September 11th, 2004
International Society for Animal Genetics Conference, 2004, Tokyo, Japan. Abstract C 007.
The objective of this study was to compare the effects of diet and age on gene expression profiles of villus and crypt intestinal cell populations in the canine. Twelve geriatric (12 yr old) and 12 young adult (1 yr old) beagles were used. Six dogs from each age group were randomly assigned to one of two dietary treatments: 1) high quality, animal-protein based diet, or 2) plant-based diet. Intestinal tissues were collected after animals had been on experiment for one year. Laser capture microdissection (LCM) was used to isolate individual villus and crypt epithelial cells from ileal samples. RNA was isolated and amplified using the PicoPureTMRNA Isolation Kit and RiboAmp®OA RNA Amplification Kit (Arcturus), respectively. Gene expression profiles were generated by hybridizing amplified RNA to the Affymetrix GeneChip® Canine Genome Arrays. Preliminary results show that genes more highly expressed in the crypt epithelial cells include genes related to apoptosis, cell cycle, DNA replication, and energy metabolism. In contrast, genes more highly expressed in villus than crypt were associated with matrix or structural proteins. The use of LCM provides cell-specific gene expression profiles of distinct intestinal cell populations. While villus cells are composed of differentiated cell populations possessing specific functions, crypt regions are composed of undifferentiated cells. Research in this area may identify factors associated with cellular differentiation and lead to the development of therapies for intestinal disease and may be used as a screening tool for gene targets associated with growth promotion. (Supported by Pyxis Genomics, Inc. and the Critical Research Initiative (CRI) at the University of Illinois).