Abnormal Nuclear Pore Formation Triggers Apoptosis in the Intestinal Epithelium of elys-Deficient Zebrafish

• Type of Material: Article
• Authors: Tanya A. de Jong-Curtain, Royal Melbourne Hospital; Adam C. Parslow, Royal Melbourne Hospital; Andrew J. Trotter, Royal Melbourne Hospital; Nathan E. Hall, Royal Melbourne Hospital; Heather Verkade, Royal Melbourne Hospital; Tania Tabone, Royal Melbourne Hospital; Elizabeth L. Christie, Royal Melbourne Hospital; Monica O. Crowhurst, Royal Melbourne Hospital; Judith E. Layton, Walter and Eliza Hall Institute of Medical Research; Iain Shepherd, Emory University; Susan J. Nixon, University of Queensland; Robert G. Parton, University of Queensland; Leonard I. Zon, Children's Hospital Boston; Didier Y. R. Stainier, University of California, San Francisco; Graham J. Lieschke, Walter and Eliza Hall Institute of Medical Research; Joan K. Heath, Royal Melbourne Hospital
• Language: English
• Date: 2009-01-01
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2009 AGA Institute.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1053/j.gastro.2008.11.012
• Title of Journal or Parent Work: Gastroenterology
• ISSN: 0016-5085
• Volume: 136
• Issue: 3
• Start Page: 902
• End Page: 911
• Grant/Funding Information: This work was supported by NHMRC Australia project grants 280916 and 433614 (JKH); NHMRC Dora Lush (Biomedical) Scholarship (TADJ-C); NHMRC Howard Florey Centenary Fellowship (HV); Australian Research Council grant DP0346823 (GJL); and NIH grants DK 067285 (ITS), K058181 and DK060322 (DYRS).
• Keywords: Microscopy, Electron; Intestines; Gene Expression Regulation, Developmental; Enteric Nervous System; Nuclear Pore; Zebrafish Proteins; Eye Abnormalities; Cell Differentiation; Phenotype; Zebrafish; Apoptosis; Nuclear Pore Complex Proteins; Cell Lineage; Animals; Liver; Pancreas; Intestinal Mucosa
• Research Categories: Biology, Genetics; Biology, Cell

Abstract

Background & Aims: Zebrafish mutants generated by ethylnitrosourea-mutagenesis provide a powerful tool for dissecting the genetic regulation of developmental processes, including organogenesis. One zebrafish mutant, "flotte lotte" (flo), displays striking defects in intestinal, liver, pancreas, and eye formation at 78 hours postfertilization (hpf). In this study, we sought to identify the underlying mutated gene in flo and link the genetic lesion to its phenotype. Methods: Positional cloning was employed to map the flo mutation. Subcellular characterization of flo embryos was achieved using histology, immunocytochemistry, bromodeoxyuridine incorporation analysis, and confocal and electron microscopy. Results: The molecular lesion in flo is a nonsense mutation in the elys (embryonic large molecule derived from yolk sac) gene, which encodes a severely truncated protein lacking the Elys C-terminal AT-hook DNA binding domain. Recently, the human ELYS protein has been shown to play a critical, and hitherto unsuspected, role in nuclear pore assembly. Although elys messenger RNA (mRNA) is expressed broadly during early zebrafish development, widespread early defects in flo are circumvented by the persistence of maternally expressed elys mRNA until 24 hpf. From 72 hpf, elys mRNA expression is restricted to proliferating tissues, including the intestinal epithelium, pancreas, liver, and eye. Cells in these tissues display disrupted nuclear pore formation; ultimately, intestinal epithelial cells undergo apoptosis. Conclusions: Our results demonstrate that Elys regulates digestive organ formation.