Jeffries Ken M, Hinch Scott G, Gale Marika Kirstin, Clark Timothy D, Lotto Andrew G, Casselman Matthew T, Li Shaorong, Rechisky Erin L, Porter Aswea D, Welch David W, Miller Kristina M
Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada.
Mol Ecol. 2014 Dec;23(23):5803-15. doi: 10.1111/mec.12980. Epub 2014 Nov 21.
We present the first data to link physiological responses and pathogen presence with subsequent fate during migration of wild salmonid smolts. We tagged and non-lethally sampled gill tissue from sockeye salmon (Oncorhynchus nerka) smolts as they left their nursery lake (Chilko Lake, BC, Canada) to compare gene expression profiles and freshwater pathogen loads with migration success over the first ~1150 km of their migration to the North Pacific Ocean using acoustic telemetry. Fifteen per cent of smolts were never detected again after release, and these fish had gene expression profiles consistent with an immune response to one or more viral pathogens compared with fish that survived their freshwater migration. Among the significantly upregulated genes of the fish that were never detected postrelease were MX (interferon-induced GTP-binding protein Mx) and STAT1 (signal transducer and activator of transcription 1-alpha/beta), which are characteristic of a type I interferon response to viral pathogens. The most commonly detected pathogen in the smolts leaving the nursery lake was infectious haematopoietic necrosis virus (IHNV). Collectively, these data show that some of the fish assumed to have died after leaving the nursery lake appeared to be responding to one or more viral pathogens and had elevated stress levels that could have contributed to some of the mortality shortly after release. We present the first evidence that changes in gene expression may be predictive of some of the freshwater migration mortality in wild salmonid smolts.
我们提供了首批数据，将野生鲑科幼鱼洄游期间的生理反应、病原体存在情况与后续命运联系起来。当红大马哈鱼（Oncorhynchus nerka）幼鱼离开它们的育幼湖（加拿大不列颠哥伦比亚省奇尔科湖）时，我们对其进行标记并对鳃组织进行非致死性采样，以使用声学遥测技术比较基因表达谱和淡水病原体负荷与它们向太平洋北部洄游的前约1150公里的洄游成功率。15%的幼鱼放流后再也没有被检测到，与在淡水洄游中存活下来的鱼相比，这些鱼的基因表达谱与对一种或多种病毒病原体的免疫反应一致。放流后未被检测到的鱼中显著上调的基因包括MX（干扰素诱导的GTP结合蛋白Mx）和STAT1（信号转导和转录激活因子1-α/β），它们是对病毒病原体的I型干扰素反应的特征。离开育幼湖的幼鱼中最常检测到的病原体是传染性造血坏死病毒（IHNV）。总体而言，这些数据表明，一些被认为在离开育幼湖后死亡的鱼似乎正在对一种或多种病毒病原体作出反应，并且应激水平升高，这可能导致了放流后不久的部分死亡。我们提供了首个证据，即基因表达的变化可能预示着野生鲑科幼鱼在淡水洄游中的部分死亡率。
