Identification And Function Prediction Of LncRNA In Muscle Tissues Of Sunid Sheep At Different Stages

In this study,RNA-Seq technology was used to compare and analyze 120-day skeletal muscle of Sunid sheep fetus and 5-month-old lamb muscle tissue,screen out differentially expressed lncRNA and its target genes,and perform GO and KEGG on predicted mRNA At the same time,qRT-PCR was used to verify the randomly selected differentially expressed lncRNA.The study of lncRNA related to skeletal muscle of Sunid sheep provides an important theoretical basis for further understanding the genetic regulation mechanism of muscle growth and development,and also provides a new way for molecular assisted breeding of sheep.The main findings are as follows:（1）The length,exon number,exon size and expression level of lncRNA and mRNA were compared and analyzed.Compared with mRNA,it was found that the number of lncRNAs with lncRNA length range of 200bp-3000bp accounted for 80.0%of the total lncRNA.The number of lncRNAs containing two and three exons accounted for 87.3%（971）of all lncRNAs.The ORF length of mRNA is significantly larger than lncRNA.By comparing the expression levels of lncRNA and mRNA obtained by sequencing,it was found that the overall expression level of mRNA was significantly higher than that of lncRNA.（2）A total of 1112 lncRNAs were found,including 586 known lncRNAs and 526 new lncRNAs.Among them,the number of differentially expressed lncRNAs at different developmental stages was 626,and a total of 1273 mRNA encoding genes were targeted.（3）By comparing the FPKM values of lncRNA in different samples,it was found that the expression levels of ENSOART00000028118 and LNC 000424 in the 5-month-old lamb group were significantly up-regulated,and ENSOART00000028118 and LNC₀00424 were down-regulated in the development of fetal 120-day-old muscle tissue,and in the 5-month-old lamb muscle upregulated during tissue development.The expression levels of ENSOART00000028271,LNC₀00311 and LNC₀00719 in 5 months old lamb muscle tissue were significantly down-regulated.It indicates that the expression regulation of lncRNA has different expression directions in different periods,but still needs further experimental verification.（4）In this study,13 lncRNAs with higher expression levels,ENSOART00000028118,ENSOART00000028384,ENSOART00000027214,ENSOART00000028894,LNC₀00196,LNC₀00231,LNC₀00269,LNC₀00307,LNC₀00311,LNC₀00421,LNC₀00422,LNC₀0459,and LNC1 EPS8L1,RTL1,SIRT1,TRIM7,KLHL40,TNNI1,MEF2C,FOSB,JPH2 and MYH1.（5）GO and KEGG analysis showed that these differential genes are mainly involved in the regulation of metabolic processes,biosynthesis,gene expression,protein binding,and Wnt signaling pathway.Notch signaling pathway,Gap connection,and thyroid hormone synthesis and other signaling pathways.（6）The qRT-PCR test results showed that the expression levels of 8 randomly selected lncRNAs in muscle tissue were consistent with the RNA-seq results,which proved that the sequencing results had high accuracy.