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

First published online May 23, 2006
doi: 10.1242/10.1242/dev.02400

This Article Figures Only Full Text Full Text (PDF) Supplementary Material Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in Development 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Akiyama-Oda, Y. Articles by Oda, H. Search for Related Content PubMed PubMed Citation Articles by Akiyama-Oda, Y. Articles by Oda, H.

Axis specification in the spider embryo: dpp is required for radial-to-axial symmetry transformation and sog for ventral patterning

¹ JT Biohistory Research Hall, 1-1 Murasaki-cho, Takatsuki, Osaka 569-1125, Japan.
² PRESTO, Japan Science and Technology Agency, Saitama, Japan.

^* Authors for correspondence (e-mail: yasuko{at}brh.co.jp and hoda{at}brh.co.jp)

Accepted 10 April 2006

The mechanism by which Decapentaplegic (Dpp) and its antagonist Short gastrulation (Sog) specify the dorsoventral pattern in Drosophila embryos has been proposed to have a common origin with the mechanism that organizes the body axis in the vertebrate embryo. However, Drosophila Sog makes only minor contributions to the development of ventral structures that hypothetically correspond to the vertebrate dorsum where the axial notochord forms. In this study, we isolated a homologue of the Drosophila sog gene in the spider Achaearanea tepidariorum, and characterized its expression and function. Expression of sog mRNA initially appeared in a radially symmetrical pattern and later became confined to the ventral midline area, which runs axially through the germ band. RNA interference-mediated depletion of the spider sog gene led to a nearly complete loss of ventral structures, including the axial ventral midline and the central nervous system. This defect appeared to be the consequence of dorsalization of the ventral region of the germ band. By contrast, the extra-embryonic area formed normally. Furthermore, we showed that embryos depleted for a spider homologue of dpp failed to break the radial symmetry, displaying evenly high levels of sog expression except in the posterior terminal area. These results suggest that dpp is required for radial-to-axial symmetry transformation of the spider embryo and sog is required for ventral patterning. We propose that the mechanism of spider ventral specification largely differs from that of the fly. Interestingly, ventral specification in the spider is similar to the process in vertebrates in which the antagonism of Dpp/BMP signaling plays a central role in dorsal specification.

Key words: Spider, Embryogenesis, dpp, sog, Antagonist, Body axis formation, RNAi

Related articles in Development:

Spinning a developmental story

Development 2006 133: e1204. [Full Text]  

This article has been cited by other articles:

				H. Oda, O. Nishimura, Y. Hirao, H. Tarui, K. Agata, and Y. Akiyama-Oda Progressive activation of Delta-Notch signaling from around the blastopore is required to set up a functional caudal lobe in the spider Achaearanea tepidariorum Development, June 15, 2007; 134(12): 2195 - 2205. [Abstract] [Full Text] [PDF]

				M. v. d. Zee, O. Stockhammer, C. v. Levetzow, R. N. d. Fonseca, and S. Roth Sog/Chordin is required for ventral-to-dorsal Dpp/BMP transport and head formation in a short germ insect PNAS, October 31, 2006; 103(44): 16307 - 16312. [Abstract] [Full Text] [PDF]