title: Developmental regulation of nutrient transporter and enzyme mRNA abundance in the small intestine of broilers.
abstract: The objective of this study was to investigate intestinal nutrient transporter and enzyme mRNA in broilers selected on corn- and soybean-based (line A) or wheat-based (line B) diets. We investigated the peptide transporter PepT1, 10 amino acid transporters (rBAT, b(o,+)AT, ATB(o,+), CAT1, CAT2, LAT1, y(+)LAT1, y(+)LAT2, B(o)AT, and EAAT3), 4 sugar transporters (SGLT1, SGLT5, GLUT5, and GLUT2), and a digestive enzyme (aminopeptidase N). Intestine was collected at embryo d 18 and 20, day of hatch, and d 1, 3, 7, and 14 posthatch. The mRNA abundance of each gene was assayed using real-time PCR and the absolute quantification method. For PepT1, line B had greater quantities of mRNA compared with line A (P = 0.001), suggesting a greater capacity for absorption of amino acids as peptides. Levels of PepT1 mRNA were greatest in the duodenum (P < 0.05), whereas the abundances of SGLT1, GLUT5, and GLUT2 mRNA were greatest in the jejunum (P < 0.05). Abundances of EAAT3, b(o,+)AT, rBAT, B(o)AT, LAT1, CAT2, SGLT5, and aminopeptidase N mRNA were greatest in the ileum (P < 0.05). Quantities of PepT1, EAAT3, B(o)AT, SGLT1, GLUT5, and GLUT2 mRNA increased linearly (P < 0.01), whereas CAT1, CAT2, y(+)LAT1, and LAT1 mRNA decreased linearly (P < 0.05) with age. Abundance of y(+)LAT2 mRNA changed cubically (P = 0.002) with peaks of expression at day of hatch and d 7, and aminopeptidase N and SGLT5 mRNA changed quadratically (P = 0.005) with age. These results provide a comprehensive profile of the temporal and spatial expression of nutrient transporter mRNA in the small intestine of chicks.
authors.affiliation: Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA.
authors.forename: E R
authors.initials: ER
authors.lastname: Gilbert
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: D A
authors.initials: DA
authors.lastname: Emmerson
authors.forename: K E
authors.initials: KE
authors.lastname: Webb
authors.forename: E A
authors.initials: EA
authors.lastname: Wong
mesh_terms: D000375:Aging; D026905:Amino Acid Transport Systems / Q000235:genetics* / Q000378:metabolism; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000235:genetics* / Q000254:growth & development*; D004032:Diet / Q000662:veterinary; D005786:Gene Expression Regulation / Q000235:genetics*; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000201:enzymology / Q000254:growth & development; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D009004:Monosaccharide Transport Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D026905:Amino Acid Transport Systems; D026901:Membrane Transport Proteins; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; C043912:peptide permease