Hou Fujun, Gao Tiantian, Liu Tao, Jia Zhiying, Liu Yongjie, Sun Chengbo, Liu Xiaolin
College of Animal Science and Technology, Northwest A&F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Yangling 712100, China.
Fisheries College, Guangdong Ocean University, Guangdong 524088, China.
Fish Shellfish Immunol. 2016 Nov;58:436-441. doi: 10.1016/j.fsi.2016.09.032. Epub 2016 Sep 16.
Fibrinogen-related proteins (FREPs) are widely distributed in vertebrates and invertebrates and known having Fibrinogen-related domains (FReDs) which function in multiple aspects, especially in innate immune response as pattern recognition receptors. However, there is no any report about FREP in penaeid shrimp Litopenaeus vannamei. Here, totally 10 transcripts of FREP were isolated and named LvFREP1.1, 1.2 until 1.10. All of the 10 transcripts have high identity in their 3' ends and encode conserved FReDs. Since the 10 transcripts are highly similar we could not design any primers that can amplify a single transcript. We chose a pair of primers corresponding to part of LvFREP1.1 and LvFREP1.5 to examine their expression. Tissue distribution indicated LvFREP1.1 and LvFREP1.5 mRNA locates in hemocytes, gills, intestine, hearts and slightly in nerve. The expression of LvFREP1.1 and LvFREP1.5 behaves differently post bacteria and virus infection. Besides, recombinant LvFReD could agglutinate bacteria Vibrio harveyi in the presence of Ca. These initial data presents the diversity of FREPs in penaeid shrimp and also push us to further explore their roles in shrimp immune response.
纤维蛋白原相关蛋白（FREPs）广泛分布于脊椎动物和无脊椎动物中，已知其具有纤维蛋白原相关结构域（FReDs），这些结构域在多个方面发挥作用，尤其是在作为模式识别受体的先天免疫反应中。然而，关于凡纳滨对虾中FREP尚无任何报道。在此，共分离出10个FREP转录本，并命名为LvFREP1.1、1.2直至1.10。这10个转录本在其3'端具有高度同一性，并编码保守的FReDs。由于这10个转录本高度相似，我们无法设计出能扩增单个转录本的引物。我们选择了一对对应于LvFREP1.1和LvFREP1.5部分序列的引物来检测它们的表达。组织分布表明，LvFREP1.1和LvFREP1.5 mRNA定位于血细胞、鳃、肠、心脏，在神经中也有少量表达。LvFREP1.1和LvFREP1.5在细菌和病毒感染后的表达表现不同。此外，重组LvFReD在有钙离子存在的情况下能够凝集哈维氏弧菌。这些初步数据展示了对虾中FREPs的多样性，也促使我们进一步探索它们在对虾免疫反应中的作用。
