Genes expressed during conidiation inNeurospora crassa: characterization ofcon-8

The filamentous fungus Neurospora crassa, by a series of defined changes, differentiates from a mycelium composed of branching hyphae to form dormant spores, called conidia. Several genes of unknown function (con genes) that are preferentially expressed during this period have been cloned. Transcription of these genes has been examined in conidiation-defective mutants, and the results obtained revealed that con-6, con-8, con-10, con-11 and con-13 are most likely to play a unique role during conidiation, con-8 is expressed early during conidial differentiation. Genomic and cDNA sequence analyses with con-8 clones identified one open reading frame, interrupted by two introns, which encodes a weakly acidic 18.4 kDa polypeptide containing 176 amino acid residues, con-8 is unusual in that it is transcribed as two mRNA species, 1.0 and 1.25 kb in length. S1 nuclease mapping and primer extension analyses identify one major initiation site, one major polyadenylation site, and demonstrated the existence of heterogeneity at the messenger's 5' and 3' ends.