| Feed efficiency is one of the main factors determining the cost of animal production,which has gradually attracted extensive attention from animal genetics and breeding experts at home and abroad.At present,Residual Feed Intake(RFI)has been widely used in the evaluation of Feed efficiency of livestock and poultry,and the gene positioning of RFI has become the focus of molecular breeding.The Tan sheep industry in Ningxia is developing gradually,and the proportion of the Tan sheep to market is gradually increasing,but the research on the feed efficiency of Tan sheep is still relatively limited.Therefore,in this study,extreme RFI Tan sheep were resequenced and 50K chip sequenced,and Genome wide association study(G WAS)was conducted for RFI traits of Tan sheep to determine the loci and candidate genes affecting RFI of Tan sheep.1.Resequencing with 30 X sequencing depth was carried out using IIlumina’s high-throughput sequencer.Determination of 30 extreme RFI Tan sheep individuals,after quality control of the original data,22 240 774 SNPs were obtained.The mixed linear model was used to conduct GWAS,and 500 SNPs were found to be related to RFI traits of Tidal sheep,and 126 known genes were annotated.GO and KEGG functional enrichment analysis of the annotated genes showed that the annotated genes were enriched in relation to cell cycle,PI3K-Akt signaling pathway and insulin signaling pathway.KASP technology was used to determine the genotypes of population loci,and it was found that Chr1:30939091、Chr3:82327573、Chr3:107340609、Chr10:34812026、Chr10:35052741、Chr16:42388856、Chr18:18500330、Chr21:22853482、Chr22:55007345 loci had different genotypes on THE RFI traits of Tan sheep.In Chr16:42388856 locus,CC was the dominant genotype and C was the dominant allele.RFI of Tan sheep of CC genotype was significantly lower than that of GC and GG genotypes(P<0.01).Chr18:CG was the dominant genotype and G was the dominant allele at locus 18500330.RFI of Tan sheep of GG genotype was significantly higher than that of Tan sheep of CC genotype(P<0.01).Combined with their corresponding genes,RT-qPCR verification showed that ADAMTS12 and PLIN1 genes corresponding to CHR16:42388856 and CHR18:18500330 were significantly different in the expression of extremely high RFI and extremely low RFI Tan sheep(P<0.05),which could be used as candidate genes for RFI Tan sheep.2.The 50K chip for sheep designed by Compson Company was used to measure 292 individuals,with an average of 64 734 SNPs in each individual.GWAS was conducted by mixed linear model,and 62 significant SNPs were found to be related to RFI traits of Tan sheep,and 100 known genes were annotated.The functional enrichment analysis of GO and KEGG showed that the annotated genes were mainly related to amino acid metabolism,and three different genotypes of Chr4:127201684,Chr2:246817664,and Chr19:58673493 affected THE RFI of Tan sheep.There were significant differences in RFI traits among the three genotypes at Chr4:127201684.The RFI of Tan sheep of AA genotype was significantly higher than that of GG genotype(P<0.01),and that of AG genotype(P<0.05),and the GG average RFI of dominant genotype was the lowest.Chr2:TC at 246817664 locus was the dominant genotype and C was the dominant allele.RFI of Tan sheep of TT and TC genotypes was significantly higher than that of Tan sheep of CC genotypes(P<0.01).Chr19:GG was the dominant genotype at 586 73493,and G was the dominant allele.RFI of Tan sheep with GG genotype was significantly lower than that of AA and AG genotypes(P<0.05).RtqPCR results showed that the expression of INSIG1,PID1 and PPARG corresponding to Chr4:127201684,Chr2:246817664 and Chr19:58673493 was significantly different in extremely high and extremely low RFI Tan sheep(P<0.05).It can be used as a candidate gene for RFI of Tan sheep.The GWAS study on the RFI traits of Tan sheep in this study provided a research basis for improving the growth performance of Tan sheep,and the candidate genes for Tan sheep and RFI traits were mined from the genome level. |
PDF Full Text Request