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

First published online March 24, 2005
doi: 10.1242/10.1242/dev.01738

This Article Figures Only Full Text Full Text (PDF) 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 Blanco, J. Articles by Gehring, W. J. Search for Related Content PubMed PubMed Citation Articles by Blanco, J. Articles by Gehring, W. J.

Functional analysis of the chicken 1-crystallin enhancer activity in Drosophila reveals remarkable evolutionary conservation between chicken and fly

¹ Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland
² Institut de Génétique Humaine, Centre National de la Recherche Scientifique UPR 1142, 141 rue de la Cardonille, 34396 Montpellier, France
³ Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan

^* Author for correspondence (e-mail: Walter.Gehring{at}unibas.ch)

Accepted 3 February 2005

Functional conservation of enhancers among evolutionarily diverged organisms is a powerful way to identify basic regulatory circuits and key developmental regulators. This is especially applicable to Crystallin genes. Despite unexpected heterogeneity and diversity in their DNA sequences, many studies have revealed that most of the Crystallin genes are regulated by a relatively small set of developmentally important transcription factors. The chicken 1-crystallin is one of the best-characterized Crystallin genes. Its lens-specific regulation is governed by a 30 bp long DC5 fragment present in the third intron of the gene. DC5 contains PAX6 and SOX2 binding sites, and its activity depends on the cooperative binding of these two transcription factors. To test the idea that Pax6 and Sox2, together with the DC5 enhancer, could form a basic regulatory circuit functional in distantly related animals, we introduced the DC5 fragment into Drosophila and studied its activation pattern and regulation. The results show that the DC5 enhancer is not only active in the compound eye but, remarkably, is specifically active in those cells responsible for Crystallin secretion in Drosophila, i.e. the cone cells. However, regulation of the DC5 enhancer is carried out not by Pax6, but by Pax2 (D-Pax2; shaven – FlyBase) in combination with the Sox2 homologue SoxN. Both proteins (D-PAX2 and SOXN) bind cooperatively to the DC5 fragment and activate the enhancer synergistically. As PAX6 and PAX2 proteins derive from the same ancestor, we propose that during evolution Pax6 function in vertebrate lens development was retained by Pax2 in Drosophila.

Key words: Crystallin, Enhancer conservation, Pax6, Pax2, Sox2, SoxN, Drosophila

Related articles in Development:

A Crystallin clear view of eye evolution

Development 2005 132: e805. [Full Text]  

This article has been cited by other articles:

				J. Savare, N. Bonneaud, and F. Girard SUMO Represses Transcriptional Activity of the Drosophila SoxNeuro and Human Sox3 Central Nervous System-specific Transcription Factors Mol. Biol. Cell, June 1, 2005; 16(6): 2660 - 2669. [Abstract] [Full Text] [PDF]