Filter And Verify Differential Expresseion Of MicroRNAs In The Maternal Placenta Of Cattle With Retained Foetal Membranes

The main purpose of the study was to screen and identify differential expression miRNAs in thematernal placenta of Holstein cattle with retained foetal membranes by the Solexa sequencingand the Bioinformatics analysis method, and searching the key of miRNAs which influence thedevelopment of disease. For Providing a scientific basis of the disease pathogenesis, and toreveal the pathogenesis of disease, to prevent and treat the disease.Three healthy Holstein dairy cows and three Holstein dairy cows with retained foetalmembranes we were chose from an experiment cattle farm at Beian farm, they were similar in age,foetal times, weight and milk yield from an experiment cattle. They were divided into twogroups, NC and RC. Total RNA was extracted from pooled samples with Trizol, and cDNA Libof NC and RC were builted. The two cDNA Lib were sequencing by Solexa. The differentialexepression of miRNA were Screened and indentified. The randomly chosed eight differentialexepression miRNA were verified by Q-Real-time PCR. The differential exepression miRNAwere analyzed by GO and KEGG Pathway.Result: The high reads we obtained was5962381and5446898in the NC and RC libraries,respectively. The length of sRNA mainly was in the scope of19nt-24nt, and22nt was themaximum in the NC and RC cDNA Lib, they were53.76%and56.21%, respectively. The knowsignificantly differential expression of miRNAs were69in the two cDNA Lib, the33miRNAswere up-regulated and36down-regulated compared with NC library(P＜0.05).36and33novelmiRNAs were found respectively in the NC and RC, respectively. The result of Real-time PCRwas similar to deep sequencing. The miRNAs of bta-miR-423-5p, bta-miR-181a andbta-miR-185were significant down-regulated(P＜0.05); bta-miR-411a, bta-miR-31andbta-miR-424-5p were significant up-regulated(P＜0.05); bta-miR-1839and bta-miR-1wereup-regulated but no significant(P＞0.05) to the NC library. The GO results were related to theprotein binding, heterocyclic compound binding, metal ion binding binding and catalytic activity(P＞0.05). The KEGG pathway analysis results were related to the Pathways in cancer,regulation of actin cytoskeleton and MAPK signaling pathway (P＜0.05).There were some differential expression of miRNAs in the maternal placenta of the retained foetal membranes. These miRNAs what form a complex regulatory network may be influence toretained foetal membranes by regulate the expression of genes which especially related to celladhesion and muscle contraction in cattle.