黄发生中的作用。特异性dsRNA对CALR的抑制显示卵黄蛋白原（Vg）升高。）dsRNA注射后第7天卵巢的转录水平。由于CALR可以结合类固醇激素受体，并阻止受体与其响应元件的结合以调节基因表达，因此CALR可能是通过类固醇途径抑制卵黄蛋白原合成的介质。我们的结果表明，GIH信号传导可能是一条新颖的途径，该信号通路可能会干扰类固醇信号传导级联以介导虾中的Vg合成。