IDENTIFICATION OF THE FIRST FUNGAL ANNEXIN - ANALYSIS OF ANNEXIN GENEDUPLICATIONS AND IMPLICATIONS FOR EUKARYOTIC EVOLUTION

Annexin homologues have been found in animals, plants, and distinct pr otist lineages. We report the identification of the first fungal annex in, encoded by the anx14 gene of the filamentous ascomycete Neurospora crassa, Annexins have a complex evolutionary history and exhibit a la rge number of gene duplications and gene losses in various taxa, inclu ding the complete loss of annexin sequences from another ascomycete, t he budding yeast Saccharomyces cerevisiae. Surprisingly, the N. crassa annexin homologue is most closely related to the annexin homologue of the slime mold Dictyostelium discoideum, suggesting a phylogenetic li nk between cellular slime molds and true fungi. Both of these annexin homologues are closely related to the family of annexin homologues pre sent in animals, an observation consistent with the existence of the a nimal-fungal clade. These data further suggest that the gene duplicati ons that generated the family of annexin sequences present in animals, fungi, and slime molds began prior to the divergence of these taxa.