Ozerov M Y, Lumme J, Päkk P, Rintamäki P, Zietara M S, Barskaya Y, Lebedeva D, Saadre E, Gross R, Primmer C R, Vasemägi A
Department of Biology, 20014, University of Turku, Finland.
Dis Aquat Organ. 2010 Sep 2;91(2):129-36. doi: 10.3354/dao02242.
We describe an unusually high infection rate of Gyrodactylus salaris Malmberg in juvenile Atlantic salmon Salmo salar L. of Baltic Sea origin, which are generally believed to be more resistant to G. salaris than East Atlantic salmon populations. Based on analyses of mitochondrial (complete cytochrome oxidase 1 [CO1] gene, 1548 bp) and nuclear (ADNAM1, 435 bp; internal transcribed spacer [ITS] rDNA region, 1232 bp) DNA fragments, the closest relatives of the characterized Estonian G. salaris strain were parasites found off the Swedish west coast and in Raasakka hatchery, Iijoki (Baltic Sea, Finland). Analyses of 14 microsatellite loci of the host S. salarrevealed that approximately 40% of studied fish were triploids. We subsequently identified triploid Atlantic salmon of Baltic origin as more susceptible to G. salaris infection than their diploid counterparts, possibly due to compromised complement-dependent immune pathways in triploid salmon. This is in accordance with earlier studies that have shown elevated susceptibility of triploids to various viral or bacterial pathogens, and represents one of the first reports of increased susceptibility of triploid salmonid fish to an ectoparasite. However, further experimental work is needed to determine whether triploid Atlantic salmon is generally more susceptible to G. salaris compared to their diploid counterparts, irrespective of the particular triploidization method and population of origin.
我们描述了波罗的海起源的大西洋鲑幼鱼中，鲑三代虫（Gyrodactylus salaris Malmberg）的感染率异常高，而人们通常认为这些幼鱼比东大西洋鲑种群对鲑三代虫更具抵抗力。基于对线粒体（完整细胞色素氧化酶1 [CO1] 基因，1548 bp）和核（ADNAM1，435 bp；内转录间隔区 [ITS] rDNA区域，1232 bp）DNA片段的分析，爱沙尼亚鲑三代虫菌株的最亲近亲属是在瑞典西海岸和芬兰伊若基（波罗的海）的拉萨克卡孵化场发现的寄生虫。对宿主大西洋鲑14个微卫星位点的分析表明，约40% 的研究鱼为三倍体。我们随后发现，波罗的海起源的三倍体大西洋鲑比其二倍体对应物更容易感染鲑三代虫，这可能是由于三倍体鲑鱼中补体依赖性免疫途径受损。这与早期研究结果一致，早期研究表明三倍体对各种病毒或细菌病原体的易感性增加，并且这是三倍体鲑科鱼类对外寄生虫易感性增加的首批报告之一。然而，需要进一步的实验工作来确定，无论采用何种特定的三倍体化方法和起源种群，三倍体大西洋鲑是否总体上比其二倍体对应物更容易感染鲑三代虫。
