Sequencing Analysis Of MiRNA And MRNA In Feather Follicle For Early-feathering And Late-feathering Chickens

Early-feathering and late-feathering in chick are sex-linkage phenotypes which mainly controlled by the alleles K/k.Late-feathering gene K is dominant and early-feathering gene k is recessive.Early-feathering and late-feathering were widely used in the production because they play an important role in many economic traits.In addition,the late-feathering gene K is closely related to the endogenous virus which will increase the incidence of avian leukemia.There are many studies about the production performance and phenotype formation in early-feathering and late-feathering,but the molecular mechanism of the formation of early-feathering and late-feathering is still unclear.In this study,different subtypes of early-feathering and late-feathering were used to analyze the miRN A and mRNA with high-throughput sequencing technology.In addition,the candidate genes of early-feathering and late-feathering were analyzed.The result was showed as follow,(1)The analysis of differentially expressed miRNA,6 up-regulated and 6 down-regulated miRNA were screened in E2-vs-(L2+L4)group,9 up-regulated and 2 down-regulated miRN A were screened in L2-vs-L4 group,20 up-regulated and 11 down-regulated miRNA were screened in E2-vs-L4 group,2 up-regulated and 1 down-regulated were screened in L2-vs-E2 groups.Among them,gga-miR-31-5p was the only miRNA that significantly different expressed in these groups,it was suggested to be associated with feather follicles and feather development.This target genes of these differentially expressed miRNAs manily involved in the positive regulation of epithelial cell migration,protein dimerization activity,fibroblast growth factor receptor binding and Protein digestion and absorption etc.(2)The analysis of differentially expressed mRNA.314 up-regulated and 875 down-regulated mRNA were screened in E2-vs-(L2+L4)group,1211 up-regulated and 1682 down-regulated mRNA were screened in E2-vs-L4 group,870 up-regulated and 932 down-regulated were screened in L2-vs-L4 group,172 up-regulated and 29 down-regulated mRNA were screened in L2-vs-E2 group.These differentially expressed mRNAs manily involved in the growth factor activity,epithelial cell differentiation,calcium ion binding,Protein digestion and absorption and Vascular smooth muscle contraction etc.Among them,EGF was significantly down-regulated in early-feathering than that in late-feathering,suggesting that it was associated with the feather development in chicken.(3)The analysis of the pathway about hair follicle and feather development,there were 6 and 16 miRN A targeted the genes in WNT/?-catenin,SHH/BMP2 and Notch signaling pathways about feathering development,4 and 7 miRN A-mRNA pairs were screened in L2-vs-L4 and E2-vs-L4 groups respectively.A pair(gga-miR-6651-5p-LRP4)was unique to L2-vs-L4 group,4 pair(gga-miR-2954-WNT3 A,gga-miR-34a-5p-TCF7,gga-miR-130a-5p-CRB2,gga-miR-1663-5p-CTBP2)were unique to E2-vs-L4 group,Further study needs to be explore whether they were related to feathering development.(4)The analysis of candidate genes for early-feathering and late-feathering.Late-feathering(L4+L2)as control,only SPEF2 was significantly down-regulated in early-feathering;In the subtype comparison,PRLR was significantly down-regulated only in the E2-vs-L4 group,SPEF2 was significantly downregulated and upregulated in the E2-vs-L4 and L2-vs-E2 groups respectively,but there was no significant difference in L2-vs-E2 group,PRLR and SPEF2 were speculated to be related to the development of hair follicle and feathering,SPEF2 was more suitable as candidate genes for rearly-feathering and late-feathering,but not proposed candidate genes for feathering subtypes of chicks.