John Vierula

Biography

John Vierula Associate Professor Degrees: B.Sc. (York), Ph.D. (Calgary), Post Doc (Guelph)

Research Interest

Filamentous fungi such as Neurospora crassa grow by apical extension of hyphal tip cells. Perturbations in any of the processes required for tip growth are readily apparent since they result in an aberrant colony morphology. To learn more about the molecular biology of tip growth, we are cloning genes which are required for normal colony morphology. In addition to standard cloning and sequence analysis, we use microscopy and a variety of biochemical approaches to deduce the function of the products of these genes. For example, one group of morphological mutants known as ropy have defective nuclear migration in their hyphae. One of the genes we have analysed, ropy-4, encodes an actin-related protein (centractin) which is part of the dynactin activating complex for the microtubule-based motor protein known as cytoplasmic dynein. The ropy-2 gene codes for p62, a centractin capping protein of the dynactin/dynein motor assembly. Another interesting mutant strain (cot-3), which forms small colonies at elevated temperatures, has a mutation in the gene encoding elongation factor 2 (EF-2).