Gene Expression of Nutrient Transporters and Digestive Enzymes in the Yolk Sac Membrane and Small Intestine of the Developing Embryonic Chick

Chick embryos derive nutrients from the yolk during incubation and transition to intestinal absorption posthatch. Nutrient uptake is mediated by digestive enzymes and membrane bound transporter proteins. The objective of this study was to determine expression profiles of nutrient transporters and digestive enzymes during incubation in the yolk sac membrane (YSM) and small intestine of Leghorn and Cobb chickens derived from 22–30 wk (young) and 45–50 wk (old) breeder flocks. Genes examined included peptide transporter PepT1, amino acid transporters EAAT3, CAT1, and B0AT, monosaccharide transporters SGLT1 and GLUT5, and digestive enzymes APN and SI. Expression of these genes was measured in YSM at embryonic day (e) 11, 13, 15, 17, 19, 20, and 21 and small intestine at e15, e17, e19, e20, and e21. Absolute quantification real-time PCR assessed gene expression. PepT1, APN, and B0AT expression in YSM peaked between e15 and e17 and then decreased until e21, while expression increased over time in the small intestine. SGLT1 and EAAT3 expression increased over time in the small intestine and YSM. There was minimal gene expression of SI in the YSM, while the small intestine had high expression. GLUT5 and CAT1 expression decreased in the YSM, while peaking at e19 then decreasing in the small intestine. Breed and flock age affected expression levels in some genes. These results demonstrate that these genes show tissue- and development-specific patterns of expression and that the YSM expresses many digestive enzymes and nutrient transporters associated with the small intestine.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Animal and Poultry Sciences

Department dc:contributor.department

Animal and Poultry Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2011

Author dc:creator

• Speier, Jacqueline S.

Chair dc:contributor.committeechair

• Wong, Eric A.

Committee members dc:contributor.committeemember

• Dalloul, Rami A.
• McElroy, Audrey P.

• Digestive Enzymes
• Nutrient Transporters
• Intestine
• Yolk Sac Membrane

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-08162011-124927

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/44254