UBC Theses and Dissertations
Gene interactions during Neurospora development Gavric, Olivera
There are more than 100 loci that encode products that can affect tip growth and branching in Neurospora crassa. In order to dissect the genetics of branching the functional relationship between 36 of those loci have been examined. By using epistasis analysis some of these genes were grouped into common developmental pathways. Double mutants were obtained through ascus analysis. In most cases double mutants show a phenotype more severe than either single mutant alone, indicating that each mutant probably affects separate pathways involved in hyphal tip growth and branching. Several double mutants were found to closely resemble one of the parental strains in hyphal morphology. This suggests both genes are part of a single developmental pathway, with the epistatic gene acting before the hypostatic one. However, about half of the double mutants obtained in this study did not fit the traditional view of epistasis. The presented analysis gave a provisional characterization of four pathways involved in tip growth and branching. In addition, all these morphogenes were phenotypicaly characterized and screened for their response to exogenous Ca²⁺ and Mn²⁺. Mutant phenotypes of snowflake, smco-1 and smco-6 were corrected to wild type phenotype either by addition of exogenous Ca²⁺ or Mn²⁺. Some mutants were partially corrected by only Ca²⁺ or Mn²⁺. Also, growth of several mutants was inhibited either by Ca²⁺ or Mn²⁺or both.
Item Citations and Data