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

First published online 30 September 2009
doi: 10.1242/dev.036939

This Article Figures Only Full Text Full Text (PDF) Supplementary Material All Versions of this Article: dev.036939v1 136/21/3627    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 Google Scholar Articles by Guo, Z. Articles by Wang, Z. PubMed PubMed Citation Articles by Guo, Z. Articles by Wang, Z. Pubmed/NCBI databases Substance via MeSH Social Bookmarking                         What's this?

The glypican Dally is required in the niche for the maintenance of germline stem cells and short-range BMP signaling in the Drosophila ovary

¹ Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beichen Xilu #1, Beijing 100101, P.R. China.
² Graduate School, Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100039, P.R. China.

^* Author for correspondence (zhwang{at}genetics.ac.cn)

Accepted 1 September 2009

The Drosophila ovary is an excellent system with which to study germline stem cell (GSC) biology. Two or three female GSCs are maintained in a structure called a niche at the anterior tip of the ovary. The somatic niche cells surrounding the GSCs include terminal filament cells, cap cells and escort stem cells. Mounting evidence has demonstrated that BMP-like morphogens are the immediate upstream signals to promote GSC fate by preventing the expression of Bam, a key differentiation factor. In contrast to their morphogenic long-range action in imaginal epithelia, BMP molecules in the ovarian niche specify GSC fate at single-cell resolution. How this steep gradient of BMP response is achieved remains elusive. In this study, we found that the glypican Dally is essential for maintaining GSC identity. Dally is highly expressed in cap cells. Cell-specific Dally-RNAi, mutant clonal analysis and cell-specific rescue of the GSC-loss phenotype suggest that Dally acts in the cap cells adjacent to the GSCs. We confirmed that Dally facilitated BMP signaling in GSCs by examining its downstream targets in various dally mutants. Conversely, when we overexpressed Dally in somatic cells outside the niche, we increased the number of GSC-like cells apparently by expanding the pro-GSC microenvironment. Furthermore, in a genetic setting we revealed a BMP-sensitivity distinction between germline and somatic cells, namely that Dally is required for short-range BMP signaling in germline but not in somatic cells. We propose that Dally ensures high-level BMP signaling in the ovarian niche and thus female GSC determination.

Key words: Glypican, Germline stem cell, Niche, BMP, Short-range signaling

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