Microarray analysis of differential utilization of plant based diets by rainbow trout

Background: The decreasing availability of fishmeal as a protein source in aquaculture diets will require aquaculture to develop an econmoical and sustainable protien replacement. Plant proteins are readily available and are being tested as a promising alternative to replace a substantial portion of fishmeal which currently provides most of the protein content in aquaculture diets. The types of plant protein feasible for incorporation into aquaculture diets will likely contain various anti-nutritional compounds, carbohydrates, fiber, and a different amino acid profile than what is found in fishmeal. Substantial genetic variation was previously observed for growth on plant based dits in rainbow trout Hence, it will be beneficial to identify metabolic and physiologic pathways related to enhanced plant protein utilization which will aid in identifying genes that contribute to this genetic variation. Results: Microarray analysis of liver samples from two families of rainbow trout that differed in their growth responses when compared between individuals grown on a fish meal or plant protein based diet. Differential expression relating to dietary utilization between the two families found significant changes in expression of 33 ESTs. Eight of the differntially expressed ESTs had identified mammalian homologs that had been previously researched with identified cellular interactions and functions. Conclusions: Utilizing pathway analysis software to analyze sequences annotated with known mammalian genes were were ablet o map gene pathway and process interactions. From this information we were able to infer that the metabolic changes associated with utilization of plant protein versus fishmeal were associated with differential reaulation of genes related to cell oxidative stress, proliferation, growth, and survival. Furthermore, we inferred from the changes we observed in immune response genes expression that ingestion of this plant based diet upregulated the expression of genes involved in immunoregulatroy processes. Overall design: Genotyped samples linked to families that had 4 or more members sampled on each diet were identified and ranked according to average family weight on each diet. Size rankings corresponded to large (>750 g), medium (600-640 g), and small (

背景：随着鱼粉作为水产养殖饲料蛋白质来源的日益减少，水产养殖将需要开发一种经济且可持续的蛋白质替代品。植物蛋白资源丰富，且正在被测试作为鱼粉的潜在替代品，以替代目前在水产养殖饲料中提供大部分蛋白质含量的鱼粉。适用于融入水产养殖饲料的植物蛋白类型可能会含有各种抗营养成分、碳水化合物、纤维，以及与鱼粉不同的氨基酸谱。先前已观察到彩虹鲑在基于植物的饲料中的生长存在显著的遗传变异。因此，识别与植物蛋白利用增强相关的代谢和生理途径将有助于鉴定导致这种遗传变异的基因。结果：对两种不同家族的彩虹鲑的肝脏样本进行微阵列分析，这两种家族在鱼粉或植物蛋白基饲料培养时表现出不同的生长反应。研究发现，两个家族在饮食利用方面的差异表达导致33个ESTs的表达发生显著变化。其中8个差异表达的ESTs已鉴定出哺乳动物同源物，这些同源物之前已被研究，并确定了细胞相互作用和功能。结论：利用通路分析软件分析带有已知哺乳动物基因注释的序列，能够映射基因通路和过程相互作用。据此，我们推断出与植物蛋白利用相比，鱼粉利用相关的代谢变化与细胞氧化应激、增殖、生长和存活相关基因的差异性调节有关。此外，我们根据观察到的免疫反应基因表达变化推断，摄入这种基于植物的饲料上调了参与免疫调节过程的基因表达。总体设计：确定了与具有4个或更多成员的家庭相关联的基因型样本，并根据每个饲料的平均家庭体重进行排名。体型排名对应大型（>750克）、中型（600-640克）和小型（<600克）。