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草业学报 ›› 2023, Vol. 32 ›› Issue (10): 173-186.DOI: 10.11686/cyxb2022449

• 研究论文 • 上一篇    

苜蓿源miR168b跨界调控奶牛体内乳脂相关靶基因的筛选

贾晶莹1,2(), 刘宝宝1,2, 马云1,2, 段红娟1,2, 蔡小艳1,2()   

  1. 1.宁夏大学农学院,宁夏 银川 750021
    2.宁夏回族自治区反刍动物分子细胞育种重点实验室,宁夏 银川 750021
  • 收稿日期:2022-11-14 修回日期:2023-02-21 出版日期:2023-10-20 发布日期:2023-07-26
  • 通讯作者: 蔡小艳
  • 作者简介:E-mail: caixiaoyan282@163.com
    贾晶莹(1998-),女,河北衡水人,在读硕士。E-mail: jiajingying176@163.com
  • 基金资助:
    国家自然基金项目(31960680);宁夏科技厅优秀青年项目(2022AAC05012);宁夏重点研发引才专项(2018BEB04031);宁夏大学引进人才科研启动费(030900002218);宁夏自然科学基金重点项目(2023AAC02012)

Screening of target genes related to milk fat in dairy cows regulated by alfalfa miR168b

Jing-ying JIA1,2(), Bao-bao LIU1,2, Yun MA1,2, Hong-juan DUAN1,2, Xiao-yan CAI1,2()   

  1. 1.School of Agricultural,Ningxia University,Yinchuan 750021,China
    2.Key Laboratory of Ruminant Molecular Cell Breeding,Ningxia Hui Autonomous Region,Yinchuan 750021,China
  • Received:2022-11-14 Revised:2023-02-21 Online:2023-10-20 Published:2023-07-26
  • Contact: Xiao-yan CAI

摘要:

筛选出高乳脂奶牛和低乳脂奶牛血液和牛奶中显著差异表达的苜蓿来源miRNAs及其在奶牛体内的潜在靶基因,可为进一步探究苜蓿源miRNAs(mtr-miRNAs)在基因水平调节牛奶乳脂率奠定基础。试验首先对生产4胎,日粮水平一致的荷斯坦奶牛牛奶进行了奶牛生产性能(dairy herd improvement, DHI)检测,在高乳脂和低乳脂奶牛中各选3头作为重复。运用RT-qPCR对奶牛血液和牛奶中的苜蓿源miRNAs进行定量,筛选出差异表达miRNAs后对其进行靶基因预测和分析,并根据miRNA-mRNA结合位点和定量结果筛选出与乳脂代谢相关的靶基因。结果如下:1)DHI检测筛选出了3头高乳脂奶牛和3头低乳脂奶牛,高乳脂奶牛牛奶中脂肪含量>4.2%,低乳脂奶牛牛奶中脂肪含量<3.5%;2)苜蓿源novel-miR54、miR156f、miR166a、miR168b和miR168c-3p在奶牛血液和牛奶中均能检测到,其中mtr-miR168b在高乳脂奶牛血液中的表达量极显著低于在低乳脂奶牛中的表达量(P<0.01),在高乳脂奶牛牛奶中的表达量显著低于在低乳脂奶牛中的表达量(P<0.05);3)mtr-miR168b在乳腺上皮细胞中高表达抑制了其中脂代谢标志基因PPARγSCD1CEBP/βSREBP1的表达量;4)mtr-miR168b预测靶基因分别有1834和296个与GO和KEGG数据库比对成功,靶基因主要与N-聚糖生物合成(3.72%)、cGMP-PKG信号通路(2.37%)和血管平滑肌收缩(2.37%)密切相关,甘油磷脂代谢(1.69%)通路也被显著富集;5)筛选出CPT1ASTARD7两个与脂代谢密切相关的基因,并通过双荧光素酶报告确认了miR-168b和CPT1A与STARD7的靶向关系。由此可见,mtr-miR168b可抑制乳腺上皮细胞中的成脂标志基因的表达,试验为后续验证苜蓿源miRNAs调控奶牛乳脂率提供了可进一步验证的靶基因。

关键词: 荷斯坦奶牛, 跨界调控, mtr-miR168b, 乳脂, 靶基因

Abstract:

The alfalfa (Medicago sativa) miRNAs expressed significantly differently in the blood and milk of high-fat dairy cows and low-fat dairy cows and their potential target genes in dairy cows were screened out in order to lay a foundation for further exploring the regulation of milk fat level by alfalfa miRNAs at gene level. Firstly, the level of dairy herd improvement (DHI) was measured in milk of Holstein cows which had produced 4 fetuses and had the same dietary level. Three cows were selected from high-and low-milk-fat cows as duplicates and RT-qPCR was used to quantify alfalfa miRNAs in milk and blood of the dairy cows. After screening out differentially expressed miRNAs, the target genes were predicted and analyzed, and the target genes related to milk fat metabolism were screened according to the binding sites and quantitative results by miRNA-mRNA. The results were as follows: 1) Three high-fat dairy cows and three low-fat dairy cows were identified by their DHI score. The fat content in the milk of high-fat dairy cows was >4.2%, and that of low-fat dairy cows was <3.5%. 2) Alfalfa sourced novel-miR54, miR156f, miR166a, miR168b and miR168c-3p were detected in cow blood and milk. The expression level of miR168b in the blood of high-fat milk cows was extremely significantly lower than that in low-fat milk cows (P<0.01), and similarly the expression level of miR168b in the milk of high-fat milk cows was significantly lower than that in low-fat milk cows (P<0.05). 3) The high expression of mtr-miR168b in mammary epithelial cells inhibited the expression of adipogenic marker genes PPARγSCD1CEBP/β and SREBP1. 4) GO and KEGG databases indicated 1834 and 296 target genes, respectively, predicted by mtr-miR168b. The predicted target genes were closely related to N-glycan biosynthesis (3.72%), the cGMP-PKG signaling pathway (2.37%) and vascular smooth muscle contraction (2.37%) and the glycerophosphate metabolism pathway (1.69%) was also significantly enriched. 5) CPT1A and STARD7, two genes closely related to lipid metabolism, were also screened. A targeting relationship between miR-168b and CPT1A was confirmed by dual-luciferase report. In conclusion, mtr-miR168b can regulate milk fat production by inhibiting the expression of adipogenic marker genes in mammary epithelial cells, and this study identifies target genes for further verification of alfalfa miRNA regulation of milk fat percentage in dairy cows.

Key words: Holstein cow, cross-kingdom regulation, mtr-miR168b, milk fat, target gene