Comparative Analysis Of MicroRNA In Yak, Ordinary Cattle And Catttle-yak Testis Tissue

The offspring of yak with cow hybridization,cattle-yak has significant heterosis.For example,amount of meat and milk were higher than that of yak. But the male cattle-yak is of the sterility, utilization of heterosis is limited greatly.In order to understand the function of miRNA in cattle-yak testicular and reproductive control in the process of, illustrate the genetic regulation of reproductive endocrine mechanism, the study researched identificated miRNAs of yak, ordinary cattle and cattle-yak testicular tissue as well as realated miRNAs biological function.The results showed that:(1) There are 73183534, 75781455 and 73183534 high quality sequence from yaks, ordinary cattle and cattle-yak testicular tissue through small RNA high-throughput sequencing.After controlling the quality, the clean data of yaks, ordinary cattle and cattle-yak are respectively 71008752, 72004961 and 71008752, and corresponding unique sequence 8544379, 9793585, 8859608.Most sequence length of cattle-yak distributs in the 20 to 23 nt. The 22 nt length sequence is typical of microRNAs sequence length and the largest proportion of shows. The cattle-yak testicular tissue are rich in micro RNAs. Ordinary cattle and yak sRNA sequence length distribution characteristic is bimodal, and peak appeared respectively in 21 ~ 23 nt and 26 ~ 30 nt.(2) The known microRNAs precursor has 509,511 and 511 in yaks, ordinary cattle and cattle-yak,and the corresponding known mature microRNAs were 473,478 and 478 respectively.From the top 30 of microRNAs expression in the libraries(all account for more than 80% of all the miRNA always express quantity),we found bta-miR-10 b is expression quantity highest among three libraries.The top 15 high expression quantity in three libraries are 19 microRNAs in total, bta-miR-10 b, bta-miR-143, bta-let-7a-5p, bta-miR-26, bta-miR-146 b, bta-miR-125 b, bta-miR-100, bta-miR-148 a,bta-miR-125 a,bta-miR-99a-5p,bta-let-7f,bta-miR-191,bta-let-7g,bta-mi R-22-3p,bta-let-7b,bta-miR-34 c,bta-miR-6526, bta-miR-27 b, bta-miR-151-5p.(3) A total of 439 microRNAs were identified in both three libraries. Ordinary cattle, yaks and cattle-yak testis specific expression microRNAs respectively are 10, 9 and 69.Compared with catttle, cattle-yak has 8 lower expression and 321 higher expression microRNA.Compared with yak library,11 were downregulated and 312 were upregulated in significantly in cattle-yak library. Downregulate microRNAs of cattle-yak testis has 11 that bta-mi R-34 b, bta-miR-2384, miR-449 a and bta-miR-34 c, bta-miR-449 b, bta-miR-449 c, bta-mi R-375, bta-miR-133 b, bta-mi R-190, bta-miR-7 b, bta-miR-208, bta-miR-6526.The top 15 among three libraries besides bta-miR-34 c, bta-miR-6526 upregulated in cattle-yak library.(4) The main target of miRNA target genes involved in biological process regulation, gene expression regulation, cell apoptosis, cell differentiation, such as biological processes, with protein function, participate in the activities of signal transduction.Bta-miR-10 b and bta-miR-34 c target genes involved in nucleotide expression after combination, gene transcription regulation, purine nucleoside combined with biological processes, etc.Target genes mainly in Wnt signaling pathways, Toll receptor signaling pathways, gonadotropin-releasing hormone receptor pathway, TGF-beta angiogenesis, apoptosis, signal transduction pathway, p53 pathway in cell signaling pathways in reproductive related, such as enrichment significantly.A high percentage of testis express the mi RNA regulation target genes related to cell apoptosis mechanism, may be associated with cattle-yak sperm in block.