Heritable Variation And Tissue Expression Pattern Analysis Of Foxo1Gene In Qinchuan Cattle

As a protein molecule that control gene expression, transcription factor regulation of the body’s growth and metabolism through regulating the expression of target gene. Transcription factor FoxO as an important member of the Fox family, mainly through the PI3K/Akt pathway to regulate the transcriptional activity, and forkhead transcription factor （FoxO1） is the first identified member of the FoxO subfamily, it mainly involve myoblast differentiation and fat cell metabolism, and as a potential factor involved in skeletal muscle differentiation and I muscle fiber type gene expression, So it is an important candidate factors for the study of muscle and adipose tissue development and metabolic.The Qinchuan cattle are a famous breed in meat and draught belonging to the Huanghuai group and found in central Shaanxi in China. The tests were carried out research and analysis in structure and function of FoxO1gene in Qinchuan cattle from the following four aspects.1) Genetic variation of FoxO1gene in Qinchuan cattle.We detected the genetic variations of FoxO1gene through DNA pools sequencing techniques within488individuals in Qinchuan cattle. In these four locis, we detected5mutations （NC₀07310.5:SNP A176183G, SNP C1071T, SNP G1200A, SNP C1245A and SNP G1732A）. Moreover, the mutations SNP C1071T, SNP G1200A, SNP C1245A and SNP G1732A located in exon3, while the mutation SNP A176183G was located in intron2. Three of them revealed three synonymous mutations:SNP C1071T （Ala> Ala）, SNP G1200A （Pro> Pro）, SNP C1245A （Pro> Pro）, One is missence mutation:SNP G1732A（Ala>Thr）.2) The association analysis between polymorphic and growth trait of FoxO1gene in Qinchuan cattle.Through the genetic diversity analysis of FoxO1gene, we calculated the gene （genotype） frequency of the five mutations, and at the SNP A176183G, G1200A, C1245A and G1732A loci, the QC cattle belonged to intermediate genetic diversity, and SNP G1200A, SNP C 1245A and SNP G1732A in accordance with Hardy-Weinberg equilibrium by χ2test. In addition, we reported haplotype variability, extent of linkage disequilibrium （LD） and correlation analysis in488individuals in Qinchuan cattle. Haplotype analysis of five SNPs showed that24different haplotypes were identified in all, whereas only7haplotypes were listed except those frequency<0.03and Hap5（-GCACG-） had the highest haplotype frequencies （28.40%）. LD analysis showed that SNP C1071T and G1200A, G1200A and C1245A loci were in strong linkage （r2>1/3, D’>0.7）. Correlation analysis showed that, in SNP A176183G mutation, three genotypes had significant association with body length, chest breadth and chest depth in Qinchuan population （P<0.05）; In SNP C1071T mutation, three genotypes had no significant association with ten growth traits in Qinchuan population （P>0.05）; In SNP G1200A mutation, three genotypes had significant association with rump length in Qinchuan population （P<0.05）; In SNP C1245A mutation, three genotypes had significant association with chest breadth and chest depth in Qinchuan population （P＜0.05or P<0.01）; In SNP G1732A mutation, three genotypes had significant association with body length, rump length, withers heights and hucklebone width in Qinchuan population （P<0.05or P＜0.01）.3) Bioinformatics analysis of FoxO1gene in Qinchuan cattle.We also used bioinformatics methods to carry on the forecast analysis of the structure and function of FoxO1protein,such as physicochemical properties, hydrophobicity, phosphorylation sites, transmembrane domain, subcellular localization, signal peptide, disulfide bond, secondary structure and conserved domain.It turned out that, FoxO1protein is the unstable acidic and the hydrophilic protein,having phosphorylation site, and no transmembrane regions; FoxO1protein mainly located in nucleus, secondly in the cytoplasm, and having no signal peptide; it is non secretory protein, and there are seven cysteine residues, including six cysteine form three disulfide bond; In the secondary structure, the proportion of random curl is as high as75.42%, alpha helix take second place at17.30%, and Forkhead domain has95conservative amino acid residues between amino acids165-259.4) Tissue expression pattern analysis of FoxO1gene in Qinchuan cattle.We adopted the real-time quantitative PCR to detection the expression quantity of FoxO1gene in different periods （fetal bovines, calves and adult cattle） and different tissues （heart, liver, spleen, lung, kidney, stomach, intestines, fat, muscle） of Qinchuan cattle. As a result, we detected the expression quantity of FoxO1gene in the all tissues except intestines and fat in adult cattle, and all tissues have the highest expression quantity in Qinchuan calves in addition to heart tissue in fetal period. The relative expression quantity was high in heart tissue as compared with other tissues in fetal bovines. The relative expression quantity was high in liver tissue as compared with other tissues in calves. The relative expression quantity was high in spleen tissue as compared with other tissues in adult cattle. This also shows that the expression patterns of FoxO1gene are different at different developmental stages and different tissues in Qinchuan cattle.