Eichner Christiane, Øvergård Aina-Cathrine, Nilsen Frank, Dalvin Sussie
SLCR-Sea Lice Research Centre, Department of Biology, University of Bergen, Thormøhlensgt. 55, 5008 Bergen, Norway.
SLCR-Sea Lice Research Centre, Institute of Marine Research, 5817 Bergen, Norway.
Exp Parasitol. 2015 Dec;159:79-93. doi: 10.1016/j.exppara.2015.09.001. Epub 2015 Sep 5.
The salmon louse (Lepeophtheirus salmonis) is a major parasite of salmonid fish in the marine environment. The interaction between the parasite and the host upon infection is not completely understood. However, it is clear that the parasite influences the host and its immune system. Prostaglandins produced by parasites such as flatworms, roundworms and ticks are documented or assumed to play a role in immunomodulation of the host. In the salmon louse, the effect of prostaglandins on the host is assumed, but remains to be documented. In this study, a salmon louse prostaglandin E2 synthase (LsPGES2) is characterized. Ontogenetic analysis showed that LsPGES2 is relatively stable expressed during development. The highest level of expression was seen in the free living stages, although elevated levels of LsPGES2 were also found in adult females. In copepodids, LsPGES2 is found around muscle cells, while it is observed in the reproductive organs of adult female lice. LsPGES2 expression was knocked-down by RNA interference in nauplii, but emerging copepodids did not display any changes in morphology nor ability to infect and develop to adult stages on fish. Additional knock-down of LsPGES2 in adult female lice did not produce any characteristic changes in phenotype nor reproductive output. It is concluded that under these experimental conditions, knock-down of LsPGES2 did not affect any essential functions of the salmon louse, neither in the free-living nor the parasitic stages.
鲑鱼虱（Lepeophtheirus salmonis）是海洋环境中鲑科鱼类的主要寄生虫。寄生虫与宿主在感染时的相互作用尚未完全了解。然而，很明显寄生虫会影响宿主及其免疫系统。扁虫、蛔虫和蜱等寄生虫产生的前列腺素已被证明或被认为在宿主的免疫调节中起作用。在鲑鱼虱中，前列腺素对宿主的影响是推测的，但仍有待证实。在本研究中，对鲑鱼虱前列腺素E2合酶（LsPGES2）进行了表征。个体发育分析表明，LsPGES2在发育过程中表达相对稳定。在自由生活阶段表达水平最高，尽管在成年雌性中也发现LsPGES2水平升高。在桡足幼体中，LsPGES2在肌肉细胞周围发现，而在成年雌性虱子的生殖器官中观察到。通过RNA干扰在无节幼体中敲低LsPGES2，但新出现的桡足幼体在形态上没有任何变化，也没有感染和发育到鱼类成年阶段的能力变化。在成年雌性虱子中进一步敲低LsPGES2，在表型或生殖输出方面没有产生任何特征性变化。得出的结论是，在这些实验条件下，敲低LsPGES2不会影响鲑鱼虱在自由生活阶段和寄生阶段的任何基本功能。
