Selection Of Genes Related To Shedding In Sheep

Wool is an accessory structure produced by the hair follicles in sheep skin,and its growth and shedding are closely related to the skin hair follicles.Tan sheep is a characteristic breed in Ningxia,whose mutton is delicious,but grows slowly.It has long wool and does not fall off by itself.Shcaring in spring is a big problem.The Dorper sheep grows fast,and its wool is short,which can automatically shed in April and May.In this study,ewes of Dorper sheep × Tan sheep athwart cross generations(H1)were selected as the research objects,and the offsprings had two phenotypes of sheddind and unshedding.Therefore,understanding the molecular mechanism of the difference in hair shedding phenotype can provide theoretical support for breeding.In this study,the body skin tissue samples of three shedding sheeps(as group S)and three unshedding sheep(as group U)skin hair follicle development at different stages(anagen-September,catagen-January,telogen-April),and transcriptome sequencing and paraffin section were used to detect the skin,and then used bioinformatics analysis and qRT-PCR verification to deal with the sequencing results,and analyzed the section results.The results were as follows:1.By analyzing the morphological and related trait statistics of skin hair follicle tissues of different groups in different stages,it was found that the diameter of secondary hair follicles was smaller than that of primary hair follicles,and the density of secondary hair follicles(SF)was higher than that of primary hair follicles.The density of SF in S group was lower than that in U group,and that in D group was lower than that in TY group.The depth of hair follicles was the deepest in anagen,and became shallower gradually from catagen to telogen.The depth of hair follicles in group S and group D was shallower than that in group U and TY,respectively.2.Through RNA-seq,a total of 1996 differentially expressed genes(DEGs)were detected in S group,including 1036 up-regulated genes and 602 down-regulated genes,while in U group,there were 309 differential genes,211 up-regulated genes and 98 down-rcgulatcd genes.In U-vs-S group,there were 477 DEGs,growth periods,201 DEGs,regression periods,206 DEGs,resting periods and 70 DEGs.3.By GO function annotation and screening of the differential genes(DEGs)in different periods in and between groups S and U,we found DEGs were related to cell composition and growth and development process,related biological process regulation,body metabolism,binding and catalyst activity.4.KEGG annotation results indicated that DEGs of each group were mainly enriched in disease-related,cytological processes,amino acid synthesis,signal transduction,etc.In addition,14 DEGs(FGF9,FGF23,FGFR1,PDGFD,DTX4,DVL3,Wnt16,COL1A2,COL6A6,Lamb1,IL1RAP,IRF1,IGFBP3,NKD2)were selected in the hair follicle-related pathway MAPK,TGF-?,Notch,PI3K-Akt,Wnt,ECM-receptor interaction,p53,Jak-STAT,TNF,VEGF enrichment.A total of 7 DEGs(PKA,SMAD2,TRAF5,TNXB,IL15,SFRP4,FOSL1)were selected at different periods in the U group and enriched in the Wnt,MAPK,NF-kappa B,ECM-receptor interaction/TGF-? pathway,and we selected the 16 DEGs(TNF,CXCL10,NKD2,CTSW,Pitx2,NFATC2,DLL1,DTX3,MMP3,HSPA8,ITGA11,CYCS,JAK1,IL1RAP,TRAV18,TNXB)between group S and group U,which also enriched in the above hair follicles related pathways.They can be used as the candidate genes which participate in the periodic growth and development of hair follicles and differences in hair shedding phenotypes in groups S and U,it is useful for subsequent gene function studies.4.Using real-time quantitative PCR technology to quantitatively detect gene expression levels of 8 DEGs,the results showed that qRT-PCR results were basically consistent with transcriptome sequencing results.It proved that the transcriptome sequencing and analysis results were true and reliable.