QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 29 April 2009
doi: 10.1242/dev.032235

This Article Figures Only Full Text Full Text (PDF) Supplementary Material All Versions of this Article: dev.032235v1 136/11/1791    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Jarikji, Z. Articles by Horb, M. E. Search for Related Content PubMed PubMed Citation Articles by Jarikji, Z. Articles by Horb, M. E. Social Bookmarking                         What's this?

The tetraspanin Tm4sf3 is localized to the ventral pancreas and regulates fusion of the dorsal and ventral pancreatic buds

Zeina Jarikji^1,2,*, Lori Dawn Horb^1,2,*, Farhana Shariff¹, Craig A. Mandato³, Ken W. Y. Cho⁴ and Marko E. Horb^1,2,3,5,

¹ Laboratory of Molecular Organogenesis, Institut de Recherches Cliniques de Montréal, 110 Pine Avenue West, Montreal, QC H2W 1R7, Canada.
² Montreal Diabetes Research Center, Centre de recherche du Centre Hospitalier de l'Université de Montréal, Montreal, QC H1W 4A4, Canada.
³ Department of Anatomy and Cell Biology and Division of Experimental Medicine, McGill University, Montreal, QC Canada.
⁴ Developmental Biology Center and the Department of Developmental and Cell Biology, University of California, Irvine, CA 92697-2300, USA.
⁵ Département de médecine, Université de Montréal, Montréal, QC H3T 3J7, Canada.

Author for correspondence (e-mail: marko.horb{at}ircm.qc.ca)

Accepted 31 March 2009

During embryogenesis, the pancreas develops from separate dorsal and ventral buds, which fuse to form the mature pancreas. Little is known about the functional differences between these two buds or the relative contribution of cells derived from each region to the pancreas after fusion. To follow the fate of dorsal or ventral bud derived cells in the pancreas after fusion, we produced chimeric Elas-GFP transgenic/wild-type embryos in which either dorsal or ventral pancreatic bud cells expressed GFP. We found that ventral pancreatic cells migrate extensively into the dorsal pancreas after fusion, whereas the converse does not occur. Moreover, we found that annular pancreatic tissue is composed exclusively of ventral pancreas-derived cells. To identify ventral pancreas-specific genes that may play a role in pancreatic bud fusion, we isolated individual dorsal and ventral pancreatic buds, prior to fusion, from NF38/39 Xenopus laevis tadpoles and compared their gene expression profiles (NF refers to the specific stage of Xenopus development). As a result of this screen, we have identified several new ventral pancreas-specific genes, all of which are expressed in the same location within the ventral pancreas at the junction where the two ventral pancreatic buds fuse. Morpholino-mediated knockdown of one of these ventral-specific genes, transmembrane 4 superfamily member 3 (tm4sf3), inhibited dorsal-ventral pancreatic bud fusion, as well as acinar cell differentiation. Conversely, overexpression of tm4sf3 promoted development of annular pancreas. Our results are the first to define molecular and behavioral differences between the dorsal and ventral pancreas, and suggest an unexpected role for the ventral pancreas in pancreatic bud fusion.

Key words: Xenopus, Pancreatic bud, Tm4sf3, Tetraspanin, Annular pancreas

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?