Student Research Projects

Exploring the Effects of Gene Mutations on the Common Mold, Neurospora Crass

Student Whitney Symons, ‘15
Faculty Mentor(s)
Department Biology
Course BIO 400: Scanning Electron Microscopy (SEM)


Relatively little is known about the microanatomy of mutant strains of the common mold, Neurospora crass. In this study, I used scanning electron microscopy (SEM) to examine five mutants, including strain 9820 (an acting gene mutant), strain 9745 (a ‘rho-type GTPase’ mutant), strain 9776 (a mutant in a ‘PI4-P5 kinase’), strain 9886 (a protein kinase mutant), and the strain 185 (unkown gene alteration). Fungi were grown on MV media for 20 hrs at 30°C prior to fixation in Trump's fixative and 1% osmium tetroxide. For strain 185 and strain 9820, I observed that the growth rates were slower in comparison to the other strands, 9776, 9745, and 9820. For strain 9886, I found swollen hyphae, and cell junctions that appear to be incomplete. Whereas, in strain 185, I found that the cell junctions were thick, and the hyphae were uniform in shape. For strain 9745, I found the hyphae to have a sinusoidal pattern, a bulbous shape, and the cell junctions were round with slight protrusions. For strain 9776, I found the morphology of the hypha to be relatively straight, with long filaments and branching. The cell junctions for the strain 9776 appear to vary in shape, but maintain a solid ring like structure with a few incomplete junctions. The bulbous hyphae that were found in strain 9745 supports previous observations of the strand. The strains of these mutant fungi have not been extensively studied, and some strains, like 9776, have been not been observed with SEM. This study helps to better understand the microanatomy