Intestine of Zebrafish: Regionalization, Characterization and Stem Cells

Abstract

Unlike the mammalian digestive tract that has been developed into distinct regions for different functions, fish have a relatively simple intestine and many fishes have no recognizable stomach. We used the zebrafish microarray approach to characterize its intestine. By dividing the zebrafish intestine into seven segments along its length, we found that the first five segments resemble the mammalian small intestine and the last two segments resemble the mammalian large intestine. We then investigated the role of Notch signaling and found that a specific group of glycogen-rich fibroblasts were involved in the Notch-mediated cell fate decision process. Further, we studied the effects of radiation and found an interesting pattern of regeneration in the intestine. Moreover, the number of intestinal stem cells was investigated through a novel computational model, which was applicable not only to zebrafish, but also to mammalian intestinal tracts.