Screen The Differentially Expressed Genes Of Skin Tissue In Fine-wool Sheep And Analysis Of Genetic Effects

The study based on the results of SNP-GWAS and CNV-GWAS for important wool traits in fine-wool sheep using markers of different densities,screened 12 candidate genes to analyze the differential expression of mRNA in different fiber diameter on fine-wool sheep skin tissues,and combined with the results of tissue expression profile and DNA pools with the re-sequencing.Furthermore,10 SNPs of LAMB1 gene and 2 SNPs of FZD3 gene were analyzed for their association with the economic traits of fine-wool sheep.The main results of this study are as follows:(1)Differential expression analysis of candidate genes in economic traits of fine-wool sheep: Twelve genes were screened and the relative expression of mRNA was detected by RT-PCR in superfine and fine-wool sheep tissues.The results showed that there were nine differentially expressed genes: FZD3,ARPP21,LMNB1,RASA1,PAK1,IFNAR2,FAT3,CD1 A and Notch2.There were three non-differentially expressed genes: TFG,IFT57 and WNT4.Taking the fine group as the control,the up-regulated genes in the superfine-wool sheep are ARPP21,LMNB1,IFNAR2,CD1 A and Notch2;while the down-regulated genes are FZD3,RASA1,PAK1,FAT3.The mRNA expression of PAK1 gene in fine-wool sheep skin tissue was significantly higher than that of superfine-wool sheep.The expression of ARPP21,IFNAR2 and CD1 A genes mRNA in superfine-wool sheep skin tissue was significantly higher than that in fine-wool sheep.GO biological enrichment results show that,participating in biological processes,cell processes,WNT signaling pathways,hair cycle,regulatory molecular functions and other biological processes of multiple differentially expressed genes may vary by affecting the wool differentiation process and skin hair follicle development to change the fiber diameter.The discovery of these genes will provide a theoretical basis for further screening of molecular markers of wool traits with potential application value.(2)Analysis of LAMB1 gene SNPs in fine-wool sheep: Laminin-beta-1(LAMB1)gene is the member of the laminin family,and plays an important role in biological processes.To analyze the genetic effects associated with the wool traits of candidate genes LAMB1,based on DNA pools with the re-sequencing technology to screened 10 SNPs data of LAMB1 gene exon regions,combining with PCR-SSCP technology to type the genotype,the genetic effects of LAMB1 gene 10 SNPs on wool traits of totally 418 fine-wool sheep at Xinjiang Kunes farm were analyzed by the GLM of SAS 8.1.Linkage disequilibrium(LD)was used by HaploView 4.2.The results showed this population genetic variations of fine-wool sheep was in the medium level,there were 7 non-synonymous mutation SNPs.AA and GA genotype in the identification of the body weight and body weight after shearingk of the individual value was extremely significant higher than GG genotype on SNP2(P<0.01).CC,TT and TC genotypes in the staple length of the individual value was extremely significant on SNP4(P<0.01).CC genotype in the body weight after shearingk of the individual value was extremely significant higher than TT and TC genotype on SNP4(P<0.01).While,eachgenotypes in the part of wool traits on other SNPs were significance(P<0.05).SNP1 and SNP3,SNP2 and SNP3 were in the linkage disequilibrium state,LAMB1 gene might be used as one of a potential and valuable candidate molecular marker on wool traits in fine-wool sheep.The study revealed the molecular genetic features of LAMB1 gene and evaluate the genetic relationship in fine-wool sheep.The results provide molecular genetic basis for efficient breeding of fine-wool sheep breeds,and efficient conservation and utilization the germplasm resources.(3)Analysis of FZD3 gene SNPs in fine-wool sheep: Based on DNA pools with the re-sequencing,two SNPs of FZD3 gene which could be significantly related to wool traits were screened,FZD3 gene exon1 region G101762204A(SNP1)and exon 3 region T101800405C(SNP2)were detected polymorphism by PCR-SSCP technology and analyzed the genetic effect analysis.The results showed this population of genetic variations of 647 fine-wool sheep was in the medium level.GG and AA genotype in the crimp number of the individual value was significant higher than GA genotype on SNP1(P<0.05).TC genotype in the mean fiber diameter of the individual value was significant higher than TT and CC genotype on SNP2(P<0.05).TT and CC genotype in the greasy fleece weight of the individual value was significant higher than TC genotype on SNP2(P<0.05).There were 9 different combined genotypes in SNP1 and SNP2 by combination effect.AATT combined genotype in the greasy fleece weight of the individual value was extremely significant higher than AACC combined genotype(P<0.01),GGTC and AATC combined genotype in the greasy fleece weight of the individual value were extremely significant higher than AACC combined genotype(P<0.01),While,other combined genotypes in the greasy fleece weight were significance difference(P<0.05).