摘要：

剩余采食量(RFI)是用于评价家畜饲料利用效率的重要指标之一,其受消化代谢、肠道免疫、运动及下丘脑采食中枢等多种因素调控。lncRNA是一类参与众多生物学过程的非编码RNA分子,在疾病等表型研究中得到广泛研究,但有关下丘脑lncRNA表达特征及其与牛采食量调控存在何种联系仍不明确。旨在筛选下丘脑中与RFI相关的lncRNA,探究lncRNA与饲料利用率之间的调控关系。选择极端高、低RFI安格斯牛为材料,采集下丘脑组织样本,经总RNA提取、文库构建及高通量测序后开展RFI相关差异表达lncRNA筛选及调控通路分析。共鉴定出105个差异表达lncRNA,其中46个lncRNA在LRFI组下调,59个上调,这些差异lncRNA预测靶基因主要富集于线粒体相关的氧化磷酸化及生热作用等通路;同时上述通路中相关基因(ATP酶、呼吸链复合物)主要与差异表达lncRNA(LNC_006637、LNC_007569、LNC_012079、LNC_005449)相关;蛋白互作网络分析构建的网络中的一些基因(NDUFA4、SDHD、UQCRH)也已被报道为与家畜饲料效率相关。以上结果表明,牛剩余采食量相关的下丘脑组织可能主要通过生热作用及氧化磷酸化信号通路对机体线粒体功能及能量利用进行调节,但这需要更多的细胞试验进行验证。

关键词: 肉牛, 剩余采食量, lncRNA, 下丘脑, 生物信息学

Abstract:

Residual feed intake is one of the most important indicators used to evaluate the efficiency of feed utilization in livestock,which is regulated by various factors such as digestive metabolism,intestinal immunity,locomotion and hypothalamic feeding center.lncRNAs are a class of non-coding RNA molecules involved in numerous biological processes and have been extensively studied in phenotypic studies such as diseases,but it is still unclear about the characteristics of hypothalamic lncRNA expression and how it is linked to the regulation of feed intake in cattle.The aim of this study was to screen for RFI-related lncRNAs in the hypothalamus and to investigate the previous regulatory relationship between lncRNAs and feed utilization.The experiment selected extremely high and low RFI Angus cattle as the material,collected hypothalamic tissue samples,and carried out RFI-related differentially expressed lncRNA screening and regulatory pathway analysis after total RNA extraction,library construction and high-throughput sequencing.105 differentially expressed lncRNAs were identified,of which 46 lncRNAs were down-regulated and 59 were up-regulated in the low RFI group.These differentially expressed lncRNAs were predicted to target genes mainly enriched in mitochondria-related oxidative phosphorylation and thermogenesis pathways;these differential lncRNA predicted target genes were mainly enriched in mitochondria-related oxidative phosphorylation and thermogenesis pathways;meanwhile the related genes(ATPase,respiratory chain complex)in the above pathways were mainly associated with differentially expressed lncRNAs(LNC_006637,LNC_007569,LNC_012079,LNC_005449).Some genes(NDUFA4,SDHD,UQCRH)in the network constructed by protein interaction network analysis had also been reported to be associated with livestock feed efficiency.The above results suggested that the hypothalamic tissue associated with residual feed intake in cattle might regulate mitochondrial function and energy utilization in the body mainly through thermogenesis and oxidative phosphorylation signaling pathways,but more cellular experiments were needed to verify this.

Key words: Beef cattle, Residual feed intake, lncRNA, Hypothalamus, Bioinformatics