Kumar Gokhlesh, Sarker Subhodeep, Menanteau-Ledouble Simon, El-Matbouli Mansour
Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
Parasitol Res. 2015 Jun;114(6):2301-8. doi: 10.1007/s00436-015-4425-z. Epub 2015 Mar 20.
Tetracapsuloides bryosalmonae is an enigmatic endoparasite which causes proliferative kidney disease in various species of salmonids in Europe and North America. The life cycle of the European strain of T. bryosalmonae generally completes in an invertebrate host freshwater bryozoan and vertebrate host brown trout (Salmo trutta) Linnaeus, 1758. Little is known about the gene expression in the kidney of brown trout during the developmental stages of T. bryosalmonae. In the present study, quantitative real-time PCR was applied to quantify the target genes of interest in the kidney of brown trout at different time points of T. bryosalmonae development. PCR primers specific for target genes were designed and optimized, and their gene expression levels were quantified in the cDNA kidney samples using SYBR Green Supermix. Expression of Rab GDP dissociation inhibitor beta, integral membrane protein 2B, NADH dehydrogenase 1 beta subcomplex subunit 6, and 26S protease regulatory subunit S10B were upregulated significantly in infected brown trout, while the expression of the ferritin M middle subunit was downregulated significantly. These results suggest that host genes involved in cellular signal transduction, proteasomal activities, including membrane transporters and cellular iron storage, are differentially upregulated or downregulated in the kidney of brown trout during parasite development. The gene expression pattern of infected renal tissue may support the development of intraluminal sporogonic stages of T. bryosalmonae in the renal tubular lumen of brown trout which may facilitate the release of viable parasite spores to transmit to the invertebrate host bryozoan.
四极虫（Tetracapsuloides bryosalmonae）是一种神秘的内寄生虫，可在欧洲和北美的多种鲑科鱼类中引发增殖性肾病。欧洲株四极虫的生命周期通常在无脊椎动物宿主淡水苔藓虫和脊椎动物宿主褐鳟（Salmo trutta）（林奈，1758年）体内完成。关于四极虫发育阶段褐鳟肾脏中的基因表达情况，人们了解甚少。在本研究中，运用定量实时PCR技术，对四极虫发育不同时间点褐鳟肾脏中感兴趣的靶基因进行定量分析。针对靶基因设计并优化了PCR引物，使用SYBR Green Supermix对肾脏cDNA样本中的基因表达水平进行定量。在受感染的褐鳟中，Rab GDP解离抑制剂β、整合膜蛋白2B、NADH脱氢酶1β亚复合体亚基6和26S蛋白酶调节亚基S10B的表达显著上调，而铁蛋白M中间亚基的表达则显著下调。这些结果表明，在寄生虫发育过程中，褐鳟肾脏中参与细胞信号转导、蛋白酶体活性（包括膜转运蛋白和细胞铁储存）的宿主基因呈现出不同程度的上调或下调。受感染肾组织的基因表达模式可能支持四极虫在褐鳟肾小管腔内发育管腔内孢子生殖阶段，这可能有助于释放有活力的寄生虫孢子，从而传播到无脊椎动物宿主苔藓虫体内。
