Modeling Human Intestinal Disease: Ontogeny Of Postembryonic Zebrafish Intestinal Morphology

The goal of this study was to establish zebrafish as a model organism for intestinal motility disorders in humans. Zebrafish provide a high throughput model that allows for the examination of the intestine throughout the life of an organism. While the zebrafish intestine shares a high degree of morphological homology with the human intestine, little is known about the maturation process. To begin to understand the maturation of the intestine, I characterized its appearance throughout the larval period and into metamorphosis. I found that the onset of metamorphosis coincides with a minimum standard length that ranges from 4.4 to 5.2 mm. Using a stage range of larval and metamorphic specimens, I used histological methods to follow the distribution of goblet cells, the mucin-producing secretory cell type of the intestinal epithelium. I found that goblet cells differentiate in a step-wise manner over the larval and metamorphic periods. I also determined the timing of gut looping for the intestine, a key morphological difference in the larval and adult intestine. I found that gut loops appear a short time after metamorphosis begins. In future studies, we seek to establish an assay for gut motility for studying mutant lines that have altered intestinal profiles. The zebrafish intestine may provide a robust model for understanding human intestinal physiology and disease.