Document Type

Thesis - University Access Only

Award Date

2002

Degree Name

Master of Science (MS)

Department / School

Veterinary and Biomedical Sciences

Abstract

Galectins are an evolutionarily conserved family of carbohydrate-binding proteins found in a wide variety of tissues and cells. To date, there are 14 members of the galectin family. The biological functions of these lectins are largely undefined. The research goal was to characterize the galectins found in porcine small intestine. First, we identified the galectins expressed in the porcine intestine using both a biochemical and a molecular biology approach. Galectin-4 is the main lactose-binding protein produced in the small intestine. The molecular biology approach also identified galectin-4, and a shorter version of galectin-4 that was missing a string of nine amino acids, as being produced by porcine small intestine. We then wanted to determine where galectin-4 naturally occurs in porcine small intestine. Galectin-4-specific monoclonal antibodies were designed in our laboratory for use in immunohistochemistry (IHC), and galectin-4-specific oligonucleotide probes were designed for use in in-situ hybridization (ISH) studies. Results from both IHC and ISH studies demonstrated that galectin-4 is expressed at high levels in the absorptive epithelial cells lining the lumen of the intestine, and not in other layers of the intestine or in the goblet cells. The highest level of expression of galectin-4 was observed in epithelial cells at the villous tips, with progressively less galectin-4 expressed along the villi and the crypts. Among the cells in the intestinal crypts, a specific subset of cells appearing to be enteroendocrine cells due to the presence of basal granules express galectin-4 at an exceptionally high level. These same characteristics of galectin-4 expression were observed in all three regions (duodenum, jejunum, and ileum) of the small intestine.

Library of Congress Subject Headings

Swine Lectins Intestine, Small Protein binding

Format

application/pdf

Number of Pages

79

Publisher

South Dakota State University

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