Identification of circRNA-Associated-ceRNA Networks Involved in Milk Fat Metabolism under Heat Stress
Identification of circRNA-Associated-ceRNA Networks Involved in Milk Fat Metabolism under Heat Stress
复制标题
热应激下参与乳脂代谢的 circRNA 相关 ceRNA 网络的鉴定
DOI：
10.3390/ijms21114162
复制
发表时间：
2020-06-01
影响因子：
5.6
通讯作者：
Sun, Jiajie
中科院分区：
文献类型：
--
作者：
Wang, Dongyang;Chen, Zujing;Sun, Jiajie
中国南部夏季气温普遍较高，奶牛容易出现热应激反应。热应激会对奶牛的生产性能产生负面影响；然而，高温影响哺乳的机制尚不清楚。CircRNA是近年来发现的一种非编码RNA，在许多生物学活动中发挥着重要作用。然而，CircRNA对热应激奶牛哺乳功能的影响尚不清楚。本研究旨在探讨热应激条件下奶牛乳腺组织中CircRNA的表达水平。首先，我们采集了夏、冬两季奶牛的血液和乳样，并用血清指标、产奶量和乳成分来评价泌乳性能。结合温湿度指数的计算，确定了夏季奶牛的热应激状态。热应激使HSP70含量升高，SOD和PRL含量降低。高温胁迫不仅降低了产奶量，而且影响了牛奶的品质，乳糖和乳蛋白随温度升高而降低。对夏季牛奶中脂肪酸组成的分析发现，不饱和脂肪酸的浓度显著降低，特别是长链不饱和脂肪酸。对奶牛乳腺转录组的测序结果表明，与适温(ST)组相比，热应激(HS)组共有2204个上调和3501个下调。GO富集和KEGG通路分析表明，这些基因主要与乳脂代谢相关。此外，还发现了19个上调和19个下调的CircRNA候选基因对热胁迫的反应。我们用皮尔逊检验建立了CircRNA-mRNA之间的相关性，并鉴定了4对CircRNA、6个miRNAs和CD36基因之间的4对CircRNA-miRNA网络。在本研究中，我们揭示了CircRNAs在奶牛哺乳过程中的可能作用，并确定了CircRNA-miRNA-mRNA网络可能存在于奶牛的乳腺中，为奶牛的泌乳和牛奶品质提供了有价值的经验。
Summer temperatures are generally high in Southern China, and cows are likely to suffer a heat stress reaction. Heat stress will have a negative impact on the performance of dairy cows; however, the mechanism by which high temperature affects lactation is not clear. CircRNA is a type of non-coding RNA discovered in recent years, which performs a crucial function in many biological activities. However, the effects of circRNA on lactation function of dairy cows under heat stress is unknown. The present study aimed to explore the expression levels of circRNA in the mammary gland tissue of cows under heat stress. Firstly, we collected blood and milk samples of summer and winter cows and evaluated lactation performance using serum indicators, milk production, and milk composition. Incorporating the calculation of the temperature and humidity index, we conformed the heat stress status of cows in summer. Heat stress increased the concentration of HSP70 and decreased the concentration of SOD and PRL. Heat stress not only reduced milk yield but also affected milk quality, with milk lactose and milk protein decreasing with increased temperature. The analysis of the fatty acid composition in summer milk found significantly reduced concentrations of unsaturated fatty acids, especially long-chain unsaturated fatty acids. Sequencing of the cow’s mammary gland transcriptome revealed that compared to the appropriate temperature (ST) group, the heat stress (HS) group had a total of 2204 upregulated and 3501 downregulated transcripts. GO enrichment and KEGG pathway analysis showed that these genes were mainly related to milk fat metabolism. In addition, 19 upregulated and 19 downregulated circRNA candidates were found in response to heat stress. We used Pearson’s test to establish the correlation of circRNA-mRNA and identified four pairs of circRNA-miRNA networks between four circRNAs, six miRNAs, and the CD36 gene. In this study, we revealed the possible role of circRNAs in lactation of dairy cows and identified that circRNA-miRNA-mRNA networks might exist in the cow’s mammary glands, providing valuable experience for dairy lactation and milk quality.