Association Analysis Of PepT1Gene Polymorphism With Feed Conversion Rate In Chongren Spotty Chicken And PepT1Gene Expression In The Small Intestine

Part1:60-120d Chongren spotty chickens were used as test material and primers weredesigned according to the sequence of PepT1gene. Then single nucleotide polymorphismsof PepT1gene were detected by PCR direct sequencing and its genotype were analyzed byread-through of DNA sequence along with the identification of its peak chart, which aimsto explore the relationship between PepT1gene polymorphism and feed conversion rate inChongren spotty chickens. Three SNP locus were found and they were completely silentmutations. A single base was transformed (G→A) on95st spot of exon4in PepT1, leadingto three genotypes: AA,AB and BB. And another two mutations, which were provedidentical, were detected on64st spot and70st spot of exon6of PepT1gene (C→G andA→G, respectively), leading to two genotypes: AA and AB. By analyzing PepT1genepolymorphism with POPGENE32software, PV1’s polymorphic locus was moderate andthat of PV2was low, although they were in Hardy-Weinberg equilibrium. Correlationanalysis between SNPs genotype of PepT1gene and feed conversion rate was carried outthrough Spass17.0and showed that three genotypes in PV1and two genotypes in PV2ofPepT1gene were not significantly correlated with feed conversion rate (P>0.05).Part2: This experiment was conducted to discover its expression of PepT1mRNA inChongren Spotty Chicken intestine in order to support the study on the mechanism oftransporting small peptide through small intestine and the distribution of peptidetransporters. Samples obtained from intestine of120-day old Chengren Spotty Chickenwere performed with real-time fluorescent quantitative PCR to study the differentialexpression of peptide transporter1(PepT1) mRNA in different intestinal segments and inbreeds with different feed conversion rate. Data showed that the abundance of PepT1mRNA gradually decreased from duodenum to jejunum and ileum, the expression ofPepT1mRNA in duodenum was significantly higher than that in ileum (P<0.01), but therewas no significant difference in the abundance of PepT1mRNA between duodenum andjejunum or between jejunum and ileum (P>0.05). The abundance of PepT1mRNA frombreed with high feed conversion rate was numerically higher than that form breed with lowfeed conversion rate (P>0.05). while the results in jejunum and ileum are opposite and theexpression difference of PepT1mRNA has no significant (P>0.05).