MicroRNAome Of Skeletal Muscle Across Different Developmental Stages In Tibentan Chicken

MicroRNAs(miRNAs)are noncoding,endogenous small RNAs(approximately 22 nucleotides in length)that regulate gene expression by binding to the 3? untranslated region(3 ? UTR)of mRNAs.Increasing evidence has demonstrated that miRNAs exhibit spatiotemporal expression patterns,and that they participate in the regulation of a range of biological processes such as cell proliferation and differentiation,organ development,and tumorigenesis.Muscle mainly composed of muscle fibers,is an important component of animal body.The amount of muscle fiber has a direct effect on meat production.Studies have shown that miRNAs play an important role in muscle growth and development.However,few studies have been carried out on the role of miRNA in different stages of chicken muscle growth and development.The aim of this study was to use high-throughput sequencing technique to sequence two different chicken embryo stages(E5 and E7)and breast muscles of 13 different growth and development stages(E9,E12,E15,E18,E20,D1,D36,D100,D300,Y2,Y5,Y8,Y12).The main results were as follows:(1)By measuring and calculating thecross sectional areasand diameters of muscle fiber in different periods,it was found that the diameters and areas of muscle fiber increased with the development of the chicken skeletal muscle.In comparison between D36 and D1,the diameter and area of muscle fiber of D36 increased significantly,indicating that the volume of muscle fiber was rapidly increasing after hatching in order to maintain the needs of the body.(2)A total of 550,411,352 raw reads were obtained by high-throughput sequencing technique,and 475758014 clean reads were obtained after quality control.(3)A total of 687 known miRNAs were identified,of which 631 were expressed in muscles.A total of 203 new miRNAs were predicted.Furthmore,we found that the number of known miRNAs were decreased along with the development of embryonic,and tended to be stable after birth.(4)About 144,287 and 357 miRNAs were detected significantly differentially expressed between Pre_E and Lat_E,Lat_E and Bir_G,and Pre_E and Bir_G stages byusing DEGseq software.In addition,141 time series differences miRNAs were obtained using time series analysis method,and 6 of them and 3 newly predicted miRNA were verified using q-PCR.(5)Through target gene prediction of differentially expressed miRNAs and enrichment analysis of target genes,most of the pathways are involved in regulating muscle growth and development,such as cell size,steady-state number of cells,negative regulation of neural precursor cells,intracellular protein transport,protein phosphorylation,mTOR,MAPK,WntT,FoxO and insulin signaling pathways.This study was aim to identify the expression profiles of miRNA in chicken muscle at embryonic,adult and aging stages.Our results enrich the information of chicken miRNA and lay a foundation for further understanding the regulation of miRNA on muscle growth and development.At the same time,it also provides a reference for chicken molecular breeding.