Abstract:
Enterocytozoon hepatopenaei (EHP) is a parasite in shrimp farming. EHP mainly parasitizes the hepatopancreas of shrimp, causing slow growth, which severely restricts the economic income of shrimp farmers. To explore the pathogenic mechanism of EHP, the host subcellular construction, molecular biological characteristics, and mitochondrial condition of Litopenaeus vannamei were identified using transmission electron microscopy (TEM), real-time qPCR, an enzyme assay, and flow cytometry. The results showed that EHP spores, approximately 1 μm in size, were located on the cytoplasm of the hepatopancreas. The number of mitochondria increased significantly, and mitochondria morphology showed a condensed state in the high-concentration EHP-infected shrimp by TEM observation. In addition, there were some changes in mitochondrial potential, but apoptosis was not significantly different in the infected shrimp. The qPCR results showed that the gene expression levels of hexokinase and pyruvate kinase related to energy metabolism were both upregulated in the diseased L. vannamei. Enzymatic activity showed hexokinase and lactate dehydrogenase were significantly increased in the shrimp infected with EHP, indicating EHP infection can increase the glycolysis process and decrease the oxidative phosphorylation process of L. vannamei. Previous transcriptomic data analysis results also support this conclusion.
摘要:
肝肠孢子虫(EHP)是虾养殖中的一种寄生虫。EHP主要寄生于虾的肝胰腺,导致生长缓慢,严重制约了虾农的经济收入。探讨EHP的致病机制,宿主亚细胞结构,分子生物学特征,并利用透射电镜(TEM)鉴定凡纳滨对虾的线粒体状况,实时qPCR,酶测定,和流式细胞术。结果表明,EHP孢子,尺寸约为1μm,位于肝胰腺的细胞质上。线粒体数量显著增加,通过TEM观察,高浓度EHP感染的对虾线粒体形态呈浓缩状态。此外,线粒体电位有一些变化,但感染虾的细胞凋亡没有显着差异。qPCR结果显示,与能量代谢相关的己糖激酶和丙酮酸激酶的基因表达水平在患病的南美白对虾中都上调。酶活性显示,在感染EHP的虾中,己糖激酶和乳酸脱氢酶显著增加,说明EHP感染可以增加凡纳滨对虾糖酵解过程,减少氧化磷酸化过程。先前的转录组数据分析结果也支持这一结论。