title: Deep Sequencing and Screening of Differentially Expressed MicroRNAs Related to Milk Fat Metabolism in Bovine Primary Mammary Epithelial Cells.
abstract: Milk fat is a key factor affecting milk quality and is also a major trait targeted in dairy cow breeding. To determine how the synthesis and the metabolism of lipids in bovine milk is regulated at the miRNA level, primary mammary epithelial cells (pMEC) derived from two Chinese Holstein dairy cows that produced extreme differences in milk fat percentage were cultured by the method of tissue nubbles culture. Small RNA libraries were constructed from each of the two pMEC groups, and Solexa sequencing and bioinformatics analysis were then used to determine the abundance of miRNAs and their differential expression pattern between pMECs. Target genes and functional prediction of differentially expressed miRNAs by Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes analysis illustrated their roles in milk fat metabolism. Results show that a total of 292 known miRNAs and 116 novel miRNAs were detected in both pMECs. Identification of known and novel miRNA candidates demonstrated the feasibility and sensitivity of sequencing at the cellular level. Additionally, 97 miRNAs were significantly differentially expressed between the pMECs. Finally, three miRNAs including bta-miR-33a, bta-miR-152 and bta-miR-224 whose predicted target genes were annotated to the pathway of lipid metabolism were screened and verified by real-time qPCR and Western-blotting experiments. This study is the first comparative profiling of the miRNA transcriptome in pMECs that produce different milk fat content.
authors.affiliation: College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun 130062, China. binglei514@163.com.|College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China. binglei514@163.com.
authors.forename: Binglei
authors.initials: B
authors.lastname: Shen
authors.affiliation: College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun 130062, China. lyzhang@jlu.edu.cn.
authors.forename: Liying
authors.initials: L
authors.lastname: Zhang
authors.affiliation: National Key Laboratory of Veterinary Biotechnology and Laboratory Animal and Comparative Medicine Unit, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China. lianchuanjiang@caas.cn.
authors.forename: Chuanjiang
authors.initials: C
authors.lastname: Lian
authors.affiliation: College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun 130062, China. cylu@jlu.edu.cn.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Lu
authors.affiliation: College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun 130062, China. yyzhang@jlu.edu.cn.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China. 18004598498@163.com.
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Pan
authors.affiliation: College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun 130062, China. yrj@jlu.edu.cn.
authors.forename: Runjun
authors.initials: R
authors.lastname: Yang
authors.affiliation: College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun 130062, China. zhzhao@jlu.edu.cn.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Zhao
mesh_terms: D000818:Animals; D002417:Cattle; D019295:Computational Biology / Q000379:methods; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D005786:Gene Expression Regulation; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D050356:Lipid Metabolism; D008321:Mammary Glands, Animal / Q000166:cytology / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics*; D008892:Milk / Q000737:chemistry* / Q000592:standards
chemical_list: D035683:MicroRNAs
keywords: Solexa sequencing; dairy cow; microRNA; milk fat; primary mammary epithelial cell