Gondret Florence, Vincent Annie, Houée-Bigot Magalie, Siegel Anne, Lagarrigue Sandrine, Causeur David, Gilbert Hélène, Louveau Isabelle
Pegase, Agrocampus Ouest, INRA, 35590, Saint-Gilles, France.
Laboratoire de Mathématiques Appliquées, IRMAR, Agrocampus Ouest, 35000, Rennes, France.
BMC Genomics. 2017 Mar 21;18(1):244. doi: 10.1186/s12864-017-3639-0.
Animal's efficiency in converting feed into lean gain is a critical issue for the profitability of meat industries. This study aimed to describe shared and specific molecular responses in different tissues of pigs divergently selected over eight generations for residual feed intake (RFI).
Pigs from the low RFI line had an improved gain-to-feed ratio during the test period and displayed higher leanness but similar adiposity when compared with pigs from the high RFI line at 132 days of age. Transcriptomics data were generated from longissimus muscle, liver and two adipose tissues using a porcine microarray and analyzed for the line effect (n = 24 pigs per line). The most apparent effect of the line was seen in muscle, whereas subcutaneous adipose tissue was the less affected tissue. Molecular data were analyzed by bioinformatics and subjected to multidimensional statistics to identify common biological processes across tissues and key genes participating to differences in the genetics of feed efficiency. Immune response, response to oxidative stress and protein metabolism were the main biological pathways shared by the four tissues that distinguished pigs from the low or high RFI lines. Many immune genes were under-expressed in the four tissues of the most efficient pigs. The main genes contributing to difference between pigs from the low vs high RFI lines were CD40, CTSC and NTN1. Different genes associated with energy use were modulated in a tissue-specific manner between the two lines. The gene expression program related to glycogen utilization was specifically up-regulated in muscle of pigs from the low RFI line (more efficient). Genes involved in fatty acid oxidation were down-regulated in muscle but were promoted in adipose tissues of the same pigs when compared with pigs from the high RFI line (less efficient). This underlined opposite line-associated strategies for energy use in skeletal muscle and adipose tissue. Genes related to cholesterol synthesis and efflux in liver and perirenal fat were also differentially regulated in pigs from the low vs high RFI lines.
Non-productive functions such as immunity, defense against pathogens and oxidative stress contribute likely to inter-individual variations in feed efficiency.
动物将饲料转化为瘦肉增重的效率是肉类行业盈利能力的关键问题。本研究旨在描述在八代中针对剩余采食量（RFI）进行不同选择的猪的不同组织中共享的和特定的分子反应。
在132日龄时，与高RFI品系的猪相比，低RFI品系的猪在试验期内的料重比有所改善，瘦肉率更高，但脂肪含量相似。使用猪微阵列从背最长肌、肝脏和两个脂肪组织中生成转录组学数据，并分析品系效应（每个品系n = 24头猪）。品系的最明显效应在肌肉中可见，而皮下脂肪组织是受影响较小的组织。通过生物信息学分析分子数据，并进行多维统计，以识别不同组织间共同的生物学过程以及参与饲料效率遗传差异的关键基因。免疫反应、对氧化应激的反应和蛋白质代谢是区分低RFI或高RFI品系猪的四个组织共有的主要生物学途径。许多免疫基因在效率最高的猪的四个组织中表达下调。导致低RFI和高RFI品系猪之间差异的主要基因是CD40、CTSC和NTN1。两个品系之间，与能量利用相关的不同基因以组织特异性方式受到调节。与糖原利用相关的基因表达程序在低RFI品系（效率更高）猪的肌肉中特异性上调。与高RFI品系（效率较低）猪相比，参与脂肪酸氧化的基因在肌肉中下调，但在同一猪的脂肪组织中上调。这突出了骨骼肌和脂肪组织中与品系相关的相反能量利用策略。肝脏和肾周脂肪中与胆固醇合成和流出相关的基因在低RFI和高RFI品系猪中也受到不同调节。
免疫、抵抗病原体和氧化应激等非生产性功能可能导致个体间饲料效率的差异。
