It is unclear how widespread the antizyme gene is within the fungal kingdom. We have identi®ed and cloned antizyme homologs from two other ®ssion yeasts (Schizosaccharomyces octosporus and Schizosaccharomyces japonicus) and from two distantly related fungi (Botryotinia fuckeliana and Emericella nidulans) (our unpublished results). The antizyme frameshift site of the latter two fungi has evolved in a unique way different from all other known antizymes, but nevertheless even these two distantly related fungi have conserved the autoregulatory +1 frameshifting. The fact that the yeast S.pombe has an antizyme gene suggests the possibility that the higher eukaryotic metazoans may all have an antizyme gene.