Study On The MRNA Expression Of T1R1/R1R3and PepT1Gene In Luxi Bovine Gastrointestinal Tract

The amino acid nutritional needs of ruminants has been a hot and difficult subject.As Rumen microbes will degradate some amino acid that ruminants intake, and themetabolism and the production of amino acid requirements influenced by thephysiological state and the level of production, so researchers were difficult toaccurately determine the requirement of amino acid. Amino acids played an importantrole in production performance of ruminants，so this problem became a acute issue.Thedifficulty of the determination of amino acid nutritional needs was performance in thetheoretical and technical aspects. As for theoretical difficulty, that the regulatorymechanism of the absorption of amino acids and amino acid balance in the body is notfully clear are the mainly problem.T1Rs plays an important role in the identification of amino acids, which is theamino acids are ligands of T1R3. The increasing number of experiments show thatT1R1and T1R3expressed in taste buds, but that also expressed in the gastrointestinaltract, and they participated in the regulation of the amino acid as heterodimer. ThemRNA expression of T1R1/T1R3in the Luxi bovine gastrointestinal tract wasinvestingated by relative quantification PCR.Amino acids can be transported across the brushborder membrane of intestinalepithelial cells either in their free form by a variety of different AA transporters thatvary in substrate specificity or in the form of di-and tripeptides by the broad-specificitypeptide transporter, PepT1. So we also determined the PepT1gene quantity in the Luxibovine gastrointestinal tract.The results were as follows:1、The mRNA expression of T1R1gene in the Luxi bovine gastrointestinal tractIn this study, the mRNA expression of T1R1in the Luxi bovine gastrointestinaltract were first investingated by relative quantification PCR. According to the results ofRT-PCR, we listed the tissues according to priority of T1R1mRNA quantity as follows:Jejunum (29.34), ileum (23.25), rumen (21.50), reticulum (15.95), duodenal (11.01),omasum (4.53), abomasum (3.00), cecum (1.20), pancreas (1.00), colonic (0.98) andrectum (0.96), with the differences being significant(P<0.05); the gene quantity was highest in Jejunum, with insignificant difference to ileum and rumen (P>0.05) andextremely significant difference to reticulum, duodenal, omasum, abomasums, cecum,pancreas, colonic and rectum (P<0.05). T1R1mRNA quantity in ileum wasinsignificantly different to rumen and reticulum (P>0.05), with significant differencebetween duodenal, omasum, abomasums, cecum, pancreas, colonicand rectum(P<0.05).There is nosignificant difference among duodenal, omasum, abomasums,cecum, pancreas, colonic and rectum (P>0.05).2、The mRNA expression of T1R3in the Luxi bovine gastrointestinal tractAs for T1R3mRNA aboundance in the Luxi bovine gastrointestinal tract, theresult was jejunal (29.34), ileum (23.25), rumen (21.50), reticulum (16.50), duodenal(10.98), omasum (4.51), abomasum (3.03), cecum (1.20), pancreas (1.00), colonic (1.00)and rectum (0.96), with the differences being significant(P<0.05);the gene quantity washighest in Jejunum, with nosignificant difference to ileum and rumen (P>0.05) andextremely significant difference to reticulum, duodenal, omasum, abomasums, cecum,pancreas, colonic and rectum (P<0.05). T1R3mRNA quantity in ileum wasnosignificantly different to rumen and reticulum (P>0.05), with significant differencebetween duodenal, omasum, abomasums, cecum, pancreas, colonic and rectum(P<0.05), there is nosignificant difference among duodenal, omasum, abomasums,cecum, pancreas, colonic and rectum (P>0.05).3、The mRNA expression of pepT1in the Luxi bovine gastrointestinal tractAccording to the results of RT-PCR, we listed the tissues according to priority ofpepT1mRNA quantity as follows: jejunal (29.84), ileum (24.24), rumen (22.07),reticulum (16.01), duodenal (11.36), omasum (4.56), abomasum (3.13), cecum (1.20),pancreas(1.00), colon(1.00), rectum(0.99), with the differences beingsignificant(P<0.05).The pepT1gene quantity was highest in Jejunum, with insignificantdifference to ileum and rumen (P>0.05) and extremely significant difference toreticulum, duodenal, omasum, abomasums, cecum, pancreas, colonic and rectum(P<0.05). pepT1mRNA quantity in ileum was insignificantly different to rumen andreticulum(P>0.05),with significant difference between duodenal, omasum, abomasum,cecum, pancreas, colonic and rectum (P<0.05); there is insignificant difference amongduodenal, omasum, abomasums, cecum, pancreas, colonic and rectum (P>0.05). 4、The mRNA expression of T1R1、T1R3and pepT1in the same tissues of Luxibovine gastrointestinal tractT1R1, T1R3and pepT1mRNA quantity in jejunal was29.34,29,34,29.84. T1R1,T1R3and pepT1mRNA quantity in ileum was23.25,23.25,24.24. T1R1, T1R3andpepT1mRNA quantity in rumen was21.50,21.50,22.07. T1R1, T1R3and pepT1mRNAquantity in reticulum was15.95,16.50,16.01. T1R1, T1R3and pepT1mRNA quantity induodenal was11.01,10.98,11.36. T1R1, T1R3and pepT1mRNA quantity in omasum4.53,4.51,4.56. T1R1, T1R3and pepT1mRNA quantity in abomasum3.00,3.03,3.13.T1R1, T1R3and pepT1mRNA quantity in cecum1.20,1.20,1.20. T1R1, T1R3andpepT1mRNA quantity in pancreas1.00,1.00,1.00. T1R1, T1R3and pepT1mRNAquantity in colon0.98,1.00,1.00. T1R1, T1R3and pepT1mRNA quantity in rectum0.96,0.96,0.99.From the above results, we can initially speculated that the T1R1/T1R3andpepT1expression in Luxi bovine gastrointestinal tract. we can also conclude that therelative expression differences of the T1R1/T1R3and pepT1in various tissues of theLuxi bovine gastrointestinal tract is consistent. The tissue which the mRNA relativeexpression of T1R1/T1R3was also expessed high level of pepT1. we hypothesized thatT1R1/T1R3binded amino acid that ruminants intake to activat the function of pepT1.