不同基因型肉鸡十二指肠SGLT1和GLUT2 mRNA表达的发育性变化

选用遗传背景相同的1 d父母代雄性Arbor Acre (AA)和岭南黄肉雏鸡各120羽，饲养58 d，统计其生产性能并在不同时间采集十二指肠样品，采用相对定量RT-PCR方法研究不同基因型肉鸡在不同时期十二指肠钠葡萄糖共转运载体1(sodium/glucose cotransporter1, SGLT1) 和葡萄糖转运载体2(glucose transporter2, GLUT2) mRNA的表达丰度。结果显示： ①AA鸡每周平均日采食量(ADFI)和平均日增重(ADG)均显著高于黄羽肉鸡(P＜0.05)。②AA鸡和黄羽肉鸡SGLT1 mRNA表达，从2～30 d不断升高，44 d下降，55 d回升；不同基因型之间SGLT1 mRNA丰度比较，AA鸡均高于黄羽肉鸡，且在16和30 d差异显著(P＜0.05)。③AA鸡和黄羽肉鸡GLUT2 mRNA的表达在2～30 d呈现升高的趋势，且16和30 d均显著高于2 d(P＜0.05)；AA鸡44和58 d GLUT2 mRNA的表达显著低于16和30 d(P＜0.05), 而黄羽肉鸡GLUT2 mRNA的表达，58 d显著高于2、16和30 d(P＜0.05)；不同基因型之间GLUT2 mRNA丰度比较，16和30 d AA鸡显著高于黄羽肉鸡(P＜0.05)，58 d时黄羽肉鸡GLUT2 mRNA的表达显著高于AA鸡(P＜0.05)。以上结果说明，AA鸡生产性能显著高于黄羽肉鸡，营养水平的改变对动物生产性能有较大影响，AA鸡的反应比黄羽肉鸡更敏感; 不同基因型肉鸡十二指肠SGLT1 mRNA的表达具有相同的发育模式，且与生产性能的表现相一致；更换饲料下调SGLT1 mRNA的表达，提示调控SGLT1的表达，可以改善生产性能; 生长发育后期黄羽肉鸡GLUT2 mRNA的表达模式，是其有别于AA肉鸡的重要特征。

Ontogenetic Expression of SGLT1 and GLUT2 mRNA in Duodenum of Different Genotype Broiler Chicken

In order to investigate the ontogenetic expression of sodium/glucose cotransporter1(SGLT1) and glucose transporter2 (GLUT2) mRNA in duodenum of different genotype broiler chickens, 120 1-day-old parental male Arbor Acre (AA) broiler chickens and 120 parental male yellow cover chicks were randomly divided into 4 replicates, respectively. The productive performance was recorded from day 1 to 58 d. On 2,16,30,44 and 58 d, duodenum samples were collected. The mRNA expression abundances of SGLT1 and GLUT2 at different developmental stage were determined by relative quantitative RT-PCR. It was found that: (1) The average daily feed intake (ADFI) and average daily gain (ADG) of every week of AA chicken were higher than that of yellow cover chicken (P <0.05) , the change curve of every week ADFI and ADG were similar between the two genotypes. (2) Ontogenetic expression model of SGLT1 mRNA were consistent between AA broiler and yellow cover chicken. The SGLT1 mRNA abundance in the two genotypes were increased from day 2 to day 30, then decreased on day 44 and increased again on day 58. The SGLT1 mRNA expression level of AA chicken was higher than that of yellow cover chicken and the differences were significant on day 16 and 30 (P<0.05). (3) GLUT2 mRNA expression of the two genotypes trended to increase from day 2 to day 30, and the abundance of day 16 and 30 were higher than that of day 2 at significant level (P <0.05). On day 44 and day 58, the GLUT2 mRNA expression of AA broiler were lower than that on day 16 and 30 (P <0.05), while the expression of yellow cover chicken was going on increasing from day 44 to day 58 and GLUT2 mRNA expression abundance of day 58 was higher than that on day 2,16 and 30; Compared GLUT2 mRNA expression with yellow cover chicken, AA broiler was higher on day 16 and 30 (P <0.05), while on day 58 yellow cover chicken GLUT2 mRNA expression was higher than that of AA chicken. These results demonstrate that: 1) Productive performance of AA broiler chicken excells yellow cover chicken. The alteration of nutritional level has great effect on the performance and the AA broiler chicken is more sensitive than yellow cover chicken. 2) SGLT1 mRNA expression of the two genotype has the same ontogenetic model in duodenum and paralleled with the productive performance. To change diet can decrease the expression of SGLT1 mRNA, indicating that the productive performance can be improved by up-regulating of SGLT1 expression. 3) GLUT2 mRNA expression ontogenetic model of late-finishing yellow cover chicken is distinct with AA chicken, and its mechanism and effect on production needed further study.