Identification, visualization and clonal analysis of intestinal stem cells in fish

Recently, a stochastic model of symmetrical stem cell division followed by neutral drift has been proposed for intestinal stem cells (ISCs). This division mode has been suggested to represent the predominant mode of stem cell progression in mammals. In contrast, stem cells in the retina of teleost fish show a preferential asymmetric division mode. To address whether the mode of stem cell division is following phylogenetic or ontogenetic routes we characterized and analysed the entire gastrointestinal system with a particular focus on ISCs in the teleost medaka (Oryzias latipes). We analysed the entire intestine in adult medaka by X-ray micro-computed tomography within the intact body and combined that analysis with the cellular and molecular composition of the intestinal system. This allowed correlating the 3D topography with functional domains of the intestinal system. Morphology and gene expression data consistently argue for a subdivision of the medaka intestine into a small and larg...