ANF - A NOVEL CLASS OF VERTEBRATE HOMEOBOX GENES EXPRESSED AT THE ANTERIOR END OF THE MAIN EMBRYONIC AXIS

Five novel genes homologous to the homeobox-containing genes Xanf-1 an d Xanf-2 of Xenopus and Hesx-1/Rpx of mouse have been identified as a result of a PCR survey of cDNA in sturgeon, zebrafish, newt, chicken a nd human. Comparative analysis of the homeodomain primary structure of these genes revealed that they belong to a novel class of homeobox ge nes, which we name Anf. All genes of this class investigated so far ha ve similar patterns of expression during early embryogenesis, characte rized by maximal transcript levels being present at the anterior extre mity of the main embryonic body axis. The data obtained also suggest t hat, despite considerable high structural divergence between their hom eodomains, all known Anf genes may be orthologues, and thus represent one of the most quickly evolving classes of vertebrate homeobox genes. (C) 1997 Elsevier Science B.V.