Association Analysis Of NCAPG,DCAF16,FAM184B,TBX3 Gene Polymorphisms And Early Growth Traits In Dezhou Donkeys

Dezhou donkey,as a large concurrent breed in China,has good meat performance,but its molecular genetic breeding research foundation is relatively weak.Therefore,NCAPG,DCAF16,FAM184 B and TBX3 genes related to animal growth and development were selected as candidate genes to excavate molecular markers related to growth traits of Dezhou donkeys,which could provide important reference and guidance for donkey molecular marker-assisted selection breeding.The SNPs of these genes were detected by DNA pool sequencing in 227 donkeys from Dezhou.SNP was genotyped by mass spectrometry.Genotype frequency and allele frequency were calculated by genotyping statistics.Genetic parameters and Hardy-Weinberg equilibrium were tested by using Excel2010.Haploview 4.2 software was used to analyze linkage disequilibrium and haplotype according to SNP location and genotype information.The association between genetic polymorphisms and growth traits at birth,3-month and 6-month was analyzed by general linear model(GLM)of SPSS 24.0software.The results show that:(1)Mixed pool sequencingT ? C transformation(rs1)took place in intron 9 of NCAPG gene.Peak map of rs1 reverse sequencing complementarity with T?C.A?G transformation(rs2)took place in intron 11.A C?G mutation(rs4)was found in intron 19,a C ? G mutation(rs5)in intron 8.Mutation of A ? G was detected in a repeat sequence of exon 2 of DCAF16 gene(rs008).An A?C single base mutation(rs46)was found in intron 7 of FAM184 B gene,and mutation of G?A(rs031)was found in exon 18.In the TBX3 gene,rs7 locus G?A was located in the upstream regulatory region of the gene,and an A?G mutation(rs8)was found in the intron 2.(2)Analysis of association between genetic polymorphisms and growth traitsThe average rump length of the initial stage of the rs1 locus genotype CC was significantly higher than that of the CT genotype by 1.03 cm(P<0.05).The average chest width of TT genotypes in Dezhou donkeys at 6 months was increased by 1.51 cm compared with CC genotype,reaching a highly significant level(P<0.01).The average tube circumference of CT and TT genotypes was significantly higher than CC(P<0.05).The correlation analysis of rs4 locus revealed that the average chest depth of Dezhou donkeys at birth with GG genotype was significantly higher than GC(P<0.05);the average chest width and tube circumference with CC genotype at 6 months of age were higher than GG significantly in Dezhou donkeys(P<0.05).The results of rs008 locus correlation analysis showed that the average body weight of AA genotypes was significantly increased by 5.33 kg and the body height was increased by 2.46 cm,and the height difference also reached a significant level,with a difference of 1.99 cm(P<0.05);the average body weight of the GA genotype of the rs008 locus in Dezhou donkeys was significantly higher than the GG by 4.91 kg,and the height and height of the rump were significantly increased by 2.1 cm and 1.93cm(P<0.05).At 6 months of age,the average height and chest circumference of individuals with AA and GA genotypes were extremely significantly higher than those of GG genotypes(P<0.01).The chestdepth and rump height of GA genotypes were significantly higher than those of GG genotypes(P<0.01).P<0.01),and the average rump width of the GA genotype of Dezhou donkeys was significantly higher than that of GG and AA genotypes(P<0.05).According to linkage disequilibrium analysis,there were five combinational genotypes of rs1,rs2,rs4 and rs5 loci in Dezhou donkey population.The results of correlation analysis showed that the average chest width of Dezhou donkeys with TTAACCCC genotype was higher than the CCGGGGGG at 6 months of age(P<0.05).The results of association analysis between rs7 and growth traits in TBX3 gene showed that the average circumference of AA genotype individuals was significantly higher than that of GG genotype individuals at the age of 3 months(P<0.05),and the average rump width of GA genotype individuals was significantly higher than that of AA genotype individuals(P<0.05);at the age of 6 months,the average rump width of GA and GG genotype was higher than the AA significantly in Dezhou donkeys(P<0.05).