Proteins, morphology, and genetics in Neurospora

Abstract

The proteins of Neurospora have been extracted and then separated by acrylamide gel electrophoresis. A general stain (amido black) reveals the complement of both positively and negatively charged proteins which are separable on the gels into many components arranged in recognizable patterns. Tests for proteins which have enzyme action (esterases) have permitted attention to be focused more specifically upon particular proteins. The objective was to study the proteins of Neurospora as they are affected by its genetic constitution and especially by mutant genes which determine the morphology of the organism in culture. In the outcome, single genes exerted marked and recognizable effects on the detectable protein patterns, and their effect was apparent even against different genetic backgrounds. By controlled breeding experiments and using mycelial cultures raised from each of the spores, which were removed serially from a single ascus from a given cross, it has been established that various mutants at the peak locus (including bis) affect the form and the protein composition of the organism simultaneously. Chemical treatments which rendered the genetically different cultures phenotypically similar have been used with the result that the many protein changes observed are interpreted as the consequence, not the primary cause, of the morphology of the mutant strain. In this and other ways, e.g., by observing the soluble nitrogen compounds and the nucleic acids, it is concluded that the condition described as peak is brought about by a single gene that nevertheless carries with it a great variety of biochemical consequences which appear concomitantly with the morphology imposed upon the organism.