Dyková Iva, Nowak Barbara, Pecková Hana, Fiala Ivan, Crosbie Philip, Dvoráková Helena
Biology Centre of the Academy of Sciences of the Czech Republic, Institute of Parasitology, Ceské Budĕjovice, Czech Republic.
Dis Aquat Organ. 2007 Feb 8;74(1):57-65. doi: 10.3354/dao074057.
We characterised 9 strains selected from primary isolates referable to Paramoeba/Neoparamoeba spp. Based on ultrastructural study, 5 strains isolated from fish (amoebic gill disease [AGD]-affected Atlantic salmon and dead southern bluefin tuna), 1 strain from netting of a floating sea cage and 3 strains isolated from invertebrates (sea urchins and crab) were assigned to the genus Neoparamoeba Page, 1987. Phylogenetic analyses based on SSU rDNA sequences revealed affiliations of newly introduced and previously analysed Neoparamoeba strains. Three strains from the invertebrates and 2 out of 3 strains from gills of southern bluefin tunas were members of the N. branchiphila clade, while the remaining, fish-isolated strains, as well as the fish cage strain, clustered within the clade of N. pemaquidensis. These findings and previous reports point to the possibility that N. pemaquidensis and N. branchiphila can affect both fish and invertebrates. A new potential fish host, southern bluefin tuna, was included in the list of farmed fish endangered by N. branchiphila. The sequence of P. eilhardi (Culture Collection of Algae and Protozoa [CCAP] strain 1560/2) appeared in all analyses among sequences of strain representatives of Neoparamoeba species, in a position well supported by bootstrap value, Bremer index and Bayesian posterior probability. Our research shows that isolation of additional strains from invertebrates and further analyses of relations between molecular data and morphological characters of the genera Paramoeba and Neoparamoeba are required. This complexity needs to be considered when attempting to define molecular markers for identification of Paramoeba/Neoparamoeba species in tissues of fish and invertebrates.
我们对从可归为副变形虫属/新副变形虫属物种的原始分离株中选出的9个菌株进行了特征描述。基于超微结构研究，从鱼类（受阿米巴鳃病[AGD]影响的大西洋鲑鱼和死亡的南部蓝鳍金枪鱼）分离出的5个菌株、从漂浮海上网箱中分离出的1个菌株以及从无脊椎动物（海胆和螃蟹）分离出的3个菌株被归为1987年命名的新副变形虫属。基于小亚基核糖体DNA（SSU rDNA）序列的系统发育分析揭示了新引入的和先前分析过的新副变形虫菌株之间的亲缘关系。来自无脊椎动物的3个菌株以及来自南部蓝鳍金枪鱼鳃的3个菌株中的2个属于嗜鳃新副变形虫分支，而其余从鱼类分离出的菌株以及网箱菌株则聚集在佩马奎德新副变形虫分支内。这些发现和先前的报告表明，佩马奎德新副变形虫和嗜鳃新副变形虫有可能同时影响鱼类和无脊椎动物。一种新的潜在鱼类宿主——南部蓝鳍金枪鱼，被列入受嗜鳃新副变形虫危害的养殖鱼类名单。在所有新副变形虫属菌株代表序列的分析中，艾氏副变形虫（藻类和原生动物培养保藏中心[CCAP]菌株1560/2）的序列出现在一个由自展值、布雷默指数和贝叶斯后验概率充分支持的位置。我们的研究表明，需要从无脊椎动物中分离更多菌株，并进一步分析副变形虫属和新副变形虫属的分子数据与形态特征之间的关系。在试图确定用于鉴定鱼类和无脊椎动物组织中副变形虫属/新副变形虫属物种的分子标记时，需要考虑这种复杂性。
