Ramírez Raúl, Bakke Tor A, Harris Philip D
Natural History Museum, Department of Research and Collections, University of Oslo, P.O. Box 1172, NO-0318 Oslo, Norway.
Natural History Museum, Department of Research and Collections, University of Oslo, P.O. Box 1172, NO-0318 Oslo, Norway.
Int J Parasitol. 2014 Jul;44(8):543-9. doi: 10.1016/j.ijpara.2014.04.003. Epub 2014 May 27.
Two Norwegian isolates of the monogenean Gyrodactylus salaris Malmberg, 1957 with identical cytochrome c oxidase subunit I barcodes from different hosts, show highly divergent biological and behavioural characteristics. The Lierelva parasite strain, typically infecting Atlantic salmon, Salmo salar L., grew exponentially on Atlantic salmon, but the Pålsbufjorden parasite strain, commonly infecting Arctic charr, Salvelinus alpinus L., grew slowly on both hosts and was non-pathogenic to Atlantic salmon. Both parasite strains reproduced successfully on Arctic charr, but the Atlantic salmon-infecting Lierelva strain grew faster on both hosts. Experiments with isolated worms revealed differences in reproductive rates which may account for the observed population differences. Atlantic salmon parasites consistently gave birth at an earlier age than the Arctic charr parasites, with the differential increasing from 1 day for the first birth up to 2-4 days for the third birth. Arctic charr-infecting parasites were more active on Atlantic salmon than salmon parasites on Arctic charr, a behavioural strategy leading to enhanced G. salaris mortality. Sequencing of 10 kb of nuclear genomic markers revealed only four single nucleotide polymorphisms, confirming that isolates of G. salaris with differences in fitness traits influencing establishment, fecundity and behaviour may be remarkably similar at a molecular level. The framework for reporting and control of G. salaris requires re-appraisal in light of the discovery of variants with such divergent biology.
1957年马尔姆贝格描述的单殖吸虫——鲑三代虫（Gyrodactylus salaris）的两个来自挪威的分离株，其细胞色素c氧化酶亚基I条形码相同，但来自不同宿主，它们表现出高度不同的生物学和行为特征。利勒尔瓦（Lierelva）寄生虫株通常感染大西洋鲑（Salmo salar L.），在大西洋鲑上呈指数增长，但帕斯布峡湾（Pålsbufjorden）寄生虫株通常感染北极红点鲑（Salvelinus alpinus L.），在两种宿主上生长缓慢，对大西洋鲑无致病性。两种寄生虫株在北极红点鲑上均成功繁殖，但感染大西洋鲑的利勒尔瓦株在两种宿主上生长得更快。对分离出的虫体进行的实验揭示了繁殖率的差异，这可能解释了观察到的种群差异。大西洋鲑寄生虫始终比北极红点鲑寄生虫更早产卵，差异从第一次产卵提前1天增加到第三次产卵提前2 - 4天。感染北极红点鲑的寄生虫在大西洋鲑上比感染鲑的寄生虫在北极红点鲑上更活跃，这种行为策略导致鲑三代虫死亡率增加。对10 kb核基因组标记进行测序仅发现了四个单核苷酸多态性，证实了在影响定殖、繁殖力和行为的适合度性状上存在差异的鲑三代虫分离株在分子水平上可能非常相似。鉴于发现了具有如此不同生物学特性的变体，鲑三代虫的报告和控制框架需要重新评估。
