The ontogeny of nutrient transporter and digestive enzyme gene expression in domestic pigeon (Columba livia) intestine and yolk sac membrane during pre- and posthatch development

Abstract

To better understand the digestive capacity in domestic pigeons (Columba livia), this study was conducted to evaluate nutrient transporters and digestive enzymes gene expression in small intestine and yolk sac membrane (YSM) during pre- and posthatch development. We investigated the oligopeptide transporter Pept1, sodium glucose transporter SGLT1, glucose transporter GLUT2, aminopeptidase-N (APN), and sucrase-isomaltase (SI). Intestine was collected at embryo d 12, 14, and 16, day of hatch, and d 1, 3, 5, 8, and 14 posthatch. The YSM was collected at embryo d 12, 14, 16, and day of hatch. The cDNA fragments for Pept1, SGLT1, GLUT2, APN, and SI were isolated and cloned using reverse-transcription PCR. The sequences data showed that these genes were highly identical to the gene of chicken. The mRNA expression of each gene was assayed using real-time PCR. Expression of intestinal nutrient transporters increased linearly (P<0.001) with age whereas that of APN increased quadratically (P<0.001) and SI increased cubically (P=0.001). Levels of PepT1 mRNA were greatest in the duodenum (P=0.001), GLUT2 and SGLT1 mRNA were greatest in the jejunum (P=0.002) and APN were greatest in the ileum (P=0.004). The YSM expressed all the examined genes. The YSM-expressed genes decreased between embryo d 16 and day of hatch, whereas intestine-expressed genes increased. Our findings provide a comprehensive profile of gene expression patterns of nutrient transporter and digestive enzyme in the small intestine and YSM of pigeons and establish a foundation for future research on the nutrients requirements for young pigeons.