DNA-binding characteristics of cnidarian Pax-C and Pax-B proteins in vivo and in vitro: No simple relationship with the Pax-6 and Pax-2/5/8 classes

• Published in: Journal of experimental zoology. Part B, Molecular and developmental evolution Molecular and developmental evolution, 2003-10, Vol.299B (1), p.26-35
• Main Authors: Plaza, Serge, De Jong, Danielle M., Gehring, Walter J., Miller, David J.
• Format: Article
• Language: English
• Subjects: Acropora; Animals; Anthozoa - genetics; DNA Primers; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - genetics; Drosophila; Drosophila Proteins - genetics; Drosophila Proteins - physiology; Embryonic Induction - genetics; Eye - embryology; Eye Proteins - physiology; Gene Expression - genetics; Homeodomain Proteins - chemistry; Homeodomain Proteins - genetics; Homeodomain Proteins - physiology; In Vitro Techniques; Morphogenesis - genetics; Nuclear Proteins; Paired Box Transcription Factors; PAX2 Transcription Factor; PAX5 Transcription Factor; PAX6 Transcription Factor; Recombinant Fusion Proteins - genetics; Repressor Proteins; Trans-Activators - chemistry; Trans-Activators - genetics; Transcription Factors - chemistry; Transcription Factors - genetics
• ISSN: 1552-5007; 0022-104X; 1552-5015
• DOI: 10.1002/jez.b.38

Cnidarians are the simplest animals in which distinct eyes are present. We have previously suggested that cnidarian Pax‐Cam might represent a precursor of the Pax‐6 class. Here we show that when expressed in Drosophila imaginal discs, Pax‐Cam chimeric proteins containing the C‐terminal region of EY were capable of eye induction and driving expression of a reporter gene under the control of a known EY target (the sine oculis gene). Whilst these results are consistent with a Pax‐6‐like function for Pax‐Cam, in band shift experiments we were unable to distinguish the DNA‐binding behaviour of the Pax‐Cam Paired domain from that of a second Acropora Pax protein, Pax‐Bam. The ability of a Pax‐Bam/EY chimera to also induce eye formation in leg imaginal discs, together with the in vitro data, cast doubt on previously assumed direct relationships between cnidarian Pax genes and the Pax‐6 and Pax‐2/5/8 classes of bilateral animals. J. Exp. Zool. (Mol. Dev. Evol.) 299B:26–35, 2003. © 2003 Wiley‐Liss, Inc.