Vol. 38 No. 4, 1999

What the Cnidaria Tell Us about Pax Gene Evolution

David J. Miller

Department of Biochemistry and Molecular Biology, James Cook University, Townsville, Queensland 4811, Australia

David J. Miller (1999) Pax genes are defined by the possession of a motif that was first identified in the Drosophila segmentation gene paired. They encode transcription factors often containing a homeodomain (or a part of it) as well as the paired domain. Genes in this family play central roles in the development of animals; however, the complexity of the family – 9 human and 8 Drosophila Pax genes are now known – and the diversity of their functions has effectively obscured the identification of functional homology between different organisms. The availability of data on a numberof Pax genes in cnidarians should facilitate unravelling the complex evolutionary history of the Pax gene family. This review makes use of the cnidarian data and the extensive genomic sequence data now available for the nematode Caenorhabditis to propose a model for evolution of the various Pax gene types.

Key words: Development, Paired, Pax, Evolution, Cnidaria.

*Correspondence: Tel: 61-7-47814473. Fax: 61-7-47251394. E-mail: david.miller@jcu.edu.au