肉鸡肠道PepT1 mRNA表达的肠段差异性与发育性变化

Regional and Ontogenetic Expression of PepT1 mRNA in Intestine of Broiler

选用遗传背景相同的1日龄父母代雄性Arbor Acre（AA）鸡和父母代雄性岭南黄肉雏鸡各120羽,采用相对定量RT-PCR方法,以30 d时岭南黄鸡肠道样品为模板,研究肉鸡肠道寡肽转运载体1（Peptide transporter 1,PepT1）mRNA表达的肠段差异性;以AA肉鸡和岭南黄鸡十二指肠和空肠样品为模板,研究不同品种肉鸡肠道PepT1 mRNA表达的发育性变化.结果显示：（1）岭南黄肉鸡肠道PepT1 mRNA的表达丰度从十二指肠、空肠、回肠到结直肠依次降低,其中十二指肠显著高于结直肠（P＜0.05）;（2）AA鸡和岭南黄肉鸡PepT1 mRNA在十二指肠及空肠中的表达具有相同的发育模式,16 d表达丰度最高,16～44 d逐渐下降,58 d略微回升;不同基因型之间PepT1 mRNA丰度比较,AA鸡和岭南黄肉鸡两品种间PepT1 mRNA的表达没有显著差异（P＞0.05）.以上结果说明：（1）随着肠道空间位置的后移,岭南黄肉鸡肠道PepT1 mRNA的表达丰度逐渐降低,其中十二指肠的表达丰度显著高于结直肠（P＜0.05）;（2）不同品种肉鸡十二指肠及空肠PepT1 mRNA的表达具有相同的发育模式,且同日龄两品种间的表达丰度未见明显差异,表明PepT1 mRNA表达受到发育阶段的调控,但品种间具有稳定性.

120 1-day-old parental male Arbor Acre （AA） broiler and 120 1-day-old parental male Lingnan yellow broiler were randomly divided into 4 replicates, respectively. Regional expression of Peptide transporter 1 （PepT1） mRNA in different intestinal tract segments of Lingnan yellow broiler on 30 d and ontogeny of PepT1 mRNA in duodenum and jejunum of AA broiler and yellow broiler were determined by relative quantitative RT-PCR. The results showed that： （1） Regional expression of PepT1 mRNA in duodenum, jejunum, ileum and colorectum was declined gradually. The abundance of PepT1 mRNA in duodenum was higher than in colorectum （P〈 0.05）; （2）Ontogeny patterns of PepT1 mRNA in duodenum and jejunum were consistent between AA broiler and Lingnan yellow broiler. The abundance of PepT1 mRNA in two strains was the highest on day 16, decreased from day 16 to day 44 and slightly increased again on day 58. While compared two breeds directly, the abundance of PepT1 mRNA in AA broiler was not significant difference than that in Lingnan yellow broiler from day 2 to day 58（P〉0.05）. These results indicated that： （1） Regional expression of PepT1 mRNA in intestine of Lingnan yellow broiler was declined gradually along the downward intestine from duodenum, jejunum, and ileum to colorectum. The abundance of PepT1 mRNA in duodenum was higher than in colorectum （P 〈0.05） . （2） Ontogeny of PepT1 mRNA in two breeds had the same pattern in duodenum and jejunum, and there was no difference at same development stage between AA broiler and Lingnan yellow broiler, indicating that PeptT1 mRNA expression could be regulated by developmental stage but not breeds.