Effect of dietary restriction and subsequent re-alimentation on the transcriptional profile of hepatic tissue in cattle.
Effect of dietary restriction and subsequent re-alimentation on the transcriptional profile of hepatic tissue in cattle.
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DOI：
10.1186/s12864-016-2578-5
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发表时间：
2016-03-17
期刊：
影响因子：
4.4
通讯作者：
Waters SM
中科院分区：
文献类型：
--
作者：
Keogh K;Kenny DA;Cormican P;Kelly AK;Waters SM
补偿性生长（CG）是动物在一段时间的饮食限制后重新补充营养时观察到的加速生长现象。它通常用于牲畜系统，以在饲料供应减少期间降低饲料成本。然而，控制这种现象的生化机制尚未阐明。本研究旨在利用RNAseq揭示调节牛中CG肝脏表达的分子机制。在125天的饮食限制（RES）后以及在55天的后续再营养后再次对公牛的肝组织进行RNAseq，在此期间动物表现出显著的CG。将数据与在整个过程中随意提供相同饮食的对照动物（ADLIB）的数据进行比较。阐明CG的分子控制可能产生关于基因和途径的关键信息，这些基因和途径可以作为推定的分子生物标志物，用于选择具有改善CG潜力的动物。经过一段时间的差异喂养，体重和肝脏重量分别为161和4公斤，分别为ADLIB与RES动物相比。此时，肝组织的RNAseq分析揭示了两种治疗之间的1352个显著差异表达的基因（DEG）。DEG表明，包括营养物质的运输，细胞分裂和增殖的过程中，在RES下调。此外，蛋白质合成基因上调RES后，一段时间的限制喂养。随后55天，两组动物自由采食，导致体重差异降至84 kg，治疗组间肝脏重量无差异。在55天的无限制喂养结束时，49个基因差异表达的动物进行CG和他们的连续喂养的同行。特别是，在接受CG的动物中，细胞增殖和生长基因的肝脏表达更高。CG期间细胞周期和细胞增殖基因的更大表达与再营养期间肝脏重量的100%恢复相关。此外，在限制喂养过程中细胞蛋白质合成能力的明显上调可能有助于并维持再营养过程中的CG。DEG的鉴定是潜在的候选基因，用于确定CG的生物标志物，这可能会被纳入未来的育种计划。本文的在线版本（doi：10.1186/s12864-016-2578-5）包含补充材料，可供授权用户使用。
Compensatory growth (CG) is an accelerated growth phenomenon observed in animals upon re-alimentation following a period of dietary restriction. It is typically utilised in livestock systems to reduce feed costs during periods of reduced feed availability. The biochemical mechanisms controlling this phenomenon, however, are yet to be elucidated. This study aimed to uncover the molecular mechanisms regulating the hepatic expression of CG in cattle, utilising RNAseq. RNAseq was performed on hepatic tissue of bulls following 125 days of dietary restriction (RES) and again following 55 days of subsequent re-alimentation during which the animals exhibited significant CG. The data were compared with those of control animals offered the same diet on an ad libitum basis throughout (ADLIB). Elucidation of the molecular control of CG may yield critical information on genes and pathways which could be targeted as putative molecular biomarkers for the selection of animals with improved CG potential. Following a period of differential feeding, body-weight and liver weight were 161 and 4 kg higher, respectively, for ADLIB compared with RES animals. At this time RNAseq analysis of liver tissue revealed 1352 significantly differentially expressed genes (DEG) between the two treatments. DEGs indicated down-regulation of processes including nutrient transport, cell division and proliferation in RES. In addition, protein synthesis genes were up-regulated in RES following a period of restricted feeding. The subsequent 55 days of ad libitum feeding for both groups resulted in the body-weight difference reduced to 84 kg, with no difference in liver weight between treatment groups. At the end of 55 days of unrestricted feeding, 49 genes were differentially expressed between animals undergoing CG and their continuously fed counterparts. In particular, hepatic expression of cell proliferation and growth genes were greater in animals undergoing CG. Greater expression of cell cycle and cell proliferation genes during CG was associated with a 100 % recovery of liver weight during re-alimentation. Additionally, an apparent up-regulation in capacity for cellular protein synthesis during restricted feeding may contribute to and sustain CG during re-alimentation. DEGs identified are potential candidate genes for the identification of biomarkers for CG, which may be incorporated into future breeding programmes. The online version of this article (doi:10.1186/s12864-016-2578-5) contains supplementary material, which is available to authorized users.