Formation of the digestive system in zebrafish: III. Intestinal epithelium morphogenesis

Abstract

Recent analysis of a novel strain of transgenic zebrafish (gutGFP) has provided a detailed description of the early morphological events that occur during the development of the liver and pancreas. In this paper, we aim to complement these studies by providing an analysis of the morphological events that shape the zebrafish intestinal epithelium. One of our goals is to provide a framework for the future characterization of zebrafish mutant phenotypes in which intestinal epithelial morphogenesis has been disrupted. Our analysis encompasses the period between 26 and 126 h post-fertilization (hpf) and follows the growth, lumen formation and differentiation of a continuous layer of endoderm into a functional intestinal epithelium with three morphologically distinct segments: the intestinal bulb, mid-intestine and posterior intestine. Between 26 hpf and 76 hpf, the entire intestinal endoderm is a highly proliferative organ. To make a lumen, the zebrafish endoderm cells undergo apical membrane biogenesis, adopt a bilayer configuration and form small cavities that coalesce without cell death. Thereafter, the endoderm cells polarize and differentiate into distinct cell lineages. Enteroendocrine cells are distinguished first at 52 hpf in the caudal region of the intestine in a new stable transgenic line, Tg[nkx2.2a:mEGFP]. The differentiation of mucin-containing goblet cells is first evident at 100 hpf and is tightly restricted to a middle segment of the intestine, designated the mid-intestine, that is also demarcated by the presence of enterocytes with large supranuclear vacuoles. Meanwhile, striking expansion of the lumen in the rostral intestine forms the intestinal bulb. Here the epithelium elaborates folds and proliferating cells become progressively restricted to a basal compartment analogous to the crypts of Lieberkühn in mammals. At 126 hpf, the posterior intestine remains an unfolded monolayer of simple columnar epithelium.

A chemical enterocolitis model in zebrafish larvae that is dependent on microbiota and responsive to pharmacological agents

“…Thus this model may provide an appropriate platform to probe the intersection of metabolism and immune function using small molecules and genetics. However, it is known that the larval zebrafish gut undergoes significant morphological maturation after 3 dpf as the linear gut tube undergoes convolution and folding (Wallace and Pack, 2003;Ng et al, 2005). As such, it may not be appropriate to analyze inflammationdriven changes of intestinal differentiation within such a developmentally active system Noble et al, 2008).…”

“…Larval zebrafish are experimentally accessible for the study of mucosal immunology because of their transparency and the production of large numbers of embryos. Research into zebrafish gastrointestinal function has identified many orthologous gene and signaling pathways necessary for digestive and mucosal immune function (Wallace and Pack, 2003;Ng et al, 2005;Bates et al, 2007;Flores et al, 2008).…”

The homeobox NKX and Neoplasms in Digestive system: a systematic review.

“…The largest subgroups of well-differentiated BPNETs are typical carcinoids (TCs), while within the GI tract, the small intestine (SI) is the most common site [24] . With the interest of NKX2.2 functions, Ng et al first published the research that a transgenic zebrafish line with EGFP driven by the NKX2.2a locus identifies endocrine cells in the intestine [25] . Wang et al carried out a series of studies to ascertain the role of NKX2.2 in normal and neoplastic gut.…”

Engineering Microbial Physiology with Synthetic Polymers: Cationic Polymers Induce Biofilm Formation inVibrio choleraeand Downregulate the Expression of Virulence Genes

“…[46][47][48] Zebrafish are a suitable natural host model for V. cholerae colonisation and transmission as their gastrointestinal development and physiology closely mimics that of mammalian organisms. 49 Additionally, ease of propagation and live imaging made them a good choice of host for our in vivo studies, in particular at this early . CC-BY 4.0 International license not peer-reviewed) is the author/funder.…”