The characterization of zip-1, a novel gene expressed during sexual development in Neurospora crassa

Neurospora crassa, a haploid, heterothallic, filamentous fungus is a member of the phylum Ascomycota (ascomycetes). Sexual reproduction in ascomycetes involves the differentiation of a number of tissue types. During the EST sequencing project (Neurospora Genome Project) at the University of New Mexico, a novel gene, highly expressed in fertilized sexual tissue was identified. Based on its high level of expression in sexual tissue it was postulated that the gene, zip-1 played an important function during sexual development.;Chapter one documents the computational analyses of the zip-1 gene. Web-based algorithms were used to predict the coding region of the sequence, identify similar proteins, and identify the presence of motifs, profiles, and patterns within the amino acid sequence. Results of the analyses predict that zip-1 encodes a bZIP transcription factor.;Chapter two documents the generation of zip-1 mutants by the reverse genetic technique, RIP (Repeat-Induced-Point Mutation). The zip-1 RIP mutants and zip-1 knock-outs (obtained from the University of California, Riverside, CA) were used in sexual crosses to identify sexual development defects. Results of the crosses indicate that zip-1 is not an essential gene, but may function throughout the entire period of sexual development.;Chapter three details the annotation of the N. crassa bZIP proteins. The presence of a bZIP motif was validated using motif/pattern/profile algorithms. The capacity for the proteins to attain the coiled-coil structure necessary for dimerization was predicted. The putative DNA-binding domain and leucine zipper were evaluated and compared to pattern typical of other bZIP transcription factors found in higher eukaryotic bZIP transcription factors.