A gene associated with filamentous growth in Ophiostoma novo-ulmi has RNA-binding motifs and is similar to a yeast gene involved in mRNA splicing

The COL1 ene was isolated from Ophiostoma novo-ulmi using the techniques of insertional mutagenesis and plasmid rescue. Sequence analyses suggest that the COL1 gene encodes a unique protein of 826 amino acids with consensus-t ype RNA-binding domains, most similar to a putative protein from Schizosacc haromyces pombe which resembles the C-terminus of the Saccharomyces cerevis iae U4/U6 splicing factor PRP24. Disruption of the COL1 gene produced the y east-like Loll mutant. The inability of the mutant to synthesize the COL1 g ene product was confirmed by transcript analysis. Transformation of the col 1 mutant with the COL1 gene restored the wild phenotype and production of t he 4.0-kb mRNA. The results from this study demonstrate that the COL1 RNA-b inding protein is associated with filamentous growth in O. novo-ulmi.