The effect of reduced feed ration on infestation levels with the sea louse Lepeophtheirus salmonis and gene expression in juvenile pink salmon Oncorhynchus gorbuscha was tested in three laboratory trials. Body weight was significantly lower among fish on the reduced ration for 27, 34, or 65 d than fish on the full ration. Neither the prevalence nor the abundance of L. salmonis differed between fish on full and reduced rations at any time in any trial. In trial 2, sea louse rejection was delayed among fish on reduced rations; however, the parasite was ultimately rejected from all fish in this trial regardless of ration. Proinflammatory gene expression in salmon exposed to L. salmonis was modulated by reduced rations. There was a reduction in the expression of interleukin-8 in pink salmon on reduced rations 7 d after exposure but not 14 d after exposure. In contrast, the 7-d expression of interleukin-1 beta (IL-1beta) was reduced in exposed pink salmon regardless of ration. By day 14, however, expression of IL-1beta was increased in association with reduced rations among exposed salmon. Similarly, the expression of tumor necrosis factor alpha (TNFalpha) was increased 14 d after exposure among salmon on a reduced ration. There was no evidence that short-duration exposure of otherwise healthy juvenile pink salmon to a reduced ration affected susceptibility to L. salmonis. The expression data do not suggest an obvious mechanism of louse rejection; rather, they indicate that a more comprehensive suite of inflammatory pathways should be surveyed to better understand the early pink salmon response to L. salmonis.

中文翻译：

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减少饲料日粮对粉红鲑鱼幼鱼侵染和炎症基因表达的影响

在三个实验室试验中测试了减少饲料配给对海虱 Lepeophtheirus 鲑鱼的侵染水平和幼年粉红鲑鱼 Oncorhynchus gorbuscha 基因表达的影响。在 27、34 或 65 天，减少日粮的鱼的体重明显低于全日粮的鱼。在任何试验中的任何时间，全口粮和减少口粮的鱼的鲑鱼的流行率和丰度都没有差异。在试验 2 中，减少口粮的鱼延迟了海虱排斥反应；然而，无论定量如何，该试验中的所有鱼类最终都拒绝了这种寄生虫。暴露于 L.salmonis 的鲑鱼的促炎基因表达受到减少的口粮的调节。在暴露后 7 天，但在暴露后 14 天，减少日粮的粉红鲑鱼中白细胞介素 8 的表达降低。相比之下，无论日粮如何，暴露的粉红鲑鱼中白细胞介素 1 β (IL-1beta) 的 7 天表达量减少。然而，到第 14 天，IL-1beta 的表达增加，与暴露的鲑鱼之间的口粮减少有关。类似地，在减少日粮的鲑鱼中，肿瘤坏死因子α（TNFα）的表达在暴露后 14 天增加。没有证据表明健康的粉红鲑鱼幼鱼短期暴露于减少的日粮中会影响对鲑鱼的易感性。表达数据没有表明虱子排斥的明显机制；相当，