THE PENICILLIUM-CHRYSOGENUM AND ASPERGILLUS-NIDULANS WETA DEVELOPMENTAL REGULATORY GENES ARE FUNCTIONALLY EQUIVALENT

Aspergillus nidulans and Penicillium chrysogenum are related fungi tha t reproduce asexually by forming multicellular conidiophores and uninu cleate conidia. In A. nidulans, spore maturation is controlled by the wetA (AwetA) regulatory gene. We cloned a homologous gene (PwetA) from P. chrysogenum to determine if spore maturation is regulated by a sim ilar mechanism in this species. The PwetA and AwetA genes are similar in structure and functional organization. The inferred polypeptides sh are 77% overall amino acid sequence similarity, with several regions h aving > 85% similarity. The genes also had significant, local sequence similarities in their 5' flanking regions, including conserved bindin g sites for the product of the regulatory gene abaA. PwetA fully compl emented an A. nidulans wetA deletion mutation, demonstrating that Pwet A and its 5' regulatory sequences function normally in A. nidulans. Th ese results indicate that the mechanisms controlling sporulation in A, nidulans and P. chrysogenum are evolutionarily conserved.