Nutrigenomics and Fish Growth Endocrinology Group, Department of Marine Species Biology, Culture and Pathology, Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, Castellón, 12595, Spain.
BMC Genomics. 2012 Sep 11;13:470. doi: 10.1186/1471-2164-13-470.
Studies conducted with gilthead sea bream (Sparus aurata L.) have determined the maximum dietary replacement of fish meal and oil without compromising growth or product quality. The present study aimed to analyze the effect of the nutritional background on fish health and fish fed plant protein-based diets with fish oil (FO diet) or a blend of vegetable oils (66VO diet) were exposed for 102 days to the intestinal myxosporean parasite Enteromyxum leei, and the intestine transcriptome was analyzed with a customized oligo-microarray of 7,500 annotated genes.
Infection prevalence was high and similar in the two diet groups, but the outcome of the disease was more pronounced in fish fed the 66VO diet. No differences were found in the transcriptome of both diet control groups, whereas the number of differentially expressed genes in infected groups was considerable. K-means clustering of these differentially expressed genes identified four expression patterns that reflected the progression of the disease with the magnitude of the fold-change being higher in infected 66VO fish. A positive correlation was found between the time of infection and the magnitude of the transcriptional change within the 66VO group, being higher in early infected animals. Within this diet group, a strong up-regulation of many components of the immune specific response was evidenced, whereas other genes related to complement response and xenobiotic metabolism were down-regulated.
The high replacement of fish oil by vegetable oils in practical fish feeds did not modify the intestine transcriptome of gilthead sea bream, but important changes were apparent when fish were exposed to the myxosporean E. leei. The detected changes were mostly a consequence rather than a cause of the different disease progression in the two diet groups. Hence, the developed microarray constitutes an excellent diagnostic tool to address changes associated with the action of intestinal pathogens, but lacks a prognostic value to predict in advance the different susceptibility of growing fish to the current pathogen.
对金头鲷（Sparus aurata L.）进行的研究确定了在不影响生长或产品质量的情况下，最大程度替代鱼粉和鱼油的饲料。本研究旨在分析营养背景对鱼类健康的影响，并用鱼油（FO 饮食）或混合植物油（66VO 饮食）喂养的植物蛋白基础饮食喂养鱼类 102 天，然后用定制的包含 7500 个注释基因的寡微阵列分析肠道粘孢子虫寄生虫 Enteromyxum leei 的感染情况。
两种饮食组的感染率都很高且相似，但在食用 66VO 饮食的鱼类中，疾病的结果更为明显。两组饮食对照组的转录组没有差异，而感染组差异表达基因的数量相当可观。对这些差异表达基因进行 K-均值聚类，确定了反映疾病进展的四种表达模式，感染的 66VO 鱼类的倍数变化幅度更高。在 66VO 组中，感染时间与转录变化幅度之间存在正相关关系，早期感染动物的变化幅度更高。在该饮食组中，证据表明免疫特异性反应的许多成分强烈上调，而补体反应和外来物质代谢相关的其他基因下调。
在实际鱼类饲料中用植物油大量替代鱼油不会改变金头鲷的肠道转录组，但当鱼类暴露于粘孢子虫 E. leei 时，会出现明显的变化。所检测到的变化主要是两种饮食组中不同疾病进展的结果，而不是原因。因此，所开发的微阵列构成了一种极好的诊断工具，可用于解决与肠道病原体作用相关的变化，但缺乏预测生长鱼类对当前病原体不同易感性的预后价值。
