Liu LingLing, Fang Chao, Sun YinZe, Liu WuJun
College of Animal Science, Xinjiang Agriculture University, Urumqi, Xinjiang, China.
Department of Animal Production, Farah Research Centre from the Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.
PeerJ. 2021 Feb 23;9:e10796. doi: 10.7717/peerj.10796. eCollection 2021.
miRNA has an important role in cell differentiation, biological development, and physiology. Milk production is an important quantitative trait in livestock and miRNA plays a role in the amount of milk produced.
The role of regulatory miRNAs involved in equine milk production is not fully understood. We constructed two miRNA libraries for Kazakh horse milk production from higher-producing (H group) and lower-producing (L group) individuals, and used RNA-Seq technology to identify the differentially expressed miRNAs between the two milk phenotypes of Kazakh horses.
A total of 341 known and 333 novel miRNAs were detected from the H and L groups, respectively. Eighty-three differentially expressed miRNAs were identified between the H and L group s, of which 32 were known miRNAs (27 were up-regulated, five were down-regulated) and 51 were novel miRNAs (nine were up-regulated, 42 were down-regulated). A total of 2,415 genes were identified. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that these genes were annotated to mammary gland development, mammary gland morphogenesis, tissue development and PI3K-Akt signaling pathways, insulin signaling pathway and TGF-beta signaling pathway, among others. Five miRNAs (miR-199a-3p, miR143, miR145, miR221, miR486-5p) were identified as affecting horse milk production and these five miRNAs were validated using qRT-PCR.
We described a methodology for the transcriptome-wide profiling of miRNAs in milk, which may help the design of new intervention strategies to improve the milk yield of Kazakh horses.
微小RNA（miRNA）在细胞分化、生物发育和生理学中发挥着重要作用。产奶量是家畜的一个重要数量性状，miRNA在产奶量方面发挥作用。
参与马奶生产的调控性miRNA的作用尚未完全了解。我们构建了两个哈萨克马产奶的miRNA文库，分别来自高产（H组）和低产（L组）个体，并使用RNA测序技术鉴定哈萨克马两种产奶表型之间差异表达的miRNA。
分别从H组和L组中检测到341个已知miRNA和333个新miRNA。在H组和L组之间鉴定出83个差异表达的miRNA，其中32个是已知miRNA（27个上调，5个下调），51个是新miRNA（9个上调，42个下调）。共鉴定出2415个基因。基因本体论（GO）和京都基因与基因组百科全书（KEGG）通路分析表明，这些基因被注释到乳腺发育、乳腺形态发生、组织发育以及PI3K-Akt信号通路、胰岛素信号通路和TGF-β信号通路等。鉴定出5个miRNA（miR-199a-3p、miR143、miR145、miR221、miR486-5p）影响马奶产量，并使用qRT-PCR对这5个miRNA进行了验证。
我们描述了一种对牛奶中miRNA进行全转录组分析的方法，这可能有助于设计新的干预策略以提高哈萨克马的产奶量。
